@article {pmid38759062,
year = {2024},
author = {Jiang, W and Zhang, Y and Yan, J and He, Z and Chen, W},
title = {Differences of protein expression in enterococcus faecalis biofilm during resistance to environmental pressures.},
journal = {Technology and health care : official journal of the European Society for Engineering and Medicine},
volume = {},
number = {},
pages = {},
doi = {10.3233/THC-248033},
pmid = {38759062},
issn = {1878-7401},
abstract = {BACKGROUND: Enterococcus faecalis biofilm was frequently found on the failed treated root canal wall, which survived by resisting disinfectant during endodontic treatment.Many researches have been conducted to explore the mechanisms of persistence of this pathogen in unfavorable conditions. However, no comprehensive proteomics studies have been conducted to investigate stress response in Enterococcus faecalis caused by alkali and NaOCl.

OBJECTIVE: Enterococcus faecalis (E.f) has been recognized as a main pathogen of refractory apical periodontitis, its ability to withstand environmental pressure is the key to grow in the environment of high alkaline and anti-bacterial drug that causes chronic infection in the root canal. This study aims to focus on the protein expression patterns of E.f biofilm under extreme pressure environment".

METHODS: Enterococcus faecalis biofilm model was established in vitro. Liquid Chromatograph-Mass Spectrometer (LC-MS/MS)-based label free quantitative proteomics approach was applied to compare differential protein expression under different environmental pressures (pH 10 and 5% sodium hypochlorite (NaOCl)). And then qPCR and Parallel Reaction Monitoring Verification (PRM) were utilized to verify the consequence of proteomics.

RESULTS: The number of taxa in this study was higher than those in previous studies, demonstrating the presence of a remarkable number of proteins in the groups of high alkaline and NaOCl. Proteins involved in ATP-binding cassette (ABC) transporter were significantly enriched in experimental samples. We identified a total of 15 highly expressed ABC transporters in the high alkaline environment pressure group, with 7 proteins greater than 1.5 times.

CONCLUSIONS: This study revealed considerable changes in expression of proteins in E.f biofilm during resistance to environmental pressures. The findings enriched our understanding of association between the differential expression proteins and environmental pressures.},
}

@article {pmid38758746,
year = {2024},
author = {Jang, H and Song, W and Song, H and Kang, DK and Park, S and Seong, M and Jeong, HE},
title = {Sustainable Biofilm Inhibition Using Chitosan-Mesoporous Nanoparticle-Based Hybrid Slippery Composites.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.4c03053},
pmid = {38758746},
issn = {1944-8252},
abstract = {In recent decades, extensive research has been directed toward mitigating microbial contamination and preventing biofilm formation. However, many conventional antibiofilm methods rely on hazardous and toxic substances, neglecting potential risks to human health and the environment. Moreover, these approaches often rely on single-strategy mechanisms, utilizing either bactericidal or fouling-resistant agents, which have shown limited efficacy in long-term biofilm suppression. In this study, we propose an efficient and sustainable biofilm-resistant slippery hybrid slippery composite. This composite integrates nontoxic and environmentally friendly materials including chitosan, silicone oil-infused polydimethylsiloxane, and mesoporous silica nanoparticles in a synergistic manner. Leveraging the bacteria-killing properties of chitosan and the antifouling capabilities of the silicone oil layer, the hybrid composite exhibits robust antibiofilm performance against both Gram-positive and Gram-negative bacteria. Furthermore, the inclusion of mesoporous silica nanoparticles enhances the oil absorption capacity and self-replenishing properties, ensuring exceptional biofilm inhibition even under harsh conditions such as exposure to high shear flow and prolonged incubation (7 days). This approach offers promising prospects for developing effective biofilm-resistant materials with a reduced environmental impact and improved long-term performance.},
}

@article {pmid38755634,
year = {2024},
author = {Wongchai, M and Wongkaewkhiaw, S and Kanthawong, S and Roytrakul, S and Aunpad, R},
title = {Dual-function antimicrobial-antibiofilm peptide hybrid to tackle biofilm-forming Staphylococcus epidermidis.},
journal = {Annals of clinical microbiology and antimicrobials},
volume = {23},
number = {1},
pages = {44},
pmid = {38755634},
issn = {1476-0711},
support = {13/2563//National Research Council of Thailand (NRCT)/ ; },
mesh = {*Biofilms/drug effects ; *Staphylococcus epidermidis/drug effects/physiology ; Humans ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology/chemistry ; Hemolysis/drug effects ; Antimicrobial Peptides/pharmacology/chemistry ; Staphylococcal Infections/drug therapy/microbiology ; },
abstract = {BACKGROUND: Due to their resistance and difficulty in treatment, biofilm-associated infections are problematic among hospitalized patients globally and account for 60% of all bacterial infections in humans. Antibiofilm peptides have recently emerged as an alternative treatment since they can be effectively designed and exert a different mode of biofilm inhibition and eradication.

METHODS: A novel antibiofilm peptide, BiF, was designed from the conserved sequence of 18 α-helical antibiofilm peptides by template-assisted technique and its activity was improved by hybridization with a lipid binding motif (KILRR). Novel antibiofilm peptide derivatives were modified by substituting hydrophobic amino acids at positions 5 or 7, and both, with positively charged lysines (L5K, L7K). These peptide derivatives were tested for antibiofilm and antimicrobial activities against biofilm-forming Staphylococcus epidermidis and multiple other microbes using crystal violet and broth microdilution assays, respectively. To assess their impact on mammalian cells, the toxicity of peptides was determined through hemolysis and cytotoxicity assays. The stability of candidate peptide, BiF2_5K7K, was assessed in human serum and its secondary structure in bacterial membrane-like environments was analyzed using circular dichroism. The action of BiF2_5K7K on planktonic S. epidermidis and its effect on biofilm cell viability were assessed via viable counting assays. Its biofilm inhibition mechanism was investigated through confocal laser scanning microscopy and transcription analysis. Additionally, its ability to eradicate mature biofilms was examined using colony counting. Finally, a preliminary evaluation involved coating a catheter with BiF2_5K7K to assess its preventive efficacy against S. epidermidis biofilm formation on the catheter and its surrounding area.

RESULTS: BiF2_5K7K, the modified antibiofilm peptide, exhibited dose-dependent antibiofilm activity against S. epidermidis. It inhibited biofilm formation at subinhibitory concentrations by altering S. epidermidis extracellular polysaccharide production and quorum-sensing gene expression. Additionally, it exhibited broad-spectrum antimicrobial activity and no significant hemolysis or toxicity against mammalian cell lines was observed. Its activity is retained when exposed to human serum. In bacterial membrane-like environments, this peptide formed an α-helix amphipathic structure. Within 4 h, a reduction in the number of S. epidermidis colonies was observed, demonstrating the fast action of this peptide. As a preliminary test, a BiF2_5K7K-coated catheter was able to prevent the development of S. epidermidis biofilm both on the catheter surface and in its surrounding area.

CONCLUSIONS: Due to the safety and effectiveness of BiF2_5K7K, we suggest that this peptide be further developed to combat biofilm infections, particularly those of biofilm-forming S. epidermidis.},
}

*Biofilms/drug effects
*Staphylococcus epidermidis/drug effects/physiology
Humans
*Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology/chemistry
Hemolysis/drug effects
Antimicrobial Peptides/pharmacology/chemistry
Staphylococcal Infections/drug therapy/microbiology

@article {pmid38755426,
year = {2024},
author = {Lopes, APR and Andrade, AL and Pinheiro, AA and de Sousa, LS and Malveira, EA and Oliveira, FFM and de Albuquerque, CC and Teixeira, EH and de Vasconcelos, MA},
title = {Lippia grata Essential Oil Acts Synergistically with Ampicillin Against Staphylococcus aureus and its Biofilm.},
journal = {Current microbiology},
volume = {81},
number = {7},
pages = {176},
pmid = {38755426},
issn = {1432-0991},
support = {APQ-00224-2//Fundação de Amparo à Pesquisa do Estado de Minas Gerais/ ; APQ-02972-22//Fundação de Amparo à Pesquisa do Estado de Minas Gerais/ ; },
mesh = {*Biofilms/drug effects ; *Staphylococcus aureus/drug effects/physiology ; *Ampicillin/pharmacology ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology ; *Drug Synergism ; *Oils, Volatile/pharmacology ; *Lippia/chemistry ; Plant Extracts/pharmacology ; Plant Leaves/chemistry ; },
abstract = {Antimicrobial resistance (AMR) presents a global challenge as microorganisms evolve to withstand the effects of antibiotics. In addition, the improper use of antibiotics significantly contributes to the AMR acceleration. Essential oils have garnered attention for their antimicrobial potential. Indeed, essential oils extracted from plants contain compounds that exhibit antibacterial activity, including against resistant microorganisms. Hence, this study aimed to evaluate the antimicrobial and antibiofilm activity of the essential oil (EO) extracted from Lippia grata and its combination with ampicillin against Staphylococcus aureus strains (ATCC 25923, ATCC 700698, and JKD6008). The plant material (leaves) was gathered in Mossoro, RN, and the EO was obtained using the hydrodistillation method with the Clevenger apparatus. The antimicrobial activity of the EO was assessed through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Antibiofilm activity was evaluated by measuring biomass using crystal violet (CV) staining, viable cell counting, and analysis of preformed biofilms. In addition, the synergistic effects of the EO in combination with ampicillin were examined by scanning electron and confocal microscopy. The EO displayed a MIC value of 2.5 mg/mL against all tested S. aureus strains and an MBC only against S. aureus JKD6008 at 2.5 mg/mL. L. grata EO caused complete biofilm inhibition at concentrations ranging from 10 to 0.312 mg/mL against S. aureus ATCC 25923 and 10 to 1.25 mg/mL against S. aureus ATCC 700698 and S. aureus JKD6008. In the viable cell quantification assay, there was a reduction in CFU ranging from 1.0 to 8.0 logs. The combination of EO with ampicillin exhibited a synergistic effect against all strains. Moreover, the combination showed a significantly inhibiting biofilm formation and eradicating preformed biofilms. Furthermore, the EO and ampicillin (individually and in combination) altered the cellular morphology of S. aureus cells. Regarding the mechanism, the results revealed that L. grata EO increased membrane permeability and caused significant membrane damage. Concerning the synergy mechanism, the results revealed that the combination of EO and ampicillin increases membrane permeability and causes considerable membrane damage, further inhibiting bacteria synergistically. The findings obtained here suggest that L. grata EO in combination with ampicillin could be a viable treatment option against S. aureus infections, including MRSA strain.},
}

*Biofilms/drug effects
*Staphylococcus aureus/drug effects/physiology
*Ampicillin/pharmacology
*Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology
*Drug Synergism
*Oils, Volatile/pharmacology
*Lippia/chemistry
Plant Extracts/pharmacology
Plant Leaves/chemistry

@article {pmid38755164,
year = {2024},
author = {Fernández-Calvet, A and Matilla-Cuenca, L and Izco, M and Navarro, S and Serrano, M and Ventura, S and Blesa, J and Herráiz, M and Alkorta-Aranburu, G and Galera, S and Ruiz de Los Mozos, I and Mansego, ML and Toledo-Arana, A and Alvarez-Erviti, L and Valle, J},
title = {Gut microbiota produces biofilm-associated amyloids with potential for neurodegeneration.},
journal = {Nature communications},
volume = {15},
number = {1},
pages = {4150},
pmid = {38755164},
issn = {2041-1723},
support = {PC133-134-135 MICROPROGEN//Departamento de Educación, Gobierno de Navarra (Department of Education, Government of Navarra)/ ; },
mesh = {Animals ; *Gastrointestinal Microbiome ; *Caenorhabditis elegans/metabolism/microbiology ; Humans ; *Biofilms/growth & development ; *Amyloid/metabolism ; *alpha-Synuclein/metabolism/genetics ; *Parkinson Disease/metabolism/microbiology/pathology ; Mice ; *Dopaminergic Neurons/metabolism ; Autophagy ; Neurodegenerative Diseases/metabolism ; Mice, Inbred C57BL ; Bacterial Proteins/metabolism/genetics ; Brain/metabolism/pathology ; Synucleinopathies/metabolism/pathology ; },
abstract = {Age-related neurodegenerative diseases involving amyloid aggregation remain one of the biggest challenges of modern medicine. Alterations in the gastrointestinal microbiome play an active role in the aetiology of neurological disorders. Here, we dissect the amyloidogenic properties of biofilm-associated proteins (BAPs) of the gut microbiota and their implications for synucleinopathies. We demonstrate that BAPs are naturally assembled as amyloid-like fibrils in insoluble fractions isolated from the human gut microbiota. We show that BAP genes are part of the accessory genomes, revealing microbiome variability. Remarkably, the abundance of certain BAP genes in the gut microbiome is correlated with Parkinson's disease (PD) incidence. Using cultured dopaminergic neurons and Caenorhabditis elegans models, we report that BAP-derived amyloids induce α-synuclein aggregation. Our results show that the chaperone-mediated autophagy is compromised by BAP amyloids. Indeed, inoculation of BAP fibrils into the brains of wild-type mice promote key pathological features of PD. Therefore, our findings establish the use of BAP amyloids as potential targets and biomarkers of α-synucleinopathies.},
}

Animals
*Gastrointestinal Microbiome
*Caenorhabditis elegans/metabolism/microbiology
Humans
*Biofilms/growth & development
*Amyloid/metabolism
*alpha-Synuclein/metabolism/genetics
*Parkinson Disease/metabolism/microbiology/pathology
Mice
*Dopaminergic Neurons/metabolism
Autophagy
Neurodegenerative Diseases/metabolism
Mice, Inbred C57BL
Bacterial Proteins/metabolism/genetics
Brain/metabolism/pathology
Synucleinopathies/metabolism/pathology

@article {pmid38755018,
year = {2024},
author = {Daca, A and Piechowicz, L and Wiśniewska, K and Bryl, E and Witkowski, JM and Jarzembowski, T},
title = {Both biofilm cytotoxicity and monocytes' adhesion may be used as estimators of enterococcal virulence.},
journal = {Letters in applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/lambio/ovae047},
pmid = {38755018},
issn = {1472-765X},
abstract = {Our study aimed to identify markers of enterococci's virulence potential by evaluating the properties of strains of different sites of isolation. Enterococcal strains were isolated as commensals from faeces and as invasive strains from the urine and blood of patients from the University Clinical Centre, Gdańsk, Poland. Changes in monocytes' susceptibility to the cytotoxic activity of isolates of different origins and their adherence to biofilm were evaluated using a flow cytometer. The bacterial protein profile was estimated by MALDI-TOF MS. The cytotoxicity of biofilm and monocytes' adherence to it were the most accurate factors in predicting the prevalence of the strain in the specific niche. Additionally, a bacterial protein with mass-to-charge ratio (m/z) 5000 was found to be responsible for the increased bacterial cytotoxicity, while monocytes' decreased adherence to biofilm was linked with the presence of proteins either with m/z 3330 or 2435. The results illustrate that monocytes' reaction when exposed to the bacterial biofilm can be used as an estimator of pathogens' virulence potential. The observed differences in monocytes' response are explainable, by the bacterial proteins' profile. Additionally, the results indicate that the features of both bacteria and monocytes impact the outcome of the infection.},
}

@article {pmid38752875,
year = {2024},
author = {Sun, Y and Zhao, H and Pu, F and Liu, H and Chen, L and Ren, J and Qu, X},
title = {On-Demand Activatable and Integrated Bioorthogonal Nanocatalyst against Biofilm-Associated Infections.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2400899},
doi = {10.1002/adhm.202400899},
pmid = {38752875},
issn = {2192-2659},
abstract = {Bioorthogonal chemistry has emerged as a powerful tool for manipulating biological processes. However, difficulties in controlling the exact location and on-demand catalytic synthesis limit its application in biological systems. Herein, we constructed an activatable bioorthogonal system integrating a shielded catalyst and prodrug molecules to combat biofilm-associated infections. The catalytic species is activated in response to the hyaluronidase (HAase) secreted by the bacteria and the acidic pH of the biofilm, which is accompanied by the release of prodrugs, to achieve the bioorthogonal catalytic synthesis of antibacterial molecules in situ. Moreover, the system can produce reactive oxygen species (ROS) to disperse bacterial biofilms, enabling the antibacterial molecules to penetrate the biofilm and eliminate the bacteria within it. This study promotes the design of efficient and safe bioorthogonal catalysts and the development of bioorthogonal chemistry-mediated antibacterial strategies. This article is protected by copyright. All rights reserved.},
}

@article {pmid38752844,
year = {2024},
author = {Bhatt, P and Sharpe, A and Staines, K and Wallace, N and Withers, A},
title = {Topical desiccating agent (DEBRICHEM): an accessible debridement option for removing biofilm in hard-to-heal wounds.},
journal = {Journal of wound care},
volume = {33},
number = {Sup5b},
pages = {S4-S11},
doi = {10.12968/jowc.2024.33.Sup5b.S4},
pmid = {38752844},
issn = {0969-0700},
mesh = {Humans ; *Biofilms ; *Debridement/methods ; *Wound Healing ; Wound Infection/therapy ; Administration, Topical ; Wounds and Injuries/therapy ; },
abstract = {It is now assumed that all hard-to-heal wounds contain biofilm. Debridement plays a key role in wound-bed preparation, as it can remove biofilm along with the devitalised tissue, potentially leaving a clean wound bed that is more likely to progress towards healing. The gold standard methods of debridement (surgical and sharp) are the least used, as they require specialist training and are often not readily available at the point of need. Most other methods can be used by generalists but are slower. They all need regular applications. The topical desiccating agent DEBRICHEM is an innovative alternative, as it is fast, effective and can be used in all clinical settings, as well as typically requiring only a single use. This article describes best practice for achieving optimal outcomes with its use.},
}

Humans
*Biofilms
*Debridement/methods
*Wound Healing
Wound Infection/therapy
Administration, Topical
Wounds and Injuries/therapy

@article {pmid38751998,
year = {2024},
author = {Shang, X and Bai, H and Fan, L and Zhang, X and Zhao, X and Liu, Z},
title = {In vitro biofilm formation of Gardnerella vaginalis and Escherichia coli associated with bacterial vaginosis and aerobic vaginitis.},
journal = {Frontiers in cellular and infection microbiology},
volume = {14},
number = {},
pages = {1387414},
pmid = {38751998},
issn = {2235-2988},
mesh = {*Biofilms/growth & development ; *Gardnerella vaginalis/physiology/growth & development ; Humans ; *Escherichia coli/physiology ; Female ; *Vaginosis, Bacterial/microbiology ; *Microscopy, Electron, Scanning ; Microscopy, Confocal ; Vagina/microbiology ; Anaerobiosis ; Coculture Techniques ; Vaginitis/microbiology ; },
abstract = {OBJECTIVE: To determine the optimum biofilm formation ratio of Gardnerella vaginalis (G. vaginalis) in a mixed culture with Escherichia coli (E. coli).

METHODS: G. vaginalis ATCC14018, E. coli ATCC25922, as well as five strains of G. vaginalis were selected from the vaginal sources of patients whose biofilm forming capacity was determined by the Crystal Violet method. The biofilm forming capacity of E. coli in anaerobic and non-anaerobic environments were compared using the identical assay. The Crystal Violet method was also used to determine the biofilm forming capacity of a co-culture of G. vaginalis and E. coli in different ratios. After Live/Dead staining, biofilm thickness was measured using confocal laser scanning microscopy, and biofilm morphology was observed by scanning electron microscopy.

RESULTS: The biofilm forming capacity of E. coli under anaerobic environment was similar to that in a 5% CO2 environment. The biofilm forming capacity of G. vaginalis and E. coli was stronger at 10[6]:10[5] CFU/mL than at other ratios (P<0.05). Their thicknesses were greater at 10[6]:10[5] CFU/mL than at the other ratios, with the exception of 10[6]:10[2] CFU/mL (P<0.05), under laser scanning microscopy. Scanning electron microscopy revealed increased biofilm formation at 10[6]:10[5] CFU/mL and 10[6]:10[2] CFU/mL, but no discernible E. coli was observed at 10[6]:10[2] CFU/mL.

CONCLUSION: G. vaginalis and E. coli showed the greatest biofilm forming capacity at a concentration of 10[6]:10[5] CFU/mL at 48 hours and could be used to simulate a mixed infection of bacterial vaginosis and aerobic vaginitis in vitro.},
}

*Biofilms/growth & development
*Gardnerella vaginalis/physiology/growth & development
Humans
*Escherichia coli/physiology
Female
*Vaginosis, Bacterial/microbiology
*Microscopy, Electron, Scanning
Microscopy, Confocal
Vagina/microbiology
Anaerobiosis
Coculture Techniques
Vaginitis/microbiology

@article {pmid38751716,
year = {2024},
author = {Kaplan, JB and Cywes-Bentley, C and Pier, GB and Yakandawala, N and Sailer, M and Edwards, MS and Kridin, K},
title = {Poly-β-(1→6)-N-acetyl-D-glucosamine mediates surface attachment, biofilm formation, and biocide resistance in Cutibacterium acnes.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1386017},
pmid = {38751716},
issn = {1664-302X},
abstract = {BACKGROUND: The commensal skin bacterium Cutibacterium acnes plays a role in the pathogenesis of acne vulgaris and also causes opportunistic infections of implanted medical devices due to its ability to form biofilms on biomaterial surfaces. Poly-β-(1→6)-N-acetyl-D-glucosamine (PNAG) is an extracellular polysaccharide that mediates biofilm formation and biocide resistance in a wide range of bacterial pathogens. The objective of this study was to determine whether C. acnes produces PNAG, and whether PNAG contributes to C. acnes biofilm formation and biocide resistance in vitro.

METHODS: PNAG was detected on the surface of C. acnes cells by fluorescence confocal microscopy using the antigen-specific human IgG1 monoclonal antibody F598. PNAG was detected in C. acnes biofilms by measuring the ability of the PNAG-specific glycosidase dispersin B to inhibit biofilm formation and sensitize biofilms to biocide killing.

RESULTS: Monoclonal antibody F598 bound to the surface of C. acnes cells. Dispersin B inhibited attachment of C. acnes cells to polystyrene rods, inhibited biofilm formation by C. acnes in glass and polypropylene tubes, and sensitized C. acnes biofilms to killing by benzoyl peroxide and tetracycline.

CONCLUSION: C. acnes produces PNAG, and PNAG contributes to C. acnes biofilm formation and biocide resistance in vitro. PNAG may play a role in C. acnes skin colonization, biocide resistance, and virulence in vivo.},
}

@article {pmid38751055,
year = {2024},
author = {Cao, B and Zhang, J and Ma, Y and Wang, Y and Li, Y and Wang, R and Cao, D and Yang, Y and Zhang, R},
title = {Dual-Polymer Functionalized Melanin-AgNPs Nanocomposite with Hydroxyapatite Binding Ability to Penetrate and Retain in Biofilm Sequentially Treating Periodontitis.},
journal = {Small (Weinheim an der Bergstrasse, Germany)},
volume = {},
number = {},
pages = {e2400771},
doi = {10.1002/smll.202400771},
pmid = {38751055},
issn = {1613-6829},
support = {2023YFC3402800//National Key Research and Development Program of China/ ; 82120108016//National Natural Science Foundation of China/ ; 82071987//National Natural Science Foundation of China/ ; 202104010910010//Key Laboratory of Nano-imaging and Drug-loaded Preparation of Shanxi Province/ ; 20210302124035//Shanxi Province Science Foundation for Youths/ ; 20210302124285//Shanxi Province Science Foundation for Youths/ ; 202104010911026//Shanxi Center of Technology Innovation for Controlled and Sustained Release of Nano-drugs/ ; 2022RC14//Scientific Research Foundation of Shanxi Bethune Hospital/ ; 2023GZRZ02//National Natural Science Foundation Seed Player Project of Shanxi Bethune Hospital/ ; },
abstract = {Periodontitis is the leading cause of adult tooth missing. Thorny bacterial biofilm and high reactive oxygen species (ROS) levels in tissue are key elements for the periodontitis process. It is meaningful to develop an advanced therapeutic system with sequential antibacterial/ antioxidant ability to meet the overall goals of periodontitis therapy. Herein, a dual-polymer functionalized melanin-AgNPs (P/D-MNP-Ag) with biofilm penetration, hydroxyapatite binding, and sequentially treatment ability are fabricated. Polymer enriched with 2-(Dimethylamino)ethyl methacrylate (D), can be protonated in an acid environment with enhanced positive charge, promoting penetration in biofilm. The other polymer is rich in phosphate group (P) and can chelate Ca[2+], promoting the polymer to adhere to the hydroxyapatite surface. Melanin has good ROS scavenging and photothermal abilities, after in situ reduction Ag, melanin-AgNPs composite has sequentially transitioned between antibacterial and antioxidative ability due to heat and acid accelerated Ag[+] release. The released Ag[+] and heat have synergistic antibacterial effects for bacterial killing. With Ag[+] consumption, the antioxidant ability of MNP recovers to scavenge ROS in the inflammatory area. When applied in the periodontitis model, P/D-MNP-Ag has good therapeutical effects to ablate biofilm, relieve inflammation state, and reduce alveolar bone loss. P/D-MNP-Ag with sequential treatment ability provides a reference for developing advanced oral biofilm eradication systems.},
}

@article {pmid38750998,
year = {2024},
author = {Liu, X and Wang, D and Qi, X and Gu, Y and Huang, X and Liang, P},
title = {Propionate outperforms conventional acetate as electron donors for highly-sensitive electrochemical active biofilm sensors in water biotoxicity early-warning.},
journal = {Environmental research},
volume = {252},
number = {Pt 4},
pages = {119127},
doi = {10.1016/j.envres.2024.119127},
pmid = {38750998},
issn = {1096-0953},
abstract = {With the ability to generate in situ real-time electric signals, electrochemically active biofilm (EAB) sensors have attracted wide attention as a promising water biotoxicity early-warning device. Organic matters serving as the electron donors potentially affect the electric signal's output and the sensitivity of the EAB sensor. To explore the influence of organic matters on EAB sensor's performance, this study tested six different organic matters during the sensor's inoculation. Besides the acetate, a conventional and widely used organic matter, propionate and lactate were also found capable of starting up the sensor. Moreover, the propionate-fed (PF) sensor delivered the highest sensitivity, which are respectively 1.4 times and 2.8 times of acetate-fed (AF) sensor and lactate-fed (LF) sensor. Further analysis revealed that EAB of PF sensor had more vulnerable intracellular metabolism than the others, which manifested as the most severe energy metabolic suppression and reactive oxygen species attack. Regarding the microbial function, a two-component system that was deemed as an environment awareness system was found in the EAB of PF, which also contributed to its high sensitivity. Finally, PF sensor was tested in real water environment to deliver early-warning signals.},
}

@article {pmid38749386,
year = {2024},
author = {Aragão, MGB and He, X and Aires, CP and Corona, SAM},
title = {Epigallocatechin gallate reduces the virulence of cariogenic Streptococcus mutans biofilm by affecting the synthesis of biofilm matrix components.},
journal = {Archives of oral biology},
volume = {164},
number = {},
pages = {105990},
doi = {10.1016/j.archoralbio.2024.105990},
pmid = {38749386},
issn = {1879-1506},
abstract = {INTRODUCTION: There have been reports on the effects of epigallocatechin gallate (EGCG) against Streptococcus mutans viability and acidogenesis. However, the effects of EGCG on the virulence of S. mutans biofilm development have yet to be fully investigated using validated cariogenic biofilm models.

