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RJR: Recommended Bibliography 19 Oct 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: 2025-10-18
A bacteriophage with dual host specificity for canine and porcine Bordetella bronchiseptica: Characterization and biofilm disruption potential.
Virology, 613:110714 pii:S0042-6822(25)00328-9 [Epub ahead of print].
Bordetella bronchiseptica is a pathogen responsible for canine infectious tracheobronchitis (kennel cough) and porcine atrophic rhinitis, and it can cause respiratory infections in a variety of mammalian hosts. In recent years, the extensive use of antibiotics has resulted in increasingly severe antibiotic resistance, consequently driving significant interest in bacteriophages as a potential alternative to antibiotics. In this study, bacteriophage PBb001 isolated from swine farm wastewater in Yantai, Shandong, exhibited lytic activity against Bordetella bronchiseptica, including strains derived from canine and swine hosts. Bacteriophage PBb001 exhibited a latent period of 30 min and a burst size of approximately 323 plaque-forming units (PFU) per cell. The phage exhibited robust stability across a temperature range of 4-60 °C and pH conditions of 3-11, with an optimal multiplicity of infection (MOI) of 0.1. Genomic analysis revealed that PBb001 possesses a linear double-stranded DNA genome of 44,808 bp, with no lysogeny genes, virulence factors, or antibiotic resistance genes detected. In vitro antibacterial assays showed that PBb001 significantly reduced optical density (OD600, reflecting bacterial growth inhibition) and viable bacterial counts in planktonic cultures. Additionally, PBb001 effectively suppressed biofilm formation and disrupted pre-existing biofilms, as evidenced by reduced OD595 values and decreased viable bacterial counts in biofilm-associated assays. These results collectively suggest that PBb001 holds significant potential for controlling B. bronchiseptica infections and represents a potential candidate for further development as an antibiotic alternative.
Additional Links: PMID-41108833
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PubMed:
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@article {pmid41108833,
year = {2025},
author = {Li, C and Tan, L and Ma, Y and Li, Z and Xu, S and Zheng, X and Fang, H and Hong, J and Zhu, Q and Huo, X and Guo, H and Zhang, W},
title = {A bacteriophage with dual host specificity for canine and porcine Bordetella bronchiseptica: Characterization and biofilm disruption potential.},
journal = {Virology},
volume = {613},
number = {},
pages = {110714},
doi = {10.1016/j.virol.2025.110714},
pmid = {41108833},
issn = {1096-0341},
abstract = {Bordetella bronchiseptica is a pathogen responsible for canine infectious tracheobronchitis (kennel cough) and porcine atrophic rhinitis, and it can cause respiratory infections in a variety of mammalian hosts. In recent years, the extensive use of antibiotics has resulted in increasingly severe antibiotic resistance, consequently driving significant interest in bacteriophages as a potential alternative to antibiotics. In this study, bacteriophage PBb001 isolated from swine farm wastewater in Yantai, Shandong, exhibited lytic activity against Bordetella bronchiseptica, including strains derived from canine and swine hosts. Bacteriophage PBb001 exhibited a latent period of 30 min and a burst size of approximately 323 plaque-forming units (PFU) per cell. The phage exhibited robust stability across a temperature range of 4-60 °C and pH conditions of 3-11, with an optimal multiplicity of infection (MOI) of 0.1. Genomic analysis revealed that PBb001 possesses a linear double-stranded DNA genome of 44,808 bp, with no lysogeny genes, virulence factors, or antibiotic resistance genes detected. In vitro antibacterial assays showed that PBb001 significantly reduced optical density (OD600, reflecting bacterial growth inhibition) and viable bacterial counts in planktonic cultures. Additionally, PBb001 effectively suppressed biofilm formation and disrupted pre-existing biofilms, as evidenced by reduced OD595 values and decreased viable bacterial counts in biofilm-associated assays. These results collectively suggest that PBb001 holds significant potential for controlling B. bronchiseptica infections and represents a potential candidate for further development as an antibiotic alternative.},
}
RevDate: 2025-10-18
Characterization of a Regulatory Network Promoting Cell Fate Segregation in the Myxococcus xanthus Biofilm.
Molecular microbiology [Epub ahead of print].
Most bacterial populations exhibit phenotypic heterogeneity to increase fitness in rapidly changing environmental conditions. Myxococcus xanthus is an environmental bacterium that displays pronounced phenotypic heterogeneity in its complex lifecycle. Under nutrient limitation, M. xanthus produces a specialized biofilm in which cells segregate into two spatially distinct fates: fruiting bodies filled with spores and a persister-like peripheral rod population. Little is known about the regulatory mechanisms controlling peripheral rods. To begin to investigate this cell fate segregation mechanism, we focused on the EspAC signaling system, which controls the accumulation of MrpC, a central transcription factor necessary to induce fruiting body formation. Single-cell reporters and in situ confocal microscopy demonstrated that expression of the esp genes is enriched in the peripheral rods. We identified three transcription factors necessary for espAC transcriptional control: MrpC, FruA, a transcription factor that coordinates sporulation within fruiting bodies, and the xenobiotic response element, Xre0228. We demonstrate that MrpC directly activates espA and espC; FruA represses espC but not espA; and Xre0228 activates espA but represses espC. These genetic interactions fit common network motifs that promote or stabilize phenotypic heterogeneity. We propose a model by which cell fate segregation is directed, stabilized, and tuned to environmental conditions.
Additional Links: PMID-41108538
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@article {pmid41108538,
year = {2025},
author = {Kasto, S and Higgs, PI},
title = {Characterization of a Regulatory Network Promoting Cell Fate Segregation in the Myxococcus xanthus Biofilm.},
journal = {Molecular microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/mmi.70028},
pmid = {41108538},
issn = {1365-2958},
support = {IOS-1651921//National Science Foundation/ ; //Michigan State University/ ; //Wayne State University/ ; },
abstract = {Most bacterial populations exhibit phenotypic heterogeneity to increase fitness in rapidly changing environmental conditions. Myxococcus xanthus is an environmental bacterium that displays pronounced phenotypic heterogeneity in its complex lifecycle. Under nutrient limitation, M. xanthus produces a specialized biofilm in which cells segregate into two spatially distinct fates: fruiting bodies filled with spores and a persister-like peripheral rod population. Little is known about the regulatory mechanisms controlling peripheral rods. To begin to investigate this cell fate segregation mechanism, we focused on the EspAC signaling system, which controls the accumulation of MrpC, a central transcription factor necessary to induce fruiting body formation. Single-cell reporters and in situ confocal microscopy demonstrated that expression of the esp genes is enriched in the peripheral rods. We identified three transcription factors necessary for espAC transcriptional control: MrpC, FruA, a transcription factor that coordinates sporulation within fruiting bodies, and the xenobiotic response element, Xre0228. We demonstrate that MrpC directly activates espA and espC; FruA represses espC but not espA; and Xre0228 activates espA but represses espC. These genetic interactions fit common network motifs that promote or stabilize phenotypic heterogeneity. We propose a model by which cell fate segregation is directed, stabilized, and tuned to environmental conditions.},
}
RevDate: 2025-10-18
Development of a biofilm reactor using nano Fe3O4-modified biochar and red mud: Enhanced synergistic removal of nitrate, cadmium, and acetaminophen.
Environmental research, 287:123142 pii:S0013-9351(25)02395-3 [Epub ahead of print].
Insufficient C/N ratio and a wide range of pollutants tend to limit the treatment of secondary effluents from wastewater treatment plants (WWTPs). In this study, a biofilm reactor was established to achieve nitrate (NO3[-]) removal in WWTPs, based on ferrous-driven denitrification. The bioreactor was composed of nano-Fe3O4 modified biochar and red mud (nano-Fe3O4@BC-RM) with the introduction of Zoogloea sp. ZP7. NO3[-] removal efficiency (NRE) achieved 97.04 % when HRT = 6 h, C/N = 1.5, pH = 7, and still maintained more than 80 % in the presence of cadmium (Cd[2+]) and acetaminophen (ACT). Moreover, the removal of Cd[2+] and ACT was mainly through adsorption by the extracellular polymeric substances (EPS) and bio-iron precipitation. The large enrichment of microorganisms with denitrification and iron cycling functions in the biological community maintained the stable operation of the bioreactor. This study provides a valuable experience for the treatment of low C/N ratio wastewater and an innovative solution to solid waste.
Additional Links: PMID-41106660
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PubMed:
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@article {pmid41106660,
year = {2025},
author = {Li, T and Li, X and Su, J and Liu, S and Bai, Y and Li, X},
title = {Development of a biofilm reactor using nano Fe3O4-modified biochar and red mud: Enhanced synergistic removal of nitrate, cadmium, and acetaminophen.},
journal = {Environmental research},
volume = {287},
number = {},
pages = {123142},
doi = {10.1016/j.envres.2025.123142},
pmid = {41106660},
issn = {1096-0953},
abstract = {Insufficient C/N ratio and a wide range of pollutants tend to limit the treatment of secondary effluents from wastewater treatment plants (WWTPs). In this study, a biofilm reactor was established to achieve nitrate (NO3[-]) removal in WWTPs, based on ferrous-driven denitrification. The bioreactor was composed of nano-Fe3O4 modified biochar and red mud (nano-Fe3O4@BC-RM) with the introduction of Zoogloea sp. ZP7. NO3[-] removal efficiency (NRE) achieved 97.04 % when HRT = 6 h, C/N = 1.5, pH = 7, and still maintained more than 80 % in the presence of cadmium (Cd[2+]) and acetaminophen (ACT). Moreover, the removal of Cd[2+] and ACT was mainly through adsorption by the extracellular polymeric substances (EPS) and bio-iron precipitation. The large enrichment of microorganisms with denitrification and iron cycling functions in the biological community maintained the stable operation of the bioreactor. This study provides a valuable experience for the treatment of low C/N ratio wastewater and an innovative solution to solid waste.},
}
RevDate: 2025-10-17
Coupled syngas fermentation to multiple oxidized contaminants reduction in a membrane biofilm reactor.
Water research, 288(Pt B):124749 pii:S0043-1354(25)01652-5 [Epub ahead of print].
Multiple oxidized contaminants (MOC) frequently coexist in water sources, posing significant human health risks. Major challenges in the biological reduction of MOC include the lack of effective carbon sources and competition for a sole electron donor. This study demonstrates the feasibility of using syngas fermentation in a lab-scale membrane biofilm reactor (MBfR) to provide dual electron donors, volatile fatty acids (VFAs) and H2, to support simultaneous removal of nitrate, selenate, bromate, and perchlorate. MBfR was employed for efficient gas delivery, achieving complete MOC removal with non-toxic end products (N2, Se[0], Br[-], and Cl[-]) generated over 200 days of operation. In situ batch tests revealed that MOC reduction was synergistically driven by H2 and VFAs generated via gas fermentation. H2 primarily facilitated bromate reduction, VFAs enhanced perchlorate reduction, while nitrate and selenate were reduced by both electron donors. Maximal removal rates reached 108.1 mg N/L/d, 6.9 mg Br/L/d, 5.5 mg Cl/L/d, and 5.4 mg Se/L/d when both H2 and VFAs were utilized. High-throughput 16S rRNA gene amplicon sequencing suggested gas fermenters (Acetobacterium and Clostridium), autotrophic MOC-reducing taxa (e.g., Shewanella), and heterotrophic MOC-reducing taxa (e.g., Clostridium, Desulfovibrio) as the dominant community members, underscoring their roles in syngas conversion and contaminant reduction. These findings highlight the potential of integrating syngas fermentation in MBfRs as an efficient strategy for simultaneous MOC removal, providing a promising approach for water remediation.
