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RJR: Recommended Bibliography 24 Apr 2025 at 01:39 Created:
Biofilm
Wikipedia: Biofilm A biofilm is any group of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPS). The EPS components are produced by the cells within the biofilm and are typically a polymeric conglomeration of extracellular DNA, proteins, and polysaccharides. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, biofilms are frequently described metaphorically as cities for microbes. Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single-cells that may float or swim in a liquid medium. Biofilms can be present on the teeth of most animals as dental plaque, where they may cause tooth decay and gum disease. Microbes form a biofilm in response to many factors, which may include cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics. When a cell switches to the biofilm mode of growth, it undergoes a phenotypic shift in behavior in which large suites of genes are differentially regulated.
Created with PubMed® Query: ( biofilm[title] NOT 28392838[PMID] NOT 31293528[PMID] NOT 29372251[PMID] ) NOT pmcbook NOT ispreviousversion
Citations The Papers (from PubMed®)
RevDate: 2025-04-22
Comparative analysis of antimicrobial activity and oxidative damage induced by laser ablation with indocyanine green versus aPDT with methylene blue and curcumin on E. coli biofilm in root canals.
Odontology [Epub ahead of print].
Laser ablation and Antimicrobial Photodynamic Therapy (aPDT) serve as adjunctive treatments to enhance microbial reduction in endodontic root canals. This in vitro study assessed laser ablation with Indocyanine Green (ICG) compared to aPDT using Methylene Blue (MB) and Curcumin (CUR) photosensitizers for reducing E. coli biofilms and inducing oxidative damage in root canals. Methods Standardized bovine upper incisor roots (n = 100) were contaminated with E. coli for 10 days to form biofilms. Groups included ICG 0.05% activated by infrared diode laser, CUR 0.05% activated by blue LED, MB 0.01% activated by red laser, sterile saline (NC), and 2.5% sodium hypochlorite (PC). Root canal samples were collected pre- and post-treatment, plated on BHI agar for CFU/mL counting. Oxidative damage was assessed using TBARS and carbonylated protein methods. Percentage reduction data underwent two-way ANOVA and Student-Newman-Keuls test, Kruskal-Wallis, and Dunn's tests for CFU reduction, and one-way ANOVA (p < 0.05) for oxidative damage. Results No statistical differences were found among groups for E. coli reduction. All groups had higher reduction than NC and lower reduction than PC (p < 0.05). ICG and CUR showed higher oxidative damage than MB and controls in protein carbonyl analyses. In TBARS analysis, ICG exhibited the greatest oxidative damage, statistically higher than other photosensitizers, negative, and positive controls. Conclusion There was no difference between laser ablation with ICG and aPDT with CUR and MB, which were less effective in bacterial reduction than NaOCl. However, ICG-induced higher oxidative damage in Gram-negative bacteria, suggesting its potential as an adjunctive therapy in root canal procedures.
Additional Links: PMID-40261531
PubMed:
Citation:
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@article {pmid40261531,
year = {2025},
author = {Rodrigues, GWL and Del Bianco Vargas Gouveia, S and Oliveira, LC and de Freitas, RN and Dourado, NG and Sacoman, CA and Ribeiro, APF and Chaves-Neto, AH and Sivieri-Araújo, G and de Toledo Leonardo, R and Cintra, LTA and Jacinto, RC},
title = {Comparative analysis of antimicrobial activity and oxidative damage induced by laser ablation with indocyanine green versus aPDT with methylene blue and curcumin on E. coli biofilm in root canals.},
journal = {Odontology},
volume = {},
number = {},
pages = {},
pmid = {40261531},
issn = {1618-1255},
support = {001//Specialized Research Fund for the Doctoral Program of Higher Education of China/ ; 2023/02279-4//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; },
abstract = {Laser ablation and Antimicrobial Photodynamic Therapy (aPDT) serve as adjunctive treatments to enhance microbial reduction in endodontic root canals. This in vitro study assessed laser ablation with Indocyanine Green (ICG) compared to aPDT using Methylene Blue (MB) and Curcumin (CUR) photosensitizers for reducing E. coli biofilms and inducing oxidative damage in root canals. Methods Standardized bovine upper incisor roots (n = 100) were contaminated with E. coli for 10 days to form biofilms. Groups included ICG 0.05% activated by infrared diode laser, CUR 0.05% activated by blue LED, MB 0.01% activated by red laser, sterile saline (NC), and 2.5% sodium hypochlorite (PC). Root canal samples were collected pre- and post-treatment, plated on BHI agar for CFU/mL counting. Oxidative damage was assessed using TBARS and carbonylated protein methods. Percentage reduction data underwent two-way ANOVA and Student-Newman-Keuls test, Kruskal-Wallis, and Dunn's tests for CFU reduction, and one-way ANOVA (p < 0.05) for oxidative damage. Results No statistical differences were found among groups for E. coli reduction. All groups had higher reduction than NC and lower reduction than PC (p < 0.05). ICG and CUR showed higher oxidative damage than MB and controls in protein carbonyl analyses. In TBARS analysis, ICG exhibited the greatest oxidative damage, statistically higher than other photosensitizers, negative, and positive controls. Conclusion There was no difference between laser ablation with ICG and aPDT with CUR and MB, which were less effective in bacterial reduction than NaOCl. However, ICG-induced higher oxidative damage in Gram-negative bacteria, suggesting its potential as an adjunctive therapy in root canal procedures.},
}
RevDate: 2025-04-22
CmpDate: 2025-04-22
Role of advanced cleaning and sanitation techniques in biofilm prevention on dairy equipment.
Comprehensive reviews in food science and food safety, 24(3):e70176.
Biofilm formation on dairy equipment is a persistent challenge in the dairy industry, contributing to product contamination, equipment inefficiency, and economic losses. Traditional methods such as manual cleaning and basic chemical sanitation are discussed as foundational approaches, followed by an in-depth investigation of cutting-edge technologies, including clean-in-place systems, high-pressure cleaning, foam cleaning, ultrasonic and electrochemical cleaning, dry ice blasting, robotics, nanotechnology-based agents, enzymatic cleaners, and oxidizing agents. Enhanced sanitation techniques, such as dry steam, pulsed light, acidic and alkaline electrolyzed water, hydrogen peroxide vapor, microbubble technology, and biodegradable biocides, are highlighted for their potential to achieve superior sanitation while promoting sustainability. The effectiveness, feasibility, and limitations of these methods are evaluated, emphasizing their role in maintaining dairy equipment hygiene and reducing biofilm-associated risks. Additionally, challenges, such as equipment compatibility, cost, and regulatory compliance, are addressed, along with insights into future directions and innovations, including automation, smart cleaning systems, and green cleaning solutions. This review provides a comprehensive resource for researchers, industry professionals, and policymakers aiming to tackle biofilm formation in dairy production systems and enhance food safety, operational efficiency, and sustainability.
Additional Links: PMID-40260792
Publisher:
PubMed:
Citation:
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@article {pmid40260792,
year = {2025},
author = {Chowdhury, MAH and Reem, CSA and Ashrafudoulla, M and Rahman, MA and Shaila, S and Jie-Won Ha, A and Ha, SD},
title = {Role of advanced cleaning and sanitation techniques in biofilm prevention on dairy equipment.},
journal = {Comprehensive reviews in food science and food safety},
volume = {24},
number = {3},
pages = {e70176},
doi = {10.1111/1541-4337.70176},
pmid = {40260792},
issn = {1541-4337},
support = {//National Research Foundation of Korea (NRF)/ ; 21153MFDS605//Ministry of food and drug safety 2025/ ; RS202400339436//Korea government (MSIT)/ ; },
mesh = {*Biofilms/growth & development ; *Dairying/instrumentation/methods ; *Sanitation/methods ; *Equipment Contamination/prevention & control ; },
abstract = {Biofilm formation on dairy equipment is a persistent challenge in the dairy industry, contributing to product contamination, equipment inefficiency, and economic losses. Traditional methods such as manual cleaning and basic chemical sanitation are discussed as foundational approaches, followed by an in-depth investigation of cutting-edge technologies, including clean-in-place systems, high-pressure cleaning, foam cleaning, ultrasonic and electrochemical cleaning, dry ice blasting, robotics, nanotechnology-based agents, enzymatic cleaners, and oxidizing agents. Enhanced sanitation techniques, such as dry steam, pulsed light, acidic and alkaline electrolyzed water, hydrogen peroxide vapor, microbubble technology, and biodegradable biocides, are highlighted for their potential to achieve superior sanitation while promoting sustainability. The effectiveness, feasibility, and limitations of these methods are evaluated, emphasizing their role in maintaining dairy equipment hygiene and reducing biofilm-associated risks. Additionally, challenges, such as equipment compatibility, cost, and regulatory compliance, are addressed, along with insights into future directions and innovations, including automation, smart cleaning systems, and green cleaning solutions. This review provides a comprehensive resource for researchers, industry professionals, and policymakers aiming to tackle biofilm formation in dairy production systems and enhance food safety, operational efficiency, and sustainability.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Dairying/instrumentation/methods
*Sanitation/methods
*Equipment Contamination/prevention & control
RevDate: 2025-04-23
Bacteriological Profile of Diabetic Foot Ulcer With Special Reference to Biofilm Formation.
Cureus, 17(3):e80974.
Introduction Diabetes mellitus is a metabolic disorder characterized by abnormally high sugar levels in the blood for prolonged periods of time. The world's largest number of diabetics resides in India, making it the world's diabetic capital, with a diabetic foot ulcer (DFU) incidence of around 8-17%. Due to the polymicrobial and multidrug resistant (MDR) nature of DFUs, antimicrobial susceptibility testing is of high importance to help treat patients effectively and prevent the development of MDR bacteria. The ability to form biofilms is a significant additive to virulence of an organism that causes an able strain to be resistant to more antibiotics as compared to a free-living strain, thereby further delaying the healing of DFUs. Materials and methods This study included 74 samples collected from patients with DFUs, out of which 69 (93.24%) yielded growth on culture. Gram staining was done for the direct microscopy, isolation, and determination of organism, and the detection of biofilm formers using Congo Red Agar plates. Data were tabulated and statistically analyzed. Results Out of 74 samples collected, 69 (93.24%) yielded growth on culturing, with 5 (6.76%) cultures coming back negative. On Gram staining, 42 (56.8%) samples showed Gram-positive cocci and 53 (71.6%) showed Gram-negative bacilli. On isolating organisms from the samples, 16 (21.7%) samples had Pseudomonas aeruginosa, followed by Klebsiella pneumoniae at 13 (17.6%) and Proteus mirabilis and Escherichia coli at 11 each (14.9%), indicating a Gram-negative bacteria predominance. Of the Gram-positive bacteria isolated, Staphylococcus aureus stands at two (2.7%) and Streptococcus pyogenes at one (1.4%). The prevailing monomicrobiality could be attributed to antibiotic administration prior to sample collection. On antibiotic sensitivity of organisms tested against each antibiotic, more than 75% of tested samples were resistant to ampicillin, cefuroxime, and erythromycin, and around 70% and more of tested samples were sensitive to ertapenem, meropenem, amikacin, gentamicin, benzylpenicillin, vancomycin, and clindamycin. Out of the 69 positive cultures, 29 (42.03%) yielded biofilm formers. Pseudomonas aeruginosa was the predominant biofilm former with 10 (34.48%) of 29 of total biofilm-forming isolates, followed by E. coli and K. pneumoniae with five each (17.24%) and Proteus mirabilis with three samples (10.34%). Regarding strains forming biofilms according to bacterium species, S. aureus was predominant, with 100% (two out of two samples) of isolates forming biofilms. Staphylococcus aureus was followed by Pseudomonas aeruginosa with 62.5% (10 out of 16 samples), Acinetobacter baumannii (two out of four samples) and Enterobacter cloacae (one out of two samples) with 50% each, E. coli with 45.45% (5 out of 11 samples), and K. pneumoniae with 38.46% (5 out of 13 samples) of isolates forming biofilms. It should be noted that only two S. aureus, four A. baumannii, and two Enterobacter cloacae samples were isolated in comparison to a larger number of Gram-negative bacteria. This study has found that 100% of multidrug-resistant organisms (MDROs) are biofilm formers. Conclusion The ability to form biofilms adds immensely to the virulence and antibiotic resistance. Detection of biofilm formers is non-invasive and convenient to measure and would help provide insight into antibiotics to be administered to the patient, thereby reducing development of MDROs and reducing healing time.
Additional Links: PMID-40260359
PubMed:
Citation:
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@article {pmid40260359,
year = {2025},
author = {Tirumala, N and K, LR},
title = {Bacteriological Profile of Diabetic Foot Ulcer With Special Reference to Biofilm Formation.},
journal = {Cureus},
volume = {17},
number = {3},
pages = {e80974},
pmid = {40260359},
issn = {2168-8184},
abstract = {Introduction Diabetes mellitus is a metabolic disorder characterized by abnormally high sugar levels in the blood for prolonged periods of time. The world's largest number of diabetics resides in India, making it the world's diabetic capital, with a diabetic foot ulcer (DFU) incidence of around 8-17%. Due to the polymicrobial and multidrug resistant (MDR) nature of DFUs, antimicrobial susceptibility testing is of high importance to help treat patients effectively and prevent the development of MDR bacteria. The ability to form biofilms is a significant additive to virulence of an organism that causes an able strain to be resistant to more antibiotics as compared to a free-living strain, thereby further delaying the healing of DFUs. Materials and methods This study included 74 samples collected from patients with DFUs, out of which 69 (93.24%) yielded growth on culture. Gram staining was done for the direct microscopy, isolation, and determination of organism, and the detection of biofilm formers using Congo Red Agar plates. Data were tabulated and statistically analyzed. Results Out of 74 samples collected, 69 (93.24%) yielded growth on culturing, with 5 (6.76%) cultures coming back negative. On Gram staining, 42 (56.8%) samples showed Gram-positive cocci and 53 (71.6%) showed Gram-negative bacilli. On isolating organisms from the samples, 16 (21.7%) samples had Pseudomonas aeruginosa, followed by Klebsiella pneumoniae at 13 (17.6%) and Proteus mirabilis and Escherichia coli at 11 each (14.9%), indicating a Gram-negative bacteria predominance. Of the Gram-positive bacteria isolated, Staphylococcus aureus stands at two (2.7%) and Streptococcus pyogenes at one (1.4%). The prevailing monomicrobiality could be attributed to antibiotic administration prior to sample collection. On antibiotic sensitivity of organisms tested against each antibiotic, more than 75% of tested samples were resistant to ampicillin, cefuroxime, and erythromycin, and around 70% and more of tested samples were sensitive to ertapenem, meropenem, amikacin, gentamicin, benzylpenicillin, vancomycin, and clindamycin. Out of the 69 positive cultures, 29 (42.03%) yielded biofilm formers. Pseudomonas aeruginosa was the predominant biofilm former with 10 (34.48%) of 29 of total biofilm-forming isolates, followed by E. coli and K. pneumoniae with five each (17.24%) and Proteus mirabilis with three samples (10.34%). Regarding strains forming biofilms according to bacterium species, S. aureus was predominant, with 100% (two out of two samples) of isolates forming biofilms. Staphylococcus aureus was followed by Pseudomonas aeruginosa with 62.5% (10 out of 16 samples), Acinetobacter baumannii (two out of four samples) and Enterobacter cloacae (one out of two samples) with 50% each, E. coli with 45.45% (5 out of 11 samples), and K. pneumoniae with 38.46% (5 out of 13 samples) of isolates forming biofilms. It should be noted that only two S. aureus, four A. baumannii, and two Enterobacter cloacae samples were isolated in comparison to a larger number of Gram-negative bacteria. This study has found that 100% of multidrug-resistant organisms (MDROs) are biofilm formers. Conclusion The ability to form biofilms adds immensely to the virulence and antibiotic resistance. Detection of biofilm formers is non-invasive and convenient to measure and would help provide insight into antibiotics to be administered to the patient, thereby reducing development of MDROs and reducing healing time.},
}
RevDate: 2025-04-21
Self-Powered Oxygen Microbubble Generator for Decontamination of Anaerobic Biofilm-Fouled Bioimplants.
ACS biomaterials science & engineering [Epub ahead of print].
Biomedical devices often feature a microgap: confined, minuscule spaces that foster bacterial infiltration and biofilm formation. For instance, peri-implantitis with prevalence rates of 4.7-45% at the patient level is a major complication driven by biofilm infections, characterized by chronic inflammation and implant failure. Anaerobic biofilm residing within the microgap serves as a major source of the peri-implantitis, but tools that remove the biofilm are lacking. Therefore, this study presents a novel preventive strategy employing self-powered microbubbler (SM) for targeted decontamination of micrographs in dental implants. SMs are assembled by doping diatoms with MnO2 nanosheets. These particles are activated to generate O2 microbubbles in H2O2 solution via catalase-mimetic activity and can penetrate the biofilm structures. The resulting oxygen bubbles induce effective mechanical disruption and oxygenation within biofilm-mimicking gelatin hydrogels and Porphyromonas gingivalis biofilms found in the peri-implantitis-affected implants. Such biofilm removal from the microgap restored mechanical stability at implant abutment-fixture connections and reduced bacterial leakage. Multispecies biofilms from patient-derived implants were similarly decontaminated with the mixture of SM-H2O2 outperforming conventional antiseptics like 0.2% chlorhexidine and 3% H2O2 alone. This innovative approach extends beyond dental implants to address biofilm-associated challenges in various biomedical devices with microgap vulnerabilities. Overall, SM-based treatments will offer an efficient and nondamaging solution to enhance the sterility and longevity of various bioimplants with intricated and confined structure.
Additional Links: PMID-40257245
Publisher:
PubMed:
Citation:
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@article {pmid40257245,
year = {2025},
author = {Lee, EH and Kim, H and Lee, JH and Kim, Y and Kwon, HB and Lim, YJ and Kong, H and Lee, SW and Kim, MJ},
title = {Self-Powered Oxygen Microbubble Generator for Decontamination of Anaerobic Biofilm-Fouled Bioimplants.},
journal = {ACS biomaterials science & engineering},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsbiomaterials.5c00303},
pmid = {40257245},
issn = {2373-9878},
abstract = {Biomedical devices often feature a microgap: confined, minuscule spaces that foster bacterial infiltration and biofilm formation. For instance, peri-implantitis with prevalence rates of 4.7-45% at the patient level is a major complication driven by biofilm infections, characterized by chronic inflammation and implant failure. Anaerobic biofilm residing within the microgap serves as a major source of the peri-implantitis, but tools that remove the biofilm are lacking. Therefore, this study presents a novel preventive strategy employing self-powered microbubbler (SM) for targeted decontamination of micrographs in dental implants. SMs are assembled by doping diatoms with MnO2 nanosheets. These particles are activated to generate O2 microbubbles in H2O2 solution via catalase-mimetic activity and can penetrate the biofilm structures. The resulting oxygen bubbles induce effective mechanical disruption and oxygenation within biofilm-mimicking gelatin hydrogels and Porphyromonas gingivalis biofilms found in the peri-implantitis-affected implants. Such biofilm removal from the microgap restored mechanical stability at implant abutment-fixture connections and reduced bacterial leakage. Multispecies biofilms from patient-derived implants were similarly decontaminated with the mixture of SM-H2O2 outperforming conventional antiseptics like 0.2% chlorhexidine and 3% H2O2 alone. This innovative approach extends beyond dental implants to address biofilm-associated challenges in various biomedical devices with microgap vulnerabilities. Overall, SM-based treatments will offer an efficient and nondamaging solution to enhance the sterility and longevity of various bioimplants with intricated and confined structure.},
}
RevDate: 2025-04-22
A Comparison Between Multisonic and Ultrasonic Irrigant Activation Techniques for Multispecies Biofilm Removal During Root Canal Disinfection: A Systematic Review.
Cureus, 17(3):e80938.
This systematic review aims to compare multisonic and ultrasonic irrigant activation techniques in polymicrobial biofilm removal. We conducted a literature search involving SCOPUS, PubMed, Cochrane, EBSCO host, and LILACS databases from inception to December 2024, in addition to a manual search using Google Scholar. The risk of bias assessment was done using the guidelines described for in vitro studies and the criteria for evaluation was based on JBI criteria and CRIS guidelines for quality assessment of in vitro studies. Three articles were included in the final analysis. The included studies evaluated biofilm removal in extracted teeth models incubated with biofilm; while two studies used quantitative polymerase chain reaction (qPCR) methodology, one used colony forming unit (CFU). Except in the study by Llerena et al., the GentleWave® multisonic System (GWS) outperformed ultrasonic irrigant activation (UI) in terms of biofilm removal. Despite the limitations of this systematic review, multisonic irrigant activation demonstrated similar efficacy in reducing intraradicular biofilm when compared to ultrasonic irrigant activation.
Additional Links: PMID-40255811
PubMed:
Citation:
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@article {pmid40255811,
year = {2025},
author = {Varadan, P and Ra, S and Rajendran, MR},
title = {A Comparison Between Multisonic and Ultrasonic Irrigant Activation Techniques for Multispecies Biofilm Removal During Root Canal Disinfection: A Systematic Review.},
journal = {Cureus},
volume = {17},
number = {3},
pages = {e80938},
pmid = {40255811},
issn = {2168-8184},
abstract = {This systematic review aims to compare multisonic and ultrasonic irrigant activation techniques in polymicrobial biofilm removal. We conducted a literature search involving SCOPUS, PubMed, Cochrane, EBSCO host, and LILACS databases from inception to December 2024, in addition to a manual search using Google Scholar. The risk of bias assessment was done using the guidelines described for in vitro studies and the criteria for evaluation was based on JBI criteria and CRIS guidelines for quality assessment of in vitro studies. Three articles were included in the final analysis. The included studies evaluated biofilm removal in extracted teeth models incubated with biofilm; while two studies used quantitative polymerase chain reaction (qPCR) methodology, one used colony forming unit (CFU). Except in the study by Llerena et al., the GentleWave® multisonic System (GWS) outperformed ultrasonic irrigant activation (UI) in terms of biofilm removal. Despite the limitations of this systematic review, multisonic irrigant activation demonstrated similar efficacy in reducing intraradicular biofilm when compared to ultrasonic irrigant activation.},
}
RevDate: 2025-04-22
Developing a Urinary Catheter with Anti-Biofilm Coated Surface Using Phyto-Assisted Synthesis of Zinc Oxide Nanoparticles.
Infection and drug resistance, 18:1881-1893.
BACKGROUND: Biofilm-related infections represent one of the major challenging health problems that enhances antimicrobial resistance with subsequent treatment failure of catheter-associated urinary tract infections (CAUTIs).
AIM: This study aimed to employ and comprehensively characterize the use of nanoparticles to inhibit bacterial biofilm formation. Zinc oxide nanoparticles (ZnO-NPs) are considered one of the most important biofilm inhibitors.
METHODS: The current study aimed to characterize the influence of the bioreductive green synthesis of ZnO-NPs using pomegranate peel extract on bacterial colonization to protect against urinary catheter infections. ZnO-NPs were investigated for their physicochemical properties using UV, FTIR, Dynamic light scattering, and TEM. Catheters were coated with ZnO-NPs using Pistacia lentiscus (mastic), and the slow release of free zinc ions (Zn[+2]) from, the ZnO-NPs-coated catheters, was evaluated using the ICP-AES technique.
RESULTS: The current study revealed that catheter coated by ZnO-NPs exhibited a sustained antibiofilm activity against biofilm-forming and antibiotic-resistant clinical isolates of Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa strains.
CONCLUSION: The present study supports the efficiency of ZnO-NPs as a good candidate for prevention of biofilm formation.
Additional Links: PMID-40255461
PubMed:
Citation:
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@article {pmid40255461,
year = {2025},
author = {Goda, RM and Maghrabi, IA and El-Badawy, MF and Kabel, AM and Omar, AA and El-Morsi, RM and Ramadan, HA and Shohayeb, MM},
title = {Developing a Urinary Catheter with Anti-Biofilm Coated Surface Using Phyto-Assisted Synthesis of Zinc Oxide Nanoparticles.},
journal = {Infection and drug resistance},
volume = {18},
number = {},
pages = {1881-1893},
pmid = {40255461},
issn = {1178-6973},
abstract = {BACKGROUND: Biofilm-related infections represent one of the major challenging health problems that enhances antimicrobial resistance with subsequent treatment failure of catheter-associated urinary tract infections (CAUTIs).
AIM: This study aimed to employ and comprehensively characterize the use of nanoparticles to inhibit bacterial biofilm formation. Zinc oxide nanoparticles (ZnO-NPs) are considered one of the most important biofilm inhibitors.
METHODS: The current study aimed to characterize the influence of the bioreductive green synthesis of ZnO-NPs using pomegranate peel extract on bacterial colonization to protect against urinary catheter infections. ZnO-NPs were investigated for their physicochemical properties using UV, FTIR, Dynamic light scattering, and TEM. Catheters were coated with ZnO-NPs using Pistacia lentiscus (mastic), and the slow release of free zinc ions (Zn[+2]) from, the ZnO-NPs-coated catheters, was evaluated using the ICP-AES technique.
RESULTS: The current study revealed that catheter coated by ZnO-NPs exhibited a sustained antibiofilm activity against biofilm-forming and antibiotic-resistant clinical isolates of Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa strains.
CONCLUSION: The present study supports the efficiency of ZnO-NPs as a good candidate for prevention of biofilm formation.},
}
RevDate: 2025-04-19
CmpDate: 2025-04-19
Biofilm formation and analysis of EPS architecture comprising polysaccharides and lipids by Pseudomonas aeruginosa and Escherichia coli on food processing surfaces.
Food research international (Ottawa, Ont.), 209:116274.
Biofilms are silent but formidable threats in seafood processing, where Pseudomonas aeruginosa and Escherichia coli can quickly transform contact surfaces into reservoirs of contamination. This study explores the dynamic biofilm formation on aluminum, silicone rubber, stainless steel, and polyethylene terephthalate over 24 and 72 h. Quantitative assays including Colony Forming Unit (CFU), Crystal Violet (CV), 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) revealed a significant increase in biofilm density, particularly on aluminum and silicone rubber. Fourier-Transform Infrared Spectroscopy (FTIR) and [1]H Nuclear Magnetic Resonance (NMR) analyses showed that biofilm EPS exhibits an evolving amphiphilic nature, with stable polysaccharides and increasing lipid content enhancing resilience. Confocal Laser Scanning Microscopy (CLSM), and Field Emission Scanning Electron Microscopy (FE-SEM) captured the shift from early attachment to mature, dense biofilms. These findings underscore the crucial impact of surface material on biofilm growth and the pressing need for tailored cleaning protocols to curb contamination risks in food processing environments.
Additional Links: PMID-40253144
Publisher:
PubMed:
Citation:
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@article {pmid40253144,
year = {2025},
author = {Akter, S and Rahman, MA and Ashrafudoulla, M and Ha, SD},
title = {Biofilm formation and analysis of EPS architecture comprising polysaccharides and lipids by Pseudomonas aeruginosa and Escherichia coli on food processing surfaces.},
journal = {Food research international (Ottawa, Ont.)},
volume = {209},
number = {},
pages = {116274},
doi = {10.1016/j.foodres.2025.116274},
pmid = {40253144},
issn = {1873-7145},
mesh = {*Biofilms/growth & development ; *Pseudomonas aeruginosa/physiology/growth & development ; *Escherichia coli/physiology/growth & development ; *Food Handling ; *Food Microbiology ; *Extracellular Polymeric Substance Matrix/chemistry/metabolism ; *Polysaccharides, Bacterial ; Spectroscopy, Fourier Transform Infrared ; Microscopy, Electron, Scanning ; Bacterial Adhesion ; *Lipids/analysis ; Surface Properties ; Stainless Steel ; },
abstract = {Biofilms are silent but formidable threats in seafood processing, where Pseudomonas aeruginosa and Escherichia coli can quickly transform contact surfaces into reservoirs of contamination. This study explores the dynamic biofilm formation on aluminum, silicone rubber, stainless steel, and polyethylene terephthalate over 24 and 72 h. Quantitative assays including Colony Forming Unit (CFU), Crystal Violet (CV), 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) revealed a significant increase in biofilm density, particularly on aluminum and silicone rubber. Fourier-Transform Infrared Spectroscopy (FTIR) and [1]H Nuclear Magnetic Resonance (NMR) analyses showed that biofilm EPS exhibits an evolving amphiphilic nature, with stable polysaccharides and increasing lipid content enhancing resilience. Confocal Laser Scanning Microscopy (CLSM), and Field Emission Scanning Electron Microscopy (FE-SEM) captured the shift from early attachment to mature, dense biofilms. These findings underscore the crucial impact of surface material on biofilm growth and the pressing need for tailored cleaning protocols to curb contamination risks in food processing environments.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Pseudomonas aeruginosa/physiology/growth & development
*Escherichia coli/physiology/growth & development
*Food Handling
*Food Microbiology
*Extracellular Polymeric Substance Matrix/chemistry/metabolism
*Polysaccharides, Bacterial
Spectroscopy, Fourier Transform Infrared
Microscopy, Electron, Scanning
Bacterial Adhesion
*Lipids/analysis
Surface Properties
Stainless Steel
RevDate: 2025-04-21
CmpDate: 2025-04-19
Protection with a collagen wound matrix containing polyhexamethylene biguanide supports innate wound healing in biofilm-infected porcine wounds.
Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society, 33(2):e70025.
Over 90% of chronic wounds have biofilm infections, making the need for inhibiting reformation of biofilm post-debridement paramount to support progression through the normal phases of wound healing. Herein, we describe a porcine wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) and examine the ability of an antimicrobial barrier composed of native type I collagen and polyhexamethylene biguanide (PCMP) to serve as a barrier to protect wounds and support progression through the innate wound healing cascade. Wounds were inoculated with MRSA and allowed to form a biofilm for 72 h, subjected to standard of care sharp debridement, then either left untreated or received PCMP for 5, 10, 15 or 20 days. Wounds were assessed for bioburden, wound closure and expression of genes related to wound healing. Wounds treated with PCMP exhibited statistically lower MRSA levels compared to untreated controls and achieved 90% closure by 2 weeks of treatment. Gene expression analysis demonstrated that by reducing bacterial load, wounds progressed through the innate wound healing cascade, while untreated wounds exhibited a dampening of the immune response. Additionally, for randomly assigned wounds, PCMP was not reapplied at dressing changes to assess the impact of inconsistent wound protection. At all timepoints, a resurgence in bioburden was observed following removal of PCMP if the wounds had not fully closed. This study highlights the value of PCMP as an antimicrobial barrier and the importance of protecting wounds through closure and resolution.
Additional Links: PMID-40251887
PubMed:
Citation:
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@article {pmid40251887,
year = {2025},
author = {Davis, SC and Avery, JT and Gil, J and Solis, MR and Jozic, I and Kimmerling, KA and Mowry, KC},
title = {Protection with a collagen wound matrix containing polyhexamethylene biguanide supports innate wound healing in biofilm-infected porcine wounds.},
journal = {Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society},
volume = {33},
number = {2},
pages = {e70025},
pmid = {40251887},
issn = {1524-475X},
support = {//Organogenesis/ ; },
mesh = {Animals ; *Wound Healing/drug effects ; *Biguanides/pharmacology ; *Biofilms/drug effects ; Swine ; *Methicillin-Resistant Staphylococcus aureus/drug effects ; *Wound Infection/microbiology/pathology/drug therapy ; Disease Models, Animal ; *Staphylococcal Infections/microbiology/pathology/drug therapy ; *Collagen/pharmacology ; Debridement ; Immunity, Innate ; },
abstract = {Over 90% of chronic wounds have biofilm infections, making the need for inhibiting reformation of biofilm post-debridement paramount to support progression through the normal phases of wound healing. Herein, we describe a porcine wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) and examine the ability of an antimicrobial barrier composed of native type I collagen and polyhexamethylene biguanide (PCMP) to serve as a barrier to protect wounds and support progression through the innate wound healing cascade. Wounds were inoculated with MRSA and allowed to form a biofilm for 72 h, subjected to standard of care sharp debridement, then either left untreated or received PCMP for 5, 10, 15 or 20 days. Wounds were assessed for bioburden, wound closure and expression of genes related to wound healing. Wounds treated with PCMP exhibited statistically lower MRSA levels compared to untreated controls and achieved 90% closure by 2 weeks of treatment. Gene expression analysis demonstrated that by reducing bacterial load, wounds progressed through the innate wound healing cascade, while untreated wounds exhibited a dampening of the immune response. Additionally, for randomly assigned wounds, PCMP was not reapplied at dressing changes to assess the impact of inconsistent wound protection. At all timepoints, a resurgence in bioburden was observed following removal of PCMP if the wounds had not fully closed. This study highlights the value of PCMP as an antimicrobial barrier and the importance of protecting wounds through closure and resolution.},
}
MeSH Terms:
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hide MeSH Terms
Animals
*Wound Healing/drug effects
*Biguanides/pharmacology
*Biofilms/drug effects
Swine
*Methicillin-Resistant Staphylococcus aureus/drug effects
*Wound Infection/microbiology/pathology/drug therapy
Disease Models, Animal
*Staphylococcal Infections/microbiology/pathology/drug therapy
*Collagen/pharmacology
Debridement
Immunity, Innate
RevDate: 2025-04-20
Biofilm inhibition and antagonism of Klebsiella pneumoniae by probiotic lactic acid bacteria (LAB) isolated from raw cow milk.
Microbial pathogenesis, 204:107603 pii:S0882-4010(25)00328-6 [Epub ahead of print].
Lactic acid bacteria (LAB) with their potential health benefits are naturally prevalent in dairy and fermented food products. This probiotic microbiota can be an alternative biological tool for controlling other pathogenic bacteria. The study aimed to isolate lactic acid bacteria (LAB) from raw cow milk and evaluate their probiotic potential. Twelve gram-positive isolates showing tolerance to bile salt, acid, and low pH were identified by 16S rRNA sequencing, which revealed the isolates belong to the genera including Lactococcus, Enterococcus, Streptococcus, Bacillus, and Weissella. In case of probiotic potential, the isolates exhibited arrays of probiotic properties: autoaggregation (33.65-84.63 %), co-aggregation (8.17-83.22 %), cell surface hydrophobicity for both polar (13.37-90.24 %) and non-polar solvents (5.52-53.58 %) and able to form biofilm (75 % weak, 16.67 % moderate and 8.33 % strong). Statistical analysis revealed the correlation pattern between the probiotic properties and showed a significant strong positive correlation between cell surface hydrophobicity and aggregation. Additionally, three isolates L. lactis, W. confusa, and E. gallinarum that were sensitive to antibiotics, able to produce biofilm, and did not contain virulence genes were able to reduce the biofilm formation of pathogen K. pneumoniae (1.3-4 log) in the co-culture assay. These Findings suggest that LAB from the raw cow milk could serve as a natural biocontrol agent for preventing and controlling K. pneumoniae biofilm formation and pave the way for innovative intervention of LAB in food safety and clinical settings.
Additional Links: PMID-40250494
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PubMed:
Citation:
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@article {pmid40250494,
year = {2025},
author = {Jhuma, TA and Dey, SS and Sarkar, R and Siddique, S and Moniruzzaman, M and Chowdhury, A},
title = {Biofilm inhibition and antagonism of Klebsiella pneumoniae by probiotic lactic acid bacteria (LAB) isolated from raw cow milk.},
journal = {Microbial pathogenesis},
volume = {204},
number = {},
pages = {107603},
doi = {10.1016/j.micpath.2025.107603},
pmid = {40250494},
issn = {1096-1208},
abstract = {Lactic acid bacteria (LAB) with their potential health benefits are naturally prevalent in dairy and fermented food products. This probiotic microbiota can be an alternative biological tool for controlling other pathogenic bacteria. The study aimed to isolate lactic acid bacteria (LAB) from raw cow milk and evaluate their probiotic potential. Twelve gram-positive isolates showing tolerance to bile salt, acid, and low pH were identified by 16S rRNA sequencing, which revealed the isolates belong to the genera including Lactococcus, Enterococcus, Streptococcus, Bacillus, and Weissella. In case of probiotic potential, the isolates exhibited arrays of probiotic properties: autoaggregation (33.65-84.63 %), co-aggregation (8.17-83.22 %), cell surface hydrophobicity for both polar (13.37-90.24 %) and non-polar solvents (5.52-53.58 %) and able to form biofilm (75 % weak, 16.67 % moderate and 8.33 % strong). Statistical analysis revealed the correlation pattern between the probiotic properties and showed a significant strong positive correlation between cell surface hydrophobicity and aggregation. Additionally, three isolates L. lactis, W. confusa, and E. gallinarum that were sensitive to antibiotics, able to produce biofilm, and did not contain virulence genes were able to reduce the biofilm formation of pathogen K. pneumoniae (1.3-4 log) in the co-culture assay. These Findings suggest that LAB from the raw cow milk could serve as a natural biocontrol agent for preventing and controlling K. pneumoniae biofilm formation and pave the way for innovative intervention of LAB in food safety and clinical settings.},
}
RevDate: 2025-04-18
Molecular characterization, antibiotic resistance pattern, and biofilm formation of Vibrio parahaemolyticus isolated from tropical seafood.
Journal of AOAC International pii:8116182 [Epub ahead of print].
BACKGROUND: Vibrio parahaemolyticus in seafood poses a major public health concern, particularly in tropical regions.
OBJECTIVE: The present study aims to isolate, assess antibiotic susceptibility, and determine the biofilm-forming ability of V. parahaemolyticus strains isolated from seafood sold in Cochin, India.
METHODS: One hundred seafood samples were collected from retail markets in Cochin and analyzed for V. parahaemolyticus. Phenotypic identification was confirmed through biochemical assays and molecular characterization using polymerase chain reaction (PCR) targeting toxR, tdh, and trh genes. Biofilm formation was assessed using the microtiter plate-crystal violet assay, and antibiotic resistance was determined using the disc diffusion method.
RESULTS: V. parahaemolyticus was detected in 43.0% (43/100) of the total seafood analyzed. A total of 43 isolates were confirmed by the toxR gene, of which five carried the tdh gene, while none harbored the trh gene. Antimicrobial susceptibility testing revealed 100% resistance to ampicillin, whereas all isolates were fully susceptible to chloramphenicol. The multiple antibiotic resistance (MAR) index ranged from 0.13 to 0.50. Notably, some multidrug-resistant isolates exhibited strong biofilm formation at 37 °C.
CONCLUSION: The high prevalence of antibiotic-resistant V. parahaemolyticus in seafood sold in Cochin and their ability to form biofilms underscores the need for rigorous monitoring and effective control strategies to safeguard public health.
Additional Links: PMID-40249671
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PubMed:
Citation:
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@article {pmid40249671,
year = {2025},
author = {Nilavan, E and Kumar, A and Sivam, V and Vaiyapuri, M and Koombankallil, R and Joseph, TC and Swaminathan, TR},
title = {Molecular characterization, antibiotic resistance pattern, and biofilm formation of Vibrio parahaemolyticus isolated from tropical seafood.},
journal = {Journal of AOAC International},
volume = {},
number = {},
pages = {},
doi = {10.1093/jaoacint/qsaf037},
pmid = {40249671},
issn = {1944-7922},
abstract = {BACKGROUND: Vibrio parahaemolyticus in seafood poses a major public health concern, particularly in tropical regions.
OBJECTIVE: The present study aims to isolate, assess antibiotic susceptibility, and determine the biofilm-forming ability of V. parahaemolyticus strains isolated from seafood sold in Cochin, India.
METHODS: One hundred seafood samples were collected from retail markets in Cochin and analyzed for V. parahaemolyticus. Phenotypic identification was confirmed through biochemical assays and molecular characterization using polymerase chain reaction (PCR) targeting toxR, tdh, and trh genes. Biofilm formation was assessed using the microtiter plate-crystal violet assay, and antibiotic resistance was determined using the disc diffusion method.
RESULTS: V. parahaemolyticus was detected in 43.0% (43/100) of the total seafood analyzed. A total of 43 isolates were confirmed by the toxR gene, of which five carried the tdh gene, while none harbored the trh gene. Antimicrobial susceptibility testing revealed 100% resistance to ampicillin, whereas all isolates were fully susceptible to chloramphenicol. The multiple antibiotic resistance (MAR) index ranged from 0.13 to 0.50. Notably, some multidrug-resistant isolates exhibited strong biofilm formation at 37 °C.
CONCLUSION: The high prevalence of antibiotic-resistant V. parahaemolyticus in seafood sold in Cochin and their ability to form biofilms underscores the need for rigorous monitoring and effective control strategies to safeguard public health.},
}
RevDate: 2025-04-19
A biofilm-targeting lipo-peptoid to treat Pseudomonas aeruginosa and Staphylococcus aureus co-infections.
Biofilm, 9:100272.
Antibiotic-resistant bacterial infections are a significant clinical challenge, especially when involving multiple species. Antimicrobial peptides and their synthetic analogues, peptoids, which target bacterial cell membranes as well as intracellular components, offer potential solutions. We evaluated the biological activities of novel peptoids TM11-TM20, which include an additional charged NLys residue, against multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus, both in vitro and in vivo. Building on insights from previously reported compounds TM1-TM10, the lipo-peptoid TM18, which forms self-assembled ellipsoidal micelles, demonstrated potent antimicrobial, anti-biofilm, and anti-abscess activity. Transcriptome sequencing (RNA-seq) revealed that TM18 disrupted gene expression pathways linked to antibiotic resistance and tolerance, and biofilm formation in both pathogens. Under dual-species conditions, TM18 induced overlapping but attenuated transcriptional changes, suggesting a priming effect that enhances bacterial tolerance. In a murine skin infection model, TM18 significantly reduced dermonecrosis and bacterial burden in mono-species infections. When combined with the antibiotic meropenem, they synergistically nearly cleared co-infections. Our findings highlight that TM18 has potential as a novel therapeutic for combating antibiotic-resistant pathogens and associated biofilm-driven tolerance.
Additional Links: PMID-40248507
PubMed:
Citation:
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@article {pmid40248507,
year = {2025},
author = {Wardell, SJT and Yung, DBY and Nielsen, JE and Lamichhane, R and Sørensen, K and Molchanova, N and Herlan, C and Lin, JS and Bräse, S and Wise, LM and Barron, AE and Pletzer, D},
title = {A biofilm-targeting lipo-peptoid to treat Pseudomonas aeruginosa and Staphylococcus aureus co-infections.},
journal = {Biofilm},
volume = {9},
number = {},
pages = {100272},
pmid = {40248507},
issn = {2590-2075},
abstract = {Antibiotic-resistant bacterial infections are a significant clinical challenge, especially when involving multiple species. Antimicrobial peptides and their synthetic analogues, peptoids, which target bacterial cell membranes as well as intracellular components, offer potential solutions. We evaluated the biological activities of novel peptoids TM11-TM20, which include an additional charged NLys residue, against multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus, both in vitro and in vivo. Building on insights from previously reported compounds TM1-TM10, the lipo-peptoid TM18, which forms self-assembled ellipsoidal micelles, demonstrated potent antimicrobial, anti-biofilm, and anti-abscess activity. Transcriptome sequencing (RNA-seq) revealed that TM18 disrupted gene expression pathways linked to antibiotic resistance and tolerance, and biofilm formation in both pathogens. Under dual-species conditions, TM18 induced overlapping but attenuated transcriptional changes, suggesting a priming effect that enhances bacterial tolerance. In a murine skin infection model, TM18 significantly reduced dermonecrosis and bacterial burden in mono-species infections. When combined with the antibiotic meropenem, they synergistically nearly cleared co-infections. Our findings highlight that TM18 has potential as a novel therapeutic for combating antibiotic-resistant pathogens and associated biofilm-driven tolerance.},
}
RevDate: 2025-04-18
Biofilm Biology to Brain Health: Harnessing Microbial Wisdom to Uncover Amyloid Dissociating Bifunctional Nano Chaperones for Alzheimer's Therapeutics.
ACS chemical neuroscience [Epub ahead of print].
Microbial infections have long been implicated in the gut-brain link to Alzheimer's disease (AD). These infections may influence AD development either directly, through brain invasion, or indirectly via bacterial metabolites crossing the blood-brain-barrier (BBB) or interacting with the enteric nervous system (ENS). Such findings have inspired clinicians to repurpose antimicrobial drugs for AD, yielding promising results. However, the sole bacterial link to AD may be insufficiently understood. Bacterial amyloid presence in biofilms is well-documented, with certain bacterial proteins exacerbating amyloid formation while others inhibit it. For instance, Curli-specific gene protein C (CsgC) in E. coli suppresses curli amyloid formation. This review investigates the possibility of human CsgC-like proteins, identifying beta-2 microglobulin (β2M) and E3 ubiquitin ligases (E3s) as potential analogs that may influence amyloid degradation. We propose that nanoparticles (NPs) could serve as platforms to anchor these proteins, forming Amyloid Dissociating Bifunctional NanoChaperones (ADBiNaCs) with enhanced antiamyloidogenic activity. This innovative approach holds promise for novel AD treatment strategies, meriting further investigation into the role of bacterial and human amyloid-modulating proteins in AD pathology.
Additional Links: PMID-40247766
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Citation:
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@article {pmid40247766,
year = {2025},
author = {Randhawa, S and Saini, TC and Bathla, M and Teji, N and Acharya, A},
title = {Biofilm Biology to Brain Health: Harnessing Microbial Wisdom to Uncover Amyloid Dissociating Bifunctional Nano Chaperones for Alzheimer's Therapeutics.},
journal = {ACS chemical neuroscience},
volume = {},
number = {},
pages = {},
doi = {10.1021/acschemneuro.4c00868},
pmid = {40247766},
issn = {1948-7193},
abstract = {Microbial infections have long been implicated in the gut-brain link to Alzheimer's disease (AD). These infections may influence AD development either directly, through brain invasion, or indirectly via bacterial metabolites crossing the blood-brain-barrier (BBB) or interacting with the enteric nervous system (ENS). Such findings have inspired clinicians to repurpose antimicrobial drugs for AD, yielding promising results. However, the sole bacterial link to AD may be insufficiently understood. Bacterial amyloid presence in biofilms is well-documented, with certain bacterial proteins exacerbating amyloid formation while others inhibit it. For instance, Curli-specific gene protein C (CsgC) in E. coli suppresses curli amyloid formation. This review investigates the possibility of human CsgC-like proteins, identifying beta-2 microglobulin (β2M) and E3 ubiquitin ligases (E3s) as potential analogs that may influence amyloid degradation. We propose that nanoparticles (NPs) could serve as platforms to anchor these proteins, forming Amyloid Dissociating Bifunctional NanoChaperones (ADBiNaCs) with enhanced antiamyloidogenic activity. This innovative approach holds promise for novel AD treatment strategies, meriting further investigation into the role of bacterial and human amyloid-modulating proteins in AD pathology.},
}
RevDate: 2025-04-17
Dental adhesives incorporated with alkyl trimethyl ammonium bromide-loaded titanium oxide nanotubes for sustained bioactive and anti-biofilm protection.
Dental materials : official publication of the Academy of Dental Materials pii:S0109-5641(25)00595-0 [Epub ahead of print].
OBJECTIVES: This study aimed to formulate experimental dental adhesives with alkyl trimethyl ammonium bromide-loaded titanium oxide nanotubes (ntTiO2/ATAB) and evaluated their physicochemical properties, antimicrobial activity, mineral deposition, and cytotoxicity.
METHODS: ntTiO₂/ATAB was synthesized, characterized, and added into an experimental adhesive resin. The filler ntTiO₂/ATAB was added at 1, 2.5, and 5 wt% (G1 %, G2.5 %, G5 %) in the adhesive. A control group (G0 %) without ntTiO₂/ATAB was also prepared and used in all tests. The adhesives were analyzed for degree of conversion (DC%), softening in solvent, radiopacity, antibacterial activity against saliva-derived microcosm, mineral deposition capability, and cytotoxicity.
RESULTS: Analytical techniques, including TEM, FTIR, UV-Vis, and micro-Raman spectroscopy, confirmed the structure and chemical composition of the ntTiO₂/ATAB. A DC% over 60 % was observed for all groups, with no adverse impact on radiopacity or softening in solvent. Antibacterial testing indicated that increasing ntTiO₂/ATAB concentration led to reduced colony-forming units of critical microorganisms, with this effect sustained over a one-year aging period. Mineral deposition tests showed enhanced phosphate presence over the samples with higher ntTiO₂/ATAB concentrations. There were no statistical differences in human cell viability among groups.