OBJECTIVE: Thus, this study aimed to evaluate the effects of EGCG on S. mutans biofilm virulence using a validated cariogenic model and clinically relevant treatment regimens, twice a day for 1.5 min.

METHODS: Effects of EGCG on bacterial viability, polyssacharide synthesis and biofilm acidogenesis were evaluated. The morphology and 3D structure of the biofilms were evaluated by scanning electron (SEM) and confocal laser scanning microscopy, respectively.

RESULTS: No significant change in S. mutans viability or culture medium pH were observed when comparing EGCG-treated and NaCl-treated biofilms. EGCG significantly reduced the accumulation of soluble and insoluble polysaccharides, resulting in the formation of a biofilm with interspaced exopolysaccharide-microcolony complexes unevenly distributed on enamel. The SEM images of the biofilm treated with EGCG depict multilayers of cells arranged in short chains of microorganisms adhered to an unstructured matrix, which is not continuous and does not enmesh or protect the microorganisms entirely. Importantly, confocal images demonstrated that treatment with EGCG affected the 3D structure and organization of S. mutans biofilm, which presented a biofilm matrix more confined to the location of the microcolonies.

CONCLUSION: In conclusion, EGCG lowered the virulence of S. mutans matrix-rich biofilm by reducing the synthesis of biofilm matrix components, altering the biofilm matrix structure, organization, and distribution.},
}

@article {pmid38748449,
year = {2024},
author = {Mishra, AH and Mohan, S and Gutti, P and Krishna, S and Sundaraman, S and Chakraborti, S and Jaiswal, AK and Nambi Raj, NA and Mishra, D},
title = {Bioselective and Radiopaque Zinc-Biopolymeric Complex-Based Porous Biomaterials Promote Mammalian Tissue Ingrowth In Vivo While Inhibiting Microbial Biofilm Gene Expression and Biofilm Formation.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.4c00013},
pmid = {38748449},
issn = {2576-6422},
abstract = {Metal-organic complexes have shown astounding bioactive properties; however, they are rarely explored as biomaterials. Recent studies showed that carboxymethyl-chitosan (CMC) genipin-conjugated zinc biomimetic scaffolds have unique bioselective properties. The biomaterial was reported to be mammalian cell-friendly; at the same time, it was found to discourage microbial biofilm formation on its surface, which seemed to be a promising solution to addressing the problem of trauma-associated biofilm formation and development of antimicrobial resistance. However, the mechanically frail characteristics and zinc overload raise concerns and limit the potential of the said biomaterials. Hence, the present work is focused on improving the strength of the earlier scaffold formulations, testing its in vivo efficacy and reaffirming its action against biofilm-forming microbe Staphylococcus aureus. Scaling up of CMC proportion increased rigidity, and 8% CMC was found to be the ideal concentration for robust scaffold fabrication. Freeze-dried CMC scaffolds with or without genipin (GP) cross-linking were conjugated with zinc using 2 M zinc acetate solution. Characterization results indicated that the CMC-Zn scaffolds, without genipin, showed mechanical properties close to bone fillers, resist in vitro enzymatic degradation until 4 weeks, are porous in nature, and have radiopacity close to mandibular bones. Upon implantation in a subcutaneous pocket of Wistar rats, the scaffolds showed tissue in-growth with simultaneous degradation without any signs of toxicity past 28 days. Neither were there any signs of toxicity in any of the vital organs. Considering many superior properties among the other formulations, the CMC-Zn scaffolds were furthered for biofilm studies. CMC-Zn showed negligible S. aureus biofilm formation on its surface as revealed by an alamar blue-based study. RT-PCR analysis revealed that CMC-Zn downregulated the expression of pro-biofilm effector genes such as icaC and clfB. A protein docking study predicted the inhibitory mechanism of CMC-Zn. Although it binds strongly when alone, at high density, it may cause inactivation of the transmembrane upstream activators of the said genes, thereby preventing their dimerization and subsequent inactivation of the effector genes. In conclusion, zinc-conjugated carboxymethyl-chitosan scaffolds are mechanically robust, porous, yet biodegradable, harmless to the host in the long term, they are radiopaque and prevent biofilm gene expression in notorious microbes; hence, they could be a suitable candidate for bone filler applications.},
}

@article {pmid38746970,
year = {2024},
author = {Fan, D and Xie, R and Liu, X and Li, H and Luo, Z and Li, Y and Chen, F and Zeng, W},
title = {A peptide-based pH-sensitive antibacterial hydrogel for healing drug-resistant biofilm-infected diabetic wounds.},
journal = {Journal of materials chemistry. B},
volume = {},
number = {},
pages = {},
doi = {10.1039/d4tb00594e},
pmid = {38746970},
issn = {2050-7518},
abstract = {Diabetic foot ulcers are a significant complication affecting roughly 15% of diabetic patients. These chronic wounds can be incredibly burdensome, leading to high treatment costs, potential amputations, and additional health complications. Microbiological studies reveal that bacterial infections are the primary culprit behind delayed wound healing. To solve the problem of infection at the wound site, the most fundamental thing is to kill the pathogenic bacteria. Herein, a neoteric strategy to construct novel antibacterial hydrogel COA-T3 that combined photosensitizers (PSs) and antimicrobial peptides (AMPs) via covalent coupling was proposed. Hydrogel COA-T3 composed of quaternized chitosan (QCS) and oxidized dextran (OD) was constructed for co-delivery of the photosensitizer TPI-PN and the antimicrobial peptide HHC10. In vitro and in vivo experiments demonstrated remarkable effectiveness of COA-T3 against drug-resistant bacteria. Furthermore, the hydrogel significantly promoted healing of diabetic infected wounds. This enhanced antibacterial activity is attributed to the pH-sensitive release of both PSs and AMPs within the hydrogel. Additionally, COA-T3 exhibits excellent biocompatibility, making it a promising candidate for wound dressing materials. These findings indicated that the COA-T3 hydrogel is a promising wound dressing material for promoting the healing of diabetic foot ulcers by providing an environment conducive to improved wound healing in diabetic patients.},
}

@article {pmid38746121,
year = {2024},
author = {García-Bayona, L and Said, N and Coyne, MJ and Flores, K and Elmekki, NM and Sheahan, ML and Camacho, AG and Hutt, K and Yildiz, FH and Kovács, ÁT and Waldor, MK and Comstock, LE},
title = {A pervasive large conjugative plasmid mediates multispecies biofilm formation in the intestinal microbiota increasing resilience to perturbations.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.04.29.590671},
pmid = {38746121},
abstract = {Although horizontal gene transfer is pervasive in the intestinal microbiota, we understand only superficially the roles of most exchanged genes and how the mobile repertoire affects community dynamics. Similarly, little is known about the mechanisms underlying the ability of a community to recover after a perturbation. Here, we identified and functionally characterized a large conjugative plasmid that is one of the most frequently transferred elements among Bacteroidales species and is ubiquitous in diverse human populations. This plasmid encodes both an extracellular polysaccharide and fimbriae, which promote the formation of multispecies biofilms in the mammalian gut. We use a hybridization-based approach to visualize biofilms in clarified whole colon tissue with unprecedented 3D spatial resolution. These biofilms increase bacterial survival to common stressors encountered in the gut, increasing strain resiliency, and providing a rationale for the plasmid's recent spread and high worldwide prevalence.},
}

@article {pmid38745848,
year = {2024},
author = {Pokhrel, S and Sharma, N and Aryal, S and Khadka, R and Thapa, TB and Pandey, P and Joshi, G},
title = {Detection of Biofilm Production and Antibiotic Susceptibility Pattern among Clinically Isolated Staphylococcus aureus.},
journal = {Journal of pathogens},
volume = {2024},
number = {},
pages = {2342468},
pmid = {38745848},
issn = {2090-3057},
abstract = {AIM: The increasing antibiotic resistance and the ability to form biofilms in medical devices have become the leading cause of severe infections associated with Staphylococcus aureus (S. aureus). Since the bacteria living in biofilms can exhibit 10- to 1,000-fold increase in antibiotic resistance and implicate chronic infectious diseases, the detection of S. aureus ability to form biofilms is of great importance for managing, minimizing, and effectively treating infections caused by it. This study aimed to compare the tube and tissue culture methods to detect biofilm production and antibiotic susceptibility in MRSA and MSSA.

MATERIALS AND METHODS: The S. aureus isolates were identified by the examination of the colony morphology, Gram staining, and various biochemical tests. Antimicrobial susceptibility testing of all isolates was performed by the modified Kirby-Bauer disc diffusion method as recommended by CLSI guidelines. MRSA screening was performed phenotypically using a cefoxitin disc (30 µg). Isolates were tested for inducible resistance using the D-test, and two phenotypic methods detected biofilm formation.

RESULTS: Among 982 nonrepeated clinical specimens, S. aureus was isolated from 103 (10.48%). Among 103 clinical isolates of S. aureus, 54 (52.42%) isolates were MRSA, and 49 (47.57%) were MSSA. Among 54 MRSA isolates, the inducible MLSB phenotype was observed in 23/54 (42.59%) with a positive D-test. By TCP method, 26 (48.1%) MRSA isolates were strong biofilm producers, whereas, among all MSSA isolates, only 6 (12.2%) were strong biofilm producers.

CONCLUSION: MRSA showed strong biofilm production in comparison with MSSA. The TCP method is a recommended reliable method to detect the biofilm among S. aureus isolates, and the TM method could be useful for the screening of biofilm production in S. aureus in the routine clinical laboratory.},
}

@article {pmid38744766,
year = {2024},
author = {Er-Rahmani, S and Errabiti, B and Matencio, A and Trotta, F and Latrache, H and Koraichi, SI and Elabed, S},
title = {Plant-derived bioactive compounds for the inhibition of biofilm formation: a comprehensive review.},
journal = {Environmental science and pollution research international},
volume = {},
number = {},
pages = {},
pmid = {38744766},
issn = {1614-7499},
abstract = {Biofilm formation is a widespread phenomenon that impacts different fields, including the food industry, agriculture, health care and the environment. Accordingly, there is a serious need for new methods of managing the problem of biofilm formation. Natural products have historically been a rich source of varied compounds with a wide variety of biological functions, including antibiofilm agents. In this review, we critically highlight and discuss the recent progress in understanding the antibiofilm effects of several bioactive compounds isolated from different plants, and in elucidating the underlying mechanisms of action and the factors influencing their adhesion. The literature shows that bioactive compounds have promising antibiofilm potential against both Gram-negative and Gram-positive bacterial and fungal strains, via several mechanisms of action, such as suppressing the formation of the polymer matrix, limiting O2 consumption, inhibiting microbial DNA replication, decreasing hydrophobicity of cell surfaces and blocking the quorum sensing network. This antibiofilm activity is influenced by several environmental factors, such as nutritional cues, pH values, O2 availability and temperature. This review demonstrates that several bioactive compounds could mitigate the problem of biofilm production. However, toxicological assessment and pharmacokinetic investigations of these molecules are strongly required to validate their safety.},
}

@article {pmid38744691,
year = {2024},
author = {Pradhan, L and Sah, P and Nayak, M and Upadhyay, A and Pragya, P and Tripathi, S and Singh, G and Mounika, B and Paik, P and Mukherjee, S},
title = {Biosynthesized silver nanoparticles prevent bacterial infection in chicken egg model and mitigate biofilm formation on medical catheters.},
journal = {Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry},
volume = {},
number = {},
pages = {},
pmid = {38744691},
issn = {1432-1327},
support = {R22-2922732087//Royal Society of Chemistry/ ; },
abstract = {Investigating the application of innovative antimicrobial surface coatings on medical devices is an important field of research. Many of these coatings have significant drawbacks, including biocompatibility, coating stability and the inability to effectively combat multiple drug-resistant bacteria. In this research, we developed an antibiofilm surface coating for medical catheters using biosynthesized silver nanoparticles (b-Cs-AgNPs) developed using leaves extract of Calliandra surinamensis. Various characterization techniques were employed to thoroughly characterize the synthesized b-Cs-AgNPs and c-AgNPs. b-Cs-AgNPs were compatible with human normal kidney cells and chicken embryos. It did not trigger any skin inflammatory response in in vivo rat model. b-Cs-AgNPs demonstrated potent zone of inhibition of 19.09 mm when subjected to the disc diffusion method in E. coli confirming strong antibacterial property. Different anti-bacterial assays including liquid growth curve, colony counting assay, biofilm formation assay supported the potent antimicrobial efficacy of b-Cs-AgNPs alone and when coated to medical grade catheters. Mechanistic studies reveal the presence of ferulic acid, that was important for the synthesis of b-AgNPs along with enhanced antibacterial effects of b-Cs-AgNPs compared to c-AgNPs, supported by molecular docking analysis. These results together demonstrated the effective role b-Cs-AgNPs in combating infections and mitigating biofilm formations, highlighting their need for further study in the field of biomedical applications.},
}

@article {pmid38744329,
year = {2024},
author = {Kriswandini, IL and Sidarningsih, S and Hermanto, AC and Tyas, PR and Aljunaid, MA},
title = {The Influence of Streptococcus mutans Biofilm Formation in a Polymicrobial Environment (Streptococcus gordonii & Porphyromonas gingivalis).},
journal = {European journal of dentistry},
volume = {},
number = {},
pages = {},
doi = {10.1055/s-0044-1782215},
pmid = {38744329},
issn = {1305-7456},
abstract = {OBJECTIVES: Biofilms play a vital role in the occurrence or worsening of an infectious disease. Streptococcus mutans is a bacterium with the ability to form biofilms that plays a key role in the development of infectious diseases such as dental caries. The formation of biofilms in S. mutans is mediated by quorum sensing. Inhibiting quorum sensing can be considered as one of the approaches to prevent caries. This study aims to investigate the ability of Streptococcus gordonii and Porphyromonas gingivalis bacteria to inhibit the formation of S. mutans biofilm.

MATERIALS AND METHODS:  This research was conducted to analyze bacterial biofilm formation and metabolism. The bacteria used are S. mutans (serotype C), S. gordonii (ATCC 5165), and P. gingivalis (ATCC 33277). Biofilm formation was analyzed using the crystal violet assay. Bacterial metabolism was analyzed using the methylthiazol tetrazolium (MTT) assay.

RESULTS:  The results of the crystal violet assay indicate a decrease in biofilm formation in S. mutans when in the presence of S. gordonii and S. mutans in the presence of P. gingivalis. The results of the MTT assay show no significant change in the bacterial metabolism of S. mutans in the presence of S. gordonii and S. mutans in the presence of P. gingivalis. However, S. mutans with the presence of S. gordonii and P. gingivalis show an increase in biofilm formation and bacterial metabolism.

CONCLUSION:  S. gordonii and P. gingivalis are each capable of inhibiting the formation of S. mutans biofilm in a polymicrobial environment.},
}

@article {pmid38744202,
year = {2024},
author = {Cheng, Y and Ding, J and Wan, J and Tang, L and Joseph, A and Usman, M and Zhu, N and Zhang, Y and Sun, H and Rene, ER and Lendvay, M and Li, Y},
title = {Improvement of biotic nitrate reduction in constructed photoautotrophic biofilm-soil microbial fuel cells.},
journal = {Journal of environmental management},
volume = {360},
number = {},
pages = {121066},
doi = {10.1016/j.jenvman.2024.121066},
pmid = {38744202},
issn = {1095-8630},
abstract = {The biotic nitrate reduction rate in freshwater ecosystems is typically constrained by the scarcity of carbon sources. In this study, 'two-chambers' - 'two-electrodes' photoautotrophic biofilm-soil microbial fuel cells (P-SMFC) was developed to accelerate nitrate reduction by activating in situ electron donors that originated from the soil organic carbon (SOC). The nitrate reduction rate of P-SMFC (0.1341 d[-1]) improved by ∼ 1.6 times on the 28th day compared to the control photoautotrophic biofilm. The relative abundance of electroactive bacterium increased in the P-SMFC and this bacterium contributed to obtain electrons from SOC. Biochar amendment decreased the resistivity of P-SMFC, increased the electron transferring efficiency, and mitigated anodic acidification, which continuously facilitated the thriving of putative electroactive bacterium and promoted current generation. The results from physiological and ecological tests revealed that the cathodic photoautotrophic biofilm produced more extracellular protein, increased the relative abundance of Lachnospiraceae, Magnetospirillaceae, Pseudomonadaceae, and Sphingomonadaceae, and improved the activity of nitrate reductase and ATPase. Correspondingly, P-SMFC in the presence of biochar achieved the highest reaction rate constant for nitrate reduction (kobs) (0.2092 d[-1]) which was 2.4 times higher than the control photoautotrophic biofilm. This study provided a new strategy to vitalize in situ carbon sources in paddy soil for nitrate reduction by the construction of P-SMFC.},
}

@article {pmid38744081,
year = {2024},
author = {Müller, N and Kollert, M and Trampuz, A and Gonzalez Moreno, M},
title = {Efficacy of different bioactive glass S53P4 formulations in biofilm eradication and the impact of pH and osmotic pressure.},
journal = {Colloids and surfaces. B, Biointerfaces},
volume = {239},
number = {},
pages = {113940},
doi = {10.1016/j.colsurfb.2024.113940},
pmid = {38744081},
issn = {1873-4367},
abstract = {AIM: The challenging properties of biofilm-associated infections and the rise of multidrug-resistant bacteria are prompting the exploration of alternative treatment options. This study investigates the efficacy of different bioactive glass (BAG) formulations - alone or combined with vancomycin - to eradicate biofilm. Further, we study the influence of BAG on pH and osmotic pressure as important factors limiting bacterial growth.

METHOD: Different BAG S53P4 formulations were used for this study, including (a) powder (<45 μm), (b) granules (500-800 µm), (c) a cone-shaped scaffold and (d) two putty formulations containing granules with no powder (putty A) or with additional powder (putty B) bound together by a synthetic binder. Inert glass beads (1.0-1.3 mm) were included as control. All formulations were tested in a concentration of 1750 mg/ml in Müller-Hinton-Broth against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE). Vancomycin was tested at the minimum-inhibitory concentration for each strain. Changes in pH and osmolality over time were assessed at 0 h, 24 h, 72 h and 168 h.

RESULTS: All tested BAG formulations showed antibiofilm activity against MRSA and MRSE. Powder and putty B were the most effective formulations suppressing biofilm leading to its complete eradication after up to 168 h of co-incubation, followed by granules, scaffold and putty A. In general, MRSE appeared to be more susceptible to bioactive glass compared to MRSA. The addition of vancomycin had no substantial impact on biofilm eradication. We observed a positive correlation between a higher pH and higher antibiofilm activity.

CONCLUSIONS: BAG S53P4 has demonstrated efficient biofilm antibiofilm activity against MRSA and MRSE, especially in powder-containing formulations, resulting in complete eradication of biofilm. Our data indicate neither remarkable increase nor decrease in antimicrobial efficacy with addition of vancomycin. Moreover, high pH appears to have a direct antimicrobial impact; the role of high osmolality needs further investigation.},
}

@article {pmid38744077,
year = {2024},
author = {Qu, L and Li, X and Zhou, J and Peng, X and Zhou, P and Zheng, H and Jiang, Z and Xie, Q},
title = {A novel acid-responsive polymer coating with antibacterial and antifouling properties for the prevention of biofilm-associated infections.},
journal = {Colloids and surfaces. B, Biointerfaces},
volume = {239},
number = {},
pages = {113939},
doi = {10.1016/j.colsurfb.2024.113939},
pmid = {38744077},
issn = {1873-4367},
abstract = {Chronic infections caused by the pathogenic biofilms on implantable medical devices pose an increasing challenge. To combat long-term biofilm-associated infections, we developed a novel dual-functional polymer coating with antibacterial and antifouling properties. The coating consists of N-vinylpyrrolidone (NVP) and 3-(acrylamido)phenylboronic acid (APBA) copolymer brushes, which bind to curcumin (Cur) as antibacterial molecules through acid-responsive boronate ester bonds. In this surface design, the hydrophilic poly (N-vinylpyrrolidone) (PVP) component improved antifouling performance and effectively prevented bacterial adhesion and aggregation during the initial phases. The poly (3-(acrylamido) phenylboronic acid) (PAPBA, abbreviated PB) component provided binding sites for Cur by forming acid-responsive boronate ester bonds. When fewer bacteria overcame the anti-adhesion barrier and colonized, the surface responded to the decreased microenvironmental pH by breaking the boronate ester bonds and releasing curcumin. This responsive mechanism enabled Cur to interfere with biofilm formation and provide a multilayer anti-biofilm protection system. The coating showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, preventing biofilm formation for up to 7 days. The coating also inhibited protein adsorption and platelet adhesion significantly. This coating also exhibited high biocompatibility with animal erythrocytes and pre-osteoblasts. This research offers a promising approach for developing novel smart anti-biofilm coating materials.},
}

@article {pmid38743334,
year = {2024},
author = {A, D and Zhang, Y and Huang, H and Pan, Y and Di, HJ and Yi, Y and Zhang, X and Yang, J},
title = {Unraveling the mechanism of interaction: accelerated phenanthrene degradation and rhizosphere biofilm/iron plaque formation influenced by phenolic root exudates.},
journal = {Environmental science and pollution research international},
volume = {},
number = {},
pages = {},
pmid = {38743334},
issn = {1614-7499},
support = {2020B0202080002//Key Research and Development Project of Guangdong Province/ ; 2022A1515011319//Natural Science Foundation of Guangdong Province, China/ ; 202201011783//Technology Project of Guangzhou City, China/ ; 202208440274//Local Cooperation Project of China Scholarship Council/ ; },
abstract = {Phenolic root exudates (PREs) secreted by wetland plants facilitate the accumulation of iron in the rhizosphere, potentially providing the essential active iron required for the generation of enzymes that degrade polycyclic aromatic hydrocarbon, thereby enhancing their biodegradation. However, the underlying mechanisms involved are yet to be elucidated. This study focuses on phenanthrene (PHE), a typical polycyclic aromatic hydrocarbon pollutant, utilizing representative PREs from wetland plants, including p-hydroxybenzoic, p-coumaric, caffeic, and ferulic acids. Using hydroponic experiments, 16S rRNA sequencing, and multiple characterization techniques, we aimed to elucidate the interaction mechanism between the accelerated degradation of PHE and the formation of rhizosphere biofilm/iron plaque influenced by PREs. Although all four types of PREs altered the biofilm composition and promoted the formation of iron plaque on the root surface, only caffeic acid, possessing a similar structure to the intermediate metabolite of PHE (catechol), could accelerate the PHE degradation rate. Caffeic acid, notable for its catechol structure, plays a significant role in enhancing PHE degradation through two main mechanisms: (a) it directly boosts PHE co-metabolism by fostering the growth of PHE-degrading bacteria, specifically Burkholderiaceae, and by facilitating the production of the key metabolic enzyme catechol 1,2-dioxygenase (C12O) and (b) it indirectly supports PHE biodegradation by promoting iron plaque formation on root surfaces, thereby enriching free iron for efficient microbial synthesis of C12O, a crucial factor in PHE decomposition.},
}

@article {pmid38743043,
year = {2024},
author = {Lopes, N and Pereira, RB and Correia, A and Vilanova, M and Cerca, N and França, A},
title = {Deletion of codY impairs Staphylococcus epidermidis biofilm formation, generation of viable but non-culturable cells and stimulates cytokine production in human macrophages.},
journal = {Journal of medical microbiology},
volume = {73},
number = {5},
pages = {},
doi = {10.1099/jmm.0.001837},
pmid = {38743043},
issn = {1473-5644},
mesh = {*Staphylococcus epidermidis/genetics/physiology ; *Biofilms/growth & development ; Humans ; *Macrophages/microbiology/immunology ; *Cytokines/metabolism/genetics ; *Bacterial Proteins/genetics/metabolism ; Anti-Bacterial Agents/pharmacology ; Staphylococcal Infections/microbiology ; Gene Deletion ; Virulence ; Microbial Viability ; },
abstract = {Introduction. Staphylococcus epidermidis biofilms are one of the major causes of bloodstream infections related to the use of medical devices. The diagnosis of these infections is challenging, delaying their treatment and resulting in increased morbidity and mortality rates. As such, it is urgent to characterize the mechanisms employed by this bacterium to endure antibiotic treatments and the response of the host immune system, to develop more effective therapeutic strategies. In several bacterial species, the gene codY was shown to encode a protein that regulates the expression of genes involved in biofilm formation and immune evasion. Additionally, in a previous study, our group generated evidence indicating that codY is involved in the emergence of viable but non-culturable (VBNC) cells in S. epidermidis.Gap statement/Hypothesis. As such, we hypothesized that the gene codY has have an important role in this bacterium virulence.Aim. This study aimed to assess, for the first time, the impact of the deletion of the gene codY in S. epidermidis virulence, namely, in antibiotic susceptibility, biofilm formation, VBNC state emergence and in vitro host immune system response.Methodology. Using an allelic replacement strategy, we constructed and then characterized an S. epidermidis strain lacking codY, in regards to biofilm and VBNC cell formation, susceptibility to antibiotics as well as their role in the interaction with human blood and plasma. Additionally, we investigate whether the codY gene can impact the activation of innate immune cells by evaluating the production of both pro- and anti-inflammatory cytokines by THP-1 macrophages.Results. We demonstrated that the deletion of the gene codY resulted in biofilms with less c.f.u. counts and fewer VBNC cells. Furthermore, we show that although WT and mutant cells were similarly internalized in vitro by human macrophages, a stronger cytokine response was elicited by the mutant in a toll-like receptor 4-dependent manner.Conclusion. Our results indicate that codY contributes to S. epidermidis virulence, which in turn may have an impact on our ability to manage the biofilm-associated infections caused by this bacterium.},
}

*Staphylococcus epidermidis/genetics/physiology
*Biofilms/growth & development
Humans
*Macrophages/microbiology/immunology
*Cytokines/metabolism/genetics
*Bacterial Proteins/genetics/metabolism
Anti-Bacterial Agents/pharmacology
Staphylococcal Infections/microbiology
Gene Deletion
Virulence
Microbial Viability

@article {pmid38741276,
year = {2024},
author = {Ni, L and Shen, R and Luo, H and Li, X and Zhang, X and Huang, L and Deng, Y and Liao, X and Wu, Y and Duan, C and Xie, X},
title = {GlmS plays a key role in the virulence factor expression and biofilm formation ability of Staphylococcus aureus promoted by advanced glycation end products.},
journal = {Virulence},
volume = {15},
number = {1},
pages = {2352476},
doi = {10.1080/21505594.2024.2352476},
pmid = {38741276},
issn = {2150-5608},
mesh = {*Biofilms/growth & development ; *Staphylococcus aureus/genetics/pathogenicity ; *Virulence Factors/genetics ; *Glycation End Products, Advanced/metabolism ; *Bacterial Proteins/genetics/metabolism ; *Gene Expression Regulation, Bacterial ; *Staphylococcal Infections/microbiology ; Sigma Factor/genetics/metabolism ; Humans ; },
abstract = {Staphylococcus aureus (S. aureus) is well known for its biofilm formation ability and is responsible for serious, chronic refractory infections worldwide. We previously demonstrated that advanced glycation end products (AGEs), a hallmark of chronic hyperglycaemia in diabetic tissues, enhanced biofilm formation by promoting eDNA release via sigB upregulation in S. aureus, contributing to the high morbidity and mortality of patients presenting a diabetic foot ulcer infection. However, the exact regulatory network has not been completely described. Here, we used pull-down assay and LC-MS/MS to identify the GlmS as a candidate regulator of sigB in S. aureus stimulated by AGEs. Dual-luciferase assays and electrophoretic mobility shift assays (EMSAs) revealed that GlmS directly upregulated the transcriptional activity of sigB. We constructed NCTC 8325 ∆glmS for further validation. qRT-PCR analysis revealed that AGEs promoted both glmS and sigB expression in the NCTC 8325 strain but had no effect on NCTC 8325 ∆glmS. NCTC 8325 ∆glmS showed a significant attenuation in biofilm formation and virulence factor expression, accompanied by a decrease in sigB expression, even under AGE stimulation. All of the changes, including pigment deficiency, decreased haemolysis ability, downregulation of hla and hld expression, and less and sparser biofilms, indicated that sigB and biofilm formation ability no longer responded to AGEs in NCTC 8325 ∆glmS. Our data extend the understanding of GlmS in the global regulatory network of S. aureus and demonstrate a new mechanism by which AGEs can upregulate GlmS, which directly regulates sigB and plays a significant role in mediating biofilm formation and virulence factor expression.},
}

*Biofilms/growth & development
*Staphylococcus aureus/genetics/pathogenicity
*Virulence Factors/genetics
*Glycation End Products, Advanced/metabolism
*Bacterial Proteins/genetics/metabolism
*Gene Expression Regulation, Bacterial
*Staphylococcal Infections/microbiology
Sigma Factor/genetics/metabolism
Humans

@article {pmid38741081,
year = {2024},
author = {Haude, S and Matthes, R and Pitchika, V and Holtfreter, B and Schlüter, R and Gerling, T and Kocher, T and Jablonowski, L},
title = {In-vitro biofilm removal from TiUnite® implant surface with an air polishing and two different plasma devices.},
journal = {BMC oral health},
volume = {24},
number = {1},
pages = {558},
pmid = {38741081},
issn = {1472-6831},
mesh = {*Biofilms/drug effects ; *Titanium/chemistry ; *Plasma Gases ; *Surface Properties ; *Dental Implants/microbiology ; Dental Polishing/methods ; Glycine ; Humans ; In Vitro Techniques ; Microscopy, Electron, Scanning ; Nickel ; },
abstract = {BACKGROUND: We investigated the efficacy of two different cold atmospheric pressure jet plasma devices (CAP09 and CAPmed) and an air polishing device with glycine powder (AP) either applied as monotherapies or combined therapies (AP + CAP09; AP + CAPmed), in microbial biofilm removal from discs with anodised titanium surface.