Additional Links: PMID-41106019
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PubMed:
Citation:
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@article {pmid41106019,
year = {2025},
author = {Zhang, Y and Zhou, L and Wu, M and Liu, T and Niu, C and Hu, Y and Ma, Y and Lu, Y and Zhang, W and Guo, J},
title = {Coupled syngas fermentation to multiple oxidized contaminants reduction in a membrane biofilm reactor.},
journal = {Water research},
volume = {288},
number = {Pt B},
pages = {124749},
doi = {10.1016/j.watres.2025.124749},
pmid = {41106019},
issn = {1879-2448},
abstract = {Multiple oxidized contaminants (MOC) frequently coexist in water sources, posing significant human health risks. Major challenges in the biological reduction of MOC include the lack of effective carbon sources and competition for a sole electron donor. This study demonstrates the feasibility of using syngas fermentation in a lab-scale membrane biofilm reactor (MBfR) to provide dual electron donors, volatile fatty acids (VFAs) and H2, to support simultaneous removal of nitrate, selenate, bromate, and perchlorate. MBfR was employed for efficient gas delivery, achieving complete MOC removal with non-toxic end products (N2, Se[0], Br[-], and Cl[-]) generated over 200 days of operation. In situ batch tests revealed that MOC reduction was synergistically driven by H2 and VFAs generated via gas fermentation. H2 primarily facilitated bromate reduction, VFAs enhanced perchlorate reduction, while nitrate and selenate were reduced by both electron donors. Maximal removal rates reached 108.1 mg N/L/d, 6.9 mg Br/L/d, 5.5 mg Cl/L/d, and 5.4 mg Se/L/d when both H2 and VFAs were utilized. High-throughput 16S rRNA gene amplicon sequencing suggested gas fermenters (Acetobacterium and Clostridium), autotrophic MOC-reducing taxa (e.g., Shewanella), and heterotrophic MOC-reducing taxa (e.g., Clostridium, Desulfovibrio) as the dominant community members, underscoring their roles in syngas conversion and contaminant reduction. These findings highlight the potential of integrating syngas fermentation in MBfRs as an efficient strategy for simultaneous MOC removal, providing a promising approach for water remediation.},
}
RevDate: 2025-10-17
CmpDate: 2025-10-17
Carbonizing technology enables Sanguisorbae Radix to inhibit yeast-to-hypha differentiation and biofilm formation in Candida albicans.
PloS one, 20(10):e0334659 pii:PONE-D-25-10562.
Sanguisorbae Radix (SR) has been employed as an herbal medicine over centuries. Charred SR (CSR), acquired via carbonization after the charred stir-frying of SR, demonstrates superior antimicrobial activity compared to SR. The aim of the study was to identify how carbonizing technology enhanced the ability of SR to inhibit the transformation from yeast to hypha and biofilm formation in C. albicans. In this paper, a vulvovaginal candidiasis (VVC) mouse model was used to evaluate the therapeutic effects. After CSR treatment, VVC mouse models nearly eliminated hyphal C. albicans adhering to the vaginal mucosa. The inhibitory activities of CSR on C. albicans biofilm formation and hyphal growth were assessed through quantitative biofilm analysis, morphological observations, and gene expression studies in vitro. Since the hyphal form signifies the initiation of biofilm development, this study confirmed CSR's remarkable inhibitory effect on C. albicans biofilm formation and hyphal growth. These effects were significantly weaker with SR. Additionally, the impact of carbonization on the composition of active compounds was analyzed. Carbonization significantly increased the content of ellagic acid (EA) and pyrogallic acid (PYG) by 7.44-fold and 28.09-fold, respectively. Both EA and PYG inhibited C. albicans biofilms and hyphal growth, with EA showing a more pronounced inhibitory effect. Finally, we concluded that carbonization technology enables SR to inhibit the yeast-to-hypha transition and biofilm formation in C. albicans by increase the levels of EA and PYG. EA was identified as the primary bioactive compound responsible for CSR's anti-biofilm effects.
Additional Links: PMID-41105697
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PubMed:
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@article {pmid41105697,
year = {2025},
author = {Cheng, X and Song, J and Hu, Q and Wu, H and Song, B and Ma, R and Gao, J and Wang, Y and Tong, H and Gu, W and Zhao, H},
title = {Carbonizing technology enables Sanguisorbae Radix to inhibit yeast-to-hypha differentiation and biofilm formation in Candida albicans.},
journal = {PloS one},
volume = {20},
number = {10},
pages = {e0334659},
doi = {10.1371/journal.pone.0334659},
pmid = {41105697},
issn = {1932-6203},
mesh = {*Biofilms/drug effects/growth & development ; *Candida albicans/drug effects/physiology/growth & development ; *Hyphae/drug effects/growth & development ; Female ; Animals ; Mice ; *Candidiasis, Vulvovaginal/drug therapy/microbiology ; *Antifungal Agents/pharmacology/chemistry ; *Plant Extracts/pharmacology/chemistry ; Disease Models, Animal ; },
abstract = {Sanguisorbae Radix (SR) has been employed as an herbal medicine over centuries. Charred SR (CSR), acquired via carbonization after the charred stir-frying of SR, demonstrates superior antimicrobial activity compared to SR. The aim of the study was to identify how carbonizing technology enhanced the ability of SR to inhibit the transformation from yeast to hypha and biofilm formation in C. albicans. In this paper, a vulvovaginal candidiasis (VVC) mouse model was used to evaluate the therapeutic effects. After CSR treatment, VVC mouse models nearly eliminated hyphal C. albicans adhering to the vaginal mucosa. The inhibitory activities of CSR on C. albicans biofilm formation and hyphal growth were assessed through quantitative biofilm analysis, morphological observations, and gene expression studies in vitro. Since the hyphal form signifies the initiation of biofilm development, this study confirmed CSR's remarkable inhibitory effect on C. albicans biofilm formation and hyphal growth. These effects were significantly weaker with SR. Additionally, the impact of carbonization on the composition of active compounds was analyzed. Carbonization significantly increased the content of ellagic acid (EA) and pyrogallic acid (PYG) by 7.44-fold and 28.09-fold, respectively. Both EA and PYG inhibited C. albicans biofilms and hyphal growth, with EA showing a more pronounced inhibitory effect. Finally, we concluded that carbonization technology enables SR to inhibit the yeast-to-hypha transition and biofilm formation in C. albicans by increase the levels of EA and PYG. EA was identified as the primary bioactive compound responsible for CSR's anti-biofilm effects.},
}
MeSH Terms:
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*Biofilms/drug effects/growth & development
*Candida albicans/drug effects/physiology/growth & development
*Hyphae/drug effects/growth & development
Female
Animals
Mice
*Candidiasis, Vulvovaginal/drug therapy/microbiology
*Antifungal Agents/pharmacology/chemistry
*Plant Extracts/pharmacology/chemistry
Disease Models, Animal
RevDate: 2025-10-17
Biofilm Formation and Antibiotic Resistance in Uropathogenic Escherichia coli: A Molecular Characterization and Antibiogram Study.
Microbial drug resistance (Larchmont, N.Y.) [Epub ahead of print].
Biofilm formation is a key virulence factor in urinary tract infections, and Escherichia coli (E. coli) serves as a prominent causative agent, more resistant to antimicrobial agents. This study focused on isolation and phenotypic and genotypic characterization of E. coli from urine samples on the basis of their biofilm-forming capacity. In the present study, a total of 804 human urine samples were collected from different clinical facilities of Faisalabad. After phenotypic and genotypic affirmation, biofilm forming potential of uropathogenic E. coli (UPEC) was determined by using microtiter plate assay (MPA) and the Congo red agar method. Antimicrobial susceptibility testing was conducted, and a comparison was executed between biofilm formers and non-formers. Biofilm production by the MPA and Congo red agar methods was 88% and 68%, respectively. UPEC isolates showed maximum resistance to amoxicillin-clavulanate (97%), cefoparazone (93%), cefotaxime (91%), and ampicillin (90%). Significant association between resistance to antibiotic and biofilm formation with p value <0.05 was observed in case of piperacillin-tazobactam, imipenem, meropenem, amikacin, norfloxacin, nitrofurantoin, polymyxin B, and nalidixic acid. Biofilm producer strains were progressed for molecular characterization using polymerase chain reaction for biofilm-forming genes including fimH, csgA, bcsA, agn43, papC, and focG, which showed prevalence of 89% (118/132), 87% (116/132), 86% (114/132), 81% (107/132), 47% (61/132), and 33% (43/132), respectively.
Additional Links: PMID-41103260
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PubMed:
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@article {pmid41103260,
year = {2025},
author = {Saman, and Siddique, AB and Aslam, B and Nawaz, Z},
title = {Biofilm Formation and Antibiotic Resistance in Uropathogenic Escherichia coli: A Molecular Characterization and Antibiogram Study.},
journal = {Microbial drug resistance (Larchmont, N.Y.)},
volume = {},
number = {},
pages = {},
doi = {10.1177/10766294251389587},
pmid = {41103260},
issn = {1931-8448},
abstract = {Biofilm formation is a key virulence factor in urinary tract infections, and Escherichia coli (E. coli) serves as a prominent causative agent, more resistant to antimicrobial agents. This study focused on isolation and phenotypic and genotypic characterization of E. coli from urine samples on the basis of their biofilm-forming capacity. In the present study, a total of 804 human urine samples were collected from different clinical facilities of Faisalabad. After phenotypic and genotypic affirmation, biofilm forming potential of uropathogenic E. coli (UPEC) was determined by using microtiter plate assay (MPA) and the Congo red agar method. Antimicrobial susceptibility testing was conducted, and a comparison was executed between biofilm formers and non-formers. Biofilm production by the MPA and Congo red agar methods was 88% and 68%, respectively. UPEC isolates showed maximum resistance to amoxicillin-clavulanate (97%), cefoparazone (93%), cefotaxime (91%), and ampicillin (90%). Significant association between resistance to antibiotic and biofilm formation with p value <0.05 was observed in case of piperacillin-tazobactam, imipenem, meropenem, amikacin, norfloxacin, nitrofurantoin, polymyxin B, and nalidixic acid. Biofilm producer strains were progressed for molecular characterization using polymerase chain reaction for biofilm-forming genes including fimH, csgA, bcsA, agn43, papC, and focG, which showed prevalence of 89% (118/132), 87% (116/132), 86% (114/132), 81% (107/132), 47% (61/132), and 33% (43/132), respectively.},
}
RevDate: 2025-10-17
Cationic Polymer for Aligner and Oral Biofilm Removal via Osmotic Mechanism.
Journal of dental research [Epub ahead of print].
Dental caries caused by cariogenic biofilms is a significant challenge in modern dentistry, especially with aligner treatments, where biofilms can easily build up during prolonged use and lead to serious risks. Traditional antimicrobial methods focus on bacterial killing and often overlook the vital task of removing the biofilm matrix, allowing the quick reattachment of bacteria. In this study, we introduce an osmotic-driven biofilm removal strategy that harnesses osmotic dynamics to remove entire biofilm structures physically. Internal osmotic pressure is generated by a precisely designed cationic copolymer, triggering controlled detachment of the biofilm matrix. When tested in vitro on Streptococcus mutans biofilms grown on dental aligners and in hard-to-reach interproximal spaces, our method eliminated biofilms more efficiently than traditional cleaning methods. The technique showed concentration-dependent cytotoxicity, highlighting the need for further polymer optimization. Overall, our osmotic-driven biofilm removal strategy significantly advances biofilm control strategies, offering a novel solution for improving oral health and presenting a potential physical removal method for medical settings.