SIGNIFICANCE: The dental adhesives formulated with ntTiO2/ATAB demonstrated suitable physical and chemical properties, including reliable bond strength to dentin previously tested. They also exhibited antibacterial effects against caries-related microorganisms even after aging, promoted bioactivity through mineral deposition, and showed no cytotoxicity against human cells. These adhesives represent a promising strategy to assist in reducing the risk of recurrent caries and preserve the material-dentin interface properties over time.
Additional Links: PMID-40246594
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PubMed:
Citation:
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@article {pmid40246594,
year = {2025},
author = {Garcia, IM and Araújo-Neto, VG and Balbinot, G and Souza, VS and Mokeem, L and Scholten, JD and Melo, MAS and Giannini, M and Collares, FM},
title = {Dental adhesives incorporated with alkyl trimethyl ammonium bromide-loaded titanium oxide nanotubes for sustained bioactive and anti-biofilm protection.},
journal = {Dental materials : official publication of the Academy of Dental Materials},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.dental.2025.04.002},
pmid = {40246594},
issn = {1879-0097},
abstract = {OBJECTIVES: This study aimed to formulate experimental dental adhesives with alkyl trimethyl ammonium bromide-loaded titanium oxide nanotubes (ntTiO2/ATAB) and evaluated their physicochemical properties, antimicrobial activity, mineral deposition, and cytotoxicity.
METHODS: ntTiO₂/ATAB was synthesized, characterized, and added into an experimental adhesive resin. The filler ntTiO₂/ATAB was added at 1, 2.5, and 5 wt% (G1 %, G2.5 %, G5 %) in the adhesive. A control group (G0 %) without ntTiO₂/ATAB was also prepared and used in all tests. The adhesives were analyzed for degree of conversion (DC%), softening in solvent, radiopacity, antibacterial activity against saliva-derived microcosm, mineral deposition capability, and cytotoxicity.
RESULTS: Analytical techniques, including TEM, FTIR, UV-Vis, and micro-Raman spectroscopy, confirmed the structure and chemical composition of the ntTiO₂/ATAB. A DC% over 60 % was observed for all groups, with no adverse impact on radiopacity or softening in solvent. Antibacterial testing indicated that increasing ntTiO₂/ATAB concentration led to reduced colony-forming units of critical microorganisms, with this effect sustained over a one-year aging period. Mineral deposition tests showed enhanced phosphate presence over the samples with higher ntTiO₂/ATAB concentrations. There were no statistical differences in human cell viability among groups.
SIGNIFICANCE: The dental adhesives formulated with ntTiO2/ATAB demonstrated suitable physical and chemical properties, including reliable bond strength to dentin previously tested. They also exhibited antibacterial effects against caries-related microorganisms even after aging, promoted bioactivity through mineral deposition, and showed no cytotoxicity against human cells. These adhesives represent a promising strategy to assist in reducing the risk of recurrent caries and preserve the material-dentin interface properties over time.},
}
RevDate: 2025-04-17
CmpDate: 2025-04-17
A new perspective on the simultaneous removal of nitrogen, tetracycline, and phosphorus by moving bed biofilm reactor under co-metabolic substances.
Journal of environmental sciences (China), 155:431-441.
With the burgeoning growth of aquaculture industry, high concentration of NH4[+]-N, phosphorus and tetracycline are the prevalent pollutants in aquaculture wastewater posing a significant health risk to aquatic organisms. Therefore, an effective method for treating aquaculture wastewater should be urgently explored. Simultaneous removal of NH4[+]-N, phosphorus, tetracycline, and chemical oxygen demand (COD) in aquaculture wastewater was developed by moving bed biofilm reactor (MBBR) under co-metabolic substances. The result showed that co-metabolism substances had different effects on MBBR performance, and 79.4 % of tetracycline, 68.2 % of NH4[+]-N, 61.3 % of total nitrogen, 88.3 % of COD, and 38.1 % of total phosphorus (TP) were synchronously removed with sodium acetate as a co-metabolic carbon source. Protein (PN), polysaccharide (PS), and electron transfer system activity were used to evaluate the MBBR performances, suggesting that PN/PS ratio was 1.48, 0.91, 1.07, 3.58, and 0.79 at phases I-V. Additionally, a mode of tetracycline degradation and TP removal was explored, and the cell apoptosis was evaluated by flow cytometry. The result suggested that 74 %, 83 %, and 83 % of tetracycline were degraded by extracellular extracts, intracellular extracts, and cell debris, and there was no difference between extracts and non-enzyme in TP removal. The ratio of viable and dead cells from biofilm reached 33.3 % and 7.68 % with sodium acetate as a co-metabolic carbon source. Furthermore, Proteobacteria and Bacteroidetes in biofilm were identified as the dominant phyla for tetracycline and nutrients removal. This study provides a new strategy for tetracycline and nutrients removal from aquaculture wastewater through co-metabolism.
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@article {pmid40246478,
year = {2025},
author = {Gao, Q and Zhu, F and Wang, M and Shao, S},
title = {A new perspective on the simultaneous removal of nitrogen, tetracycline, and phosphorus by moving bed biofilm reactor under co-metabolic substances.},
journal = {Journal of environmental sciences (China)},
volume = {155},
number = {},
pages = {431-441},
doi = {10.1016/j.jes.2024.09.012},
pmid = {40246478},
issn = {1001-0742},
mesh = {*Nitrogen/analysis/metabolism ; Biofilms ; *Bioreactors ; *Waste Disposal, Fluid/methods ; *Phosphorus/metabolism/analysis ; *Water Pollutants, Chemical/metabolism/analysis ; *Tetracycline/analysis/metabolism ; Wastewater/chemistry ; Aquaculture ; Biological Oxygen Demand Analysis ; },
abstract = {With the burgeoning growth of aquaculture industry, high concentration of NH4[+]-N, phosphorus and tetracycline are the prevalent pollutants in aquaculture wastewater posing a significant health risk to aquatic organisms. Therefore, an effective method for treating aquaculture wastewater should be urgently explored. Simultaneous removal of NH4[+]-N, phosphorus, tetracycline, and chemical oxygen demand (COD) in aquaculture wastewater was developed by moving bed biofilm reactor (MBBR) under co-metabolic substances. The result showed that co-metabolism substances had different effects on MBBR performance, and 79.4 % of tetracycline, 68.2 % of NH4[+]-N, 61.3 % of total nitrogen, 88.3 % of COD, and 38.1 % of total phosphorus (TP) were synchronously removed with sodium acetate as a co-metabolic carbon source. Protein (PN), polysaccharide (PS), and electron transfer system activity were used to evaluate the MBBR performances, suggesting that PN/PS ratio was 1.48, 0.91, 1.07, 3.58, and 0.79 at phases I-V. Additionally, a mode of tetracycline degradation and TP removal was explored, and the cell apoptosis was evaluated by flow cytometry. The result suggested that 74 %, 83 %, and 83 % of tetracycline were degraded by extracellular extracts, intracellular extracts, and cell debris, and there was no difference between extracts and non-enzyme in TP removal. The ratio of viable and dead cells from biofilm reached 33.3 % and 7.68 % with sodium acetate as a co-metabolic carbon source. Furthermore, Proteobacteria and Bacteroidetes in biofilm were identified as the dominant phyla for tetracycline and nutrients removal. This study provides a new strategy for tetracycline and nutrients removal from aquaculture wastewater through co-metabolism.},
}
MeSH Terms:
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*Nitrogen/analysis/metabolism
Biofilms
*Bioreactors
*Waste Disposal, Fluid/methods
*Phosphorus/metabolism/analysis
*Water Pollutants, Chemical/metabolism/analysis
*Tetracycline/analysis/metabolism
Wastewater/chemistry
Aquaculture
Biological Oxygen Demand Analysis
RevDate: 2025-04-17
Exploring the antifungal potential and action mechanism of pomegranate peel extract against Candida species in planktonic and biofilm conditions.
Microbial pathogenesis pii:S0882-4010(25)00321-3 [Epub ahead of print].
Candidiasis, a fungal infection caused by Candida spp., poses a growing clinical challenge due to the development of antifungal resistance. This study assessed the efficacy of dry crude pomegranate peel extract (DCPPE) as an antifungal agent against Candida infections (C. albicans, C. parapsilosis, C. krusei and C. glabrata) by investigating its effects on fungal growth, biofilm disruption, and fungal cell membrane integrity, as well as evaluating its safety regarding hemolysis at different concentrations. The DCPPE exhibited inhibitory activity against all tested Candida strains, with MIC of 1% (10 mg/mL). These results may be associated with the phenolic composition of the peel extract, which includes compounds like gallic acid, punicalagin A, punicalagin B, and ellagic acid. Furthermore, the DCPPE disrupted Candida biofilms and demonstrated safety with respect to hemolysis at concentrations up to 60 mg/mL. However, no evidence of a direct interaction with the fungal cell wall or ergosterol in the fungal membrane was found. Thus, our results highlight the potential of DCPPE as a promising alternative for the treatment of candidiasis. Nevertheless, further research is needed to fully clarify the underlying mechanisms and optimize its clinical efficacy.
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@article {pmid40246159,
year = {2025},
author = {Ferreira, NS and de Jesus Catten Moreno, T and Eduardo de Souza Duarte, C and Moreira, MG and Meza Ucella-Filho, JG and Ferreira, IM and Severi, JA and Costa Ignacchiti, MD and Oliveira Villanova, JC and Resende, JA},
title = {Exploring the antifungal potential and action mechanism of pomegranate peel extract against Candida species in planktonic and biofilm conditions.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107596},
doi = {10.1016/j.micpath.2025.107596},
pmid = {40246159},
issn = {1096-1208},
abstract = {Candidiasis, a fungal infection caused by Candida spp., poses a growing clinical challenge due to the development of antifungal resistance. This study assessed the efficacy of dry crude pomegranate peel extract (DCPPE) as an antifungal agent against Candida infections (C. albicans, C. parapsilosis, C. krusei and C. glabrata) by investigating its effects on fungal growth, biofilm disruption, and fungal cell membrane integrity, as well as evaluating its safety regarding hemolysis at different concentrations. The DCPPE exhibited inhibitory activity against all tested Candida strains, with MIC of 1% (10 mg/mL). These results may be associated with the phenolic composition of the peel extract, which includes compounds like gallic acid, punicalagin A, punicalagin B, and ellagic acid. Furthermore, the DCPPE disrupted Candida biofilms and demonstrated safety with respect to hemolysis at concentrations up to 60 mg/mL. However, no evidence of a direct interaction with the fungal cell wall or ergosterol in the fungal membrane was found. Thus, our results highlight the potential of DCPPE as a promising alternative for the treatment of candidiasis. Nevertheless, further research is needed to fully clarify the underlying mechanisms and optimize its clinical efficacy.},
}
RevDate: 2025-04-19
Moringa oleifera seed preparations containing the lectin WSMoL inhibit growth, cell aggregation, and biofilm production of Listeria monocytogenes.
Microbial pathogenesis, 204:107600 pii:S0882-4010(25)00325-0 [Epub ahead of print].
This work evaluated the antibacterial properties of aqueous extract (AE), protein-rich fraction (PF), and isolated water-soluble lectin (WSMoL) from Moringa oleifera Lam. seeds against the gram-positive bacterium Listeria monocytogenes, which causes listeriosis. Foodborne bacterial infections, which are facilitated by biofilm formation, pose significant public health threats. Listeriosis is an infection that involves bacteremia, meningitis, or meningoencephalitis. The strains N53-1 and EGD-e were assessed in this work. Bacteriostatic and bactericidal effects on planktonic cells were assessed by broth microdilution assay and flow cytometry. Possible combined effects with antibiotics (ciprofloxacin and cephalexin) were also determined, as well as the impact of all preparations on bacterial aggregation and biofilm formation. AE, PF and WSMoL presented minimum inhibitory concentration (MIC) ranging from 250 to 300 μg/mL for N53-1, and between 150 and 250 μg/mL for EGD-e. AE and WSMoL did not show bactericidal action but PF was bactericidal to EGD-e (minimal bactericidal concentration: 1500 μg/mL). AE, PF, and WSMoL demonstrated synergistic effects with ciprofloxacin, while AE and PF were synergic together with cephalexin. Moreover, AE, PF and WSMoL showed an inhibitory effect on aggregation of cells of both strains. At 0.97 μg/mL, WSMoL inhibited 95 % the biofilm formation by N53-1, while PF at 4.68 μg/mL elicited a biofilm inhibition of 87 % on the same strain. The data stimulate more studies assessing the potential of crude and purified preparations from M. oleifera containing the lectin WSMoL to combat the causer of listeriosis, as synergistic agents and as aggregation inhibitors.
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@article {pmid40246157,
year = {2025},
author = {da Silva, WSFL and Amorim, PK and Ferreira, GRS and Alves, RRV and da Silva, CES and Dos Santos, PÉM and Guedes Paiva, PM and Ingmer, H and da Silva, SP and da Silva, PM and Napoleão, TH},
title = {Moringa oleifera seed preparations containing the lectin WSMoL inhibit growth, cell aggregation, and biofilm production of Listeria monocytogenes.},
journal = {Microbial pathogenesis},
volume = {204},
number = {},
pages = {107600},
doi = {10.1016/j.micpath.2025.107600},
pmid = {40246157},
issn = {1096-1208},
abstract = {This work evaluated the antibacterial properties of aqueous extract (AE), protein-rich fraction (PF), and isolated water-soluble lectin (WSMoL) from Moringa oleifera Lam. seeds against the gram-positive bacterium Listeria monocytogenes, which causes listeriosis. Foodborne bacterial infections, which are facilitated by biofilm formation, pose significant public health threats. Listeriosis is an infection that involves bacteremia, meningitis, or meningoencephalitis. The strains N53-1 and EGD-e were assessed in this work. Bacteriostatic and bactericidal effects on planktonic cells were assessed by broth microdilution assay and flow cytometry. Possible combined effects with antibiotics (ciprofloxacin and cephalexin) were also determined, as well as the impact of all preparations on bacterial aggregation and biofilm formation. AE, PF and WSMoL presented minimum inhibitory concentration (MIC) ranging from 250 to 300 μg/mL for N53-1, and between 150 and 250 μg/mL for EGD-e. AE and WSMoL did not show bactericidal action but PF was bactericidal to EGD-e (minimal bactericidal concentration: 1500 μg/mL). AE, PF, and WSMoL demonstrated synergistic effects with ciprofloxacin, while AE and PF were synergic together with cephalexin. Moreover, AE, PF and WSMoL showed an inhibitory effect on aggregation of cells of both strains. At 0.97 μg/mL, WSMoL inhibited 95 % the biofilm formation by N53-1, while PF at 4.68 μg/mL elicited a biofilm inhibition of 87 % on the same strain. The data stimulate more studies assessing the potential of crude and purified preparations from M. oleifera containing the lectin WSMoL to combat the causer of listeriosis, as synergistic agents and as aggregation inhibitors.},
}
RevDate: 2025-04-17
Aerobic biofilm systems outperform anaerobic and anoxic regimes in 2,4-dimethylphenol degradation: Microbial synergy and metabolic mechanisms.
Journal of environmental management, 382:125408 pii:S0301-4797(25)01384-2 [Epub ahead of print].
The efficient biodegradation of 2,4-dimethylphenol (2,4-DMP), a toxic and recalcitrant phenolic pollutant, remains a critical challenge in wastewater treatment, with ongoing debate regarding the optimal dissolved oxygen (DO) regime for biofilm-based systems. To resolve this, four biofilm reactors-anaerobic (R1), anoxic (R2), microaerobic (R3), and aerobic (R4)-were operated under a DO gradient (0.3-8.0 mg/L). When influent 2,4-DMP concentrations increased from 25 to 300 mg/L, removal efficiencies declined significantly in R1-R3 (9.0 %, 44.8 %, and 58.8 %, respectively), whereas R4 maintained 100 % removal regardless of loading. Rapid degradation occurred within 8-16 h in R4, correlating with DO consumption from 8.0 to 5.0 mg/L. Aerobic conditions eliminated dependence on extracellular polymeric substances (EPS) for pollutant sequestration, as complete mineralization negated intermediate accumulation. Microbial analysis revealed Zoogloea (18.92 % abundance), Prosthecobacter, and Ferruginibacter as keystone aerobic bacteria, encoding aromatic ring-hydroxylating dioxygenases (RHDs) for 2,4-DMP hydroxylation and β-ketoadipate pathway activation. Concurrently, fungal genera Cutaneotrichosporon (74.50 %) and Kalenjinia were enriched in R4, contributing laccase-mediated ring cleavage. Synergy between bacterial oxidative pathways and fungal ligninolytic systems enabled sustained COD removal (95.54 %) without biofilm destabilization. These findings conclusively demonstrate aerobic biofilms' superiority in 2,4-DMP treatment, driven by metabolic completeness, energy-efficient respiration, and cross-kingdom functional partitioning.
Additional Links: PMID-40245737
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PubMed:
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@article {pmid40245737,
year = {2025},
author = {Yang, Y and Wang, Y and Shi, J},
title = {Aerobic biofilm systems outperform anaerobic and anoxic regimes in 2,4-dimethylphenol degradation: Microbial synergy and metabolic mechanisms.},
journal = {Journal of environmental management},
volume = {382},
number = {},
pages = {125408},
doi = {10.1016/j.jenvman.2025.125408},
pmid = {40245737},
issn = {1095-8630},
abstract = {The efficient biodegradation of 2,4-dimethylphenol (2,4-DMP), a toxic and recalcitrant phenolic pollutant, remains a critical challenge in wastewater treatment, with ongoing debate regarding the optimal dissolved oxygen (DO) regime for biofilm-based systems. To resolve this, four biofilm reactors-anaerobic (R1), anoxic (R2), microaerobic (R3), and aerobic (R4)-were operated under a DO gradient (0.3-8.0 mg/L). When influent 2,4-DMP concentrations increased from 25 to 300 mg/L, removal efficiencies declined significantly in R1-R3 (9.0 %, 44.8 %, and 58.8 %, respectively), whereas R4 maintained 100 % removal regardless of loading. Rapid degradation occurred within 8-16 h in R4, correlating with DO consumption from 8.0 to 5.0 mg/L. Aerobic conditions eliminated dependence on extracellular polymeric substances (EPS) for pollutant sequestration, as complete mineralization negated intermediate accumulation. Microbial analysis revealed Zoogloea (18.92 % abundance), Prosthecobacter, and Ferruginibacter as keystone aerobic bacteria, encoding aromatic ring-hydroxylating dioxygenases (RHDs) for 2,4-DMP hydroxylation and β-ketoadipate pathway activation. Concurrently, fungal genera Cutaneotrichosporon (74.50 %) and Kalenjinia were enriched in R4, contributing laccase-mediated ring cleavage. Synergy between bacterial oxidative pathways and fungal ligninolytic systems enabled sustained COD removal (95.54 %) without biofilm destabilization. These findings conclusively demonstrate aerobic biofilms' superiority in 2,4-DMP treatment, driven by metabolic completeness, energy-efficient respiration, and cross-kingdom functional partitioning.},
}
RevDate: 2025-04-17
Characterization of proteins present in the biofilm matrix and outer membrane vesicles of Histophilus somni during iron-sufficient and iron-restricted growth: identification of potential protective antigens through in silico analyses.
mBio [Epub ahead of print].
There is limited efficacy in vaccines currently available to prevent some animal diseases of bacterial origin, such as bovine respiratory disease caused by Histophilus somni. Protective efficacy can potentially be improved if bacterial antigens that are expressed in the host are included in vaccines. During H. somni infection in the bovine host, biofilms become established, and the availability of essential iron is restricted. To investigate further, the protein composition of spontaneously released outer membrane vesicles (OMVs) during iron-sufficient and iron-restricted growth and the proteins expressed in the biofilm matrix were analyzed and compared. Proteomic analysis revealed a dramatic physiological change in H. somni as it transitioned from the planktonic form to the biofilm mode of growth. All transferrin-binding proteins (Tbps) previously identified in H. somni were detected in the OMVs, suggesting that OMVs could induce antibodies to these proteins. Two TbpA-like proteins and seven total proteins were present in the OMVs only when iron was restricted, indicating the expression of these Tbps was differentially regulated. More proteins associated with quorum-sensing (QS) signaling were detected in the biofilm matrix compared with proteins in the OMVs, supporting a link between QS and biofilm formation. Proteins ACA31267.1 (OmpA) and ACA32419.1 (TonB-dependent receptor) were present in the OMV and biofilm matrix and predicted to be potential protective antigens using an immuno-bioinformatic approach. Overall, the results support the development of novel vaccines that contain OMVs obtained from bacteria grown to simulate the in vivo environment, and possibly biofilm matrix, to prevent diseases caused by bacterial pathogens.IMPORTANCEBovine respiratory disease (BRD) is the most economically important disease affecting the cattle industry. Available BRD vaccines consist of killed bacteria but are not very effective. Poor vaccine efficacy may be because the phenotype of bacteria in the host differs from the phenotype of cultured bacteria. Following host infection, virulent bacteria can express transferrin-binding proteins (Tbps) not expressed in culture medium but are required to sequester iron from host proteins. During chronic infections, such as BRD, bacteria can form a biofilm consisting of novel protein and polysaccharide antigens. The unique proteins expressed on outer membrane vesicles (OMVs) of Histophilus somni (a BRD pathogen) in the absence of iron and as a biofilm were identified and characterized. At least two TbpA-like proteins were expressed in OMVs only under iron-limiting conditions. Quorum-sensing-associated proteins were identified in the H. somni biofilm matrix. In silico analysis identified potential protein targets for vaccine development.
Additional Links: PMID-40243366
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PubMed:
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@article {pmid40243366,
year = {2025},
author = {Lee, Y-J and Abdullah, M and Chang, Y-F and Sudani, HA and Inzana, TJ},
title = {Characterization of proteins present in the biofilm matrix and outer membrane vesicles of Histophilus somni during iron-sufficient and iron-restricted growth: identification of potential protective antigens through in silico analyses.},
journal = {mBio},
volume = {},
number = {},
pages = {e0064425},
doi = {10.1128/mbio.00644-25},
pmid = {40243366},
issn = {2150-7511},
abstract = {There is limited efficacy in vaccines currently available to prevent some animal diseases of bacterial origin, such as bovine respiratory disease caused by Histophilus somni. Protective efficacy can potentially be improved if bacterial antigens that are expressed in the host are included in vaccines. During H. somni infection in the bovine host, biofilms become established, and the availability of essential iron is restricted. To investigate further, the protein composition of spontaneously released outer membrane vesicles (OMVs) during iron-sufficient and iron-restricted growth and the proteins expressed in the biofilm matrix were analyzed and compared. Proteomic analysis revealed a dramatic physiological change in H. somni as it transitioned from the planktonic form to the biofilm mode of growth. All transferrin-binding proteins (Tbps) previously identified in H. somni were detected in the OMVs, suggesting that OMVs could induce antibodies to these proteins. Two TbpA-like proteins and seven total proteins were present in the OMVs only when iron was restricted, indicating the expression of these Tbps was differentially regulated. More proteins associated with quorum-sensing (QS) signaling were detected in the biofilm matrix compared with proteins in the OMVs, supporting a link between QS and biofilm formation. Proteins ACA31267.1 (OmpA) and ACA32419.1 (TonB-dependent receptor) were present in the OMV and biofilm matrix and predicted to be potential protective antigens using an immuno-bioinformatic approach. Overall, the results support the development of novel vaccines that contain OMVs obtained from bacteria grown to simulate the in vivo environment, and possibly biofilm matrix, to prevent diseases caused by bacterial pathogens.IMPORTANCEBovine respiratory disease (BRD) is the most economically important disease affecting the cattle industry. Available BRD vaccines consist of killed bacteria but are not very effective. Poor vaccine efficacy may be because the phenotype of bacteria in the host differs from the phenotype of cultured bacteria. Following host infection, virulent bacteria can express transferrin-binding proteins (Tbps) not expressed in culture medium but are required to sequester iron from host proteins. During chronic infections, such as BRD, bacteria can form a biofilm consisting of novel protein and polysaccharide antigens. The unique proteins expressed on outer membrane vesicles (OMVs) of Histophilus somni (a BRD pathogen) in the absence of iron and as a biofilm were identified and characterized. At least two TbpA-like proteins were expressed in OMVs only under iron-limiting conditions. Quorum-sensing-associated proteins were identified in the H. somni biofilm matrix. In silico analysis identified potential protein targets for vaccine development.},
}
RevDate: 2025-04-17
Protein Homeostasis Impairment Alters Phenotypic Heterogeneity of Biofilm Communities.
Molecular microbiology [Epub ahead of print].
Biofilms are highly organized, cooperating communities of microorganisms encased in a self-produced extracellular matrix, providing resilience against external stress such as antimicrobial agents and host defenses. A hallmark of biofilms is their phenotypic heterogeneity, which enhances the overall growth and survival of the community. In this study, we demonstrate that removing the dnaK and tig genes encoding the core molecular chaperones DnaK (Hsp70 homolog) and Trigger factor disrupted protein homeostasis in Bacillus subtilis and resulted in the formation of an extremely mucoid biofilm with aberrant architecture, compromised structural integrity, and altered phenotypic heterogeneity. These changes include a large reduction in the motile subpopulation and an overrepresentation of matrix producers and endospores. Overproduction of poly-γ-glutamic acid contributed crucially to the mucoid phenotype and aberrant biofilm architecture. Homeostasis impairment, triggered by elevated temperatures, in wild-type cells led to mucoid and aberrant biofilm phenotypes similar to those observed in strains lacking both dnaK and tig. Our findings show that disruption of protein homeostasis, whether due to the absence of molecular chaperones or because of environmental factors, severely changes biofilm features.
Additional Links: PMID-40243034
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@article {pmid40243034,
year = {2025},
author = {Matavacas, J and von Wachenfeldt, C},
title = {Protein Homeostasis Impairment Alters Phenotypic Heterogeneity of Biofilm Communities.},
journal = {Molecular microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/mmi.15366},
pmid = {40243034},
issn = {1365-2958},
support = {2023-05271//Vetenskapsrådet/ ; //Kungliga Fysiografiska Sällskapet i Lund/ ; //Jörgen Lindström's Foundation/ ; },
abstract = {Biofilms are highly organized, cooperating communities of microorganisms encased in a self-produced extracellular matrix, providing resilience against external stress such as antimicrobial agents and host defenses. A hallmark of biofilms is their phenotypic heterogeneity, which enhances the overall growth and survival of the community. In this study, we demonstrate that removing the dnaK and tig genes encoding the core molecular chaperones DnaK (Hsp70 homolog) and Trigger factor disrupted protein homeostasis in Bacillus subtilis and resulted in the formation of an extremely mucoid biofilm with aberrant architecture, compromised structural integrity, and altered phenotypic heterogeneity. These changes include a large reduction in the motile subpopulation and an overrepresentation of matrix producers and endospores. Overproduction of poly-γ-glutamic acid contributed crucially to the mucoid phenotype and aberrant biofilm architecture. Homeostasis impairment, triggered by elevated temperatures, in wild-type cells led to mucoid and aberrant biofilm phenotypes similar to those observed in strains lacking both dnaK and tig. Our findings show that disruption of protein homeostasis, whether due to the absence of molecular chaperones or because of environmental factors, severely changes biofilm features.},
}
RevDate: 2025-04-18
Development of a Novel PCB-Degrading Biofilm Enriched Biochar Encapsulated with Sol-Gel: A Protective Layer to Sustain Biodegradation Activity.
ACS ES&T engineering, 5(4):883-898.
Paraburkholderia xenovorans LB400 biofilms hold the potential to degrade PCBs in contaminated sediment. Nevertheless, unfavorable environmental conditions (e.g., salinity, temperature, and shear force) can interfere with biofilm stability and affect biodegradation potential. Sol-gel encapsulation has been used to protect planktonic cell function due to high material stability and absence of cell washout but has not been employed for biofilm protection. Our study is the first to develop sol-gel application on biofilm-enriched black carbons and evaluate efficacy for prolonging biodegradation potential. We systematically tuned multiple sol-gel recipes to coat biofilms and measured the impact of the sol-gel coating on cell survival and pollutant degradation. The developed sol-gel completely encapsulated biofilm-enriched black carbons and produced both high porosity and appropriate pore size that allowed pollutant transfer from the surrounding environment to the biofilms. The sol-gel maintained physical integrity under saline conditions (simulating marine and estuary sediments) and continuously applied shear force. Additionally, the encapsulated biofilms degraded benzoate, a proof-of-concept organic molecule, and extended biofilm attachment and cell viability for over three months without a carbon and energy source. Our study demonstrates that sol-gel helps sustain PCB-degrading biofilms under environmentally relevant conditions. This novel sol-gel application can potentially improve the bioaugmentation effectiveness and enhance degradation of environmental pollutants.
Additional Links: PMID-40242783
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@article {pmid40242783,
year = {2025},
author = {Dong, Q and Mattes, TE and LeFevre, GH},
title = {Development of a Novel PCB-Degrading Biofilm Enriched Biochar Encapsulated with Sol-Gel: A Protective Layer to Sustain Biodegradation Activity.},
journal = {ACS ES&T engineering},
volume = {5},
number = {4},
pages = {883-898},
pmid = {40242783},
issn = {2690-0645},
abstract = {Paraburkholderia xenovorans LB400 biofilms hold the potential to degrade PCBs in contaminated sediment. Nevertheless, unfavorable environmental conditions (e.g., salinity, temperature, and shear force) can interfere with biofilm stability and affect biodegradation potential. Sol-gel encapsulation has been used to protect planktonic cell function due to high material stability and absence of cell washout but has not been employed for biofilm protection. Our study is the first to develop sol-gel application on biofilm-enriched black carbons and evaluate efficacy for prolonging biodegradation potential. We systematically tuned multiple sol-gel recipes to coat biofilms and measured the impact of the sol-gel coating on cell survival and pollutant degradation. The developed sol-gel completely encapsulated biofilm-enriched black carbons and produced both high porosity and appropriate pore size that allowed pollutant transfer from the surrounding environment to the biofilms. The sol-gel maintained physical integrity under saline conditions (simulating marine and estuary sediments) and continuously applied shear force. Additionally, the encapsulated biofilms degraded benzoate, a proof-of-concept organic molecule, and extended biofilm attachment and cell viability for over three months without a carbon and energy source. Our study demonstrates that sol-gel helps sustain PCB-degrading biofilms under environmentally relevant conditions. This novel sol-gel application can potentially improve the bioaugmentation effectiveness and enhance degradation of environmental pollutants.},
}
RevDate: 2025-04-18
Size matters: Anaerobic granules exhibit distinct ecological and physico-chemical gradients across biofilm size.
Environmental science and ecotechnology, 25:100561.
Anaerobic biological decomposition of organic matter is ubiquitous in Nature wherever anaerobic environments prevail, and is catalysed by hydrolytic, fermentative, acetogenic, methanogenic, and various other groups. It is also harnessed in innovative ways in engineered systems that may rely on small (0.1-4.0 mm), spherical, anaerobic granules. These biofilms are crucial to the operational success of a range of widely applied engineered-ecosystems designed for wastewater treatment. The structure and function of granule microbiomes underpin their utility. Here, granules were separated into ten size fractions (proxies for age), hypothesizing that small granules are 'young' and larger ones are 'old'. Gradients were observed across size in terms of volatile solids, density, settleability, biofilm morphology, methanogenic activity, and profiles of extracellular polymeric substances, suggesting ongoing development of physico-chemical characteristics as granules develop. Short-read amplicon sequencing indicated a negative relationship between granule size and community diversity. Furthermore, as size increased, the methanogenic archaea dominated the microbiome. Small granules were found to harbour a sub-group of highly specific taxa, and the identification of generalists and specialists may point to substantial resilience of the microbiome. The findings of this study indicate opportunities for precision management of wastewater treatment systems. They suggest that size is an important indicator for aggregate utility - size may, indeed, determine many of the characteristics of both the individual-granule microbiomes and the overall function of a wastewater treatment system.
Additional Links: PMID-40242235
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Citation:
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@article {pmid40242235,
year = {2025},
author = {Trego, A and Morabito, C and Bourven, I and Guibaud, G and O'Flaherty, V and Collins, G and Ijaz, UZ},
title = {Size matters: Anaerobic granules exhibit distinct ecological and physico-chemical gradients across biofilm size.},
journal = {Environmental science and ecotechnology},
volume = {25},
number = {},
pages = {100561},
pmid = {40242235},
issn = {2666-4984},
abstract = {Anaerobic biological decomposition of organic matter is ubiquitous in Nature wherever anaerobic environments prevail, and is catalysed by hydrolytic, fermentative, acetogenic, methanogenic, and various other groups. It is also harnessed in innovative ways in engineered systems that may rely on small (0.1-4.0 mm), spherical, anaerobic granules. These biofilms are crucial to the operational success of a range of widely applied engineered-ecosystems designed for wastewater treatment. The structure and function of granule microbiomes underpin their utility. Here, granules were separated into ten size fractions (proxies for age), hypothesizing that small granules are 'young' and larger ones are 'old'. Gradients were observed across size in terms of volatile solids, density, settleability, biofilm morphology, methanogenic activity, and profiles of extracellular polymeric substances, suggesting ongoing development of physico-chemical characteristics as granules develop. Short-read amplicon sequencing indicated a negative relationship between granule size and community diversity. Furthermore, as size increased, the methanogenic archaea dominated the microbiome. Small granules were found to harbour a sub-group of highly specific taxa, and the identification of generalists and specialists may point to substantial resilience of the microbiome. The findings of this study indicate opportunities for precision management of wastewater treatment systems. They suggest that size is an important indicator for aggregate utility - size may, indeed, determine many of the characteristics of both the individual-granule microbiomes and the overall function of a wastewater treatment system.},
}
RevDate: 2025-04-18
Biofilm-mediated mass transfer of sorbed benzo[a]pyrene from polyethylene to seawater.
Environmental pollution (Barking, Essex : 1987), 374:126257 pii:S0269-7491(25)00630-X [Epub ahead of print].
Plastic waste, including microplastics (MPs), often serves as a carrier for hydrophobic organic contaminants (HOCs) and additives in aquatic environments. However, little is known about the fate of contaminants in plastics, especially under the influence of biofilm in field conditions. In this study, polyethylene (PE) was pre-sorbed with varying concentrations of benzo[a]pyrene (BaP), a non-polar contaminant, and deployed in situ to study desorption kinetics under natural biofilm colonization. Based on the desorption kinetics of BaP from PE, a mass transfer model was developed to describe the desorption of non-polar contaminants from PE under the influence of biofilm formation. This study proved that biofilm, acting as an intermediary between plastics and the aquatic environment, did not serve as a sink for plastic-sorbed BaP, but accelerated the desorption process of BaP by reducing the partition coefficient between the plastic and the boundary layer. Furthermore, based on our developed model (IABL-ODD), the effects of biofilm on the fate of other non-polar and weakly polar contaminants in PE were predicted. This study highlights the influence of biofilm on the desorption of hydrophobic contaminants from plastics in field conditions and also informs future work on more relevant processes such as additive leaching.
Additional Links: PMID-40239938
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PubMed:
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@article {pmid40239938,
year = {2025},
author = {Liu, H and Ma, Y and Xiao, J and Zhang, Y and Li, Y and Shen, A and Niu, Z and Chen, Q and Chen, B},
title = {Biofilm-mediated mass transfer of sorbed benzo[a]pyrene from polyethylene to seawater.},
journal = {Environmental pollution (Barking, Essex : 1987)},
volume = {374},
number = {},
pages = {126257},
doi = {10.1016/j.envpol.2025.126257},
pmid = {40239938},
issn = {1873-6424},
abstract = {Plastic waste, including microplastics (MPs), often serves as a carrier for hydrophobic organic contaminants (HOCs) and additives in aquatic environments. However, little is known about the fate of contaminants in plastics, especially under the influence of biofilm in field conditions. In this study, polyethylene (PE) was pre-sorbed with varying concentrations of benzo[a]pyrene (BaP), a non-polar contaminant, and deployed in situ to study desorption kinetics under natural biofilm colonization. Based on the desorption kinetics of BaP from PE, a mass transfer model was developed to describe the desorption of non-polar contaminants from PE under the influence of biofilm formation. This study proved that biofilm, acting as an intermediary between plastics and the aquatic environment, did not serve as a sink for plastic-sorbed BaP, but accelerated the desorption process of BaP by reducing the partition coefficient between the plastic and the boundary layer. Furthermore, based on our developed model (IABL-ODD), the effects of biofilm on the fate of other non-polar and weakly polar contaminants in PE were predicted. This study highlights the influence of biofilm on the desorption of hydrophobic contaminants from plastics in field conditions and also informs future work on more relevant processes such as additive leaching.},
}
RevDate: 2025-04-16
Large-sized aerobic granular biofilm: stable biotechnology to improve nitrogen removal and reduce sludge yield.
Bioresource technology pii:S0960-8524(25)00509-7 [Epub ahead of print].
Three parallel sequencing batch reactors (control, small-sized polyurethane sponge (PUS) (3.0 mm), and large-sized PUS (10.0 mm)) were used to investigate aerobic granular biofilm (AGB) characteristics. Results show that 10.0 mm PUS facilitated rapid formation of large-sized AGB (AGBL), which exhibited higher biomass concentration (8.5 g/L) and faster settling velocity (69.2-159.3 m/h) than aerobic granular sludge (AGS) (3.2 g/L and 38.6-80.0 m/h). The AGBL system also maintained long-term structural stability with a lower instability coefficient (0.004-0.018 min[-1]) than AGS (0.053-0.090 min[-1]). Additionally, during long-term operation, the AGBL system achieved excellent removal efficiencies for NH4[+]-N (99.6 ± 0.4 %) and total nitrogen (92.3 ± 2.6 %), and exhibited a lower sludge yield (0.05 gVSS/gCOD) than AGS (0.14 gVSS/gCOD). The larger size and compact structure of AGBL increased anoxic/anaerobic zones, enriching denitrifying and hydrolytic/fermentative bacteria. These findings highlight AGBL with large PUS as a more promising biotechnology for practical applications than conventional AGS.
Additional Links: PMID-40239902
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@article {pmid40239902,
year = {2025},
author = {Ma, H and Chen, S and Lv, L and Ye, Z and Yang, J and Wang, B and Zou, J and Li, J and Ganigué, R},
title = {Large-sized aerobic granular biofilm: stable biotechnology to improve nitrogen removal and reduce sludge yield.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {132543},
doi = {10.1016/j.biortech.2025.132543},
pmid = {40239902},
issn = {1873-2976},
abstract = {Three parallel sequencing batch reactors (control, small-sized polyurethane sponge (PUS) (3.0 mm), and large-sized PUS (10.0 mm)) were used to investigate aerobic granular biofilm (AGB) characteristics. Results show that 10.0 mm PUS facilitated rapid formation of large-sized AGB (AGBL), which exhibited higher biomass concentration (8.5 g/L) and faster settling velocity (69.2-159.3 m/h) than aerobic granular sludge (AGS) (3.2 g/L and 38.6-80.0 m/h). The AGBL system also maintained long-term structural stability with a lower instability coefficient (0.004-0.018 min[-1]) than AGS (0.053-0.090 min[-1]). Additionally, during long-term operation, the AGBL system achieved excellent removal efficiencies for NH4[+]-N (99.6 ± 0.4 %) and total nitrogen (92.3 ± 2.6 %), and exhibited a lower sludge yield (0.05 gVSS/gCOD) than AGS (0.14 gVSS/gCOD). The larger size and compact structure of AGBL increased anoxic/anaerobic zones, enriching denitrifying and hydrolytic/fermentative bacteria. These findings highlight AGBL with large PUS as a more promising biotechnology for practical applications than conventional AGS.},
}
RevDate: 2025-04-16
Flocculent sludge outperforms filler biofilm for high salinity oilfield produced water treatment: Performance, metabolic pathways, and microbial communities.
Journal of hazardous materials, 492:138217 pii:S0304-3894(25)01132-X [Epub ahead of print].
High-salinity oilfield produced water (OPW) posed significant challenges for biological treatment due to its complex composition and toxic effects. This study systematically compared the performance of heterotrophic ammonia assimilation (HAA) constructed by three filler biofilms (soft fiber filler, cylindrical filler, and sponge filler) and a flocculent sludge in degrading petroleum hydrocarbons. The dynamic mixing and suspended-growth nature of flocculent sludge ensured efficient substrate distribution and microbial interaction, enhancing treatment performance of NH4[+]-N, COD and total petroleum hydrocarbons. Due to mass transfer limitations and ecological specialization, the impact loading capacity of the HAA biofilm reactors to actual OPW were limited compared with flocculent sludge. Halomonas and Marinobacter were enriched in four bioreactors as the main forces of halotolerant hydrocarbon degraders and nitrogen assimilation main forces. The flocculent sludge showed a stronger microbial network, increased functional gene abundance, and higher enzymatic activity for key degradation pathways compared to biofilm systems. KEGG-based gene and enzyme activity analysis revealed the superior metabolic potential of flocculent sludge for degrading recalcitrant hydrocarbons in high-salinity oilfield-produced water, including alkanes, aromatics and polycyclic aromatic hydrocarbons. These findings highlight the superior potential of flocculent sludge system for treating high-salinity OPW through efficient microbial and metabolic interactions.
Additional Links: PMID-40239531
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PubMed:
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@article {pmid40239531,
year = {2025},
author = {Zhao, C and Zhang, W and Guo, Y and Zhang, M and Han, F and Lei, J and Zhou, W},
title = {Flocculent sludge outperforms filler biofilm for high salinity oilfield produced water treatment: Performance, metabolic pathways, and microbial communities.},
journal = {Journal of hazardous materials},
volume = {492},
number = {},
pages = {138217},
doi = {10.1016/j.jhazmat.2025.138217},
pmid = {40239531},
issn = {1873-3336},
abstract = {High-salinity oilfield produced water (OPW) posed significant challenges for biological treatment due to its complex composition and toxic effects. This study systematically compared the performance of heterotrophic ammonia assimilation (HAA) constructed by three filler biofilms (soft fiber filler, cylindrical filler, and sponge filler) and a flocculent sludge in degrading petroleum hydrocarbons. The dynamic mixing and suspended-growth nature of flocculent sludge ensured efficient substrate distribution and microbial interaction, enhancing treatment performance of NH4[+]-N, COD and total petroleum hydrocarbons. Due to mass transfer limitations and ecological specialization, the impact loading capacity of the HAA biofilm reactors to actual OPW were limited compared with flocculent sludge. Halomonas and Marinobacter were enriched in four bioreactors as the main forces of halotolerant hydrocarbon degraders and nitrogen assimilation main forces. The flocculent sludge showed a stronger microbial network, increased functional gene abundance, and higher enzymatic activity for key degradation pathways compared to biofilm systems. KEGG-based gene and enzyme activity analysis revealed the superior metabolic potential of flocculent sludge for degrading recalcitrant hydrocarbons in high-salinity oilfield-produced water, including alkanes, aromatics and polycyclic aromatic hydrocarbons. These findings highlight the superior potential of flocculent sludge system for treating high-salinity OPW through efficient microbial and metabolic interactions.},
}
RevDate: 2025-04-16
Study on adsorption and desorption characteristics of lead pollution by biofilm in drinking water pipeline from multi-factor perspective.
Journal of hazardous materials, 492:138284 pii:S0304-3894(25)01199-9 [Epub ahead of print].
This study investigates lead adsorption and desorption behaviors in biofilms on drinking water pipeline materials (PVC, 304 stainless steel, copper) under varying flow rate, pH, and residual chlorine. Biofilms on stainless steel exhibited the highest adsorption capacity (450.81 μmol/m[2]), whereas PVC biofilms had the greatest desorption potential (25.30 μmol/m[2]). Optimal lead adsorption occurred at neutral pH (7.5), low flow velocity (0.10 m/s), and moderate chlorine concentration (0.3 mg/L). Optimal lead adsorption occurred at neutral pH (7.5), low flow velocity (0.10 m/s), and moderate chlorine concentration (0.3 mg/L). In contrast, higher flow velocities, acidic conditions, and elevated chlorine levels promoted desorption or inhibited interactions. PVC biofilms exhibited the highest biomass (1.58 × 10[6] CFU/cm[2]) and extracellular polymeric substances (EPS) (348 mg/m[2]), correlating with increased lead adsorption. Functional analysis revealed a higher abundance of ion-transport-related (functions associated with the movement of ions such as heavy metals across microbial cell membranes) functions in PVC biofilms, contributing to enhanced stability. The study offers valuable insights for optimizing pipe material selection and operational strategies to reduce lead contamination in water systems.
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@article {pmid40239519,
year = {2025},
author = {Bian, Y and Guo, X and He, X and Xu, R and Yang, Z and Chen, R and Sheng, K and Zhang, Y},
title = {Study on adsorption and desorption characteristics of lead pollution by biofilm in drinking water pipeline from multi-factor perspective.},
journal = {Journal of hazardous materials},
volume = {492},
number = {},
pages = {138284},
doi = {10.1016/j.jhazmat.2025.138284},
pmid = {40239519},
issn = {1873-3336},
abstract = {This study investigates lead adsorption and desorption behaviors in biofilms on drinking water pipeline materials (PVC, 304 stainless steel, copper) under varying flow rate, pH, and residual chlorine. Biofilms on stainless steel exhibited the highest adsorption capacity (450.81 μmol/m[2]), whereas PVC biofilms had the greatest desorption potential (25.30 μmol/m[2]). Optimal lead adsorption occurred at neutral pH (7.5), low flow velocity (0.10 m/s), and moderate chlorine concentration (0.3 mg/L). Optimal lead adsorption occurred at neutral pH (7.5), low flow velocity (0.10 m/s), and moderate chlorine concentration (0.3 mg/L). In contrast, higher flow velocities, acidic conditions, and elevated chlorine levels promoted desorption or inhibited interactions. PVC biofilms exhibited the highest biomass (1.58 × 10[6] CFU/cm[2]) and extracellular polymeric substances (EPS) (348 mg/m[2]), correlating with increased lead adsorption. Functional analysis revealed a higher abundance of ion-transport-related (functions associated with the movement of ions such as heavy metals across microbial cell membranes) functions in PVC biofilms, contributing to enhanced stability. The study offers valuable insights for optimizing pipe material selection and operational strategies to reduce lead contamination in water systems.},
}
RevDate: 2025-04-16
Evaluation of Biofilm Production and Antibiotic Resistance/Susceptibility Profiles of Pseudomonas spp. Isolated from Milk and Dairy Products.
Foods (Basel, Switzerland), 14(7): pii:foods14071105.
Dairy-borne Pseudomonas spp., known for causing spoilage, may also exhibit antibiotic resistance and form biofilms, enhancing their persistence in dairy environments and contaminating final products. This study examined biofilm formation and antibiotic resistance in 106 Pseudomonas spp. strains isolated from milk, whey, and spoiled dairy products. Phylogenetic analysis (based on partial ileS sequences) grouped most strains within the P. fluorescens group, clustering into the P. fluorescens, P. gessardii, P. koorensis, and P. fragi subgroups. Biofilm formation in polystyrene microplates was assessed at 6 °C and 25 °C by crystal violet staining. After 48 h, 72% and 65% of Pseudomonas strains formed biofilms at 6 °C and 25 °C, respectively, with higher biomass production at 6 °C. High biofilm producers included most P. fluorescens, P. shahriarae, P. salmasensis, P. atacamensis, P. gessardii, P. koreensis, and P. lundensis strains. The adnA gene, associated with biofilm formation, was detected in 60% of the biofilm producers, but was absent in P. fragi, P. lundensis, P. weihenstephanensis, and P. putida. Antibiotic susceptibility was tested using the disk diffusion method. All strains were susceptible to amikacin and tobramycin; however, 73% of the strains were resistant to aztreonam, 28% to imipenem and doripenem, 19% to ceftazidime, 13% to meropenem, and 7% to cefepime. A multiple antibiotic resistance index (MARI) > 0.2 was found in 30% of the strains, including multidrug-resistant (n = 15) and extensively drug-resistant (n = 3) strains. These findings highlight Pseudomonas spp. as persistent contaminants and antibiotic resistance reservoirs in dairy environments and products, posing public health risks and economic implications for the dairy industry.