METHODS: Discs covered with 7-day-old microbial biofilm were treated either with CAP09, CAPmed, AP, AP + CAP09 or AP + CAPmed and compared with negative and positive controls. Biofilm removal was assessed with flourescence and electron microscopy immediately after treatment and after 5 days of reincubation of the treated discs.

RESULTS: Treatment with CAP09 or CAPmed did not lead to an effective biofilm removal, whereas treatment with AP detached the complete biofilm, which however regrew to baseline magnitude after 5 days of reincubation. Both combination therapies (AP + CAP09 and AP + CAPmed) achieved a complete biofilm removal immediately after cleaning. However, biofilm regrew after 5 days on 50% of the discs treated with the combination therapy.

CONCLUSION: AP treatment alone can remove gross biofilm immediately from anodised titanium surfaces. However, it did not impede regrowth after 5 days, because microorganisms were probably hidden in holes and troughs, from which they could regrow, and which were inaccessible to AP. The combination of AP and plasma treatment probably removed or inactivated microorganisms also from these hard to access spots. These results were independent of the choice of plasma device.},
}

*Biofilms/drug effects
*Titanium/chemistry
*Plasma Gases
*Surface Properties
*Dental Implants/microbiology
Dental Polishing/methods
Glycine
Humans
In Vitro Techniques
Microscopy, Electron, Scanning
Nickel

@article {pmid38740670,
year = {2024},
author = {Ribeiro, NS and da Rosa, DF and Xavier, MA and Dos Reis, SV and Beys-da-Silva, WO and Santi, L and Bizarro, CV and Dalberto, PF and Basso, LA and Macedo, AJ},
title = {Unveiling antibiofilm potential: proteins from Priestia sp. targeting Staphylococcus aureus biofilm formation.},
journal = {Antonie van Leeuwenhoek},
volume = {117},
number = {1},
pages = {78},
pmid = {38740670},
issn = {1572-9699},
mesh = {*Biofilms/drug effects/growth & development ; *Staphylococcus aureus/drug effects/physiology ; *Bacterial Proteins/genetics/metabolism ; *Anti-Bacterial Agents/pharmacology ; Animals ; Microbial Sensitivity Tests ; Brazil ; Porifera/microbiology ; },
abstract = {Staphylococcus aureus is the etiologic agent of many nosocomial infections, and its biofilm is frequently isolated from medical devices. Moreover, the dissemination of multidrug-resistant (MDR) strains from this pathogen, such as methicillin-resistant S. aureus (MRSA) strains, is a worldwide public health issue. The inhibition of biofilm formation can be used as a strategy to weaken bacterial resistance. Taking that into account, we analysed the ability of marine sponge-associated bacteria to produce antibiofilm molecules, and we found that marine Priestia sp., isolated from marine sponge Scopalina sp. collected on the Brazilian coast, secretes proteins that impair biofilm development from S. aureus. Partially purified proteins (PPP) secreted after 24 hours of bacterial growth promoted a 92% biofilm mass reduction and 4.0 µg/dL was the minimum concentration to significantly inhibit biofilm formation. This reduction was visually confirmed by light microscopy and Scanning Electron Microscopy (SEM). Furthermore, biochemical assays showed that the antibiofilm activity of PPP was reduced by ethylenediaminetetraacetic acid (EDTA) and 1,10 phenanthroline (PHEN), while it was stimulated by zinc ions, suggesting an active metallopeptidase in PPP. This result agrees with mass spectrometry (MS) identification, which indicated the presence of a metallopeptidase from the M28 family. Additionally, whole-genome sequencing analysis of Priestia sp. shows that gene ywad, a metallopeptidase-encoding gene, was present. Therefore, the results presented herein indicate that PPP secreted by the marine Priestia sp. can be explored as a potential antibiofilm agent and help to treat chronic infections.},
}

*Biofilms/drug effects/growth & development
*Staphylococcus aureus/drug effects/physiology
*Bacterial Proteins/genetics/metabolism
*Anti-Bacterial Agents/pharmacology
Animals
Microbial Sensitivity Tests
Brazil
Porifera/microbiology

@article {pmid38740038,
year = {2024},
author = {Xu, Y and Luo, W and Deng, H and Hu, X and Zhang, J and Wang, Y},
title = {Robust antibacterial activity of rare-earth ions on planktonic and biofilm bacteria.},
journal = {Biomedical materials (Bristol, England)},
volume = {},
number = {},
pages = {},
doi = {10.1088/1748-605X/ad4aa9},
pmid = {38740038},
issn = {1748-605X},
abstract = {Bacterial infections pose a serious threat to human health, with emerging antibiotic resistance, necessitating the development of new antibacterial agents. Cu[2+]and Ag[+]are widely recognized antibacterial agents with a low propensity for inducing bacterial resistance; however, their considerable cytotoxicity constrains their clinical applications. Rare-earth ions, owing to their unique electronic layer structure, hold promise as promising alternatives. However, their antibacterial efficacy and biocompatibility relative to conventional antibacterial agents remain underexplored, and the variations in activity across different rare-earth ions remain unclear. Here, we systematically evaluate the antibacterial activity of five rare-earth ions (Yb[3+], Gd[3+], Sm[3+], Tb[3+], and La[3+]) againstStaphylococcus aureusandPseudomonas aeruginosa, benchmarked against well-established antibacterial agents (Cu[2+], Ag[+]) and the antibiotic norfloxacin. Cytotoxicity is also assessed via live/dead staining of fibroblasts after 24 h rare-earth ion exposure. Our findings reveal that rare-earth ions require higher concentrations to match the antibacterial effects of traditional agents but offer the advantage of significantly lower cytotoxicity. In particular, Gd[3+]demonstrates potent bactericidal efficacy against both planktonic and biofilm bacteria, while maintaining the lowest cytotoxicity toward mammalian cells. Moreover, the tested rare-earth ions also exhibited excellent antifungal activity againstCandida albicans. This study provides a critical empirical framework to guide the selection of rare-earth ions for biomedical applications, offering a strategic direction for the development of novel antimicrobial agents.},
}

@article {pmid38739655,
year = {2024},
author = {Xiong, L and Pereira De Sa, N and Zarnowski, R and Huang, MY and Mota Fernandes, C and Lanni, F and Andes, DR and Del Poeta, M and Mitchell, AP},
title = {Biofilm-associated metabolism via ERG251 in Candida albicans.},
journal = {PLoS pathogens},
volume = {20},
number = {5},
pages = {e1012225},
doi = {10.1371/journal.ppat.1012225},
pmid = {38739655},
issn = {1553-7374},
abstract = {Biofilm formation by the fungal pathogen Candida albicans is the basis for its ability to infect medical devices. The metabolic gene ERG251 has been identified as a target of biofilm transcriptional regulator Efg1, and here we report that ERG251 is required for biofilm formation but not conventional free-living planktonic growth. An erg251Δ/Δ mutation impairs biofilm formation in vitro and in an in vivo catheter infection model. In both in vitro and in vivo biofilm contexts, cell number is reduced and hyphal length is limited. To determine whether the mutant defect is in growth or some other aspect of biofilm development, we examined planktonic cell features in a biofilm-like environment, which was approximated with sealed unshaken cultures. Under those conditions, the erg251Δ/Δ mutation causes defects in growth and hyphal extension. Overexpression in the erg251Δ/Δ mutant of the paralog ERG25, which is normally expressed more weakly than ERG251, partially improves biofilm formation and biofilm hyphal content, as well as growth and hyphal extension in a biofilm-like environment. GC-MS analysis shows that the erg251Δ/Δ mutation causes a defect in ergosterol accumulation when cells are cultivated under biofilm-like conditions, but not under conventional planktonic conditions. Overexpression of ERG25 in the erg251Δ/Δ mutant causes some increase in ergosterol levels. Finally, the hypersensitivity of efg1Δ/Δ mutants to the ergosterol inhibitor fluconazole is reversed by ERG251 overexpression, arguing that reduced ERG251 expression contributes to this efg1Δ/Δ phenotype. Our results indicate that ERG251 is required for biofilm formation because its high expression levels are necessary for ergosterol synthesis in a biofilm-like environment.},
}

@article {pmid38739212,
year = {2024},
author = {Datta, S and Singh, V and Nag, S and Roy, DN},
title = {Marine-Derived Cytosine Arabinoside (Ara-C) Inhibits Biofilm Formation by Inhibiting PEL Operon Proteins (Pel A and Pel B) of Pseudomonas aeruginosa: An In Silico Approach.},
journal = {Molecular biotechnology},
volume = {},
number = {},
pages = {},
pmid = {38739212},
issn = {1559-0305},
abstract = {Pseudomonas aeruginosa (P. aeruginosa) is a gram-negative biofilm-forming opportunistic human pathogen whose vital mechanism is biofilm formation for better survival. PelA and PelB proteins of the PEL operon are essential for bacterial-synthesized pellicle polysaccharide (PEL), which is a vital structural component of the biofilm. It helps in adherence of biofilm on the surface and maintenance of cell-to-cell interactions and with other matrix components. Here, in-silico molecular docking and simulation studies were performed against PelA and PelB using ten natural bioactive compounds, individually [podocarpic acids, ferruginol, scopadulcic acid B, pisiferic acid, metachromin A, Cytarabine (cytosine arabinoside; Ara-C), ursolic acid, oleanolic acid, maslinic acid, and betulinic acid], those have already been established as anti-infectious compounds. The results obtained from AutoDock and Glide-Schordinger stated that a marine-derived cytosine arabinoside (Ara-C) among the ten compounds binds active sites of PelA and PelB, exhibiting strong binding affinity [Trp224 (hydrogen), Ser219 (polar), Val234 (hydrophobic) for PelA; Leu365 and Glu389 (hydrogen), Gln366 (polar) for PelB] with high negative binding energy - 5.518 kcal/mol and - 6.056 kcal/mol, respectively. The molecular dynamic and simulation studies for 100 ns showed the MMGBSA binding energy scores are - 16.4 kcal/mol (Ara-C with PelA), and - 22.25 kcal/mol (Ara-C with PelB). Further, ADME/T studies indicate the IC50 values of AraC are 6.10 mM for PelA and 18.78 mM for PelB, which is a comparatively very low dose. The zero violation of Lipinski's Rule of Five further established that Ara-C is a good candidate for drug development. Thus, Ara-C could be considered a potent anti-biofilm compound against PEL operon-dependent biofilm formation of P. aeruginosa.},
}

@article {pmid38738757,
year = {2024},
author = {Quni, S and Zhang, Y and Liu, L and Liu, M and Zhang, L and You, J and Cui, J and Liu, X and Wang, H and Li, D and Zhou, Y},
title = {NF-κB-Signaling-Targeted Immunomodulatory Nanoparticle with Photothermal and Quorum-Sensing Inhibition Effects for Efficient Healing of Biofilm-Infected Wounds.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.4c03142},
pmid = {38738757},
issn = {1944-8252},
abstract = {The development of therapeutics with high antimicrobial activity and immunomodulatory effects is urgently needed for the treatment of infected wounds due to the increasing danger posed by recalcitrant-infected wounds. In this study, we developed light-controlled antibacterial, photothermal, and immunomodulatory biomimetic N/hPDA@M nanoparticles (NPs). This nanoplatform was developed by loading flavonoid naringenin onto hollow mesoporous polydopamine NPs in a π-π-stacked configuration and encasing them with macrophage membranes. First, our N/hPDA@M NPs efficiently neutralized inflammatory factors present within the wound microenvironment by the integration of macrophage membranes. Afterward, the N/hPDA@M NPs effectively dismantled bacterial biofilms through a combination of the photothermal properties of PDA and the quorum sensing inhibitory effects of naringenin. It is worth noting that N/hPDA@M NPs near-infrared-enhanced release of naringenin exhibited specificity toward the NF-κB-signaling pathway, effectively mitigating the inflammatory response. This innovative design not only conferred remarkable antibacterial properties upon the N/hPDA@M NPs but also endowed them with the capacity to modulate inflammatory responses, curbing excessive inflammation and steering macrophage polarization toward the M2 phenotype. As a result, this multifaceted approach significantly contributes to expediting the healing process of infected skin wounds.},
}

@article {pmid38737754,
year = {2024},
author = {Tang, Y and Zhang, Z and Tao, C and Wang, X},
title = {The mechanism of biofilm detachment in porous medium under flow field.},
journal = {Biomicrofluidics},
volume = {18},
number = {3},
pages = {034103},
pmid = {38737754},
issn = {1932-1058},
abstract = {Biofilms are communities formed by bacteria adhering to surfaces, widely present in porous medium, and their growth can lead to clogging. Our experiment finds that under certain flow conditions, biofilms detach in pores and form a dynamically changing flow path. We define detachment that occurs far from the boundary of the flow path (with a distance greater than 200 μm) as internal detachment and detachment that occurs at the boundary of the flow path as external detachment. To understand the mechanism of biofilm detachment, we study the detachment behaviors of the Bacillus subtilis biofilm in a porous medium in a microfluidic device, where Bacillus subtilis strain is triple fluorescent labeled, which can represent three main phenotypes during the biofilm formation: motile cells, matrix-producing cells, and spores. We find that slow small-scale internal detachment occurs in regions with very few motile cells and matrix-producing cells, and bacterial movement in these areas is disordered. The increase in the number of matrix-producing cells induces clogging, and after clogging, the rapid detachment of the bulk internal biofilm occurs due to the increased pressure difference at the inlet and outlet. When both internal and external detachments occur simultaneously, the number of matrix-producing cells in the internal detachment area is 2.5 times that in the external detachment area. The results indicate that biofilm detachment occurs in areas with fewer matrix-producing cells, as matrix-producing cells can help resist detachment by secreting extracellular polymeric substances (EPSs).},
}

@article {pmid38736937,
year = {2024},
author = {Bakalakos, M and Ampadiotaki, MM and Vlachos, C and Sipsas, N and Pneumaticos, S and Vlamis, J},
title = {Molecular Mechanisms of Biofilm Formation on Orthopaedic Implants: Review of the Literature.},
journal = {Maedica},
volume = {19},
number = {1},
pages = {129-136},
pmid = {38736937},
issn = {1841-9038},
abstract = {Orthopaedic implant-associated infections (OIAIs) is one of the most catastrophic complications following joint arthroplasty or fracture fixation. Given the increasing number of orthopaedic implants which are used annually, periprosthetic infections emerge as a global problem. Their diagnosis and consequent therapeutic management remain challenging for clinicians. Biofilm formation is a complex and only partially understood process that has not been extensively studied. Understanding the underlying mechanisms involved in biofilm formation is crucial in the amelioration of both diagnosis and therapeutic management of OIAIs. We performed a literature review of the molecular mechanisms of biofilm formation and discussed the four most common and thoroughly researched microbes of biofilm-related OIAIs.},
}

@article {pmid38736020,
year = {2024},
author = {Pozelli Macedo, MJ and Xavier-Queiroz, M and Dabul, ANG and Ricomini-Filho, AP and Hamann, PRV and Polikarpov, I},
title = {Biochemical properties of a Flavobacterium johnsoniae dextranase and its biotechnological potential for Streptococcus mutans biofilm degradation.},
journal = {World journal of microbiology & biotechnology},
volume = {40},
number = {7},
pages = {201},
pmid = {38736020},
issn = {1573-0972},
support = {2023/10037-0//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 2023/10037-0//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 2021/08780-1//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 306852/2021-7//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; },
mesh = {*Biofilms/growth & development ; *Dextranase/metabolism/genetics ; *Flavobacterium/enzymology/genetics ; *Streptococcus mutans/enzymology/genetics ; *Glycoside Hydrolases/metabolism/genetics ; Recombinant Proteins/metabolism/genetics ; Bacterial Proteins/metabolism/genetics ; Hydrolysis ; Biotechnology/methods ; },
abstract = {Cariogenic biofilms have a matrix rich in exopolysaccharides (EPS), mutans and dextrans, that contribute to caries development. Although several physical and chemical treatments can be employed to remove oral biofilms, those are only partly efficient and use of biofilm-degrading enzymes represents an exciting opportunity to improve the performance of oral hygiene products. In the present study, a member of a glycosyl hydrolase family 66 from Flavobacterium johnsoniae (FjGH66) was heterologously expressed and biochemically characterized. The recombinant FjGH66 showed a hydrolytic activity against an early EPS-containing S. mutans biofilm, and, when associated with a α-(1,3)-glucosyl hydrolase (mutanase) from GH87 family, displayed outstanding performance, removing more than 80% of the plate-adhered biofilm. The mixture containing FjGH66 and Prevotella melaninogenica GH87 α-1,3-mutanase was added to a commercial mouthwash liquid to synergistically remove the biofilm. Dental floss and polyethylene disks coated with biofilm-degrading enzymes also degraded plate-adhered biofilm with a high efficiency. The results presented in this study might be valuable for future development of novel oral hygiene products.},
}

*Biofilms/growth & development
*Dextranase/metabolism/genetics
*Flavobacterium/enzymology/genetics
*Streptococcus mutans/enzymology/genetics
*Glycoside Hydrolases/metabolism/genetics
Recombinant Proteins/metabolism/genetics
Bacterial Proteins/metabolism/genetics
Hydrolysis
Biotechnology/methods

@article {pmid38735452,
year = {2024},
author = {Pandey, P and Rao, L and Shekhar, BR and Das, DK and Vavilala, SL},
title = {Molecular Insights into Flavone-Mediated Quorum Sensing Interference: A Novel Strategy Against Serratia marcescens Biofilm-Induced Antibiotic Resistance".},
journal = {Chemico-biological interactions},
volume = {},
number = {},
pages = {111027},
doi = {10.1016/j.cbi.2024.111027},
pmid = {38735452},
issn = {1872-7786},
abstract = {Antibiotic resistance poses a significant challenge in modern medicine, urging the exploration of innovative approaches to combat bacterial infections. Biofilms, complex bacterial communities encased in a protective matrix, contribute to resistance by impeding antibiotic efficacy and promoting genetic exchange. Understanding biofilm dynamics is crucial for developing effective antimicrobial therapies against antibiotic resistance. This study explores the potential of flavone to combat biofilm-induced antibiotic resistance by employing in-vit1ro biochemical, cell biology, and In silico (MD simulation), approaches. Flavone exhibited potent antibacterial effects with a low minimum inhibitory concentration by inducing intracellular reactive oxygen species. Flavones further inhibited the formation of biofilms by 50-60% and disrupted the pre-formed biofilms by reducing the extracellular polysaccharide substance protective layer formed on the biofilm by 80 %. Quorum sensing (QS) plays a crucial role in bacterial pathogenicity and flavone significantly attenuated the production of QS-induced virulence factors like urease, protease, lipase, hemolysin and prodigiosin pigment in a dose-dependent manner. Further In-silico molecular docking studies along with Molecular Dynamic simulations run for 100 ns proved the stable binding affinity of flavone with QS-specific proteins which are crucial for biofilm formation. This study demonstrates the therapeutic potential of flavone to target QS-signaling pathway to combat S. marcescens biofilms.},
}

@article {pmid38735084,
year = {2024},
author = {Long, J and Yang, C and Liu, J and Ma, C and Jiao, M and Hu, H and Xiong, J and Zhang, Y and Wei, W and Yang, H and He, Y and Zhu, M and Yu, Y and Fu, L and Chen, H},
title = {Tannic acid inhibits Escherichia coli biofilm formation and underlying molecular mechanisms: Biofilm regulator CsgD.},
journal = {Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie},
volume = {175},
number = {},
pages = {116716},
doi = {10.1016/j.biopha.2024.116716},
pmid = {38735084},
issn = {1950-6007},
abstract = {Biofilms often engender persistent infections, heightened antibiotic resistance, and the recurrence of infections. Therefor, infections related to bacterial biofilms are often chronic and pose challenges in terms of treatment. The main transcription regulatory factor, CsgD, activates csgABC-encoded curli to participate in the composition of extracellular matrix, which is an important skeleton for biofilm development in enterobacteriaceae. In our previous study, a wide range of natural bioactive compounds that exhibit strong affinity to CsgD were screened and identified via molecular docking. Tannic acid (TA) was subsequently chosen, based on its potent biofilm inhibition effect as observed in crystal violet staining. Therefore, the aim of this study was to investigate the specific effects of TA on the biofilm formation of clinically isolated Escherichia coli (E. coli). Results demonstrated a significant inhibition of E. coli Ec032 biofilm formation by TA, while not substantially affecting the biofilm of the ΔcsgD strain. Moreover, deletion of the csgD gene led to a reduction in Ec032 biofilm formation, alongside diminished bacterial motility and curli synthesis inhibition. Transcriptomic analysis and RT-qPCR revealed that TA repressed genes associated with the csg operon and other biofilm-related genes. In conclusion, our results suggest that CsgD is one of the key targets for TA to inhibit E. coli biofilm formation. This work preliminarily elucidates the molecular mechanisms of TA inhibiting E. coli biofilm formation, which could provide a lead structure for the development of future antibiofilm drugs.},
}

@article {pmid38734101,
year = {2024},
author = {Sun, L and Yue, X and Zhang, G and Wang, A},
title = {A pilot-scale anoxic-anaerobic-anoxic-oxic combined with moving bed biofilm reactor system for advanced treatment of rural wastewater.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {173074},
doi = {10.1016/j.scitotenv.2024.173074},
pmid = {38734101},
issn = {1879-1026},
abstract = {Rural domestic poses a significant challenge to treatment technologies due to significant fluctuations in both water quality, particularly in terms of carbon concentration, and quantity. Conventional biological technology, such as anaerobic-anoxic-oxic (A[2]O) systems, is inefficient. In this work, a continuous pilot-scale anoxic-anaerobic-anoxic-oxic (A[3]O) reactor with a moving bed biofilm reactor (MBBR) system was constructed and optimized to improve the treatment efficiency of rural domestic wastewater. The sludge return ratio, volume ratio of the oxic-to-anoxic zone (Voxi/Vano), step-feeding and hydraulic retention time (HRT) at low temperature were considered the main parameters for optimization. Microbial analysis was performed on both the mixed liquor and carrier of the A3O-MBBR system under initial and post-optimized conditions. The results indicated that the A[3]O-MBBR improved the treatment efficiency of rural domestic wastewater, especially for total phosphorus (TP), which increased by 20 % compared with that of the A[2]O-MBR. In addition, the removal efficiencies of nitrogen and phosphorus were further optimized, and the average concentrations of total nitrogen (TN) and TP in the effluent reached 2.46 and 0.364 mg/L, respectively, at a sludge reflux ratio of 100 or 150 %, Voxi/Vano =200 %, step-feeding of 0.5Q/0.5Q (anaerobic/anoxic) and HRT of 15 h at low temperature in the A[3]O-MBBR, which met standard A of GB18918-2002, China (TN < 15 mg/L, TP < 0.5 mg/L). The average rate of attaining the standard increased by 58.63 % (post optimization). The microbial analysis showed an increase in species diversity and richness after the parameters were optimized. Moreover, compared to the microbial community structure before optimization, the post-optimization exhibited a more stable microbial structure with a significant enrichment of functional bacteria. Defluviimonas, Novosphingobium and Bifidobacterium, considered as the dominant nitrification or denitrifying bacteria, were enriched in the suspended sludge of the MBBR reactor, which the relative abundance increased by 3.11 %, 3.84 %, and 3.24 %, respectively. Further analysis of the microbial community in the carrier revealed that the abundance of Nitrospira and the denitrifying bacteria carried by the carrier were much greater than those in the suspended sludge. Consequently, the microorganism cooperation between suspended sludge and biofilm might be responsible for the improved performance of the optimized A[3]O-MBBR.},
}