Additional Links: PMID-41103003
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PubMed:
Citation:
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@article {pmid41103003,
year = {2025},
author = {Seo, K and Moon, J and Bhat, R and Mangal, U and Choi, SH and Kwon, JS},
title = {Cationic Polymer for Aligner and Oral Biofilm Removal via Osmotic Mechanism.},
journal = {Journal of dental research},
volume = {},
number = {},
pages = {220345251368263},
doi = {10.1177/00220345251368263},
pmid = {41103003},
issn = {1544-0591},
abstract = {Dental caries caused by cariogenic biofilms is a significant challenge in modern dentistry, especially with aligner treatments, where biofilms can easily build up during prolonged use and lead to serious risks. Traditional antimicrobial methods focus on bacterial killing and often overlook the vital task of removing the biofilm matrix, allowing the quick reattachment of bacteria. In this study, we introduce an osmotic-driven biofilm removal strategy that harnesses osmotic dynamics to remove entire biofilm structures physically. Internal osmotic pressure is generated by a precisely designed cationic copolymer, triggering controlled detachment of the biofilm matrix. When tested in vitro on Streptococcus mutans biofilms grown on dental aligners and in hard-to-reach interproximal spaces, our method eliminated biofilms more efficiently than traditional cleaning methods. The technique showed concentration-dependent cytotoxicity, highlighting the need for further polymer optimization. Overall, our osmotic-driven biofilm removal strategy significantly advances biofilm control strategies, offering a novel solution for improving oral health and presenting a potential physical removal method for medical settings.},
}
RevDate: 2025-10-16
CmpDate: 2025-10-17
Subinhibitory Concentrations of Oxacillin Alter Motility, Biofilm Production, and Transformation Capability of the Oxacillinase-Producing Acinetobacter baumannii.
Current microbiology, 82(12):562.
Subinhibitory concentrations of various antibiotics can exacerbate microbial virulence. Acinetobacter baumannii is often resistant to oxacillin; however, the effect of low oxacillin concentrations on oxacillinase-producing bacteria remains unclear. Herein, oxacillinase producer A. baumannii ATCC-strains 2093 (motile) and 19606 (non-motile) were pre-exposed to sub-bactericidal concentrations (subMBC) of oxacillin (0.25, 0.5, and 1.0 mg/mL) and incubated at 37 °C. Growth kinetics, twitching and swarming-like motility, biofilm formation, exopolysaccharide production, transformation capability, and gene expression were determined. All oxacillin subMBC conditions exerted bacteriostatic effects in both strains. Pre-exposing the motile strain with 0.25 and 0.5 mg/mL of oxacillin for 1 h increased the twitching motility (4.2 ± 0.3 cm; control = 3.5 cm), whereas pre-exposure for 2 h it increased swarming-like motility (2.95 ± 0.15 cm; control = 2.7 cm). This strain also increased the biofilm production by effect of all 6 h-oxacillin subMBC treated bacteria (≤ 1.42 Biofilm Formation Index (BFI); control = 0.6 BFI), whereas the strain 19606 reduced biofilm up to 1 BFI (control = 2 BFI). The antibiotic also reduced the exopolysaccharide production in almost all treated cells from both strains. The transformation efficiency (TE) of strain 19606 increased X̄ = 19 ± 11% more than the control by effect of all DNA and oxacillin conditions studied; however, the TE for strain 2093 was lower than the control. The expression of genes for resistance (bla-OXA), twitching (pilA/tonB) and swarming-like motilities (dat/ddc), and biofilm production (csuE) were altered by the oxacillin subMBC. Overall, exposure of oxacillinase-producing A. baumannii to oxacillin subMBC increases several virulence factors, representing a potential public health risk.
Additional Links: PMID-41102373
PubMed:
Citation:
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@article {pmid41102373,
year = {2025},
author = {Guerrero-López, F and Ortiz, Y and Merino-Mascorro, JÁ and Franco-Frías, E and García, S and Heredia, N},
title = {Subinhibitory Concentrations of Oxacillin Alter Motility, Biofilm Production, and Transformation Capability of the Oxacillinase-Producing Acinetobacter baumannii.},
journal = {Current microbiology},
volume = {82},
number = {12},
pages = {562},
pmid = {41102373},
issn = {1432-0991},
support = {A1-S-25033//Consejo Nacional de Ciencia y Tecnología/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Acinetobacter baumannii/drug effects/physiology/genetics/enzymology ; *Oxacillin/pharmacology ; *Anti-Bacterial Agents/pharmacology ; *beta-Lactamases/metabolism/genetics ; Bacterial Proteins/metabolism/genetics ; Microbial Sensitivity Tests ; *Transformation, Bacterial/drug effects ; Gene Expression Regulation, Bacterial/drug effects ; },
abstract = {Subinhibitory concentrations of various antibiotics can exacerbate microbial virulence. Acinetobacter baumannii is often resistant to oxacillin; however, the effect of low oxacillin concentrations on oxacillinase-producing bacteria remains unclear. Herein, oxacillinase producer A. baumannii ATCC-strains 2093 (motile) and 19606 (non-motile) were pre-exposed to sub-bactericidal concentrations (subMBC) of oxacillin (0.25, 0.5, and 1.0 mg/mL) and incubated at 37 °C. Growth kinetics, twitching and swarming-like motility, biofilm formation, exopolysaccharide production, transformation capability, and gene expression were determined. All oxacillin subMBC conditions exerted bacteriostatic effects in both strains. Pre-exposing the motile strain with 0.25 and 0.5 mg/mL of oxacillin for 1 h increased the twitching motility (4.2 ± 0.3 cm; control = 3.5 cm), whereas pre-exposure for 2 h it increased swarming-like motility (2.95 ± 0.15 cm; control = 2.7 cm). This strain also increased the biofilm production by effect of all 6 h-oxacillin subMBC treated bacteria (≤ 1.42 Biofilm Formation Index (BFI); control = 0.6 BFI), whereas the strain 19606 reduced biofilm up to 1 BFI (control = 2 BFI). The antibiotic also reduced the exopolysaccharide production in almost all treated cells from both strains. The transformation efficiency (TE) of strain 19606 increased X̄ = 19 ± 11% more than the control by effect of all DNA and oxacillin conditions studied; however, the TE for strain 2093 was lower than the control. The expression of genes for resistance (bla-OXA), twitching (pilA/tonB) and swarming-like motilities (dat/ddc), and biofilm production (csuE) were altered by the oxacillin subMBC. Overall, exposure of oxacillinase-producing A. baumannii to oxacillin subMBC increases several virulence factors, representing a potential public health risk.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Acinetobacter baumannii/drug effects/physiology/genetics/enzymology
*Oxacillin/pharmacology
*Anti-Bacterial Agents/pharmacology
*beta-Lactamases/metabolism/genetics
Bacterial Proteins/metabolism/genetics
Microbial Sensitivity Tests
*Transformation, Bacterial/drug effects
Gene Expression Regulation, Bacterial/drug effects
RevDate: 2025-10-16
Anti-biofilm and anti-infection activities of Lynronne-1 against major bovine mastitis pathogens.
Microbial pathogenesis pii:S0882-4010(25)00832-0 [Epub ahead of print].
Mastitis, an inflammatory condition affecting the udders of dairy cattle, is one of the most prevalent and costly diseases in the global dairy industry. This study investigated the efficacy of the antimicrobial peptide Lynronne-1 (lyn-1) against established biofilms formed by key mastitis-causing pathogens, including Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus chromogenes. A panel of 44 mastitis-associated bacterial strains comprising 25 Gram-positive and 19 Gram-negative species was screened for their biofilm-forming capacity, and seven strains were selected as representative targets to assess the ability of lyn-1 to prevent pathogen adhesion and invasion of bovine mammary alveolar cells (MAC-T). The minimal inhibitory concentration (MIC) of lyn-1 against polymicrobial cultures of the seven biofilm-forming strains was achieved at 128 μg/mL. On average, lyn-1 at 1x MIC reduced pre-formed biofilms of Gram-positive and Gram-negative strains by 22% and 11%, respectively. Lyn-1 significantly disrupted established biofilms of K. pneumoniae strain 160, S. aureus strains 184 and 186, and the polymicrobial culture (p < 0.05). Moreover, lyn-1 prevented or reduced new biofilm formation by already established biofilms in four out of seven tested strains (p < 0.05). Lyn-1 also significantly decreased (p < 0.05) both adhesion and invasion of the tested pathogens (n=7) to MAC-T cells at two multiplicities of infection of 1:1 and 1:100 (cell:bacteria). Fluorescence microscopy confirmed the specificity of the peptide by demonstrating its antibacterial activity without detectable damage to the MAC-T cell line, corroborating previous studies that reported lyn-1 to be non-cytotoxic to MAC-T cells at concentrations up to 256 μg/mL. These results illustrate that lyn-1 is effective against polymicrobial cultures of mastitis bacteria and shows promise as a targeted and safe agent for preventing and treating mastitis, particularly infections involving biofilm-forming Gram-positive bacteria.
Additional Links: PMID-41101662
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@article {pmid41101662,
year = {2025},
author = {Moreira, AJS and Araújo Domingues, KC and McClure, J and Camargo, KDV and Aulik, N and Oyama, LB and Huws, SA and Mantovani, HC},
title = {Anti-biofilm and anti-infection activities of Lynronne-1 against major bovine mastitis pathogens.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {108107},
doi = {10.1016/j.micpath.2025.108107},
pmid = {41101662},
issn = {1096-1208},
abstract = {Mastitis, an inflammatory condition affecting the udders of dairy cattle, is one of the most prevalent and costly diseases in the global dairy industry. This study investigated the efficacy of the antimicrobial peptide Lynronne-1 (lyn-1) against established biofilms formed by key mastitis-causing pathogens, including Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus chromogenes. A panel of 44 mastitis-associated bacterial strains comprising 25 Gram-positive and 19 Gram-negative species was screened for their biofilm-forming capacity, and seven strains were selected as representative targets to assess the ability of lyn-1 to prevent pathogen adhesion and invasion of bovine mammary alveolar cells (MAC-T). The minimal inhibitory concentration (MIC) of lyn-1 against polymicrobial cultures of the seven biofilm-forming strains was achieved at 128 μg/mL. On average, lyn-1 at 1x MIC reduced pre-formed biofilms of Gram-positive and Gram-negative strains by 22% and 11%, respectively. Lyn-1 significantly disrupted established biofilms of K. pneumoniae strain 160, S. aureus strains 184 and 186, and the polymicrobial culture (p < 0.05). Moreover, lyn-1 prevented or reduced new biofilm formation by already established biofilms in four out of seven tested strains (p < 0.05). Lyn-1 also significantly decreased (p < 0.05) both adhesion and invasion of the tested pathogens (n=7) to MAC-T cells at two multiplicities of infection of 1:1 and 1:100 (cell:bacteria). Fluorescence microscopy confirmed the specificity of the peptide by demonstrating its antibacterial activity without detectable damage to the MAC-T cell line, corroborating previous studies that reported lyn-1 to be non-cytotoxic to MAC-T cells at concentrations up to 256 μg/mL. These results illustrate that lyn-1 is effective against polymicrobial cultures of mastitis bacteria and shows promise as a targeted and safe agent for preventing and treating mastitis, particularly infections involving biofilm-forming Gram-positive bacteria.},
}
RevDate: 2025-10-16
Crude preparation of a phage-encoded biofilm-dispersing factor expressed in E. coli and its potential application in bacteriological analysis of environmental water samples.
Applied and environmental microbiology [Epub ahead of print].