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@article {pmid40238238,
year = {2025},
author = {Briega, I and Garde, S and Sánchez, C and Rodríguez-Mínguez, E and Picon, A and Ávila, M},
title = {Evaluation of Biofilm Production and Antibiotic Resistance/Susceptibility Profiles of Pseudomonas spp. Isolated from Milk and Dairy Products.},
journal = {Foods (Basel, Switzerland)},
volume = {14},
number = {7},
pages = {},
doi = {10.3390/foods14071105},
pmid = {40238238},
issn = {2304-8158},
support = {PID2021-122145OR-C21//Ministerio de Ciencia, Innovación y Universidades/ ; JAEINT_22_02476 (Iván Briega)//Consejo Superior de Investigaciones Científicas/ ; },
abstract = {Dairy-borne Pseudomonas spp., known for causing spoilage, may also exhibit antibiotic resistance and form biofilms, enhancing their persistence in dairy environments and contaminating final products. This study examined biofilm formation and antibiotic resistance in 106 Pseudomonas spp. strains isolated from milk, whey, and spoiled dairy products. Phylogenetic analysis (based on partial ileS sequences) grouped most strains within the P. fluorescens group, clustering into the P. fluorescens, P. gessardii, P. koorensis, and P. fragi subgroups. Biofilm formation in polystyrene microplates was assessed at 6 °C and 25 °C by crystal violet staining. After 48 h, 72% and 65% of Pseudomonas strains formed biofilms at 6 °C and 25 °C, respectively, with higher biomass production at 6 °C. High biofilm producers included most P. fluorescens, P. shahriarae, P. salmasensis, P. atacamensis, P. gessardii, P. koreensis, and P. lundensis strains. The adnA gene, associated with biofilm formation, was detected in 60% of the biofilm producers, but was absent in P. fragi, P. lundensis, P. weihenstephanensis, and P. putida. Antibiotic susceptibility was tested using the disk diffusion method. All strains were susceptible to amikacin and tobramycin; however, 73% of the strains were resistant to aztreonam, 28% to imipenem and doripenem, 19% to ceftazidime, 13% to meropenem, and 7% to cefepime. A multiple antibiotic resistance index (MARI) > 0.2 was found in 30% of the strains, including multidrug-resistant (n = 15) and extensively drug-resistant (n = 3) strains. These findings highlight Pseudomonas spp. as persistent contaminants and antibiotic resistance reservoirs in dairy environments and products, posing public health risks and economic implications for the dairy industry.},
}
RevDate: 2025-04-16
Interplay of mycobacterium abscessus and Pseudomonas aeruginosa in experimental models of coinfection: Biofilm dynamics and Host immune response.
Virulence [Epub ahead of print].
The incidence of infection by nontuberculous mycobacteria, mainly Mycobacterium abscessus, is increasing in patients with cystic fibrosis and other chronic pulmonary diseases, leading to an accelerated lung function decline. In most cases, M. abscessus coinfects Pseudomonas aeruginosa, the most common pathogen in these conditions. However, how these two bacterial species interact during infection remains poorly understood. This study explored their behaviour in three relevant pathogenic settings: dual-species biofilm development using a recently developed method to monitor individual species in dual-species biofilms, coinfection in bronchial epithelial cells, and in vivo coinfection in the Galleria mellonella model. The results demonstrated that both species form stable mixed biofilms and reciprocally inhibit single-biofilm progression. Coinfections in bronchial epithelial cells significantly decreased cell viability, whereas in G. mellonella, coinfections induced lower survival rates than individual infections. Analysis of the immune response triggered by each bacterium in bronchial epithelial cell assays and G. mellonella larvae revealed that P. aeruginosa induces the overexpression of proinflammatory and melanization cascade responses, respectively. In contrast, M. abscessus and P. aeruginosa coinfection significantly inhibited the immune response in both models, resulting in worse consequences for the host than those generated by a single P. aeruginosa infection. Overall, this study highlights the novel role of M. abscessus in suppressing immune responses during coinfection with P. aeruginosa, emphasizing the clinical implications for the management of cystic fibrosis and other pulmonary diseases. Understanding these interactions could inform the development of new therapeutic strategies to mitigate the severity of coinfections in vulnerable patients.
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@article {pmid40237819,
year = {2025},
author = {Campo-Pérez, V and Julián, E and Torrents, E},
title = {Interplay of mycobacterium abscessus and Pseudomonas aeruginosa in experimental models of coinfection: Biofilm dynamics and Host immune response.},
journal = {Virulence},
volume = {},
number = {},
pages = {2493221},
doi = {10.1080/21505594.2025.2493221},
pmid = {40237819},
issn = {2150-5608},
abstract = {The incidence of infection by nontuberculous mycobacteria, mainly Mycobacterium abscessus, is increasing in patients with cystic fibrosis and other chronic pulmonary diseases, leading to an accelerated lung function decline. In most cases, M. abscessus coinfects Pseudomonas aeruginosa, the most common pathogen in these conditions. However, how these two bacterial species interact during infection remains poorly understood. This study explored their behaviour in three relevant pathogenic settings: dual-species biofilm development using a recently developed method to monitor individual species in dual-species biofilms, coinfection in bronchial epithelial cells, and in vivo coinfection in the Galleria mellonella model. The results demonstrated that both species form stable mixed biofilms and reciprocally inhibit single-biofilm progression. Coinfections in bronchial epithelial cells significantly decreased cell viability, whereas in G. mellonella, coinfections induced lower survival rates than individual infections. Analysis of the immune response triggered by each bacterium in bronchial epithelial cell assays and G. mellonella larvae revealed that P. aeruginosa induces the overexpression of proinflammatory and melanization cascade responses, respectively. In contrast, M. abscessus and P. aeruginosa coinfection significantly inhibited the immune response in both models, resulting in worse consequences for the host than those generated by a single P. aeruginosa infection. Overall, this study highlights the novel role of M. abscessus in suppressing immune responses during coinfection with P. aeruginosa, emphasizing the clinical implications for the management of cystic fibrosis and other pulmonary diseases. Understanding these interactions could inform the development of new therapeutic strategies to mitigate the severity of coinfections in vulnerable patients.},
}
RevDate: 2025-04-17
Dataset: Compositional analysis and hydrothermal liquefaction of a high-ash microalgae biofilm.
Data in brief, 60:111490.
This dataset contains biochemical composition data and hydrothermal liquefaction (HTL) yield results for a high-ash microalgae biofilm which was cultivated in effluent from a mesophilic anaerobic digester using polyethylene rotating algae biofilm reactors (RABRs). These data were originally collected for use in a techno-economic analysis of biocrude, biodiesel, and bioplastic production from algae that was cultivated using RABRs for municipal wastewater reclamation. Biochemical data for the microalgae biomass includes bulk protein, measured both using the Bradford protein assay and by multiplying total N; carbohydrate content, measured using a 3-methyl-2-benzothiazolinone hydrazone / dithiothreitol (MBTH/DTT) assay; total lipid content, measured using a sulpho-phospho-vanillin method; hexane-extractable lipid content, measured by mass difference after extraction with methanol and hexane; ash content, measured by mass difference after incineration at 550°C; moisture content of the harvested biofilm slurry, measured by mass difference after drying at 60°C, mineral composition, measured using an inductively-coupled plasma spectrophotometer; higher heating value, measured using a bomb calorimeter; and CHNS-O elemental composition, measured using an elemental analyser. Data reported for the HTL product phases include mass yields for each phase (solid, aqueous, biocrude, gas); higher heating value of the biocrude phase, measured using a bomb calorimeter; elemental composition of the biocrude phase, measured using an elemental analyzer; and chemical properties of the aqueous phase, including pH, chemical oxygen demand (HACH method 8000), total nitrogen (HACH method 10,208), total ammonia (HACH method 10,301), total phosphorus (HACH method 10,209/10,210), and total organic carbon (HACH method 10,267). Currently, the effects of ash composition and HTL heating rate on biocrude yields and on N and P partitioning into biocrude, aqueous, and solid phases are not clearly defined. Models used to predict biocrude yields after HTL of microalgae are commonly trained using data collected from numerous studies. This dataset contains the feedstock composition data and ramp rate data necessary to help define the effects of ash content on biocrude yields after HTL and can be reused to help train yield-prediction models for the HTL of microalgae and other feedstocks.
Additional Links: PMID-40235697
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@article {pmid40235697,
year = {2025},
author = {Watkins, JD and Abdellaoui, H and Barton, E and Lords, C and Sims, RC},
title = {Dataset: Compositional analysis and hydrothermal liquefaction of a high-ash microalgae biofilm.},
journal = {Data in brief},
volume = {60},
number = {},
pages = {111490},
pmid = {40235697},
issn = {2352-3409},
abstract = {This dataset contains biochemical composition data and hydrothermal liquefaction (HTL) yield results for a high-ash microalgae biofilm which was cultivated in effluent from a mesophilic anaerobic digester using polyethylene rotating algae biofilm reactors (RABRs). These data were originally collected for use in a techno-economic analysis of biocrude, biodiesel, and bioplastic production from algae that was cultivated using RABRs for municipal wastewater reclamation. Biochemical data for the microalgae biomass includes bulk protein, measured both using the Bradford protein assay and by multiplying total N; carbohydrate content, measured using a 3-methyl-2-benzothiazolinone hydrazone / dithiothreitol (MBTH/DTT) assay; total lipid content, measured using a sulpho-phospho-vanillin method; hexane-extractable lipid content, measured by mass difference after extraction with methanol and hexane; ash content, measured by mass difference after incineration at 550°C; moisture content of the harvested biofilm slurry, measured by mass difference after drying at 60°C, mineral composition, measured using an inductively-coupled plasma spectrophotometer; higher heating value, measured using a bomb calorimeter; and CHNS-O elemental composition, measured using an elemental analyser. Data reported for the HTL product phases include mass yields for each phase (solid, aqueous, biocrude, gas); higher heating value of the biocrude phase, measured using a bomb calorimeter; elemental composition of the biocrude phase, measured using an elemental analyzer; and chemical properties of the aqueous phase, including pH, chemical oxygen demand (HACH method 8000), total nitrogen (HACH method 10,208), total ammonia (HACH method 10,301), total phosphorus (HACH method 10,209/10,210), and total organic carbon (HACH method 10,267). Currently, the effects of ash composition and HTL heating rate on biocrude yields and on N and P partitioning into biocrude, aqueous, and solid phases are not clearly defined. Models used to predict biocrude yields after HTL of microalgae are commonly trained using data collected from numerous studies. This dataset contains the feedstock composition data and ramp rate data necessary to help define the effects of ash content on biocrude yields after HTL and can be reused to help train yield-prediction models for the HTL of microalgae and other feedstocks.},
}
RevDate: 2025-04-17
CmpDate: 2025-04-16
Biofilm formation, methicillin resistance and SCCmec types among Staphylococcus aureus isolated from clinical samples from a tertiary care hospital, in Nepal.
BMC infectious diseases, 25(1):534.
BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) is a human pathogen that can cause hospital and community acquired infections. Biofilm formation is a major virulence factor contributing to its pathogenicity. This study aimed to detect biofilm formation ability among methicillin resistant Staphylococcus aureus (MRSA) clinical isolates and determine SCCmec types.
METHODS: A total of 115 S. aureus were isolated from various clinical samples collected at Nepal Armed Police Hospital from August 2022 to February 2023. The antibiotic susceptibility test was performed via a modified Kirby Bauer disc diffusion method following CLSI guidelines. Phenotypic detection of biofilm formation was performed by microtiter plate assay. Polymerase chain reaction was performed to detect mecA, icaA and SCCmec types.
RESULTS: More than 90% of the isolates were resistant to cefixime and penicillin. Among the total isolates, 66% were multidrug resistant. The disc diffusion method detected 60% of the isolates as MRSA, with 15 isolates lacking the mecA gene. Different levels of biofilm biomass were observed among 86 (75%) of the isolates by microtiter plate method. PCR revealed the presence of the icaA gene in a low number of the isolates (16%). Compared with biofilm nonproducer isolates, biofilm producing S. aureus isolates presented a greater incidence of antibiotic resistance with multi drug resistance (MDR). SCCmec type V (21%) predominated, followed by type II (13%) and most of them were MDR and biofilm producers.
CONCLUSIONS: Our results indicate a relatively high incidence of community acquired S. aureus circulating in the hospital setting. This study is the first to explore the associations between SCCmec types and biofilm formation among clinical isolates in Nepal. Monitoring the prevalence of biofilm producing S. aureus provides valuable insights into the evolving epidemiology of healthcare associated infections, facilitating the development of targeted infection control strategies.
Additional Links: PMID-40234825
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@article {pmid40234825,
year = {2025},
author = {Manandhar, S and Karn, D and Shrestha, MR and Shakya, J and Singh, A},
title = {Biofilm formation, methicillin resistance and SCCmec types among Staphylococcus aureus isolated from clinical samples from a tertiary care hospital, in Nepal.},
journal = {BMC infectious diseases},
volume = {25},
number = {1},
pages = {534},
pmid = {40234825},
issn = {1471-2334},
support = {Faculty research Grant 076/077//University Grants Commission- Nepal/ ; },
mesh = {*Biofilms/growth & development ; Nepal/epidemiology ; Humans ; *Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation & purification/physiology ; Tertiary Care Centers ; *Staphylococcal Infections/microbiology/epidemiology ; Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; Drug Resistance, Multiple, Bacterial ; *Methicillin Resistance ; Penicillin-Binding Proteins/genetics ; Bacterial Proteins/genetics ; },
abstract = {BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) is a human pathogen that can cause hospital and community acquired infections. Biofilm formation is a major virulence factor contributing to its pathogenicity. This study aimed to detect biofilm formation ability among methicillin resistant Staphylococcus aureus (MRSA) clinical isolates and determine SCCmec types.
METHODS: A total of 115 S. aureus were isolated from various clinical samples collected at Nepal Armed Police Hospital from August 2022 to February 2023. The antibiotic susceptibility test was performed via a modified Kirby Bauer disc diffusion method following CLSI guidelines. Phenotypic detection of biofilm formation was performed by microtiter plate assay. Polymerase chain reaction was performed to detect mecA, icaA and SCCmec types.
RESULTS: More than 90% of the isolates were resistant to cefixime and penicillin. Among the total isolates, 66% were multidrug resistant. The disc diffusion method detected 60% of the isolates as MRSA, with 15 isolates lacking the mecA gene. Different levels of biofilm biomass were observed among 86 (75%) of the isolates by microtiter plate method. PCR revealed the presence of the icaA gene in a low number of the isolates (16%). Compared with biofilm nonproducer isolates, biofilm producing S. aureus isolates presented a greater incidence of antibiotic resistance with multi drug resistance (MDR). SCCmec type V (21%) predominated, followed by type II (13%) and most of them were MDR and biofilm producers.
CONCLUSIONS: Our results indicate a relatively high incidence of community acquired S. aureus circulating in the hospital setting. This study is the first to explore the associations between SCCmec types and biofilm formation among clinical isolates in Nepal. Monitoring the prevalence of biofilm producing S. aureus provides valuable insights into the evolving epidemiology of healthcare associated infections, facilitating the development of targeted infection control strategies.},
}
MeSH Terms:
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*Biofilms/growth & development
Nepal/epidemiology
Humans
*Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation & purification/physiology
Tertiary Care Centers
*Staphylococcal Infections/microbiology/epidemiology
Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests
Drug Resistance, Multiple, Bacterial
*Methicillin Resistance
Penicillin-Binding Proteins/genetics
Bacterial Proteins/genetics
RevDate: 2025-04-17
CmpDate: 2025-04-15
Bacterial biofilm-derived H-NS protein acts as a defense against Neutrophil Extracellular Traps (NETs).
NPJ biofilms and microbiomes, 11(1):58.
Extracellular DNA (eDNA) is crucial for the structural integrity of bacterial biofilms as they undergo transformation from B-DNA to Z-DNA as the biofilm matures. This transition to Z-DNA increases biofilm rigidity and prevents binding by canonical B-DNA-binding proteins, including nucleases. One of the primary defenses against bacterial infections are Neutrophil Extracellular Traps (NETs), wherein neutrophils release their own eDNA to trap and kill bacteria. Here we show that H-NS, a bacterial nucleoid associated protein (NAP) that is also released during biofilm development, is able to incapacitate NETs. Indeed, when exposed to human derived neutrophils, H-NS prevented the formation of NETs and lead to NET eDNA retraction in previously formed NETs. NETs that were exposed to H-NS also lost their ability to kill free-living bacteria which made H-NS an attractive therapeutic candidate for the control of NET-related human diseases. A model of H-NS release from biofilms and NET incapacitation is discussed.
Additional Links: PMID-40234459
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@article {pmid40234459,
year = {2025},
author = {Hendricks, AL and More, KR and Devaraj, A and Buzzo, JR and Robledo-Avila, FH and Partida-Sanchez, S and Bakaletz, LO and Goodman, SD},
title = {Bacterial biofilm-derived H-NS protein acts as a defense against Neutrophil Extracellular Traps (NETs).},
journal = {NPJ biofilms and microbiomes},
volume = {11},
number = {1},
pages = {58},
pmid = {40234459},
issn = {2055-5008},
support = {R01DC011818//NIH/NIDCD/ ; R01DC011818//NIH/NIDCD/ ; R01AI155501//NIH/NIAID/ ; },
mesh = {*Extracellular Traps/immunology/metabolism ; *Biofilms/growth & development ; Humans ; *Neutrophils/immunology/microbiology ; *Bacterial Proteins/metabolism/immunology ; *DNA-Binding Proteins/metabolism ; },
abstract = {Extracellular DNA (eDNA) is crucial for the structural integrity of bacterial biofilms as they undergo transformation from B-DNA to Z-DNA as the biofilm matures. This transition to Z-DNA increases biofilm rigidity and prevents binding by canonical B-DNA-binding proteins, including nucleases. One of the primary defenses against bacterial infections are Neutrophil Extracellular Traps (NETs), wherein neutrophils release their own eDNA to trap and kill bacteria. Here we show that H-NS, a bacterial nucleoid associated protein (NAP) that is also released during biofilm development, is able to incapacitate NETs. Indeed, when exposed to human derived neutrophils, H-NS prevented the formation of NETs and lead to NET eDNA retraction in previously formed NETs. NETs that were exposed to H-NS also lost their ability to kill free-living bacteria which made H-NS an attractive therapeutic candidate for the control of NET-related human diseases. A model of H-NS release from biofilms and NET incapacitation is discussed.},
}
MeSH Terms:
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*Extracellular Traps/immunology/metabolism
*Biofilms/growth & development
Humans
*Neutrophils/immunology/microbiology
*Bacterial Proteins/metabolism/immunology
*DNA-Binding Proteins/metabolism
RevDate: 2025-04-15
The effect of commercial sanitizers on Listeria monocytogenes (planktonic and biofilm forms) experimentally inoculated materials commonly used during tree-fruit harvesting.
Letters in applied microbiology pii:8113970 [Epub ahead of print].
This study compares the efficacy of commercially available sanitizers in reducing L. monocytogenes planktonic and biofilm form on surfaces commonly used during tree fruit harvesting. Planktonic L. monocytogenes cells were grown to create a bacterial lawn and inoculated on high density polyethylene plastic, wood, or nylon. Biofilms were grown for 96 h in a Centers for Disease Control reactor on the same surfaces. Bacteria were exposed to free chlorine, peroxyacetic acid, silver-dihydrogen citrate, steam and chlorine dioxide. In planktonic forms, peroxyacetic acid and silver-dihydrogen citrate, applied for 2 min resulted in ≥ 3-log reduction regardless surface type (P < 0.05). Steam and chlorine dioxide efficacy differed significantly by surface type. When applied to Listeria biofilms, steam, chlorine, peroxyacetic acid and chlorine dioxide resulted in an overall significant difference compared to untreated coupons for all surfaces (P < 0.05). Silver-dihydrogen citrate significantly affected population on plastic (P < 0.05), but not on wood or nylon. For porous surfaces few treatments, such as peroxyacetic acid (for nylon) and chlorine dioxide (for wood), resulted in a ≥ 3 log reduction of both forms. Interactions between sanitizer, surfaces and exposure time should be considered by tree fruit harvesting facilities when determining sanitation strategies to be implemented.
Additional Links: PMID-40234214
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@article {pmid40234214,
year = {2025},
author = {Stewart, S and Chalamalasetti, S and Ruiz-Llacsahuanga, B and Critzer, F and Bhullar, M and Nwadike, L and Yucel, U and Trinetta, V},
title = {The effect of commercial sanitizers on Listeria monocytogenes (planktonic and biofilm forms) experimentally inoculated materials commonly used during tree-fruit harvesting.},
journal = {Letters in applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/lambio/ovaf056},
pmid = {40234214},
issn = {1472-765X},
abstract = {This study compares the efficacy of commercially available sanitizers in reducing L. monocytogenes planktonic and biofilm form on surfaces commonly used during tree fruit harvesting. Planktonic L. monocytogenes cells were grown to create a bacterial lawn and inoculated on high density polyethylene plastic, wood, or nylon. Biofilms were grown for 96 h in a Centers for Disease Control reactor on the same surfaces. Bacteria were exposed to free chlorine, peroxyacetic acid, silver-dihydrogen citrate, steam and chlorine dioxide. In planktonic forms, peroxyacetic acid and silver-dihydrogen citrate, applied for 2 min resulted in ≥ 3-log reduction regardless surface type (P < 0.05). Steam and chlorine dioxide efficacy differed significantly by surface type. When applied to Listeria biofilms, steam, chlorine, peroxyacetic acid and chlorine dioxide resulted in an overall significant difference compared to untreated coupons for all surfaces (P < 0.05). Silver-dihydrogen citrate significantly affected population on plastic (P < 0.05), but not on wood or nylon. For porous surfaces few treatments, such as peroxyacetic acid (for nylon) and chlorine dioxide (for wood), resulted in a ≥ 3 log reduction of both forms. Interactions between sanitizer, surfaces and exposure time should be considered by tree fruit harvesting facilities when determining sanitation strategies to be implemented.},
}
RevDate: 2025-04-15
Degradation of organic pollutant by natural biofilm based biophotovoltaic cells: The combined role of illumination, reactive oxygen species, and enhanced electron transfer.
Bioresource technology pii:S0960-8524(25)00503-6 [Epub ahead of print].
Autotrophic biofilms in natural water can produce reactive oxygen species (ROS) and degrade organic pollutants. To test the feasibility of applying natural biofilms in biophotovoltaic (BPV) cells, a simple single-chamber BPV using biofilms developed in lake water as the microbial anode was constructed, and electricity production and pollutant removal capacity of the BPV were evaluated. The natural biofilm BPV (NB-BPV) established was a robust and self-sustaining BPV with positive light response in electricity generation and sustainable power generation in the dark. Under visible light illumination, the voltage of the NB-BPV reached a maximum output of 150.6 ± 0.7 mV, with a power density of 326.4 μW/m[2] (per electrode surface area). Meanwhile, it could effectively degrade sodium dodecylbenzene sulfonate (DBS), while generating electricity, and the removal rate of DBS and TOC in 36 h was 77.1 % and 53.2 %, respectively. Under sunlight, NB-BPV could also produce electricity steadily in lake and the removal rate of DBS in simulated lake water was 93.7 % (120 h). Visible light significantly affected the performance of NB-BPV mainly through photosynthesis. Photosynthesis of biofilm promoted electricity generation and significantly enhanced the degradation of DBS by promoting electron transfer activity and generating ROS. Compared with biofilm system, the closed-circuit in NB-BPV promoted electron transfer, allowing more efficient degradation of DBS at relatively low level of ROS. Such a novel self-sustainable BPV has the potential to degrade refractory pollutants, and to be used in natural water.
Additional Links: PMID-40233881
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@article {pmid40233881,
year = {2025},
author = {Qi, Z and Hua, X and Li, A and Liu, H and Dong, D and Liang, D and Guo, Z and Zheng, N},
title = {Degradation of organic pollutant by natural biofilm based biophotovoltaic cells: The combined role of illumination, reactive oxygen species, and enhanced electron transfer.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {132537},
doi = {10.1016/j.biortech.2025.132537},
pmid = {40233881},
issn = {1873-2976},
abstract = {Autotrophic biofilms in natural water can produce reactive oxygen species (ROS) and degrade organic pollutants. To test the feasibility of applying natural biofilms in biophotovoltaic (BPV) cells, a simple single-chamber BPV using biofilms developed in lake water as the microbial anode was constructed, and electricity production and pollutant removal capacity of the BPV were evaluated. The natural biofilm BPV (NB-BPV) established was a robust and self-sustaining BPV with positive light response in electricity generation and sustainable power generation in the dark. Under visible light illumination, the voltage of the NB-BPV reached a maximum output of 150.6 ± 0.7 mV, with a power density of 326.4 μW/m[2] (per electrode surface area). Meanwhile, it could effectively degrade sodium dodecylbenzene sulfonate (DBS), while generating electricity, and the removal rate of DBS and TOC in 36 h was 77.1 % and 53.2 %, respectively. Under sunlight, NB-BPV could also produce electricity steadily in lake and the removal rate of DBS in simulated lake water was 93.7 % (120 h). Visible light significantly affected the performance of NB-BPV mainly through photosynthesis. Photosynthesis of biofilm promoted electricity generation and significantly enhanced the degradation of DBS by promoting electron transfer activity and generating ROS. Compared with biofilm system, the closed-circuit in NB-BPV promoted electron transfer, allowing more efficient degradation of DBS at relatively low level of ROS. Such a novel self-sustainable BPV has the potential to degrade refractory pollutants, and to be used in natural water.},
}
RevDate: 2025-04-15
Brazilian Organic Honeydew Reduces In Vitro and In Vivo Periodontal Disease-Related Subgingival Biofilm.
Foods (Basel, Switzerland), 14(6):.
We investigated the antimicrobial properties and effects on bone resorption of Brazilian organic honeydew (OHD) from the Bracatinga tree (Mimosa scabrella Benth.), a rare honey certified with Denomination of Origin, using a periodontal disease model. Antibiofilm activity was assessed using a subgingival biofilm adhered to the Calgary device. Biofilms were treated with OHD, chlorhexidine (0.12%), or a vehicle twice daily for 1 min starting on day 3, at concentrations of 2× and 10× the minimum inhibitory concentration (MIC). We employed a ligature-induced chronic periodontal disease model and challenged it with Porphyromonas gingivalis in C57BL/6 mice. The chemical profile of OHD was analyzed using LC-ESI-IT-MS/MS. Results were evaluated by measuring bone loss and microbial composition of the ligature biofilm through DNA-DNA hybridization. OHD demonstrated significant activity against P. gingivalis (MIC 4%, MBC 6%) and reduced biofilm viability by 80% in vitro. In vivo, OHD decreased microbial populations and decreased bone loss associated with periodontal disease. Chemical analysis identified seven compounds in OHD, including five flavonoids and two lignans. This Brazilian honeydew from the Atlantic Forest exhibits strong antimicrobial properties and potential as a functional food for oral health, offering a promising alternative for the control and prevention of periodontal disease.
Additional Links: PMID-40232035
PubMed:
Citation:
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@article {pmid40232035,
year = {2025},
author = {Romário-Silva, D and Franchin, M and Bueno-Silva, B and Saliba, ASMC and Sardi, JO and Alves-Ferreira, T and Lazarini, JG and Cunha, GA and de Alencar, SM and Rosalen, PL},
title = {Brazilian Organic Honeydew Reduces In Vitro and In Vivo Periodontal Disease-Related Subgingival Biofilm.},
journal = {Foods (Basel, Switzerland)},
volume = {14},
number = {6},
pages = {},
pmid = {40232035},
issn = {2304-8158},
support = {88887476194/2020-00//Coordenação de Aperfeiçoamento de Pessoal de Nível 595 Superior/ ; 141129/2017-4//Conselho Nacional de Desenvolvimento 596 Científico e Tecnológico/ ; },
abstract = {We investigated the antimicrobial properties and effects on bone resorption of Brazilian organic honeydew (OHD) from the Bracatinga tree (Mimosa scabrella Benth.), a rare honey certified with Denomination of Origin, using a periodontal disease model. Antibiofilm activity was assessed using a subgingival biofilm adhered to the Calgary device. Biofilms were treated with OHD, chlorhexidine (0.12%), or a vehicle twice daily for 1 min starting on day 3, at concentrations of 2× and 10× the minimum inhibitory concentration (MIC). We employed a ligature-induced chronic periodontal disease model and challenged it with Porphyromonas gingivalis in C57BL/6 mice. The chemical profile of OHD was analyzed using LC-ESI-IT-MS/MS. Results were evaluated by measuring bone loss and microbial composition of the ligature biofilm through DNA-DNA hybridization. OHD demonstrated significant activity against P. gingivalis (MIC 4%, MBC 6%) and reduced biofilm viability by 80% in vitro. In vivo, OHD decreased microbial populations and decreased bone loss associated with periodontal disease. Chemical analysis identified seven compounds in OHD, including five flavonoids and two lignans. This Brazilian honeydew from the Atlantic Forest exhibits strong antimicrobial properties and potential as a functional food for oral health, offering a promising alternative for the control and prevention of periodontal disease.},
}
RevDate: 2025-04-16
Nanowire arrays with programmable geometries as a highly effective anti-biofilm surface.
Biofilm, 9:100275.
Biofilm-related microbial infections are the Achilles' heel of many implantable medical devices. Surface patterning with nanostructures in the form of vertically aligned silicon (Si) nanowires (VA-SiNWs) holds promise to prevent these often "incurable" infections. In this study, we fabricated arrays of highly ordered SiNWs varying in three geometric parameters, including height, pitch size, and tip diameter (sharpness). Anti-infective efficacies of fabricated SiNW arrays were assessed against representative laboratory reference bacterial strains, Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922, using a modified microwell biofilm assay representing microorganism-implant interactions at a liquid-solid interface. To further understand the role of individual geometric parameters to the SiNW-induced bacterial killing, SiNW arrays with stepwise changes in individual geometric parameters were compared. The force that NWs applied on bacterial cells was mathematically calculated. Our results suggested that NWs with specific geometries were able to kill adherent bacterial cells and prevent further biofilm formation on biomaterial surfaces. Tip diameter and pitch size appeared to be key factors of nanowires predetermining their anti-infectiveness. Mechanistic investigation found that tip diameter and pitch size co-determined the pressure that NWs put on the cell envelope. The most effective anti-infective NWs fabricated in our study (50 nm in tip diameter and 400 nm in pitch size for S. aureus and 50 nm in tip diameter and 800 nm in pitch size for E. coli) put pressures of approximately 2.79 Pa and 8.86 Pa to the cell envelop of S. aureus and E. coli, respectively, and induced cell lyses. In addition, these NWs retained their activities against clinical isolates of S. aureus and E. coli from patients with confirmed device-related infections and showed little toxicity against human fibroblast cells and red blood cells.
Additional Links: PMID-40230726
PubMed:
Citation:
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@article {pmid40230726,
year = {2025},
author = {George, MA and McGiffin, D and Peleg, AY and Elnathan, R and Kaye, DM and Qu, Y and Voelcker, NH},
title = {Nanowire arrays with programmable geometries as a highly effective anti-biofilm surface.},
journal = {Biofilm},
volume = {9},
number = {},
pages = {100275},
pmid = {40230726},
issn = {2590-2075},
abstract = {Biofilm-related microbial infections are the Achilles' heel of many implantable medical devices. Surface patterning with nanostructures in the form of vertically aligned silicon (Si) nanowires (VA-SiNWs) holds promise to prevent these often "incurable" infections. In this study, we fabricated arrays of highly ordered SiNWs varying in three geometric parameters, including height, pitch size, and tip diameter (sharpness). Anti-infective efficacies of fabricated SiNW arrays were assessed against representative laboratory reference bacterial strains, Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922, using a modified microwell biofilm assay representing microorganism-implant interactions at a liquid-solid interface. To further understand the role of individual geometric parameters to the SiNW-induced bacterial killing, SiNW arrays with stepwise changes in individual geometric parameters were compared. The force that NWs applied on bacterial cells was mathematically calculated. Our results suggested that NWs with specific geometries were able to kill adherent bacterial cells and prevent further biofilm formation on biomaterial surfaces. Tip diameter and pitch size appeared to be key factors of nanowires predetermining their anti-infectiveness. Mechanistic investigation found that tip diameter and pitch size co-determined the pressure that NWs put on the cell envelope. The most effective anti-infective NWs fabricated in our study (50 nm in tip diameter and 400 nm in pitch size for S. aureus and 50 nm in tip diameter and 800 nm in pitch size for E. coli) put pressures of approximately 2.79 Pa and 8.86 Pa to the cell envelop of S. aureus and E. coli, respectively, and induced cell lyses. In addition, these NWs retained their activities against clinical isolates of S. aureus and E. coli from patients with confirmed device-related infections and showed little toxicity against human fibroblast cells and red blood cells.},
}
RevDate: 2025-04-14
Disruption of MRSA Biofilm and Virulence by Deep-Sea Probiotics: Impacts on Energy metabolism and Host Antimicrobial Peptides.
Probiotics and antimicrobial proteins [Epub ahead of print].
Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant threat to public health due to its resistance to conventional antibiotics and its ability to form robust biofilms on both biotic and abiotic surfaces. In this study, we explore the novel mechanisms by which deep-sea-derived probiotics serve as an alternative strategy to combat MRSA infections. Three promising probiotic candidates, Lactococcus lactis (L25_4) and two strains of Leuconostoc pseudomesenteroides (L25_6 and L25_7), were isolated from ocean water collected at a depth of 312 m off the eastern coast of Taiwan. Each candidate strain demonstrated potent antimicrobial activity, significantly reducing MRSA biofilm formation when applied to pork skin. The strains also improved survival rates in a Galleria mellonella infection model (> 90% survival). Immunomodulatory effects were evident, with marked upregulation of Cecropin antimicrobial peptide (AMP) and downregulation of Gloverin AMP in the host. Scanning and transmission electron microscopy (SEM and TEM) revealed that probiotic treatments compromised MRSA cell membrane integrity, consistent with transcriptomic analysis showing downregulation of genes related to protein translation, membrane structure, and transporter systems. Collectively, our comprehensive in vitro, in vivo, ex vivo, and transcriptomic analyses reveal the intricate mechanisms by which deep-sea probiotics modulate both host and MRSA gene expression, underscoring their potential as innovative tools for addressing antibiotic-resistant infections.
Additional Links: PMID-40229459
PubMed:
Citation:
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@article {pmid40229459,
year = {2025},
author = {Negi, A and Kuo, CW and Hazam, PK and Yeh, JC and Lin, WC and Lou, YC and Yu, CY and Yu, TL and Lu, TM and Chen, JY},
title = {Disruption of MRSA Biofilm and Virulence by Deep-Sea Probiotics: Impacts on Energy metabolism and Host Antimicrobial Peptides.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {40229459},
issn = {1867-1314},
support = {109-2313-B-001-007-MY3, 111-2622-B-001-001//National Science and Technology Council/ ; },
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant threat to public health due to its resistance to conventional antibiotics and its ability to form robust biofilms on both biotic and abiotic surfaces. In this study, we explore the novel mechanisms by which deep-sea-derived probiotics serve as an alternative strategy to combat MRSA infections. Three promising probiotic candidates, Lactococcus lactis (L25_4) and two strains of Leuconostoc pseudomesenteroides (L25_6 and L25_7), were isolated from ocean water collected at a depth of 312 m off the eastern coast of Taiwan. Each candidate strain demonstrated potent antimicrobial activity, significantly reducing MRSA biofilm formation when applied to pork skin. The strains also improved survival rates in a Galleria mellonella infection model (> 90% survival). Immunomodulatory effects were evident, with marked upregulation of Cecropin antimicrobial peptide (AMP) and downregulation of Gloverin AMP in the host. Scanning and transmission electron microscopy (SEM and TEM) revealed that probiotic treatments compromised MRSA cell membrane integrity, consistent with transcriptomic analysis showing downregulation of genes related to protein translation, membrane structure, and transporter systems. Collectively, our comprehensive in vitro, in vivo, ex vivo, and transcriptomic analyses reveal the intricate mechanisms by which deep-sea probiotics modulate both host and MRSA gene expression, underscoring their potential as innovative tools for addressing antibiotic-resistant infections.},
}
RevDate: 2025-04-14
Chitosan-aloe vera scaffolds with tuned extracellular vesicles and histatin-5 display osteogenic and anti-biofilm activities.
International journal of pharmaceutics pii:S0378-5173(25)00429-6 [Epub ahead of print].
The use of extracellular vesicles (EVs) has garnered significant attention as an alternative to cell-based therapies due to their stability and biocompatibility. In this study, we stimulated mesenchymal stem cells (MSCs) with therapeutic agents affecting the bone regenerative cascade, including bone morphogenetic protein 2 (BMP-2), stromal-derived factor (SDF-1), interleukin 4 (IL-4), alendronate (ALD) and osteogenic differentiation media to obtain osteogenic EVs. The tuned EVs were tested on MSCs and fibroblasts, selecting EVs-BMP2 as suitable systems. Chitosan-aloe vera (AV) scaffolds were designed to allow for the loading and release of these EVs while leveraging the antibacterial and anti-inflammatory properties of AV. To enhance the dual effect on regeneration and antibacterial activity, poly(lactic-co-glycolic acid) (PLGA) microspheres encapsulating Histatin 5 (Hist-5) were incorporated to the scaffolds. Hist-5 encapsulation was successful, and effectively prevented Staphylococcus aureus biofilm formation on the scaffolds surface. The optimized chitosan-AV scaffolds loaded with EVs-BMP-2 promoted MSCs adhesion and proliferation and exhibited a 2-fold increase in osteogenic differentiation compared to chitosan scaffolds. This study demonstrates the successful combination of bioengineered EVs and Hist-5-loaded microspheres within a chitosan-AV scaffold, providing a promising dual approach for enhancing bone regeneration while reducing the risk of infection. These systems show potential as effective implants for bone fractures, offering both antibacterial and regenerative capabilities.
Additional Links: PMID-40228611
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PubMed:
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@article {pmid40228611,
year = {2025},
author = {García-García, P and Évora, C and Delgado, A and Diaz-Rodriguez, P},
title = {Chitosan-aloe vera scaffolds with tuned extracellular vesicles and histatin-5 display osteogenic and anti-biofilm activities.},
journal = {International journal of pharmaceutics},
volume = {},
number = {},
pages = {125592},
doi = {10.1016/j.ijpharm.2025.125592},
pmid = {40228611},
issn = {1873-3476},
abstract = {The use of extracellular vesicles (EVs) has garnered significant attention as an alternative to cell-based therapies due to their stability and biocompatibility. In this study, we stimulated mesenchymal stem cells (MSCs) with therapeutic agents affecting the bone regenerative cascade, including bone morphogenetic protein 2 (BMP-2), stromal-derived factor (SDF-1), interleukin 4 (IL-4), alendronate (ALD) and osteogenic differentiation media to obtain osteogenic EVs. The tuned EVs were tested on MSCs and fibroblasts, selecting EVs-BMP2 as suitable systems. Chitosan-aloe vera (AV) scaffolds were designed to allow for the loading and release of these EVs while leveraging the antibacterial and anti-inflammatory properties of AV. To enhance the dual effect on regeneration and antibacterial activity, poly(lactic-co-glycolic acid) (PLGA) microspheres encapsulating Histatin 5 (Hist-5) were incorporated to the scaffolds. Hist-5 encapsulation was successful, and effectively prevented Staphylococcus aureus biofilm formation on the scaffolds surface. The optimized chitosan-AV scaffolds loaded with EVs-BMP-2 promoted MSCs adhesion and proliferation and exhibited a 2-fold increase in osteogenic differentiation compared to chitosan scaffolds. This study demonstrates the successful combination of bioengineered EVs and Hist-5-loaded microspheres within a chitosan-AV scaffold, providing a promising dual approach for enhancing bone regeneration while reducing the risk of infection. These systems show potential as effective implants for bone fractures, offering both antibacterial and regenerative capabilities.},
}
RevDate: 2025-04-14
Simulation of head-tail biofilm streamer growth based on immersed boundary method.
Biofouling [Epub ahead of print].
Biofilms are subjected to various forces in the fluid field, as a result, the biofilm forms a head-tail structure known as a streamer to reduce pressure differential resistance. To characterize biofilm growth in fluid, we establish a head-tail biofilm streamer growth model based on the immersed boundary method using MATLAB software, and simulate streamer growth in various environmental conditions to explore the factors affecting its growth. Firstly, we found that a higher flow velocity makes the streamer grow faster and thereby produce more biomass. Secondly, we explored the effect of the position of nutrient source on the streamer growth, found that when the nutrient source overlaps with the streamer, its length is longer than when the nutrient source and the streamer are mismatched. Further we found that the Young's modulus of the streamer also influences its growth length. Streamers with small Young's modulus were more likely to deform, making them grow longer than the streamers with large Young's modulus. Finally, we determined the relationship between the tail length and the head diameter of the streamer through mechanical analysis, and found that there is an optimal ratio of the tail length to the head diameter which exposes the streamer to the minimum drag in the fluid field.
Additional Links: PMID-40226987
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PubMed:
Citation:
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@article {pmid40226987,
year = {2025},
author = {Fu, Y and Wang, J and Wang, X},
title = {Simulation of head-tail biofilm streamer growth based on immersed boundary method.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-13},
doi = {10.1080/08927014.2025.2490748},
pmid = {40226987},
issn = {1029-2454},
abstract = {Biofilms are subjected to various forces in the fluid field, as a result, the biofilm forms a head-tail structure known as a streamer to reduce pressure differential resistance. To characterize biofilm growth in fluid, we establish a head-tail biofilm streamer growth model based on the immersed boundary method using MATLAB software, and simulate streamer growth in various environmental conditions to explore the factors affecting its growth. Firstly, we found that a higher flow velocity makes the streamer grow faster and thereby produce more biomass. Secondly, we explored the effect of the position of nutrient source on the streamer growth, found that when the nutrient source overlaps with the streamer, its length is longer than when the nutrient source and the streamer are mismatched. Further we found that the Young's modulus of the streamer also influences its growth length. Streamers with small Young's modulus were more likely to deform, making them grow longer than the streamers with large Young's modulus. Finally, we determined the relationship between the tail length and the head diameter of the streamer through mechanical analysis, and found that there is an optimal ratio of the tail length to the head diameter which exposes the streamer to the minimum drag in the fluid field.},
}
RevDate: 2025-04-16
CmpDate: 2025-04-13
Novel strategies for vancomycin-resistant Enterococcus faecalis biofilm control: bacteriophage (vB_EfaS_ZC1), propolis, and their combined effects in an ex vivo endodontic model.
Annals of clinical microbiology and antimicrobials, 24(1):24.
BACKGROUND: Endodontic treatment failures are predominantly attributed to Enterococcus faecalis (E. faecalis) infection, a Gram-positive coccus. E. faecalis forms biofilms, resist multiple antibiotics, and can withstand endodontic disinfection protocols. Vancomycin-resistant strains, in particular, are challenging to treat and are associated with serious medical complications.
METHODS: A novel phage, vB_EfaS_ZC1, was isolated and characterized. Its lytic activity against E. faecalis was assessed in vitro through time-killing and biofilm assays. The phage's stability under various conditions was determined. Genomic analysis was conducted to characterize the phage and its virulence. The phage, propolis, and their combination were evaluated as an intracanal irrigation solution against a 4-week E. faecalis mature biofilm, using an ex vivo infected human dentin model. The antibiofilm activity was analyzed using a colony-forming unit assay, field emission scanning electron microscopy, and confocal laser scanning microscopy.
RESULTS: The isolated phage, vB_EfaS_ZC1, a siphovirus with prolate capsid, exhibited strong lytic activity against Vancomycin-resistant strains. In vitro assays indicated its effectiveness in inhibiting planktonic growth and disrupting mature biofilms. The phage remained stable under wide range of temperatures (- 80 to 60 °C), tolerated pH levels from 4 to 11; however the phage viability significantly reduced after UV exposure. Genomic analysis strongly suggests the phage's virulence and suitability for therapeutic applications; neither lysogeny markers nor antibiotic resistance markers were identified. Phylogenetic analysis clustered vB_EfaS_ZC1 within the genus Saphexavirus. The phage, both alone and in combination with propolis, demonstrated potent antibiofilm effects compared to conventional root canal irrigation.
CONCLUSION: Phage vB_EfaS_ZC1 demonstrates a promising therapy, either individually or in combination with propolis, for addressing challenging endodontic infections caused by E. faecalis.
Additional Links: PMID-40223105
PubMed:
Citation:
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@article {pmid40223105,
year = {2025},
author = {Hakim, TA and Zaki, BM and Mohamed, DA and Blasdel, B and Gad, MA and Fayez, MS and El-Shibiny, A},
title = {Novel strategies for vancomycin-resistant Enterococcus faecalis biofilm control: bacteriophage (vB_EfaS_ZC1), propolis, and their combined effects in an ex vivo endodontic model.},
journal = {Annals of clinical microbiology and antimicrobials},
volume = {24},
number = {1},
pages = {24},
pmid = {40223105},
issn = {1476-0711},
support = {Round 8//Academy of Scientific Research and Technology/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Enterococcus faecalis/virology/drug effects/physiology ; Humans ; *Bacteriophages/physiology/genetics/isolation & purification ; *Propolis/pharmacology ; Gram-Positive Bacterial Infections/therapy/microbiology ; Anti-Bacterial Agents/pharmacology ; *Vancomycin-Resistant Enterococci/virology/drug effects/physiology ; Vancomycin Resistance ; Virulence ; Vancomycin/pharmacology ; },
abstract = {BACKGROUND: Endodontic treatment failures are predominantly attributed to Enterococcus faecalis (E. faecalis) infection, a Gram-positive coccus. E. faecalis forms biofilms, resist multiple antibiotics, and can withstand endodontic disinfection protocols. Vancomycin-resistant strains, in particular, are challenging to treat and are associated with serious medical complications.
METHODS: A novel phage, vB_EfaS_ZC1, was isolated and characterized. Its lytic activity against E. faecalis was assessed in vitro through time-killing and biofilm assays. The phage's stability under various conditions was determined. Genomic analysis was conducted to characterize the phage and its virulence. The phage, propolis, and their combination were evaluated as an intracanal irrigation solution against a 4-week E. faecalis mature biofilm, using an ex vivo infected human dentin model. The antibiofilm activity was analyzed using a colony-forming unit assay, field emission scanning electron microscopy, and confocal laser scanning microscopy.
RESULTS: The isolated phage, vB_EfaS_ZC1, a siphovirus with prolate capsid, exhibited strong lytic activity against Vancomycin-resistant strains. In vitro assays indicated its effectiveness in inhibiting planktonic growth and disrupting mature biofilms. The phage remained stable under wide range of temperatures (- 80 to 60 °C), tolerated pH levels from 4 to 11; however the phage viability significantly reduced after UV exposure. Genomic analysis strongly suggests the phage's virulence and suitability for therapeutic applications; neither lysogeny markers nor antibiotic resistance markers were identified. Phylogenetic analysis clustered vB_EfaS_ZC1 within the genus Saphexavirus. The phage, both alone and in combination with propolis, demonstrated potent antibiofilm effects compared to conventional root canal irrigation.
CONCLUSION: Phage vB_EfaS_ZC1 demonstrates a promising therapy, either individually or in combination with propolis, for addressing challenging endodontic infections caused by E. faecalis.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Enterococcus faecalis/virology/drug effects/physiology
Humans
*Bacteriophages/physiology/genetics/isolation & purification
*Propolis/pharmacology
Gram-Positive Bacterial Infections/therapy/microbiology
Anti-Bacterial Agents/pharmacology
*Vancomycin-Resistant Enterococci/virology/drug effects/physiology
Vancomycin Resistance
Virulence
Vancomycin/pharmacology
RevDate: 2025-04-13
The treated wastewater enhances the biodegradation of sulfonamide antibiotics in biofilm-sediment downstream of the receiving river outlet.
Environmental research pii:S0013-9351(25)00851-5 [Epub ahead of print].