@article {pmid38732269,
year = {2024},
author = {Di Pietro, M and Filardo, S and Mattioli, R and Bozzuto, G and Raponi, G and Mosca, L and Sessa, R},
title = {Anti-Biofilm Activity of Oleacein and Oleocanthal from Extra-Virgin Olive Oil toward Pseudomonas aeruginosa.},
journal = {International journal of molecular sciences},
volume = {25},
number = {9},
pages = {},
pmid = {38732269},
issn = {1422-0067},
support = {RP12117A7B4D7EA2//Sapienza University of Rome/ ; RM120172A35E81B1//Sapienza University of Rome/ ; RM12117A439CD073//Sapienza University of Rome/ ; FSE REACT-EU Action IV.6//Ministero dell'Istruzione e del Merito/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Pseudomonas aeruginosa/drug effects ; *Olive Oil/chemistry/pharmacology ; *Cyclopentane Monoterpenes ; *Phenols/pharmacology/chemistry ; *Aldehydes/pharmacology/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry ; Humans ; Microbial Sensitivity Tests ; Pseudomonas Infections/drug therapy/microbiology ; Bacterial Adhesion/drug effects ; },
abstract = {New antimicrobial molecules effective against Pseudomonas aeruginosa, known as an antibiotic-resistant "high-priority pathogen", are urgently required because of its ability to develop biofilms related to healthcare-acquired infections. In this study, for the first time, the anti-biofilm and anti-virulence activities of a polyphenolic extract of extra-virgin olive oil as well as purified oleocanthal and oleacein, toward P. aeruginosa clinical isolates were investigated. The main result of our study was the anti-virulence activity of the mixture of oleacein and oleocanthal toward multidrug-resistant and intermediately resistant strains of P. aeruginosa isolated from patients with ventilator-associated pneumonia or surgical site infection. Specifically, the mixture of oleacein (2.5 mM)/oleocanthal (2.5 mM) significantly inhibited biofilm formation, alginate and pyocyanin production, and motility in both P. aeruginosa strains (p < 0.05); scanning electron microscopy analysis further evidenced its ability to inhibit bacterial cell adhesion as well as the production of the extracellular matrix. In conclusion, our results suggest the potential application of the oleacein/oleocanthal mixture in the management of healthcare-associated P. aeruginosa infections, particularly in the era of increasing antimicrobial resistance.},
}

*Biofilms/drug effects/growth & development
*Pseudomonas aeruginosa/drug effects
*Olive Oil/chemistry/pharmacology
*Cyclopentane Monoterpenes
*Phenols/pharmacology/chemistry
*Aldehydes/pharmacology/chemistry
*Anti-Bacterial Agents/pharmacology/chemistry
Humans
Microbial Sensitivity Tests
Pseudomonas Infections/drug therapy/microbiology
Bacterial Adhesion/drug effects

@article {pmid38731305,
year = {2024},
author = {Yi, L and Fan, H and Yuan, S and Li, R and Wang, H and Quan, Y and Zhang, H and Wang, Y and Wang, Y},
title = {Antimicrobial Resistance and Biofilm Formation of Bordetella bronchiseptica in Central China, with Evidence of a Rare Heteroresistance Strain to Gentamicin.},
journal = {Animals : an open access journal from MDPI},
volume = {14},
number = {9},
pages = {},
doi = {10.3390/ani14091301},
pmid = {38731305},
issn = {2076-2615},
support = {32172852//National Natural Science Foundation of China/ ; 222300420005//Excellent Youth Foundation of Henan Scientific Committee/ ; 232102110095//Henan Provincial Science and Technology Research Project/ ; 24IRTSTHN033//Program for Innovative Research Team (in Science and Technology) in University of Henan Province/ ; },
abstract = {Bordetella bronchiseptica is a significant contributor to respiratory disease in pigs, leading to substantial economic losses in the swine industry worldwide. We isolated 52 B. bronchiseptica strains from 542 samples collected from pigs with atrophic rhinitis and bronchopneumonia in central China. Multi-locus sequence typing identified two prevalent sequence types: ST6 (69.23%) and ST7 (30.77%). PCR-based detection of seven virulence genes (fhaB, prn, cyaA, dnt, bteA, fla, and bfrZ) revealed that six of these genes were present in over 90% of the isolates, with bfrZ being the exception at 59.62%. Antimicrobial susceptibility testing, performed using the K-B method, demonstrated high sensitivity to enrofloxacin, polymyxin, and doxycycline but a notable resistance to tylosin, trimethoprim, tobramycin, ciprofloxacin, and amikacin. Remarkably, 86.54% of the isolates exhibited a multidrug-resistant phenotype. Notably, we successfully screened a strain of B. bronchiseptica with a heteroresistance phenotype to gentamicin using population analysis profiling, which is a rare case. Biofilm-formation assays indicated that 96.15% of the isolates possessed biofilm-forming capabilities. These findings provide crucial insights into the prevalence of B. bronchiseptica in central China, facilitating the development of effective preventive measures to safeguard both animal and human health.},
}

@article {pmid38730049,
year = {2024},
author = {Li, P and Zhang, Y and Chen, D and Lin, H},
title = {Investigation of a novel biofilm model close to the original oral microbiome.},
journal = {Applied microbiology and biotechnology},
volume = {108},
number = {1},
pages = {330},
pmid = {38730049},
issn = {1432-0614},
support = {82204253//National Natural Science Foundation of China/ ; 81970928//National Natural Science Foundation of China/ ; },
mesh = {*Biofilms/growth & development ; *Culture Media/chemistry ; *Microbiota ; *Mouth/microbiology ; Humans ; *RNA, Ribosomal, 16S/genetics ; *Saliva/microbiology ; *Bacteria/genetics/classification/isolation & purification ; Saliva, Artificial ; },
abstract = {A more optimized culture medium used in vitro to mimic the bacterial composition of original oral flora as similar as possible remains difficult at present, and the goal of this study is to develop a novel oral biofilm medium to restore the original oral microbiome. Firstly, we conducted a systematic literature review by searching PubMed and summarized the current reported culture media in vitro. Seven culture media were found. We used mixed saliva as the origin of oral species to compare the effects of the above media in culturing oral multispecies biofilms. Results indicated that among the seven media brain heart infusion containing 1% sucrose (BHIs) medium, PG medium, artificial saliva (AS) medium, and SHI medium could obviously gain large oral biofilm in vitro. The nutrients contained in different culture media may be suitable for the growth of different oral bacteria; therefore, we optimized several novel media accordingly. Notably, results of crystal violet staining showed that the biofilm cultured in our modified artificial saliva (MAS) medium had the highest amount of biofilm biomass. 16S rRNA gene sequencing showed that the operational taxonomic units (OTUs) and Shannon index of biofilm cultured in MAS medium were also the highest among all the tested media. More importantly, the 16S rRNA gene sequencing analysis indicated that the biofilm cultured in MAS medium was closer to the original saliva species. Besides, biofilm cultured by MAS was denser and produced more exopolysaccharides. MAS supported stable biofilm formation on different substrata. In conclusion, this study demonstrated a novel MAS medium that could culture oral biofilm in vitro closer to the original oral microbiome, showing a good application prospect. KEY POINTS: • We compare the effects of different media in culturing oral biofilms • A novel modified artificial saliva (MAS) medium was obtained in our study • The MAS medium could culture biofilm that was closer to oral microbiome.},
}

*Biofilms/growth & development
*Culture Media/chemistry
*Microbiota
*Mouth/microbiology
Humans
*RNA, Ribosomal, 16S/genetics
*Saliva/microbiology
*Bacteria/genetics/classification/isolation & purification
Saliva, Artificial

@article {pmid38729529,
year = {2024},
author = {Islam, N and Reid, D},
title = {Inhaled antibiotics: A promising drug delivery strategies for efficient treatment of lower respiratory tract infections (LRTIs) associated with antibiotic resistant biofilm-dwelling and intracellular bacterial pathogens.},
journal = {Respiratory medicine},
volume = {},
number = {},
pages = {107661},
doi = {10.1016/j.rmed.2024.107661},
pmid = {38729529},
issn = {1532-3064},
abstract = {Antibiotic-resistant bacteria associated with LRTIs are frequently associated with inefficient treatment outcomes. Antibiotic-resistant Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, and Staphylococcus aureus, infections are strongly associated with pulmonary exacerbations and require frequent hospital admissions, usually following failed management in the community. These bacteria are difficult to treat as they demonstrate multiple adaptational mechanisms including biofilm formation to resist antibiotic threats. Currently, many patients with the genetic disease cystic fibrosis (CF), non-CF bronchiectasis (NCFB) and chronic obstructive pulmonary disease (COPD) experience exacerbations of their lung disease and require high doses of systemically administered antibiotics to achieve meaningful clinical effects, but even with high systemic doses penetration of antibiotic into the site of infection within the lung is suboptimal. Pulmonary drug delivery technology that reliably deliver antibacterials directly into the infected cells of the lungs and penetrate bacterial biofilms to provide therapeutic doses with a greatly reduced risk of systemic adverse effects. Inhaled liposomal-packaged antibiotic with biofilm-dissolving drugs offer the opportunity for targeted, and highly effective antibacterial therapeutics in the lungs. Although the challenges with development of some inhaled antibiotics and their clinicals trials have been studied; however, only few inhaled products are available on market. This review addresses the current treatment challenges of antibiotic-resistant bacteria in the lung with some clinical outcomes and provides future directions with innovative ideas on new inhaled formulations and delivery technology that promise enhanced killing of antibiotic-resistant biofilm-dwelling bacteria.},
}

@article {pmid38729238,
year = {2024},
author = {Nosair, N and Elzayat, S and Elsharaby, R and Abdulghaffar, IA and Elfarargy, HH and Sharaf, NA},
title = {The Association of Bacterial Biofilm and Middle Ear Mucosa in Patients with Mucosal Chronic Suppurative Otitis Media.},
journal = {Acta otorrinolaringologica espanola},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.otoeng.2024.02.004},
pmid = {38729238},
issn = {2173-5735},
abstract = {OBJECTIVES: To evaluate the bacterial biofilm's role in mucosal chronic suppurative otitis media (CSOM) utilizing scanning electron microscopy (SEM).

METHODS: This study involved 123 participating patients with active and inactive mucosal CSOM who are undergoing tympanomastoid surgery. SEM was used to examine middle ear mucosa biopsies for the development of biofilms. Middle ear discharge or mucosal swabs from patients were cultured to detect any bacterial growth. The biofilm formation was correlated to the culture results.

RESULTS: The biofilm was present in 69.9 % of patients (59% of them were with active mucosal CSOM) and absent in 30.1 % of the patients (70% of them were with inactive mucosal CSOM), being more statistically significant in active mucosal CSOM (p-value = 0.003). A correlation that was statistically significant was found between active mucosal CSOM and higher grades (3 and 4) of biofilms (p-value <0.05). The mucosal CSOM type and the results of the culture had a relationship that was statistically significant (p-value <0.001). 60% of patients had positive culture (70% of them were with active mucosal CSOM). There was a statistically significant relation between Pseudomonas aeruginosa bacterial growth and active mucosal CSOM (p-value = 0.004) as well as higher grades of biofilms in mucosal CSOM.

CONCLUSION: Mucosal CSOM, especially the active type, is a biofilm-related disease. There is a significant relation between the state of mucosal CSOM (active or inactive) and culture results with predominance of Pseudomonas aeruginosa bacterial growth in active mucosal CSOM and in higher grades of biofilms in mucosal CSOM.},
}

@article {pmid38729095,
year = {2024},
author = {Liu, W and Wang, Y and Sun, Y and Xia, W and Qian, X and Bo, R and Huang, Y and Ruan, X},
title = {Baicalein inhibits biofilm formation of avian pathogenic Escherichia coli in vitro mainly by affecting adhesion.},
journal = {Research in veterinary science},
volume = {174},
number = {},
pages = {105291},
doi = {10.1016/j.rvsc.2024.105291},
pmid = {38729095},
issn = {1532-2661},
abstract = {Avian pathogenic Escherichia coli (APEC) is a widespread bacterium that causes significant economic losses to the poultry industry. APEC biofilm formation may result in chronic, persistent, and recurrent infections in clinics, making treatment challenging. Baicalein is a natural product that exhibits antimicrobial and antibiofilm activities. This study investigates the inhibitory effect of baicalein on APEC biofilm formation at different stages. The minimum inhibitory concentration (MIC) of baicalein on APEC was determined, and the growth curve of APEC biofilm formation was determined. The effects of baicalein on APEC biofilm adhesion, accumulation, and maturation were observed using optical microscopy, confocal laser scanning microscopy, and scanning electron microscopy. The biofilm inhibition rate of baicalein was calculated at different stages. The MIC of baicalein against APEC was 256 μg/mL. The process of APEC biofilm maturation takes approximately 48 h after incubation, with initial adhesion completed at 12 h, and cell accumulation finished at 24 h. Baicalein had a significant inhibitory effect on APEC biofilm formation at concentrations above 1 μg/mL (p < 0.01). Notably, baicalein had the highest rate of biofilm formation inhibition when added at the adhesion stage. Therefore, it can be concluded that baicalein is a potent inhibitor of APEC biofilm formation in vitro and acts, primarily by inhibiting cell adhesion. These findings suggests that baicalein has a potential application for inhibiting APEC biofilm formation and provides a novel approach for the prevention and control APEC-related diseases.},
}

@article {pmid38729002,
year = {2024},
author = {Jan, H and Ghayas, S and Higazy, D and Ahmad, NM and Yaghmur, A and Ciofu, O},
title = {Antibacterial and anti-biofilm activities of antibiotic-free phosphatidylglycerol/docosahexaenoic acid lamellar and non-lamellar liquid crystalline nanoparticles.},
journal = {Journal of colloid and interface science},
volume = {669},
number = {},
pages = {537-551},
doi = {10.1016/j.jcis.2024.04.186},
pmid = {38729002},
issn = {1095-7103},
abstract = {Infectious diseases, particularly those associated with biofilms, are challenging to treat due to an increased tolerance to commonly used antibiotics. This underscores the urgent need for innovative antimicrobial strategies. Here, we present an alternative simple-by-design approach focusing on the development of biocompatible and antibiotic-free nanocarriers from docosahexaenoic acid (DHA) that has the potential to combat microbial infections and phosphatidylglycerol (DOPG), which is attractive for use as a biocompatible prominent amphiphilic component of Gram-positive bacterial cell membranes. We assessed the anti-bacterial and anti-biofilm activities of these nanoformulations (hexosomes and vesicles) against S. aureus and S. epidermidis, which are the most common causes of infections on catheters and medical devices by different methods (including resazurin assay, time-kill assay, and confocal laser scanning microscopy on an in vitro catheter biofilm model). In a DHA-concentration-dependent manner, these nano-self-assemblies demonstrated strong anti-bacterial and anti-biofilm activities, particularly against S. aureus. A five-fold reduction of the planktonic and a four-fold reduction of biofilm populations of S. aureus were observed after treatment with hexosomes. The nanoparticles had a bacteriostatic effect against S. epidermidis planktonic cells but no anti-biofilm activity was detected. We discuss the findings in terms of nanoparticle-bacterial cell interactions, plausible alterations in the phospholipid membrane composition, and potential penetration of DHA into these membranes, leading to changes in their structural and biophysical properties. The implications for the future development of biocompatible nanocarriers for the delivery of DHA alone or in combination with other anti-bacterial agents are discussed, as novel treatment strategies of Gram-positive infections, including biofilm-associated infections.},
}

@article {pmid38728787,
year = {2024},
author = {Xiong, F and Dai, T and Zheng, Y and Wen, D and Li, Q},
title = {Enhanced AHL-mediated quorum sensing accelerates the start-up of biofilm reactors by elevating the fitness of fast-growing bacteria in sludge and biofilm communities.},
journal = {Water research},
volume = {257},
number = {},
pages = {121697},
doi = {10.1016/j.watres.2024.121697},
pmid = {38728787},
issn = {1879-2448},
abstract = {Quorum sensing (QS)-based manipulations emerge as a promising solution for biofilm reactors to overcome challenges from inefficient biofilm formation and lengthy start-ups. However, the ecological mechanisms underlying how QS regulates microbial behaviors and community assembly remain elusive. Herein, by introducing different levels of N-acyl-homoserine lactones, we manipulated the strength of QS during the start-up of moving bed biofilm reactors and compared the dynamics of bacterial communities. We found that enhanced QS elevated the fitness of fast-growing bacteria with high ribosomal RNA operon (rrn) copy numbers in their genomes in both the sludge and biofilm communities. This led to notably increased extracellular substance production, as evidenced by strong positive correlations between community-level rrn copy numbers and extracellular proteins and polysaccharides (Pearson's r = 0.529-0.830, P < 0.001). Network analyses demonstrated that enhanced QS significantly promoted the ecological interactions among taxa, particularly cooperative interactions. Bacterial taxa with higher network degrees were more strongly correlated with extracellular substances, suggesting their crucial roles as public goods in regulating bacterial interactions and shaping network structures. However, the assembly of more cooperative communities in QS-enhanced reactors came at the cost of decreased network stability and modularity. Null model and dissimilarity-overlap curve analysis revealed that enhanced QS strengthened stochastic processes in community assembly and rendered the universal population dynamics more convergent. Additionally, these shaping effects were consistent for both the sludge and biofilm communities, underpinning the planktonic-to-biofilm transition. This work highlights that QS manipulations efficiently drive community assembly and confer specialized functional traits to communities by recruiting taxa with specific life strategies and regulating interspecific interactions. These ecological insights deepen our understanding of the rules governing microbial societies and provide guidance for managing engineering ecosystems.},
}

@article {pmid38727840,
year = {2024},
author = {Patil, SB and Basrani, ST and Chougule, SA and Gavandi, TC and Karuppayil, SM and Jadhav, AK},
title = {Butyl isothiocyanate exhibits antifungal and anti-biofilm activity against Candida albicans by targeting cell membrane integrity, cell cycle progression and oxidative stress.},
journal = {Archives of microbiology},
volume = {206},
number = {6},
pages = {251},
pmid = {38727840},
issn = {1432-072X},
support = {DYPES/DU/R&D/2021/273//D.Y. Patil Education Society Institution Deemed to be University Kolhapur/ ; DYPES/DU/R&D/2021/273//D.Y. Patil Education Society Institution Deemed to be University Kolhapur/ ; DYPES/DU/R&D/2021/273//D.Y. Patil Education Society Institution Deemed to be University Kolhapur/ ; },
mesh = {*Candida albicans/drug effects/physiology ; *Biofilms/drug effects ; *Antifungal Agents/pharmacology ; *Isothiocyanates/pharmacology ; *Oxidative Stress/drug effects ; *Cell Membrane/drug effects/metabolism ; *Reactive Oxygen Species/metabolism ; Microbial Sensitivity Tests ; Cell Cycle/drug effects ; Hyphae/drug effects/growth & development ; Ergosterol/metabolism ; },
abstract = {The prevalence of Candida albicans infection has increased during the past few years, which contributes to the need for new, effective treatments due to the increasing concerns regarding antifungal drug toxicity and multidrug resistance. Butyl isothiocyanate (butylITC) is a glucosinolate derivative, and has shown a significant antifungal effect contrary to Candida albicans. Additionally, how butylITC affects the virulence traits of C. albicans and molecular mode of actions are not well known. Present study shows that at 17.36 mM concentration butylITC inhibit planktonic growth. butylITC initially slowed the hyphal transition at 0.542 mM concentration. butylITC hampered biofilm development, and inhibits biofilm formation at 17.36 mM concentration which was analysed using metabolic assay (XTT assay) and Scanning Electron Microscopy (SEM). In addition, it was noted that butylITC inhibits ergosterol biosynthesis. The permeability of cell membranes was enhanced by butylITC treatment. Moreover, butylITC arrests cells at S-phase and induces intracellular Reactive Oxygen Species (ROS) accumulation in C. albicans. The results suggest that butylITC may have a dual mode of action, inhibit virulence factors and modulate cellular processes like inhibit ergosterol biosynthesis, cell cycle arrest, induces ROS production which leads to cell death in C. albicans.},
}

*Candida albicans/drug effects/physiology
*Biofilms/drug effects
*Antifungal Agents/pharmacology
*Isothiocyanates/pharmacology
*Oxidative Stress/drug effects
*Cell Membrane/drug effects/metabolism
*Reactive Oxygen Species/metabolism
Microbial Sensitivity Tests
Cell Cycle/drug effects
Hyphae/drug effects/growth & development
Ergosterol/metabolism

@article {pmid38726949,
year = {2024},
author = {Ding, M and Zhang, Y and Li, X and Li, Q and Xiu, W and He, A and Dai, Z and Dong, H and Shan, J and Mou, Y},
title = {Simultaneous Biofilm Disruption, Bacterial Killing, and Inflammation Elimination for Wound Treatment Using Silver Embellished Polydopamine Nanoplatform.},
journal = {Small (Weinheim an der Bergstrasse, Germany)},
volume = {},
number = {},
pages = {e2400927},
doi = {10.1002/smll.202400927},
pmid = {38726949},
issn = {1613-6829},
support = {82301104//National Natural Science Foundation of China/ ; BK20230160//Natural Science Foundation of Jiangsu Province/ ; YKK22182//Nanjing Medical Science and Technique Development Foundation/ ; 0222R208//"3456" Cultivation Program for Junior Talents of Nanjing Stomatological Hospital, Medical School of Nanjing University/ ; 0222R212//"3456" Cultivation Program for Junior Talents of Nanjing Stomatological Hospital, Medical School of Nanjing University/ ; 2019060009//Nanjing Clinical Research Center for Oral Diseases/ ; },
abstract = {Due to the presence of spatial barriers, persistent bacteria, and excessive inflammation in bacteria biofilm-infected wounds, current nanoplatforms cannot effectively address these issues simultaneously during the therapeutic process. Herein, a novel biomimetic photothermal nanoplatform integrating silver and polydopamine nanoparticles (Ag/PDAs) that can damage biofilms, kill bacterial persisters, and reduce inflammation for wound treatment is presented. These findings reveal that Ag/PDAs exhibit a broad-spectrum antimicrobial activity through direct damage to the bacterial membrane structure. Additionally, Ag/PDAs demonstrate a potent photothermal conversion efficiency. When combined with near-infrared (NIR) irradiation, Ag/PDAs effectively disrupt the spatial structure of biofilms and synergistically eradicate the resident bacteria. Furthermore, Ag/PDAs show remarkable anti-inflammatory properties in counteracting bacterium-induced macrophage polarization. The in vivo results confirm that the topical application of Ag/PDAs significantly suppress Staphylococcus aureus biofilm-infected wounds in murine models, concurrently facilitating wound healing. This research provides a promising avenue for the eradication of bacterial biofilms and the treatment of biofilm-infected wounds.},
}

@article {pmid38725978,
year = {2024},
author = {Okouakoua, FY and Kayath, CA and Mokemiabeka, SN and Moukala, DCR and Kaya-Ongoto, MD and Nguimbi, E},
title = {Involvement of the Bacillus SecYEG Pathway in Biosurfactant Production and Biofilm Formation.},
journal = {International journal of microbiology},
volume = {2024},
number = {},
pages = {6627190},
pmid = {38725978},
issn = {1687-918X},
abstract = {With Bacillus species, about 30% of extracellular proteins are translocated through the cytoplasmic membrane, coordinated by the Sec translocase. This system mainly consists of the cytoplasmic ATPase SecA and the membrane-embedded SecYEG channel. The purpose of this work was to investigate the effects of the SecYEG export system on the production of industrial biomolecules, such as biosurfactants, proteases, amylases, and cellulases. Fifty-two isolates of Bacillus species were obtained from traditional fermented foods and then characterized using molecular microbiology methods. The isolates secreted exoenzymes that included cellulases, amylases, and proteases. We present evidence that a biosurfactant-like molecule requires the SecA ATPase and the SecYEG membrane channel for its secretion. In addition, we showed that biomolecules involved in biofilm formation required the SecYEG pathway. This work presents a novel seven-target fragment multiplex PCR assay capable of identification at the species level of Bacillus through a unique SecDF chromosomal gene. The bacterial membrane protein SecDF allowed the discrimination of Bacillus subtilis, B. licheniformis, B. amyloliquefaciens, and B. sonorensis. SecA was able to interact with AprE, AmyE, and TasA. The Rose Bengal inhibitor of SecA crucially affected the interaction of AprE, AmyE, TapA, and TasA with recombinant Gst-SecA. The Rose Bengal prevented Bacillus species from secreting and producing proteases, cellulases, amylases, and biosurfactant-like molecules. It also inhibited the formation of biofilm cell communities. The data support, for the first time, that the SecYEG translocon mediates the secretion of a biosurfactant-like molecule.},
}

@article {pmid38724834,
year = {2024},
author = {Nayak, R and Rai, VK and Pradhan, D and Halder, J and Rajwar, TK and Dash, P and Das, C and Mishra, A and Mahanty, R and Saha, I and Manoharadas, S and Kar, B and Ghosh, G and Rath, G},
title = {Exploring the Biofilm Inhibition Potential of a Novel Phytic Acid-Crosslinked Chitosan Nanoparticle: In Vitro and In Vivo Investigations.},
journal = {AAPS PharmSciTech},
volume = {25},
number = {5},
pages = {106},
pmid = {38724834},
issn = {1530-9932},
mesh = {*Chitosan/chemistry ; *Biofilms/drug effects ; *Nanoparticles/chemistry ; *Antifungal Agents/pharmacology/administration & dosage ; Animals ; *Candida albicans/drug effects ; Mice ; *Microbial Sensitivity Tests/methods ; *Phytic Acid/pharmacology/administration & dosage/chemistry ; Female ; Candidiasis/drug therapy ; Particle Size ; Drug Carriers/chemistry ; Cross-Linking Reagents/chemistry ; Cytokines/metabolism ; },
abstract = {The primary factor underlying the virulence of Candida albicans is its capacity to form biofilms, which in turn leads to recurrent complications. Over-the-counter antifungal treatments have proven ineffective in eliminating fungal biofilms and the inflammatory cytokines produced during fungal infections. Chitosan nanoparticles offer broad and versatile therapeutic potential as both antifungal agents and carriers for antifungal drugs to combat biofilm-associated Candida infections. In our study, we endeavoured to develop chitosan nanoparticles utilising chitosan and the antifungal crosslinker phytic acid targeting C. albicans. Phytic acid, known for its potent antifungal and anti-inflammatory properties, efficiently crosslinks with chitosan. The nanoparticles were synthesised using the ionic gelation technique and subjected to analyses including Fourier transform infrared spectroscopy, dynamic light scattering, and zeta potential analysis. The synthesised nanoparticles exhibited dimensions with a diameter (Dh) of 103 ± 3.9 nm, polydispersity index (PDI) of 0.33, and zeta potential (ZP) of 37 ± 2.5 mV. These nanoparticles demonstrated an antifungal effect with a minimum inhibitory concentration (MIC) of 140 ± 2.2 µg/mL, maintaining cell viability at approximately 90% of the MIC value and reducing cytokine levels. Additionally, the nanoparticles reduced ergosterol content and exhibited a 62% ± 1.2 reduction in biofilm susceptibility, as supported by colony-forming unit (CFU) and XTT assays-furthermore, treatment with nanoparticles reduced exopolysaccharide production and decreased secretion of aspartyl protease by C. albicans. Our findings suggest that the synthesised nanoparticles effectively combat Candida albicans infections. In vivo studies conducted on a mouse model of vaginal candidiasis confirmed the efficacy of the nanoparticles in combating fungal infections in vivo.},
}