A fundamental technical challenge in detecting pathogenic bacteria in aquatic reservoirs is the inability to accurately estimate biofilm-associated cells in water. Considering the role of biofilms in environmental persistence and waterborne transmission of bacterial pathogens, there is an increasing interest in substances that can effectively degrade bacterial biofilms. The biofilm-dispersing Vibrio cholerae phage JSF7 was analyzed by whole genome sequencing and found to carry a gene predicted to encode an enzyme for degrading complex polysaccharides. The gene was cloned in Escherichia coli DH5α, and crude extract from the recombinant E. coli enhanced the dispersion of diverse bacterial biofilms, including those of E. coli, Shigella dysenteriae, Pseudomonas aeruginosa, and V. cholerae. The crude extract was fully active at a temperature of 37°C and pH of 7.0 but was inactivated by proteinase-K treatment. Analysis of environmental water samples for the presence of V. cholerae O1 by enrichment culture detected significantly more V. cholerae O1-positive samples when the enrichment medium was supplemented with the extract, as compared with typical enrichment without the extract. These results suggest that a crude preparation of the phage-encoded biofilm-degrading factor expressed in E. coli has potential application in degrading bacterial biofilms and enhancing bacteriological analysis of water.IMPORTANCEIn their aquatic reservoirs, bacteria often exist as biofilms and are difficult to accurately detect by culturing water samples. Such biofilms have been implicated in waterborne transmission of pathogenic bacteria. We identified a bacteriophage that can disintegrate biofilms and disperse biofilm-associated bacteria. The putative phage gene responsible for this activity was cloned in an E. coli strain, and the crude cellular extract of the recombinant E. coli was found to promote dispersion of a variety of bacterial biofilms. Supplementation of bacterial growth medium with the crude extract also enhanced detection of V. cholerae O1, the causative agent of cholera in environmental water samples. The ability of a phage-derived biofilm-degrading factor to disperse diverse bacterial biofilms provides a novel approach for enhancing detection of waterborne bacterial pathogens in water beyond traditional enrichment methods.
Additional Links: PMID-41099554
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PubMed:
Citation:
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@article {pmid41099554,
year = {2025},
author = {Faruque, SN and Naser, IB and Hoque, MM and Akter, F and Faruque, SM},
title = {Crude preparation of a phage-encoded biofilm-dispersing factor expressed in E. coli and its potential application in bacteriological analysis of environmental water samples.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0116325},
doi = {10.1128/aem.01163-25},
pmid = {41099554},
issn = {1098-5336},
abstract = {A fundamental technical challenge in detecting pathogenic bacteria in aquatic reservoirs is the inability to accurately estimate biofilm-associated cells in water. Considering the role of biofilms in environmental persistence and waterborne transmission of bacterial pathogens, there is an increasing interest in substances that can effectively degrade bacterial biofilms. The biofilm-dispersing Vibrio cholerae phage JSF7 was analyzed by whole genome sequencing and found to carry a gene predicted to encode an enzyme for degrading complex polysaccharides. The gene was cloned in Escherichia coli DH5α, and crude extract from the recombinant E. coli enhanced the dispersion of diverse bacterial biofilms, including those of E. coli, Shigella dysenteriae, Pseudomonas aeruginosa, and V. cholerae. The crude extract was fully active at a temperature of 37°C and pH of 7.0 but was inactivated by proteinase-K treatment. Analysis of environmental water samples for the presence of V. cholerae O1 by enrichment culture detected significantly more V. cholerae O1-positive samples when the enrichment medium was supplemented with the extract, as compared with typical enrichment without the extract. These results suggest that a crude preparation of the phage-encoded biofilm-degrading factor expressed in E. coli has potential application in degrading bacterial biofilms and enhancing bacteriological analysis of water.IMPORTANCEIn their aquatic reservoirs, bacteria often exist as biofilms and are difficult to accurately detect by culturing water samples. Such biofilms have been implicated in waterborne transmission of pathogenic bacteria. We identified a bacteriophage that can disintegrate biofilms and disperse biofilm-associated bacteria. The putative phage gene responsible for this activity was cloned in an E. coli strain, and the crude cellular extract of the recombinant E. coli was found to promote dispersion of a variety of bacterial biofilms. Supplementation of bacterial growth medium with the crude extract also enhanced detection of V. cholerae O1, the causative agent of cholera in environmental water samples. The ability of a phage-derived biofilm-degrading factor to disperse diverse bacterial biofilms provides a novel approach for enhancing detection of waterborne bacterial pathogens in water beyond traditional enrichment methods.},
}
RevDate: 2025-10-16
Forging biofilms: metal-induced microbial responses in biofilm formation.
Journal of bacteriology [Epub ahead of print].
Biofilms are a major contributor to antibiotic resistance and persistence in hospital environments. These bacterial communities form protective structures that shield microbes from various stressors, such as oxidative stress, pH fluctuations, osmotic pressure, and nutrient deprivation. As our understanding of biofilms has grown, it has become evident that metals play a crucial role in several aspects of biofilm biology. Metals are involved in regulating biofilm formation, facilitating communication and competition among bacteria, and supporting the structural integrity and adherence of bacterial cells within the biofilm. This review discusses the complex relationship between metals and biofilms during bacterial pathogenesis to emphasize how the availability of metals influences biofilm dynamics. We explore mechanisms through which metals impact biofilm architecture and resilience, as well as the ability of bacteria to evade host immune defenses and outcompete other microbes. In polymicrobial environments, some bacteria use metals to collaborate with other microbes within the biofilm, whereas others deprive neighboring microbes of essential metals to dominate the biofilm community. Additionally, metals have roles beyond their nutritional value, where they can promote the integrity and stability of biofilms. By understanding these interactions, researchers can gain valuable insights into the significance of metals in biofilm-associated infections. This knowledge can help identify potential therapeutic targets that will lead to the development of new strategies to combat biofilm-related infections and improve patient outcomes.
Additional Links: PMID-41099530
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PubMed:
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@article {pmid41099530,
year = {2025},
author = {Price, SL and Skaar, EP},
title = {Forging biofilms: metal-induced microbial responses in biofilm formation.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {e0024725},
doi = {10.1128/jb.00247-25},
pmid = {41099530},
issn = {1098-5530},
abstract = {Biofilms are a major contributor to antibiotic resistance and persistence in hospital environments. These bacterial communities form protective structures that shield microbes from various stressors, such as oxidative stress, pH fluctuations, osmotic pressure, and nutrient deprivation. As our understanding of biofilms has grown, it has become evident that metals play a crucial role in several aspects of biofilm biology. Metals are involved in regulating biofilm formation, facilitating communication and competition among bacteria, and supporting the structural integrity and adherence of bacterial cells within the biofilm. This review discusses the complex relationship between metals and biofilms during bacterial pathogenesis to emphasize how the availability of metals influences biofilm dynamics. We explore mechanisms through which metals impact biofilm architecture and resilience, as well as the ability of bacteria to evade host immune defenses and outcompete other microbes. In polymicrobial environments, some bacteria use metals to collaborate with other microbes within the biofilm, whereas others deprive neighboring microbes of essential metals to dominate the biofilm community. Additionally, metals have roles beyond their nutritional value, where they can promote the integrity and stability of biofilms. By understanding these interactions, researchers can gain valuable insights into the significance of metals in biofilm-associated infections. This knowledge can help identify potential therapeutic targets that will lead to the development of new strategies to combat biofilm-related infections and improve patient outcomes.},
}
RevDate: 2025-10-16
Correction: Ultrathin DNA-copper nanosheets with antibacterial and anti-biofilm activity for treatment of infected wounds.
Correction for 'Ultrathin DNA-copper nanosheets with antibacterial and anti-biofilm activity for treatment of infected wounds' by Fangfang Chen et al., Nanoscale Horiz., 2025, https://doi.org/10.1039/d5nh00257e.
Additional Links: PMID-41099454
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PubMed:
Citation:
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@article {pmid41099454,
year = {2025},
author = {Chen, F and Lei, M and Luo, J and Li, J and Wang, J and Zhang, N and Li, X and Jia, N and Ouyang, X and Bu, H},
title = {Correction: Ultrathin DNA-copper nanosheets with antibacterial and anti-biofilm activity for treatment of infected wounds.},
journal = {Nanoscale horizons},
volume = {},
number = {},
pages = {},
doi = {10.1039/d5nh90062j},
pmid = {41099454},
issn = {2055-6764},
abstract = {Correction for 'Ultrathin DNA-copper nanosheets with antibacterial and anti-biofilm activity for treatment of infected wounds' by Fangfang Chen et al., Nanoscale Horiz., 2025, https://doi.org/10.1039/d5nh00257e.},
}
RevDate: 2025-10-16
CmpDate: 2025-10-16
Prevalence of algD, pslD, and pelF Genes Involved in Biofilm Formation in Clinical MDR Pseudomonas aeruginosa Strains.
Iranian journal of pathology, 20(4):380-385.
BACKGROUND & OBJECTIVE: The purpose of this research was to determine the frequency of algD, pslD, and pelF genes in biofilm formation among MDR and non-MDR clinical strains of Pseudomonas aeruginosa in Khorramabad, Iran (2024).
METHODS: This cross-sectional study included all Pseudomonas aeruginosa isolates collected from various clinical samples in Khorramabad teaching hospitals in 2024. After confirming the isolates and determining their antibiotic resistance patterns using the disc diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, algD, pelF, and pslD genes were detected by PCR.
RESULTS: The highest sensitivity was observed to imipenem (75%) and meropenem (71.3%), while the greatest resistance was recorded against ciprofloxacin, ceftazidime, and tobramycin 45 (56.25%). The frequencies of the algD, pelF, and pslD genes were 88.8, 76.3, and 96.3%, respectively. A significant association was found between the PelF and algD genes with multidrug resistance (MDR) (P<0.05).
CONCLUSION: The presence of multi-drug resistance (MDR) in this study indicates the need for serious measures to control infections caused by this bacterium. Further research is recommended to explore the contribution of biofilm-associated genes to the development of multi-drug resistance (MDR).
Additional Links: PMID-41099047
PubMed:
Citation:
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@article {pmid41099047,
year = {2025},
author = {Haghighatian, Z and Shirani, N and Goudarzi, G and Shakib, P and Jahani, F and Zare, S},
title = {Prevalence of algD, pslD, and pelF Genes Involved in Biofilm Formation in Clinical MDR Pseudomonas aeruginosa Strains.},
journal = {Iranian journal of pathology},
volume = {20},
number = {4},
pages = {380-385},
pmid = {41099047},
issn = {1735-5303},
abstract = {BACKGROUND & OBJECTIVE: The purpose of this research was to determine the frequency of algD, pslD, and pelF genes in biofilm formation among MDR and non-MDR clinical strains of Pseudomonas aeruginosa in Khorramabad, Iran (2024).
METHODS: This cross-sectional study included all Pseudomonas aeruginosa isolates collected from various clinical samples in Khorramabad teaching hospitals in 2024. After confirming the isolates and determining their antibiotic resistance patterns using the disc diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, algD, pelF, and pslD genes were detected by PCR.
RESULTS: The highest sensitivity was observed to imipenem (75%) and meropenem (71.3%), while the greatest resistance was recorded against ciprofloxacin, ceftazidime, and tobramycin 45 (56.25%). The frequencies of the algD, pelF, and pslD genes were 88.8, 76.3, and 96.3%, respectively. A significant association was found between the PelF and algD genes with multidrug resistance (MDR) (P<0.05).
CONCLUSION: The presence of multi-drug resistance (MDR) in this study indicates the need for serious measures to control infections caused by this bacterium. Further research is recommended to explore the contribution of biofilm-associated genes to the development of multi-drug resistance (MDR).},
}
RevDate: 2025-10-16
Mobile organic biofilm process for ammonia removal under low solids retention time and low operating temperature conditions.
Environmental technology [Epub ahead of print].
This study aimed to evaluate the effectiveness of mobile organic biofilm (MOB) technology for removing ammonia (NH3/NH4[+], referred to as NH4[+]) from wastewater in low solids retention time (SRT) and low operating temperature conditions. The MOB technology is based on process intensification using a plant-based media (milled kenaf) to develop a mobile organic biofilm. In the MOB process, media is added to the aeration tanks of an activated sludge process. Two bench-scale sequencing batch reactors (SBRs) with 1.5 L volume were used to assess MOB technology, a control, and a MOB-added reactor, hereafter the MOB reactor. The NH4[+] concentration in the influent ranged from 5.5 to 14.9 mg N/L, with an average of 10.1 mg N/L over the study period. The COD level varied from 66.0 to 94.0 mg/L, with an average of 78.8 mg/L. The results showed that the MOB process effectively removes NH4[+] and COD with a three-day SRT at 12 °C. The MOB reactor achieved an average of 93.1% NH4[+] and over 47% COD removal throughout the stable operation period. MOB represents a promising wastewater treatment technology for the removal of nitrogen in activated sludge facilities.