Although the treated wastewater meets the discharge standards, it can still become a potential transmitted stressor that affects aquatic organisms in receiving rivers. Biofilms and sediments as the main solid-phase substances in natural aquatic environments can biodegrade micropollutants. However, most of the current studies have selected a single solid-phase material, and there are relatively few studies that comprehensively consider the effect of treated wastewater on the dissipation of micropollutants in a composite biofilm-sediment system. Therefore, this study investigated the dissipation pathways of six sulfonamide antibiotics (SAs) in biofilm-sediment and the effect of treated wastewater on SAs dissipation. The results showed that biodegradation was the main pathway for SAs dissipation in biofilm-sediment. The input of treated wastewater increased the abundance of dominant degradation bacteria Burkholderiales and Pseudomonadale, thereby improving the biodegradation rate of SAs (approximately 1.5 times higher than upstream degradation rate). These genera could also be further integrated into downstream communities to continuously mediate the biodegradation of SAs. Through mass spectrometry and metagenomic sequencing analysis, it was found that the common degradation pathways of SAs in biofilm-sediment affected by treated wastewater are acetylation, formylation, hydroxylation, and bond cleavage. Acetyltransferase played an important role in the biodegradation of SAs. In addition, the enrichment of antibiotic resistant genes during biodegradation increased the risk of their spread in the aquatic environment. These findings provide new insights into the fate of antibiotics in aquatic environments and the impact of treated wastewater on downstream bacterial communities.
Additional Links: PMID-40222473
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PubMed:
Citation:
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@article {pmid40222473,
year = {2025},
author = {Jing, K and Li, Y and Li, Y and Meng, Q and Guan, Q},
title = {The treated wastewater enhances the biodegradation of sulfonamide antibiotics in biofilm-sediment downstream of the receiving river outlet.},
journal = {Environmental research},
volume = {},
number = {},
pages = {121600},
doi = {10.1016/j.envres.2025.121600},
pmid = {40222473},
issn = {1096-0953},
abstract = {Although the treated wastewater meets the discharge standards, it can still become a potential transmitted stressor that affects aquatic organisms in receiving rivers. Biofilms and sediments as the main solid-phase substances in natural aquatic environments can biodegrade micropollutants. However, most of the current studies have selected a single solid-phase material, and there are relatively few studies that comprehensively consider the effect of treated wastewater on the dissipation of micropollutants in a composite biofilm-sediment system. Therefore, this study investigated the dissipation pathways of six sulfonamide antibiotics (SAs) in biofilm-sediment and the effect of treated wastewater on SAs dissipation. The results showed that biodegradation was the main pathway for SAs dissipation in biofilm-sediment. The input of treated wastewater increased the abundance of dominant degradation bacteria Burkholderiales and Pseudomonadale, thereby improving the biodegradation rate of SAs (approximately 1.5 times higher than upstream degradation rate). These genera could also be further integrated into downstream communities to continuously mediate the biodegradation of SAs. Through mass spectrometry and metagenomic sequencing analysis, it was found that the common degradation pathways of SAs in biofilm-sediment affected by treated wastewater are acetylation, formylation, hydroxylation, and bond cleavage. Acetyltransferase played an important role in the biodegradation of SAs. In addition, the enrichment of antibiotic resistant genes during biodegradation increased the risk of their spread in the aquatic environment. These findings provide new insights into the fate of antibiotics in aquatic environments and the impact of treated wastewater on downstream bacterial communities.},
}
RevDate: 2025-04-13
Sublethal sanitizers exposure differentially affects biofilm formation in three adapted Salmonella strains: A phenotypic-transcriptomic analysis of increased biofilm formed by ATCC 14028.
International journal of food microbiology, 436:111189 pii:S0168-1605(25)00134-5 [Epub ahead of print].
PURPOSE: Using sanitizer in food industry is an important mean of sterilization and biofilm eradication, but inappropriate operation may lead to resistance, posing a concealed risk to food safety. The purpose of this study was to assess the impact of sub-lethal sanitizers on the biofilm formed by adaptive Salmonella and to explore the variations in transcription within adaptive Salmonella biofilms when co-incubated with sublethal concentrations of sanitizers.
METHODS: The microbroth dilution method was determined to measure the MIC of three sanitizers on Salmonella, and adaptation induction was conducted with steadily increasing sanitizer concentrations. The effect of sub-MIC sanitizers on the biofilm of Salmonella was investigated by crystal violet method, confocal laser scanning microscopy and transcriptomics.
RESULTS: The results indicated that the maximum growth concentration of the adapted strains was 1.69-43.25 times that of the original MIC, and the number of bacteria and matrix content were increased when re-exposed to sub-MIC benzalkonium chloride (BZK), and the expression of regulatory factors and various amino acid biosynthesis and metabolism-related genes showed an up-regulation trend.
SIGNIFICANCE: This will be beneficial to clarify the correlation and mechanism between the sanitizer adaptation of salmonellae caused by improper sanitization and increased biofilm formation resulting from this adaptation. And it helps to adjust the appropriate dosage of sanitizer and optimize sanitation standard operating procedures (SSOP) in the foodstuff industry, thereby effectively promoting the bactericidal effect and eliminating foodborne pathogens' biofilm.
Additional Links: PMID-40222328
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PubMed:
Citation:
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@article {pmid40222328,
year = {2025},
author = {Yan, X and Tao, R and Zhou, H and Zhang, Y and Chen, D and Ma, L and Bai, Y},
title = {Sublethal sanitizers exposure differentially affects biofilm formation in three adapted Salmonella strains: A phenotypic-transcriptomic analysis of increased biofilm formed by ATCC 14028.},
journal = {International journal of food microbiology},
volume = {436},
number = {},
pages = {111189},
doi = {10.1016/j.ijfoodmicro.2025.111189},
pmid = {40222328},
issn = {1879-3460},
abstract = {PURPOSE: Using sanitizer in food industry is an important mean of sterilization and biofilm eradication, but inappropriate operation may lead to resistance, posing a concealed risk to food safety. The purpose of this study was to assess the impact of sub-lethal sanitizers on the biofilm formed by adaptive Salmonella and to explore the variations in transcription within adaptive Salmonella biofilms when co-incubated with sublethal concentrations of sanitizers.
METHODS: The microbroth dilution method was determined to measure the MIC of three sanitizers on Salmonella, and adaptation induction was conducted with steadily increasing sanitizer concentrations. The effect of sub-MIC sanitizers on the biofilm of Salmonella was investigated by crystal violet method, confocal laser scanning microscopy and transcriptomics.
RESULTS: The results indicated that the maximum growth concentration of the adapted strains was 1.69-43.25 times that of the original MIC, and the number of bacteria and matrix content were increased when re-exposed to sub-MIC benzalkonium chloride (BZK), and the expression of regulatory factors and various amino acid biosynthesis and metabolism-related genes showed an up-regulation trend.
SIGNIFICANCE: This will be beneficial to clarify the correlation and mechanism between the sanitizer adaptation of salmonellae caused by improper sanitization and increased biofilm formation resulting from this adaptation. And it helps to adjust the appropriate dosage of sanitizer and optimize sanitation standard operating procedures (SSOP) in the foodstuff industry, thereby effectively promoting the bactericidal effect and eliminating foodborne pathogens' biofilm.},
}
RevDate: 2025-04-15
CmpDate: 2025-04-12
Disrupting antimicrobial resistance: unveiling the potential of vitamin C in combating biofilm formation in drug-resistant bacteria.
BMC microbiology, 25(1):212.
BACKGROUND: Antimicrobial resistance (AMR) poses a significant threat to global health, exacerbated by the protective mechanisms of biofilms formed by drug-resistant bacteria. Extracellular polymeric substances (EPS) produced by bacteria in biofilms serve as a formidable shield, impeding the efficacy of antimicrobial agents. Here, we investigated the potential of vitamin C (sodium ascorbate) to disrupt biofilm formation in drug-resistant bacteria isolated from diabetic foot ulcer (DFU) patients and studied the antimicrobial and antibiofilm activity of vitamin C on these bacteria.
RESULTS: Out of 117 study isolates, primarily identified as Escherichia coli (n = 52), Staphylococcus spp. (n = 19), and Klebsiella spp. (n = 46), 80 isolates exhibited a Multiple Antimicrobial Resistance (MAR) index greater than 0.2, classifying them as multi-drug resistant (MDR) superbugs. Among these, 58 isolates demonstrated moderate to strong biofilm-forming abilities and were selected for further experiments with vitamin C. The effective concentration of vitamin C inhibiting the growth of most E. coli and Klebsiella spp. isolates (90%) was estimated at 1.25 mg/ml and 2.5 mg/ml respectively, while for allStaphylococcus spp. isolates, it was 0.325 mg/ml. Vitamin C exhibited a notable anti-biofilm effect against the studied isolates, with biofilm prevention concentrations (BPC) of 0.625, 1.25, and 0.16 mg/ml for E. coli, Klebsiella spp., and Staphylococcus spp. isolates respectively. Furthermore, when combined with oxacillin or amoxicillin - drugs that were found ineffective, vitamin C significantly reduced the ability of MDR isolates to form biofilms, rendering them susceptible to the drugs' effects and restoring their efficacy. The expression of the recA gene, an early and quantifiable marker for the onset of the SOS response and biofilm production was downregulated after treatment of E. coli with vitamin C. Relative gene expression analysis revealed that ciprofloxacin-induced recA expression was significantly inhibited when MDR isolates of E. coli were treated with vitamin C at a concentration of 0.625 mg/ml, the BPC of vitamin C.
CONCLUSION: Our findings reveal that vitamin C, alone or in combination with ineffective antibiotics, attenuates biofilm formation and restores the susceptibility of multidrug-resistant (MDR) isolates to antimicrobial agents. This study underscores the promise of vitamin C as a non-lethal disruptor of biofilm-associated antimicrobial resistance.
CLINICAL TRIAL NUMBER: Not applicable.
Additional Links: PMID-40221679
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Citation:
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@article {pmid40221679,
year = {2025},
author = {Rahim, S and Rahman, R and Jhuma, TA and Ayub, M and Khan, SN and Hossain, A and Karim, MM},
title = {Disrupting antimicrobial resistance: unveiling the potential of vitamin C in combating biofilm formation in drug-resistant bacteria.},
journal = {BMC microbiology},
volume = {25},
number = {1},
pages = {212},
pmid = {40221679},
issn = {1471-2180},
support = {39.00.0000.009.99.024.22-901//Ministry of Science and Technology, Government of the People's Republic of Bangladesh/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Ascorbic Acid/pharmacology ; *Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; Humans ; *Drug Resistance, Multiple, Bacterial/drug effects ; *Bacteria/drug effects/isolation & purification/genetics ; Diabetic Foot/microbiology ; Escherichia coli/drug effects ; Klebsiella/drug effects ; Staphylococcus/drug effects ; },
abstract = {BACKGROUND: Antimicrobial resistance (AMR) poses a significant threat to global health, exacerbated by the protective mechanisms of biofilms formed by drug-resistant bacteria. Extracellular polymeric substances (EPS) produced by bacteria in biofilms serve as a formidable shield, impeding the efficacy of antimicrobial agents. Here, we investigated the potential of vitamin C (sodium ascorbate) to disrupt biofilm formation in drug-resistant bacteria isolated from diabetic foot ulcer (DFU) patients and studied the antimicrobial and antibiofilm activity of vitamin C on these bacteria.
RESULTS: Out of 117 study isolates, primarily identified as Escherichia coli (n = 52), Staphylococcus spp. (n = 19), and Klebsiella spp. (n = 46), 80 isolates exhibited a Multiple Antimicrobial Resistance (MAR) index greater than 0.2, classifying them as multi-drug resistant (MDR) superbugs. Among these, 58 isolates demonstrated moderate to strong biofilm-forming abilities and were selected for further experiments with vitamin C. The effective concentration of vitamin C inhibiting the growth of most E. coli and Klebsiella spp. isolates (90%) was estimated at 1.25 mg/ml and 2.5 mg/ml respectively, while for allStaphylococcus spp. isolates, it was 0.325 mg/ml. Vitamin C exhibited a notable anti-biofilm effect against the studied isolates, with biofilm prevention concentrations (BPC) of 0.625, 1.25, and 0.16 mg/ml for E. coli, Klebsiella spp., and Staphylococcus spp. isolates respectively. Furthermore, when combined with oxacillin or amoxicillin - drugs that were found ineffective, vitamin C significantly reduced the ability of MDR isolates to form biofilms, rendering them susceptible to the drugs' effects and restoring their efficacy. The expression of the recA gene, an early and quantifiable marker for the onset of the SOS response and biofilm production was downregulated after treatment of E. coli with vitamin C. Relative gene expression analysis revealed that ciprofloxacin-induced recA expression was significantly inhibited when MDR isolates of E. coli were treated with vitamin C at a concentration of 0.625 mg/ml, the BPC of vitamin C.
CONCLUSION: Our findings reveal that vitamin C, alone or in combination with ineffective antibiotics, attenuates biofilm formation and restores the susceptibility of multidrug-resistant (MDR) isolates to antimicrobial agents. This study underscores the promise of vitamin C as a non-lethal disruptor of biofilm-associated antimicrobial resistance.
CLINICAL TRIAL NUMBER: Not applicable.},
}
MeSH Terms:
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hide MeSH Terms
*Biofilms/drug effects/growth & development
*Ascorbic Acid/pharmacology
*Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests
Humans
*Drug Resistance, Multiple, Bacterial/drug effects
*Bacteria/drug effects/isolation & purification/genetics
Diabetic Foot/microbiology
Escherichia coli/drug effects
Klebsiella/drug effects
Staphylococcus/drug effects
RevDate: 2025-04-15
Extraradicular Infection and Apical Mineralized Biofilm: A Systematic Review of Published Case Reports.
Journal of clinical medicine, 14(7):.
Background/Objectives: Bacterial biofilms on root surfaces outside the apical foramen are linked to refractory apical periodontitis, as microorganisms can survive in extraradicular areas and cause persistent infections. This study aimed to precisely evaluate the relationship between extraradicular biofilm and persistent periapical periodontitis through an overview of case reports. Methods: A systematic search of PubMed, Web of Science, Scopus, Embase and ScienceDirect databases was conducted up to June 2023. Keywords included "extraradicular infection", "wet canal", "wet canals", "extraradicular mineralized biofilms", and "calculus-like deposit". Only case reports meeting the inclusion criteria were analyzed. Results: Fifteen cases of extraradicular infection were identified, involving eight women and six men aged between 18 and 60 years. These cases included nine failed treatments confirmed through complementary methods such as histobacteriologic analysis, scanning electron microscopy (SEM), or polymerase chain reaction (PCR). Among these, four patients (six teeth) exhibited calculus-like deposits. Conclusions: Extraradicular biofilm is strongly associated with failed endodontic treatments, leading to persistent infections. A structured decision-making approach is essential. Before considering apical surgery, clinicians should prioritize intraradicular infection control through thorough irrigation, antimicrobial medicaments, and adjunctive disinfection techniques. When extraradicular biofilms or mineralized calculus are present, and symptoms persist after optimal intracanal disinfection, apical surgery should be performed.
Additional Links: PMID-40217783
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@article {pmid40217783,
year = {2025},
author = {Pérez, AR and Rendón, J and Ortolani-Seltenerich, PS and Pérez-Ron, Y and Cardoso, M and Noites, R and Loroño, G and Vieira, GCS},
title = {Extraradicular Infection and Apical Mineralized Biofilm: A Systematic Review of Published Case Reports.},
journal = {Journal of clinical medicine},
volume = {14},
number = {7},
pages = {},
pmid = {40217783},
issn = {2077-0383},
abstract = {Background/Objectives: Bacterial biofilms on root surfaces outside the apical foramen are linked to refractory apical periodontitis, as microorganisms can survive in extraradicular areas and cause persistent infections. This study aimed to precisely evaluate the relationship between extraradicular biofilm and persistent periapical periodontitis through an overview of case reports. Methods: A systematic search of PubMed, Web of Science, Scopus, Embase and ScienceDirect databases was conducted up to June 2023. Keywords included "extraradicular infection", "wet canal", "wet canals", "extraradicular mineralized biofilms", and "calculus-like deposit". Only case reports meeting the inclusion criteria were analyzed. Results: Fifteen cases of extraradicular infection were identified, involving eight women and six men aged between 18 and 60 years. These cases included nine failed treatments confirmed through complementary methods such as histobacteriologic analysis, scanning electron microscopy (SEM), or polymerase chain reaction (PCR). Among these, four patients (six teeth) exhibited calculus-like deposits. Conclusions: Extraradicular biofilm is strongly associated with failed endodontic treatments, leading to persistent infections. A structured decision-making approach is essential. Before considering apical surgery, clinicians should prioritize intraradicular infection control through thorough irrigation, antimicrobial medicaments, and adjunctive disinfection techniques. When extraradicular biofilms or mineralized calculus are present, and symptoms persist after optimal intracanal disinfection, apical surgery should be performed.},
}
RevDate: 2025-04-14
CmpDate: 2025-04-11
Modulation of biofilm growth by shear and fluctuations in turbulent environments.
Scientific reports, 15(1):12460.
This work investigates the role of shear and turbulent fluctuations on multi-species biofilm growth. The study is mostly motivated by understanding biofouling on microplastics (MPs) in oceanic environments. By increasing particle stickiness, biofilms promote MP aggregation and sinking; therefore, a thorough understanding of this multi-scale process is crucial to improve predictions of the MPs fate. We conducted a series of laboratory experiments using an oscillating-grid system to promote biofilm growth on small plastic surfaces under homogeneous isotropic turbulence with grid Reynolds numbers between 305 and 2220. Two configurations were analyzed: one where plastic samples move along with the grid (shear-dominated) and another one where the samples are kept fixed downstream the grid, thus experiencing turbulence but no mean flow (shear-free). Biofilm formed in all cases in a time scale of days, then the biomass formed on the plastic pieces was carefully measured and analyzed as a function of the turbulence level. The shear-free results were further interpreted using a parsimonious physical model, coupling the nutrient uptake rate within the biofilm (Monod kinetics) with the turbulent diffusion of the surrounding bulk liquid. Results show that: (i) under shear-dominated conditions, the biofilm mass initially grows with turbulence intensity before decaying, presumably due to shear-induced erosion; (ii) in the shear-free experiments, the mass increases monotonically following an enhanced availability of nutrients, and then saturates due to uptake-limited kinetics. This latter behavior is well reproduced by the physical model. Furthermore, a subset of plastic pieces were analyzed with a scanning electron microscope, revealing that turbulence also affects the microscopic configuration of biofilm clusters, increasing their compactness as the amplitude of turbulent fluctuations increases. These results contribute not only to our fundamental understanding of biofilms under flow, but can also inform global models of MP transport in marine environments.
Additional Links: PMID-40216844
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Citation:
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@article {pmid40216844,
year = {2025},
author = {Pizzi, F and Peters, F and Sorribes, E and Marín-Beltrán, I and Romera-Castillo, C and Grau, J and Rahmani, M and Jofre, L and Capuano, F},
title = {Modulation of biofilm growth by shear and fluctuations in turbulent environments.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {12460},
pmid = {40216844},
issn = {2045-2322},
support = {TED2021-132623A-I00//Agencia Estatal de Investigación/ ; TED2021-132623A-I00//Agencia Estatal de Investigación/ ; TED2021-132623A-I00//Agencia Estatal de Investigación/ ; TED2021-132623A-I00//Agencia Estatal de Investigación/ ; TED2021-132623A-I00//Agencia Estatal de Investigación/ ; TED2021-132623A-I00//Agencia Estatal de Investigación/ ; TED2021-132623A-I00//Agencia Estatal de Investigación/ ; },
mesh = {*Biofilms/growth & development ; Microplastics ; Biomass ; Biofouling ; },
abstract = {This work investigates the role of shear and turbulent fluctuations on multi-species biofilm growth. The study is mostly motivated by understanding biofouling on microplastics (MPs) in oceanic environments. By increasing particle stickiness, biofilms promote MP aggregation and sinking; therefore, a thorough understanding of this multi-scale process is crucial to improve predictions of the MPs fate. We conducted a series of laboratory experiments using an oscillating-grid system to promote biofilm growth on small plastic surfaces under homogeneous isotropic turbulence with grid Reynolds numbers between 305 and 2220. Two configurations were analyzed: one where plastic samples move along with the grid (shear-dominated) and another one where the samples are kept fixed downstream the grid, thus experiencing turbulence but no mean flow (shear-free). Biofilm formed in all cases in a time scale of days, then the biomass formed on the plastic pieces was carefully measured and analyzed as a function of the turbulence level. The shear-free results were further interpreted using a parsimonious physical model, coupling the nutrient uptake rate within the biofilm (Monod kinetics) with the turbulent diffusion of the surrounding bulk liquid. Results show that: (i) under shear-dominated conditions, the biofilm mass initially grows with turbulence intensity before decaying, presumably due to shear-induced erosion; (ii) in the shear-free experiments, the mass increases monotonically following an enhanced availability of nutrients, and then saturates due to uptake-limited kinetics. This latter behavior is well reproduced by the physical model. Furthermore, a subset of plastic pieces were analyzed with a scanning electron microscope, revealing that turbulence also affects the microscopic configuration of biofilm clusters, increasing their compactness as the amplitude of turbulent fluctuations increases. These results contribute not only to our fundamental understanding of biofilms under flow, but can also inform global models of MP transport in marine environments.},
}
MeSH Terms:
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*Biofilms/growth & development
Microplastics
Biomass
Biofouling
RevDate: 2025-04-14
CmpDate: 2025-04-11
Temporal Beta Diversity of Bacteria in Streams: Network Position Matters But Differently for Bacterioplankton and Biofilm Communities.
Microbial ecology, 88(1):26.
Concern about biodiversity loss has yielded a surge of studies on temporal change in α-diversity, whereas temporal β-diversity has gained less interest. We sampled bacterioplankton, biofilm, and riparian soil bacteria repeatedly across the open-water season in a pristine stream network to determine the level of temporal β-diversity in relation to stream network position and environmental variability. We tested the hypothesis that aquatic bacterial communities in isolated and environmentally heterogenous headwaters exhibit high temporal β-diversity while the better-connected and environmentally more stable mainstem sections support more stable communities, and soil communities bear no relationship to network position. As expected, temporal β-diversity decreased from headwaters toward mainstems for bacterioplankton. Against expectations, an opposite pattern was observed for biofilm. For bacterioplankton, temporal β-diversity was positively related to temporal variability in water chemistry. For biofilm bacteria, temporal variability was negatively related to variability in temperature. Temporal β-diversity of soil communities did not show any response to stream network position, but was strongly related to variability in the soil environment. The two aquatic habitats and riparian soils supported distinctly different bacterial communities. The number of ASVs shared between the soil and the aquatic communities decreased along the network, and more so for bacterioplankton. The higher temporal variability of bacterial communities in the headwaters likely results from temporally variable input of propagules from riparian soil, emphasizing the role of land-water connection and network position to bacterioplankton community composition. Overall, bacterial communities exhibited high temporal variability, highlighting the importance of temporal replication to fully capture their network-scale biodiversity.
Additional Links: PMID-40216640
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Citation:
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@article {pmid40216640,
year = {2025},
author = {Huttunen, KL and Malazarte, J and Jyväsjärvi, J and Lehosmaa, K and Muotka, T},
title = {Temporal Beta Diversity of Bacteria in Streams: Network Position Matters But Differently for Bacterioplankton and Biofilm Communities.},
journal = {Microbial ecology},
volume = {88},
number = {1},
pages = {26},
pmid = {40216640},
issn = {1432-184X},
support = {356403//Research Council of Finland/ ; 318230//Research Council of Finland/ ; 318230//Research Council of Finland/ ; },
mesh = {*Biofilms/growth & development ; *Rivers/microbiology/chemistry ; *Bacteria/classification/genetics/isolation & purification ; *Biodiversity ; *Plankton/classification/genetics ; Soil Microbiology ; Ecosystem ; Seasons ; },
abstract = {Concern about biodiversity loss has yielded a surge of studies on temporal change in α-diversity, whereas temporal β-diversity has gained less interest. We sampled bacterioplankton, biofilm, and riparian soil bacteria repeatedly across the open-water season in a pristine stream network to determine the level of temporal β-diversity in relation to stream network position and environmental variability. We tested the hypothesis that aquatic bacterial communities in isolated and environmentally heterogenous headwaters exhibit high temporal β-diversity while the better-connected and environmentally more stable mainstem sections support more stable communities, and soil communities bear no relationship to network position. As expected, temporal β-diversity decreased from headwaters toward mainstems for bacterioplankton. Against expectations, an opposite pattern was observed for biofilm. For bacterioplankton, temporal β-diversity was positively related to temporal variability in water chemistry. For biofilm bacteria, temporal variability was negatively related to variability in temperature. Temporal β-diversity of soil communities did not show any response to stream network position, but was strongly related to variability in the soil environment. The two aquatic habitats and riparian soils supported distinctly different bacterial communities. The number of ASVs shared between the soil and the aquatic communities decreased along the network, and more so for bacterioplankton. The higher temporal variability of bacterial communities in the headwaters likely results from temporally variable input of propagules from riparian soil, emphasizing the role of land-water connection and network position to bacterioplankton community composition. Overall, bacterial communities exhibited high temporal variability, highlighting the importance of temporal replication to fully capture their network-scale biodiversity.},
}
MeSH Terms:
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*Biofilms/growth & development
*Rivers/microbiology/chemistry
*Bacteria/classification/genetics/isolation & purification
*Biodiversity
*Plankton/classification/genetics
Soil Microbiology
Ecosystem
Seasons
RevDate: 2025-04-12
Glycosylation of oral bacteria in modulating adhesion and biofilm formation.
Journal of oral microbiology, 17(1):2486650.
BACKGROUND: Glycosylation is a ubiquitous biochemical process that covalently attaches glycans to proteins or lipids, which plays a pivotal role in modulating the structure and function of these biomolecules. This post-translational modification is prevalent in living organisms and intricately regulates various biological processes, including signaling transduction, recognition, and immune responses. In the oral environment, bacteria ingeniously use glycosylation to enhance their adhesion to oral surfaces, which is a key step in biofilm formation and subsequent development. This adhesion process is intimately associated with the onset and progression of oral diseases, including dental caries and periodontal disease.
OBJECTIVE: This review aims to describe the types and mechanisms of glycosylation in oral bacteria, and to understand the role of glycosylation in the adhesion, biofilm formation and virulence of oral bacteria.
METHODS: We reviewed articles on glycosylation in a variety of oral bacteria.
CONCLUSION: In cariogenic bacteria and periodontopathic pathogens, glycosylation facilitates adhesion and subsequent biofilm maturation on tooth surface. Distinct glycosylation patterns in oral bacteria shape biofilm structure and function, influencing microbial interactions and community stability. Pathogen-specific glycosylation signatures enhance virulence and ecological competitiveness, contributing to disease progression. Glycosylation plays a critical role in bacterial virulence and community interactions, with significant implications for oral health and disease development.
Additional Links: PMID-40213769
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@article {pmid40213769,
year = {2025},
author = {Yi, S and Liu, Y and Wu, Q and Zhao, D and Li, Z and Peng, X and Liao, G and Wang, S},
title = {Glycosylation of oral bacteria in modulating adhesion and biofilm formation.},
journal = {Journal of oral microbiology},
volume = {17},
number = {1},
pages = {2486650},
pmid = {40213769},
issn = {2000-2297},
abstract = {BACKGROUND: Glycosylation is a ubiquitous biochemical process that covalently attaches glycans to proteins or lipids, which plays a pivotal role in modulating the structure and function of these biomolecules. This post-translational modification is prevalent in living organisms and intricately regulates various biological processes, including signaling transduction, recognition, and immune responses. In the oral environment, bacteria ingeniously use glycosylation to enhance their adhesion to oral surfaces, which is a key step in biofilm formation and subsequent development. This adhesion process is intimately associated with the onset and progression of oral diseases, including dental caries and periodontal disease.
OBJECTIVE: This review aims to describe the types and mechanisms of glycosylation in oral bacteria, and to understand the role of glycosylation in the adhesion, biofilm formation and virulence of oral bacteria.
METHODS: We reviewed articles on glycosylation in a variety of oral bacteria.
CONCLUSION: In cariogenic bacteria and periodontopathic pathogens, glycosylation facilitates adhesion and subsequent biofilm maturation on tooth surface. Distinct glycosylation patterns in oral bacteria shape biofilm structure and function, influencing microbial interactions and community stability. Pathogen-specific glycosylation signatures enhance virulence and ecological competitiveness, contributing to disease progression. Glycosylation plays a critical role in bacterial virulence and community interactions, with significant implications for oral health and disease development.},
}
RevDate: 2025-04-12
The biofilm matrix protects Bacillu subtilis against hydrogen peroxide.
Biofilm, 9:100274.
Biofilms formed by Bacillus subtilis confer protection against environmental stressors through extracellular polysaccharides (EPS) and sporulation. This study investigates the roles of these biofilm components in resistance to hydrogen peroxide, a common reactive oxygen species source and disinfectant. Using wild-type and mutant strains deficient in EPS or sporulation, biofilm colonies were cultivated at various maturation stages and exposed to hydrogen peroxide. EPS-deficient biofilms exhibited reduced resilience, particularly in early stages, highlighting the structural and protective importance of the matrix. Mature biofilms demonstrated additional protective mechanisms, potentially involving TasA protein fibers and/or the biofilm surface layer (BslA). In contrast, sporulation showed limited contribution to hydrogen peroxide resistance, as survival was primarily matrix-dependent. These findings underscore the necessity of targeting EPS and other matrix components in anti-biofilm strategies, suggesting that hydrogen peroxide-based disinfection could be enhanced by combining it with complementary sporicidal treatments. This study advances our understanding of biofilm resilience, contributing to the development of more effective sterilization protocols.
Additional Links: PMID-40212916
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Citation:
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@article {pmid40212916,
year = {2025},
author = {Muratov, E and Keilholz, J and Kovács, ÁT and Moeller, R},
title = {The biofilm matrix protects Bacillu subtilis against hydrogen peroxide.},
journal = {Biofilm},
volume = {9},
number = {},
pages = {100274},
pmid = {40212916},
issn = {2590-2075},
abstract = {Biofilms formed by Bacillus subtilis confer protection against environmental stressors through extracellular polysaccharides (EPS) and sporulation. This study investigates the roles of these biofilm components in resistance to hydrogen peroxide, a common reactive oxygen species source and disinfectant. Using wild-type and mutant strains deficient in EPS or sporulation, biofilm colonies were cultivated at various maturation stages and exposed to hydrogen peroxide. EPS-deficient biofilms exhibited reduced resilience, particularly in early stages, highlighting the structural and protective importance of the matrix. Mature biofilms demonstrated additional protective mechanisms, potentially involving TasA protein fibers and/or the biofilm surface layer (BslA). In contrast, sporulation showed limited contribution to hydrogen peroxide resistance, as survival was primarily matrix-dependent. These findings underscore the necessity of targeting EPS and other matrix components in anti-biofilm strategies, suggesting that hydrogen peroxide-based disinfection could be enhanced by combining it with complementary sporicidal treatments. This study advances our understanding of biofilm resilience, contributing to the development of more effective sterilization protocols.},
}
RevDate: 2025-04-12
Decoding the impact of interspecies interactions on biofilm matrix components.
Biofilm, 9:100271.
Multispecies biofilms are complex communities where extracellular polymeric substances (EPS) shape structure, adaptability, and functionality. However, characterizing the components of EPS, particularly glycans and proteins, remains a challenge due to the diverse bacterial species present and their interactions within the matrix. This study examined how interactions between different species affect EPS component composition and spatial organization. We analyzed a consortium of four bacterial soil isolates that have previously demonstrated various intrinsic properties in biofilm communities: Microbacterium oxydans, Paenibacillus amylolyticus, Stenotrophomonas rhizophila, and Xanthomonas retroflexus. We used fluorescence lectin binding analysis to identify specific glycan components and meta-proteomics to characterize matrix proteins in mono- and multispecies biofilms. Our results revealed diverse glycan structures and composition, including fucose and different amino sugar-containing polymers, with substantial differences between monospecies and multispecies biofilms. In isolation, M. oxydans produced galactose/N-Acetylgalactosamine network-like structures and influenced the matrix composition in multispecies biofilms. Proteomic analysis revealed presence of flagellin proteins in X. retroflexus and P. amylolyticus, particularly in multispecies biofilms. Additionally, surface-layer proteins and a unique peroxidase were identified in P. amylolyticus multispecies biofilms, indicating enhanced oxidative stress resistance and structural stability under these conditions. This study highlights the crucial role of interspecies interactions in shaping the biofilm matrix, as well as the production of glycans and proteins, thereby enhancing our understanding of biofilm complexity.
Additional Links: PMID-40212915
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@article {pmid40212915,
year = {2025},
author = {Amador, CI and Røder, HL and Herschend, J and Neu, TR and Burmølle, M},
title = {Decoding the impact of interspecies interactions on biofilm matrix components.},
journal = {Biofilm},
volume = {9},
number = {},
pages = {100271},
pmid = {40212915},
issn = {2590-2075},
abstract = {Multispecies biofilms are complex communities where extracellular polymeric substances (EPS) shape structure, adaptability, and functionality. However, characterizing the components of EPS, particularly glycans and proteins, remains a challenge due to the diverse bacterial species present and their interactions within the matrix. This study examined how interactions between different species affect EPS component composition and spatial organization. We analyzed a consortium of four bacterial soil isolates that have previously demonstrated various intrinsic properties in biofilm communities: Microbacterium oxydans, Paenibacillus amylolyticus, Stenotrophomonas rhizophila, and Xanthomonas retroflexus. We used fluorescence lectin binding analysis to identify specific glycan components and meta-proteomics to characterize matrix proteins in mono- and multispecies biofilms. Our results revealed diverse glycan structures and composition, including fucose and different amino sugar-containing polymers, with substantial differences between monospecies and multispecies biofilms. In isolation, M. oxydans produced galactose/N-Acetylgalactosamine network-like structures and influenced the matrix composition in multispecies biofilms. Proteomic analysis revealed presence of flagellin proteins in X. retroflexus and P. amylolyticus, particularly in multispecies biofilms. Additionally, surface-layer proteins and a unique peroxidase were identified in P. amylolyticus multispecies biofilms, indicating enhanced oxidative stress resistance and structural stability under these conditions. This study highlights the crucial role of interspecies interactions in shaping the biofilm matrix, as well as the production of glycans and proteins, thereby enhancing our understanding of biofilm complexity.},
}
RevDate: 2025-04-12
Glucosyltransferase activity-based screening identifies tannic acid as an inhibitor of Streptococcus mutans biofilm.
Frontiers in microbiology, 16:1555497.
Dental caries is a biofilm-related chronic infectious disease. Streptococcus mutans is the core microorganism that leads to caries, with its capacity to form biofilms via glucosyltransferases (Gtfs) being the predominant virulence factor contributing to this condition. Therefore, researching novel drugs targeting Gtf is important for treating dental caries. Our study established a rapid detection method for Gtf activity to screen over 1,000 compounds from the Selleck Natural Product Library. We identified tannic acid (TA) as a potential inhibitor of Gtf activity. In vitro experiments suggested that TA could inhibit extracellular polysaccharide (EPS) synthesis and biofilm formation in S. mutans by selectively antagonizing Gtf rather than directly killing the bacteria. Molecular docking experiments confirmed a strong binding affinity between TA and Gtf. In summary, TA exhibits good anti-virulence performance against S. mutans, indicating its potential value in anti-biofilm and anti-caries applications.
Additional Links: PMID-40212388
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@article {pmid40212388,
year = {2025},
author = {Xu, M and Wang, X and Gong, T and Yang, Z and Zhang, D and Ma, Q and Li, Y},
title = {Glucosyltransferase activity-based screening identifies tannic acid as an inhibitor of Streptococcus mutans biofilm.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1555497},
pmid = {40212388},
issn = {1664-302X},
abstract = {Dental caries is a biofilm-related chronic infectious disease. Streptococcus mutans is the core microorganism that leads to caries, with its capacity to form biofilms via glucosyltransferases (Gtfs) being the predominant virulence factor contributing to this condition. Therefore, researching novel drugs targeting Gtf is important for treating dental caries. Our study established a rapid detection method for Gtf activity to screen over 1,000 compounds from the Selleck Natural Product Library. We identified tannic acid (TA) as a potential inhibitor of Gtf activity. In vitro experiments suggested that TA could inhibit extracellular polysaccharide (EPS) synthesis and biofilm formation in S. mutans by selectively antagonizing Gtf rather than directly killing the bacteria. Molecular docking experiments confirmed a strong binding affinity between TA and Gtf. In summary, TA exhibits good anti-virulence performance against S. mutans, indicating its potential value in anti-biofilm and anti-caries applications.},
}
RevDate: 2025-04-12
New insights in the role of Candida biofilm in the pathogenesis of recurrent vulvovaginal candidiasis: a prospective clinical study.
Frontiers in microbiology, 16:1566171.
BACKGROUND: Despite the pathogenesis of vulvovaginal candidiasis (VVC) is multifactorial, this study aimed to assess whether phenotypic characteristics, such as biofilm production and quality, along with clinical symptoms, are associated with recurrent VVC (RVVC).
METHODS: Over 1 year (Oct 2021-Oct 2022), we prospectively included 271 patients ≥18 years who attended our institution, had Candida spp. isolated in vaginal swabs, and provided informed consent. Patients were followed for 1 year. Candida spp. isolates were tested by the following techniques: crystal violet (CV) for biomass quantification, XTT for metabolic activity quantification, and microscopy for biofilm area quantification. Clinical and microbiological data were also collected.
RESULTS: Overall, 55 (20.3%) patients experienced at least one recurrence, with 19 (7.0%) meeting the criteria for RVVC (≥3 episodes/year), with 65 episodes in total. Demographic and clinical characteristics were similar in both study groups. Most isolates were C. albicans (90.0%). Median (interquartile, [IQR]) absorbance values for CV and XTT in 18/19 RVVC and 238/252 non-RVVC isolates were as follows: CV, 1.850 (1.578-2.156) vs. 1.426 (1.081-1.823), p = 0.005; XTT, 0.184 (0.116-0.293) vs. 0.228 (0.147-0.331), p = 0.253. Median (IQR) biofilm occupation area percentage in 16/19 RVVC and 16/252 non-RVVC isolates was, respectively: 13.15 (8.54-16.9) and 10.73 (5.88-17.73), p = 0.710.
CONCLUSION: RVVC was associated to high biomass production. Additionally, RVVC clinical isolates exhibited a tendency toward lower metabolic activity, which may contribute to treatment failure.
Additional Links: PMID-40212387
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@article {pmid40212387,
year = {2025},
author = {Díaz-Navarro, M and Irigoyen-von-Sierakowski, Á and Delcán, I and Monte, A and Palomo, M and Escribano, P and Guinea, J and Burillo, A and Galar, A and Muñoz, P and Guembe, M},
title = {New insights in the role of Candida biofilm in the pathogenesis of recurrent vulvovaginal candidiasis: a prospective clinical study.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1566171},
pmid = {40212387},
issn = {1664-302X},
abstract = {BACKGROUND: Despite the pathogenesis of vulvovaginal candidiasis (VVC) is multifactorial, this study aimed to assess whether phenotypic characteristics, such as biofilm production and quality, along with clinical symptoms, are associated with recurrent VVC (RVVC).
METHODS: Over 1 year (Oct 2021-Oct 2022), we prospectively included 271 patients ≥18 years who attended our institution, had Candida spp. isolated in vaginal swabs, and provided informed consent. Patients were followed for 1 year. Candida spp. isolates were tested by the following techniques: crystal violet (CV) for biomass quantification, XTT for metabolic activity quantification, and microscopy for biofilm area quantification. Clinical and microbiological data were also collected.
RESULTS: Overall, 55 (20.3%) patients experienced at least one recurrence, with 19 (7.0%) meeting the criteria for RVVC (≥3 episodes/year), with 65 episodes in total. Demographic and clinical characteristics were similar in both study groups. Most isolates were C. albicans (90.0%). Median (interquartile, [IQR]) absorbance values for CV and XTT in 18/19 RVVC and 238/252 non-RVVC isolates were as follows: CV, 1.850 (1.578-2.156) vs. 1.426 (1.081-1.823), p = 0.005; XTT, 0.184 (0.116-0.293) vs. 0.228 (0.147-0.331), p = 0.253. Median (IQR) biofilm occupation area percentage in 16/19 RVVC and 16/252 non-RVVC isolates was, respectively: 13.15 (8.54-16.9) and 10.73 (5.88-17.73), p = 0.710.
CONCLUSION: RVVC was associated to high biomass production. Additionally, RVVC clinical isolates exhibited a tendency toward lower metabolic activity, which may contribute to treatment failure.},
}
RevDate: 2025-04-12
Effective treatment of oral microbial infections and biofilm using flavonoid rutin - An in vitro study.
Journal of oral biology and craniofacial research, 15(3):541-547.
BACKGROUND: Oral microbial infections and biofilm-associated conditions, such as dental caries, gingivitis, and periodontitis, remain major challenges in oral healthcare. Biofilms provide resistance to conventional antimicrobial treatments, necessitating innovative solutions. This study investigates rutin, a flavonoid glycoside, for its antimicrobial and antibiofilm properties against key oral pathogens.
AIM: To evaluate the antibacterial and antibiofilm efficacy of rutin against oral pathogens, including Streptococcus mutans, Pseudomonas aeruginosa, and Candida albicans, and assess its hemocompatibility as a safe therapeutic agent.
METHODOLOGY: Oral pathogens were isolated from clinical samples and identified using the VITEK®2 Compact System. Antimicrobial activity of five flavonoids was screened using the well diffusion method, with rutin demonstrating the highest efficacy. Minimum inhibitory concentration (MIC) and antibiofilm activity were assessed using broth microdilution and crystal violet staining, respectively. Confocal Laser Scanning Microscopy analyzed live/dead cells in treated biofilms. Hemocompatibility was evaluated via a hemolysis assay.
RESULTS: Rutin exhibited significant antimicrobial activity with zone of inhibition as 19 mm (C. albicans), 17 mm (P. aeruginosa), and 17 mm (S. mutans). MIC against mixed biofilms was 10 mM, while treatment at 2 × MIC reduced biofilm biomass by 92 %. Live/dead analysis confirmed extensive microbial cell death in biofilms. Hemolysis rates below 5 % established rutin's biocompatibility.
CONCLUSION: Rutin demonstrates potent antimicrobial and antibiofilm efficacy with excellent safety, suggesting its potential as an alternative therapy for biofilm-associated oral infections. Further in vivo studies are warranted to validate these findings.
Additional Links: PMID-40212100
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Citation:
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@article {pmid40212100,
year = {2025},
author = {Sowmya, KP and Surenthar, M and Lekha Sree, V},
title = {Effective treatment of oral microbial infections and biofilm using flavonoid rutin - An in vitro study.},
journal = {Journal of oral biology and craniofacial research},
volume = {15},
number = {3},
pages = {541-547},
pmid = {40212100},
issn = {2212-4268},
abstract = {BACKGROUND: Oral microbial infections and biofilm-associated conditions, such as dental caries, gingivitis, and periodontitis, remain major challenges in oral healthcare. Biofilms provide resistance to conventional antimicrobial treatments, necessitating innovative solutions. This study investigates rutin, a flavonoid glycoside, for its antimicrobial and antibiofilm properties against key oral pathogens.
AIM: To evaluate the antibacterial and antibiofilm efficacy of rutin against oral pathogens, including Streptococcus mutans, Pseudomonas aeruginosa, and Candida albicans, and assess its hemocompatibility as a safe therapeutic agent.
METHODOLOGY: Oral pathogens were isolated from clinical samples and identified using the VITEK®2 Compact System. Antimicrobial activity of five flavonoids was screened using the well diffusion method, with rutin demonstrating the highest efficacy. Minimum inhibitory concentration (MIC) and antibiofilm activity were assessed using broth microdilution and crystal violet staining, respectively. Confocal Laser Scanning Microscopy analyzed live/dead cells in treated biofilms. Hemocompatibility was evaluated via a hemolysis assay.
RESULTS: Rutin exhibited significant antimicrobial activity with zone of inhibition as 19 mm (C. albicans), 17 mm (P. aeruginosa), and 17 mm (S. mutans). MIC against mixed biofilms was 10 mM, while treatment at 2 × MIC reduced biofilm biomass by 92 %. Live/dead analysis confirmed extensive microbial cell death in biofilms. Hemolysis rates below 5 % established rutin's biocompatibility.
CONCLUSION: Rutin demonstrates potent antimicrobial and antibiofilm efficacy with excellent safety, suggesting its potential as an alternative therapy for biofilm-associated oral infections. Further in vivo studies are warranted to validate these findings.},
}
RevDate: 2025-04-10
Bacteriocin Isolated from Ralstonia mannitolilytica and Bacteriocin-Capped Silver Nanoparticles: Comparative Effects on Biofilm Formation and LuxS Gene's Expressions by Proteus mirabilis as an Approach to Counter MDR Catheter Infection.
Microbial pathogenesis pii:S0882-4010(25)00283-9 [Epub ahead of print].
Among undesirable situation in treating certain infections and diseases is the contamination of catheters, especially with the microbes' resistance to drugs. The situation has necessitated the search for alternative antimicrobial agents. Bacteriocin category, antibiotic originate, peptide-natured, Ralstonia mannitolilytica microbes-produced, bacteriocin material, and the semi-pure bacteriocin capped silver metal nanoparticles (AgNPs) were used for combating the MDR (multi drug resistance) organism, Proteus mirabilis, which is the third-most common cause of UTI (urinary tract infection), and that is linked to catheter use, are being recommended for clinical use with certain development. The crude microbial product was isolated from the microbial entity, Ralstonia mannitolilytica, which grows in crude petroleum-contaminated soil, and was semi-purified for use in the synthesis of the bacteriocin-capped AgNPs. The prepared nanoparticles were characterized using X-ray diffraction, indicating the silver element's presence; field emission scanning electron microscopy, revealing near-spherical but irregular shapes of the bacteriocin-capped AgNPs with a size range of 34-46 nm; and atomic force microscopic analysis, which demonstrated the nanoparticles surface characteristics. The DLS analysis established the negative charge, and an average hydrodynamic size of 51 nm, while the UV-Vis spectroscopic analysis showed the absorption maxima (λmax) at 454 nm. The P. mirabilis isolates were numbered according to MDR detection by the VITEK 2 system (A to J), and the microbes appeared as a pale-coloured colony on MacConkey agar. The biofilm formation screening revealed the highest biofilm-producing isolates, termed as A, B, C, and D. The treatments with both bacteriocin and the bacteriocin-capped AgNPs showed that bacteriocin effectively inhibited the biofilm formation for isolates A, B, and C, but isolate D was less affected. In addition, the LuxS gene-down-regulating effects of bacteriocin and bacteriocin-capped AgNPs were also observed. The expression of the LuxS gene in P. mirabilis was lowered by bacteriocin-capped AgNPs during biofilm formation, while the isolates B and C lowered their expressions of the LuxS gene more effectively when the bacteriocin was used.Conversely, the study recommends the use of bacteriocin-capped AgNPs for controlling and treating the possible catheter infection, which needs further development as a product and established clinical testing.
Additional Links: PMID-40210139
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PubMed:
Citation:
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@article {pmid40210139,
year = {2025},
author = {Ahmed, ME and Aljarbou, A and Mohammed, HA and Khan, RA},
title = {Bacteriocin Isolated from Ralstonia mannitolilytica and Bacteriocin-Capped Silver Nanoparticles: Comparative Effects on Biofilm Formation and LuxS Gene's Expressions by Proteus mirabilis as an Approach to Counter MDR Catheter Infection.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107558},
doi = {10.1016/j.micpath.2025.107558},
pmid = {40210139},
issn = {1096-1208},
abstract = {Among undesirable situation in treating certain infections and diseases is the contamination of catheters, especially with the microbes' resistance to drugs. The situation has necessitated the search for alternative antimicrobial agents. Bacteriocin category, antibiotic originate, peptide-natured, Ralstonia mannitolilytica microbes-produced, bacteriocin material, and the semi-pure bacteriocin capped silver metal nanoparticles (AgNPs) were used for combating the MDR (multi drug resistance) organism, Proteus mirabilis, which is the third-most common cause of UTI (urinary tract infection), and that is linked to catheter use, are being recommended for clinical use with certain development. The crude microbial product was isolated from the microbial entity, Ralstonia mannitolilytica, which grows in crude petroleum-contaminated soil, and was semi-purified for use in the synthesis of the bacteriocin-capped AgNPs. The prepared nanoparticles were characterized using X-ray diffraction, indicating the silver element's presence; field emission scanning electron microscopy, revealing near-spherical but irregular shapes of the bacteriocin-capped AgNPs with a size range of 34-46 nm; and atomic force microscopic analysis, which demonstrated the nanoparticles surface characteristics. The DLS analysis established the negative charge, and an average hydrodynamic size of 51 nm, while the UV-Vis spectroscopic analysis showed the absorption maxima (λmax) at 454 nm. The P. mirabilis isolates were numbered according to MDR detection by the VITEK 2 system (A to J), and the microbes appeared as a pale-coloured colony on MacConkey agar. The biofilm formation screening revealed the highest biofilm-producing isolates, termed as A, B, C, and D. The treatments with both bacteriocin and the bacteriocin-capped AgNPs showed that bacteriocin effectively inhibited the biofilm formation for isolates A, B, and C, but isolate D was less affected. In addition, the LuxS gene-down-regulating effects of bacteriocin and bacteriocin-capped AgNPs were also observed. The expression of the LuxS gene in P. mirabilis was lowered by bacteriocin-capped AgNPs during biofilm formation, while the isolates B and C lowered their expressions of the LuxS gene more effectively when the bacteriocin was used.Conversely, the study recommends the use of bacteriocin-capped AgNPs for controlling and treating the possible catheter infection, which needs further development as a product and established clinical testing.},
}
RevDate: 2025-04-10
Extraction and physiochemical characterization of micro-fibrillated cellulose based composite biofilm derived from Aegle marmelos fruit shells waste for packaging applications supported by in-silico docking studies.