*Chitosan/chemistry
*Biofilms/drug effects
*Nanoparticles/chemistry
*Antifungal Agents/pharmacology/administration & dosage
Animals
*Candida albicans/drug effects
Mice
*Microbial Sensitivity Tests/methods
*Phytic Acid/pharmacology/administration & dosage/chemistry
Female
Candidiasis/drug therapy
Particle Size
Drug Carriers/chemistry
Cross-Linking Reagents/chemistry
Cytokines/metabolism

@article {pmid38723991,
year = {2024},
author = {Xie, Z and Ou, Z and Zhang, M and Tang, G and Cheng, X and Cao, W and Luo, J and Fang, F and Sun, Y and Li, M and Cai, J and Feng, Q},
title = {Indole-3-acetic acid regulating the initial adhesion of microalgae in biofilm formation.},
journal = {Environmental research},
volume = {},
number = {},
pages = {119093},
doi = {10.1016/j.envres.2024.119093},
pmid = {38723991},
issn = {1096-0953},
abstract = {Regulating the microalgal initial adhesion in biofilm formation is a key approach to address the challenges of attached microalgae cultivation. As a type of phytohormone, Indole-3-acetic acid (IAA) can promote the growth and metabolism of microalgae. However, limited knowledge has been acquired of how IAA can change the initial adhesion of microalgae in biofilm formation. This study focused on investigating the initial adhesion of microalgae under different IAA concentrations exposure in biofilm formation. The results showed that IAA showed obvious hormesis-like effects on the initial adhesion ability of microalgae biofilm.. Under exposure to the low concentration (0.1mg/L) of IAA, the initial adhesion quantity of microalgae on the surface of the carrier reached the highest value of 7.2 g/m[2]. However, exposure to the excessively high concentration (10mg/L) of IAA led to a decrease in the initial adhesion capability of microalgal biofilms. The enhanced adhesion of microalgal biofilms due to IAA was attributed to the upregulation of genes related to the Calvin Cycle, which promoted the synthesis of hydrophobic amino acids, leading to increased protein secretion and altering the surface electron donor characteristics of microalgal biofilms. This, in turn, reduced the energy barrier between the carriers and microalgae. The research findings would provide crucial support for the application of IAA in regulating the operation of microalgal biofilm systems.},
}

@article {pmid38723954,
year = {2024},
author = {Wu, T and Ding, J and Wang, S and Pang, JW and Sun, HJ and Zhong, L and Ren, NQ and Yang, SS},
title = {Insight into effect of polyethylene microplastic on nitrogen removal in moving bed biofilm reactor: Focusing on microbial community and species interactions.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {173033},
doi = {10.1016/j.scitotenv.2024.173033},
pmid = {38723954},
issn = {1879-1026},
abstract = {Microplastics (MPs) pollution has emerged as a global concern, and wastewater treatment plants (WWTPs) are one of the potential sources of MPs in the environment. However, the effect of polyethylene MPs (PE) on nitrogen (N) removal in moving bed biofilm reactor (MBBR) remains unclear. We hypothesized that PE would affect N removal in MBBR by influencing its microbial community. In this study, we investigated the impacts of different PE concentrations (100, 500, and 1000 μg/L) on N removal, enzyme activities, and microbial community in MBBR. Folin-phenol and anthrone colorimetric methods, oxidative stress and enzyme activity tests, and high-throughput sequencing combined with bioinformation analysis were used to decipher the potential mechanisms. The results demonstrated that 1000 μg/L PE had the greatest effect on NH4[+]-N and TN removal, with a decrease of 33.5 % and 35.2 %, and nitrifying and denitrifying enzyme activities were restrained by 29.5-39.6 % and 24.6-47.4 %. Polysaccharide and protein contents were enhanced by PE, except for 1000 μg/L PE, which decreased protein content by 65.4 mg/g VSS. The positive links of species interactions under 1000 μg/L PE exposure was 52.07 %, higher than under 500 μg/L (51.05 %) and 100 μg/L PE (50.35 %). Relative abundance of some metabolism pathways like carbohydrate metabolism and energy metabolism were restrained by 0.07-0.11 % and 0.27-0.4 %. Moreover, the total abundance of nitrification and denitrification genes both decreased under PE exposure. Overall, PE reduced N removal by affecting microbial community structure and species interactions, inhibiting some key metabolic pathways, and suppressing key enzyme activity and functional gene abundance. This paper provides new insights into assessing the risk of MPs to WWTPs, contributing to ensuring the health of aquatic ecosystems.},
}

@article {pmid38723731,
year = {2024},
author = {Wang, J and Guo, Y and Lu, W and Liu, X and Zhang, J and Sun, J and Chai, G},
title = {Dry powder inhalation containing muco-inert ciprofloxacin and colistin co-loaded liposomes for pulmonary P. Aeruginosa biofilm eradication.},
journal = {International journal of pharmaceutics},
volume = {},
number = {},
pages = {124208},
doi = {10.1016/j.ijpharm.2024.124208},
pmid = {38723731},
issn = {1873-3476},
abstract = {Pseudomonas aeruginosa (PA), a predominant pathogen in lung infections, poses significant challenges due to its biofilm formation, which is the primary cause of chronic and recalcitrant pulmonary infections. Bacteria within these biofilms exhibit heightened resistance to antibiotics compared to their planktonic counterparts, and their secreted toxins exacerbate lung infections. Diverging from traditional antibacterial therapy for biofilm eradication, this study introduces a novel dry powder inhalation containing muco-inert ciprofloxacin and colistin co-encapsulated liposomes (Cipro-Col-Lips) prepared using ultrasonic spray freeze drying (USFD) technique. This USFD dry powder is designed to efficiently deliver muco-inert Cipro-Col-Lips to the lungs. Once deposited, the liposomes rapidly diffuse into the airway mucus, reaching the biofilm sites. The muco-inert Cipro-Col-Lips neutralize the biofilm-secreted toxins and simultaneously trigger the release of their therapeutic payload, exerting a synergistic antibiofilm effect. Our results demonstrated that the optimal USFD liposomal dry powder formulation exhibited satisfactory in vitro aerosol performance in terms of fine particle fraction (FPF) of 44.44 ± 0.78 %, mass median aerodynamic diameter (MMAD) of 4.27 ± 0.21 μm, and emitted dose (ED) of 99.31 ± 3.31 %. The muco-inert Cipro-Col-Lips effectively penetrate the airway mucus and accumulate at the biofilm site, neutralizing toxins and safeguarding lung cells. The triggered release of ciprofloxacin and colistin works synergistically to reduce the biofilm's antibiotic resistance, impede the development of antibiotic resistance, and eliminate 99.99 % of biofilm-embedded bacteria, including persister bacteria. Using a PA-beads induced biofilm-associated lung infection mouse model, the in vivo efficacy of this liposomal dry powder aerosol was tested, and the results demonstrated that this liposomal dry powder aerosol achieved a 99.7 % reduction in bacterial colonization, and significantly mitigated inflammation and pulmonary fibrosis. The USFD dry powder inhalation containing muco-inert Cipro-Col-Lips emerges as a promising therapeutic strategy for treating PA biofilm-associated lung infections.},
}

@article {pmid38723699,
year = {2024},
author = {Jo, S and Chao, C and Khilnani, TK and Shenoy, A and Bostrom, MPG and Carli, AV},
title = {The Infected Polypropylene Mesh: When Does Biofilm Form and Which Antiseptic Solution Most Effectively Removes It?.},
journal = {The Journal of arthroplasty},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.arth.2024.04.081},
pmid = {38723699},
issn = {1532-8406},
abstract = {BACKGROUND: Polypropylene (PPE) mesh is commonly utilized to reconstruct catastrophic extensor mechanism disruptions in revision total knee arthroplasty. Unfortunately, these procedures are associated with a high rate of periprosthetic joint infection (PJI). The purpose of the current study was to: 1) visualize and quantify the progression of bacterial biofilm growth on PPE-mesh; and 2) determine which antiseptic solutions effectively remove viable bacteria.

METHODS: Knitted PPE mesh samples were cultured with either methicillin-sensitive Staphylococcus aureus (MSSA) or Escherichia coli (E. coli) for 7 days, with regular quantification of colony forming units (CFUs) and visualization using scanning electron microscopy (SEM) to identify maturity. Immature (24 hour) and mature (72 hour) biofilm was treated with one of five commercial antiseptics for three minutes. A 0.05% chlorhexidine gluconate, a surfactant-based formulation of ethanol, acetic acid, sodium acetate, benzalkonium chloride, diluted povidone-iodine (0.35%), undiluted (10%) povidone-iodine, and 1:1 combination of 10% povidone-iodine and 3% hydrogen peroxide. A three-log reduction in colony-forming units (CFUs) compared to saline was considered clinically meaningful.

RESULTS: The CFU counts plateaued, indicating maturity, at 72 hours for both MSSA and E. coli. The SEM confirmed confluent biofilm formation after 72 hours. The 10% povidone-iodine was clinically effective against all MSSA biofilms and immature E. coli biofilms. The 10% povidone-iodine with hydrogen peroxide was effective in all conditions. Only 10% povidone iodine formulations produced significantly (P < 0.0083) reduced CFU counts against mature biofilms.

CONCLUSION: Bacteria rapidly form biofilm on PPE mesh. Mesh contamination can be catastrophic, and clinicians should consider utilizing an antiseptic solution at the conclusion of mesh implantation. Undiluted povidone-iodine with hydrogen peroxide should be considered when attempting to salvage infected PPE mesh.},
}

@article {pmid38723695,
year = {2024},
author = {Kim, BH and Ashrafudoulla, M and Shaila, S and Park, HJ and Sul, JD and Park, SH and Ha, SD},
title = {Isolation, characterization, and application of bacteriophage on Vibrio parahaemolyticus biofilm to control seafood contamination.},
journal = {International journal of antimicrobial agents},
volume = {},
number = {},
pages = {107194},
doi = {10.1016/j.ijantimicag.2024.107194},
pmid = {38723695},
issn = {1872-7913},
abstract = {This study intended to isolate a Vibrio-particular phage from the natural environment, analyze its characteristics and genome sequence, and investigate its reduction effect on V. parahaemolyticus biofilm as a biocontrol agent in squid and mackerel. Among 21 phages, phage CAU_VPP01, isolated from beach mud, was chosen for further experiments based on host range and EOP tests. When examining the reduction effect of phage CAU_VPP01 against Vibrio parahaemolyticus biofilms on surfaces (stainless steel [SS] and polyethylene terephthalate [PET]) and food surfaces (squid and mackerel), the phage showed the most excellent reduction effect at a multiplicity-of-infection (MOI) 10. Three-dimensional images acquired with confocal laser scanning microscopy (CLSM) analysis were quantified using COMSTAT, which showed that biomass, average thickness, and roughness coefficient decreased when treated with the phage. Color and texture analysis confirmed that the quality of squid and mackerel was maintained after the phage treatment. Finally, a comparison of gene expression levels determined by qRT-PCR analysis showed that the phage treatment induced a decrease in the gene expression of flaA, vp0962, and luxS, as examples. This study indicated that Vibrio-specific phage CAU_VPP01 effectively controlled V. parahaemolyticus biofilms under various conditions and confirmed that the isolated phage could possibly be used as an effective biocontrol weapon in the seafood manufacturing industry.},
}

@article {pmid38723502,
year = {2024},
author = {Yan, Z and Han, X and Wang, H and Jin, Y and Song, X},
title = {Influence of aeration modes and DO on simultaneous nitrification and denitrification in treatment of hypersaline high-strength nitrogen wastewater using sequencing batch biofilm reactor (SBBR).},
journal = {Journal of environmental management},
volume = {359},
number = {},
pages = {121075},
doi = {10.1016/j.jenvman.2024.121075},
pmid = {38723502},
issn = {1095-8630},
abstract = {Sequencing batch biofilm reactor (SBBR) has the potential to treat hypersaline high-strength nitrogen wastewater by simultaneous nitrification-denitrification (SND). Dissolved oxygen (DO) and aeration modes are major factors affecting pollutant removal. Low DO (0.35-3.5 mg/L) and alternative anoxic/aerobic (A/O) mode are commonly used for municipal wastewater treatment, however, the appropriate DO concentration and operation mode are still unknown under hypersaline environment because of the restricted oxygen transfer in denser extracellular polymeric substances (EPS) barrier and the decreased carbon source consumption during the anoxic phase. Herein, two SBBRs (R1, fully aerobic mode; R2, A/O mode) were used for the treatment of hypersaline high-strength nitrogen wastewater (200 mg/L NH4[+]-N, COD/N of 3 and 3% salinity). The results showed that the relatively low DO (2 mg/L) could not realize effective nitrification, while high DO (4.5 mg/L) evidently increased nitrification efficiency by enhancing oxygen transfer in denser biofilm that was stimulated by high salinity. A stable SND was reached 16 days faster with a ∼10% increase of TN removal under A/O mode. Mechanism analysis found that denser biofilm with coccus and bacillus were present in A/O mode instead of filamentous microorganisms, with the secretion of more EPS. Corynebacterium and Halomonas were the dominant genera in both SBBRs, and HN-AD process might assist partial nitrification-denitrification (PND) for highly efficient TN removal in biofilm systems. By using the appropriate operation mode and parameters, the average NH4[+]-N and TN removal efficiency could respectively reach 100% and 70.8% under the NLR of 0.2 kg N·m[-3]·d[-1] (COD/N of 3), which was the highest among the published works using SND-based SBBRs in treatment of saline high-strength ammonia nitrogen (low COD/N) wastewater. This study provided new insights in biofilm under hypersaline stress and provided a solution for the treatment of hypersaline high-strength nitrogen (low COD/N) water.},
}

@article {pmid38723421,
year = {2024},
author = {Reis-Neta, GRD and Ricomini-Filho, AP and Martorano-Fernandes, L and Vargas-Moreno, VF and Cury, AADB and Marcello-Machado, RM},
title = {Effect of hydroxyapatite nanoparticles coating of titanium surface on biofilm adhesion: An in vitro study.},
journal = {Archives of oral biology},
volume = {164},
number = {},
pages = {105986},
doi = {10.1016/j.archoralbio.2024.105986},
pmid = {38723421},
issn = {1879-1506},
abstract = {AIM: To evaluate the adhesion of mono and duospecies biofilm on a commercially available dental implant surface coated with hydroxyapatite nanoparticles (nanoHA).

MATERIAL AND METHODS: Titanium discs were divided into two groups: double acid-etched (AE) and AE coated with nanoHA (NanoHA). Surface characteristics evaluated were morphology, topography, and wettability. Mono and duospecies biofilms of Streptococcus sanguinis (S. sanguinis) and Candida albicans (C. albicans) were formed. Discs were exposed to fetal bovine serum (FBS) to form the pellicle. Biofilm was growth in RPMI1640 medium with 10% FBS and 10% BHI medium for 6 h. Microbial viability was evaluated using colony-forming unit and metabolic activity by a colorimetric assay of the tetrazolium salt XTT. Biofilm architecture and organization were evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM).

RESULTS: AE surface had more pores, while NanoHA had even nanoHA crystals distribution. Roughness was similar (AE: 0.59 ± 0.07 µm, NanoHA: 0.69 ± 0.18 µm), but wettability was different (AE: Θw= 81.79 ± 8.55°, NanoHA: Θw= 53.26 ± 11.86°; P = 0.01). NanoHA had lower S. sanguinis viability in monospecies biofilm (P = 0.007). Metabolic activity was similar among all biofilms. In SEM both surfaces on C. albicans biofilm show a similar distribution of hyphae in mono and duospecies biofilms. AE surface has more S. sanguinis than the NanoHA surface in the duospecies biofilm. CLSM showed a large proportion of live cells in all groups.

CONCLUSIONS: The nanoHA surface reduced the adhesion of S. sanguinis biofilm but did not alter the adhesion of C. albicans or the biofilm formed by both species.},
}

@article {pmid38723349,
year = {2024},
author = {Zhang, H and Cheng, Y and Qiu, L and Zeng, W and Hu, T and Yang, J and Wang, J and Wang, H and Gong, W and Liang, H},
title = {In situ electron generation through Fe/C supported sludge coupled with a counter-diffusion biofilm for electron-deficient wastewater treatment: Binding properties and catalytic competition mechanism of nitrate reductase.},
journal = {Water research},
volume = {257},
number = {},
pages = {121688},
doi = {10.1016/j.watres.2024.121688},
pmid = {38723349},
issn = {1879-2448},
abstract = {A membrane-aerated biofilm-coupled Fe/C supported sludge system (MABR-Fe/C) was constructed to achieve in situ electron production for NO3[-]-N reduction enhancement in different Fe/C loadings (10 g and 200 g). The anoxic environment formed in the MABR-Fe/C promoted a continual Fe[2+]release of Fe/C in 120 d operation (average Fe[2+]concentrations is 1.18 and 2.95 mg/L in MABR-Fe/C10 and MABR-Fe/C200, respectively). Metagenomics results suggested that the electrons generated from ongoing Fe[2+] oxidation were transferred via the Quinone pool to EC 1.7.5.1 rather than EC 1.9.6.1 to complete the process of NO3[-]-N reduction to NO2[-]-N in Acidovorax, Ottowia, and Polaromonas. In the absence of organic matter, the NO3[-]-N removal in MABR-Fe/C10 and MABR-Fe/C200 increased by 11.99 and 12.52 mg/L, respectively, compared to that in MABR. In the further NO2[-]-N reduction, even if the minimum binding free energy (MBFE) was low, NO2[-]-N in Acidovorax and Dechloromonas preferentially bind the Gln-residues for dissimilatory nitrate reduction (DNR) in the presence of Fe/C. Increasing Fe/C loading (MABR-Fe/C200) caused the formation of different residue binding sites, further enhancing the already dominant DNR. When DNR in MABR-Fe/C200 intensified, the TN in the effluent increased by 3.75 mg/L although the effluent NO3[-]-N concentration was lower than that in MABR-Fe/C10. This study demonstrated a new MABR-Fe/C system for in situ electron generation to enhance biological nitrogen removal and analyzed the NO3[-]-N reduction pathway and metabolic mechanism, thus providing new ideas for nitrogen removal in electron-deficient wastewater.},
}

@article {pmid38722774,
year = {2024},
author = {Noori, R and Bano, N and Ahmad, S and Mirza, K and Mazumder, JA and Perwez, M and Raza, K and Manzoor, N and Sardar, M},
title = {Microbial Biofilm Inhibition Using Magnetic Cross-Linked Polyphenol Oxidase Aggregates.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.4c00175},
pmid = {38722774},
issn = {2576-6422},
abstract = {Microbial biofilm accumulation poses a serious threat to the environment, presents significant challenges to different industries, and exhibits a large impact on public health. Since there has not been a conclusive answer found despite various efforts, the potential green and economical methods are being focused on, particularly the innovative approaches that employ biochemical agents. In the present study, we propose a bio-nanotechnological method using magnetic cross-linked polyphenol oxidase aggregates (PPO m-CLEA) for inhibition of microbial biofilm including multidrug resistant bacteria. Free PPO solution showed only 55-60% biofilm inhibition, whereas m-CLEA showed 70-75% inhibition, as confirmed through microscopic techniques. The carbohydrate and protein contents in biofilm extracellular polymeric substances (EPSs) were reduced significantly. The m-CLEA demonstrated reusability up to 5 cycles with consistent efficiency in biofilm inhibition. Computational work was also done where molecular docking of PPO with microbial proteins associated with biofilm formation was conducted, resulting in favorable binding scores and inter-residual interactions. Overall, both in vitro and in silico results suggest that PPO interferes with microbial cell attachment and EPS formation, thereby preventing biofilm colonization.},
}

@article {pmid38722243,
year = {2024},
author = {Perasoli, FB and B Silva, LS and C Figueiredo, BI and Pinto, IC and F Amaro, LJ and S Almeida Bastos, JC and Carneiro, SP and R Araújo, VP and G Beato, FR and M Barboza, AP and M Teixeira, LF and Gallagher, MP and Bradley, M and Venkateswaran, S and H Dos Santos, OD},
title = {Poly(methylmethacrylate-co-dimethyl acrylamide)-silver nanocomposite prevents biofilm formation in medical devices.},
journal = {Nanomedicine (London, England)},
volume = {},
number = {},
pages = {},
doi = {10.1080/17435889.2024.2345044},
pmid = {38722243},
issn = {1748-6963},
support = {//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; 01//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; APQ02429-22, APQ01953-22//Fundação de Amparo à Pesquisa do Estado de Minas Gerais/ ; },
abstract = {Aim: To investigate whether medical devices coated with a synthesized nanocomposite of poly(methylmethacrylate-co-dimethyl acrylamide) (PMMDMA) and silver nanoparticles (AgNPs) could improve their antibiofilm and antimicrobial activities. We also investigated the nanocomposite's safety. Materials & methods: The nanocomposite was synthesized and characterized using analytical techniques. Medical devices coated with the nanocomposite were evaluated for bacterial adhesion and hemolytic activity in vitro. Results: The nanocomposite formation was demonstrated with the incorporation of AgNPs into the polymer matrix. The nanocomposite proved to be nonhemolytic and significantly inhibited bacterial biofilm formation. Conclusion: The PMMDMA-AgNPs nanocomposite was more effective in preventing biofilm formation than PMMDMA alone and is a promising strategy for coating medical devices and reducing mortality due to hospital-acquired infections.},
}

@article {pmid38722159,
year = {2024},
author = {Jarrett, CO and Leung, JM and Motoshi, S and Sturdevant, DE and Zhang, Y and Hoyt, FH and Hinnebusch, BJ},
title = {Role of the Yersinia pestis phospholipase D (Ymt) in the initial aggregation step of biofilm formation in the flea.},
journal = {mBio},
volume = {},
number = {},
pages = {e0012424},
doi = {10.1128/mbio.00124-24},
pmid = {38722159},
issn = {2150-7511},
abstract = {UNLABELLED: Transmission of Yersinia pestis by fleas depends on the formation of condensed bacterial aggregates embedded within a gel-like matrix that localizes to the proventricular valve in the flea foregut and interferes with normal blood feeding. This is essentially a bacterial biofilm phenomenon, which at its end stage requires the production of a Y. pestis exopolysaccharide that bridges the bacteria together in a cohesive, dense biofilm that completely blocks the proventriculus. However, bacterial aggregates are evident within an hour after a flea ingests Y. pestis, and the bacterial exopolysaccharide is not required for this process. In this study, we characterized the biochemical composition of the initial aggregates and demonstrated that the yersinia murine toxin (Ymt), a Y. pestis phospholipase D, greatly enhances rapid aggregation following infected mouse blood meals. The matrix of the bacterial aggregates is complex, containing large amounts of protein and lipid (particularly cholesterol) derived from the flea's blood meal. A similar incidence of proventricular aggregation occurred after fleas ingested whole blood or serum containing Y. pestis, and intact, viable bacteria were not required. The initial aggregation of Y. pestis in the flea gut is likely due to a spontaneous physical process termed depletion aggregation that occurs commonly in environments with high concentrations of polymers or other macromolecules and particles such as bacteria. The initial aggregation sets up subsequent binding aggregation mediated by the bacterially produced exopolysaccharide and mature biofilm that results in proventricular blockage and efficient flea-borne transmission.

IMPORTANCE: Yersinia pestis, the bacterial agent of plague, is maintained in nature in mammal-flea-mammal transmission cycles. After a flea feeds on a mammal with septicemic plague, the bacteria rapidly coalesce in the flea's digestive tract to form dense aggregates enveloped in a viscous matrix that often localizes to the foregut. This represents the initial stage of biofilm development that potentiates transmission of Y. pestis when the flea later bites a new host. The rapid aggregation likely occurs via a depletion-aggregation mechanism, a non-canonical first step of bacterial biofilm development. We found that the biofilm matrix is largely composed of host blood proteins and lipids, particularly cholesterol, and that the enzymatic activity of a Y. pestis phospholipase D (Ymt) enhances the initial aggregation. Y. pestis transmitted by flea bite is likely associated with this host-derived matrix, which may initially shield the bacteria from recognition by the host's intradermal innate immune response.},
}

@article {pmid38721917,
year = {2024},
author = {Wang, J and Mao, D and Dai, B and Rui, Y},
title = {Silicon-induced biofilm improves peripheral nerve defect in rats mediated by VEGF/VEGFR2/ERK.},
journal = {Neurological research},
volume = {},
number = {},
pages = {1-9},
doi = {10.1080/01616412.2024.2352232},
pmid = {38721917},
issn = {1743-1328},
abstract = {Background: Injury of peripheral nerve capable of regeneration with much poorer prognosis affects people's life quality. The recovery of nerve function after transplantation for peripheral nerve injury remain a worldwide problem. Silicon-induced biofilms as vascularized biological conduits can promote nerve regeneration by encapsulating autologous or allogeneic nerve graft.Objective: We proposed to explore the effect of silicon-induced biofilms on nerves regeneration and whether the VEGF/VEGFR2/ERK pathway was involved in the present study.Methods: Biofilms around the transplanted nerves in peripheral nerve injury rats were induced by silicon. Vascularization and proteins related to VEGF/VEGFR2/ERK were measured. Pathology and morphology of nerves were investigated after encapsulating the transplanted nerves by silicon-induced biofilms.Results: Our results indicated that the biofilms induced by silicon for 6 weeks showed the most intensive vascularization and the optimal effect on nerve regeneration. Moreover, silicon-induced biofilms for 4, 6 and 8 weeks could significantly secrete VEGF with the highest content at week 6 after induction. VEGFR2, VEGF, p-VEGFR2, ERK1, ERK2, p-ERK1 and p-ERK2 were expressed in the biofilms. p-VEGFR2, p-ERK1 and p-ERK2 expression were different at each time point and significantly increased at week 6 compared with that at week 4 or week 8 which was consistent with that 6 week of was the optimum time for biofilms induction to improve the nerve repair after peripheral nerve injury.Conclusion: Our results suggested that combination of silicon-induced autologous vascularized biofilm and autologous transplantation may promote the repair of rat sciatic nerve defect quickly through VEGF/VEGFR2/ERK pathway.},
}

@article {pmid38720923,
year = {2024},
author = {Ezeh, CK and Dibua, MEU},
title = {Anti-biofilm, drug delivery and cytotoxicity properties of dendrimers.},
journal = {ADMET & DMPK},
volume = {12},
number = {2},
pages = {239-267},
pmid = {38720923},
issn = {1848-7718},
abstract = {BACKGROUND AND PURPOSE: Treatments using antimicrobial agents have faced many difficulties as a result of biofilm formation by pathogenic microorganisms. The biofilm matrix formed by these microorganisms prevents antimicrobial agents from penetrating the interior where they can exact their activity effectively. Additionally, extracellular polymeric molecules associated with biofilm surfaces can absorb antimicrobial compounds, lowering their bioavailability. This problem has resulted in the quest for alternative treatment protocols, and the development of nanomaterials and devices through nanotechnology has recently been on the rise.