Additional Links: PMID-41098000
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PubMed:
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@article {pmid41098000,
year = {2025},
author = {Calda, B and Figdore, B and Corey, C and Hendricks, A and McKelvey, S and Metch, J and Duran, M},
title = {Mobile organic biofilm process for ammonia removal under low solids retention time and low operating temperature conditions.},
journal = {Environmental technology},
volume = {},
number = {},
pages = {1-10},
doi = {10.1080/09593330.2025.2572542},
pmid = {41098000},
issn = {1479-487X},
abstract = {This study aimed to evaluate the effectiveness of mobile organic biofilm (MOB) technology for removing ammonia (NH3/NH4[+], referred to as NH4[+]) from wastewater in low solids retention time (SRT) and low operating temperature conditions. The MOB technology is based on process intensification using a plant-based media (milled kenaf) to develop a mobile organic biofilm. In the MOB process, media is added to the aeration tanks of an activated sludge process. Two bench-scale sequencing batch reactors (SBRs) with 1.5 L volume were used to assess MOB technology, a control, and a MOB-added reactor, hereafter the MOB reactor. The NH4[+] concentration in the influent ranged from 5.5 to 14.9 mg N/L, with an average of 10.1 mg N/L over the study period. The COD level varied from 66.0 to 94.0 mg/L, with an average of 78.8 mg/L. The results showed that the MOB process effectively removes NH4[+] and COD with a three-day SRT at 12 °C. The MOB reactor achieved an average of 93.1% NH4[+] and over 47% COD removal throughout the stable operation period. MOB represents a promising wastewater treatment technology for the removal of nitrogen in activated sludge facilities.},
}
RevDate: 2025-10-16
CmpDate: 2025-10-16
Effects of Nutritional Conditions on Growth, Biofilm Formation, and Enterotoxin Production in Staphylococcus aureus Associated with Food Poisoning.
International journal of molecular sciences, 26(19): pii:ijms26199791.
Staphylococcal food poisoning (SFP) is a common foodborne illness caused by the ingestion of enterotoxins produced by Staphylococcus aureus, posing a persistent global public health concern. Although regional differences in implicated food types and predominant enterotoxins have been reported, the underlying factors remain unclear. In this study, we systematically investigated the effects of nutritional factors on the growth, biofilm formation, and production of two representative enterotoxins, SEA and SEB, by S. aureus. Specifically, we evaluated bacterial responses to different concentrations of NaCl, glucose, and tryptone. NaCl suppressed growth, biofilm formation and enterotoxin production in a dose-dependent manner. Glucose markedly inhibited both bacteria growth and enterotoxin production, with a stronger effect on SEB than SEA. In contrast, tryptone promoted bacterial growth and moderately enhanced biofilm formation but did not significantly affect enterotoxin production. Importantly, even under comparable bacterial counts, the types and amounts of SEs produced varied substantially depending on the nutrient composition. These findings provide new insights into the nutrient-dependent regulation of virulence in S. aureus and highlight the importance of considering environmental and nutritional factors when assessing risks of SFP and designing effective food safety strategies.
Additional Links: PMID-41097057
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PubMed:
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@article {pmid41097057,
year = {2025},
author = {Hu, Z and Zhu, Z and Ono, HK and Hirose, S and Hara-Kudo, Y and Li, S and Hu, DL},
title = {Effects of Nutritional Conditions on Growth, Biofilm Formation, and Enterotoxin Production in Staphylococcus aureus Associated with Food Poisoning.},
journal = {International journal of molecular sciences},
volume = {26},
number = {19},
pages = {},
doi = {10.3390/ijms26199791},
pmid = {41097057},
issn = {1422-0067},
support = {(B) JP21H02371 (D-L.H) and (B) JP23K21279 (D-L.H).//JSPS KAKENHI Grant-in-Aid for Scientific Research/ ; },
mesh = {*Biofilms/growth & development/drug effects ; *Staphylococcus aureus/growth & development/physiology/metabolism/drug effects ; *Enterotoxins/biosynthesis/metabolism ; *Staphylococcal Food Poisoning/microbiology ; Humans ; Glucose/pharmacology ; Sodium Chloride/pharmacology ; *Foodborne Diseases/microbiology ; Peptones/pharmacology ; Food Microbiology ; },
abstract = {Staphylococcal food poisoning (SFP) is a common foodborne illness caused by the ingestion of enterotoxins produced by Staphylococcus aureus, posing a persistent global public health concern. Although regional differences in implicated food types and predominant enterotoxins have been reported, the underlying factors remain unclear. In this study, we systematically investigated the effects of nutritional factors on the growth, biofilm formation, and production of two representative enterotoxins, SEA and SEB, by S. aureus. Specifically, we evaluated bacterial responses to different concentrations of NaCl, glucose, and tryptone. NaCl suppressed growth, biofilm formation and enterotoxin production in a dose-dependent manner. Glucose markedly inhibited both bacteria growth and enterotoxin production, with a stronger effect on SEB than SEA. In contrast, tryptone promoted bacterial growth and moderately enhanced biofilm formation but did not significantly affect enterotoxin production. Importantly, even under comparable bacterial counts, the types and amounts of SEs produced varied substantially depending on the nutrient composition. These findings provide new insights into the nutrient-dependent regulation of virulence in S. aureus and highlight the importance of considering environmental and nutritional factors when assessing risks of SFP and designing effective food safety strategies.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development/drug effects
*Staphylococcus aureus/growth & development/physiology/metabolism/drug effects
*Enterotoxins/biosynthesis/metabolism
*Staphylococcal Food Poisoning/microbiology
Humans
Glucose/pharmacology
Sodium Chloride/pharmacology
*Foodborne Diseases/microbiology
Peptones/pharmacology
Food Microbiology
RevDate: 2025-10-16
CmpDate: 2025-10-16
Asiatic Acid Disrupts the Biofilm Virulence of Streptococcus mutans by Transcriptional Reprogramming of Quorum Sensing System.
International journal of molecular sciences, 26(19): pii:ijms26199510.
Dental caries, a prevalent biofilm-mediated chronic disease, causes enamel demineralization, pulp infection, and systemic complications. Dental plaque biofilm is the initiating factor for the occurrence and development of caries. Streptococcus mutans is an opportunistic pathogen linked to the structure and ecology of dental plaque biofilms. The molecular mechanism of S. mutans during biofilm ontogeny in driving cariogenesis has been extensively elucidated. Here, we observed that asiatic acid is a potent biofilm disruptor that selectively dismantles S. mutans biofilm architectures, prompting us to investigate its mechanism. The minimum biofilm inhibition concentration (MBIC) of asiatic acid on S. mutans was 62.5 μM, but the MBIC level did not substantially impede planktonic growth. Using the static active-attachment model, it was demonstrated that asiatic acid significantly reduced biofilm biomass (p < 0.001) and extracellular polysaccharides (EPS) content (p < 0.001), while concurrently diminishing acid production (p = 0.017) and metabolic activity (p = 0.014). Confocal and scanning electron microscopy further confirmed structural disintegration, including bacterial detachment and reduced biofilm thickness. Transcriptome analysis of S. mutans biofilm treated with asiatic acid revealed 454 differentially expressed genes (adjusted p < 0.05, |log2FC| ≥ 1). Notably, genes related to the CiaRH two-component system (ciaR, ciaH), a central regulatory hub for biofilm maturation and acid tolerance. This disruption initiates a downstream cascade, causing a coordinated downregulation of critical gene clusters essential for virulence and pathogenesis, including stress response (htrA, clpP, groEL, dnaK), and the glucan-binding protein gene (gbpC) essential for biofilm structural integrity. These findings provide the first mechanistic evidence linking asiatic acid to transcriptional reprogramming in S. mutans biofilm, offering a novel ecological strategy for caries prevention by targeting key regulatory pathways.
Additional Links: PMID-41096777
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PubMed:
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@article {pmid41096777,
year = {2025},
author = {Shi, Q and Li, F and Peng, Y and Sun, Q and Zhao, H and Lu, F and Zhao, H},
title = {Asiatic Acid Disrupts the Biofilm Virulence of Streptococcus mutans by Transcriptional Reprogramming of Quorum Sensing System.},
journal = {International journal of molecular sciences},
volume = {26},
number = {19},
pages = {},
doi = {10.3390/ijms26199510},
pmid = {41096777},
issn = {1422-0067},
support = {32402248//National Natural Science Foundation of China/ ; No. 24JCQNJC00880//Natural Science Foundation of Tianjin/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Streptococcus mutans/drug effects/pathogenicity/genetics/physiology ; *Quorum Sensing/drug effects/genetics ; *Pentacyclic Triterpenes/pharmacology ; Gene Expression Regulation, Bacterial/drug effects ; Virulence/drug effects/genetics ; Dental Caries/microbiology ; Humans ; Bacterial Proteins/genetics/metabolism ; Gene Expression Profiling ; },
abstract = {Dental caries, a prevalent biofilm-mediated chronic disease, causes enamel demineralization, pulp infection, and systemic complications. Dental plaque biofilm is the initiating factor for the occurrence and development of caries. Streptococcus mutans is an opportunistic pathogen linked to the structure and ecology of dental plaque biofilms. The molecular mechanism of S. mutans during biofilm ontogeny in driving cariogenesis has been extensively elucidated. Here, we observed that asiatic acid is a potent biofilm disruptor that selectively dismantles S. mutans biofilm architectures, prompting us to investigate its mechanism. The minimum biofilm inhibition concentration (MBIC) of asiatic acid on S. mutans was 62.5 μM, but the MBIC level did not substantially impede planktonic growth. Using the static active-attachment model, it was demonstrated that asiatic acid significantly reduced biofilm biomass (p < 0.001) and extracellular polysaccharides (EPS) content (p < 0.001), while concurrently diminishing acid production (p = 0.017) and metabolic activity (p = 0.014). Confocal and scanning electron microscopy further confirmed structural disintegration, including bacterial detachment and reduced biofilm thickness. Transcriptome analysis of S. mutans biofilm treated with asiatic acid revealed 454 differentially expressed genes (adjusted p < 0.05, |log2FC| ≥ 1). Notably, genes related to the CiaRH two-component system (ciaR, ciaH), a central regulatory hub for biofilm maturation and acid tolerance. This disruption initiates a downstream cascade, causing a coordinated downregulation of critical gene clusters essential for virulence and pathogenesis, including stress response (htrA, clpP, groEL, dnaK), and the glucan-binding protein gene (gbpC) essential for biofilm structural integrity. These findings provide the first mechanistic evidence linking asiatic acid to transcriptional reprogramming in S. mutans biofilm, offering a novel ecological strategy for caries prevention by targeting key regulatory pathways.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Streptococcus mutans/drug effects/pathogenicity/genetics/physiology
*Quorum Sensing/drug effects/genetics
*Pentacyclic Triterpenes/pharmacology
Gene Expression Regulation, Bacterial/drug effects
Virulence/drug effects/genetics
Dental Caries/microbiology
Humans
Bacterial Proteins/genetics/metabolism
Gene Expression Profiling
RevDate: 2025-10-15
CmpDate: 2025-10-15
Investigation of shockwave treatment for disruption of bacterial biofilm on tubular structure.
Scientific reports, 15(1):36041.