International journal of biological macromolecules pii:S0141-8130(25)03473-7 [Epub ahead of print].
The utilization of waste shells from Aegle marmelos (bael) as a source of Micro fibrillated cellulose (MFC) was undertaken for applications in food packaging within the framework of this investigation. FTIR analysis of CAM and Raw Aegle marmelos shell powder (RAM) showed stretching of -OH and -CH groups at 3339 cm[-1] and 2889 cm-[1]. Our results showed that crystallinity indices of CAM and RAM were 39.59 % and 18.89 %, respectively indicating a significant raise in crystallinity after extraction. FTIR analysis reveals the presence of hydroxyl groups (3306 cm[-1]) in all films. Exploration of the results indicated the development of covalent and H (hydrogen) bonds between CAM and Guar gum/Chitosan (GT), as discerned through FT-IR studies. X-ray diffraction unveiled in the amorphous feature of the films following CAM into GT composite film. Evaluation through FE-SEM exhibited a densely disordered network contributing to a heightened contact angle of the resultant film with an enhanced concentration of CAM. Cellulose Iβ and Chitosan showed stronger binding affinity of -7.3 kcal/mol, suggesting greater compatibility and stability. The antioxidant capacity of the films increased from 10.90 to 61.80 due to addition of CAM in the GT mixture where elevated concentrations demonstrated better scavenging activity.
Additional Links: PMID-40210077
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PubMed:
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@article {pmid40210077,
year = {2025},
author = {Sonu, PK and Srivastav, AK and Anjali, and Peddireddy, V and Kumar, U},
title = {Extraction and physiochemical characterization of micro-fibrillated cellulose based composite biofilm derived from Aegle marmelos fruit shells waste for packaging applications supported by in-silico docking studies.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {142921},
doi = {10.1016/j.ijbiomac.2025.142921},
pmid = {40210077},
issn = {1879-0003},
abstract = {The utilization of waste shells from Aegle marmelos (bael) as a source of Micro fibrillated cellulose (MFC) was undertaken for applications in food packaging within the framework of this investigation. FTIR analysis of CAM and Raw Aegle marmelos shell powder (RAM) showed stretching of -OH and -CH groups at 3339 cm[-1] and 2889 cm-[1]. Our results showed that crystallinity indices of CAM and RAM were 39.59 % and 18.89 %, respectively indicating a significant raise in crystallinity after extraction. FTIR analysis reveals the presence of hydroxyl groups (3306 cm[-1]) in all films. Exploration of the results indicated the development of covalent and H (hydrogen) bonds between CAM and Guar gum/Chitosan (GT), as discerned through FT-IR studies. X-ray diffraction unveiled in the amorphous feature of the films following CAM into GT composite film. Evaluation through FE-SEM exhibited a densely disordered network contributing to a heightened contact angle of the resultant film with an enhanced concentration of CAM. Cellulose Iβ and Chitosan showed stronger binding affinity of -7.3 kcal/mol, suggesting greater compatibility and stability. The antioxidant capacity of the films increased from 10.90 to 61.80 due to addition of CAM in the GT mixture where elevated concentrations demonstrated better scavenging activity.},
}
RevDate: 2025-04-10
Phellodendron bark extract and berberine chloride suppress microbiome dysbiosis in a saliva-derived in vitro microcosm biofilm model.
Archives of oral biology, 174:106231 pii:S0003-9969(25)00059-7 [Epub ahead of print].
OBJECTIVE: Preventing oral microbiome dysbiosis is crucial for averting the onset and progression of periodontal diseases. Phellodendron bark extract (PBE) and its active component berberine exhibit antibacterial properties against periodontal pathogenic bacteria. Although they inhibit Porphyromonas gingivalis (P. gingivalis)-induced dysbiosis in vitro in multiple species of saliva-derived planktonic cultures, their effects on microcosm biofilm models remain unclear. In this study, we aimed to elucidate the dysbiosis-suppressive effects of PBE and berberine chloride (BC) on biofilm formation.
DESIGN: PBE or BC was added during the formation of in vitro microcosm biofilms containing saliva and P. gingivalis, which were anaerobically cultured for one week. Next-generation sequencing was performed to assess microbiota composition, while quantitative real-time PCR was used to measure bacterial concentrations. Additionally, the butyrate concentration in the culture supernatant was assessed as biofilm pathogenicity.
RESULTS: PBE and BC treatments reduced the relative abundance of periodontal pathogenic bacteria, including P. gingivalis, and significantly increased the relative abundance of the genus Streptococcus and nitrate-reducing bacteria, including the genera of Neisseria and Haemophilus. Moreover, the treatment groups exhibited significantly decreased butyrate concentrations.
CONCLUSIONS: Our findings suggest that PBE and BC could suppress dysbiosis triggered by P. gingivalis in microcosm biofilms in vitro by decreasing the relative abundance and amount of periodontal pathogenic bacteria and enhancing those of nitrate-reducing bacteria that have a high relative abundance in orally healthy individuals. In summary, PBE and BC may contribute to the prevention of periodontal disease through their dysbiosis-suppressive and anti-inflammatory effects.
Additional Links: PMID-40209653
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PubMed:
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@article {pmid40209653,
year = {2025},
author = {Inokuchi, T and Tomiyama, K and Okuda, T and Tsutsumi, K and Yama, K and Fujii, Y and Ohara, K and Chikazawa, T and Kakizawa, Y and Mukai, Y},
title = {Phellodendron bark extract and berberine chloride suppress microbiome dysbiosis in a saliva-derived in vitro microcosm biofilm model.},
journal = {Archives of oral biology},
volume = {174},
number = {},
pages = {106231},
doi = {10.1016/j.archoralbio.2025.106231},
pmid = {40209653},
issn = {1879-1506},
abstract = {OBJECTIVE: Preventing oral microbiome dysbiosis is crucial for averting the onset and progression of periodontal diseases. Phellodendron bark extract (PBE) and its active component berberine exhibit antibacterial properties against periodontal pathogenic bacteria. Although they inhibit Porphyromonas gingivalis (P. gingivalis)-induced dysbiosis in vitro in multiple species of saliva-derived planktonic cultures, their effects on microcosm biofilm models remain unclear. In this study, we aimed to elucidate the dysbiosis-suppressive effects of PBE and berberine chloride (BC) on biofilm formation.
DESIGN: PBE or BC was added during the formation of in vitro microcosm biofilms containing saliva and P. gingivalis, which were anaerobically cultured for one week. Next-generation sequencing was performed to assess microbiota composition, while quantitative real-time PCR was used to measure bacterial concentrations. Additionally, the butyrate concentration in the culture supernatant was assessed as biofilm pathogenicity.
RESULTS: PBE and BC treatments reduced the relative abundance of periodontal pathogenic bacteria, including P. gingivalis, and significantly increased the relative abundance of the genus Streptococcus and nitrate-reducing bacteria, including the genera of Neisseria and Haemophilus. Moreover, the treatment groups exhibited significantly decreased butyrate concentrations.
CONCLUSIONS: Our findings suggest that PBE and BC could suppress dysbiosis triggered by P. gingivalis in microcosm biofilms in vitro by decreasing the relative abundance and amount of periodontal pathogenic bacteria and enhancing those of nitrate-reducing bacteria that have a high relative abundance in orally healthy individuals. In summary, PBE and BC may contribute to the prevention of periodontal disease through their dysbiosis-suppressive and anti-inflammatory effects.},
}
RevDate: 2025-04-10
Enhancement of the start-up and performance of an upflow anaerobic sludge blanket (UASB) reactor using electrochemically-enriched biofilm.
Enzyme and microbial technology, 188:110651 pii:S0141-0229(25)00071-7 [Epub ahead of print].
A novel approach was developed to accelerate the start-up of a 20-L UASB reactor under mesophilic conditions. Two runs were conducted, where the first run (Run I) was inoculated with anaerobic sludge, and the second run (Run II) was inoculated with the same sludge supplemented with enriched electro-active biofilms collected from the working and counter electrodes of anodic and cathodic bio-electrochemical systems (BESs). Reactors' performance and microbial dynamics were monitored over 41 days. Methane production in Run II exceeded 200 mL-CH4/g-COD within 10 days, compared to 29 days in Run I. Run II achieved 80 % removal of soluble COD after 13 days as compared to 23 days in Run I. Sludge washout in Run II stabilized after 3 days, achieving 70 % VSS removal, whereas Run I required 17 days. Greater extracellular polymeric substance (EPS) values and higher protein-to-polysaccharide ratios in Run II may indicate accelerated granules formation mediated by EPS. 16S rRNA gene sequencing analysis results revealed shared genera between both runs but different relative abundances. Methanothrix dominated in Run I, while other archaeal genera, mainly Methanosarcina and Methanobacterium increased in abundance in the Run II. The Enterobacteriaceae family was prevalent in both reactors, with three genera, Citrobacter, Klebsiella, and Enterobacter distinctly dominating at different time points, suggesting potential links with the initial seed sludge or enriched biofilm consortia. The addition of electrochemically grown biofilm in Run II likely enhanced the microbial diversity, contributed to the rapid development of granular syntrophic communities, and improved reactor performance.
Additional Links: PMID-40209633
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@article {pmid40209633,
year = {2025},
author = {Abdallah, M and Greige, S and Webster, CF and Harb, M and Beyenal, H and Wazne, M},
title = {Enhancement of the start-up and performance of an upflow anaerobic sludge blanket (UASB) reactor using electrochemically-enriched biofilm.},
journal = {Enzyme and microbial technology},
volume = {188},
number = {},
pages = {110651},
doi = {10.1016/j.enzmictec.2025.110651},
pmid = {40209633},
issn = {1879-0909},
abstract = {A novel approach was developed to accelerate the start-up of a 20-L UASB reactor under mesophilic conditions. Two runs were conducted, where the first run (Run I) was inoculated with anaerobic sludge, and the second run (Run II) was inoculated with the same sludge supplemented with enriched electro-active biofilms collected from the working and counter electrodes of anodic and cathodic bio-electrochemical systems (BESs). Reactors' performance and microbial dynamics were monitored over 41 days. Methane production in Run II exceeded 200 mL-CH4/g-COD within 10 days, compared to 29 days in Run I. Run II achieved 80 % removal of soluble COD after 13 days as compared to 23 days in Run I. Sludge washout in Run II stabilized after 3 days, achieving 70 % VSS removal, whereas Run I required 17 days. Greater extracellular polymeric substance (EPS) values and higher protein-to-polysaccharide ratios in Run II may indicate accelerated granules formation mediated by EPS. 16S rRNA gene sequencing analysis results revealed shared genera between both runs but different relative abundances. Methanothrix dominated in Run I, while other archaeal genera, mainly Methanosarcina and Methanobacterium increased in abundance in the Run II. The Enterobacteriaceae family was prevalent in both reactors, with three genera, Citrobacter, Klebsiella, and Enterobacter distinctly dominating at different time points, suggesting potential links with the initial seed sludge or enriched biofilm consortia. The addition of electrochemically grown biofilm in Run II likely enhanced the microbial diversity, contributed to the rapid development of granular syntrophic communities, and improved reactor performance.},
}
RevDate: 2025-04-10
CmpDate: 2025-04-10
Antimicrobial applications of inorganic radiosensitizers and their potential in biofilm control.
World journal of microbiology & biotechnology, 41(4):130.
Biofilms are structured microbial communities embedded in a self-produced extracellular matrix. This lifestyle provides significant protection against environmental stressors such as desiccation, chemical treatments and even ionizing radiation. Radiation, while a well-established antibacterial strategy, can be less effective in biofilms. Biofilm superior resilience is due to several advantages such as the shielding provided by the matrix, the metabolic heterogeneity and adaptive stress responses of biofilm-associated cells. To address this challenge, researchers are increasingly employing combination strategies in antibiofilm treatment. Radiosensitizers, compounds originally developed to enhance the efficacy of radiation therapy in cancer treatment, have also garnered attention for their potential in antimicrobial applications. These compounds act by amplifying the effects of radiation, often through mechanisms such as increased oxidative stress or inhibition of DNA repair pathways. However, research on radiosensitizers in bacterial systems has focused on planktonic cultures, with limited studies exploring their effects on biofilms. Given the complexity and unique characteristics of biofilms, their response to radiosensitization remains poorly understood and requires further investigation. The use of radiosensitizers in conjunction with radiation presents a promising approach to overcome the inherent resilience of biofilms. By enhancing the susceptibility of biofilm-associated bacteria to radiation and simultaneously disrupting their protective structures, such approaches could lead to more effective and comprehensive solutions. Understanding the nuanced responses of biofilms to these combined treatments is essential for advancing both medical and environmental applications and addressing the challenge of biofilm persistence.
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@article {pmid40208389,
year = {2025},
author = {Abdeljelil, N and Chatti, A and Gillan, D and Van Houdt, R},
title = {Antimicrobial applications of inorganic radiosensitizers and their potential in biofilm control.},
journal = {World journal of microbiology & biotechnology},
volume = {41},
number = {4},
pages = {130},
pmid = {40208389},
issn = {1573-0972},
mesh = {*Biofilms/drug effects/radiation effects ; *Radiation-Sensitizing Agents/pharmacology ; *Bacteria/drug effects/radiation effects ; *Anti-Bacterial Agents/pharmacology ; *Anti-Infective Agents/pharmacology ; Bacterial Physiological Phenomena/drug effects/radiation effects ; Humans ; },
abstract = {Biofilms are structured microbial communities embedded in a self-produced extracellular matrix. This lifestyle provides significant protection against environmental stressors such as desiccation, chemical treatments and even ionizing radiation. Radiation, while a well-established antibacterial strategy, can be less effective in biofilms. Biofilm superior resilience is due to several advantages such as the shielding provided by the matrix, the metabolic heterogeneity and adaptive stress responses of biofilm-associated cells. To address this challenge, researchers are increasingly employing combination strategies in antibiofilm treatment. Radiosensitizers, compounds originally developed to enhance the efficacy of radiation therapy in cancer treatment, have also garnered attention for their potential in antimicrobial applications. These compounds act by amplifying the effects of radiation, often through mechanisms such as increased oxidative stress or inhibition of DNA repair pathways. However, research on radiosensitizers in bacterial systems has focused on planktonic cultures, with limited studies exploring their effects on biofilms. Given the complexity and unique characteristics of biofilms, their response to radiosensitization remains poorly understood and requires further investigation. The use of radiosensitizers in conjunction with radiation presents a promising approach to overcome the inherent resilience of biofilms. By enhancing the susceptibility of biofilm-associated bacteria to radiation and simultaneously disrupting their protective structures, such approaches could lead to more effective and comprehensive solutions. Understanding the nuanced responses of biofilms to these combined treatments is essential for advancing both medical and environmental applications and addressing the challenge of biofilm persistence.},
}
MeSH Terms:
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*Biofilms/drug effects/radiation effects
*Radiation-Sensitizing Agents/pharmacology
*Bacteria/drug effects/radiation effects
*Anti-Bacterial Agents/pharmacology
*Anti-Infective Agents/pharmacology
Bacterial Physiological Phenomena/drug effects/radiation effects
Humans
RevDate: 2025-04-10
Comprehensive genomic and evolutionary analysis of biofilm matrix clusters and proteins in the Vibrio genus.
mSystems [Epub ahead of print].
UNLABELLED: Vibrio cholerae pathogens cause cholera, an acute diarrheal disease resulting in significant morbidity and mortality worldwide. Biofilms in vibrios enhance their survival in natural ecosystems and facilitate transmission during cholera outbreaks. Critical components of the biofilm matrix include the Vibrio polysaccharides produced by the vps-1 and vps-2 gene clusters and the biofilm matrix proteins encoded in the rbm gene cluster, together comprising the biofilm matrix cluster. However, the biofilm matrix clusters and their evolutionary patterns in other Vibrio species remain underexplored. In this study, we systematically investigated the distribution, diversity, and evolution of biofilm matrix clusters and proteins across the Vibrio genus. Our findings reveal that these gene clusters are sporadically distributed throughout the genus, even appearing in species phylogenetically distant from Vibrio cholerae. Evolutionary analysis of the major biofilm matrix proteins RbmC and Bap1 shows that they are structurally and sequentially related, having undergone structural domain and modular alterations. Additionally, a novel loop-less Bap1 variant was identified, predominantly represented in two phylogenetically distant V. cholerae subspecies clades that share specific gene groups associated with the presence or absence of the protein. Furthermore, our analysis revealed that rbmB, a gene involved in biofilm dispersal, shares a recent common ancestor with Vibriophage tail proteins, suggesting that phages may mimic host functions to evade biofilm-associated defenses. Our study offers a foundational understanding of the diversity and evolution of biofilm matrix clusters in vibrios, laying the groundwork for future biofilm engineering through genetic modification.
IMPORTANCE: Biofilms help vibrios survive in nature and spread cholera. However, the genes that control biofilm formation in vibrios other than Vibrio cholerae are not well understood. In this study, we analyzed the biofilm matrix gene clusters and proteins across diverse Vibrio species to explore their patterns and evolution. We discovered that these genes are spread across different Vibrio species, including those not closely related to V. cholerae. We also found various forms of key biofilm proteins with different structures. Additionally, we identified genes involved in biofilm dispersal that are related to vibriophage genes, highlighting the role of phages in biofilm development. This study not only provides a foundational understanding of biofilm diversity and evolution in vibrios but also leads to new strategies for engineering biofilms through genetic modification, which is crucial for managing cholera outbreaks and improving the environmental resilience of these bacteria.
Additional Links: PMID-40207939
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@article {pmid40207939,
year = {2025},
author = {Yang, Y and Yan, J and Olson, R and Jiang, X},
title = {Comprehensive genomic and evolutionary analysis of biofilm matrix clusters and proteins in the Vibrio genus.},
journal = {mSystems},
volume = {},
number = {},
pages = {e0006025},
doi = {10.1128/msystems.00060-25},
pmid = {40207939},
issn = {2379-5077},
abstract = {UNLABELLED: Vibrio cholerae pathogens cause cholera, an acute diarrheal disease resulting in significant morbidity and mortality worldwide. Biofilms in vibrios enhance their survival in natural ecosystems and facilitate transmission during cholera outbreaks. Critical components of the biofilm matrix include the Vibrio polysaccharides produced by the vps-1 and vps-2 gene clusters and the biofilm matrix proteins encoded in the rbm gene cluster, together comprising the biofilm matrix cluster. However, the biofilm matrix clusters and their evolutionary patterns in other Vibrio species remain underexplored. In this study, we systematically investigated the distribution, diversity, and evolution of biofilm matrix clusters and proteins across the Vibrio genus. Our findings reveal that these gene clusters are sporadically distributed throughout the genus, even appearing in species phylogenetically distant from Vibrio cholerae. Evolutionary analysis of the major biofilm matrix proteins RbmC and Bap1 shows that they are structurally and sequentially related, having undergone structural domain and modular alterations. Additionally, a novel loop-less Bap1 variant was identified, predominantly represented in two phylogenetically distant V. cholerae subspecies clades that share specific gene groups associated with the presence or absence of the protein. Furthermore, our analysis revealed that rbmB, a gene involved in biofilm dispersal, shares a recent common ancestor with Vibriophage tail proteins, suggesting that phages may mimic host functions to evade biofilm-associated defenses. Our study offers a foundational understanding of the diversity and evolution of biofilm matrix clusters in vibrios, laying the groundwork for future biofilm engineering through genetic modification.
IMPORTANCE: Biofilms help vibrios survive in nature and spread cholera. However, the genes that control biofilm formation in vibrios other than Vibrio cholerae are not well understood. In this study, we analyzed the biofilm matrix gene clusters and proteins across diverse Vibrio species to explore their patterns and evolution. We discovered that these genes are spread across different Vibrio species, including those not closely related to V. cholerae. We also found various forms of key biofilm proteins with different structures. Additionally, we identified genes involved in biofilm dispersal that are related to vibriophage genes, highlighting the role of phages in biofilm development. This study not only provides a foundational understanding of biofilm diversity and evolution in vibrios but also leads to new strategies for engineering biofilms through genetic modification, which is crucial for managing cholera outbreaks and improving the environmental resilience of these bacteria.},
}
RevDate: 2025-04-10
CmpDate: 2025-04-10
Surface Texture of Macroplastic Pollution in Streams Alters the Physical Structure and Diversity of Biofilm Communities.
Environmental microbiology reports, 17(2):e70068.
Biofilms can develop on nearly any surface, and in aquatic ecosystems they are essential components of biogeochemical cycles and food webs. Plastic waste in waterways is a new type of surface for biofilm colonisation. To analyse the influence of plastic pollution on the development and diversity of microbial freshwater biofilms that colonised them, we incubated 388 cm[2] veneers of high-density polyethylene (HDPE) with two veneer textures, smooth and rough, and tulip tree wood (Liriodendron tulipifera), in three rural headwater streams at the Savannah River Site (Aiken, SC, USA). We collected biofilms from veneers after 14, 28 and 56 days of incubation and analysed 16S rRNA genes and biofilm properties. We found that plastic negatively affected species richness of biofilms compared with wood, but that evenness was greatest on rough textured HDPE. Beta diversity was primarily influenced by stream site. Beta diversity differed more between wood and plastic veneers than with plastic surface texture and became more different over time. Wood had nine times more biomass than rough HDPE and 40 times more biomass than smooth HDPE. Given the projected increase of macroplastic pollution in aquatic ecosystems, our findings emphasise the need to further understand its effects on biofilm characteristics.
Additional Links: PMID-40205976
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@article {pmid40205976,
year = {2025},
author = {Lopez Avila, F and Capps, KA and Bier, RL},
title = {Surface Texture of Macroplastic Pollution in Streams Alters the Physical Structure and Diversity of Biofilm Communities.},
journal = {Environmental microbiology reports},
volume = {17},
number = {2},
pages = {e70068},
pmid = {40205976},
issn = {1758-2229},
support = {DE-EM0005228//Office of Environmental Management/ ; //University of Georgia River Basin Center John Spencer Research Grant/ ; },
mesh = {*Biofilms/growth & development ; *Rivers/microbiology/chemistry ; *Bacteria/genetics/classification/isolation & purification ; RNA, Ribosomal, 16S/genetics ; Wood/microbiology ; Biodiversity ; *Plastics ; Surface Properties ; Ecosystem ; },
abstract = {Biofilms can develop on nearly any surface, and in aquatic ecosystems they are essential components of biogeochemical cycles and food webs. Plastic waste in waterways is a new type of surface for biofilm colonisation. To analyse the influence of plastic pollution on the development and diversity of microbial freshwater biofilms that colonised them, we incubated 388 cm[2] veneers of high-density polyethylene (HDPE) with two veneer textures, smooth and rough, and tulip tree wood (Liriodendron tulipifera), in three rural headwater streams at the Savannah River Site (Aiken, SC, USA). We collected biofilms from veneers after 14, 28 and 56 days of incubation and analysed 16S rRNA genes and biofilm properties. We found that plastic negatively affected species richness of biofilms compared with wood, but that evenness was greatest on rough textured HDPE. Beta diversity was primarily influenced by stream site. Beta diversity differed more between wood and plastic veneers than with plastic surface texture and became more different over time. Wood had nine times more biomass than rough HDPE and 40 times more biomass than smooth HDPE. Given the projected increase of macroplastic pollution in aquatic ecosystems, our findings emphasise the need to further understand its effects on biofilm characteristics.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Rivers/microbiology/chemistry
*Bacteria/genetics/classification/isolation & purification
RNA, Ribosomal, 16S/genetics
Wood/microbiology
Biodiversity
*Plastics
Surface Properties
Ecosystem
RevDate: 2025-04-11
CmpDate: 2025-04-09
Anti-biofilm and anti-quorum sensing activities of galloylquinic acid against clinical isolates of multidrug-resistant Pseudomonas aeruginosa in open wound infection: in vitro and in vivo efficacy studies.
BMC microbiology, 25(1):206.
BACKGROUND: Pseudomonas aeruginosa can proliferate in immunocompromised individuals, forming biofilms that increase antibiotic resistance. This bacterium poses a significant global health risk due to its resistance to human defenses, antibiotics, and various environmental stresses. The objective of this study was to evaluate the antibacterial, anti-biofilm, and anti-quorum sensing activities of galloylquinic acid compounds (GQAs) extracted from Copaifera lucens leaves against clinical isolates of multidrug-resistant (MDR) P. aeruginosa. We have investigated the optimal concentration of GQAs needed to eradicate preexisting biofilms and manage wound infections caused by P. aeruginosa, in vitro and in vivo.
RESULTS: Our results revealed that GQAs exhibited 25-40 mm inhibition zone diameters, with 1-4 µg/mL MIC and 2-16 µg/mL MBC values. GQAs interfered with the planktonic mode of P. aeruginosa isolates, and significantly inhibited their growth in the pre-formed biofilm architecture, with MBIC80 and MBEC80 values of 64 µg/mL and 128 µg/mL, respectively. The anti-biofilm effect was confirmed by fluorescence staining and confocal microscopy which showed a dramatic reduction in the cell viability and the biofilm thickness (62.5%), after exposure to 128 µg/mL of GQAs in particular. The scanning electron micrographs showed that GQAs impaired biofilm and bacterial structures by interfering with the biomass and the exopolysaccharides forming the matrix. GQAs also interfered with virulence factors and bacterial motility, where 128 µg/mL of GQAs significantly (p < 0.05) reduced rhamnolipid, pyocyanin, and the swarming motility of the organism which play a vital role in the biofilm formation. GQAs downregulated 89% of the quorum-sensing genes (lasI and lasR, pqsA and pqsR) involved in the biofilm formation.
CONCLUSION: GQAs demonstrate significant promise as novel and potent antibiofilm and antivirulence agents against clinical isolates of MDR P. aeruginosa, with substantial potential to enhance wound healing in biofilm-associated infections. This promising antibacterial action positions GQAs as a superior alternative for the treatment of biofilm-associated wound infections, with substantial potential to improve wound healing and mitigate the impact of persistent bacterial infections.
CLINICAL TRIAL NUMBER: not applicable.
Additional Links: PMID-40205343
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Citation:
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@article {pmid40205343,
year = {2025},
author = {Al-Maddboly, LA and El-Salam, MA and Bastos, JK and Hasby, EA and Kushkevych, I and El-Morsi, RM},
title = {Anti-biofilm and anti-quorum sensing activities of galloylquinic acid against clinical isolates of multidrug-resistant Pseudomonas aeruginosa in open wound infection: in vitro and in vivo efficacy studies.},
journal = {BMC microbiology},
volume = {25},
number = {1},
pages = {206},
pmid = {40205343},
issn = {1471-2180},
mesh = {*Biofilms/drug effects/growth & development ; *Pseudomonas aeruginosa/drug effects/physiology/isolation & purification ; *Quorum Sensing/drug effects ; *Wound Infection/microbiology/drug therapy ; *Anti-Bacterial Agents/pharmacology ; Drug Resistance, Multiple, Bacterial/drug effects ; *Pseudomonas Infections/microbiology/drug therapy ; Microbial Sensitivity Tests ; Humans ; Animals ; Plant Leaves/chemistry ; Plant Extracts/pharmacology ; Mice ; },
abstract = {BACKGROUND: Pseudomonas aeruginosa can proliferate in immunocompromised individuals, forming biofilms that increase antibiotic resistance. This bacterium poses a significant global health risk due to its resistance to human defenses, antibiotics, and various environmental stresses. The objective of this study was to evaluate the antibacterial, anti-biofilm, and anti-quorum sensing activities of galloylquinic acid compounds (GQAs) extracted from Copaifera lucens leaves against clinical isolates of multidrug-resistant (MDR) P. aeruginosa. We have investigated the optimal concentration of GQAs needed to eradicate preexisting biofilms and manage wound infections caused by P. aeruginosa, in vitro and in vivo.
RESULTS: Our results revealed that GQAs exhibited 25-40 mm inhibition zone diameters, with 1-4 µg/mL MIC and 2-16 µg/mL MBC values. GQAs interfered with the planktonic mode of P. aeruginosa isolates, and significantly inhibited their growth in the pre-formed biofilm architecture, with MBIC80 and MBEC80 values of 64 µg/mL and 128 µg/mL, respectively. The anti-biofilm effect was confirmed by fluorescence staining and confocal microscopy which showed a dramatic reduction in the cell viability and the biofilm thickness (62.5%), after exposure to 128 µg/mL of GQAs in particular. The scanning electron micrographs showed that GQAs impaired biofilm and bacterial structures by interfering with the biomass and the exopolysaccharides forming the matrix. GQAs also interfered with virulence factors and bacterial motility, where 128 µg/mL of GQAs significantly (p < 0.05) reduced rhamnolipid, pyocyanin, and the swarming motility of the organism which play a vital role in the biofilm formation. GQAs downregulated 89% of the quorum-sensing genes (lasI and lasR, pqsA and pqsR) involved in the biofilm formation.
CONCLUSION: GQAs demonstrate significant promise as novel and potent antibiofilm and antivirulence agents against clinical isolates of MDR P. aeruginosa, with substantial potential to enhance wound healing in biofilm-associated infections. This promising antibacterial action positions GQAs as a superior alternative for the treatment of biofilm-associated wound infections, with substantial potential to improve wound healing and mitigate the impact of persistent bacterial infections.
CLINICAL TRIAL NUMBER: not applicable.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Pseudomonas aeruginosa/drug effects/physiology/isolation & purification
*Quorum Sensing/drug effects
*Wound Infection/microbiology/drug therapy
*Anti-Bacterial Agents/pharmacology
Drug Resistance, Multiple, Bacterial/drug effects
*Pseudomonas Infections/microbiology/drug therapy
Microbial Sensitivity Tests
Humans
Animals
Plant Leaves/chemistry
Plant Extracts/pharmacology
Mice
RevDate: 2025-04-09
Influence of operation sequences on phosphorus ennrichment by polyphosphate accumulating organisms biofilm: performance, phosphorus transfer and phosphate metabolism in biofilm.
Environmental research pii:S0013-9351(25)00811-4 [Epub ahead of print].
This study investigated the impact of different operational sequences on phosphorus removal and enrichment in biofilm phosphorus enrichment system. The research com-pared two distinct operational modes, analyzing phosphorus uptake and release characteristics in cells and extracellular polymeric substances (EPS) over a single cycle, while also examining microbial community composition and associated functional genes. After long-term acclimation, the Ae/An system achieved higher phosphorus concentration (120 mg/L) than the An/Ae system (65 mg/L). However, the An/Ae system showed stronger phosphorus uptake and release capabilities due to higher phosphorus load during the aerobic phase. In both systems, Mg-P and Ca-P dominated in cells and EPS. Compared to the Ae/An system, the An/Ae system stored phosphorus mainly in EPS, with higher orthophosphate content. However, EPS-associated phosphorus is more easily released, explaining the An/Ae system's higher aerobic phosphorus load but lower overall storage capacity. Microbial analysis revealed higher abundance of phosphorus accumulating organisms (PAOs) in the An/Ae system (25.99% vs. 19.69%), while glycogen accumulating organisms (GAOs) showed the opposite trend. Candidatus Competibacter was abundant in both systems and correlated with phosphorus metabolism genes. The An/Ae system expressed the pst system more, whereas the Ae/An favored the pit system, suggesting that transfer system variations affect enrichment solution concentration. Lower expression of polyphosphate kinase (ppk1) in the An/Ae system may explain its unstatisfied phosphorus enrichment performance. Mantel analysis confirmed connections among environmental factors, kinetic parameters, phosphorus metabolism genes, and phosphorus morphology in EPS, demonstrating their combined influence on enrichment solution concentration.
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@article {pmid40203978,
year = {2025},
author = {Song, G and Bi, Z and Liu, Y and Huang, Y},
title = {Influence of operation sequences on phosphorus ennrichment by polyphosphate accumulating organisms biofilm: performance, phosphorus transfer and phosphate metabolism in biofilm.},
journal = {Environmental research},
volume = {},
number = {},
pages = {121560},
doi = {10.1016/j.envres.2025.121560},
pmid = {40203978},
issn = {1096-0953},
abstract = {This study investigated the impact of different operational sequences on phosphorus removal and enrichment in biofilm phosphorus enrichment system. The research com-pared two distinct operational modes, analyzing phosphorus uptake and release characteristics in cells and extracellular polymeric substances (EPS) over a single cycle, while also examining microbial community composition and associated functional genes. After long-term acclimation, the Ae/An system achieved higher phosphorus concentration (120 mg/L) than the An/Ae system (65 mg/L). However, the An/Ae system showed stronger phosphorus uptake and release capabilities due to higher phosphorus load during the aerobic phase. In both systems, Mg-P and Ca-P dominated in cells and EPS. Compared to the Ae/An system, the An/Ae system stored phosphorus mainly in EPS, with higher orthophosphate content. However, EPS-associated phosphorus is more easily released, explaining the An/Ae system's higher aerobic phosphorus load but lower overall storage capacity. Microbial analysis revealed higher abundance of phosphorus accumulating organisms (PAOs) in the An/Ae system (25.99% vs. 19.69%), while glycogen accumulating organisms (GAOs) showed the opposite trend. Candidatus Competibacter was abundant in both systems and correlated with phosphorus metabolism genes. The An/Ae system expressed the pst system more, whereas the Ae/An favored the pit system, suggesting that transfer system variations affect enrichment solution concentration. Lower expression of polyphosphate kinase (ppk1) in the An/Ae system may explain its unstatisfied phosphorus enrichment performance. Mantel analysis confirmed connections among environmental factors, kinetic parameters, phosphorus metabolism genes, and phosphorus morphology in EPS, demonstrating their combined influence on enrichment solution concentration.},
}
RevDate: 2025-04-08
Comparison of the start-up of rotating biofilm contactor reactor with HN-AD bacteria inoculation under high and low influent ammonia conditions.
Journal of environmental management, 381:125206 pii:S0301-4797(25)01182-X [Epub ahead of print].
Biofilm formation is critical for the engineering application of pure biofilm RBC processes inoculated with HN-AD bacteria. This study focused on comparing the startup of pure biofilm RBC systems inoculated with HN-AD bacteria under high ammonia nitrogen (NH4[+]-N = 500 mg/L, H-RBC) and low ammonia nitrogen (NH4[+]-N = 120 mg/L, L-RBC) influent conditions. The results showed that H-RBC shortened the biofilm formation time by 6 days. Additionally, the average removal efficiencies of ammonia nitrogen and TN were 30.70 % and 38.98 % higher than those of L-RBC, respectively. High-throughput sequencing indicated that compared with L-RBC, H-RBC did not significantly change the types of HN-AD bacteria but significantly increased the abundance of the key HN-AD bacterial genera Planktosalinus and Corynebacterium. Functional gene prediction analysis showed that the abundance of key functional genes affecting the nitrogen removal process, nirS and nosZ, in H-RBC was significantly higher than in L-RBC. Phenotypic prediction analysis revealed that H-RBC could better resist changes in the external environment and had stronger nitrogen removal capacity. These findings provide a theoretical basis and effective approach for the start-up of pure biofilm RBC system.
Additional Links: PMID-40199215
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PubMed:
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@article {pmid40199215,
year = {2025},
author = {Qin, S and Lin, Y and Yang, C and Zhang, Q},
title = {Comparison of the start-up of rotating biofilm contactor reactor with HN-AD bacteria inoculation under high and low influent ammonia conditions.},
journal = {Journal of environmental management},
volume = {381},
number = {},
pages = {125206},
doi = {10.1016/j.jenvman.2025.125206},
pmid = {40199215},
issn = {1095-8630},
abstract = {Biofilm formation is critical for the engineering application of pure biofilm RBC processes inoculated with HN-AD bacteria. This study focused on comparing the startup of pure biofilm RBC systems inoculated with HN-AD bacteria under high ammonia nitrogen (NH4[+]-N = 500 mg/L, H-RBC) and low ammonia nitrogen (NH4[+]-N = 120 mg/L, L-RBC) influent conditions. The results showed that H-RBC shortened the biofilm formation time by 6 days. Additionally, the average removal efficiencies of ammonia nitrogen and TN were 30.70 % and 38.98 % higher than those of L-RBC, respectively. High-throughput sequencing indicated that compared with L-RBC, H-RBC did not significantly change the types of HN-AD bacteria but significantly increased the abundance of the key HN-AD bacterial genera Planktosalinus and Corynebacterium. Functional gene prediction analysis showed that the abundance of key functional genes affecting the nitrogen removal process, nirS and nosZ, in H-RBC was significantly higher than in L-RBC. Phenotypic prediction analysis revealed that H-RBC could better resist changes in the external environment and had stronger nitrogen removal capacity. These findings provide a theoretical basis and effective approach for the start-up of pure biofilm RBC system.},
}
RevDate: 2025-04-08
CmpDate: 2025-04-08
Integrating Modified Fe3O4 Nanoparticles and Nisin with T4 Bacteriophage for Enhanced Biofilm Eradication.
Current microbiology, 82(6):237.
Biofilm formation presents significant challenges in healthcare, food processing, and water treatment, contributing to antibiotic resistance and persistent infections. Effective strategies to combat biofilm-associated infections are urgently needed. This study introduces a novel approach to biofilm removal by bio-functionalizing T4 bacteriophage with modified Fe3O4 nanoparticles (NPs) and Nisin, an antibacterial peptide, to form the Fe3O4-Phage-T4 + Nisin complex. The aim is to enhance antimicrobial efficacy and biofilm eradication. The Fe3O4-Phage-T4 + Nisin complex was synthesized by conjugating T4 bacteriophage with modified Fe3O4 NPs and Nisin. The antimicrobial and antibiofilm activity of the complex was evaluated against multidrug-resistant Pseudomonas aeruginosa strains (PA01 and PA14) using biofilm inhibition and eradication assays. Stability and efficacy were further tested across a pH range of 5 to 8. The Fe3O4-Phage-T4 + Nisin complex exhibited superior biofilm removal compared to its individual components. The integration of Nisin broadened the antibacterial spectrum, targeting both Gram-positive and Gram-negative bacteria, while the modified Fe3O4 NPs enhanced phage penetration and bacterial cell disruption. The complex demonstrated significant biofilm inhibition and eradication, addressing the challenge of biofilm-related antibiotic tolerance, which often necessitates high antibiotic doses. Additionally, it maintained stability and efficacy across varying pH conditions.
Additional Links: PMID-40198373
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@article {pmid40198373,
year = {2025},
author = {Zhang, P and Yang, H and Ahmad, MT and Zheng, Q and Nie, G and Ahmad, A and Raza, M and Raza, S},
title = {Integrating Modified Fe3O4 Nanoparticles and Nisin with T4 Bacteriophage for Enhanced Biofilm Eradication.},
journal = {Current microbiology},
volume = {82},
number = {6},
pages = {237},
pmid = {40198373},
issn = {1432-0991},
support = {G2019ZK53//Scientific Research Start-up Project of High Level Talents in Yulin Normal University/ ; 22266017//National Natural Science Foundation of China/ ; JZB2201//Doctoral Scientific Research Start-up Project of Jinggangshan University/ ; AA20302013//Guangxi Innovation Driven Development Major Project/ ; G2019ZK53//Scientific Research Startup Project of High Level Talents in Yulin Normal University/ ; },
mesh = {*Nisin/pharmacology/chemistry ; *Biofilms/drug effects/growth & development ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Bacteriophage T4/chemistry/physiology ; *Pseudomonas aeruginosa/drug effects/physiology/virology ; Microbial Sensitivity Tests ; },
abstract = {Biofilm formation presents significant challenges in healthcare, food processing, and water treatment, contributing to antibiotic resistance and persistent infections. Effective strategies to combat biofilm-associated infections are urgently needed. This study introduces a novel approach to biofilm removal by bio-functionalizing T4 bacteriophage with modified Fe3O4 nanoparticles (NPs) and Nisin, an antibacterial peptide, to form the Fe3O4-Phage-T4 + Nisin complex. The aim is to enhance antimicrobial efficacy and biofilm eradication. The Fe3O4-Phage-T4 + Nisin complex was synthesized by conjugating T4 bacteriophage with modified Fe3O4 NPs and Nisin. The antimicrobial and antibiofilm activity of the complex was evaluated against multidrug-resistant Pseudomonas aeruginosa strains (PA01 and PA14) using biofilm inhibition and eradication assays. Stability and efficacy were further tested across a pH range of 5 to 8. The Fe3O4-Phage-T4 + Nisin complex exhibited superior biofilm removal compared to its individual components. The integration of Nisin broadened the antibacterial spectrum, targeting both Gram-positive and Gram-negative bacteria, while the modified Fe3O4 NPs enhanced phage penetration and bacterial cell disruption. The complex demonstrated significant biofilm inhibition and eradication, addressing the challenge of biofilm-related antibiotic tolerance, which often necessitates high antibiotic doses. Additionally, it maintained stability and efficacy across varying pH conditions.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Nisin/pharmacology/chemistry
*Biofilms/drug effects/growth & development
*Anti-Bacterial Agents/pharmacology/chemistry
*Bacteriophage T4/chemistry/physiology
*Pseudomonas aeruginosa/drug effects/physiology/virology
Microbial Sensitivity Tests
RevDate: 2025-04-08
Small Intestine on a Chip Demonstrates Physiologic Mucus Secretion in the Presence of Lacticaseibacillus rhamnosus Biofilm.
Biotechnology and bioengineering [Epub ahead of print].
The small intestine is an area of the digestive system difficult to access using current medical procedures, which prevents studies on the interactions between food, drugs, the small intestinal epithelium, and resident microbiota. Therefore, there is a need to develop novel microfluidic models that mimic the intestinal biological and mechanical environments. These models can be used for drug discovery and disease modeling and have the potential to reduce reliance on animal models. The goal of this study was to develop a small intestine on a chip with both enterocyte (Caco-2) and goblet (HT29-MTX) cells cocultured with Lacticaseibacillus rhamnosus biofilms, which is of one of several genera present in the small intestinal microbiota. L. rhamnosus was introduced following the establishment of the epithelial barrier. The shear stress within the device was kept in the lower physiological range (0.3 mPa) to enable biofilm development over the in vitro epithelium. The epithelial barrier differentiated after 5 days of dynamic culture with cell polarity and permeability similar to the human small intestine. The presence of biofilms did not alter the barrier's permeability in dynamic conditions. Under fluid flow, the complete model remained viable and functional for more than 5 days, while the static model remained functional for only 1 day. The presence of biofilm increased the secretion of acidic and neutral mucins by the epithelial barrier. Furthermore, the small intestine on a chip also showed increased MUC2 production, which is a dominant gel-forming mucin in the small intestine. This model builds on previous publications as it establishes a stable environment that closely mimics in vivo conditions and can be used to study intestinal physiology, food-intestinal interactions, and drug development.
Additional Links: PMID-40197633
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@article {pmid40197633,
year = {2025},
author = {Dash, SK and Marques, CNH and Mahler, GJ},
title = {Small Intestine on a Chip Demonstrates Physiologic Mucus Secretion in the Presence of Lacticaseibacillus rhamnosus Biofilm.},
journal = {Biotechnology and bioengineering},
volume = {},
number = {},
pages = {},
doi = {10.1002/bit.28989},
pmid = {40197633},
issn = {1097-0290},
support = {//This work was funded by National Institutes of Health (R01ES028788)./ ; },
abstract = {The small intestine is an area of the digestive system difficult to access using current medical procedures, which prevents studies on the interactions between food, drugs, the small intestinal epithelium, and resident microbiota. Therefore, there is a need to develop novel microfluidic models that mimic the intestinal biological and mechanical environments. These models can be used for drug discovery and disease modeling and have the potential to reduce reliance on animal models. The goal of this study was to develop a small intestine on a chip with both enterocyte (Caco-2) and goblet (HT29-MTX) cells cocultured with Lacticaseibacillus rhamnosus biofilms, which is of one of several genera present in the small intestinal microbiota. L. rhamnosus was introduced following the establishment of the epithelial barrier. The shear stress within the device was kept in the lower physiological range (0.3 mPa) to enable biofilm development over the in vitro epithelium. The epithelial barrier differentiated after 5 days of dynamic culture with cell polarity and permeability similar to the human small intestine. The presence of biofilms did not alter the barrier's permeability in dynamic conditions. Under fluid flow, the complete model remained viable and functional for more than 5 days, while the static model remained functional for only 1 day. The presence of biofilm increased the secretion of acidic and neutral mucins by the epithelial barrier. Furthermore, the small intestine on a chip also showed increased MUC2 production, which is a dominant gel-forming mucin in the small intestine. This model builds on previous publications as it establishes a stable environment that closely mimics in vivo conditions and can be used to study intestinal physiology, food-intestinal interactions, and drug development.},
}
RevDate: 2025-04-10
CmpDate: 2025-04-07
Dry Surface Biofilm Formation by Candida auris Facilitates Persistence and Tolerance to Sodium Hypochlorite.
APMIS : acta pathologica, microbiologica, et immunologica Scandinavica, 133(4):e70022.
Candida auris is an enigmatic fungal pathogen, recently elevated as a critical priority group pathogen by the World Health Organisation, linked with its ability to cause outbreaks within nosocomial care units, facilitated through environmental persistence. We investigated the susceptibility of phenotypically distinct C. auris isolates to sodium hypochlorite (NaOCl), and evaluated the role of biofilms in surviving disinfection using a dry-surface biofilm (DSB) model and transcriptomic profiling. Planktonic cells were tested for susceptibility to NaOCl, with biofilm formation using the 12-day DSB model, assessed using viable counts, biomass assays and microscopy. Disinfection efficacy was assessed using clinical protocols of 500-1,000 ppm for 1-5 min. RNA sequencing was performed on untreated DSBs in comparison to planktonic cells. Isolates were found to be susceptible planktonically, but grew NaOCl-tolerant biofilms, with only 2-4 log10 reductions in viable cells observed at highest concentrations. Transcriptomics identified DSB upregulation of ABC transporters and iron acquisition pathways relative to planktonic cells. Our findings optimized a DSB protocol in which C. auris can mediate tolerance to NaOCl disinfection, suggesting a lifestyle through which this problematic yeast can environmentally persist. Mechanistically, it has been shown for the first time that upregulation of small-molecule and iron transport pathways are potential facilitators of environmental survival.