RESEARCH APPROACH: The literature on dendrimers was searched for in databases such as Google Scholar, PubMed, and ScienceDirect.

KEY RESULTS: As a nanomaterial, dendrimers have found useful applications as a drug delivery vehicle for antimicrobial agents against biofilm-mediated infections to circumvent these defense mechanisms. The distinctive properties of dendrimers, such as multi-valency, biocompatibility, high water solubility, non-immunogenicity, and biofilm matrix-/cell membrane fusogenicity (ability to merge with intracellular membrane or other proteins), significantly increase the efficacy of antimicrobial agents and reduce the likelihood of recurring infections.

CONCLUSION: This review outlines the current state of dendrimer carriers for biofilm treatments, provides examples of their real-world uses, and examines potential drawbacks.},
}

@article {pmid38720728,
year = {2024},
author = {Abdelrazek, HM and Ghozlan, HA and Sabry, SA and Abouelkheir, SS},
title = {Copper oxide nanoparticles (CuO-NPs) as a key player in the production of oil-based paint against biofilm and other activities.},
journal = {Heliyon},
volume = {10},
number = {9},
pages = {e29758},
pmid = {38720728},
issn = {2405-8440},
abstract = {Copper oxide nanoparticles are among the metal nanoparticles gaining popularity in many biotechnological fields, particularly in marine environments. Their antimicrobial and antibiofilm activities make them appealing to many researchers. Among the various methods of producing nanoparticles, biosynthesis is crucial. Thus, a large number of reports have been made about the microbiological manufacture of these nanoparticles by bacteria. Nevertheless, bio-production by means of the cell-free supernatant of marine bacteria is still in its primary phase. This is landmark research to look at how bacteria make a lot (14 g/L) of copper oxide nanoparticles (CuO-NPs) via the cell-free supernatant of Bacillus siamensis HS, their characterization, and their environmental and medical approaches. The biosynthesized nanoparticles were characterized using a UV-visible spectrum range that provides two maximum absorption peaks, one obtained at 400 nm and the other around 550-600 nm. Diffraction of X-rays (XRD) clarifies that the size of the NPs obtained was estimated to be 18 nm using Debye-Scherrer's equation. Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) displays 91.93 % copper oxide purity. The Transmission Electron Microscope (TEM) image proves that the particles have a spherical form and an average diameter of 6.54-8.60 nm. At the environmental level, nanoparticles incorporated into oil-based paint can be used as antibiofilm tools to diminish the biofilm formed on the submerged surface in the marine environment. In disease management, NPs can be used as a wound healing agent to reduce the wound gap size as well as an anti-tumour agent to control liver cancer cells (hepatoma cells (HepG2)).},
}

@article {pmid38719003,
year = {2024},
author = {Wen, H and Zhang, Y and Mi, Z and Zhang, H and Sun, C and Liu, X and Fan, X},
title = {Rational design of PspAlgL to improve its thermostability and anti-biofilm activity against Pseudomonas aeruginosa.},
journal = {International journal of biological macromolecules},
volume = {269},
number = {Pt 1},
pages = {132084},
doi = {10.1016/j.ijbiomac.2024.132084},
pmid = {38719003},
issn = {1879-0003},
abstract = {Pseudomonas aeruginosa biofilm enhances tolerance to antimicrobials and immune system defenses. Alginate is an important component of biofilm and a virulence factor of P. aeruginosa. The degradation of alginate by alginate lyases has come to serve as an adjunctive therapeutic strategy against P. aeruginosa biofilm, but poor stability of the enzyme limited this application. Thus, PspAlgL, an alginate lyase, can degrade acetylated alginate but has poor thermostability. The 3D structure of PspAlgL was predicted, and the thermostability of PspAlgL was rationally designed by GRAPE strategy, resulting in two variants with better stability. These variants, PspAlgLS270F/E311P and PspAlgLG291S/E311P, effectively degraded the alginate in biofilm. In addition, compared with PspAlgL, these variants were more efficient in inhibiting biofilm formation and degrading the established biofilm of P. aeruginosa PAO1, and they were also able to destroy the biofilm attached to catheters and to increase the sensitivity of P. aeruginosa to the antibiotic amikacin. This study provides one potential anti-biofilm agent for P. aeruginosa infection.},
}

@article {pmid38718953,
year = {2024},
author = {Divya, M and Chen, J and Durán-Lara, EF and Kim, KS and Sekar, V},
title = {Revolutionizing Healthcare: Harnessing Nano Biotechnology with Zinc Oxide Nanoparticles to combat Biofilm and Bacterial Infections-A Short Review.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106679},
doi = {10.1016/j.micpath.2024.106679},
pmid = {38718953},
issn = {1096-1208},
abstract = {A crucial pathogenic mechanism in many bacterial diseases is the ability to create biofilms. Biofilms are suspected to play a role in over 80% of microbial illnesses in humans. In light of the critical requirement for efficient management of bacterial infections, researchers have explored alternative techniques for treating bacterial disorders. One of the most promising ways to address this issue is through the development of long-lasting coatings with antibacterial properties. In recent years, antibacterial treatments based on metallic nanoparticles (NPs) have emerged as an effective strategy in the fight over bacterial drug resistance. Zinc oxide nanoparticles (ZnO-NPs) are the basis of a new composite coating material. This article begins with a brief overview of the mechanisms that underlie bacterial resistance to antimicrobial drugs. A detailed examination of the properties of metallic nanoparticles (NPs) and their potential use as antibacterial drugs for curing drug-sensitive and resistant bacteria follows. Furthermore, we assess metal nanoparticles (NPs) as powerful agents to fight against antibiotic-resistant bacteria and the growth of biofilm, and we look into their potential toxicological effects for the development of future medicines.},
}

@article {pmid38718531,
year = {2024},
author = {Kang, S and Li, Q and Yang, Y and Lan, Y and Wang, X and Jiang, J and Han, M and Zhang, L and Wang, Q and Zhang, W},
title = {Effect of luminescent materials on the aquatic macrophyte Vallisneria natans and periphytic biofilm.},
journal = {Plant physiology and biochemistry : PPB},
volume = {211},
number = {},
pages = {108672},
doi = {10.1016/j.plaphy.2024.108672},
pmid = {38718531},
issn = {1873-2690},
abstract = {Luminescent materials can adjust the spectrum of light energy utilization by plants. However, current research on the effects of luminescent materials on aquatic plants and periphytic biofilms is limited. This study investigated the effects of the luminescent materials 4-(di-p-tolylamino) benzaldehyde-A (DTB-A) and 4-(di-p-tolylamino) benzaldehyde-M (DTB-M) on the submerged macrophyte Vallisneria natans (V. natans) and periphytic biofilm. Result demonstrated that low concentrations of DTB (0.1 μM) significantly promoted the growth and photosynthetic rate of V. natans. In terms of enzyme activity, exposure to a higher concentration of DTB (10 μM) increased the activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT). A combination of DTB-A and DTB-M treatment significantly changed the V. natans morphology and physiological characteristics, reducing the thickness of the cell wall and subsequently, promoting protein accumulation in leaves. There was no difference in the removal of ammonia or phosphate by V. natans at the 0.1 μM concentration, and the removal of ammonia and phosphate by V. natans decreased significantly as the concentration of luminescent material increased. A total of 3563 OTUs were identified in the biofilm community. The microbial community was dominated by Pseudomonas and Fusobacteria. Furthermore, results showed that an obvious decrease in diversity in the DTB-A and DTB-M mixed treatment group. In addition, the migratory aggregation of DTB molecules in plants was observed by fluorescence imaging. Overall, these findings extend our understanding of the mechanism of effect of luminescent materials on submerged macrophytes and their periphytic microorganisms.},
}

@article {pmid38718505,
year = {2024},
author = {Liu, S and Zhang, Z and Zhao, C and Zhang, M and Han, F and Hao, J and Wang, X and Shan, X and Zhou, W},
title = {Nonlinear responses of biofilm bacteria to alkyl-chain length of parabens by DFT calculation.},
journal = {Journal of hazardous materials},
volume = {472},
number = {},
pages = {134460},
doi = {10.1016/j.jhazmat.2024.134460},
pmid = {38718505},
issn = {1873-3336},
abstract = {Parabens can particularly raise significant concerns regarding the disruption of microbial ecology due to their antimicrobial properties. However, the responses of biofilm bacteria to diverse parabens with different alkyl-chain length remains unclear. Here, theoretical calculations and bioinformatic analysis were performed to decipher the influence of parabens varying alkyl-chain lengths on the biofilm bacteria. Our results showed that the disturbances in bacterial community did not linearly response to the alkyl-chain length of parabens, and propylparaben (PrP), with median chain length, had more severe impact on bacterial community. Despite the fact that paraben lethality linearly increased with chain length, the PrP had a higher chemical reactions potential than parabens with shorter or longer alkyl-chain. The chemical reactions potential was critical in the nonlinear responses of bacterial community to alkyl-chain length of parabens. PrP could impose selective pressure to disturb the bacterial community, because it had a more profound contribution to deterministic assembly process. Furthermore, N-acyl-homoserine lactones was also significantly promoted under PrP exposure, confirming that PrP could affect the bacterial community by influencing the quorum-sensing system. Overall, our study reveals the nonlinear responses of bacterial communities to the alkyl-chain lengths of parabens and provides insightful perspectives for the better regulation of parabens. ENVIRONMENTAL IMPLICATION: Parabens are recognized as emerging organic pollutants, which specially raise great concerns due to their antimicrobial properties disturbing microbial ecology. However, few study have addressed the relationship between bacterial community responses and the molecular structural features of parabens with different alkyl-chain length. This investigation revealed nonlinear responses of the bacterial community to the alkyl-chain length of parabens through DFT calculation and bioinformatic analysis and identified the critical roles of chemical reactions potential in nonlinear responses of bacterial community. Our results benefit the precise evaluation of ecological hazards posed by parabens and provide useful insights for better regulation of parabens.},
}

@article {pmid38718417,
year = {2024},
author = {Taşkın Kafa, AH and Aslan, R and Durna Daştan, S and Çeli K, C and Hasbek, M and Emi Noğlu, A},
title = {Molecular diversity of Klebsiella pneumoniae clinical isolates: antimicrobial resistance, virulence, and biofilm formation.},
journal = {Nucleosides, nucleotides & nucleic acids},
volume = {},
number = {},
pages = {1-17},
doi = {10.1080/15257770.2024.2344741},
pmid = {38718417},
issn = {1532-2335},
abstract = {One of the mechanisms responsible for antibiotic resistance in Klebsiella pneumoniae is the enzymes produced by the bacteria; another important mechanism is the ability to form biofilm. In this study, antibiotic resistance, genes associated with virulence, and biofilm-forming properties of K. pneumoniae strains were investigated. A total of 100 K. pneumoniae isolates were obtained from different clinical samples identified by Matrix-Assisted Laser Desorption/Ionization time-of-flight Mass Spectrometry. Antimicrobial susceptibility testing was performed with the Phoenix 100 apparatus. The biofilm forming properties of strains were determined by the microtiter plate method. For molecular analysis, genes encoding the carbapenemase enzyme (blaOXA-48, blaNDM-1, blaIMP, and blaVIM) and biofilm-related genes (treC, luxS, mrkA, and wza) were investigated by polymerase chain reaction (PCR). While 76% of clinical isolates were resistant to three or more antimicrobials, 24% were classified as non-multidrug resistant (non-MDR). When biofilm-forming capacities of clinical isolates were tested, it was determined that the resistant-isolates produced 59.2% strong biofilm, and susceptible-isolates produced 12.5% strong biofilm. According to PCR results, carbapenemase genes were determined as follows: blaOXA-48-70%, blaNDM-49%, and blaKPC-19%, blaOXA-48/blaNDM/blaKPC-12%, blaOXA-48/blaNDM-26%, and blaOXA-48/blaKPC-4%. The biofilm-associated genes in bacterial isolates were determined as follows: luxS-98%, treC-94%, mrkA-88%, and wza-15%. In addition, Hierarchical Clustering Tree and Heatmap analysis revealed an association between isolates that lacks resistance genes and isolates lacks biofilm-formation related genes that were included in MDR or non-MDR classes. As a result, biofilm should be considered in the treatment of MDR infections, and therapy should be planned accordingly. In addition, pursuing the data and genes of antibiotic resistance is significant for combating resistance.},
}

@article {pmid38717992,
year = {2024},
author = {Lencova, S and Stindlova, M and Havlickova, K and Jencova, V and Peroutka, V and Navratilova, K and Zdenkova, K and Stiborova, H and Hauzerova, S and Kostakova, EK and Jankovsky, O and Kejzlar, P and Lukas, D and Demnerova, K},
title = {Influence of Fiber Diameter of Polycaprolactone Nanofibrous Materials on Biofilm Formation and Retention of Bacterial Cells.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.4c03642},
pmid = {38717992},
issn = {1944-8252},
abstract = {To develop microbiologically safe nanofibrous materials, it is crucial to understand their interactions with microbial cells. Current research indicates that the morphology of nanofibers, particularly the diameter of the fibers, may play a significant role in biofilm formation and retention. However, it has not yet been determined how the fiber diameter of poly-ε-caprolactone (PCL), one of the most widely used biopolymers, affects these microbial interactions. In this study, two nanofibrous materials electrospun from PCL (PCL45 and PCL80) with different fiber diameter and characteristic distance δ between fibers were compared in terms of their ability to support or inhibit bacterial biofilm formation and retain bacterial cells. Strains of Escherichia coli (ATCC 25922 and ATCC 8739) and Staphylococcus aureus (ATCC 25923 and ATCC 6538) were used as model bacteria. Biofilm formation rate and retention varied significantly between the E. coli and S. aureus strains (p < 0.05) for the tested nanomaterials. In general, PCL showed a lower tendency to be colonized by the tested bacteria compared to the control material (polystyrene). Fiber diameter did not influence the biofilm formation rate of S. aureus strains and E. coli 25922 (p > 0.05), but it did significantly impact the biofilm formation rate of E. coli 8739 and biofilm morphology formed by all of the tested bacterial strains. In PCL45, thick uniform biofilm layers were formed preferably on the surface, while in PCL80 smaller clusters formed preferably inside the structure. Further, fiber diameter significantly influenced the retention of bacterial cells of all the tested strains (p < 0.001). PCL45, with thin fibers (average fiber diameter of 376 nm), retained up to 7 log (CFU mL[-1]) of staphylococcal cells (100% retention). The overall results indicate PCL45's potential for further research and highlight the nanofibers' morphology influence on bacterial interactions and differences in bacterial strains' behavior in the presence of nanomaterials.},
}

@article {pmid38717096,
year = {2024},
author = {Wang, Z and Zhang, X and Liu, Q and Hu, X and Mei, J and Zhou, J and Zhang, X and Xu, D and Zhu, W and Su, Z and Zhu, C},
title = {Balancing Bioresponsive Biofilm Eradication and Guided Tissue Repair via Pro-Efferocytosis and Bidirectional Pyroptosis Regulation during Implant Surgery.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.4c02157},
pmid = {38717096},
issn = {1936-086X},
abstract = {There is an increasingly growing demand to balance tissue repair guidance and opportunistic infection (OI) inhibition in clinical implant surgery. Herein, we developed a nanoadjuvant for all-stage tissue repair guidance and biofilm-responsive OI eradication via in situ incorporating Cobaltiprotoporphyrin (CoPP) into Prussian blue (PB) to prepare PB-CoPP nanozymes (PCZs). Released CoPP possesses a pro-efferocytosis effect for eliminating apoptotic and progressing necrotic cells in tissue trauma, thus preventing secondary inflammation. Once OIs occur, PCZs with switchable nanocatalytic capacity can achieve bidirectional pyroptosis regulation. Once reaching the acidic biofilm microenvironment, PCZs possess peroxidase (POD)-like activity that can generate reactive oxygen species (ROS) to eradicate bacterial biofilms, especially when synergized with the photothermal effect. Furthermore, generated ROS can promote macrophage pyroptosis to secrete inflammatory cytokines and antimicrobial proteins for biofilm eradication in vivo. After eradicating the biofilm, PCZs possess catalase (CAT)-like activity in a neutral environment, which can scavenge ROS and inhibit macrophage pyroptosis, thereby improving the inflammatory microenvironment. Briefly, PCZs as nanoadjuvants feature the capability of all-stage tissue repair guidance and biofilm-responsive OI inhibition that can be routinely performed in all implant surgeries, providing a wide range of application prospects and commercial translational value.},
}

@article {pmid38717093,
year = {2024},
author = {Hultqvist, LD and Andersen, JB and Nilsson, CM and Jansen, CU and Rybtke, M and Jakobsen, TH and Nielsen, TE and Qvortrup, K and Moser, C and Graz, M and Qvortrup, K and Tolker-Nielsen, T and Givskov, M},
title = {High efficacy treatment of murine Pseudomonas aeruginosa catheter-associated urinary tract infections using the c-di-GMP modulating anti-biofilm compound Disperazol in combination with ciprofloxacin.},
journal = {Antimicrobial agents and chemotherapy},
volume = {},
number = {},
pages = {e0148123},
doi = {10.1128/aac.01481-23},
pmid = {38717093},
issn = {1098-6596},
abstract = {Persistent urinary tract infections (UTIs) in hospitalized patients constitute an important medical problem. It is estimated that 75% of nosocomial UTIs are associated with urinary tract catheters with P. aeruginosa being a species that forms biofilms on these catheters. These infections are highly resistant to standard-of-care antibiotics, and the effects of the host immune defenses, which allows for development of persistent infections. With antibiotics losing their efficacy, new treatment options against resilient infections, such as catheter-associated urinary tract infections (CAUTIs), are critically needed. Central to our anti-biofilm approach is the manipulation of the c-di-GMP signaling pathway in P. aeruginosa to switch bacteria from the protective biofilm to the unprotected planktonic mode of life. We recently identified a compound (H6-335-P1), that stimulates the c-di-GMP degrading activity of the P. aeruginosa BifA protein which plummets the intracellular c-di-GMP content and induces dispersal of P. aeruginosa biofilm bacteria into the planktonic state. In the present study, we formulated H6-335-P1 as a hydrochloride salt (Disperazol), which is water-soluble and facilitates delivery via injection or oral administration. Disperazol can work as a monotherapy, but we observed a 100-fold improvement in efficacy when treating murine P. aeruginosa CAUTIs with a Disperazol/ciprofloxacin combination. Biologically active Disperazol reached the bladder 30 min after oral administration. Our study provides proof of concept that Disperazol can be used in combination with a relevant antibiotic for effective treatment of CAUTIs.},
}

@article {pmid38714243,
year = {2024},
author = {Miranda, ML and Danelon, M and Delbem, ACB and Kopp, W and Nunes, GP and Brighenti, FL},
title = {Enhanced Anti-Biofilm and Anti-Caries Potential of Arginine Combined with Calcium Glycerophosphate and Fluoride.},
journal = {Journal of dentistry},
volume = {},
number = {},
pages = {105039},
doi = {10.1016/j.jdent.2024.105039},
pmid = {38714243},
issn = {1879-176X},
abstract = {OBJECTIVE: The aim of this work was to evaluate the antibiofilm and anticaries properties of the association of arginine (Arg) with calcium glycerophosphate (CaGP) and fluoride (F).

METHODS: An active attachment, polymicrobial biofilm model obtained from saliva and bovine teeth discs were used. After the initial biofilm growth period, the enamel discs were transferred to culture medium. The treatment solutions were added to the culture media to achieve the desired final concentration. The following groups were used: negative control (Control); F (110 ppm F); CaGP (0.05%); Arg (0.8%) and their associations (F+CaGP; Arg+F; Arg+CaGP; Arg+F+CaGP). The following analyses were carried out: bacterial viability (total bacteria, aciduric bacteria and mutans streptococci), pH assessment of the spent culture medium, dry weight quantification, evaluation of surface hardness loss (%SH) and subsurface mineral content. Normality and homoscedasticity were tested (Shapiro-Wilk and Levene's test) and the following tests were applied: two-way ANOVA (acidogenicity), Kruskall-Wallis (microbial viability) and one way ANOVA (dry weight, %SH, mineral content).

RESULTS: The association Arg+F+CaGP resulted in the lowest surface hardness loss in tooth enamel (-10.9±2.3%; p<0.05). Arg+F+CaGP exhibited highest values of subsurface mineral content (10.1±2.9 gHAP/cm[3]) in comparison to Control and F (p<0.05). In comparison to Control and F, Arg+F+CaGP promoted the highest reduction in aciduric bacteria and mutans streptococci (5.7±0.4; 4.4±0.5 logCFU/mL, p<0.05).

CONCLUSIONS: The Arg-F-Ca association demonstrated to be the most effective combination in protecting the loss of surface hardness and subsurface mineral content, in addition to controlling important virulence factors of the cariogenic biofilm.

CLINICAL SIGNIFICANCE: Our findings provide evidence that the Arg-F-Ca association showed an additive effect, particularly concerning protection against enamel demineralization. The combination of these compounds may be a strategy for patients at high risk of caries.},
}

@article {pmid38713935,
year = {2024},
author = {Niu, C and Ying, Y and Zhao, J and Zheng, M and Guo, J and Yuan, Z and Hu, S and Liu, T},
title = {Superior mainstream partial nitritation in an acidic membrane-aerated biofilm reactor.},
journal = {Water research},
volume = {257},
number = {},
pages = {121692},
doi = {10.1016/j.watres.2024.121692},
pmid = {38713935},
issn = {1879-2448},
abstract = {Shortcut nitrogen removal holds significant economic appeal for mainstream wastewater treatment. Nevertheless, it is too difficult to achieve the stable suppression of nitrite-oxidizing bacteria (NOB), and simultaneously maintain the activity of ammonia-oxidizing bacteria (AOB). This study proposes to overcome this challenge by employing the novel acid-tolerant AOB, namely "Candidatus Nitrosoglobus", in a membrane-aerated biofilm reactor (MABR). Superior partial nitritation was demonstrated in low-strength wastewater from two aspects. First, the long-term operation (256 days) under the acidic pH range of 5.0 to 5.2 showed the successful NOB washout by the in situ free nitrous acid (FNA) of approximately 1 mg N/L. This was evidenced by the stable nitrite accumulation ratio (NAR) close to 100 % and the disappearance of NOB shown by 16S rRNA gene amplicon sequencing and fluorescence in situ hybridization. Second, oxygen was sufficiently supplied in the MABR, leading to an unprecedentedly high ammonia oxidation rate (AOR) at 2.4 ± 0.1 kg N/(m[3] d) at a short hydraulic retention time (HRT) of a mere 30 min. Due to the counter diffusion of substrates, the present acidic MABR displayed a significantly higher apparent oxygen affinity (0.36 ± 0.03 mg O2/L), a marginally lower apparent ammonia affinity (14.9 ± 1.9 mg N/L), and a heightened sensitivity to FNA and pH variations, compared with counterparts determined by flocculant acid-tolerant AOB. Beyond supporting the potential application of shortcut nitrogen removal in mainstream wastewater, this study also offers the attractive prospect of intensifying wastewater treatment by markedly reducing the HRT of the aerobic unit.},
}

@article {pmid38711646,
year = {2024},
author = {Lordelo, R and Branco, R and Gama, F and Morais, PV},
title = {Assessment of antimicrobial resistance, biofilm formation, and surface modification potential in hospital strains of Pseudomonas aeruginosa and Klebsiella pneumoniae.},
journal = {Heliyon},
volume = {10},
number = {9},
pages = {e30464},
pmid = {38711646},
issn = {2405-8440},
abstract = {The occurrence of healthcare-associated infections is a multifactorial phenomenon related to hospital space contamination by bacteria. The ESKAPE group, specifically Pseudomonas aeruginosa and Klebsiella pneumoniae, play a relevant role in the occurrence of these infections. Therefore, comprehensive research is needed to identify characteristics that justify the prevalence of these species in the healthcare environment. In this line, the study aimed to determine the antimicrobial resistance, biofilm formation, and the potential for polymer degradation in a collection of 33 P. aeruginosa strains and 2 K. pneumoniae strains sampled from various equipment and non-critical surfaces in a Portuguese hospital. Antimicrobial susceptibility tests revealed that none of the strains was categorized as multidrug-resistant (non-MDR). An assessment of their biofilm-forming capabilities indicated that 97 % of the strains exhibited biofilm-producing characteristics. Notably, within this group, the majority of P. aeruginosa and half of K. pneumoniae strains were classified as strong biofilm producers. Furthermore, the strains were evaluated for their potential to cause damage or change medical devices, namely infusion sets, nasal cannula, and urinary catheters. Three P. aeruginosa strains, two strong and one moderate biofilm producers, showed the highest ability to modify surfaces of the nasal cannula and infusion sets. Additionally, the Chi-square test revealed a statistically significant relationship between the presence of P. aeruginosa strains and the water accession spots. In conclusion, this work suggests that bacteria from this group hold a significant ability to grow in the healthcare environment through the degradation of non-critical materials. This suggests a potential concern for the persistence and proliferation of these organisms in hospital environments, emphasizing the importance of robust infection control measures to mitigate the risks associated with bacterial growth on such surfaces.},
}

@article {pmid38711289,
year = {2024},
author = {Cruz, PD and Wargowsky, R and Gonzalez-Almada, A and Sifontes, EP and Shaykhinurov, E and Jaatinen, K and Jepson, T and Lafleur, JE and Yamane, D and Perkins, J and Pasquale, M and Giang, B and McHarg, M and Falk, Z and McCaffrey, TA},
title = {Blood RNA Biomarkers Identify Bacterial and Biofilm Coinfections in COVID-19 Intensive Care Patients.},
journal = {Journal of intensive care medicine},
volume = {},
number = {},
pages = {8850666241251743},
doi = {10.1177/08850666241251743},
pmid = {38711289},
issn = {1525-1489},
abstract = {Purpose: Secondary opportunistic coinfections are a significant contributor to morbidity and mortality in intensive care unit (ICU) patients, but can be difficult to identify. Presently, new blood RNA biomarkers were tested in ICU patients to diagnose viral, bacterial, and biofilm coinfections. Methods: COVID-19 ICU patients had whole blood drawn in RNA preservative and stored at -80°C. Controls and subclinical infections were also studied. Droplet digital polymerase chain reaction (ddPCR) quantified 6 RNA biomarkers of host neutrophil activation to bacterial (DEFA1), biofilm (alkaline phosphatase [ALPL], IL8RB/CXCR2), and viral infections (IFI27, RSAD2). Viral titer in blood was measured by ddPCR for SARS-CoV2 (SCV2). Results: RNA biomarkers were elevated in ICU patients relative to controls. DEFA1 and ALPL RNA were significantly higher in severe versus incidental/moderate cases. SOFA score was correlated with white blood cell count (0.42), platelet count (-0.41), creatinine (0.38), and lactate dehydrogenase (0.31). ALPL RNA (0.59) showed the best correlation with SOFA score. IFI27 (0.52) and RSAD2 (0.38) were positively correlated with SCV2 viral titer. Overall, 57.8% of COVID-19 patients had a positive RNA biomarker for bacterial or biofilm infection. Conclusions: RNA biomarkers of host neutrophil activation indicate the presence of bacterial and biofilm coinfections in most COVID-19 patients. Recognizing coinfections may help to guide the treatment of ICU patients.},
}

@article {pmid38715287,
year = {2018},
author = {Johani, K and Hu, H and Santos, L and Schiller, S and Deva, AK and Whiteley, G and Almatroudi, A and Vickery, K},
title = {Determination of bacterial species present in biofilm contaminating the channels of clinical endoscopes.},
journal = {Infection, disease & health},
volume = {23},
number = {4},
pages = {189-196},
doi = {10.1016/j.idh.2018.06.003},
pmid = {38715287},
issn = {2468-0869},
abstract = {BACKGROUND: Outbreaks of endoscopy-related Carbapenem-resistant Enterobacteriaceae has highlighted failures in endoscope decontamination resulting in biofilm formation. Biofilms are tolerant to detergents and disinfectants. We evaluated decontaminated endoscope channels for residual bacterial contamination and biofilm presence.