Biofilms, which are structures formed by microorganisms, are protected by extracellular polymeric substances (EPS) secreted by bacteria against external threats, including antibiotics. The current study aims to assess the effects of shockwave treatment combined with antibiotic therapy on Pseudomonas aeruginosa biofilms in tubular structures in vitro. The biofilms were formed on the inner surfaces of silicone tubes for three days under dynamic conditions. The biofilms were treated with shockwave treatment (120 pulses at 2 Hz), followed by exposure to 4 µg/ml ciprofloxacin for 6 h. Bacterial viability was assessed using colony-forming unit (CFU) and confocal laser scanning microscopy (CLSM) with SYTO9/PI staining, while biofilm detachment was evaluated via crystal violet (CV) staining and scanning electron microscopy (SEM). According to the SEM and CFU analysis, the shockwave and antibiotic-combined treatment significantly detached the biofilm, removing up to 97.5% of the surface area and decreased bacterial viability by 40%, compared to untreated control biofilms. The CV staining showed a significant reduction in biofilm biomass to an OD600 of 0.14. The CLSM analysis revealed a dead bacteria proportion of 67%. In conclusion, the shockwave treatment combined with antibiotics could effectively degrade the biofilms in tubular structures and enhance antibiotic efficacy.
Additional Links: PMID-41094089
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@article {pmid41094089,
year = {2025},
author = {Jo, J and Stadler, S and Costandi, P and Hasenberg, T and Kang, HW},
title = {Investigation of shockwave treatment for disruption of bacterial biofilm on tubular structure.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {36041},
pmid = {41094089},
issn = {2045-2322},
support = {RS-2021-NR060118//Ministry of Education/ ; },
mesh = {*Biofilms/drug effects/radiation effects/growth & development ; *Pseudomonas aeruginosa/drug effects/physiology/radiation effects ; *Anti-Bacterial Agents/pharmacology ; Microbial Viability/drug effects/radiation effects ; Ciprofloxacin/pharmacology ; Microscopy, Electron, Scanning ; *High-Energy Shock Waves ; Microscopy, Confocal ; },
abstract = {Biofilms, which are structures formed by microorganisms, are protected by extracellular polymeric substances (EPS) secreted by bacteria against external threats, including antibiotics. The current study aims to assess the effects of shockwave treatment combined with antibiotic therapy on Pseudomonas aeruginosa biofilms in tubular structures in vitro. The biofilms were formed on the inner surfaces of silicone tubes for three days under dynamic conditions. The biofilms were treated with shockwave treatment (120 pulses at 2 Hz), followed by exposure to 4 µg/ml ciprofloxacin for 6 h. Bacterial viability was assessed using colony-forming unit (CFU) and confocal laser scanning microscopy (CLSM) with SYTO9/PI staining, while biofilm detachment was evaluated via crystal violet (CV) staining and scanning electron microscopy (SEM). According to the SEM and CFU analysis, the shockwave and antibiotic-combined treatment significantly detached the biofilm, removing up to 97.5% of the surface area and decreased bacterial viability by 40%, compared to untreated control biofilms. The CV staining showed a significant reduction in biofilm biomass to an OD600 of 0.14. The CLSM analysis revealed a dead bacteria proportion of 67%. In conclusion, the shockwave treatment combined with antibiotics could effectively degrade the biofilms in tubular structures and enhance antibiotic efficacy.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/radiation effects/growth & development
*Pseudomonas aeruginosa/drug effects/physiology/radiation effects
*Anti-Bacterial Agents/pharmacology
Microbial Viability/drug effects/radiation effects
Ciprofloxacin/pharmacology
Microscopy, Electron, Scanning
*High-Energy Shock Waves
Microscopy, Confocal
RevDate: 2025-10-15
Biofilm-engineered nitrite transfer channeling from comammox to anammox drives autotrophic nitrogen removal in low-strength municipal wastewater.
Journal of environmental management, 394:127621 pii:S0301-4797(25)03597-2 [Epub ahead of print].
The discovery of complete ammonia oxidation (comammox) bacteria has challenged traditional paradigms. Previous studies often assumed that comammox proliferation could be detrimental to anammox-based systems, recent research has demonstrated their potential for mutualistic synergy in nitrogen removal. While research on these coupled systems has commenced, there is still a lack of accurate assessment regarding the nitrogen removal contributions of the organisms involved, particularly comammox and AOB. Additionally, the appropriate reactor configuration and operating conditions remain to be clarified. Here, we successfully established a comammox-driven nitritation coupled with anammox in a completely autotrophic biofilm system. The reactor achieved 80 % and 93 % TN and NH4[+]-N removal under favorable hydraulic loading conditions (HRT: 6h) and superior intermittent aeration (DO: 0.34 mg/L). The weakly acidic, micro-oxygenated biofilm environment fostered a conducive ecological niche for the core consortium. Genetic quantification and selective inhibition assays robustly assessed the nitritation role of comammox. Stronger amoA gene expression and higher ammonia oxidation contribution (33.6 %) compared to AOB (19.4 %) fully confirmed the synergistic relationship between comammox and anammox. The reconstructed metabolic interactions, inferred based on amplicon sequencing data, revealed the optimized mechanism of "functional bacterial specialization, metabolic complementation, and electron transfer" in this unique system. Our results present novel perspectives into the collaborative nutrients removal by comammox-anammox, which could contribute to reshaping nitrogen cycle management in conventional engineering and developing innovative wastewater treatment processes.
Additional Links: PMID-41092884
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PubMed:
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@article {pmid41092884,
year = {2025},
author = {Jin, D and Zhao, R and Zhang, X and Zhang, X and Wu, P},
title = {Biofilm-engineered nitrite transfer channeling from comammox to anammox drives autotrophic nitrogen removal in low-strength municipal wastewater.},
journal = {Journal of environmental management},
volume = {394},
number = {},
pages = {127621},
doi = {10.1016/j.jenvman.2025.127621},
pmid = {41092884},
issn = {1095-8630},
abstract = {The discovery of complete ammonia oxidation (comammox) bacteria has challenged traditional paradigms. Previous studies often assumed that comammox proliferation could be detrimental to anammox-based systems, recent research has demonstrated their potential for mutualistic synergy in nitrogen removal. While research on these coupled systems has commenced, there is still a lack of accurate assessment regarding the nitrogen removal contributions of the organisms involved, particularly comammox and AOB. Additionally, the appropriate reactor configuration and operating conditions remain to be clarified. Here, we successfully established a comammox-driven nitritation coupled with anammox in a completely autotrophic biofilm system. The reactor achieved 80 % and 93 % TN and NH4[+]-N removal under favorable hydraulic loading conditions (HRT: 6h) and superior intermittent aeration (DO: 0.34 mg/L). The weakly acidic, micro-oxygenated biofilm environment fostered a conducive ecological niche for the core consortium. Genetic quantification and selective inhibition assays robustly assessed the nitritation role of comammox. Stronger amoA gene expression and higher ammonia oxidation contribution (33.6 %) compared to AOB (19.4 %) fully confirmed the synergistic relationship between comammox and anammox. The reconstructed metabolic interactions, inferred based on amplicon sequencing data, revealed the optimized mechanism of "functional bacterial specialization, metabolic complementation, and electron transfer" in this unique system. Our results present novel perspectives into the collaborative nutrients removal by comammox-anammox, which could contribute to reshaping nitrogen cycle management in conventional engineering and developing innovative wastewater treatment processes.},
}
RevDate: 2025-10-15
Human cell-derived extracellular vesicles exhibit anti-biofilm effects against Pseudomonas aeruginosa.
FEMS microbiology letters pii:8285811 [Epub ahead of print].
The need for new antimicrobial approaches is one of the most pressing concerns in modern medicine. A particular pathogen of concern is multidrug resistant Pseudomonas aeruginosa, which is responsible for over 32,000 infections in the US yearly. One potential class of novel antimicrobials is extracellular vesicles (EVs), which have been found to have intrinsic antimicrobial and anti-virulence properties. Here, the antimicrobial activity of EVs on P. aeruginosa was explored in the context of biofilms of hyper-virulent strain PA14. We identified the human monocyte cell line THP-1 as a promising source of EVs for this application, inducing reduced PA14 biofilm formation in a dose-dependent manner. THP-1 EVs were not found to affect P. aeruginosa growth planktonically within the biofilm assay or in shaken culture. Additionally, we demonstrate that anti-biofilm effects were conserved with similar efficacy across THP-1 monocyte and differentiated THP-1 macrophage-derived EVs. Further, EVs from induced pluripotent stem cell-derived mesenchymal stem/stromal cells (iMSCs) also reduced PA14 biofilm formation to a similar extent as THP-1 EVs, while EVs from human embryonic kidney cells (HEK293T) had a similar effect to its media control. This work indicates that human cell-derived EVs from several sources possess biological and/or physical properties that reduce PA14 biofilm formation.
Additional Links: PMID-41091848
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PubMed:
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@article {pmid41091848,
year = {2025},
author = {Solomon, TJ and Byrne, CM and Boledovic, SS and Flumen, EJ and Pirolli, NH and Powsner, EH and Jay, SM},
title = {Human cell-derived extracellular vesicles exhibit anti-biofilm effects against Pseudomonas aeruginosa.},
journal = {FEMS microbiology letters},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsle/fnaf111},
pmid = {41091848},
issn = {1574-6968},
abstract = {The need for new antimicrobial approaches is one of the most pressing concerns in modern medicine. A particular pathogen of concern is multidrug resistant Pseudomonas aeruginosa, which is responsible for over 32,000 infections in the US yearly. One potential class of novel antimicrobials is extracellular vesicles (EVs), which have been found to have intrinsic antimicrobial and anti-virulence properties. Here, the antimicrobial activity of EVs on P. aeruginosa was explored in the context of biofilms of hyper-virulent strain PA14. We identified the human monocyte cell line THP-1 as a promising source of EVs for this application, inducing reduced PA14 biofilm formation in a dose-dependent manner. THP-1 EVs were not found to affect P. aeruginosa growth planktonically within the biofilm assay or in shaken culture. Additionally, we demonstrate that anti-biofilm effects were conserved with similar efficacy across THP-1 monocyte and differentiated THP-1 macrophage-derived EVs. Further, EVs from induced pluripotent stem cell-derived mesenchymal stem/stromal cells (iMSCs) also reduced PA14 biofilm formation to a similar extent as THP-1 EVs, while EVs from human embryonic kidney cells (HEK293T) had a similar effect to its media control. This work indicates that human cell-derived EVs from several sources possess biological and/or physical properties that reduce PA14 biofilm formation.},
}
RevDate: 2025-10-15
Probiotic-Derived Bacteriocins for Veterinary Biofilm Control: Mechanisms, Evidence, and One Health Translation.
Probiotics and antimicrobial proteins [Epub ahead of print].
Biofilm-related infections pose a critical challenge in veterinary medicine, driving antimicrobial resistance (AMR) and undermining livestock, poultry, and aquaculture productivity. Conventional antibiotics are often ineffective against biofilms, highlighting the need for novel alternatives. Bacteriocins, ribosomally synthesized antimicrobial peptides produced mainly by lactic acid bacteria, offer broad-spectrum activity, stability, and minimal cytotoxicity. This review outlines their multifaceted mechanisms, ranging from inhibition of microbial adhesion and quorum sensing to disruption of membranes and extracellular matrices, which make them promising tools against biofilm-forming pathogens. Evidence across veterinary sectors demonstrates their potential to mitigate mastitis, swine enteric diseases, poultry colibacillosis, and aquaculture infections. Synergistic applications with antibiotics, nanoparticles, and other antimicrobials further enhance efficacy and reduce antibiotic dependence. This article critically synthesizes cross-sector evidence from livestock, poultry, and aquaculture while also introducing a unique mechanistic classification of bacteriocin action against biofilms. By integrating veterinary and One Health perspectives, it highlights translational gaps and practical pathways that have not been systematically addressed before. However, translation into practice remains limited by the absence of standardized biofilm models, insufficient in vivo validation, gaps in pharmacokinetics, and scarce farm-level trials. A structured pipeline from discovery to commercialization, embedded within the One Health framework, will be essential to advance bacteriocins as sustainable biotherapeutics for veterinary and public health.