Additional Links: PMID-40194790
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@article {pmid40194790,
year = {2025},
author = {Ware, A and Johnston, W and Delaney, C and Butcher, MC and Ramage, G and Price, L and Butcher, J and Kean, R},
title = {Dry Surface Biofilm Formation by Candida auris Facilitates Persistence and Tolerance to Sodium Hypochlorite.},
journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica},
volume = {133},
number = {4},
pages = {e70022},
pmid = {40194790},
issn = {1600-0463},
mesh = {*Biofilms/drug effects/growth & development ; *Sodium Hypochlorite/pharmacology ; *Candida auris/drug effects/physiology/genetics ; *Disinfectants/pharmacology ; Gene Expression Profiling ; Humans ; Transcriptome ; Microbial Viability/drug effects ; Disinfection ; },
abstract = {Candida auris is an enigmatic fungal pathogen, recently elevated as a critical priority group pathogen by the World Health Organisation, linked with its ability to cause outbreaks within nosocomial care units, facilitated through environmental persistence. We investigated the susceptibility of phenotypically distinct C. auris isolates to sodium hypochlorite (NaOCl), and evaluated the role of biofilms in surviving disinfection using a dry-surface biofilm (DSB) model and transcriptomic profiling. Planktonic cells were tested for susceptibility to NaOCl, with biofilm formation using the 12-day DSB model, assessed using viable counts, biomass assays and microscopy. Disinfection efficacy was assessed using clinical protocols of 500-1,000 ppm for 1-5 min. RNA sequencing was performed on untreated DSBs in comparison to planktonic cells. Isolates were found to be susceptible planktonically, but grew NaOCl-tolerant biofilms, with only 2-4 log10 reductions in viable cells observed at highest concentrations. Transcriptomics identified DSB upregulation of ABC transporters and iron acquisition pathways relative to planktonic cells. Our findings optimized a DSB protocol in which C. auris can mediate tolerance to NaOCl disinfection, suggesting a lifestyle through which this problematic yeast can environmentally persist. Mechanistically, it has been shown for the first time that upregulation of small-molecule and iron transport pathways are potential facilitators of environmental survival.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Sodium Hypochlorite/pharmacology
*Candida auris/drug effects/physiology/genetics
*Disinfectants/pharmacology
Gene Expression Profiling
Humans
Transcriptome
Microbial Viability/drug effects
Disinfection
RevDate: 2025-04-07
Closed fixed-bed bacteria-algae biofilm reactor: A promising solution for phenol containing wastewater treatment and resource transformation.
Journal of hazardous materials, 492:138176 pii:S0304-3894(25)01091-X [Epub ahead of print].
This study focuses on treating phenolic wastewater with a novel closed fixed-bed bacteria-algae biofilm reactor (CF-BABR) to enhance resource transformation for phenolic substances. The CF-BABR showed strong impact - load resistance and stable degradation efficiency, fully degrading phenolic compounds at concentrations from 0 to 150 mg/L. From the inflow to the outflow, the effective sequences, abundance, and diversity of bacteria decreased. Chlorobaculum was the dominant bacterium for phenolic pollutant degradation. The abundance of fungi decreased gradually, while their diversity increased. Kalenjinia and Cutaneotrichosporon played a synergistic role in reducing pollutant toxicity. The high - concentration pollutants at the influent led to a higher abundance of microalgal communities, and Scenedesmaceae became the most dominant algal family, which was positively correlated with the degradation of phenolic compounds. Functional gene prediction indicated that the abundance of functional genes in bacteria decreased overall along the wastewater flow. Carbohydrate metabolism and amino acid metabolism were the most active secondary pathways. In fungi, the predicted gene functions had the highest abundance in the upstream region. Metabolic intermediates such as organic acids and derivatives, lipids and lipid - like molecules, and carboxylic acids and derivatives demonstrated the degradation effect of CF-BABR on phenolic compounds.
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@article {pmid40194331,
year = {2025},
author = {Yang, Y and Li, S and Zhou, X and Zhu, M and Zhou, W and Shi, J},
title = {Closed fixed-bed bacteria-algae biofilm reactor: A promising solution for phenol containing wastewater treatment and resource transformation.},
journal = {Journal of hazardous materials},
volume = {492},
number = {},
pages = {138176},
doi = {10.1016/j.jhazmat.2025.138176},
pmid = {40194331},
issn = {1873-3336},
abstract = {This study focuses on treating phenolic wastewater with a novel closed fixed-bed bacteria-algae biofilm reactor (CF-BABR) to enhance resource transformation for phenolic substances. The CF-BABR showed strong impact - load resistance and stable degradation efficiency, fully degrading phenolic compounds at concentrations from 0 to 150 mg/L. From the inflow to the outflow, the effective sequences, abundance, and diversity of bacteria decreased. Chlorobaculum was the dominant bacterium for phenolic pollutant degradation. The abundance of fungi decreased gradually, while their diversity increased. Kalenjinia and Cutaneotrichosporon played a synergistic role in reducing pollutant toxicity. The high - concentration pollutants at the influent led to a higher abundance of microalgal communities, and Scenedesmaceae became the most dominant algal family, which was positively correlated with the degradation of phenolic compounds. Functional gene prediction indicated that the abundance of functional genes in bacteria decreased overall along the wastewater flow. Carbohydrate metabolism and amino acid metabolism were the most active secondary pathways. In fungi, the predicted gene functions had the highest abundance in the upstream region. Metabolic intermediates such as organic acids and derivatives, lipids and lipid - like molecules, and carboxylic acids and derivatives demonstrated the degradation effect of CF-BABR on phenolic compounds.},
}
RevDate: 2025-04-07
Comprehensive Bioactivities and Phytochemical Profiling of Rumex vesicarius: Antioxidant Potential, Anti-Diabetic Properties, and Anti-Biofilm Effects under Thermal Treatment.
Chemistry & biodiversity [Epub ahead of print].
This study investigates the effect of thermal treatment on the phytochemical composition and bioactivities of Rumex vesicarius, focusing on its antioxidant, antidiabetic, and anti-biofilm properties. Quantitative analysis showed that at ambient temperature, the extract had the highest phenolics (57.89 mg GAE/g), flavonoids (19.45 mg QE/g), tannins (12.78 mg CE/g), flavonols (6.48 mg), and anthraquinones (2.078 mg). At 60°C, it retained significant phenolics (52.89 mg GAE/g) and flavonoids (18.45 mg QE/g) with minimal degradation. At 90°C, phenolics decreased slightly (43.59 mg GAE/g), but enzymatic inhibition and antimicrobial properties improved. β-Carotene stability varied, with untreated extract at IC50 of 118.136 µg/mL. Peak antioxidant activity was at 150°C (IC50 = 102.77 µg/mL), with degradation above 150°C. Antidiabetic potential, via α-amylase and α-glucosidase inhibition, showed lowest IC50 values (92.106 µg/mL for both) at 90°C. Beyond 120°C, IC50 rose to 268.35 µg/mL (α-amylase) and 268.31 µg/mL (α-glucosidase) at 210°C. Anti-biofilm activity peaked at 90°C (IC50 = 33.55 µg/mL), with untreated and 60°C extracts showing strong inhibition (~80-90%). Above 90°C, inhibition dropped, reaching IC50 of 253.53 µg/mL at 210°C. Moderate heating (60°C-90°C) optimizes bioactive availability, positioning R. vesicarius for pharmaceutical and nutraceutical applications.
Additional Links: PMID-40193246
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PubMed:
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@article {pmid40193246,
year = {2025},
author = {Bouafia, A and Laib, I and Laouini, SE and Azzi, M and Alharthi, F and Al Souwaileh, A and Abdullah, JAA},
title = {Comprehensive Bioactivities and Phytochemical Profiling of Rumex vesicarius: Antioxidant Potential, Anti-Diabetic Properties, and Anti-Biofilm Effects under Thermal Treatment.},
journal = {Chemistry & biodiversity},
volume = {},
number = {},
pages = {e202500329},
doi = {10.1002/cbdv.202500329},
pmid = {40193246},
issn = {1612-1880},
abstract = {This study investigates the effect of thermal treatment on the phytochemical composition and bioactivities of Rumex vesicarius, focusing on its antioxidant, antidiabetic, and anti-biofilm properties. Quantitative analysis showed that at ambient temperature, the extract had the highest phenolics (57.89 mg GAE/g), flavonoids (19.45 mg QE/g), tannins (12.78 mg CE/g), flavonols (6.48 mg), and anthraquinones (2.078 mg). At 60°C, it retained significant phenolics (52.89 mg GAE/g) and flavonoids (18.45 mg QE/g) with minimal degradation. At 90°C, phenolics decreased slightly (43.59 mg GAE/g), but enzymatic inhibition and antimicrobial properties improved. β-Carotene stability varied, with untreated extract at IC50 of 118.136 µg/mL. Peak antioxidant activity was at 150°C (IC50 = 102.77 µg/mL), with degradation above 150°C. Antidiabetic potential, via α-amylase and α-glucosidase inhibition, showed lowest IC50 values (92.106 µg/mL for both) at 90°C. Beyond 120°C, IC50 rose to 268.35 µg/mL (α-amylase) and 268.31 µg/mL (α-glucosidase) at 210°C. Anti-biofilm activity peaked at 90°C (IC50 = 33.55 µg/mL), with untreated and 60°C extracts showing strong inhibition (~80-90%). Above 90°C, inhibition dropped, reaching IC50 of 253.53 µg/mL at 210°C. Moderate heating (60°C-90°C) optimizes bioactive availability, positioning R. vesicarius for pharmaceutical and nutraceutical applications.},
}
RevDate: 2025-04-07
Harnessing Biofilm Scaffold for Structurally Adaptative Slippery Surfaces with Integrated Antifouling and Anti-Corrosion Properties.
Angewandte Chemie (International ed. in English) [Epub ahead of print].
Artificial liquid-repellent surfaces are highly desirable to combat pervasive biofouling and corrosion in biological environments. However, existing strategies often suffer from slow binding kinetics and harsh fabrication conditions, hindering the concurrent integration of liquid repellency, universal adhesion, and robust flexibility. Herein, we report that it is possible to engineer microbial biofilms as eco-friendly, cohesive, and flexible materials for omniphobic slippery coatings fulfilling all these requirements. Unlike conventional synthetic slippery coatings requiring laborious surface pretreatments, biofilm sheets formed on demand assemble a durable nanotextured framework on diverse substrates with multiple material categories and surface topologies, serving as hydrophobic lubricant reservoirs. Employing this renewable material enables the scalable and sustainable coating production. The resulting optically transparent and highly flexible coatings manifest exceptional self-cleaning properties, readily shedding both waterborne and oily liquids over a broad viscosity range. Notably, the synergy between the corrosion-protective extracellular matrix and non-stick slipping motion confers unprecedented anti-biofouling efficacy and corrosion resistance. This study offers a distinctive perspective on harnessing ubiquitous native biofilms as biomaterials for self-adaptive coatings, facilitating tailored functionality across broad applications.
Additional Links: PMID-40192598
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PubMed:
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@article {pmid40192598,
year = {2025},
author = {Li, X and Zhang, R and Zhang, J and Li, Q and Yu, Z and Zhou, Z and Lin, S and Li, Z and Cui, M and Zhao, W and Wang, L and Wang, F and Xu, D},
title = {Harnessing Biofilm Scaffold for Structurally Adaptative Slippery Surfaces with Integrated Antifouling and Anti-Corrosion Properties.},
journal = {Angewandte Chemie (International ed. in English)},
volume = {},
number = {},
pages = {e202503295},
doi = {10.1002/anie.202503295},
pmid = {40192598},
issn = {1521-3773},
abstract = {Artificial liquid-repellent surfaces are highly desirable to combat pervasive biofouling and corrosion in biological environments. However, existing strategies often suffer from slow binding kinetics and harsh fabrication conditions, hindering the concurrent integration of liquid repellency, universal adhesion, and robust flexibility. Herein, we report that it is possible to engineer microbial biofilms as eco-friendly, cohesive, and flexible materials for omniphobic slippery coatings fulfilling all these requirements. Unlike conventional synthetic slippery coatings requiring laborious surface pretreatments, biofilm sheets formed on demand assemble a durable nanotextured framework on diverse substrates with multiple material categories and surface topologies, serving as hydrophobic lubricant reservoirs. Employing this renewable material enables the scalable and sustainable coating production. The resulting optically transparent and highly flexible coatings manifest exceptional self-cleaning properties, readily shedding both waterborne and oily liquids over a broad viscosity range. Notably, the synergy between the corrosion-protective extracellular matrix and non-stick slipping motion confers unprecedented anti-biofouling efficacy and corrosion resistance. This study offers a distinctive perspective on harnessing ubiquitous native biofilms as biomaterials for self-adaptive coatings, facilitating tailored functionality across broad applications.},
}
RevDate: 2025-04-08
Site-specific incubations reveal biofilm diversity and functional adaptations in deep, ancient desert aquifers.
Frontiers in microbiology, 16:1533115.
Deep pristine aquifers are ecological hotspots with diverse microbial life, where microorganisms exist either attached (sessile) to solid substrates or suspended in groundwater (planktonic). Characterizing the attached microbial communities is of paramount importance, especially in the context of biofouling. However, obtaining samples of attached microbes that thrive under natural (undisturbed) conditions is challenging. Our study addresses this by retrieving sessile microbes on-site. We installed columns filled with site-specific rock cuttings at the wellhead, allowing fresh groundwater to flow continuously for approximately 60 days. We hypothesized that the attached microbial communities would differ structurally from planktonic microbes due to the aquifer's lithological and mineralogical composition. This study involved an exploratory examination of the microbial communities in different aquifers with distinct mineralogies, including quartzitic sandstone, calcareous, chert, and highly heterogeneous (clastic) aquifers in Israel's Negev Desert. Metagenomic analysis revealed both shared and distinct microbial communities among attached and planktonic forms in the various environments, likely shaped by the aquifers' physical, lithological, and mineralogical properties. A wealth of carbon-fixation pathways and energy-conservation strategies in the attached microbiome provide evidence for the potential productivity of these biofilms. We identified widespread genetic potential for biofilm formation (e.g., via pili, flagella, and extracellular polymeric substance production) and the interactome (e.g., quorum-sensing genes). Our assessment of these functions provides a genomic framework for groundwater management and biofouling treatment.
Additional Links: PMID-40190731
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Citation:
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@article {pmid40190731,
year = {2025},
author = {Atencio, B and Malavin, S and Rubin-Blum, M and Ram, R and Adar, E and Ronen, Z},
title = {Site-specific incubations reveal biofilm diversity and functional adaptations in deep, ancient desert aquifers.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1533115},
pmid = {40190731},
issn = {1664-302X},
abstract = {Deep pristine aquifers are ecological hotspots with diverse microbial life, where microorganisms exist either attached (sessile) to solid substrates or suspended in groundwater (planktonic). Characterizing the attached microbial communities is of paramount importance, especially in the context of biofouling. However, obtaining samples of attached microbes that thrive under natural (undisturbed) conditions is challenging. Our study addresses this by retrieving sessile microbes on-site. We installed columns filled with site-specific rock cuttings at the wellhead, allowing fresh groundwater to flow continuously for approximately 60 days. We hypothesized that the attached microbial communities would differ structurally from planktonic microbes due to the aquifer's lithological and mineralogical composition. This study involved an exploratory examination of the microbial communities in different aquifers with distinct mineralogies, including quartzitic sandstone, calcareous, chert, and highly heterogeneous (clastic) aquifers in Israel's Negev Desert. Metagenomic analysis revealed both shared and distinct microbial communities among attached and planktonic forms in the various environments, likely shaped by the aquifers' physical, lithological, and mineralogical properties. A wealth of carbon-fixation pathways and energy-conservation strategies in the attached microbiome provide evidence for the potential productivity of these biofilms. We identified widespread genetic potential for biofilm formation (e.g., via pili, flagella, and extracellular polymeric substance production) and the interactome (e.g., quorum-sensing genes). Our assessment of these functions provides a genomic framework for groundwater management and biofouling treatment.},
}
RevDate: 2025-04-06
CmpDate: 2025-04-06
Bioactive Fraction of Streptomyces thinghirensis MSA1 Effectively Inhibits Biofilm Forming Clinically Significant AMR Pathogens.
Current microbiology, 82(6):234.
The escalating threat of antibiotic-resistant microorganisms necessitate the discovery of novel antibacterial agents. This study explores the potential of marine-associated actinomycetes, focusing on Streptomyces thinghirensis MSA1, isolated from the marine sponge Callyspongia diffusa in Palk Bay, India, for its notable antibacterial properties. To optimize the production of bioactive compounds of S. thinghirensis MSA1, we established optimal growth conditions (30 °C, pH 7, 2% salinity, 9-day incubation) and utilized ISP4 medium for enhanced secondary metabolite production. The extracted compound, MSA1, was analyzed through FTIR and GCMS, identifying 20 biologically active components. MSA1 demonstrated potent antibacterial activity against significant pathogens, including Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa, and MRSA, alongside remarkable antioxidant and anti-biofilm properties. These findings highlight the potential of MSA1 as a promising candidate for developing treatments against antibiotic-resistant infections. This study acknowledges the preliminary nature of the findings and the necessity for further in vivo and clinical trials to fully ascertain the therapeutic potential of MSA1. This research opens avenues for novel antibacterial agents in the fight against antibiotic resistance, underscoring the value of marine biodiversity in medical science.
Additional Links: PMID-40188414
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@article {pmid40188414,
year = {2025},
author = {Fathima, SA and Arafath, AY and Prathiviraj, R and Hassan, S and Kiran, GS and Selvin, J},
title = {Bioactive Fraction of Streptomyces thinghirensis MSA1 Effectively Inhibits Biofilm Forming Clinically Significant AMR Pathogens.},
journal = {Current microbiology},
volume = {82},
number = {6},
pages = {234},
pmid = {40188414},
issn = {1432-0991},
mesh = {*Streptomyces/chemistry/metabolism/isolation & purification ; *Anti-Bacterial Agents/pharmacology/chemistry/isolation & purification ; *Biofilms/drug effects/growth & development ; Microbial Sensitivity Tests ; Animals ; Porifera/microbiology ; India ; *Bacteria/drug effects ; Escherichia coli/drug effects ; Klebsiella pneumoniae/drug effects ; },
abstract = {The escalating threat of antibiotic-resistant microorganisms necessitate the discovery of novel antibacterial agents. This study explores the potential of marine-associated actinomycetes, focusing on Streptomyces thinghirensis MSA1, isolated from the marine sponge Callyspongia diffusa in Palk Bay, India, for its notable antibacterial properties. To optimize the production of bioactive compounds of S. thinghirensis MSA1, we established optimal growth conditions (30 °C, pH 7, 2% salinity, 9-day incubation) and utilized ISP4 medium for enhanced secondary metabolite production. The extracted compound, MSA1, was analyzed through FTIR and GCMS, identifying 20 biologically active components. MSA1 demonstrated potent antibacterial activity against significant pathogens, including Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa, and MRSA, alongside remarkable antioxidant and anti-biofilm properties. These findings highlight the potential of MSA1 as a promising candidate for developing treatments against antibiotic-resistant infections. This study acknowledges the preliminary nature of the findings and the necessity for further in vivo and clinical trials to fully ascertain the therapeutic potential of MSA1. This research opens avenues for novel antibacterial agents in the fight against antibiotic resistance, underscoring the value of marine biodiversity in medical science.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Streptomyces/chemistry/metabolism/isolation & purification
*Anti-Bacterial Agents/pharmacology/chemistry/isolation & purification
*Biofilms/drug effects/growth & development
Microbial Sensitivity Tests
Animals
Porifera/microbiology
India
*Bacteria/drug effects
Escherichia coli/drug effects
Klebsiella pneumoniae/drug effects
RevDate: 2025-04-05
Synthesis and antimicrobial evaluation of novel quaternary quinolone derivatives with low toxicity and anti-biofilm activity.
European journal of medicinal chemistry, 291:117591 pii:S0223-5234(25)00356-3 [Epub ahead of print].
To overcome the increasing global drug resistance, the development of novel antimicrobial drugs is a top priority in the fight against multidrug resistant (MDR) and persistent bacteria. In this work, we report the synthesis of novel single quaternary quinolone antibacterial agents. The majority of the tested compounds exhibited significant antimicrobial efficacy against Gram-negative pathogens (E. coli and S. maltophilia). Notably, the selected compound (4e) was highly inhibitory with a MIC value of 0.25 μg/mL against E. coli. Additionally, compound 4e demonstrated excellent stability in complex biological fluids with low hemolytic activity (HC50 > 1280 μg/mL) and a significantly lower propensity to induce bacterial resistance. Encouragingly, 4e showed not only rapid bactericidal activity and inhibition of bacterial biofilms, but also low toxicity to erythrocytes and RAW 264.7 cells compared to the clinical drug ciprofloxacin. Mechanism studies have found that compound 4e has a relatively weak destructive effect on the cell membrane of E. coli. However, it can effectively inhibit the activity of glutathione (GSH), promote the massive accumulation of intracellular reactive oxygen species (ROS), and then disrupt the antioxidant defense system of bacteria, achieving a bactericidal effect. In addition, compound 4e has a certain binding effect with bacterial DNA.
Additional Links: PMID-40186892
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PubMed:
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@article {pmid40186892,
year = {2025},
author = {Qu, Y and Gao, C and Li, R and Wu, Y and Kong, H and Li, Y and Li, D and Ampomah-Wireko, M and Wang, YN and Zhang, E},
title = {Synthesis and antimicrobial evaluation of novel quaternary quinolone derivatives with low toxicity and anti-biofilm activity.},
journal = {European journal of medicinal chemistry},
volume = {291},
number = {},
pages = {117591},
doi = {10.1016/j.ejmech.2025.117591},
pmid = {40186892},
issn = {1768-3254},
abstract = {To overcome the increasing global drug resistance, the development of novel antimicrobial drugs is a top priority in the fight against multidrug resistant (MDR) and persistent bacteria. In this work, we report the synthesis of novel single quaternary quinolone antibacterial agents. The majority of the tested compounds exhibited significant antimicrobial efficacy against Gram-negative pathogens (E. coli and S. maltophilia). Notably, the selected compound (4e) was highly inhibitory with a MIC value of 0.25 μg/mL against E. coli. Additionally, compound 4e demonstrated excellent stability in complex biological fluids with low hemolytic activity (HC50 > 1280 μg/mL) and a significantly lower propensity to induce bacterial resistance. Encouragingly, 4e showed not only rapid bactericidal activity and inhibition of bacterial biofilms, but also low toxicity to erythrocytes and RAW 264.7 cells compared to the clinical drug ciprofloxacin. Mechanism studies have found that compound 4e has a relatively weak destructive effect on the cell membrane of E. coli. However, it can effectively inhibit the activity of glutathione (GSH), promote the massive accumulation of intracellular reactive oxygen species (ROS), and then disrupt the antioxidant defense system of bacteria, achieving a bactericidal effect. In addition, compound 4e has a certain binding effect with bacterial DNA.},
}
RevDate: 2025-04-05
CmpDate: 2025-04-05
Deciphering antibiotic resistance, quorum sensing, and biofilm forming genes of Micrococcus luteus from hemodialysis tunneled cuffed catheter tips of renal failure patients.
Archives of microbiology, 207(5):114.
Catheter-related bloodstream infections create a significant challenge in healthcare system, often complicated by antibiotic resistance and biofilm formation of multi-drug resistance and virulent bacterial pathogens. This study focused on biofilm-forming efficiency, and underlying genetic mechanisms in Micrococcus luteus HL_Chru_C3, isolated from a hemodialysis catheter tip. The isolate exhibited resistance to multiple antibiotic classes, including beta-lactams and glycopeptides. Biofilm assays revealed that M. luteus HL_Chru_C3 formed optimum biofilms at high concentration of carbohydrates (500 mM), and pH 5 but there was no significant role of mineral salts. Whole-genome sequencing and bioinformatic analysis using CARD, KAAS, and KEGG databases identified genes associated with antibiotic resistance (ftsI, pbp1a/2, vanY, alr, ddl, murF, mraY, and murG), quorum sensing (genes from the opp family, sec, cylA, ccfA, phnA, phnB, phzC, rpfB, clp, and toxE), and biofilm formation (phnA, phnB, cyaB, vfr, vps, glgC, wecB, wecC, and cysE). The predicted mechanisms of action for these genes, based on homology to other organisms, suggest complex interactions contributing to the observed phenotypes. This study provides an insight into the genetic basis of antibiotic resistance and biofilm formation in M. luteus HL_Chru_C3 isolated from a hemodialysis catheter, highlighting the need for effective infection control strategies to combat CRBSIs.
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@article {pmid40186781,
year = {2025},
author = {Adhikary, R and Sarkar, I and Patel, D and Gang, S and Nath, UK and Hazra, S},
title = {Deciphering antibiotic resistance, quorum sensing, and biofilm forming genes of Micrococcus luteus from hemodialysis tunneled cuffed catheter tips of renal failure patients.},
journal = {Archives of microbiology},
volume = {207},
number = {5},
pages = {114},
pmid = {40186781},
issn = {1432-072X},
support = {IIRPIG-2023-0000773//Indian Council of Medical Research/ ; IIRPIG-2023-0000773//Indian Council of Medical Research/ ; IIRPIG-2023-0000773//Indian Council of Medical Research/ ; IIRPIG-2023-0000773//Indian Council of Medical Research/ ; },
mesh = {*Biofilms/growth & development ; *Quorum Sensing/genetics ; *Micrococcus luteus/genetics/drug effects/physiology/isolation & purification ; *Renal Dialysis/adverse effects/instrumentation ; Humans ; Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; Catheter-Related Infections/microbiology ; Whole Genome Sequencing ; Bacterial Proteins/genetics ; Drug Resistance, Multiple, Bacterial/genetics ; *Drug Resistance, Bacterial/genetics ; },
abstract = {Catheter-related bloodstream infections create a significant challenge in healthcare system, often complicated by antibiotic resistance and biofilm formation of multi-drug resistance and virulent bacterial pathogens. This study focused on biofilm-forming efficiency, and underlying genetic mechanisms in Micrococcus luteus HL_Chru_C3, isolated from a hemodialysis catheter tip. The isolate exhibited resistance to multiple antibiotic classes, including beta-lactams and glycopeptides. Biofilm assays revealed that M. luteus HL_Chru_C3 formed optimum biofilms at high concentration of carbohydrates (500 mM), and pH 5 but there was no significant role of mineral salts. Whole-genome sequencing and bioinformatic analysis using CARD, KAAS, and KEGG databases identified genes associated with antibiotic resistance (ftsI, pbp1a/2, vanY, alr, ddl, murF, mraY, and murG), quorum sensing (genes from the opp family, sec, cylA, ccfA, phnA, phnB, phzC, rpfB, clp, and toxE), and biofilm formation (phnA, phnB, cyaB, vfr, vps, glgC, wecB, wecC, and cysE). The predicted mechanisms of action for these genes, based on homology to other organisms, suggest complex interactions contributing to the observed phenotypes. This study provides an insight into the genetic basis of antibiotic resistance and biofilm formation in M. luteus HL_Chru_C3 isolated from a hemodialysis catheter, highlighting the need for effective infection control strategies to combat CRBSIs.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Quorum Sensing/genetics
*Micrococcus luteus/genetics/drug effects/physiology/isolation & purification
*Renal Dialysis/adverse effects/instrumentation
Humans
Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests
Catheter-Related Infections/microbiology
Whole Genome Sequencing
Bacterial Proteins/genetics
Drug Resistance, Multiple, Bacterial/genetics
*Drug Resistance, Bacterial/genetics
RevDate: 2025-04-05
Scaling up biofilm bioreactors for enhanced menaquinone-7 production.
Bioprocess and biosystems engineering [Epub ahead of print].
The health benefits of menaquinone-7 (MK-7) are well-established, and its production through fermentation techniques is widespread. Our team developed an innovative biofilm reactor utilizing Bacillus subtilis natto cells to foster biofilm growth on plastic composite supports to produce MK-7. The scalability of this biofilm reactor from a 2-L benchtop scale in our laboratory and its potential for commercial applications pose significant unresolved questions. Therefore, the current research was aimed to scale up the biofilm reactor from bench scale (2-L) to the pilot scale (30-L) bioreactor. Three strategies were evaluated to understand their impact on MK-7 biosynthesis during bioreactor volume expansion: volumetric oxygen mass transfer coefficient (kLa), agitation power input per unit volume (P/V), and impeller tip velocity (Vtip). While kLa was successfully maintained during scaling, P/V and Vtip varied and were assessed for their influence on MK-7 production. After investigating these methods, it was found that the volumetric oxygen mass transfer coefficient (kLa) constant method proved to be the most effective one. The optimum MK-7 concentration achieved was 21.0 ± 1.0 mg/L, comparable to the highest MK-7 concentration of 20.6 ± 1.0 attained at the 2-L scale. This showcases the scalability of biofilm bioreactor technology and its promising potential for commercial production of MK-7. Furthermore, we explored the potential of fed-batch glucose addition to the base media in the biofilm reactor to enhance MK-7 concentration at the 30-L scale. Remarkably, results demonstrated that fed-batch strategy significantly increased MK-7 concentrations to 28.7 ± 0.3 mg/L, which made it almost 2.3-fold higher than levels produced in suspended-cell bioreactors. This finding highlights the potential of biofilm reactors as a promising replacement to the current static fermentation strategies for commercial production of MK-7.
Additional Links: PMID-40186773
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@article {pmid40186773,
year = {2025},
author = {Berenjian, A and Mahdinia, E and Demirci, A},
title = {Scaling up biofilm bioreactors for enhanced menaquinone-7 production.},
journal = {Bioprocess and biosystems engineering},
volume = {},
number = {},
pages = {},
pmid = {40186773},
issn = {1615-7605},
support = {Project #PEN04850 (Accession #7005668) and Project #PEN04876 (Accession #7005757)//USDA National Institute of Food and Agriculture Federal Appropriations/ ; },
abstract = {The health benefits of menaquinone-7 (MK-7) are well-established, and its production through fermentation techniques is widespread. Our team developed an innovative biofilm reactor utilizing Bacillus subtilis natto cells to foster biofilm growth on plastic composite supports to produce MK-7. The scalability of this biofilm reactor from a 2-L benchtop scale in our laboratory and its potential for commercial applications pose significant unresolved questions. Therefore, the current research was aimed to scale up the biofilm reactor from bench scale (2-L) to the pilot scale (30-L) bioreactor. Three strategies were evaluated to understand their impact on MK-7 biosynthesis during bioreactor volume expansion: volumetric oxygen mass transfer coefficient (kLa), agitation power input per unit volume (P/V), and impeller tip velocity (Vtip). While kLa was successfully maintained during scaling, P/V and Vtip varied and were assessed for their influence on MK-7 production. After investigating these methods, it was found that the volumetric oxygen mass transfer coefficient (kLa) constant method proved to be the most effective one. The optimum MK-7 concentration achieved was 21.0 ± 1.0 mg/L, comparable to the highest MK-7 concentration of 20.6 ± 1.0 attained at the 2-L scale. This showcases the scalability of biofilm bioreactor technology and its promising potential for commercial production of MK-7. Furthermore, we explored the potential of fed-batch glucose addition to the base media in the biofilm reactor to enhance MK-7 concentration at the 30-L scale. Remarkably, results demonstrated that fed-batch strategy significantly increased MK-7 concentrations to 28.7 ± 0.3 mg/L, which made it almost 2.3-fold higher than levels produced in suspended-cell bioreactors. This finding highlights the potential of biofilm reactors as a promising replacement to the current static fermentation strategies for commercial production of MK-7.},
}
RevDate: 2025-04-07
Microbiome and biofilm insights from normal vs tumor tissues in Thai colorectal cancer patients.
NPJ precision oncology, 9(1):98.
Colorectal cancer (CRC) is a prevalent global malignancy with complex etiologies, including microbiota alterations. This study investigates gut microbiota and biofilm-producing bacteria in 35 Thai CRC patients, analyzing paired normal and tumor biopsy samples. Bacterial DNA from the V3-V4 region of 16S rRNA was sequenced, and biofilms were visualized via scanning electron microscopy and fluorescence in situ hybridization (FISH). Results revealed Firmicutes as the dominant phylum, followed by Bacteroidota, Proteobacteria, and Fusobacteriota, with Fusobacteriota and Bacteroidota notably enriched in left-sided CRC. Key biofilm producers-Bacteroides fragilis, Fusobacterium nucleatum, and Pasteurella stomatis-showed significantly higher gene expression in tumor tissues. Dense biofilms and higher Fusobacterium abundance, localized within the crypts of Lieberkuhn, were observed in CRC tissues. These findings highlight CRC-associated microbiota alterations and pathogenic biofilm production, emphasizing a spatial relationship between tumor location and microbial distribution, with potential implications for understanding CRC pathogenesis and therapeutic targeting.
Additional Links: PMID-40185839
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@article {pmid40185839,
year = {2025},
author = {Yincharoen, P and Mordmuang, A and Techarang, T and Tangngamsakul, P and Kaewubon, P and Atipairin, P and Janwanitchasthaporn, S and Goodla, L and Karnjana, K},
title = {Microbiome and biofilm insights from normal vs tumor tissues in Thai colorectal cancer patients.},
journal = {NPJ precision oncology},
volume = {9},
number = {1},
pages = {98},
pmid = {40185839},
issn = {2397-768X},
abstract = {Colorectal cancer (CRC) is a prevalent global malignancy with complex etiologies, including microbiota alterations. This study investigates gut microbiota and biofilm-producing bacteria in 35 Thai CRC patients, analyzing paired normal and tumor biopsy samples. Bacterial DNA from the V3-V4 region of 16S rRNA was sequenced, and biofilms were visualized via scanning electron microscopy and fluorescence in situ hybridization (FISH). Results revealed Firmicutes as the dominant phylum, followed by Bacteroidota, Proteobacteria, and Fusobacteriota, with Fusobacteriota and Bacteroidota notably enriched in left-sided CRC. Key biofilm producers-Bacteroides fragilis, Fusobacterium nucleatum, and Pasteurella stomatis-showed significantly higher gene expression in tumor tissues. Dense biofilms and higher Fusobacterium abundance, localized within the crypts of Lieberkuhn, were observed in CRC tissues. These findings highlight CRC-associated microbiota alterations and pathogenic biofilm production, emphasizing a spatial relationship between tumor location and microbial distribution, with potential implications for understanding CRC pathogenesis and therapeutic targeting.},
}
RevDate: 2025-04-04
ArcAB system promotes biofilm formation through direct repression of hapR transcription in Vibrio cholerae.
Microbiological research, 297:128155 pii:S0944-5013(25)00111-9 [Epub ahead of print].
Vibrio cholerae, the causative agent of cholera, can efficiently adapt its metabolic processes, including biofilm formation, in response to varying respiratory conditions- such as aerobic, microaerobic, and anaerobic- through the ArcAB system. In this study, we elucidate the activation mechanism of V. cholerae ArcB and ArcA and identify ArcB residues H292, D577, and H722, along with ArcA residue D54 as key phosphorylation sites. Furthermore, we demonstrate that the ArcAB system plays a crucial role in regulating biofilm formation under both aerobic and anaerobic conditions. Our findings reveal that the positive regulation of biofilm formation by the ArcAB systems involves the high cell density (HCD) quorum sensing (QS) regulator HapR. Specifically, phosphorylated ArcA represses hapR transcription, thereby promoting biofilm formation under anaerobic condition. This study also highlights an epistatic relationship between ArcA and HapR in biofilm regulation. Overall, our results underscore the critical role of the ArcAB system in the biofilm formation of pathogenic V. cholerae under oxygen-limiting conditions.
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@article {pmid40185028,
year = {2025},
author = {Caigoy, JC and Nariya, H and Shimamoto, T and Yan, Z and Shimamoto, T},
title = {ArcAB system promotes biofilm formation through direct repression of hapR transcription in Vibrio cholerae.},
journal = {Microbiological research},
volume = {297},
number = {},
pages = {128155},
doi = {10.1016/j.micres.2025.128155},
pmid = {40185028},
issn = {1618-0623},
abstract = {Vibrio cholerae, the causative agent of cholera, can efficiently adapt its metabolic processes, including biofilm formation, in response to varying respiratory conditions- such as aerobic, microaerobic, and anaerobic- through the ArcAB system. In this study, we elucidate the activation mechanism of V. cholerae ArcB and ArcA and identify ArcB residues H292, D577, and H722, along with ArcA residue D54 as key phosphorylation sites. Furthermore, we demonstrate that the ArcAB system plays a crucial role in regulating biofilm formation under both aerobic and anaerobic conditions. Our findings reveal that the positive regulation of biofilm formation by the ArcAB systems involves the high cell density (HCD) quorum sensing (QS) regulator HapR. Specifically, phosphorylated ArcA represses hapR transcription, thereby promoting biofilm formation under anaerobic condition. This study also highlights an epistatic relationship between ArcA and HapR in biofilm regulation. Overall, our results underscore the critical role of the ArcAB system in the biofilm formation of pathogenic V. cholerae under oxygen-limiting conditions.},
}
RevDate: 2025-04-04
Growth on Hydrogen by the Sulfate-Reducing Oleidesulfovibrio alaskensis Induces Biofilm Dispersion and Detachment─Implications for Underground Hydrogen Storage.
Environmental science & technology [Epub ahead of print].
Hydrogen is a versatile energy carrier for human activity but is also a ubiquitous electron donor for subsurface microorganisms. During underground hydrogen storage operations, it is expected that microbial communities will use the injected hydrogen as electron donor for diverse metabolisms, and induce a variety of microbial-triggered risks. A significant concern is the formation of biofilm and induced bioclogging, which may reduce the hydrogen injectivity and storage operation efficiency by altering the subsurface hydrogen flow. This study investigates how different electron donors─specifically hydrogen and lactate─affect the growth dynamics of a sulfate-reducing bacterium (Oleidesulfovibrio alaskensis G20) and the associated biofilm formation in porous media. The pore-scale observations reveal that lactate promotes robust biofilms resulting in bioclogging, compared to hydrogen promoting increased microbial motility with less biomass production. Potential hydrogen chemotaxis leads to biofilm dispersal and detachment over time as the cells seemingly favor a planktonic lifestyle over biofilm formation. Multiple hydrogen injections enhanced biofilm detachment and reduced the risk of pore blockage associated with microbial growth. Three hydrogen injections resulted in 69% biofilm detachment, while nitrogen injection caused only 31% detachment over three cycles. The combination of increased cell motility and reduced biofilm attachment indicates that the risk of bioclogging during cyclic UHS operation might be low for this model bacterial strain.
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@article {pmid40184536,
year = {2025},
author = {Liu, N and Ostertag-Henning, C and Fernø, MA and Dopffel, N},
title = {Growth on Hydrogen by the Sulfate-Reducing Oleidesulfovibrio alaskensis Induces Biofilm Dispersion and Detachment─Implications for Underground Hydrogen Storage.},
journal = {Environmental science & technology},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.est.4c13893},
pmid = {40184536},
issn = {1520-5851},
abstract = {Hydrogen is a versatile energy carrier for human activity but is also a ubiquitous electron donor for subsurface microorganisms. During underground hydrogen storage operations, it is expected that microbial communities will use the injected hydrogen as electron donor for diverse metabolisms, and induce a variety of microbial-triggered risks. A significant concern is the formation of biofilm and induced bioclogging, which may reduce the hydrogen injectivity and storage operation efficiency by altering the subsurface hydrogen flow. This study investigates how different electron donors─specifically hydrogen and lactate─affect the growth dynamics of a sulfate-reducing bacterium (Oleidesulfovibrio alaskensis G20) and the associated biofilm formation in porous media. The pore-scale observations reveal that lactate promotes robust biofilms resulting in bioclogging, compared to hydrogen promoting increased microbial motility with less biomass production. Potential hydrogen chemotaxis leads to biofilm dispersal and detachment over time as the cells seemingly favor a planktonic lifestyle over biofilm formation. Multiple hydrogen injections enhanced biofilm detachment and reduced the risk of pore blockage associated with microbial growth. Three hydrogen injections resulted in 69% biofilm detachment, while nitrogen injection caused only 31% detachment over three cycles. The combination of increased cell motility and reduced biofilm attachment indicates that the risk of bioclogging during cyclic UHS operation might be low for this model bacterial strain.},
}
RevDate: 2025-04-05
Alpha-bisabolol inhibits yeast to hyphal form transition and biofilm development in Candida albicans: in vitro and in silico studies.
In silico pharmacology, 13(1):53.
In recent years, there has been growing concern about infections caused by Candida albicans, which pose a significant threat to human health. This intensifies the concern that can be largely attributed to the increasing number of people with compromised immune systems and the emergence of drug-resistant strains. Natural molecules are considered to be good alternatives to synthetic antifungal agents. The present study explored the effectiveness of alpha-bisabolol as an antifungal agent and its mechanism of action against C. albicans ATCC90028. α-bisabolol effectively inhibited various pathogenic traits of C. albicans like, adhesion, yeast to hyphal switching, and development of biofilm at 1 mg/ml, 0.25 mg/ml, and 0.125 mg/ml concentration, respectively. In addition, α-bisabolol demonstrated inhibition of cell cycle propagation at the G1 phase. Ergosterol production in the C. albicans was suppressed by α-bisabolol treatment in a dose-dependent manner. The molecular docking study revealed α-bisabolol has a good binding energy of - 7.11 kcal/mol with 14-α-demethylase enzyme, which is crucial for ergosterol synthesis. Therefore, the cell membrane integrity may be affected by treatment with α-bisabolol. qRT-PCR studies proved that α-bisabolol treatment affects gene expression in C. albicans. In silico binding affinity was also analyzed for RAS1, TUP1 and CST20 in the signal transduction pathway and exhibited binding affinities for at - 7.7 kcal/mol, - 8.21 kcal/mol, and for - 5.79 kcal/mol respectively. In conclusion, α-bisabolol caused reduced biofilm, ergosterol synthesis along with altered gene expressions in C. albicans with no hemolysis. This study proposed α-bisabolol as an alternative antifungal agent.
Additional Links: PMID-40182396
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@article {pmid40182396,
year = {2025},
author = {Chougule, S and Patil, S and Gavandi, T and Basrani, S and Jadhav, AK and Karuppayil, SM},
title = {Alpha-bisabolol inhibits yeast to hyphal form transition and biofilm development in Candida albicans: in vitro and in silico studies.},
journal = {In silico pharmacology},
volume = {13},
number = {1},
pages = {53},
pmid = {40182396},
issn = {2193-9616},
abstract = {In recent years, there has been growing concern about infections caused by Candida albicans, which pose a significant threat to human health. This intensifies the concern that can be largely attributed to the increasing number of people with compromised immune systems and the emergence of drug-resistant strains. Natural molecules are considered to be good alternatives to synthetic antifungal agents. The present study explored the effectiveness of alpha-bisabolol as an antifungal agent and its mechanism of action against C. albicans ATCC90028. α-bisabolol effectively inhibited various pathogenic traits of C. albicans like, adhesion, yeast to hyphal switching, and development of biofilm at 1 mg/ml, 0.25 mg/ml, and 0.125 mg/ml concentration, respectively. In addition, α-bisabolol demonstrated inhibition of cell cycle propagation at the G1 phase. Ergosterol production in the C. albicans was suppressed by α-bisabolol treatment in a dose-dependent manner. The molecular docking study revealed α-bisabolol has a good binding energy of - 7.11 kcal/mol with 14-α-demethylase enzyme, which is crucial for ergosterol synthesis. Therefore, the cell membrane integrity may be affected by treatment with α-bisabolol. qRT-PCR studies proved that α-bisabolol treatment affects gene expression in C. albicans. In silico binding affinity was also analyzed for RAS1, TUP1 and CST20 in the signal transduction pathway and exhibited binding affinities for at - 7.7 kcal/mol, - 8.21 kcal/mol, and for - 5.79 kcal/mol respectively. In conclusion, α-bisabolol caused reduced biofilm, ergosterol synthesis along with altered gene expressions in C. albicans with no hemolysis. This study proposed α-bisabolol as an alternative antifungal agent.},
}
RevDate: 2025-04-05
Study on the invitro synergistic susceptibility and biofilm inhibition mechanism of ceftazidime-avibactam combined with aztreonam against carbapenem-resistant Klebsiella pneumoniae.
Frontiers in microbiology, 16:1542029.
OBJECTIVE: This study aims to investigate the synergistic effects and biofilm inhibition mechanisms of ceftazidime-avibactam (CZA) combined with aztreonam (ATM) against carbapenem-resistant Klebsiella pneumonia (CRKP) commonly found in the local clinical setting, providing new insights for clinical anti-infective strategies.
METHODS: We selected a total of 150 non-duplicate clinical isolates of CRKP from multiple hospitals in Ningbo. Common carbapenemase genes were detected using PCR. Broth microdilution and time-kill assays were used to evaluate the in vitro synergistic effects of CZA and ATM, both individually and in combination, on CRKP isolates with different enzyme types, and the fractional inhibitory concentration index (FICI) was calculated. The crystal violet staining method and bacterial cell permeability assay were employed to assess the impact of CZA, ATM, and their combination on the cell structure and biofilm formation capacity of CRKP. Real-time quantitative PCR (qRT-PCR) was used to measure the expression levels of biofilm-related genes (Luxs, mrkA, wbbM, pgaA, and wzm) in CRKP under treatment with CZA, ATM, or their combination.
RESULTS: The comparison of synergistic indices for different enzyme-type CRKP strains with CZA and ATM combination therapy showed a statistically significant difference (p < 0.01). The time-kill assay indicated that the time-kill curves for strains carrying blaKPC-2 and blaNDM-1 resistance genes were similar between the monotherapy and combination therapy groups, while the CZA + ATM combination therapy group showed a significant decrease in bacterial concentration after 4-8 h of cultivation compared to the CZA and ATM monotherapy groups. The crystal violet staining and bacterial cell permeability assays demonstrated that the CZA + ATM combination significantly reduced biofilm formation and increased cellular structure disruption in CRKP. The qRT-PCR results showed that CZA combined with ATM notably decreased the expression levels of biofilm-related genes Luxs, mrkA, wbbM, pgaA, and wzm in CRKP.
CONCLUSION: The combination of ATM and CZA shows a strong synergistic antibacterial effect against CRKP strains with various enzyme types, with particularly notable synergy in strains carrying the blaKPC-2 resistance gene. Additionally, this combination significantly disrupts the cellular structure of CRKP and inhibits biofilm formation.
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@article {pmid40182285,
year = {2025},
author = {Wang, G and Zhang, H and Wu, Q and Xu, J and Qiu, X and Chen, J and Cui, F and Zhou, J and Li, Q},
title = {Study on the invitro synergistic susceptibility and biofilm inhibition mechanism of ceftazidime-avibactam combined with aztreonam against carbapenem-resistant Klebsiella pneumoniae.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1542029},
pmid = {40182285},
issn = {1664-302X},
abstract = {OBJECTIVE: This study aims to investigate the synergistic effects and biofilm inhibition mechanisms of ceftazidime-avibactam (CZA) combined with aztreonam (ATM) against carbapenem-resistant Klebsiella pneumonia (CRKP) commonly found in the local clinical setting, providing new insights for clinical anti-infective strategies.
METHODS: We selected a total of 150 non-duplicate clinical isolates of CRKP from multiple hospitals in Ningbo. Common carbapenemase genes were detected using PCR. Broth microdilution and time-kill assays were used to evaluate the in vitro synergistic effects of CZA and ATM, both individually and in combination, on CRKP isolates with different enzyme types, and the fractional inhibitory concentration index (FICI) was calculated. The crystal violet staining method and bacterial cell permeability assay were employed to assess the impact of CZA, ATM, and their combination on the cell structure and biofilm formation capacity of CRKP. Real-time quantitative PCR (qRT-PCR) was used to measure the expression levels of biofilm-related genes (Luxs, mrkA, wbbM, pgaA, and wzm) in CRKP under treatment with CZA, ATM, or their combination.
RESULTS: The comparison of synergistic indices for different enzyme-type CRKP strains with CZA and ATM combination therapy showed a statistically significant difference (p < 0.01). The time-kill assay indicated that the time-kill curves for strains carrying blaKPC-2 and blaNDM-1 resistance genes were similar between the monotherapy and combination therapy groups, while the CZA + ATM combination therapy group showed a significant decrease in bacterial concentration after 4-8 h of cultivation compared to the CZA and ATM monotherapy groups. The crystal violet staining and bacterial cell permeability assays demonstrated that the CZA + ATM combination significantly reduced biofilm formation and increased cellular structure disruption in CRKP. The qRT-PCR results showed that CZA combined with ATM notably decreased the expression levels of biofilm-related genes Luxs, mrkA, wbbM, pgaA, and wzm in CRKP.
CONCLUSION: The combination of ATM and CZA shows a strong synergistic antibacterial effect against CRKP strains with various enzyme types, with particularly notable synergy in strains carrying the blaKPC-2 resistance gene. Additionally, this combination significantly disrupts the cellular structure of CRKP and inhibits biofilm formation.},
}
RevDate: 2025-04-05
Complete genome sequence, metabolic profiling and functional studies reveal Ligilactobacillus salivarius LS-ARS2 is a promising biofilm-forming probiotic with significant antioxidant, antibacterial, and antibiofilm potential.