METHODS: 64 channels were collected from 12 gastroscopes and 11 colonoscopes. Aerobic bacteria were isolated from inside the endoscope tubing by scrapping, sonication, and aerobic plate culture. Total number of contaminating bacteria was determined by quantitative real-time PCR with 16s rRNA eubacterial universal primers. Microbial diversity was assessed using next generation DNA sequencing. Biofilm presence was visually confirmed by confocal laser scanning and scanning electron microscopy.

RESULTS: 47% of channels were culture positive, with α-haemolytic Streptococci from gastroscopes and coliforms from colonoscopes the most frequently isolated species. Sphingomonas spp., Staphylococcus spp., Streptococcus spp., and Pseudomonas aeruginosa were also isolated. An average of 1.2 × 10[3] bacteria/cm contaminated air-water channels, 2.8 × 10[2] and 6.6 × 10[2] bacteria/cm contaminated gastroscope and colonoscope working channels, respectively. Biofilm was on all 39 channels examined and was principally composed of environmental bacteria, although all samples contained potential pathogens.

CONCLUSION: Biofilm is present on many endoscope channels obtained from Australian hospitals. Any soil including biofilm can compromise disinfectant action.},
}

@article {pmid38709077,
year = {2024},
author = {Poirier, S and Jean-Pierre, F},
title = {Growing a Cystic Fibrosis-Relevant Polymicrobial Biofilm to Probe Community Phenotypes.},
journal = {Journal of visualized experiments : JoVE},
volume = {},
number = {206},
pages = {},
doi = {10.3791/66785},
pmid = {38709077},
issn = {1940-087X},
mesh = {*Cystic Fibrosis/microbiology ; *Biofilms/growth & development ; Humans ; *Phenotype ; Pseudomonas aeruginosa/physiology ; Staphylococcus aureus/physiology/genetics ; Microbiota/physiology ; Streptococcus sanguis/physiology ; Prevotella melaninogenica/genetics ; },
abstract = {Most in vitro models lack the capacity to fully probe bacterial phenotypes emerging from the complex interactions observed in real-life environments. This is particularly true in the context of hard-to-treat, chronic, and polymicrobial biofilm-based infections detected in the airways of individuals living with cystic fibrosis (CF), a multiorgan genetic disease. While multiple microbiome studies have defined the microbial compositions detected in the airway of people with CF (pwCF), no in vitro models thus far have fully integrated critical CF-relevant lung features. Therefore, a significant knowledge gap exists in the capacity to investigate the mechanisms driving the pathogenesis of mixed species CF lung infections. Here, we describe a recently developed four-species microbial community model, including Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus sanguinis, and Prevotella melaninogenica grown in CF-like conditions. Through the utilization of this system, clinically relevant phenotypes such as antimicrobial recalcitrance of several pathogens were observed and explored at the molecular level. The usefulness of this in vitro model resides in its standardized workflow that can facilitate the study of interspecies interactions in the context of chronic CF lung infections.},
}

*Cystic Fibrosis/microbiology
*Biofilms/growth & development
Humans
*Phenotype
Pseudomonas aeruginosa/physiology
Staphylococcus aureus/physiology/genetics
Microbiota/physiology
Streptococcus sanguis/physiology
Prevotella melaninogenica/genetics

@article {pmid38708178,
year = {2024},
author = {Nafee, N and Gaber, DM and Abouelfetouh, A and Alseqely, M and Empting, M and Schneider, M},
title = {Enzyme-Linked Lipid Nanocarriers for Coping Pseudomonal Pulmonary Infection. Would Nanocarriers Complement Biofilm Disruption or Pave Its Road?.},
journal = {International journal of nanomedicine},
volume = {19},
number = {},
pages = {3861-3890},
pmid = {38708178},
issn = {1178-2013},
mesh = {*Biofilms/drug effects ; *Pseudomonas aeruginosa/drug effects/physiology ; Humans ; *Pseudomonas Infections/drug therapy ; *Nanoparticles/chemistry ; *Chitosan/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry/pharmacokinetics ; Drug Carriers/chemistry ; Cystic Fibrosis/drug therapy/microbiology ; Lipids/chemistry/pharmacology ; Quorum Sensing/drug effects ; A549 Cells ; Alginates/chemistry ; *Liposomes ; },
abstract = {INTRODUCTION: Cystic fibrosis (CF) is associated with pulmonary Pseudomonas aeruginosa infections persistent to antibiotics.

METHODS: To eradicate pseudomonal biofilms, solid lipid nanoparticles (SLNs) loaded with quorum-sensing-inhibitor (QSI, disrupting bacterial crosstalk), coated with chitosan (CS, improving internalization) and immobilized with alginate lyase (AL, destroying alginate biofilms) were developed.

RESULTS: SLNs (140-205 nm) showed prolonged release of QSI with no sign of acute toxicity to A549 and Calu-3 cells. The CS coating improved uptake, whereas immobilized-AL ensured >1.5-fold higher uptake and doubled SLN diffusion across the artificial biofilm sputum model. Respirable microparticles comprising SLNs in carbohydrate matrix elicited aerodynamic diameters MMAD (3.54, 2.48 µm) and fine-particle-fraction FPF (65, 48%) for anionic and cationic SLNs, respectively. The antimicrobial and/or antibiofilm activity of SLNs was explored in Pseudomonas aeruginosa reference mucoid/nonmucoid strains as well as clinical isolates. The full growth inhibition of planktonic bacteria was dependent on SLN type, concentration, growth medium, and strain. OD measurements and live/dead staining proved that anionic SLNs efficiently ceased biofilm formation and eradicated established biofilms, whereas cationic SLNs unexpectedly promoted biofilm progression. AL immobilization increased biofilm vulnerability; instead, CS coating increased biofilm formation confirmed by 3D-time lapse confocal imaging. Incubation of SLNs with mature biofilms of P. aeruginosa isolates increased biofilm density by an average of 1.5-fold. CLSM further confirmed the binding and uptake of the labeled SLNs in P. aeruginosa biofilms. Considerable uptake of CS-coated SLNs in non-mucoid strains could be observed presumably due to interaction of chitosan with LPS glycolipids in the outer cell membrane of P. aeruginosa.

CONCLUSION: The biofilm-destructive potential of QSI/SLNs/AL inhalation is promising for site-specific biofilm-targeted interventional CF therapy. Nevertheless, the intrinsic/extrinsic fundamentals of nanocarrier-biofilm interactions require further investigation.},
}

*Biofilms/drug effects
*Pseudomonas aeruginosa/drug effects/physiology
Humans
*Pseudomonas Infections/drug therapy
*Nanoparticles/chemistry
*Chitosan/chemistry
*Anti-Bacterial Agents/pharmacology/chemistry/pharmacokinetics
Drug Carriers/chemistry
Cystic Fibrosis/drug therapy/microbiology
Lipids/chemistry/pharmacology
Quorum Sensing/drug effects
A549 Cells
Alginates/chemistry
*Liposomes

@article {pmid38706985,
year = {2024},
author = {Huijboom, L and Rashtchi, P and Tempelaars, M and Boeren, S and van der Linden, E and Habibi, M and Abee, T},
title = {Phenotypic and proteomic differences in biofilm formation of two Lactiplantibacillus plantarum strains in static and dynamic flow environments.},
journal = {Biofilm},
volume = {7},
number = {},
pages = {100197},
pmid = {38706985},
issn = {2590-2075},
abstract = {Lactiplantibacillus plantarum is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this study, we compared two strains, WCFS1 and CIP104448, in their ability to produce biofilms in static and dynamic (flow) environments using an in-house designed flow setup. This flow setup enables us to impose a non-uniform flow velocity profile across the well. Biofilm formation occurred at the bottom of the well for both strains, under static and flow conditions, where in the latter condition, CIP104448 also showed increased biofilm formation at the walls of the well in line with the higher hydrophobicity of the cells and the increased initial attachment efficacy compared to WCFS1. Fluorescence and scanning electron microscopy showed open 3D structured biofilms formed under flow conditions, containing live cells and ∼30 % damaged/dead cells for CIP104448, whereas the WCFS1 biofilm showed live cells closely packed together. Comparative proteome analysis revealed minimal changes between planktonic and static biofilm cells of the respective strains suggesting that biofilm formation within 24 h is merely a passive process. Notably, observed proteome changes in WCFS1 and CIP104448 flow biofilm cells indicated similar and unique responses including changes in metabolic activity, redox/electron transfer and cell division proteins for both strains, and myo-inositol production for WCFS1 and oxidative stress response and DNA damage repair for CIP104448 uniquely. Exposure to DNase and protease treatments as well as lethal concentrations of peracetic acid showed highest resistance of flow biofilms. For the latter, CIP104448 flow biofilm even maintained its high disinfectant resistance after dispersal from the bottom and from the walls of the well. Combining all results highlights that L. plantarum biofilm structure and matrix, and physiological state and stress resistance of cells is strain dependent and strongly affected under flow conditions. It is concluded that consideration of effects of flow on biofilm formation is essential to better understand biofilm formation in different settings, including food processing environments.},
}

@article {pmid38706006,
year = {2024},
author = {Liew, KJ and Shahar, S and Shamsir, MS and Shaharuddin, NB and Liang, CH and Chan, KG and Pointing, SB and Sani, RK and Goh, KM},
title = {Integrating multi-platform assembly to recover MAGs from hot spring biofilms: insights into microbial diversity, biofilm formation, and carbohydrate degradation.},
journal = {Environmental microbiome},
volume = {19},
number = {1},
pages = {29},
pmid = {38706006},
issn = {2524-6372},
support = {FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; 4J549//UTM QuickWin grant/ ; 4J549//UTM QuickWin grant/ ; T2EP30123-0028//Singapore Ministry of Education ARC Tier 2 fund/ ; 1736255, 1849206, and 1920954//National Science Foundation/ ; },
abstract = {BACKGROUND: Hot spring biofilms provide a window into the survival strategies of microbial communities in extreme environments and offer potential for biotechnological applications. This study focused on green and brown biofilms thriving on submerged plant litter within the Sungai Klah hot spring in Malaysia, characterised by temperatures of 58-74 °C. Using Illumina shotgun metagenomics and Nanopore ligation sequencing, we investigated the microbial diversity and functional potential of metagenome-assembled genomes (MAGs) with specific focus on biofilm formation, heat stress response, and carbohydrate catabolism.

RESULTS: Leveraging the power of both Illumina short-reads and Nanopore long-reads, we employed an Illumina-Nanopore hybrid assembly approach to construct MAGs with enhanced quality. The dereplication process, facilitated by the dRep tool, validated the efficiency of the hybrid assembly, yielding MAGs that reflected the intricate microbial diversity of these extreme ecosystems. The comprehensive analysis of these MAGs uncovered intriguing insights into the survival strategies of thermophilic taxa in the hot spring biofilms. Moreover, we examined the plant litter degradation potential within the biofilms, shedding light on the participation of diverse microbial taxa in the breakdown of starch, cellulose, and hemicellulose. We highlight that Chloroflexota and Armatimonadota MAGs exhibited a wide array of glycosyl hydrolases targeting various carbohydrate substrates, underscoring their metabolic versatility in utilisation of carbohydrates at elevated temperatures.

CONCLUSIONS: This study advances understanding of microbial ecology on plant litter under elevated temperature by revealing the functional adaptation of MAGs from hot spring biofilms. In addition, our findings highlight potential for biotechnology application through identification of thermophilic lignocellulose-degrading enzymes. By demonstrating the efficiency of hybrid assembly utilising Illumina-Nanopore reads, we highlight the value of combining multiple sequencing methods for a more thorough exploration of complex microbial communities.},
}

@article {pmid38705960,
year = {2024},
author = {Kanwar, K and Sharma, D and Singh, H and Pal, M and Bandhu, R and Azmi, W},
title = {In vitro effects of alginate lyase SG4 + produced by Paenibacillus lautus alone and combined with antibiotics on biofilm formation by mucoid Pseudomonas aeruginosa.},
journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]},
volume = {},
number = {},
pages = {},
pmid = {38705960},
issn = {1678-4405},
abstract = {Alginate is a major extra polymeric substance in the biofilm formed by mucoid Pseudomonas aeruginosa. It is the main proven perpetrator of lung infections in patients suffering from cystic fibrosis. Alginate lyases are very important in the treatment of cystic fibrosis. This study evaluated the role of standalone and in conjugation, effect of alginate lyase of SG4 + isolated from Paenibacillus lautus in enhancing in vitro bactericidal activity of gentamicin and amikacin on mucoid P. aeruginosa. Using Response Surface Methodology (RSM) alginate lyase SG4 + production was optimized in shake flask and there 8.49-fold enhancement in enzyme production. In fermenter, maximum growth (10.15 mg/ml) and alginate lyase (1.46 International Units) production, 1.71-fold was increased using Central Composite Design (CCD). Further, fermentation time was reduced from 48 to 20 h. To the best of our knowledge this is the first report in which CCD was used for fermenter studies to optimize alginate lyase production. The Km and Vmax of purified enzyme were found to be 2.7 mg/ml and 0.84 mol/ml-min, respectively. The half-life (t 1/2) of purified alginate lyase SG4 + at 37 °C was 180 min. Alginate lyase SG4 + in combination with gentamicin and amikacin eradiated 48.4- 52.3% and 58- 64.6%, alginate biofilm formed by P. aeruginosa strains, respectively. The study proves that alginate lyase SG4 + has excellent exopolysaccharide disintegrating ability and may be useful in development of potent therapeutic agent to treat P. aeruginosa biofilms.},
}

@article {pmid38704559,
year = {2024},
author = {Esfandiary, MA and Khosravi, AR and Asadi, S and Nikaein, D and Hassan, J and Sharifzadeh, A},
title = {Antimicrobial and anti-biofilm properties of oleuropein against Escherichia coli and fluconazole-resistant isolates of Candida albicans and Candida glabrata.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {154},
pmid = {38704559},
issn = {1471-2180},
mesh = {*Biofilms/drug effects/growth & development ; *Iridoid Glucosides/pharmacology ; *Microbial Sensitivity Tests ; *Candida glabrata/drug effects/physiology/genetics ; *Candida albicans/drug effects/genetics/physiology ; *Escherichia coli/drug effects/genetics ; *Iridoids/pharmacology ; *Fluconazole/pharmacology ; *Antifungal Agents/pharmacology ; Drug Resistance, Fungal ; Anti-Bacterial Agents/pharmacology ; Microscopy, Electron, Scanning ; },
abstract = {BACKGROUND: Side effects associated with antimicrobial drugs, as well as their high cost, have prompted a search for low-cost herbal medicinal substances with fewer side effects. These substances can be used as supplements to medicine or to strengthen their effects. The current study investigated the effect of oleuropein on the inhibition of fungal and bacterial biofilm in-vitro and at the molecular level.

MATERIALS AND METHODS: In this experimental study, antimicrobial properties were evaluated using microbroth dilution method. The effect of oleuropein on the formation and eradication of biofilm was assessed on 96-well flat bottom microtiter plates and their effects were observed through scanning electron microscopy (SEM). Its effect on key genes (Hwp1, Als3, Epa1, Epa6, LuxS, Pfs) involved in biofilm formation was investigated using the quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) method.

RESULTS: The minimum inhibitory concentration (MIC) and minimum fungicidal/bactericidal concentration (MFC/MBC) for oleuropein were found to be 65 mg/ml and 130 mg/ml, respectively. Oleuropein significantly inhibited biofilm formation at MIC/2 (32.5 mg/ml), MIC/4 (16.25 mg/ml), MIC/8 (8.125 mg/ml) and MIC/16 (4.062 mg/ml) (p < 0.0001). The anti-biofilm effect of oleuropein was confirmed by SEM. RT-qPCR indicated significant down regulation of expression genes involved in biofilm formation in Candida albicans (Hwp1, Als3) and Candida glabrata (Epa1, Epa6) as well as Escherichia coli (LuxS, Pfs) genes after culture with a MIC/2 of oleuropein (p < 0.0001).

CONCLUSIONS: The results indicate that oleuropein has antifungal and antibacterial properties that enable it to inhibit or destroy the formation of fungal and bacterial biofilm.},
}

*Biofilms/drug effects/growth & development
*Iridoid Glucosides/pharmacology
*Microbial Sensitivity Tests
*Candida glabrata/drug effects/physiology/genetics
*Candida albicans/drug effects/genetics/physiology
*Escherichia coli/drug effects/genetics
*Iridoids/pharmacology
*Fluconazole/pharmacology
*Antifungal Agents/pharmacology
Drug Resistance, Fungal
Anti-Bacterial Agents/pharmacology
Microscopy, Electron, Scanning

@article {pmid38703685,
year = {2024},
author = {Wang, H and Zhou, Q},
title = {Bioelectrochemical anaerobic digestion mitigates microplastic pollution and promotes methane recovery of wastewater treatment in biofilm system.},
journal = {Journal of hazardous materials},
volume = {472},
number = {},
pages = {134488},
doi = {10.1016/j.jhazmat.2024.134488},
pmid = {38703685},
issn = {1873-3336},
abstract = {Bioelectrochemical systems (BES) offer significant potential for treating refractory waste and recovering bioenergy. However, their ability to mitigate microplastic pollution in wastewater remains unexplored. This study showed that BES facilitated the treatment of polyethylene (PE), polyvinyl chloride (PVC), and Mix (PE+PVC) microplastic wastewater and the methane recovery (40.61%, 20.02%, 21.19%, respectively). The lactate dehydrogenase (LDH), adenosine triphosphate (ATP), cytochrome c, and nicotinamide adenine dinucleotide (NADH/NAD+) ratios were elevated with electrical stimulation. Moreover, the applied voltage improved the polysaccharides content of the extracellular polymeric substances (EPS) in the PE-BES but decreased in PVC-BES, while the proteins showed the opposite trend. Metatranscriptomic sequencing showed that the abundance of fermentation bacteria, acetogens, electrogens, and methanogens was greatly enhanced by applying voltage, especially at the anode. Methane metabolism was dominated by the acetoclastic methanogenic pathway, with the applied voltage promoting the enrichment of Methanothrix, resulting in the direct conversion of acetate to acetyl-CoA via acetate-CoA ligase (EC: 6.2.1.1), and increased metabolic activity in the anode. Moreover, applied voltage greatly boosted the function genes expression level related to energy metabolism, tricarboxylic acid (TCA) cycle, electron transport, and transporters on the anode biofilm. Overall, these results demonstrate that BES can mitigate microplastic pollution during wastewater treatment.},
}

@article {pmid38703635,
year = {2024},
author = {Kwiecińska-Piróg, J and Chomont, K and Fydrych, D and Stawarz, J and Bogiel, T and Przekwas, J and Gospodarek-Komkowska, E},
title = {How xylitol, gluten, and lactose change human gut microbiota Escherichia coli and Lactobacillus rhamnosus GG biofilm.},
journal = {Nutrition (Burbank, Los Angeles County, Calif.)},
volume = {124},
number = {},
pages = {112446},
doi = {10.1016/j.nut.2024.112446},
pmid = {38703635},
issn = {1873-1244},
abstract = {OBJECTIVE: The human gut microbiota is composed of many viruses, bacteria, and fungi. Escherichia coli representatives are facultative anaerobic bacteria in the colon that play a crucial role in the metabolism of lactose, vitamin synthesis, and immune system modulation. E. coli forms a biofilm on the epithelial cell surface of the intestine that can be modified by diet compounds, i.e., gluten, xylitol, lactose, and probiotics.

METHODS: In the present study, the impact of probiotic-derived Lactobacillus rhamnosus GG strain on non-pathogenic E. coli biofilm was examined. The mono- and multispecies biofilm was also treated with gluten, xylitol, and lactose. We used 96-well plates to obtain biofilm growth. Biofilm was stained using crystal violet. To evaluate the type of interaction in mono- and multispecies biofilm, a new formula was introduced: biofilm interaction ratio index (BIRI). To describe the impact of nutrients on biofilm formation, the biofilm formation impact ratio (BFIR) was calculated.

RESULTS: The biofilms formed by both examined species are stronger than in monocultures. All the BIRI values were above 3.0. It was found that the monospecies biofilm of L. rhamnosus is strongly inhibited by gluten (84.5%) and the monospecies biofilm of E. coli by xylitol (85.5%). The mixed biofilm is inhibited by lactose (78.8%) and gluten (90.6%).

CONCLUSION: The relations between bacteria in the mixed biofilm led to changes in biofilm formation by E. coli and L. rhamnosus GG. Probiotics might be helpful in rebuilding the gut microbiota after broad spectrum antibiotic therapy, but only if gluten and lactose are excluded from diet.},
}

@article {pmid38702839,
year = {2024},
author = {Paulino, S and Petek, S and le Strat, Y and Bourgougnon, N and Le Blay, G},
title = {Cultivable epiphytic bacteria of the Chlorophyta Ulva sp. : diversity, antibacterial and biofilm-modulating activities.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jambio/lxae099},
pmid = {38702839},
issn = {1365-2672},
abstract = {AIMS: Macroalgae harbor a rich epiphytic microbiota that plays a crucial role in algal morphogenesis and defense mechanisms. This study aims to isolate epiphytic cultivable microbiota from Ulva sp. surfaces. Various culture media were employed to evaluate a wide range of cultivable microbiota. Our objective was to assess the antibacterial and biofilm-modulating activities of supernatants from isolated bacteria.

METHODS AND RESULTS: 69 bacterial isolates from Ulva sp. were identified based on 16S rRNA gene sequencing. Their antibacterial activity and biofilm modulation potential were screened against three target marine bacteria : 45%, mostly affiliated with Gammaproteobacteria and mainly grown on diluted R2A medium (R2Ad), showed strong antibacterial activity while 18% had a significant impact on biofilm modulation. Molecular network analysis was carried out on four bioactive bacterial supernatants, revealing new molecules potentially responsible for their activities.

CONCLUSION: R2Ad offered the greatest diversity and proportion of active isolates. The molecular network approach holds promise for both identifying bacterial isolates based on their molecular production and characterizing antibacterial and biofilm-modulating activities.},
}

@article {pmid38702622,
year = {2024},
author = {Alabssawy, AN and Abu-Elghait, M and Azab, AM and Khalaf-Allah, HMM and Ashry, AS and Ali, AOM and Sabra, AAA and Salem, SS},
title = {Hindering the biofilm of microbial pathogens and cancer cell lines development using silver nanoparticles synthesized by epidermal mucus proteins from Clarias gariepinus.},
journal = {BMC biotechnology},
volume = {24},
number = {1},
pages = {28},
pmid = {38702622},
issn = {1472-6750},
mesh = {*Metal Nanoparticles/chemistry ; *Biofilms/drug effects/growth & development ; *Silver/chemistry/pharmacology ; Animals ; Humans ; *Catfishes ; Mucus/metabolism ; Antineoplastic Agents/pharmacology/chemistry ; Vero Cells ; Fish Proteins/pharmacology/chemistry/metabolism ; Chlorocebus aethiops ; Cell Line, Tumor ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa/drug effects ; Anti-Infective Agents/pharmacology/chemistry ; Staphylococcus aureus/drug effects/physiology ; Candida albicans/drug effects ; Epidermis/metabolism ; },
abstract = {Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV-vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200-6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines.},
}

*Metal Nanoparticles/chemistry
*Biofilms/drug effects/growth & development
*Silver/chemistry/pharmacology
Animals
Humans
*Catfishes
Mucus/metabolism
Antineoplastic Agents/pharmacology/chemistry
Vero Cells
Fish Proteins/pharmacology/chemistry/metabolism
Chlorocebus aethiops
Cell Line, Tumor
Microbial Sensitivity Tests
Pseudomonas aeruginosa/drug effects
Anti-Infective Agents/pharmacology/chemistry
Staphylococcus aureus/drug effects/physiology
Candida albicans/drug effects
Epidermis/metabolism

@article {pmid38702575,
year = {2024},
author = {Pandey, P and Vavilala, SL},
title = {From Gene Editing to Biofilm Busting: CRISPR-CAS9 Against Antibiotic Resistance-A Review.},
journal = {Cell biochemistry and biophysics},
volume = {},
number = {},
pages = {},
pmid = {38702575},
issn = {1559-0283},
abstract = {In recent decades, the development of novel antimicrobials has significantly slowed due to the emergence of antimicrobial resistance (AMR), intensifying the global struggle against infectious diseases. Microbial populations worldwide rapidly develop resistance due to the widespread use of antibiotics, primarily targeting drug-resistant germs. A prominent manifestation of this resistance is the formation of biofilms, where bacteria create protective layers using signaling pathways such as quorum sensing. In response to this challenge, the CRISPR-Cas9 method has emerged as a ground-breaking strategy to counter biofilms. Initially identified as the "adaptive immune system" of bacteria, CRISPR-Cas9 has evolved into a state-of-the-art genetic engineering tool. Its exceptional precision in altering specific genes across diverse microorganisms positions it as a promising alternative for addressing antibiotic resistance by selectively modifying genes in diverse microorganisms. This comprehensive review concentrates on the historical background, discovery, developmental stages, and distinct components of CRISPR Cas9 technology. Emphasizing its role as a widely used genome engineering tool, the review explores how CRISPR Cas9 can significantly contribute to the targeted disruption of genes responsible for biofilm formation, highlighting its pivotal role in reshaping strategies to combat antibiotic resistance and mitigate the challenges posed by biofilm-associated infectious diseases.},
}

@article {pmid38701663,
year = {2024},
author = {Zibar Belasic, T and Badnjevic, M and Zigante, M and Mohar Vitezic, B and Spalj, S and Markova-Car, EP},
title = {Supragingival dental biofilm profile and biofilm control during orthodontic treatment with fixed orthodontic appliance: A randomized controlled trial.},
journal = {Archives of oral biology},
volume = {164},
number = {},
pages = {105984},
doi = {10.1016/j.archoralbio.2024.105984},
pmid = {38701663},
issn = {1879-1506},
abstract = {OBJECTIVE: The effectiveness of supragingival dental biofilm control during orthodontic treatment and changes in the bacterial profile were analyzed.