Additional Links: PMID-41091404
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Citation:
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@article {pmid41091404,
year = {2025},
author = {Khalid, MH and Farooq, F and Aslam, B and Saria, M},
title = {Probiotic-Derived Bacteriocins for Veterinary Biofilm Control: Mechanisms, Evidence, and One Health Translation.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {41091404},
issn = {1867-1314},
abstract = {Biofilm-related infections pose a critical challenge in veterinary medicine, driving antimicrobial resistance (AMR) and undermining livestock, poultry, and aquaculture productivity. Conventional antibiotics are often ineffective against biofilms, highlighting the need for novel alternatives. Bacteriocins, ribosomally synthesized antimicrobial peptides produced mainly by lactic acid bacteria, offer broad-spectrum activity, stability, and minimal cytotoxicity. This review outlines their multifaceted mechanisms, ranging from inhibition of microbial adhesion and quorum sensing to disruption of membranes and extracellular matrices, which make them promising tools against biofilm-forming pathogens. Evidence across veterinary sectors demonstrates their potential to mitigate mastitis, swine enteric diseases, poultry colibacillosis, and aquaculture infections. Synergistic applications with antibiotics, nanoparticles, and other antimicrobials further enhance efficacy and reduce antibiotic dependence. This article critically synthesizes cross-sector evidence from livestock, poultry, and aquaculture while also introducing a unique mechanistic classification of bacteriocin action against biofilms. By integrating veterinary and One Health perspectives, it highlights translational gaps and practical pathways that have not been systematically addressed before. However, translation into practice remains limited by the absence of standardized biofilm models, insufficient in vivo validation, gaps in pharmacokinetics, and scarce farm-level trials. A structured pipeline from discovery to commercialization, embedded within the One Health framework, will be essential to advance bacteriocins as sustainable biotherapeutics for veterinary and public health.},
}
RevDate: 2025-10-15
CmpDate: 2025-10-15
Biofilm Control Activity of Triphenylphosphonium-Conjugated Curcumin Against Staphylococcus aureus.
APMIS : acta pathologica, microbiologica, et immunologica Scandinavica, 133(10):e70075.
Hospital- and community-acquired Staphylococcus aureus infections are dominated by their biofilms and cause difficult-to-treat persistent infections. As an alternative anti-biofilm agent, the efficacy of triphenylphosphonium (TPP)-conjugated curcumin (TPP-curcumin) was determined against S. aureus biofilms in comparison to that of curcumin and commercial antibiotics. TPP-curcumin elicited strong anti-staphylococcal activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 3.125 and 6.25 μM, respectively. The MIC and MBC values for curcumin and ampicillin were > 125 and > 286.2 μM (100 μg/mL), respectively. The MIC and MBC values were 25.7 μM (12.5 μg/mL) and 103 μM (50 μg/mL), respectively, for kanamycin. TPP-curcumin was multi-fold more effective than curcumin in inhibiting biofilm growth. Minimum biofilm inhibitory concentration (MBIC) values of TPP-curcumin, curcumin, ampicillin and kanamycin were 3.125, > 125, > 286 and 25 μM, respectively. Besides inhibiting biofilm formation, TPP-curcumin has effectively killed S. aureus cells in pre-formed or established biofilms. Treatment of biofilms with 25 μM TPP-curcumin achieved near-complete cell killing. Exposure to TPP-curcumin led to severe membrane damage and oxidative stress in S. aureus cells. The strong antimicrobial and antibiofilm activity of TPP-curcumin suggests its potential use for developing or augmenting antibacterial therapies for drug-resistant S. aureus infections.
Additional Links: PMID-41090445
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PubMed:
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@article {pmid41090445,
year = {2025},
author = {Reddy, GKK and Babu, AZ and Kutala, VK and Sandur, SK and Nancharaiah, YV},
title = {Biofilm Control Activity of Triphenylphosphonium-Conjugated Curcumin Against Staphylococcus aureus.},
journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica},
volume = {133},
number = {10},
pages = {e70075},
doi = {10.1111/apm.70075},
pmid = {41090445},
issn = {1600-0463},
support = {CG-VISION PROJECT//Department of Atomic Energy, Government of India/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Curcumin/pharmacology/chemistry ; *Staphylococcus aureus/drug effects/physiology ; Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Organophosphorus Compounds/pharmacology/chemistry ; Staphylococcal Infections/microbiology/drug therapy ; Humans ; },
abstract = {Hospital- and community-acquired Staphylococcus aureus infections are dominated by their biofilms and cause difficult-to-treat persistent infections. As an alternative anti-biofilm agent, the efficacy of triphenylphosphonium (TPP)-conjugated curcumin (TPP-curcumin) was determined against S. aureus biofilms in comparison to that of curcumin and commercial antibiotics. TPP-curcumin elicited strong anti-staphylococcal activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 3.125 and 6.25 μM, respectively. The MIC and MBC values for curcumin and ampicillin were > 125 and > 286.2 μM (100 μg/mL), respectively. The MIC and MBC values were 25.7 μM (12.5 μg/mL) and 103 μM (50 μg/mL), respectively, for kanamycin. TPP-curcumin was multi-fold more effective than curcumin in inhibiting biofilm growth. Minimum biofilm inhibitory concentration (MBIC) values of TPP-curcumin, curcumin, ampicillin and kanamycin were 3.125, > 125, > 286 and 25 μM, respectively. Besides inhibiting biofilm formation, TPP-curcumin has effectively killed S. aureus cells in pre-formed or established biofilms. Treatment of biofilms with 25 μM TPP-curcumin achieved near-complete cell killing. Exposure to TPP-curcumin led to severe membrane damage and oxidative stress in S. aureus cells. The strong antimicrobial and antibiofilm activity of TPP-curcumin suggests its potential use for developing or augmenting antibacterial therapies for drug-resistant S. aureus infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Curcumin/pharmacology/chemistry
*Staphylococcus aureus/drug effects/physiology
Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology/chemistry
*Organophosphorus Compounds/pharmacology/chemistry
Staphylococcal Infections/microbiology/drug therapy
Humans
RevDate: 2025-10-15
Effectiveness of Different Diode Laser Wavelengths in Targeting Enterococcus faecalis Biofilm in Root Canal Treatment.
Reviews on recent clinical trials pii:RRCT-EPUB-150996 [Epub ahead of print].
INTRODUCTION: Disinfection of the root canal system is crucial for the effectiveness of root canal treatment. Lasers and photoactivated disinfection (PAD) have emerged as preferred methods for eliminating pathogens from the root canal.
METHOD: Sixty intact, freshly extracted adult human uniradicular mature teeth with a single root canal were collected. The crowns were removed, resulting in canals measuring 14 mm in length. The root canals were prepared, sterilized, and then inoculated with broth containing Enterococcus faecalis (E. faecalis), followed by incubation for 30 days in an aerobic environment at 37°C. Biofilm formation was verified using a scanning electron microscope. The samples were randomly divided into six experimental groups (n = 10). Group 1 consisted of teeth treated only with distilled water. Group 2 teeth received 3% NaOCl and 17% EDTA as part of Conventional Chemomechanical Debridement (CCMD) but no additional treatment. Groups 3-6 also received CCMD followed by additional laser disinfection as follows: Group 3 underwent photoactivated disinfection (PAD) using riboflavin with a 450 nm laser; Group 4 underwent PAD using toluidine blue O (TBO) with a 635 nm laser; Group 5 underwent conventional laser endodontics (CLE) with an 808 nm laser; and Group 6 underwent CLE using triple wavelengths of 450 nm, 635 nm, and 808 nm.
RESULTS: The Kruskal-Wallis test revealed significant differences in colony-forming units (CFUs) among the groups after treatment (p < 0.001). Subsequent analysis showed that the difference in mean CFUs between the PAD groups and the CLE groups was not statistically significant. The group treated with the triple laser wavelength exhibited the lowest average CFUs/mL, while the distilled water group had the highest mean value.
DISCUSSION: The study confirms that diode laser-assisted disinfection significantly enhances bacterial reduction compared with conventional irrigation alone. Although PAD methods reduced E. faecalis, their effect was not statistically superior to conventional laser endodontics (CLE). The triplewavelength diode laser group achieved the greatest bacterial reduction, likely due to the synergistic effects of thermal and photochemical interactions. These findings support the adjunctive use of laser disinfection to improve root canal decontamination, particularly when combined with chemomechanical preparation.
CONCLUSION: This study demonstrates that combining an irrigating solution with a diode laser enhances the effectiveness of reducing pathogenic numbers.
Additional Links: PMID-41088920
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PubMed:
Citation:
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@article {pmid41088920,
year = {2025},
author = {Al-Jaberi, M and Atshan, SS and Zouiten, S},
title = {Effectiveness of Different Diode Laser Wavelengths in Targeting Enterococcus faecalis Biofilm in Root Canal Treatment.},
journal = {Reviews on recent clinical trials},
volume = {},
number = {},
pages = {},
doi = {10.2174/0115748871367667250912111157},
pmid = {41088920},
issn = {1876-1038},
abstract = {INTRODUCTION: Disinfection of the root canal system is crucial for the effectiveness of root canal treatment. Lasers and photoactivated disinfection (PAD) have emerged as preferred methods for eliminating pathogens from the root canal.
METHOD: Sixty intact, freshly extracted adult human uniradicular mature teeth with a single root canal were collected. The crowns were removed, resulting in canals measuring 14 mm in length. The root canals were prepared, sterilized, and then inoculated with broth containing Enterococcus faecalis (E. faecalis), followed by incubation for 30 days in an aerobic environment at 37°C. Biofilm formation was verified using a scanning electron microscope. The samples were randomly divided into six experimental groups (n = 10). Group 1 consisted of teeth treated only with distilled water. Group 2 teeth received 3% NaOCl and 17% EDTA as part of Conventional Chemomechanical Debridement (CCMD) but no additional treatment. Groups 3-6 also received CCMD followed by additional laser disinfection as follows: Group 3 underwent photoactivated disinfection (PAD) using riboflavin with a 450 nm laser; Group 4 underwent PAD using toluidine blue O (TBO) with a 635 nm laser; Group 5 underwent conventional laser endodontics (CLE) with an 808 nm laser; and Group 6 underwent CLE using triple wavelengths of 450 nm, 635 nm, and 808 nm.
RESULTS: The Kruskal-Wallis test revealed significant differences in colony-forming units (CFUs) among the groups after treatment (p < 0.001). Subsequent analysis showed that the difference in mean CFUs between the PAD groups and the CLE groups was not statistically significant. The group treated with the triple laser wavelength exhibited the lowest average CFUs/mL, while the distilled water group had the highest mean value.
DISCUSSION: The study confirms that diode laser-assisted disinfection significantly enhances bacterial reduction compared with conventional irrigation alone. Although PAD methods reduced E. faecalis, their effect was not statistically superior to conventional laser endodontics (CLE). The triplewavelength diode laser group achieved the greatest bacterial reduction, likely due to the synergistic effects of thermal and photochemical interactions. These findings support the adjunctive use of laser disinfection to improve root canal decontamination, particularly when combined with chemomechanical preparation.
CONCLUSION: This study demonstrates that combining an irrigating solution with a diode laser enhances the effectiveness of reducing pathogenic numbers.},
}
RevDate: 2025-10-14
Role of biofilm carriers in sulfamethoxazole removal and microbial adaptation strategies in integrated fixed-film activated sludge system.
Bioresource technology pii:S0960-8524(25)01448-8 [Epub ahead of print].