Frontiers in microbiology, 16:1535388.
BACKGROUND: Probiotics restore microbial balance and prevent gut-inflammation. Therefore, finding out novel probiotic strains is a demand. As gut-microbe, benefits of Ligilactobacillus salivarius (LS) are established. However, strain-specific detailed studies are limited. Here, we illustrate probiotic attributes of novel LS-ARS2 for its potential application as food-supplement and/or therapeutic to improve gut-health.
METHODS: Whole genome sequencing (WGS) and phylogenetic analysis confirm the strain as LS. To establish probiotic properties, acid-bile tolerance, auto-aggregation, cell-surface-hydrophobicity, biofilm-formation, and adhesion-assays are performed. To ensure safety attributes, antibiotic-susceptibility, hemolytic, DNase, trypan-blue, and MTT assays are done. ABTS, DPPH, superoxide, hydroxyl free radical scavenging assays are used to determine anti-oxidant potential. Antibacterial assays, including co-culture assay with pathogen and pathogenic biofilm-inhibition assays, are performed to explore antibacterial efficacy. To characterize metabolic-profile of LS-ARS2-derived cell-free-supernatant (CFS), HRMS analysis are carried out. Consequently, WGS-analyses predict potential molecular associations related to functional outcomes.
RESULTS: We find LS-ARS2 a remarkable fast-growing strain that shows acid and bile tolerance (>60% survival rate), indicating promising gut-sustainability. High auto-aggregation capacity (>80%), robust cell-surface hydrophobicity (>85%), and adhesion efficacy to Caco-2 cells illustrate significant potential of LS-ARS2 for gut colonization. Fascinatingly, LS-ARS2 is able to form biofilm within 24 h (p < 0.0001), rare among LS strains, indicating the potential of the strain for efficient stay in the gut. The strain ensures safety attributes. LS-ARS2-WGS analysis recognizes probiotic-specific determinants, predicts genomic stability, identifies orthologous-clusters for diverse functions, and predicts metabolites and bacteriocins. HRMS-studies with LS-ARS2-CFS further validate the presence of diverse beneficial metabolites with antimicrobial and immunomodulatory potential. LS-ARS2 shows significant antioxidant properties in ABTS (>60%), DPPH (>10 U/mL), superoxide (>70%), and hydroxyl free radical scavenging assays (>70%). Further, LS-ARS2 shows antimicrobial activities against Gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative multidrug-resistant clinical strains enterotoxigenic Escherichia coli, Vibrio cholerae, and Shigella flexneri. Anti-Salmonella effect of LS-ARS2 is prominent (p < 0.0001). Most interestingly, LS-ARS2-CFS inhibits MRSA-biofilm (p < 0.0001), again rare among LS strains.
CONCLUSION: LS-ARS2 is a novel, fast-growing, biofilm-forming probiotic with significant antioxidant, antibacterial, and anti-biofilm potentials, suggesting the promising applications of LS-ARS2 for combating pathogenic biofilms and improving gut-health. However, further in vivo studies would facilitate their potential applications.
Additional Links: PMID-40182284
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@article {pmid40182284,
year = {2025},
author = {Patra, S and Pradhan, B and Roychowdhury, A},
title = {Complete genome sequence, metabolic profiling and functional studies reveal Ligilactobacillus salivarius LS-ARS2 is a promising biofilm-forming probiotic with significant antioxidant, antibacterial, and antibiofilm potential.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1535388},
pmid = {40182284},
issn = {1664-302X},
abstract = {BACKGROUND: Probiotics restore microbial balance and prevent gut-inflammation. Therefore, finding out novel probiotic strains is a demand. As gut-microbe, benefits of Ligilactobacillus salivarius (LS) are established. However, strain-specific detailed studies are limited. Here, we illustrate probiotic attributes of novel LS-ARS2 for its potential application as food-supplement and/or therapeutic to improve gut-health.
METHODS: Whole genome sequencing (WGS) and phylogenetic analysis confirm the strain as LS. To establish probiotic properties, acid-bile tolerance, auto-aggregation, cell-surface-hydrophobicity, biofilm-formation, and adhesion-assays are performed. To ensure safety attributes, antibiotic-susceptibility, hemolytic, DNase, trypan-blue, and MTT assays are done. ABTS, DPPH, superoxide, hydroxyl free radical scavenging assays are used to determine anti-oxidant potential. Antibacterial assays, including co-culture assay with pathogen and pathogenic biofilm-inhibition assays, are performed to explore antibacterial efficacy. To characterize metabolic-profile of LS-ARS2-derived cell-free-supernatant (CFS), HRMS analysis are carried out. Consequently, WGS-analyses predict potential molecular associations related to functional outcomes.
RESULTS: We find LS-ARS2 a remarkable fast-growing strain that shows acid and bile tolerance (>60% survival rate), indicating promising gut-sustainability. High auto-aggregation capacity (>80%), robust cell-surface hydrophobicity (>85%), and adhesion efficacy to Caco-2 cells illustrate significant potential of LS-ARS2 for gut colonization. Fascinatingly, LS-ARS2 is able to form biofilm within 24 h (p < 0.0001), rare among LS strains, indicating the potential of the strain for efficient stay in the gut. The strain ensures safety attributes. LS-ARS2-WGS analysis recognizes probiotic-specific determinants, predicts genomic stability, identifies orthologous-clusters for diverse functions, and predicts metabolites and bacteriocins. HRMS-studies with LS-ARS2-CFS further validate the presence of diverse beneficial metabolites with antimicrobial and immunomodulatory potential. LS-ARS2 shows significant antioxidant properties in ABTS (>60%), DPPH (>10 U/mL), superoxide (>70%), and hydroxyl free radical scavenging assays (>70%). Further, LS-ARS2 shows antimicrobial activities against Gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative multidrug-resistant clinical strains enterotoxigenic Escherichia coli, Vibrio cholerae, and Shigella flexneri. Anti-Salmonella effect of LS-ARS2 is prominent (p < 0.0001). Most interestingly, LS-ARS2-CFS inhibits MRSA-biofilm (p < 0.0001), again rare among LS strains.
CONCLUSION: LS-ARS2 is a novel, fast-growing, biofilm-forming probiotic with significant antioxidant, antibacterial, and anti-biofilm potentials, suggesting the promising applications of LS-ARS2 for combating pathogenic biofilms and improving gut-health. However, further in vivo studies would facilitate their potential applications.},
}
RevDate: 2025-04-05
Exploring the antibacterial and anti-biofilm properties of Diacerein against methicillin-resistant Staphylococcus aureus.
Frontiers in microbiology, 16:1545902.
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant clinical challenge due to its multidrug resistance. Diacerein (DIA), primarily used to treat degenerative joint diseases, has recently been found to exhibit antibacterial activity, though its specific antibacterial mechanisms remain unclear.
METHODS: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of DIA, as well as in - vitro combination susceptibility testing, were determined using the broth microdilution method. Additionally, resistance induction assays, time-growth curve measurements, membrane fluidity, intracellular protein levels, and reactive oxygen species (ROS) were assessed. The inhibition and clearance of MRSA biofilms by DIA were evaluated using the crystal violet staining method, with bacterial morphology and biofilms observed via scanning electron microscopy and confocal laser scanning microscopy. Finally, transcriptome analysis was conducted to identify gene expression changes in MRSA treated with DIA, and RT-qPCR verification was performed.
RESULTS: The MIC and MBC of DIA against MRSA were 32 μg/mL and 128 μg/mL, respectively, and synergistic antibacterial effects when combined with ampicillin. DIA increased intracellular ROS levels and membrane fluidity in MRSA, decreased soluble protein synthesis, and altered bacterial morphology. Additionally, DIA significantly inhibited MRSA biofilm formation and disrupted pre - existing biofilms. Transcriptome analysis revealed 1,045 differentially expressed genes between the DIA-treated group and the control group, primarily involving pathways such as the tricarboxylic acid cycle, phosphorylation, ribosome metabolism, and nucleotide metabolism.
CONCLUSION: In summary, DIA has antibacterial and anti-biofilm activities against MRSA and does not easily induce resistance. Its antibacterial mechanisms may involve multiple aspects, including bacterial protein synthesis, energy metabolism.
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@article {pmid40182283,
year = {2025},
author = {Sun, Y and Wu, Y and Chang, Y and Sun, G and Wang, X and Lu, Z and Li, K and Liang, X and Liu, Q and Wang, W and Wei, L},
title = {Exploring the antibacterial and anti-biofilm properties of Diacerein against methicillin-resistant Staphylococcus aureus.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1545902},
pmid = {40182283},
issn = {1664-302X},
abstract = {BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant clinical challenge due to its multidrug resistance. Diacerein (DIA), primarily used to treat degenerative joint diseases, has recently been found to exhibit antibacterial activity, though its specific antibacterial mechanisms remain unclear.
METHODS: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of DIA, as well as in - vitro combination susceptibility testing, were determined using the broth microdilution method. Additionally, resistance induction assays, time-growth curve measurements, membrane fluidity, intracellular protein levels, and reactive oxygen species (ROS) were assessed. The inhibition and clearance of MRSA biofilms by DIA were evaluated using the crystal violet staining method, with bacterial morphology and biofilms observed via scanning electron microscopy and confocal laser scanning microscopy. Finally, transcriptome analysis was conducted to identify gene expression changes in MRSA treated with DIA, and RT-qPCR verification was performed.
RESULTS: The MIC and MBC of DIA against MRSA were 32 μg/mL and 128 μg/mL, respectively, and synergistic antibacterial effects when combined with ampicillin. DIA increased intracellular ROS levels and membrane fluidity in MRSA, decreased soluble protein synthesis, and altered bacterial morphology. Additionally, DIA significantly inhibited MRSA biofilm formation and disrupted pre - existing biofilms. Transcriptome analysis revealed 1,045 differentially expressed genes between the DIA-treated group and the control group, primarily involving pathways such as the tricarboxylic acid cycle, phosphorylation, ribosome metabolism, and nucleotide metabolism.
CONCLUSION: In summary, DIA has antibacterial and anti-biofilm activities against MRSA and does not easily induce resistance. Its antibacterial mechanisms may involve multiple aspects, including bacterial protein synthesis, energy metabolism.},
}
RevDate: 2025-04-05
Targeting Chronic Biofilm Infections With Patient-derived Phages: An In Vitro and Ex Vivo Proof-of-concept Study in Patients With Left Ventricular Assist Devices.
Open forum infectious diseases, 12(4):ofaf158.
BACKGROUND: Phage therapy is being reconsidered as a valuable approach to combat antimicrobial resistance. We recently established a personalized phage therapy pipeline in healthy volunteers, where therapeutic phages were isolated from individuals' skin microbiota. In this study, we aim to validate this pipeline in end-stage heart failure patients supported by left ventricular assist devices (LVADs), focusing on phages targeting Staphylococcus epidermidis, a common pathogen responsible for LVAD infections.
METHODS: Over a 2.5-year period, 45 LVAD patients were consistently sampled at their driveline exit sites and foreheads. S epidermidis strains from patients' foreheads were used to amplify patient-specific phages. Newly isolated phages were characterized and tested against S epidermidis isolates (n = 42) from the patient cohort. The virulent phage vB_SepS_BE22, isolated from a patient with a driveline infection, was further tested for its bactericidal activity against S epidermidis biofilms ex vivo with rifampicin on driveline biofilms.
RESULTS: S epidermidis was detected in 32 patients, 3 of whom had driveline infections. Phages were isolated from 8 patients, 6 of which were unique and exhibited narrow host ranges, infecting 19%-52% of S epidermidis strains. vB_SepS_BE22, isolated from patient ID25's microbiota, was the only phage that specifically killed S epidermidis clones linked to a patient's infection. vB_SepS_BE22 also reduced bacterial loads in exponential and stationary phase cultures, as well as in biofilms on drivelines when combined with rifampicin.
CONCLUSIONS: This study validated a personalized phage therapy approach, where phages from a patient's own microbiota can be used in chronic infection settings as therapeutic agents.
Additional Links: PMID-40182131
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@article {pmid40182131,
year = {2025},
author = {Pitton, M and Valente, LG and Oberhaensli, S and Gözel, B and Jakob, SM and Sendi, P and Fürholz, M and Cameron, DR and Que, YA},
title = {Targeting Chronic Biofilm Infections With Patient-derived Phages: An In Vitro and Ex Vivo Proof-of-concept Study in Patients With Left Ventricular Assist Devices.},
journal = {Open forum infectious diseases},
volume = {12},
number = {4},
pages = {ofaf158},
pmid = {40182131},
issn = {2328-8957},
abstract = {BACKGROUND: Phage therapy is being reconsidered as a valuable approach to combat antimicrobial resistance. We recently established a personalized phage therapy pipeline in healthy volunteers, where therapeutic phages were isolated from individuals' skin microbiota. In this study, we aim to validate this pipeline in end-stage heart failure patients supported by left ventricular assist devices (LVADs), focusing on phages targeting Staphylococcus epidermidis, a common pathogen responsible for LVAD infections.
METHODS: Over a 2.5-year period, 45 LVAD patients were consistently sampled at their driveline exit sites and foreheads. S epidermidis strains from patients' foreheads were used to amplify patient-specific phages. Newly isolated phages were characterized and tested against S epidermidis isolates (n = 42) from the patient cohort. The virulent phage vB_SepS_BE22, isolated from a patient with a driveline infection, was further tested for its bactericidal activity against S epidermidis biofilms ex vivo with rifampicin on driveline biofilms.
RESULTS: S epidermidis was detected in 32 patients, 3 of whom had driveline infections. Phages were isolated from 8 patients, 6 of which were unique and exhibited narrow host ranges, infecting 19%-52% of S epidermidis strains. vB_SepS_BE22, isolated from patient ID25's microbiota, was the only phage that specifically killed S epidermidis clones linked to a patient's infection. vB_SepS_BE22 also reduced bacterial loads in exponential and stationary phase cultures, as well as in biofilms on drivelines when combined with rifampicin.
CONCLUSIONS: This study validated a personalized phage therapy approach, where phages from a patient's own microbiota can be used in chronic infection settings as therapeutic agents.},
}
RevDate: 2025-04-05
CmpDate: 2025-04-03
Aggregatibacter actinomycetemcomitans induces biofilm formation of Streptococcus sanguinis on titanium implants.
International journal of implant dentistry, 11(1):29.
PURPOSE: This study aims to investigate the distinct behaviors of single-species and dual-species biofilms formed by Streptococcus sanguinis and Aggregatibacter actinomycetemcomitans on different titanium and implant surfaces. Four types of surfaces were examined: two clinically used implant surfaces, a super-polished surface and a sand-blasted surface of grade 4 titanium.
METHODS: Specimens were incubated with single- and dual-species biofilms for 24 h. Biofilm formation was determined based on the amount of total DNA extracted from the bacteria. In order to specifically determine the biofilm formation of Streptococcus sanguinis, qPCR experiments were carried out. Staining followed by fluorescence microscopy was employed to verify the efficiency of the washing steps.
RESULTS: Biofilm formation by single- and dual-species cultures was observed on all tested implant surfaces. However, a clear influence of surface characteristics on biofilm formation could not be conclusively demonstrated. Mixed cultures of S. sanguinis and A. actinomycetemcomitans (AAC) exhibited increased biofilm formation through the enhanced DNA amount of S. sanguinis. In contrast, this effect was not observed in dual-species cultures of Staphylococcus epidermidis and S. sanguinis.
CONCLUSION: AAC promotes biofilm formation of S. sanguinis, highlighting the significant role of AAC in enhancing biofilm development. Conversely, a definitive conclusion regarding the correlation between titanium implant surface roughness and biofilm formation was not possible. However, our results suggest a tendency that dual-species biofilm formation may be influenced by surface structure.
Additional Links: PMID-40180769
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@article {pmid40180769,
year = {2025},
author = {Schubert, A and Friebel, JM and Bunz, O and Sasse, C and Bürgers, R and Wassmann, T},
title = {Aggregatibacter actinomycetemcomitans induces biofilm formation of Streptococcus sanguinis on titanium implants.},
journal = {International journal of implant dentistry},
volume = {11},
number = {1},
pages = {29},
pmid = {40180769},
issn = {2198-4034},
mesh = {*Biofilms/growth & development ; *Titanium ; *Aggregatibacter actinomycetemcomitans/physiology ; *Dental Implants/microbiology ; Surface Properties ; *Streptococcus sanguis/physiology ; Humans ; },
abstract = {PURPOSE: This study aims to investigate the distinct behaviors of single-species and dual-species biofilms formed by Streptococcus sanguinis and Aggregatibacter actinomycetemcomitans on different titanium and implant surfaces. Four types of surfaces were examined: two clinically used implant surfaces, a super-polished surface and a sand-blasted surface of grade 4 titanium.
METHODS: Specimens were incubated with single- and dual-species biofilms for 24 h. Biofilm formation was determined based on the amount of total DNA extracted from the bacteria. In order to specifically determine the biofilm formation of Streptococcus sanguinis, qPCR experiments were carried out. Staining followed by fluorescence microscopy was employed to verify the efficiency of the washing steps.
RESULTS: Biofilm formation by single- and dual-species cultures was observed on all tested implant surfaces. However, a clear influence of surface characteristics on biofilm formation could not be conclusively demonstrated. Mixed cultures of S. sanguinis and A. actinomycetemcomitans (AAC) exhibited increased biofilm formation through the enhanced DNA amount of S. sanguinis. In contrast, this effect was not observed in dual-species cultures of Staphylococcus epidermidis and S. sanguinis.
CONCLUSION: AAC promotes biofilm formation of S. sanguinis, highlighting the significant role of AAC in enhancing biofilm development. Conversely, a definitive conclusion regarding the correlation between titanium implant surface roughness and biofilm formation was not possible. However, our results suggest a tendency that dual-species biofilm formation may be influenced by surface structure.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Titanium
*Aggregatibacter actinomycetemcomitans/physiology
*Dental Implants/microbiology
Surface Properties
*Streptococcus sanguis/physiology
Humans
RevDate: 2025-04-03
Lytic activity, stability, biofilm disruption capabilities and genomic characterisation of two bacteriophages active against respiratory MRSA.
Journal of applied microbiology pii:8105717 [Epub ahead of print].
AIMS: This study aimed to characterise bacteriophages for potential therapeutic use against Staphylococcus aureus, focusing on clinical respiratory isolates of methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) strains. Specifically, it sought to evaluate phage lytic activity, host range, stability, biofilm disruption capabilities, and overall safety for therapeutic use.
METHODS AND RESULTS: Novel phages, Koomba kaat 1 and Biyabeda mokiny 1, were identified and characterised using microbiological assays and bioinformatics. They exhibited lytic activity against clinical MSSA and MRSA isolates, disrupted biofilms from airway isolates, remained stable for at least one year in storage, and could be aerosolized without significant reductions in activity. Bioinformatic tools were used to assess safety, lifecycle, virulence, and prophage contamination when grown using their original isolation host. Receptor binding proteins within their genomes were also predicted, providing insight into their mechanisms of action. Both phages demonstrated strong efficacy against the clinical isolates tested and demonstrated robust stability under storage and delivery conditions.
CONCLUSIONS: Koomba kaat 1 and Biyabeda mokiny 1 are promising candidates for phage therapy. Their efficacy against clinical S. aureus isolates, ability to break down biofilm, and stability for airway implementation, positions them as valuable tools for addressing persistent airway infections caused by S. aureus.
Additional Links: PMID-40180588
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PubMed:
Citation:
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@article {pmid40180588,
year = {2025},
author = {Iszatt, JJ and Larcombe, AN and Garratt, LW and Stick, SM and Kicic, A},
title = {Lytic activity, stability, biofilm disruption capabilities and genomic characterisation of two bacteriophages active against respiratory MRSA.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jambio/lxaf081},
pmid = {40180588},
issn = {1365-2672},
abstract = {AIMS: This study aimed to characterise bacteriophages for potential therapeutic use against Staphylococcus aureus, focusing on clinical respiratory isolates of methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) strains. Specifically, it sought to evaluate phage lytic activity, host range, stability, biofilm disruption capabilities, and overall safety for therapeutic use.
METHODS AND RESULTS: Novel phages, Koomba kaat 1 and Biyabeda mokiny 1, were identified and characterised using microbiological assays and bioinformatics. They exhibited lytic activity against clinical MSSA and MRSA isolates, disrupted biofilms from airway isolates, remained stable for at least one year in storage, and could be aerosolized without significant reductions in activity. Bioinformatic tools were used to assess safety, lifecycle, virulence, and prophage contamination when grown using their original isolation host. Receptor binding proteins within their genomes were also predicted, providing insight into their mechanisms of action. Both phages demonstrated strong efficacy against the clinical isolates tested and demonstrated robust stability under storage and delivery conditions.
CONCLUSIONS: Koomba kaat 1 and Biyabeda mokiny 1 are promising candidates for phage therapy. Their efficacy against clinical S. aureus isolates, ability to break down biofilm, and stability for airway implementation, positions them as valuable tools for addressing persistent airway infections caused by S. aureus.},
}
RevDate: 2025-04-03
A Novel Approach for Preventing Biofilm Formation on Various Breast Implant Surfaces: Bacteriophage Therapy.
Plastic and reconstructive surgery pii:00006534-990000000-02603 [Epub ahead of print].
BACKGROUND: Capsular contracture is a common complication in breast implant surgery, with subclinical bacterial inflammation being a significant factor. Traditional methods to prevent capsular contracture include antibiotic irrigation and systemic antibiotics. However, the rise of antibiotic-resistant bacteria has driven the need for alternative treatments. Bacteriophages, capable of lysing bacteria and preventing biofilm formation, are emerging as a potential alternative. This study aims to compare the efficacy of local bacteriophage therapy and local antibiotic treatment in preventing biofilm formation on breast implants.
MATERIAL AND METHODS: Fifty-four Wistar Albino rats were divided into three groups: control, antibiotic, and bacteriophage, each with three subgroups for different time points (6 hours, 24 hours, and 30 days). Three types of implant surfaces (smooth, textured, and polyurethane) were incubated with a biofilm-producing strain of Staphylococcus epidermidis before implantation. The implant surfaces in the experimental groups were treated with either antibiotic or bacteriophage solutions before implantation. Samples were collected at 6 hours, 24 hours, and 30 days post-implantation for colony counting and mRNA analysis of the sesI gene.
RESULTS: Both bacteriophage and antibiotic treatments significantly reduced colony counts, and mRNA expression compared to the control group at all time points (p<0.05). No significant difference was found between the antibiotic and bacteriophage groups. Textured and polyurethane implants showed lower bacterial loads in the experimental groups compared to smooth implants.
CONCLUSION: This study highlights bacteriophages as a promising alternative to antibiotics for preventing biofilm formation on breast implants, representing a pioneering effort in demonstrating their potential.
Additional Links: PMID-40178584
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PubMed:
Citation:
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@article {pmid40178584,
year = {2025},
author = {Karasu, O and Ayhan, MS and Duran, M and Sahin, EA and Ayaz, ND and Yalinay, AM},
title = {A Novel Approach for Preventing Biofilm Formation on Various Breast Implant Surfaces: Bacteriophage Therapy.},
journal = {Plastic and reconstructive surgery},
volume = {},
number = {},
pages = {},
doi = {10.1097/PRS.0000000000012132},
pmid = {40178584},
issn = {1529-4242},
abstract = {BACKGROUND: Capsular contracture is a common complication in breast implant surgery, with subclinical bacterial inflammation being a significant factor. Traditional methods to prevent capsular contracture include antibiotic irrigation and systemic antibiotics. However, the rise of antibiotic-resistant bacteria has driven the need for alternative treatments. Bacteriophages, capable of lysing bacteria and preventing biofilm formation, are emerging as a potential alternative. This study aims to compare the efficacy of local bacteriophage therapy and local antibiotic treatment in preventing biofilm formation on breast implants.
MATERIAL AND METHODS: Fifty-four Wistar Albino rats were divided into three groups: control, antibiotic, and bacteriophage, each with three subgroups for different time points (6 hours, 24 hours, and 30 days). Three types of implant surfaces (smooth, textured, and polyurethane) were incubated with a biofilm-producing strain of Staphylococcus epidermidis before implantation. The implant surfaces in the experimental groups were treated with either antibiotic or bacteriophage solutions before implantation. Samples were collected at 6 hours, 24 hours, and 30 days post-implantation for colony counting and mRNA analysis of the sesI gene.
RESULTS: Both bacteriophage and antibiotic treatments significantly reduced colony counts, and mRNA expression compared to the control group at all time points (p<0.05). No significant difference was found between the antibiotic and bacteriophage groups. Textured and polyurethane implants showed lower bacterial loads in the experimental groups compared to smooth implants.
CONCLUSION: This study highlights bacteriophages as a promising alternative to antibiotics for preventing biofilm formation on breast implants, representing a pioneering effort in demonstrating their potential.},
}
RevDate: 2025-04-03
The antimycotic 5-fluorocytosine is a virulence inhibitor of uropathogenic Escherichia coli and eradicates biofilm-embedded bacteria synergizing with β-lactams.
Antimicrobial agents and chemotherapy [Epub ahead of print].
Biofilm can enhance antibiotic tolerance in bacteria, making treatment of biofilm-associated infections in clinical settings a significant challenge. 5-Fluorocytosine (5-FC), an FDA-approved drug mostly used as an antifungal, can hinder biofilm formation and production of virulence factors in Gram-negative bacteria. In this study, we tested 5-FC on nine uropathogenic Escherichia coli (UPEC) strains plus a fecal isolate. Our data indicated that 5-FC reduced curli fiber gene expression and inhibited virulence factors in UPEC strains. Unlike what was observed in other microorganisms, 5-FC antivirulence and antibiofilm properties were unaffected by either growth temperature or the medium pH, which might prove critical in urinary tract infection (UTI) treatment. Additionally, 5-FC impaired the expression of various UPEC virulence factors, including secreted toxins and type I and P fimbriae, thus leading to decreased UPEC adherence to bladder epithelial cells and improved survival of host cells. Finally, we found that a combination of 5-FC with β-lactams, but not other classes of antibiotics, significantly lowered the viability of bacteria in preformed biofilms. Despite a small set of pathogenic E. coli strains and an in vitro infection model, our findings strongly suggest that 5-FC might be a possible candidate as an antivirulence agent, particularly in a synergistic approach with β-lactam antibiotics.
Additional Links: PMID-40178261
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PubMed:
Citation:
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@article {pmid40178261,
year = {2025},
author = {Ravishankar, S and Conte, AL and Carrasco Aliaga, SJ and Baldelli, V and Nielsen, KL and Paroni, M and Conte, MP and Landini, P and Rossi, E},
title = {The antimycotic 5-fluorocytosine is a virulence inhibitor of uropathogenic Escherichia coli and eradicates biofilm-embedded bacteria synergizing with β-lactams.},
journal = {Antimicrobial agents and chemotherapy},
volume = {},
number = {},
pages = {e0028025},
doi = {10.1128/aac.00280-25},
pmid = {40178261},
issn = {1098-6596},
abstract = {Biofilm can enhance antibiotic tolerance in bacteria, making treatment of biofilm-associated infections in clinical settings a significant challenge. 5-Fluorocytosine (5-FC), an FDA-approved drug mostly used as an antifungal, can hinder biofilm formation and production of virulence factors in Gram-negative bacteria. In this study, we tested 5-FC on nine uropathogenic Escherichia coli (UPEC) strains plus a fecal isolate. Our data indicated that 5-FC reduced curli fiber gene expression and inhibited virulence factors in UPEC strains. Unlike what was observed in other microorganisms, 5-FC antivirulence and antibiofilm properties were unaffected by either growth temperature or the medium pH, which might prove critical in urinary tract infection (UTI) treatment. Additionally, 5-FC impaired the expression of various UPEC virulence factors, including secreted toxins and type I and P fimbriae, thus leading to decreased UPEC adherence to bladder epithelial cells and improved survival of host cells. Finally, we found that a combination of 5-FC with β-lactams, but not other classes of antibiotics, significantly lowered the viability of bacteria in preformed biofilms. Despite a small set of pathogenic E. coli strains and an in vitro infection model, our findings strongly suggest that 5-FC might be a possible candidate as an antivirulence agent, particularly in a synergistic approach with β-lactam antibiotics.},
}
RevDate: 2025-04-02
Mitigating chromate toxicity through concurrent denitrification in the H2-based membrane biofilm reactor.
Journal of hazardous materials, 492:138073 pii:S0304-3894(25)00988-4 [Epub ahead of print].
High concentrations of hexavalent chromium (Cr(VI)) in industrial wastewaters pose significant environmental and health hazards. Biotranformation is a viable means to lower Cr(VI) toxicity, but research to date has focused on wastewaters with low concentrations (e.g., 2-5 mg/L Cr(VI)). This study evaluated the dynamics of biosorption and biotransformation of higher-concentration Cr(VI) by biofilms in the H2-based membrane biofilm reactor (MBfR). While the biofilm in an MBfR receiving Cr(VI) alone had limited capacity to remove Cr(VI) and Cr(VI) removal ceased in 30 days, an autotrophic denitrifying biofilms achieved 99 % reduction of over 20 mg/L Cr(VI) to less-toxic trivalent chromium (Cr(III)) in continuous long-term operation system over 4 months. Increasing the H2 pressure from 3 psig to 10 psig improved Cr(VI) removal from 87 % to 99 %, which occurred in parallel with over 95 % NO3[-] reduction to N2. Metagenomic analyses revealed the mechanisms of Cr(VI) bioreduction and highlighted the beneficial role of nitrate (NO3[-]) as the primary electron acceptor. For example, nitrite reductase NrfA could reduce Cr(VI), which lowered Cr(VI) caused oxidative stress. This research demonstrates the MBfR's effectiveness in reducing elevated levels of Cr(VI) and provides mechanistic understanding of the roles of denitrification in accelerating Cr(VI) reduction and detoxification.
Additional Links: PMID-40174456
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PubMed:
Citation:
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@article {pmid40174456,
year = {2025},
author = {Long, M and Zheng, CW and Zhou, C and Rittmann, BE},
title = {Mitigating chromate toxicity through concurrent denitrification in the H2-based membrane biofilm reactor.},
journal = {Journal of hazardous materials},
volume = {492},
number = {},
pages = {138073},
doi = {10.1016/j.jhazmat.2025.138073},
pmid = {40174456},
issn = {1873-3336},
abstract = {High concentrations of hexavalent chromium (Cr(VI)) in industrial wastewaters pose significant environmental and health hazards. Biotranformation is a viable means to lower Cr(VI) toxicity, but research to date has focused on wastewaters with low concentrations (e.g., 2-5 mg/L Cr(VI)). This study evaluated the dynamics of biosorption and biotransformation of higher-concentration Cr(VI) by biofilms in the H2-based membrane biofilm reactor (MBfR). While the biofilm in an MBfR receiving Cr(VI) alone had limited capacity to remove Cr(VI) and Cr(VI) removal ceased in 30 days, an autotrophic denitrifying biofilms achieved 99 % reduction of over 20 mg/L Cr(VI) to less-toxic trivalent chromium (Cr(III)) in continuous long-term operation system over 4 months. Increasing the H2 pressure from 3 psig to 10 psig improved Cr(VI) removal from 87 % to 99 %, which occurred in parallel with over 95 % NO3[-] reduction to N2. Metagenomic analyses revealed the mechanisms of Cr(VI) bioreduction and highlighted the beneficial role of nitrate (NO3[-]) as the primary electron acceptor. For example, nitrite reductase NrfA could reduce Cr(VI), which lowered Cr(VI) caused oxidative stress. This research demonstrates the MBfR's effectiveness in reducing elevated levels of Cr(VI) and provides mechanistic understanding of the roles of denitrification in accelerating Cr(VI) reduction and detoxification.},
}
RevDate: 2025-04-02
Synergizing carbon and phosphorus recovery from wastewater: Integrating biofilm-based phosphorus removal in high-rate activated sludge.
Water research, 280:123546 pii:S0043-1354(25)00459-2 [Epub ahead of print].
High-rate activated sludge operated at <2 days biomass age enhances carbon recovery from wastewater, but simultaneous biological recovery of phosphorus remains unachieved. Addressing the reported loss of phosphorus accumulating organisms (PAO) at such short biomass ages, this study investigated the integration of moving bed biofilms into high-rate activated sludge to enhance PAO retention. The results demonstrated sustained biofilm-based PAO activity and complete orthoP removal under short anaerobic-aerobic cycles with a hydraulic retention time of 2.7 h matching high-rate conditions. When combined with high-rate activated sludge in a sequencing batch reactor fed with acetate, complete orthoP removal was sustained. However, using synthetic wastewater promoted the growth of competing heterotrophic bacteria, reducing orthoP removal to 50-65 %. Biofilms served as a continuous source of PAO for the suspended biomass, which contributed to 46-55 % of the overall orthoP removal, even below 2 days biomass age. While acetate-fed microbial communities included known PAOs, using complex feed shifted the community toward less understood putative PAOs. Competition for acetate was likely compensated by a high fermentability of high-rate activated sludge, as PAO activity was maintained while reducing the acetate load in the feed from 20:1 to 5:1 g acetate⋅g P[-1]. P release and uptake rates were accurately described by the biomass-specific acetate loading rate and the depletion of intracellular polyphosphate, respectively, providing predictive relationships for process optimization. Imposing an anaerobic-aerobic regime enhanced the carbon recovery of high-rate activated sludge from about 37 to 60 %. Integrating biofilms enabled efficient phosphorus removal while maintaining carbon recovery rates of 41-53 %, highlighting the synergistic benefits of this approach.
Additional Links: PMID-40174422
Publisher:
PubMed:
Citation:
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@article {pmid40174422,
year = {2025},
author = {Sandeep, R and Madsen, JS and Marzocchi, U and Vergeynst, L},
title = {Synergizing carbon and phosphorus recovery from wastewater: Integrating biofilm-based phosphorus removal in high-rate activated sludge.},
journal = {Water research},
volume = {280},
number = {},
pages = {123546},
doi = {10.1016/j.watres.2025.123546},
pmid = {40174422},
issn = {1879-2448},
abstract = {High-rate activated sludge operated at <2 days biomass age enhances carbon recovery from wastewater, but simultaneous biological recovery of phosphorus remains unachieved. Addressing the reported loss of phosphorus accumulating organisms (PAO) at such short biomass ages, this study investigated the integration of moving bed biofilms into high-rate activated sludge to enhance PAO retention. The results demonstrated sustained biofilm-based PAO activity and complete orthoP removal under short anaerobic-aerobic cycles with a hydraulic retention time of 2.7 h matching high-rate conditions. When combined with high-rate activated sludge in a sequencing batch reactor fed with acetate, complete orthoP removal was sustained. However, using synthetic wastewater promoted the growth of competing heterotrophic bacteria, reducing orthoP removal to 50-65 %. Biofilms served as a continuous source of PAO for the suspended biomass, which contributed to 46-55 % of the overall orthoP removal, even below 2 days biomass age. While acetate-fed microbial communities included known PAOs, using complex feed shifted the community toward less understood putative PAOs. Competition for acetate was likely compensated by a high fermentability of high-rate activated sludge, as PAO activity was maintained while reducing the acetate load in the feed from 20:1 to 5:1 g acetate⋅g P[-1]. P release and uptake rates were accurately described by the biomass-specific acetate loading rate and the depletion of intracellular polyphosphate, respectively, providing predictive relationships for process optimization. Imposing an anaerobic-aerobic regime enhanced the carbon recovery of high-rate activated sludge from about 37 to 60 %. Integrating biofilms enabled efficient phosphorus removal while maintaining carbon recovery rates of 41-53 %, highlighting the synergistic benefits of this approach.},
}
RevDate: 2025-04-02
Candida albicans biofilm extracellular vesicles deliver candidalysin to epithelial cell membranes and induce host cell responses.
Infection and immunity [Epub ahead of print].
Extracellular vesicles (EVs) are heterogeneous particles encapsulated with a phospholipid bilayer membrane. EVs have evolved diverse biological functions, serving mainly as prominent mediators and regulators of cell-cell communication. This study investigated whether candidalysin, a key virulence factor in Candida albicans infections, is present within EVs derived from C. albicans biofilms and retains activity by inducing host immune responses. We found that biofilm EVs contain candidalysin and can permeabilize planar lipid bilayer membranes in a dose-dependent manner. However, biofilm EVs were unable to damage oral epithelial cells (OECs) but were able to induce cytokine responses. Notably, EVs obtained from biofilms cultured for 24 h and 48 h exhibited differences in cargo composition and their ability to activate OECs. This study highlights the potential of biofilm EVs as a toxin delivery system during C. albicans infection and identifies temporal differences in the ability of EVs to activate epithelial cells.
Additional Links: PMID-40172491
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PubMed:
Citation:
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@article {pmid40172491,
year = {2025},
author = {Lee, S and Tsavou, A and Zarnowski, R and Pforte, R and Allert, S and Krüger, T and Kniemeyer, O and Brakhage, AA and Bui, TTT and Andes, DR and Richardson, JP and Hube, B and Naglik, JR},
title = {Candida albicans biofilm extracellular vesicles deliver candidalysin to epithelial cell membranes and induce host cell responses.},
journal = {Infection and immunity},
volume = {},
number = {},
pages = {e0040424},
doi = {10.1128/iai.00404-24},
pmid = {40172491},
issn = {1098-5522},
abstract = {Extracellular vesicles (EVs) are heterogeneous particles encapsulated with a phospholipid bilayer membrane. EVs have evolved diverse biological functions, serving mainly as prominent mediators and regulators of cell-cell communication. This study investigated whether candidalysin, a key virulence factor in Candida albicans infections, is present within EVs derived from C. albicans biofilms and retains activity by inducing host immune responses. We found that biofilm EVs contain candidalysin and can permeabilize planar lipid bilayer membranes in a dose-dependent manner. However, biofilm EVs were unable to damage oral epithelial cells (OECs) but were able to induce cytokine responses. Notably, EVs obtained from biofilms cultured for 24 h and 48 h exhibited differences in cargo composition and their ability to activate OECs. This study highlights the potential of biofilm EVs as a toxin delivery system during C. albicans infection and identifies temporal differences in the ability of EVs to activate epithelial cells.},
}
RevDate: 2025-04-03
CmpDate: 2025-04-02
Comparison between biliary plastic stents with and without application of silver nanoparticles: an in-vitro study of the biofilm formation.
Acta cirurgica brasileira, 40:e402825.
PURPOSE: Plastic biliary stents are a cost-effective treatment for biliary obstruction. Unfortunately, they have low patency, related to intraluminal biofilm formation. Silver nanoparticles (AgNPs) have been increasingly used in biomedicine because of its antibacterial properties. This study aimed to compare biofilm formation on stents with and without silver nanoparticle coatings when in contact with different bacterial culture medium.
METHODS: Different types of silver coatings were tested on plastic biliary stents. Two groups of stents were analyzed: one group with various types of silver nanoparticle coatings, and a negative control group with no coating. The stents were placed in different bacterial culture media and assessed for biofilm formation. Analysis was performed using confocal microscopy and direct colony-forming unit (CFU/cm2).
RESULTS: Quantitative analysis showed promising results with C16 coating, as Escherichia coli ATCC and Pseudomonas aeruginosa ATCC exhibited reduced growth in the AgNP-coated group (p < 0.05). However, when mixed samples, including clinical strains and Staphylococcus aureus, were tested, the AgNP coating did not inhibit bacterial growth.
CONCLUSION: AgNP-coated stents are effective against certain strains, such as E. coli ATCC and P. aeruginosa. Further research is needed to explore potential improvements in the coating mechanism.
Additional Links: PMID-40172368
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Citation:
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@article {pmid40172368,
year = {2025},
author = {Flumignan, VK and Sircili, MP and Franzolin, MR and Tavassi, AMC and Germano, LG and Souza, AVDS and Silva, NF and Fukumasu, NK and Anjos, RMD and Otoch, JP and Artifon, ELA},
title = {Comparison between biliary plastic stents with and without application of silver nanoparticles: an in-vitro study of the biofilm formation.},
journal = {Acta cirurgica brasileira},
volume = {40},
number = {},
pages = {e402825},
pmid = {40172368},
issn = {1678-2674},
mesh = {*Biofilms/drug effects/growth & development ; *Silver/pharmacology ; *Metal Nanoparticles ; *Pseudomonas aeruginosa/drug effects ; *Stents/microbiology ; *Escherichia coli/drug effects/growth & development ; *Staphylococcus aureus/drug effects ; Plastics/chemistry/pharmacology ; Coated Materials, Biocompatible/pharmacology/chemistry ; Anti-Bacterial Agents/pharmacology ; Microscopy, Confocal ; Humans ; Reproducibility of Results ; Materials Testing ; Colony Count, Microbial ; },
abstract = {PURPOSE: Plastic biliary stents are a cost-effective treatment for biliary obstruction. Unfortunately, they have low patency, related to intraluminal biofilm formation. Silver nanoparticles (AgNPs) have been increasingly used in biomedicine because of its antibacterial properties. This study aimed to compare biofilm formation on stents with and without silver nanoparticle coatings when in contact with different bacterial culture medium.
METHODS: Different types of silver coatings were tested on plastic biliary stents. Two groups of stents were analyzed: one group with various types of silver nanoparticle coatings, and a negative control group with no coating. The stents were placed in different bacterial culture media and assessed for biofilm formation. Analysis was performed using confocal microscopy and direct colony-forming unit (CFU/cm2).
RESULTS: Quantitative analysis showed promising results with C16 coating, as Escherichia coli ATCC and Pseudomonas aeruginosa ATCC exhibited reduced growth in the AgNP-coated group (p < 0.05). However, when mixed samples, including clinical strains and Staphylococcus aureus, were tested, the AgNP coating did not inhibit bacterial growth.
CONCLUSION: AgNP-coated stents are effective against certain strains, such as E. coli ATCC and P. aeruginosa. Further research is needed to explore potential improvements in the coating mechanism.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Silver/pharmacology
*Metal Nanoparticles
*Pseudomonas aeruginosa/drug effects
*Stents/microbiology
*Escherichia coli/drug effects/growth & development
*Staphylococcus aureus/drug effects
Plastics/chemistry/pharmacology
Coated Materials, Biocompatible/pharmacology/chemistry
Anti-Bacterial Agents/pharmacology
Microscopy, Confocal
Humans
Reproducibility of Results
Materials Testing
Colony Count, Microbial
RevDate: 2025-04-04
CmpDate: 2025-04-02
Linalool as a potential agent for inhibiting Escherichia coli biofilm formation and exopolysaccharide production.
BMC veterinary research, 21(1):235.
Escherichia coli (E. coli) is one of the most common pathogens causing endometritis in dairy cows. The presence of genes encoding extended-spectrum β-lactamase (ESBL) and biofilm formation are important factors contributing to bacterial resistance, which poses a significant challenge to the treatment of endometritis in dairy cows. Essential oils containing linalool have been shown to improve the cure rate of bovine endometritis, but whether linalool can inhibit E. coli biofilm has not yet been reported. We proposed to ascertain the linalool implications on the development of E. coli biofilm and its extracellular polysaccharides, as well as to assess the impacts of linalool on E. coli in both planktonic and biofilm states. We discovered that the minimum biofilm inhibitory concentrations (MBICs) of linalool against E. coli were twice as high as the minimum inhibitory concentrations. Linalool exhibited a strong bactericidal effect on clinical E. coli strain producing ESBL and forming strong biofilm, regardless of whether they were in a planktonic or biofilm condition. Linalool suppressed the biofilm development in a way that was dependent on the dosage, with an MBIC 4 µL/mL. This was verified by the use of crystal violet test and scanning electron microscopy. Moreover, the CCK-8 assay and confocal laser scanning microscopy (CLSM) manifested significant reductions in live bacteria within the biofilm. The concentrations of extracellular polymeric compounds in the E. coli biofilm were also reduced. Furthermore, CLSM and RT-qPCR analysis confirmed that linalool (2 µL/mL) significantly suppressed exopolysaccharide (EPS) and the pgaABCD gene expression, regulating an essential exopolysaccharide expression in biofilm formation. These findings revealed that linalool effectively suppressed viable bacteria, EPS production, and E. coli biofilm formation, providing a theoretical foundation for alternative antibiotic therapy in endometritis in dairy cows and as a potential agent for preventing E. coli biofilm-related infections.
Additional Links: PMID-40169959
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Citation:
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@article {pmid40169959,
year = {2025},
author = {Wang, L and Wang, J and Zhang, K and Zhang, J and Cui, D and Wang, J and Ji, P and Wei, Y and Li, J},
title = {Linalool as a potential agent for inhibiting Escherichia coli biofilm formation and exopolysaccharide production.},
journal = {BMC veterinary research},
volume = {21},
number = {1},
pages = {235},
pmid = {40169959},
issn = {1746-6148},
support = {No. 31902316//National Natural Science Foundation of China/ ; 2022YFD1801101-4//National Key Research and Development Program of China/ ; CAAS-ZDRW202111//Major scientific research tasks of the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences/ ; CARS-36-04//China Agriculture Research System/ ; CAAS -ASTIP-2015-LIHPS//the Innovation Project of Traditional Chinese Veterinary Medicine and Clinical Science/ ; },
mesh = {*Biofilms/drug effects ; *Acyclic Monoterpenes/pharmacology ; *Escherichia coli/drug effects ; *Polysaccharides, Bacterial ; *Monoterpenes/pharmacology ; *Microbial Sensitivity Tests ; Anti-Bacterial Agents/pharmacology ; Animals ; Female ; },
abstract = {Escherichia coli (E. coli) is one of the most common pathogens causing endometritis in dairy cows. The presence of genes encoding extended-spectrum β-lactamase (ESBL) and biofilm formation are important factors contributing to bacterial resistance, which poses a significant challenge to the treatment of endometritis in dairy cows. Essential oils containing linalool have been shown to improve the cure rate of bovine endometritis, but whether linalool can inhibit E. coli biofilm has not yet been reported. We proposed to ascertain the linalool implications on the development of E. coli biofilm and its extracellular polysaccharides, as well as to assess the impacts of linalool on E. coli in both planktonic and biofilm states. We discovered that the minimum biofilm inhibitory concentrations (MBICs) of linalool against E. coli were twice as high as the minimum inhibitory concentrations. Linalool exhibited a strong bactericidal effect on clinical E. coli strain producing ESBL and forming strong biofilm, regardless of whether they were in a planktonic or biofilm condition. Linalool suppressed the biofilm development in a way that was dependent on the dosage, with an MBIC 4 µL/mL. This was verified by the use of crystal violet test and scanning electron microscopy. Moreover, the CCK-8 assay and confocal laser scanning microscopy (CLSM) manifested significant reductions in live bacteria within the biofilm. The concentrations of extracellular polymeric compounds in the E. coli biofilm were also reduced. Furthermore, CLSM and RT-qPCR analysis confirmed that linalool (2 µL/mL) significantly suppressed exopolysaccharide (EPS) and the pgaABCD gene expression, regulating an essential exopolysaccharide expression in biofilm formation. These findings revealed that linalool effectively suppressed viable bacteria, EPS production, and E. coli biofilm formation, providing a theoretical foundation for alternative antibiotic therapy in endometritis in dairy cows and as a potential agent for preventing E. coli biofilm-related infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
*Acyclic Monoterpenes/pharmacology
*Escherichia coli/drug effects
*Polysaccharides, Bacterial
*Monoterpenes/pharmacology
*Microbial Sensitivity Tests
Anti-Bacterial Agents/pharmacology
Animals
Female
RevDate: 2025-04-04
Repurposing antimicrobials with ultrasound-triggered nanoscale systems for targeted biofilm drug delivery.
npj antimicrobials and resistance, 3(1):22.
Chronic infections represent a major clinical challenge due to the enhanced antimicrobial tolerance of biofilm-dwelling bacteria. To address this challenge, an ultrasound-responsive nanoscale drug delivery platform (nanodroplets) is presented in this work, loaded with four different antimicrobial agents, capable of simultaneous biofilm disruption and targeted antimicrobial delivery. When loaded, a robust protective effect against clinically-derived MRSA and ESBL Gram-positive and Gram-negative planktonic isolates was shown in vitro. Upon application of therapeutic ultrasound, an average 7.6-fold, 44.4-fold, and 25.5-fold reduction was observed in the antibiotic concentrations compared to free drug required to reach the MBC, MBEC and complete persister eradication levels, respectively. Nanodroplets substantially altered subcellular distribution of encapsulated antimicrobials, enhancing accumulation of antimicrobials by 11.1-fold within the biofilm-residing bacteria's cytoplasm compared to treatment with unencapsulated drugs. These findings illustrate the potential of this multifunctional platform to overcome the critical penetration and localization limitations of antimicrobials within biofilms, opening potential new avenues in the treatment of chronic clinical infections.