DESIGN: Sixty-four participants aged 12-22 years (57% female) were included in the study. Participants underwent orthodontic treatment with fixed appliances and were randomly assigned to one of the three groups, which during a period of one month: (I) used chlorhexidine digluconate (CHX), (II) used high concentration of fluoride (F) gel and (III) performed standard oral hygiene. The plaque and gingivitis index, pH of biofilm and white spot lesions (WSL) were assessed. Changes of the bacteria in the biofilm were analyzed by the quantitative polymerase chain reaction RESULTS: Increase in the plaque index, pH of biofilm, and WSL was observed during orthodontic treatment with standard oral hygiene. Large interindividual variability was present, and the effects of one-month use of fluorides and CHX on clinical parameters were not significant. Despite standard hygiene the abundance of studied biofilm bacteria increased - the most Streptoccocus mutans (14.2x) and S. salivarius (3.3x), moderate Veillonella parvula (3x) and the least S. sobrinus (2.3x) and Agregatibacter actinomycetemcomitans (1.9x). The use of CHX reduced S. sobrinus (2.2x) and A. actinomycetemcomitans (1.9x). Fluoride use reduced A. actinomycetemcomitans (1.3x) and S. sobrinus (1.2x). Fluorides better controlled S. mutans than CHX.

CONCLUSION: Bacterial biomass in supragingival biofilm increased during treatment with metal orthodontic appliances, with greater increase in cariogenic bacteria than periopathogens. Fluoride controlled S. mutans, while CHX S. sobrinus and A. actinomycetemcomitans.},
}

@article {pmid38700735,
year = {2024},
author = {Polat, T and Soyhan, İ and Cebeci, S and İldeniz, TAÖ and Gök, Ö and Elmas, MA and Mozioğlu, E and Ünübol, N},
title = {New-generation biofilm effective antimicrobial peptides and a real-time anti-biofilm activity assay: CoMIC.},
journal = {Applied microbiology and biotechnology},
volume = {108},
number = {1},
pages = {316},
pmid = {38700735},
issn = {1432-0614},
mesh = {*Biofilms/drug effects ; *Antimicrobial Peptides/pharmacology/chemistry ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology/chemistry ; Models, Molecular ; Microscopy, Electron, Scanning ; Bacteria/drug effects ; },
abstract = {Nowadays, it is very important to produce new-generation drugs with antimicrobial properties that will target biofilm-induced infections. The first target for combating these microorganisms, which are the source itself. Antimicrobial peptides, which are more effective than antibiotics due to their ability to kill microorganisms and use a different metabolic pathway, are among the new options today. The aim of this study is to develop new-generation antibiotics that inhibit both biofilm-producing bacteria and the biofilm itself. For this purpose, we designed four different peptides by combining two amino acid forms (D- and L-) with the same sequence having alpha helix structures. It was found that the combined use of these two forms can increase antimicrobial efficacy more than 30-fold. These results are supported by molecular modeling and scanning electron microscopy (SEM), at the same time cytotoxicity (IC50) and hemotoxicity (HC50) values remained within the safe range. Furthermore, antibiofilm activities of these peptides were investigated. Since the existing biofilm inhibition methods in the literature do not technically simulate the exact situation, in this study, we have developed a real-time observable biofilm model and a new detection method based on it, which we call the CoMIC method. Findings have shown that the NET1 peptide with D-leucine amino acid in its structure and the NET3 peptide with D-arginine amino acid in its structure are effective in inhibiting biofilm. As a conclusion, our peptides can be considered as potential next-generation broad-spectrum antibiotic molecule/drug candidates that might be used in biofilm and clinical important bacteria. KEY POINTS: • Antimicrobial peptides were developed to inhibit both biofilms producing bacteria and the biofilm itself. • CoMIC will fill a very crucial gap in understanding biofilms and conducting the necessary quantitative studies. • Molecular modelling studies, NET1 peptide molecules tends to move towards and adhere to the membrane within nanoseconds.},
}

*Biofilms/drug effects
*Antimicrobial Peptides/pharmacology/chemistry
*Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology/chemistry
Models, Molecular
Microscopy, Electron, Scanning
Bacteria/drug effects

@article {pmid38700325,
year = {2024},
author = {Liu, X and Lertsethtakarn, P and Mariscal, VT and Yildiz, F and Ottemann, KM},
title = {Counterclockwise rotation of the flagellum promotes biofilm initiation in Helicobacter pylori.},
journal = {mBio},
volume = {},
number = {},
pages = {e0044024},
doi = {10.1128/mbio.00440-24},
pmid = {38700325},
issn = {2150-7511},
abstract = {UNLABELLED: Motility promotes biofilm initiation during the early steps of this process: microbial surface association and attachment. Motility is controlled in part by chemotaxis signaling, so it seems reasonable that chemotaxis may also affect biofilm formation. There is a gap, however, in our understanding of the interactions between chemotaxis and biofilm formation, partly because most studies analyzed the phenotype of only a single chemotaxis signaling mutant, e.g., cheA. Here, we addressed the role of chemotaxis in biofilm formation using a full set of chemotaxis signaling mutants in Helicobacter pylori, a class I carcinogen that infects more than half the world's population and forms biofilms. Using mutants that lack each chemotaxis signaling protein, we found that chemotaxis signaling affected the biofilm initiation stage, but not mature biofilm formation. Surprisingly, some chemotaxis mutants elevated biofilm initiation, while others inhibited it in a manner that was not tied to chemotaxis ability or ligand input. Instead, the biofilm phenotype correlated with flagellar rotational bias. Specifically, mutants with a counterclockwise bias promoted biofilm initiation, e.g., ∆cheA, ∆cheW, or ∆cheV1; in contrast, those with a clockwise bias inhibited it, e.g., ∆cheZ, ∆chePep, or ∆cheV3. We tested this correlation using a counterclockwise bias-locked flagellum, which induced biofilm formation independent of the chemotaxis system. These CCW flagella, however, were not sufficient to induce biofilm formation, suggesting there are downstream players. Overall, our work highlights the new finding that flagellar rotational direction promotes biofilm initiation, with the chemotaxis signaling system operating as one mechanism to control flagellar rotation.

IMPORTANCE: Chemotaxis signaling systems have been reported to contribute to biofilm formation in many bacteria; however, how they regulate biofilm formation remains largely unknown. Chemotaxis systems are composed of many distinct kinds of proteins, but most previous work analyzed the biofilm effect of loss of only a few. Here, we explored chemotaxis' role during biofilm formation in the human-associated pathogenic bacterium Helicobacter pylori. We found that chemotaxis proteins are involved in biofilm initiation in a manner that correlated with how they affected flagellar rotation. Biofilm initiation was high in mutants with counterclockwise (CCW) flagellar bias and low in those with clockwise bias. We supported the idea that a major driver of biofilm formation is flagellar rotational direction using a CCW-locked flagellar mutant, which stays CCW independent of chemotaxis input and showed elevated biofilm initiation. Our data suggest that CCW-rotating flagella, independent of chemotaxis inputs, are a biofilm-promoting signal.},
}

@article {pmid38698252,
year = {2024},
author = {Berto, LA and Ettmayer, JB and Stutzer, D and Nietzsche, S and Niederhauser, T and Burger, J and Sculean, A and Eick, S and Hofmann, M},
title = {In-vitro effects of novel periodontal scalers with a planar ultrasonic piezoelectric transducer on periodontal biofilm removal, dentine surface roughness, and periodontal ligament fibroblasts adhesion.},
journal = {Clinical oral investigations},
volume = {28},
number = {5},
pages = {294},
pmid = {38698252},
issn = {1436-3771},
mesh = {*Biofilms ; *Fibroblasts ; Humans ; *Surface Properties ; *Titanium ; *Dental Scaling/instrumentation ; In Vitro Techniques ; *Dentin/microbiology ; *Periodontal Ligament/cytology ; Transducers ; Cell Adhesion ; Stainless Steel ; Equipment Design ; Ultrasonic Therapy/instrumentation ; },
abstract = {OBJECTIVES: To compare ultrasonic scaler prototypes based on a planar piezoelectric transducer with different working frequencies featuring a titanium (Ti-20, Ti-28, and Ti-40) or stainless steel (SS-28) instrument, with a commercially available scaler (com-29) in terms of biofilm removal and reformation, dentine surface roughness and adhesion of periodontal fibroblasts.

MATERIALS AND METHODS: A periodontal multi-species biofilm was formed on specimens with dentine slices. Thereafter specimens were instrumented with scalers in a periodontal pocket model or left untreated (control). The remaining biofilms were quantified and allowed to reform on instrumented dentine slices. In addition, fibroblasts were seeded for attachment evaluation after 72 h of incubation. Dentine surface roughness was analyzed before and after instrumentation.

RESULTS: All tested instruments reduced the colony-forming unit (cfu) counts by about 3 to 4 log10 and the biofilm quantity (each p < 0.01 vs. control), but with no statistically significant difference between the instrumented groups. After 24-hour biofilm reformation, no differences in cfu counts were observed between any groups, but the biofilm quantity was about 50% in all instrumented groups compared to the control. The attachment of fibroblasts on instrumented dentine was significantly higher than on untreated dentine (p < 0.05), with the exception of Ti-20. The dentine surface roughness was not affected by any instrumentation.

CONCLUSIONS: The planar piezoelectric scaler prototypes are able to efficiently remove biofilm without dentine surface alterations, regardless of the operating frequency or instrument material.

CLINICAL RELEVANCE: Ultrasonic scalers based on a planar piezoelectric transducer might be an alternative to currently available ultrasonic scalers.},
}

*Biofilms
*Fibroblasts
Humans
*Surface Properties
*Titanium
*Dental Scaling/instrumentation
In Vitro Techniques
*Dentin/microbiology
*Periodontal Ligament/cytology
Transducers
Cell Adhesion
Stainless Steel
Equipment Design
Ultrasonic Therapy/instrumentation

@article {pmid38695568,
year = {2024},
author = {Kaplan, JB and Horswill, AR},
title = {Micrococcal nuclease regulates biofilm formation and dispersal in methicillin-resistant Staphylococcus aureus USA300.},
journal = {mSphere},
volume = {},
number = {},
pages = {e0012624},
doi = {10.1128/msphere.00126-24},
pmid = {38695568},
issn = {2379-5042},
abstract = {Biofilm formation is an important virulence factor for methicillin-resistant Staphylococcus aureus (MRSA). The extracellular matrix of MRSA biofilms contains significant amounts of double-stranded DNA that hold the biofilm together. MRSA cells secrete micrococcal nuclease (Nuc1), which degrades double-stranded DNA. In this study, we used standard methodologies to investigate the role of Nuc1 in MRSA biofilm formation and dispersal. We quantified biofilm formation and extracellular DNA (eDNA) levels in broth and agar cultures. In some experiments, cultures were supplemented with sub-MIC amoxicillin to induce biofilm formation. Biofilm erosion was quantitated by culturing biofilms on rods and enumerating detached colony-forming units (CFUs), and biofilm sloughing was investigated by perfusing biofilms cultured in glass tubes with fresh broth and measuring the sizes of the detached cell aggregates. We found that an MRSA nuc1[-] mutant strain produced significantly more biofilm and more eDNA than a wild-type strain, both in the absence and presence of sub-MIC amoxicillin. nuc1[-] mutant biofilms grown on rods detached significantly less than wild-type biofilms. Detachment was restored by exogenous DNase or complementing the nuc1[-] mutant. In the sloughing assay, nuc1[-] mutant biofilms released cell aggregates that were significantly larger than those released by wild-type biofilms. Our results suggest that Nuc1 modulates biofilm formation, biofilm detachment, and the sizes of detached cell aggregates. These processes may play a role in the spread and subsequent survival of MRSA biofilms during biofilm-related infections.IMPORTANCEInfections caused by antibiotic-resistant bacteria known as methicillin-resistant Staphylococcus aureus (MRSA) are a significant problem in hospitals. MRSA forms adherent biofilms on implanted medical devices such as catheters and breathing tubes. Bacteria can detach from biofilms on these devices and spread to other parts of the body such as the blood or lungs, where they can cause life-threatening infections. In this article, researchers show that MRSA secretes an enzyme known as thermonuclease that causes bacteria to detach from the biofilm. This is important because understanding the mechanism by which MRSA detaches from biofilms could lead to the development of procedures to mitigate the problem.},
}

@article {pmid38695444,
year = {2024},
author = {Dos Santos, ACM and Mendes, FSF and Pompeo, FT and Watanabe, E and Macedo, AP and de Souza, VOP and Paranhos, HFO and Silva-Lovato, CH},
title = {Effectiveness of experimental dentifrices based on essential oils on biofilm on complete dentures: an in vitro study.},
journal = {Journal of applied oral science : revista FOB},
volume = {32},
number = {},
pages = {e20230397},
doi = {10.1590/1678-7757-2023-0397},
pmid = {38695444},
issn = {1678-7765},
mesh = {*Biofilms/drug effects ; *Dentifrices/pharmacology/chemistry ; *Oils, Volatile/pharmacology/chemistry ; *Denture, Complete/microbiology ; *Materials Testing ; Time Factors ; Reproducibility of Results ; Toothbrushing ; Colony Count, Microbial ; Staphylococcus aureus/drug effects ; Statistics, Nonparametric ; Streptococcus mutans/drug effects ; Analysis of Variance ; Microbial Viability/drug effects ; Candida albicans/drug effects ; Reference Values ; Acrylic Resins/chemistry/pharmacology ; },
abstract = {UNLABELLED: Specific products containing natural resources can contribute to the innovation of complete denture hygiene.

OBJECTIVE: To conduct an in vitro evaluation of experimental dentifrices containing essential oils of Bowdichia virgilioides Kunth (BvK), Copaifera officinalis (Co), Eucalyptus citriodora (Ec), Melaleuca alternifolia (Ma) and Pinus strobus (Ps) at 1%.

METHODOLOGY: The variables evaluated were organoleptic and physicochemical characteristics, abrasiveness (mechanical brushing machine) simulating 2.5 years, and microbial load (Colony Forming Units - CFU/mL), metabolic activity (XTT assay) and cell viability (Live/Dead® BacLight™ kit) of the multispecies biofilm (Streptococcus mutans: Sm, Staphylococcus aureus: Sa, Candida albicans: Ca and Candida glabrata: Cg). Specimens of heat-polymerized acrylic resins (n=256) (n=96 specimens for abrasiveness, n=72 for microbial load count, n=72 for biofilm metabolic activity, n=16 for cell viability and total biofilm quantification) with formed biofilm were divided into eight groups for manual brushing (20 seconds) with a dental brush and distilled water (NC: negative control), Trihydral (PC: positive control), placebo (Pl), BvK, Co, Ec, Ma or Ps. After brushing, the specimens were washed with PBS and immersed in Letheen Broth medium, and the suspension was sown in solid specific medium. The organoleptic characteristics were presented by descriptive analysis. The values of density, pH, consistency and viscosity were presented in a table. The data were analyzed with the Wald test in a generalized linear model, followed by the Kruskal-Wallis test, Dunn's test (mass change) and the Bonferroni test (UFC and XTT). The Wald test in Generalized Estimating Equations and the Bonferroni test were used to analyze cell viability.

RESULTS: All dentifrices showed stable organoleptic characteristics and adequate physicochemical properties. CN, Ec, Ps, Pl and PC showed low abrasiveness. There was a significant difference between the groups (p<0.001) for microbial load, metabolic activity and biofilm viability.

CONCLUSIONS: It was concluded that the BvK, Ec and Ps dentifrices are useful for cleaning complete dentures, as they have antimicrobial activity against biofilm. The dentifrices containing Bowdichia virgilioides Kunth showed medium abrasiveness and should be used with caution.},
}

*Biofilms/drug effects
*Dentifrices/pharmacology/chemistry
*Oils, Volatile/pharmacology/chemistry
*Denture, Complete/microbiology
*Materials Testing
Time Factors
Reproducibility of Results
Toothbrushing
Colony Count, Microbial
Staphylococcus aureus/drug effects
Statistics, Nonparametric
Streptococcus mutans/drug effects
Analysis of Variance
Microbial Viability/drug effects
Candida albicans/drug effects
Reference Values
Acrylic Resins/chemistry/pharmacology

@article {pmid38695072,
year = {2024},
author = {Søborg, DA and Højris, B and Brinkmann, K and Pedersen, MR and Skovhus, TL},
title = {Characterizing the development of biofilm in polyethylene pipes in the non-chlorinated Danish drinking-water distribution system.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-18},
doi = {10.1080/08927014.2024.2343839},
pmid = {38695072},
issn = {1029-2454},
abstract = {In newly commissioned drinking-water polyethylene (PE) pipes, biofilm develops on the inner pipe surface. The microbial community composition from colonization to the establishment of mature biofilms is less known, including the effect on the distributed water quality. Biofilm development was followed through 1.5 years in PE-pipe side streams at two locations of a full-scale, non-chlorinated drinking-water distribution system (leaving a waterworks versus 5-6 km from a waterworks) along with inlet and outlet water quality. Mature biofilms were established after ∼8-9 months, dominated by Proteobacteria, Actinobacteria and Saccharibacteria (61-93% relative abundance), with a higher diversity (OTUs/Shannon Index/16S rRNA gene amplicon sequencing) in pipes in the far end of the distribution system. Comamonadaceae, and specifically Aquabacterium (>30% of reads), dominated young (∼1.5-month-old) biofilms. Young biofilms were linked to increased microbiological counts in drinking water (HPC/ATP/qPCR), while the establishment of mature biofilms led to a drop in HPC and benefited the water quality, highlighting the importance of optimizing commissioning procedures for rapidly achieving mature and stable biofilms.},
}

@article {pmid38694801,
year = {2024},
author = {Zhou, X and Liu, H and Fan, X and Xu, X and Gao, Y and Bi, X and Cheng, L and Huang, S and Zhao, F and Yang, T},
title = {Innovative inbuilt moving bed biofilm reactor for nitrogen removal applied in household aquarium.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1373119},
doi = {10.3389/fmicb.2024.1373119},
pmid = {38694801},
issn = {1664-302X},
abstract = {An innovative inbuilt moving bed biofilm reactor (MBBR) was created to protect fish from nitrogen in a household aquarium. During the 90 experimental days, the ammonia nitrogen (NH4[+]-N) concentration in the aquarium with the inbuilt MBBR was always below 0.5 mg/L, which would not threaten the fish. Concurrently, nitrite and nitrate nitrogen concentrations were always below 0.05 mg/L and 4.5 mg/L, respectively. However, the blank contrast aquarium accumulated 1.985 mg/L NH4[+]-N on the 16th day, which caused the fish to die. The suspended biofilms could achieve the specific NH4[+]-N removal rate of 45.43 g/m[3]/d. Biofilms presented sparsely with filamentous structures and showed certain degrees of roughness. The bacterial communities of the suspended biofilms and the sediment were statistically different (p < 0.05), reflected in denitrifying and nitrifying bacteria. In particular, the relative abundance of Nitrospira reached 1.4%, while the genus was barely found in sediments. The suspended biofilms showed potentials for nitrification function with the predicted sequence numbers of ammonia monooxygenase [1.14.99.39] and hydroxylamine dehydrogenase [EC:1.7.2.6] of 220 and 221, while the values of the sediment were only 5 and 1. This study created an efficient NH4[+]-N removal inbuilt MBBR for household aquariums and explored its mechanism to afford a basis for its utilization.},
}

@article {pmid38693842,
year = {2024},
author = {Meng, Y and Chen, S and Wang, C and Ni, X},
title = {Advances in Composite Biofilm Biomimetic Nanodrug Delivery Systems for Cancer Treatment.},
journal = {Technology in cancer research & treatment},
volume = {23},
number = {},
pages = {15330338241250244},
doi = {10.1177/15330338241250244},
pmid = {38693842},
issn = {1533-0338},
mesh = {Humans ; *Neoplasms/drug therapy ; *Biofilms/drug effects ; *Drug Delivery Systems ; *Biomimetics/methods ; *Antineoplastic Agents/administration & dosage/pharmacology ; Biomimetic Materials/chemistry ; Animals ; Drug Carriers/chemistry ; },
abstract = {Single biofilm biomimetic nanodrug delivery systems based on single cell membranes, such as erythrocytes and cancer cells, have immune evasion ability, good biocompatibility, prolonged blood circulation, and high tumor targeting. Because of the different characteristics and functions of each single cell membrane, more researchers are using various hybrid cell membranes according to their specific needs. This review focuses on several different types of biomimetic nanodrug-delivery systems based on composite biofilms and looks forward to the challenges and possible development directions of biomimetic nanodrug-delivery systems based on composite biofilms to provide reference and ideas for future research.},
}

Humans
*Neoplasms/drug therapy
*Biofilms/drug effects
*Drug Delivery Systems
*Biomimetics/methods
*Antineoplastic Agents/administration & dosage/pharmacology
Biomimetic Materials/chemistry
Animals
Drug Carriers/chemistry

@article {pmid38692363,
year = {2024},
author = {Zhang, X and Zhao, Y and Wang, Y and Qian, H and Xing, J and Joseph, A and Rene, ER and Li, J and Zhu, N},
title = {The interplay of hematite and photic biofilm triggers acceleration of biotic nitrate removal.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {142136},
doi = {10.1016/j.chemosphere.2024.142136},
pmid = {38692363},
issn = {1879-1298},
abstract = {The soil-water interface is replete with photic biofilm and iron minerals; however, the potential of how iron minerals promote biotic nitrate removal is still unknown. This study investigates the physiological and ecological responses of photic biofilm to hematite (Fe2O3), in order to explore a practically feasible approach for in-situ nitrate removal. The nitrate removal rate of photic biofilm was significantly higher in the presence of Fe2O3 (92.5%) compared to the control (82.8%). Results show that the presence of Fe2O3 changed the community composition of photic biofilm, facilitates the thriving of Magnetospirillum and Pseudomonas, and promotes the growth of photic biofilm represented by the extracellular polymeric substance (EPS) and the content of chlorophyll. The presence of Fe2O3 also induces oxidative stress (•O2[-]) in photic biofilm, which was demonstrated by electron spin resonance spectrometry. However, the photic biofilm could improve the EPS productivity to prevent the entrance of Fe2O3 to cells in the biofilm matrix and mitigate oxidative stress. The Fe2O3 then promoted the relative abundance of Magnetospirillum and Pseudomonas and the activity of nitrate reductase, which accelerates nitrate reduction by photic biofilm. This study provides an insight into the interaction between iron minerals and photic biofilm and demonstrates the possibility of combining biotic and abiotic methods to improve the in-situ nitrate removal rate.},
}

@article {pmid38690364,
year = {2024},
author = {Meliefste, HM and Mudde, SE and Ammerman, NC and de Steenwinkel, JEM and Bax, HI},
title = {A laboratory perspective on Mycobacterium abscessus biofilm culture, characterization and drug activity testing.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1392606},
pmid = {38690364},
issn = {1664-302X},
abstract = {Mycobacterium abscessus is an emerging opportunistic pathogen causing severe pulmonary infections in patients with underlying lung disease and cystic fibrosis in particular. The rising prevalence of M. abscessus infections poses an alarming threat, as the success rates of available treatment options are limited. Central to this challenge is the absence of preclinical in vitro models that accurately mimic in vivo conditions and that can reliably predict treatment outcomes in patients. M. abscessus is notorious for its association with biofilm formation within the lung. Bacteria in biofilms are more recalcitrant to antibiotic treatment compared to planktonic bacteria, which likely contributes to the lack of correlation between preclinical drug activity testing (typically performed on planktonic bacteria) and treatment outcome. In recent years, there has been a growing interest in M. abscessus biofilm research. However, the absence of standardized methods for biofilm culture, biofilm characterization and drug activity testing has led to a wide spectrum of, sometimes inconsistent, findings across various studies. Factors such as strain selection, culture medium, and incubation time hugely impact biofilm development, phenotypical characteristics and antibiotic susceptibility. Additionally, a broad range of techniques are used to study M. abscessus biofilms, including quantification of colony-forming units, crystal violet staining and fluorescence microscopy. Yet, limitations of these techniques and the selected readouts for analysis affect study outcomes. Currently, research on the activity of conventional antibiotics, such as clarithromycin and amikacin, against M. abscessus biofilms yield ambiguous results, underscoring the substantial impact of experimental conditions on drug activity assessment. Beyond traditional drug activity testing, the exploration of novel anti-biofilm compounds and the improvement of in vitro biofilm models are ongoing. In this review, we outline the laboratory models, experimental variables and techniques that are used to study M. abscessus biofilms. We elaborate on the current insights of M. abscessus biofilm characteristics and describe the present understanding of the activity of traditional antibiotics, as well as potential novel compounds, against M. abscessus biofilms. Ultimately, this work contributes to the advancement of fundamental knowledge and practical applications of accurate preclinical M. abscessus models, thereby facilitating progress towards improved therapies for M. abscessus infections.},
}

@article {pmid38688866,
year = {2024},
author = {Antoine, C and Laforêt, F and Fall, A and Blasdel, B and Delcenserie, V and Thiry, D},
title = {K1 Capsule-dependent phage-driven evolution in Escherichia coli leading to phage resistance and biofilm production.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jambio/lxae109},
pmid = {38688866},
issn = {1365-2672},
abstract = {AIMS: Understanding bacterial phage resistance mechanisms has implications for developing phage-based therapies. This study aimed to explore the development of phage resistance in Escherichia coli K1 isolates' to K1-ULINTec4, a K1-dependent bacteriophage.

METHODS AND RESULTS: Resistant colonies were isolated from two different strains (APEC 45 and C5), both previously exposed to K1-ULINTec4. Genome analysis and several parameters were assessed, including growth capacity, phage adsorption, phenotypic impact at capsular level, biofilm production and virulence in the in-vivo Galleria mellonella larvae model. One out of the 6 resistant isolates exhibited a significantly slower growth rate suggesting the presence of a resistance mechanism altering its fitness. Comparative genomic analysis revealed insertion sequences in the region 2 of the kps gene cluster involved in the capsule biosynthesis. In addition, an immunoassay targeting the K1 capsule showed a very low positive reaction compared to the control. Nevertheless, microscopic images of resistant strains revealed the presence of capsules with a clustered organization of bacterial cells and biofilm assessment showed an increased biofilm production compared to the sensitive strains. In the G. mellonella model, larvae infected with phage-resistant isolates showed better survival rates than larvae infected with phage-sensitive strains.

CONCLUSIONS: A phage resistance mechanism was identified at the genomic level and had a negative impact on the K1 capsule production. The resistant isolates showed an increased biofilm production, and a decreased virulence in vivo.},
}