Additional Links: PMID-40169915
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@article {pmid40169915,
year = {2025},
author = {Choi, V and Carugo, D and Stride, E},
title = {Repurposing antimicrobials with ultrasound-triggered nanoscale systems for targeted biofilm drug delivery.},
journal = {npj antimicrobials and resistance},
volume = {3},
number = {1},
pages = {22},
pmid = {40169915},
issn = {2731-8745},
support = {EP/V026623/1//Engineering and Physical Sciences Research Council/ ; EP/V026623/1//Engineering and Physical Sciences Research Council/ ; EP/V026623/1//Engineering and Physical Sciences Research Council/ ; },
abstract = {Chronic infections represent a major clinical challenge due to the enhanced antimicrobial tolerance of biofilm-dwelling bacteria. To address this challenge, an ultrasound-responsive nanoscale drug delivery platform (nanodroplets) is presented in this work, loaded with four different antimicrobial agents, capable of simultaneous biofilm disruption and targeted antimicrobial delivery. When loaded, a robust protective effect against clinically-derived MRSA and ESBL Gram-positive and Gram-negative planktonic isolates was shown in vitro. Upon application of therapeutic ultrasound, an average 7.6-fold, 44.4-fold, and 25.5-fold reduction was observed in the antibiotic concentrations compared to free drug required to reach the MBC, MBEC and complete persister eradication levels, respectively. Nanodroplets substantially altered subcellular distribution of encapsulated antimicrobials, enhancing accumulation of antimicrobials by 11.1-fold within the biofilm-residing bacteria's cytoplasm compared to treatment with unencapsulated drugs. These findings illustrate the potential of this multifunctional platform to overcome the critical penetration and localization limitations of antimicrobials within biofilms, opening potential new avenues in the treatment of chronic clinical infections.},
}
RevDate: 2025-04-02
Ferrous sulfate/carboxymethyl chitosan agar-based film triggers ferroptosis in Pseudomonas aeruginosa planktonic and biofilm cells for antibacterial preservation of fruits and vegetables.
International journal of biological macromolecules, 308(Pt 3):142697 pii:S0141-8130(25)03249-0 [Epub ahead of print].
The ferrous sulfate (FeSO4)-based mechanism causing ferroptosis-like death in Pseudomonas aeruginosa was investigated. FeSO4 triggered ferroptosis in P. aeruginosa planktonic cells, decreased the ratio of glutathione to oxidized glutathione, and resulted in the increase of reactive oxygen species and lipid peroxidation, damaging the integrity of the cell membrane. In addition, FeSO4 prevented P. aeruginosa from forming biofilms on the surface of stainless steel, glass, and high-density polyethylene. Transcriptome analyses indicated that there were 412 up-regulated genes and 782 down-regulated genes following FeSO4 treatment. FeSO4 increased the cross-linking density of a carboxymethyl chitosan (CMCS) agar-based film, reducing its water solubility, swelling degree, water vapor permeability, and oxygen permeability. Finally, FeSO4@CMCS agar-based film showed potential antibacterial ability against the growth of P. aeruginosa in grapes, purple kale, and cherry tomatoes during storage.
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@article {pmid40169056,
year = {2025},
author = {Sun, J and Shen, HL and Pan, JN and Yu, T and Zhou, WW},
title = {Ferrous sulfate/carboxymethyl chitosan agar-based film triggers ferroptosis in Pseudomonas aeruginosa planktonic and biofilm cells for antibacterial preservation of fruits and vegetables.},
journal = {International journal of biological macromolecules},
volume = {308},
number = {Pt 3},
pages = {142697},
doi = {10.1016/j.ijbiomac.2025.142697},
pmid = {40169056},
issn = {1879-0003},
abstract = {The ferrous sulfate (FeSO4)-based mechanism causing ferroptosis-like death in Pseudomonas aeruginosa was investigated. FeSO4 triggered ferroptosis in P. aeruginosa planktonic cells, decreased the ratio of glutathione to oxidized glutathione, and resulted in the increase of reactive oxygen species and lipid peroxidation, damaging the integrity of the cell membrane. In addition, FeSO4 prevented P. aeruginosa from forming biofilms on the surface of stainless steel, glass, and high-density polyethylene. Transcriptome analyses indicated that there were 412 up-regulated genes and 782 down-regulated genes following FeSO4 treatment. FeSO4 increased the cross-linking density of a carboxymethyl chitosan (CMCS) agar-based film, reducing its water solubility, swelling degree, water vapor permeability, and oxygen permeability. Finally, FeSO4@CMCS agar-based film showed potential antibacterial ability against the growth of P. aeruginosa in grapes, purple kale, and cherry tomatoes during storage.},
}
RevDate: 2025-04-01
Long-term impacts of free chlorine and monochloramine on the development of drinking water biofilm.
Water research, 281:123566 pii:S0043-1354(25)00479-8 [Epub ahead of print].
Biofilm formation in drinking water distribution systems is primarily managed by disinfectants such as free chlorine (FC) and monochloramine (MC). However, there is limited understanding of their long-term and dynamic effects on biofilm development. To address this, a 56-week study was conducted to comprehensively assess biofilm development in terms of microbial quantity and community under different disinfection regimes: no chlorine (NC), FC (0.1 mg/L), and MC (0.4 mg/L). The results showed that both FC and MC significantly inhibited biofilm growth compared to the NC condition while shaping distinct biofilm communities. Notably, FC drastically reduced biofilm biomass and community diversity, resulting in a more uniform biofilm community predominantly composed of Proteobacteria (e.g., Rhizobacter spp., Pseudomonas spp., and Hyphomicrobium spp.), indicating stronger selection pressures on the microbial population. In contrast, though MC effectively reduced the biofilm biomass to a level comparable to that of FC, it maintained a high diversity comparable to that of NC (dominated by Sphingobium spp. and Nocardioides spp.), reflecting weaker selection pressure on bacterial community. Temporally, biofilm communities under all conditions started from nearly identical states. From week-19 and week-36 onwards, deterministic processes predominantly governed biofilm formation under FC and NC conditions, signifying that these biofilms reached a stable state. Differently, under MC condition, the community assembly was continually influenced by stochastic processes, with the biofilm not achieving stability until week-56. Overall, this study provides valuable insights into the long-term dynamics of biofilm development and evidenced that FC is better than MC in controlling biofilm formation, particularly from the community diversity perspective. This challenges classical views that MC is more effective than FC in penetrating and controlling biofilm, which may change the popularity of MC as a disinfectant in water utilities.
Additional Links: PMID-40168779
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@article {pmid40168779,
year = {2025},
author = {Chen, L and Shi, H and Medema, G and van der Meer, W and Liu, G},
title = {Long-term impacts of free chlorine and monochloramine on the development of drinking water biofilm.},
journal = {Water research},
volume = {281},
number = {},
pages = {123566},
doi = {10.1016/j.watres.2025.123566},
pmid = {40168779},
issn = {1879-2448},
abstract = {Biofilm formation in drinking water distribution systems is primarily managed by disinfectants such as free chlorine (FC) and monochloramine (MC). However, there is limited understanding of their long-term and dynamic effects on biofilm development. To address this, a 56-week study was conducted to comprehensively assess biofilm development in terms of microbial quantity and community under different disinfection regimes: no chlorine (NC), FC (0.1 mg/L), and MC (0.4 mg/L). The results showed that both FC and MC significantly inhibited biofilm growth compared to the NC condition while shaping distinct biofilm communities. Notably, FC drastically reduced biofilm biomass and community diversity, resulting in a more uniform biofilm community predominantly composed of Proteobacteria (e.g., Rhizobacter spp., Pseudomonas spp., and Hyphomicrobium spp.), indicating stronger selection pressures on the microbial population. In contrast, though MC effectively reduced the biofilm biomass to a level comparable to that of FC, it maintained a high diversity comparable to that of NC (dominated by Sphingobium spp. and Nocardioides spp.), reflecting weaker selection pressure on bacterial community. Temporally, biofilm communities under all conditions started from nearly identical states. From week-19 and week-36 onwards, deterministic processes predominantly governed biofilm formation under FC and NC conditions, signifying that these biofilms reached a stable state. Differently, under MC condition, the community assembly was continually influenced by stochastic processes, with the biofilm not achieving stability until week-56. Overall, this study provides valuable insights into the long-term dynamics of biofilm development and evidenced that FC is better than MC in controlling biofilm formation, particularly from the community diversity perspective. This challenges classical views that MC is more effective than FC in penetrating and controlling biofilm, which may change the popularity of MC as a disinfectant in water utilities.},
}
RevDate: 2025-04-01
Trans-cinnamaldehyde nanoemulsion reduces Salmonella Enteritidis biofilm on steel and plastic surfaces and downregulates expression of biofilm associated genes.
Poultry science, 104(5):105086 pii:S0032-5791(25)00325-6 [Epub ahead of print].
Salmonella Enteritidis is a major poultry-associated foodborne pathogen that can form sanitizer-tolerant biofilms on various surfaces. The biofilm-forming capability of S. Enteritidis facilitates its survival on farm and food processing equipment. Conventional sanitization methods are not completely effective in killing S. Enteritidis biofilms. This study investigated the efficacy of a Generally Recognized as Safe phytochemical Trans-cinnamaldehyde (TC), and in its nanoemulsion form (TCNE), for inhibiting S. Enteritidis biofilm formation and inactivating mature biofilms developed on polystyrene and stainless-steel surfaces. Moreover, the effect of TC on Salmonella genes critical for biofilm formation was studied. TCNE was prepared using a high energy sonication method with Tween 80. For biofilm inhibition assay, S. Enteritidis was allowed to form biofilms either in the presence or absence of sub-inhibitory concentration (SIC; 0.01 %) of TCNE at 25°C and the biofilm formed was quantified at 24-h intervals for 48 h. For the inactivation assay, S. Enteritidis biofilms developed at 25°C for 48 h were exposed to TCNE (0.5, 1 %) for 1, 5, and 15 min, and surviving S. Enteritidis in the biofilm were enumerated. SIC of TCNE inhibited S. Enteritidis biofilm by 45 % on polystyrene and 75 % on steel surface after 48 h at 25°C compared to control (P < 0.05). All TCNE treatments rapidly inactivated S. Enteritidis mature biofilm on polystyrene and steel surfaces (P < 0.05). The lower concentration of TCNE (0.5 %) reduced S. Enteritidis counts by 1.5 log CFU/ml as early as 1 min of exposure on both polystyrene and stainless-steel surfaces. After 15 min of exposure, TCNE at concentration of 0.5 or 1 % reduced S. Enteritidis count significantly by 4.5 log CFU or 6 log CFU/ml on polystyrene or stainless-steel surfaces. TC downregulated the expression of S. Enteritidis genes (hilA, hilC, flhD, csgA, csgD, sdiA) responsible for biofilm formation (P < 0.05). Results suggest that TCNE has potential as a natural disinfectant for controlling S. Enteritidis biofilms on common farm and food processing surfaces, such as plastic and steel.
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@article {pmid40168703,
year = {2025},
author = {Shah, T and Zhu, C and Shah, C and Upadhyaya, I and Upadhyay, A},
title = {Trans-cinnamaldehyde nanoemulsion reduces Salmonella Enteritidis biofilm on steel and plastic surfaces and downregulates expression of biofilm associated genes.},
journal = {Poultry science},
volume = {104},
number = {5},
pages = {105086},
doi = {10.1016/j.psj.2025.105086},
pmid = {40168703},
issn = {1525-3171},
abstract = {Salmonella Enteritidis is a major poultry-associated foodborne pathogen that can form sanitizer-tolerant biofilms on various surfaces. The biofilm-forming capability of S. Enteritidis facilitates its survival on farm and food processing equipment. Conventional sanitization methods are not completely effective in killing S. Enteritidis biofilms. This study investigated the efficacy of a Generally Recognized as Safe phytochemical Trans-cinnamaldehyde (TC), and in its nanoemulsion form (TCNE), for inhibiting S. Enteritidis biofilm formation and inactivating mature biofilms developed on polystyrene and stainless-steel surfaces. Moreover, the effect of TC on Salmonella genes critical for biofilm formation was studied. TCNE was prepared using a high energy sonication method with Tween 80. For biofilm inhibition assay, S. Enteritidis was allowed to form biofilms either in the presence or absence of sub-inhibitory concentration (SIC; 0.01 %) of TCNE at 25°C and the biofilm formed was quantified at 24-h intervals for 48 h. For the inactivation assay, S. Enteritidis biofilms developed at 25°C for 48 h were exposed to TCNE (0.5, 1 %) for 1, 5, and 15 min, and surviving S. Enteritidis in the biofilm were enumerated. SIC of TCNE inhibited S. Enteritidis biofilm by 45 % on polystyrene and 75 % on steel surface after 48 h at 25°C compared to control (P < 0.05). All TCNE treatments rapidly inactivated S. Enteritidis mature biofilm on polystyrene and steel surfaces (P < 0.05). The lower concentration of TCNE (0.5 %) reduced S. Enteritidis counts by 1.5 log CFU/ml as early as 1 min of exposure on both polystyrene and stainless-steel surfaces. After 15 min of exposure, TCNE at concentration of 0.5 or 1 % reduced S. Enteritidis count significantly by 4.5 log CFU or 6 log CFU/ml on polystyrene or stainless-steel surfaces. TC downregulated the expression of S. Enteritidis genes (hilA, hilC, flhD, csgA, csgD, sdiA) responsible for biofilm formation (P < 0.05). Results suggest that TCNE has potential as a natural disinfectant for controlling S. Enteritidis biofilms on common farm and food processing surfaces, such as plastic and steel.},
}
RevDate: 2025-04-03
CmpDate: 2025-04-01
An update on hybrid membrane aerated biofilm reactor technology.
Water environment research : a research publication of the Water Environment Federation, 97(4):e70065.
The hybrid membrane aerated biofilm reactor (MABR) process combines the advantages of the counter-diffusional biofilm and bubbleless aeration of the MABR with the good bioflocculation and carbon processing capabilities of suspended growth processes. These features result in a process with reduced physical footprint, excellent biological nutrient removal capabilities, potentially reduced greenhouse gas (GHG) emissions, and significantly reduced energy requirements that can be easily retrofitted into existing suspended growth processes. Commercially introduced in the mid-2010s, the demonstrated advantages of the hybrid MABR process are resulting in rapid full-scale adoption. Meanwhile, researchers are advancing knowledge on the hybrid MABR process and revealing potential opportunities for improved performance. This paper summarizes recent findings and identifies areas that can be further developed to advance hybrid MABR process evaluation and development. PRACTITIONER POINTS: Rapid application of the hybrid MABR process is leading to significant new developments that can enhance performance. Sizing MABR for nearly complete nitrification allows significant downsizing of the bioreactor, coupled with excellent nitrogen removal and energy savings. Online exhaust gas % O2 and bulk ammonia concentration can be used to create a soft sensor characterizing changes in biofilm thickness enabling biofilm control to optimize performance. Further advancements through improved aeration control, configurations to achieve partial nitritation and annammox, and achieving granulation offer further significant advances.
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@article {pmid40166967,
year = {2025},
author = {He, H and Carlson, AL and Wagner, B and Yang, C and Cao, Y and Uzair, MD and Daigger, GT},
title = {An update on hybrid membrane aerated biofilm reactor technology.},
journal = {Water environment research : a research publication of the Water Environment Federation},
volume = {97},
number = {4},
pages = {e70065},
pmid = {40166967},
issn = {1554-7531},
mesh = {*Biofilms ; *Bioreactors ; Membranes, Artificial ; Waste Disposal, Fluid/methods ; },
abstract = {The hybrid membrane aerated biofilm reactor (MABR) process combines the advantages of the counter-diffusional biofilm and bubbleless aeration of the MABR with the good bioflocculation and carbon processing capabilities of suspended growth processes. These features result in a process with reduced physical footprint, excellent biological nutrient removal capabilities, potentially reduced greenhouse gas (GHG) emissions, and significantly reduced energy requirements that can be easily retrofitted into existing suspended growth processes. Commercially introduced in the mid-2010s, the demonstrated advantages of the hybrid MABR process are resulting in rapid full-scale adoption. Meanwhile, researchers are advancing knowledge on the hybrid MABR process and revealing potential opportunities for improved performance. This paper summarizes recent findings and identifies areas that can be further developed to advance hybrid MABR process evaluation and development. PRACTITIONER POINTS: Rapid application of the hybrid MABR process is leading to significant new developments that can enhance performance. Sizing MABR for nearly complete nitrification allows significant downsizing of the bioreactor, coupled with excellent nitrogen removal and energy savings. Online exhaust gas % O2 and bulk ammonia concentration can be used to create a soft sensor characterizing changes in biofilm thickness enabling biofilm control to optimize performance. Further advancements through improved aeration control, configurations to achieve partial nitritation and annammox, and achieving granulation offer further significant advances.},
}
MeSH Terms:
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*Biofilms
*Bioreactors
Membranes, Artificial
Waste Disposal, Fluid/methods
RevDate: 2025-04-01
CmpDate: 2025-04-01
Comparison of Biofilm Accumulation on Conventional and CAD/CAM Orthodontic Band Alloys (In Vivo) and Subsequent Enamel Demineralization (Ex Vivo).
Journal of biomedical materials research. Part B, Applied biomaterials, 113(4):e35573.
Biofilm accumulation can lead to enamel decalcification, gingivitis, and periodontal disease. The objective of this study was to compare the accumulation of biofilm under in vivo conditions and consequent ex vivo acid production and enamel demineralization around the material used for "off-the-shelf" conventional and CAD/CAM orthodontics bands. The study design required both in vivo and in vitro approaches. An experimental model was utilized to combine the exposure of an in vivo formed biofilm to in vitro cariogenic conditions to achieve the objective. Twenty-one consenting participants took part in this study. Participants wore custom intraoral appliances containing six bovine enamel discs (three on each maxillary arch) for 48 h. Tiles made from conventional stainless steel bands (SS tiles group), CAD/CAM tiles made of Sintron cobalt-chromium (CoCr) sinter metal (Sintron tiles group), and no tile (control group) were randomly assigned to disc positions such that each appliance contained two tiles from each group (126 tiles in total). Participants immersed the appliances in sucrose solution (10% w/v) for 5 min, five times per day. After 48 h, appliances were removed, the discs were recovered, and incubated in glucose (1%)/PBS for 24 h. The pH of the glucose/PBS measured the relative acid produced by the accumulated biofilm, and calcium released from the discs quantified demineralization. Disclosing dye was used to stain and delineate the biofilm before each disc was digitally photographed and analyzed to determine the biofilm coverage. The mean biofilm coverage ranged between 0% and 86% (mean 9.63%) of disc surface area, but there was no difference in biofilm coverage between tile groups or between tile positions. Significantly less acid was generated by the control discs biofilms (mean pH 5.06) than either SS or CAD/CAM tiles biofilms (pH 4.72 and 4.84, respectively), which were not different from one another. Position on the appliance did not affect acid production. Control discs experienced greater demineralization (mean 136 μg Ca/disc) than either the SS (122 μg Ca/disc) or Sintron (114 μg Ca/disc) tile groups, which suffered equivalent demineralization. Position on the appliances did not influence demineralization. The study provides no evidence that CAD/CAM-designed components of orthodontic bands are more beneficial than conventional bands in terms of biofilm accumulation and consequent caries risk.
Additional Links: PMID-40166962
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@article {pmid40166962,
year = {2025},
author = {Horsnell, A and Farella, M and Tompkins, G and van Vuuren, WJ},
title = {Comparison of Biofilm Accumulation on Conventional and CAD/CAM Orthodontic Band Alloys (In Vivo) and Subsequent Enamel Demineralization (Ex Vivo).},
journal = {Journal of biomedical materials research. Part B, Applied biomaterials},
volume = {113},
number = {4},
pages = {e35573},
doi = {10.1002/jbm.b.35573},
pmid = {40166962},
issn = {1552-4981},
support = {//Division of Health Sciences, University of Otago/ ; },
mesh = {*Biofilms ; Animals ; Humans ; Cattle ; Adult ; Male ; *Tooth Demineralization ; *Dental Enamel/metabolism/chemistry/microbiology ; Female ; Computer-Aided Design ; },
abstract = {Biofilm accumulation can lead to enamel decalcification, gingivitis, and periodontal disease. The objective of this study was to compare the accumulation of biofilm under in vivo conditions and consequent ex vivo acid production and enamel demineralization around the material used for "off-the-shelf" conventional and CAD/CAM orthodontics bands. The study design required both in vivo and in vitro approaches. An experimental model was utilized to combine the exposure of an in vivo formed biofilm to in vitro cariogenic conditions to achieve the objective. Twenty-one consenting participants took part in this study. Participants wore custom intraoral appliances containing six bovine enamel discs (three on each maxillary arch) for 48 h. Tiles made from conventional stainless steel bands (SS tiles group), CAD/CAM tiles made of Sintron cobalt-chromium (CoCr) sinter metal (Sintron tiles group), and no tile (control group) were randomly assigned to disc positions such that each appliance contained two tiles from each group (126 tiles in total). Participants immersed the appliances in sucrose solution (10% w/v) for 5 min, five times per day. After 48 h, appliances were removed, the discs were recovered, and incubated in glucose (1%)/PBS for 24 h. The pH of the glucose/PBS measured the relative acid produced by the accumulated biofilm, and calcium released from the discs quantified demineralization. Disclosing dye was used to stain and delineate the biofilm before each disc was digitally photographed and analyzed to determine the biofilm coverage. The mean biofilm coverage ranged between 0% and 86% (mean 9.63%) of disc surface area, but there was no difference in biofilm coverage between tile groups or between tile positions. Significantly less acid was generated by the control discs biofilms (mean pH 5.06) than either SS or CAD/CAM tiles biofilms (pH 4.72 and 4.84, respectively), which were not different from one another. Position on the appliance did not affect acid production. Control discs experienced greater demineralization (mean 136 μg Ca/disc) than either the SS (122 μg Ca/disc) or Sintron (114 μg Ca/disc) tile groups, which suffered equivalent demineralization. Position on the appliances did not influence demineralization. The study provides no evidence that CAD/CAM-designed components of orthodontic bands are more beneficial than conventional bands in terms of biofilm accumulation and consequent caries risk.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms
Animals
Humans
Cattle
Adult
Male
*Tooth Demineralization
*Dental Enamel/metabolism/chemistry/microbiology
Female
Computer-Aided Design
RevDate: 2025-04-01
A class of secreted retropepsin-like enzymes is required for osmotic stress tolerance, antibiotic resistance and biofilm formation in Pseudomonas aeruginosa.
bioRxiv : the preprint server for biology pii:2025.03.18.643919.
UNLABELLED: Proteases regulate important biological functions. Here we present the structural and functional characterization of three previously uncharacterized aspartic proteases in Pseudomonas aeruginosa . We show that these proteases have structural hallmarks of retropepsin peptidases and play redundant roles for cell survival under hypoosmotic stress conditions. Consequently, we named them retropepsin-like osmotic stress tolerance peptidases (Rlo). Our research shows that while Rlo proteases are homologous to RimB, an aspartic peptidase involved in rhizosphere colonization and plant infection, they contain N-terminal signal peptides and perform distinct biological functions. Mutants lacking all three secreted Rlo peptidases show defects in antibiotic resistance, biofilm formation, and cell morphology. These defects are rescued by mutations in the inactive transglutaminase transmembrane protein RloB and the cytoplasmic ATP-grasp protein RloC, two previously uncharacterized genes in the same operon as one of the Rlo proteases. These studies identify Rlo proteases and rlo operon products as critical factors in clinically relevant processes, making them appealing targets for therapeutic strategies against Pseudomonas infections.
IMPORTANCE: Bacterial infections have become harder to treat due to the ability of pathogens to adapt to different environments and the rise of antimicrobial resistance. This has led to longer illnesses, increased medical costs, and higher mortality rates. The opportunistic pathogen Pseudomonas aeruginosa is particularly problematic because of its inherent resistance to many antibiotics and its capacity to form biofilms, structures that allow bacteria to withstand hostile conditions. Our study uncovers a new class of retropepsin-like proteases in P. aeruginosa that are required for biofilm formation and bacterial survival upon stress conditions, including antibiotic exposure. By identifying critical factors that determine bacterial fitness and adaptability, our research lays the foundation for developing new therapeutic strategies against bacterial infections.
Additional Links: PMID-40166241
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@article {pmid40166241,
year = {2025},
author = {Lormand, JD and Savelle, CH and Teschler, JK and López, E and Little, RH and Malone, JG and Yildiz, FH and García-García, MJ and Sondermann, H},
title = {A class of secreted retropepsin-like enzymes is required for osmotic stress tolerance, antibiotic resistance and biofilm formation in Pseudomonas aeruginosa.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2025.03.18.643919},
pmid = {40166241},
issn = {2692-8205},
abstract = {UNLABELLED: Proteases regulate important biological functions. Here we present the structural and functional characterization of three previously uncharacterized aspartic proteases in Pseudomonas aeruginosa . We show that these proteases have structural hallmarks of retropepsin peptidases and play redundant roles for cell survival under hypoosmotic stress conditions. Consequently, we named them retropepsin-like osmotic stress tolerance peptidases (Rlo). Our research shows that while Rlo proteases are homologous to RimB, an aspartic peptidase involved in rhizosphere colonization and plant infection, they contain N-terminal signal peptides and perform distinct biological functions. Mutants lacking all three secreted Rlo peptidases show defects in antibiotic resistance, biofilm formation, and cell morphology. These defects are rescued by mutations in the inactive transglutaminase transmembrane protein RloB and the cytoplasmic ATP-grasp protein RloC, two previously uncharacterized genes in the same operon as one of the Rlo proteases. These studies identify Rlo proteases and rlo operon products as critical factors in clinically relevant processes, making them appealing targets for therapeutic strategies against Pseudomonas infections.
IMPORTANCE: Bacterial infections have become harder to treat due to the ability of pathogens to adapt to different environments and the rise of antimicrobial resistance. This has led to longer illnesses, increased medical costs, and higher mortality rates. The opportunistic pathogen Pseudomonas aeruginosa is particularly problematic because of its inherent resistance to many antibiotics and its capacity to form biofilms, structures that allow bacteria to withstand hostile conditions. Our study uncovers a new class of retropepsin-like proteases in P. aeruginosa that are required for biofilm formation and bacterial survival upon stress conditions, including antibiotic exposure. By identifying critical factors that determine bacterial fitness and adaptability, our research lays the foundation for developing new therapeutic strategies against bacterial infections.},
}
RevDate: 2025-04-02
Effect of gaseous ozone treatment on cells and biofilm of dairy Bacillus spp. isolates.
Frontiers in microbiology, 16:1538456.
Bacillus spp. can produce biofilms and cause recurrent contamination in the food industry. The common clean-in-place (CIP) method is usually employed in sanitizing processing equipment. However, CIP is not always effective in removing biofilms. Ozone represents a promising "green" alternative to control biofilms. In this study, the effect of gaseous ozone (50 ppm) was evaluated in vitro against planktonic and sessile B. cereus and B. subtilis isolates collected from the dairy sector. Planktonic cells were enumerated by plate counts after 10 min, 1 h, and 6 h of ozone treatment. After a short-term (10 min) exposure, a slight reduction in microbial loads (0.66-2.27 ± 0.15 Log10 CFU/mL) was observed for B. cereus strains, whereas a more pronounced reduction (2.90-3.81 ± 0.12 Log10 CFU/mL) was noted in B. subtilis isolates. The microbial load further decreased after 1 h-treatments, around 1.5-3.46 ± 0.11 Log10 CFU/mL for B. cereus strains, and 4.0-5.6 ± 0.11 Log10 CFU/mL for B. subtilis isolates, until complete inactivation of bacterial cells after 6 h of exposure. Moreover, the effect of gaseous ozone treatment (50 ppm, 6 h) was evaluated for its ability to inhibit and eradicate biofilms formed on two common food-contact materials (polystyrene and stainless steel). Sessile B. subtilis cells were the more sensitive to the action of ozone, while a weak effect was highlighted on B. cereus isolates on both surface types. These results were further confirmed by scanning microscopy analysis. The number of cells in the biofilm state was also assessed, showing a not-complete correlation with a decrease in Biofilm Production Indices (BPIs). These findings highlighted the effectiveness of the sanitizing protocol using gaseous ozone in contrasting Bacillus free-living cells, but a not completely counteraction in biofilm formation (inhibition) or eradication of pre-formed biofilm. Thus, the application of ozone could be thought of not alone, but in combination with common sanitization practices to improve their effectiveness.
Additional Links: PMID-40165788
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@article {pmid40165788,
year = {2025},
author = {Catania, AM and Dalmasso, A and Morra, P and Costa, E and Bottero, MT and Di Ciccio, PA},
title = {Effect of gaseous ozone treatment on cells and biofilm of dairy Bacillus spp. isolates.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1538456},
pmid = {40165788},
issn = {1664-302X},
abstract = {Bacillus spp. can produce biofilms and cause recurrent contamination in the food industry. The common clean-in-place (CIP) method is usually employed in sanitizing processing equipment. However, CIP is not always effective in removing biofilms. Ozone represents a promising "green" alternative to control biofilms. In this study, the effect of gaseous ozone (50 ppm) was evaluated in vitro against planktonic and sessile B. cereus and B. subtilis isolates collected from the dairy sector. Planktonic cells were enumerated by plate counts after 10 min, 1 h, and 6 h of ozone treatment. After a short-term (10 min) exposure, a slight reduction in microbial loads (0.66-2.27 ± 0.15 Log10 CFU/mL) was observed for B. cereus strains, whereas a more pronounced reduction (2.90-3.81 ± 0.12 Log10 CFU/mL) was noted in B. subtilis isolates. The microbial load further decreased after 1 h-treatments, around 1.5-3.46 ± 0.11 Log10 CFU/mL for B. cereus strains, and 4.0-5.6 ± 0.11 Log10 CFU/mL for B. subtilis isolates, until complete inactivation of bacterial cells after 6 h of exposure. Moreover, the effect of gaseous ozone treatment (50 ppm, 6 h) was evaluated for its ability to inhibit and eradicate biofilms formed on two common food-contact materials (polystyrene and stainless steel). Sessile B. subtilis cells were the more sensitive to the action of ozone, while a weak effect was highlighted on B. cereus isolates on both surface types. These results were further confirmed by scanning microscopy analysis. The number of cells in the biofilm state was also assessed, showing a not-complete correlation with a decrease in Biofilm Production Indices (BPIs). These findings highlighted the effectiveness of the sanitizing protocol using gaseous ozone in contrasting Bacillus free-living cells, but a not completely counteraction in biofilm formation (inhibition) or eradication of pre-formed biofilm. Thus, the application of ozone could be thought of not alone, but in combination with common sanitization practices to improve their effectiveness.},
}
RevDate: 2025-04-02
CmpDate: 2025-04-01
tesG expression as a potential clinical biomarker for chronic Pseudomonas aeruginosa pulmonary biofilm infections.
BMC medicine, 23(1):191.
BACKGROUND: Pseudomonas aeruginosa infections in the lungs affect millions of children and adults worldwide. To our knowledge, no clinically validated prognostic biomarkers for chronic pulmonary P. aeruginosa infections exist. Therefore, this study aims to identify potential prognostic markers for chronic P. aeruginosa biofilm lung infections.
METHODS: Here, we screened the expression of 11 P. aeruginosa regulatory genes (tesG, algD, lasR, lasA, lasB, pelB, phzF, rhlA, rsmY, rsmZ, and sagS) to identify associations between clinical status and chronic biofilm infection.
RESULTS: RNA was extracted from 210 sputum samples from patients (n = 70) with chronic P. aeruginosa lung infections (mean age; 29.3-56.2 years; 33 female). Strong biofilm formation was correlated with prolonged hospital stays (212.2 days vs. 44.4 days) and increased mortality (46.2% (18)). Strong biofilm formation is associated with increased tesG expression (P = 0.001), influencing extended intensive care unit (P = 0.002) or hospitalisation stays (P = 0.001), pneumonia risk (P = 0.006), and mortality (P = 0.001). Notably, tesG expression is linked to the modulation of systemic and sputum inflammatory responses and predicts biofilm biomass.
CONCLUSIONS: This study provides the first clinical dataset of tesG expression levels as a predictive biomarker for chronic P. aeruginosa pulmonary infections.
Additional Links: PMID-40165235
PubMed:
Citation:
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@article {pmid40165235,
year = {2025},
author = {Wannigama, DL and Hurst, C and Monk, PN and Hartel, G and Ditcham, WGF and Hongsing, P and Phattharapornjaroen, P and Ounjai, P and Torvorapanit, P and Jutivorakool, K and Luk-In, S and Nilgate, S and Rirerm, U and Tanasatitchai, C and Miyanaga, K and Cui, L and Ragupathi, NKD and Rad, SMAH and Khatib, A and Storer, RJ and Ishikawa, H and Amarasiri, M and Charuluxananan, S and Leelahavanichkul, A and Kanjanabuch, T and Higgins, PG and Davies, JC and Stick, SM and Kicic, A and Chatsuwan, T and Shibuya, K and Abe, S},
title = {tesG expression as a potential clinical biomarker for chronic Pseudomonas aeruginosa pulmonary biofilm infections.},
journal = {BMC medicine},
volume = {23},
number = {1},
pages = {191},
pmid = {40165235},
issn = {1741-7015},
mesh = {Humans ; *Biofilms/growth & development ; *Pseudomonas aeruginosa/genetics ; Female ; Male ; *Pseudomonas Infections/microbiology ; Middle Aged ; Adult ; *Biomarkers ; *Sputum/microbiology ; Bacterial Proteins/genetics ; Chronic Disease ; },
abstract = {BACKGROUND: Pseudomonas aeruginosa infections in the lungs affect millions of children and adults worldwide. To our knowledge, no clinically validated prognostic biomarkers for chronic pulmonary P. aeruginosa infections exist. Therefore, this study aims to identify potential prognostic markers for chronic P. aeruginosa biofilm lung infections.
METHODS: Here, we screened the expression of 11 P. aeruginosa regulatory genes (tesG, algD, lasR, lasA, lasB, pelB, phzF, rhlA, rsmY, rsmZ, and sagS) to identify associations between clinical status and chronic biofilm infection.
RESULTS: RNA was extracted from 210 sputum samples from patients (n = 70) with chronic P. aeruginosa lung infections (mean age; 29.3-56.2 years; 33 female). Strong biofilm formation was correlated with prolonged hospital stays (212.2 days vs. 44.4 days) and increased mortality (46.2% (18)). Strong biofilm formation is associated with increased tesG expression (P = 0.001), influencing extended intensive care unit (P = 0.002) or hospitalisation stays (P = 0.001), pneumonia risk (P = 0.006), and mortality (P = 0.001). Notably, tesG expression is linked to the modulation of systemic and sputum inflammatory responses and predicts biofilm biomass.
CONCLUSIONS: This study provides the first clinical dataset of tesG expression levels as a predictive biomarker for chronic P. aeruginosa pulmonary infections.},
}
MeSH Terms:
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Humans
*Biofilms/growth & development
*Pseudomonas aeruginosa/genetics
Female
Male
*Pseudomonas Infections/microbiology
Middle Aged
Adult
*Biomarkers
*Sputum/microbiology
Bacterial Proteins/genetics
Chronic Disease
RevDate: 2025-03-31
Construction of an efficient enzyme-cell@material biocatalyst through the biofilm immobilization of Komagataella phaffii for continuous biocatalysis.
Bioresource technology pii:S0960-8524(25)00426-2 [Epub ahead of print].
The ever-growing demand for cost-effective and green biocatalytic transformations has prompted the rational design and development of robust biocatalytic tools. However, transformations are hindered by limited continuous process and enzymatic instability. Here, 10 Flo family related genes in Komagataella phaffii were systematically evaluated to assess their adhesive properties. For the first time, we identified the KpFlo11C domain of BSC1p as facilitating cell aggregation on carriers, thereby enhancing the biofilm immobilization process. Furthermore, an engineered K. phaffii strain, fixing β-galactosidase on the cell surface, was constructed by optimizing the signal peptide and gene dosage, for enhancing the efficiency of enzyme targeting and anchoring, as well as the proportion of cells displaying the enzyme. Finally, the KpFlo11C domain was overexpressed in this K. phaffii cell display system to construct the enzyme-cell@material biocatalyst, which exhibited robust continuous production of galacto-oligosaccharides (GOS) at a rate of 8.16 g/L/h in a 6-L fermenter. The development of this enzyme-cell@material biocatalyst, which offers a highly efficient, stable, low-cost, and simplified biocatalytic process, provides a direction for the application of other yeasts in large-scale industrial continuous production.
Additional Links: PMID-40164359
Publisher:
PubMed:
Citation:
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@article {pmid40164359,
year = {2025},
author = {Zhou, C and Zhu, Y and Ren, P and Leng, J and Xia, X and Chen, T and Sun, W and Yang, P and Niu, H and Chen, Y and Ying, H},
title = {Construction of an efficient enzyme-cell@material biocatalyst through the biofilm immobilization of Komagataella phaffii for continuous biocatalysis.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {132460},
doi = {10.1016/j.biortech.2025.132460},
pmid = {40164359},
issn = {1873-2976},
abstract = {The ever-growing demand for cost-effective and green biocatalytic transformations has prompted the rational design and development of robust biocatalytic tools. However, transformations are hindered by limited continuous process and enzymatic instability. Here, 10 Flo family related genes in Komagataella phaffii were systematically evaluated to assess their adhesive properties. For the first time, we identified the KpFlo11C domain of BSC1p as facilitating cell aggregation on carriers, thereby enhancing the biofilm immobilization process. Furthermore, an engineered K. phaffii strain, fixing β-galactosidase on the cell surface, was constructed by optimizing the signal peptide and gene dosage, for enhancing the efficiency of enzyme targeting and anchoring, as well as the proportion of cells displaying the enzyme. Finally, the KpFlo11C domain was overexpressed in this K. phaffii cell display system to construct the enzyme-cell@material biocatalyst, which exhibited robust continuous production of galacto-oligosaccharides (GOS) at a rate of 8.16 g/L/h in a 6-L fermenter. The development of this enzyme-cell@material biocatalyst, which offers a highly efficient, stable, low-cost, and simplified biocatalytic process, provides a direction for the application of other yeasts in large-scale industrial continuous production.},
}
RevDate: 2025-03-31
Comparative evaluation of biologically and chemically synthesized zinc oxide nanoparticles for preventing Candida auris biofilm.
Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine [Epub ahead of print].
Candidozyma auris (formerly Candida auris) is a multidrug-resistant yeast that poses a significant global health threat due to its ability to form biofilms and resist various antifungal treatments. This study evaluates and compares the antifungal efficacy of biologically synthesized zinc oxide nanoparticles (ZnO-NP-B) and chemically synthesized ZnO nanoparticles (ZnO-NP-C1 and ZnO-NP-C2), developed using the dry-wet chemical method and sol-gel method, respectively. ZnO-NP-B was synthesized using Lactobacillus gasseri. The nanoparticles were characterized for size, charge, and morphology using Particle Size Analyzer, photon correlation spectroscopy with a 90 Plus Zetasizer, and scanning electron microscopy (SEM), respectively. The antifungal activity was assessed through minimum inhibitory concentration (MIC50) determination, biofilm inhibition assays by XTT assay, and gene expression analysis. ZnO-NP-C1 exhibited the highest antifungal activity against C. auris planktonic cells, with a MIC50 value of 61.9 ± 3.3 µg/ml, followed by ZnO-NP-C2 (151 ± 7.83 µg/ml), whereas ZnO-NP-B showed limited efficacy (MIC50 = 1 mg/ml). Chemically synthesized ZnO-NPs, particularly ZnO-NP-C2, did not induce overexpression of resistance genes (CDR1, MDR1, ERG2, ERG11, FKS1, CHS1), whereas ZnO-NP-B triggered their upregulation, potentially promoting resistance. ZnO-NP-C1 was the most effective in preventing biofilm formation, reducing C. auris adhesion by 67.9 ± 2.35% at 150 µg/ml, while ZnO-NP-B exhibited negligible inhibition. Gene expression analysis further confirmed that ZnO-NP-C1 significantly downregulated adhesive genes (ALS5, IFF4, CSA1) by up to 0.37 ± 0.006, 0.043 ± 0.002, and 0.06 ± 0.0004, respectively. These findings highlight the potential of ZnO-NP-C1 as a promising antifungal agent for preventing C. auris biofilms, emphasizing the critical role of synthesis methods in optimizing nanoparticle properties for antifungal applications.
Additional Links: PMID-40163280
PubMed:
Citation:
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@article {pmid40163280,
year = {2025},
author = {Fayed, B and El-Sayed, HS and Luo, S and Reda, AE},
title = {Comparative evaluation of biologically and chemically synthesized zinc oxide nanoparticles for preventing Candida auris biofilm.},
journal = {Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine},
volume = {},
number = {},
pages = {},
pmid = {40163280},
issn = {1572-8773},
abstract = {Candidozyma auris (formerly Candida auris) is a multidrug-resistant yeast that poses a significant global health threat due to its ability to form biofilms and resist various antifungal treatments. This study evaluates and compares the antifungal efficacy of biologically synthesized zinc oxide nanoparticles (ZnO-NP-B) and chemically synthesized ZnO nanoparticles (ZnO-NP-C1 and ZnO-NP-C2), developed using the dry-wet chemical method and sol-gel method, respectively. ZnO-NP-B was synthesized using Lactobacillus gasseri. The nanoparticles were characterized for size, charge, and morphology using Particle Size Analyzer, photon correlation spectroscopy with a 90 Plus Zetasizer, and scanning electron microscopy (SEM), respectively. The antifungal activity was assessed through minimum inhibitory concentration (MIC50) determination, biofilm inhibition assays by XTT assay, and gene expression analysis. ZnO-NP-C1 exhibited the highest antifungal activity against C. auris planktonic cells, with a MIC50 value of 61.9 ± 3.3 µg/ml, followed by ZnO-NP-C2 (151 ± 7.83 µg/ml), whereas ZnO-NP-B showed limited efficacy (MIC50 = 1 mg/ml). Chemically synthesized ZnO-NPs, particularly ZnO-NP-C2, did not induce overexpression of resistance genes (CDR1, MDR1, ERG2, ERG11, FKS1, CHS1), whereas ZnO-NP-B triggered their upregulation, potentially promoting resistance. ZnO-NP-C1 was the most effective in preventing biofilm formation, reducing C. auris adhesion by 67.9 ± 2.35% at 150 µg/ml, while ZnO-NP-B exhibited negligible inhibition. Gene expression analysis further confirmed that ZnO-NP-C1 significantly downregulated adhesive genes (ALS5, IFF4, CSA1) by up to 0.37 ± 0.006, 0.043 ± 0.002, and 0.06 ± 0.0004, respectively. These findings highlight the potential of ZnO-NP-C1 as a promising antifungal agent for preventing C. auris biofilms, emphasizing the critical role of synthesis methods in optimizing nanoparticle properties for antifungal applications.},
}
RevDate: 2025-03-31
Transcriptional signatures associated with the survival of Escherichia coli biofilm during treatment with plasma-activated water.
Biofilm, 9:100266.
Biofilm formation on surfaces, tools and equipment can damage their quality and lead to high repair or replacement costs. Plasma-activated water (PAW), a new technology, has shown promise in killing biofilm and non-biofilm bacteria due to reactive oxygen and nitrogen species (RONS), particularly superoxide. However, the exact genetic mechanisms behind PAW's effectiveness against biofilms remain unclear. Here, we examined the stress responses of Escherichia coli biofilms exposed to sub-lethal PAW treatment using bulk RNA sequencing and transcriptomics. We compared gene expression in PAW-treated E. coli biofilms with and without superoxide removal, achieved by adding the scavenger Tiron. Biofilms treated with PAW exhibited a 40 % variation in gene expression compared to those treated with PAW-Tiron and controls. Specifically, PAW treatment resulted in 478 upregulated genes (>1.5 log2FC) and 186 downregulated genes (<-1.5 log2FC) compared to the control. Pathway and biological process enrichment analysis revealed significant upregulation of genes involved in sulfur metabolism, ATP-binding transporter, amino acid metabolism, hypochlorite response systems and oxidative phosphorylation in PAW-treated biofilms compared to control. Biofilm viability and intracellular RONS accumulation were tested for E. coli mutants lacking key genes from these pathways. Knockout mutants of thioredoxin (trxC), thiosulfate-binding proteins (cysP), and NADH dehydrogenase subunit (nuoM) showed significantly reduced biofilm viability after PAW treatment. Notably, ΔtrxC biofilms had the highest intracellular ROS accumulation, as revealed by 2',7'-dichlorofluorescin diacetate staining after PAW treatment. This confirms the importance of these genes in managing oxidative stress caused by PAW and highlights the significance of superoxide in PAW's bactericidal effects. Overall, our findings shed light on the specific genes and pathways that help E. coli biofilms survive and respond to PAW treatment, offering a new understanding of plasma technology and its anti-biofilm mechanisms.
Additional Links: PMID-40161322
PubMed:
Citation:
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@article {pmid40161322,
year = {2025},
author = {Vyas, HKN and Hoque, MM and Xia, B and Alam, D and Cullen, PJ and Rice, SA and Mai-Prochnow, A},
title = {Transcriptional signatures associated with the survival of Escherichia coli biofilm during treatment with plasma-activated water.},
journal = {Biofilm},
volume = {9},
number = {},
pages = {100266},
pmid = {40161322},
issn = {2590-2075},
abstract = {Biofilm formation on surfaces, tools and equipment can damage their quality and lead to high repair or replacement costs. Plasma-activated water (PAW), a new technology, has shown promise in killing biofilm and non-biofilm bacteria due to reactive oxygen and nitrogen species (RONS), particularly superoxide. However, the exact genetic mechanisms behind PAW's effectiveness against biofilms remain unclear. Here, we examined the stress responses of Escherichia coli biofilms exposed to sub-lethal PAW treatment using bulk RNA sequencing and transcriptomics. We compared gene expression in PAW-treated E. coli biofilms with and without superoxide removal, achieved by adding the scavenger Tiron. Biofilms treated with PAW exhibited a 40 % variation in gene expression compared to those treated with PAW-Tiron and controls. Specifically, PAW treatment resulted in 478 upregulated genes (>1.5 log2FC) and 186 downregulated genes (<-1.5 log2FC) compared to the control. Pathway and biological process enrichment analysis revealed significant upregulation of genes involved in sulfur metabolism, ATP-binding transporter, amino acid metabolism, hypochlorite response systems and oxidative phosphorylation in PAW-treated biofilms compared to control. Biofilm viability and intracellular RONS accumulation were tested for E. coli mutants lacking key genes from these pathways. Knockout mutants of thioredoxin (trxC), thiosulfate-binding proteins (cysP), and NADH dehydrogenase subunit (nuoM) showed significantly reduced biofilm viability after PAW treatment. Notably, ΔtrxC biofilms had the highest intracellular ROS accumulation, as revealed by 2',7'-dichlorofluorescin diacetate staining after PAW treatment. This confirms the importance of these genes in managing oxidative stress caused by PAW and highlights the significance of superoxide in PAW's bactericidal effects. Overall, our findings shed light on the specific genes and pathways that help E. coli biofilms survive and respond to PAW treatment, offering a new understanding of plasma technology and its anti-biofilm mechanisms.},
}
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RJR Experience and Expertise
Researcher
Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.
Educator
Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.
Administrator
Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.
Technologist
Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.
Publisher
While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.
Speaker
Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.
Facilitator
Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.
Designer
Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.
RJR Picks from Around the Web (updated 11 MAY 2018 )
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Fossils of miniature humans (hobbits) discovered in Indonesia
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Dinosaur tail, complete with feathers, found preserved in amber.
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Mysterious fast radio burst (FRB) detected in the distant universe.
Big Data & Informatics
Big Data: Buzzword or Big Deal?
Hacking the genome: Identifying anonymized human subjects using publicly available data.