Attached-growth biofilm processes using specific biofilm carriers are widely employed to enhance antibiotic removal. However, the relationship between antibiotic degradation, resistance risks and microbial adaptation strategies across different carriers is not yet fully understood. Hence, four common biofilm systems, including iron-carbon (Fe@C), granular activated carbon (GAC), ceramic (CE), and polyurethane (PU), were evaluated for sulfamethoxazole (SMX) removal and antibiotic resistance genes (ARGs) risks. GAC and Fe@C systems exhibited higher SMX removal performance, achieving removal efficiency > 99.0 % and 63.8 %, respectively, compared to other carriers (17.4-49.8 %). Moreover, GAC reduced ARGs by 34.8-47.7 % via inhibiting horizontal gene transfer, as demonstrated by a 50.6-74.5 % decrease in core MGEs (intI1_337old, IS6100, and tnpA-2). Conversely, Fe@C exacerbated ARGs accumulation. The high specific surface area and rich pore structure of GAC promoted the colonization of potential SMX-degrading bacteria, notably Thauera, and shaped a multifunctional biofilm system. GAC biofilms exhibited distinct advantages in signal transduction and biofilm formation pathways. Meanwhile, the adsorption capacity of the GAC carrier created a hotspot for SMX biodegradation. This study provides a comprehensive understanding of antibiotic removal and spread of ARGs through the biofilm process.
Additional Links: PMID-41086969
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PubMed:
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@article {pmid41086969,
year = {2025},
author = {Min, B and Xie, J and He, Y and Lin, R and Azari, M and Xie, L},
title = {Role of biofilm carriers in sulfamethoxazole removal and microbial adaptation strategies in integrated fixed-film activated sludge system.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {133481},
doi = {10.1016/j.biortech.2025.133481},
pmid = {41086969},
issn = {1873-2976},
abstract = {Attached-growth biofilm processes using specific biofilm carriers are widely employed to enhance antibiotic removal. However, the relationship between antibiotic degradation, resistance risks and microbial adaptation strategies across different carriers is not yet fully understood. Hence, four common biofilm systems, including iron-carbon (Fe@C), granular activated carbon (GAC), ceramic (CE), and polyurethane (PU), were evaluated for sulfamethoxazole (SMX) removal and antibiotic resistance genes (ARGs) risks. GAC and Fe@C systems exhibited higher SMX removal performance, achieving removal efficiency > 99.0 % and 63.8 %, respectively, compared to other carriers (17.4-49.8 %). Moreover, GAC reduced ARGs by 34.8-47.7 % via inhibiting horizontal gene transfer, as demonstrated by a 50.6-74.5 % decrease in core MGEs (intI1_337old, IS6100, and tnpA-2). Conversely, Fe@C exacerbated ARGs accumulation. The high specific surface area and rich pore structure of GAC promoted the colonization of potential SMX-degrading bacteria, notably Thauera, and shaped a multifunctional biofilm system. GAC biofilms exhibited distinct advantages in signal transduction and biofilm formation pathways. Meanwhile, the adsorption capacity of the GAC carrier created a hotspot for SMX biodegradation. This study provides a comprehensive understanding of antibiotic removal and spread of ARGs through the biofilm process.},
}
RevDate: 2025-10-14
Elucidating the role of extracellular polymeric substances (EPS) in modulating autotrophic-heterotrophic interactions in a pyrite-assisted autotrophic denitrification biofilm.
Bioresource technology pii:S0960-8524(25)01454-3 [Epub ahead of print].
Autotrophic biofilm systems have been applied for nitrate removal from organic matter-poor waters. Nevertheless, heterotrophs can survive long-term fully autotrophic conditions, with stable or even increasing populations. Extracellular polymeric substances (EPS) are reported to sustain heterotrophic growth in such systems, but their role in regulating biofilm structure, population networks, and gene abundance remains unclear. In this study, we investigated microbial, functional gene, and EPS dynamics in a pyrite-assisted autotrophic denitrification (PAD) biofilter operated for 180 days. Despite fully autotrophic operating conditions, sulfur-oxidizing denitrifiers and their genes decreased over time, while EPS sustained heterotrophic anaerobes throughout the experimental periods. Biofilm maturation led to EPS conversion into filaments with potential conductive properties that facilitated electron transfer between microbes, pyrite, and nitrate. Polysaccharides in EPS were preferentially consumed over proteins, increasing the protein/polysaccharide ratio. Based on these results, a three-phase biofilm development model (initial attachment, maturation, and disassembly/restructuring) was proposed, linking temporal changes in EPS composition and microbial community structure to biofilm architecture and sustained denitrification.
Additional Links: PMID-41086965
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PubMed:
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@article {pmid41086965,
year = {2025},
author = {Zhu, Y and Wu, H and Cui, S and Capua, FD and Shi, Z and Li, H},
title = {Elucidating the role of extracellular polymeric substances (EPS) in modulating autotrophic-heterotrophic interactions in a pyrite-assisted autotrophic denitrification biofilm.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {133487},
doi = {10.1016/j.biortech.2025.133487},
pmid = {41086965},
issn = {1873-2976},
abstract = {Autotrophic biofilm systems have been applied for nitrate removal from organic matter-poor waters. Nevertheless, heterotrophs can survive long-term fully autotrophic conditions, with stable or even increasing populations. Extracellular polymeric substances (EPS) are reported to sustain heterotrophic growth in such systems, but their role in regulating biofilm structure, population networks, and gene abundance remains unclear. In this study, we investigated microbial, functional gene, and EPS dynamics in a pyrite-assisted autotrophic denitrification (PAD) biofilter operated for 180 days. Despite fully autotrophic operating conditions, sulfur-oxidizing denitrifiers and their genes decreased over time, while EPS sustained heterotrophic anaerobes throughout the experimental periods. Biofilm maturation led to EPS conversion into filaments with potential conductive properties that facilitated electron transfer between microbes, pyrite, and nitrate. Polysaccharides in EPS were preferentially consumed over proteins, increasing the protein/polysaccharide ratio. Based on these results, a three-phase biofilm development model (initial attachment, maturation, and disassembly/restructuring) was proposed, linking temporal changes in EPS composition and microbial community structure to biofilm architecture and sustained denitrification.},
}
RevDate: 2025-10-14
Role of gene PA2798 on biofilm formation and virulence factors production of Pseudomonas aeruginosa.
Folia microbiologica [Epub ahead of print].
Bacterial biofilm formation plays a critical role in the pathogenicity and virulence of Pseudomonas aeruginosa posing a significant threat to human health. Previously, the uncharacterized P. aeruginosa gene PA2798, was identified as a contributor to its resistance to antibiofilm peptide. However, the functional role of PA2798 and the underlying mechanisms by which it regulates biofilm formation and virulence factor production remain largely unexplored. In this study, a PA2798-deficient mutant (PAO1∆PA2798) was constructed, and aminoglycosides minimum inhibitory concentrations (MICs) were measured to assess the effect of PA2798 on antibiotic susceptibility. In addition, both in vitro phenotypic assays and in vivo experiments in chronic and acute lung infection mice models were performed to evaluate the role of PA2798 in bacterial biofilm associated infection and its potential as an antimicrobial target. Results demonstrated that deletion of PA2798 led to fourfold decreases in MICs for gentamicin, amikacin, tobramycin and netilmicin, and was accompanied by reduced biofilm biomass and virulence factor production in PAO1∆PA2798. Moreover, compromised cellular integrity, reduced bacterial activity, and impaired bacterial motility were observed in PAO1∆PA2798. Simultaneously, mice infected with this mutant strain were observed with the reduction of bacterial colonization and improved survival in both chronic and acute in vivo models. Conclusively, our findings support a role for PA2798 in aminoglycoside resistance, biofilm formation and virulence factor production in P. aeruginosa, highlighting its potential as a target for therapeutic intervention in biofilm-associated infections.
Additional Links: PMID-41085950
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@article {pmid41085950,
year = {2025},
author = {Li, HL and Chen, L and Ma, ZW and Yan, J and Lu, XL and Nie, H and Yin, Q and Li, YL},
title = {Role of gene PA2798 on biofilm formation and virulence factors production of Pseudomonas aeruginosa.},
journal = {Folia microbiologica},
volume = {},
number = {},
pages = {},
pmid = {41085950},
issn = {1874-9356},
support = {No.32100139//National Natural Science Foundation of China/ ; No.sl202100000725//Chongqing Municipal Science and Technology Bureau/ ; },
abstract = {Bacterial biofilm formation plays a critical role in the pathogenicity and virulence of Pseudomonas aeruginosa posing a significant threat to human health. Previously, the uncharacterized P. aeruginosa gene PA2798, was identified as a contributor to its resistance to antibiofilm peptide. However, the functional role of PA2798 and the underlying mechanisms by which it regulates biofilm formation and virulence factor production remain largely unexplored. In this study, a PA2798-deficient mutant (PAO1∆PA2798) was constructed, and aminoglycosides minimum inhibitory concentrations (MICs) were measured to assess the effect of PA2798 on antibiotic susceptibility. In addition, both in vitro phenotypic assays and in vivo experiments in chronic and acute lung infection mice models were performed to evaluate the role of PA2798 in bacterial biofilm associated infection and its potential as an antimicrobial target. Results demonstrated that deletion of PA2798 led to fourfold decreases in MICs for gentamicin, amikacin, tobramycin and netilmicin, and was accompanied by reduced biofilm biomass and virulence factor production in PAO1∆PA2798. Moreover, compromised cellular integrity, reduced bacterial activity, and impaired bacterial motility were observed in PAO1∆PA2798. Simultaneously, mice infected with this mutant strain were observed with the reduction of bacterial colonization and improved survival in both chronic and acute in vivo models. Conclusively, our findings support a role for PA2798 in aminoglycoside resistance, biofilm formation and virulence factor production in P. aeruginosa, highlighting its potential as a target for therapeutic intervention in biofilm-associated infections.},
}
RevDate: 2025-10-14
CmpDate: 2025-10-14
Effects of copper stress on biofilm and capsule gene expression of Streptococcus agalactiae isolated from bovine mastitis.
Archives of microbiology, 207(11):309.
Streptococcus agalactiae biofilms challenge dairy farms by harming animal health and milk quality. Copper shows antimicrobial activity against mastitis pathogens, but its effect on S. agalactiae is unclear. This study aimed to evaluate the impact of copper on S. agalactiae isolates from cows with mastitis, evaluating its effects across multiple aspects of bacterial behavior and transcriptional responses. The 29 isolates were characterized, revealing predominantly capsular type Ia (62%) and III (38%). All isolates formed biofilms, classified as strong (59%), moderate (34%), or weak (7%) producers. The minimal inhibitory concentration (MIC) of copper was determined to be 4 mM for all isolates. Copper reduced planktonic growth, primarily affecting the maximal growth potential, while generation time and growth rate remained largely unchanged. Biofilm formation was significantly reduced in two of three selected isolates, while one isolate remained unaffected. Copper surfaces (99.9%) exhibited a bactericidal effect, producing a 3-log reduction in bacterial load within 50 min, independent of biofilm-forming capacity. Copper exposure induced expression of copY and copA genes in all three isolates, and capIa expression increased in one isolate. These findings provide novel evidence that copper can inhibit S. agalactiae growth and biofilm formation, highlighting its potential as an alternative strategy for controlling this pathogen in dairy farms.
Additional Links: PMID-41085672
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@article {pmid41085672,
year = {2025},
author = {Bonsaglia, ECR and Quesille-Villalobos, AM and Rall, VLM and Pantoja, JCF and Silva, NCC and Santos, MV and Reyes-Jara, A},
title = {Effects of copper stress on biofilm and capsule gene expression of Streptococcus agalactiae isolated from bovine mastitis.},
journal = {Archives of microbiology},
volume = {207},
number = {11},
pages = {309},
pmid = {41085672},
issn = {1432-072X},
support = {22/13775-0//Fundação de Amparo a Pesquisa do Estado de Sao Paulo/ ; 1241084//Fondecyt/ ; },
mesh = {*Biofilms/drug effects/growth & development ; Animals ; *Streptococcus agalactiae/drug effects/genetics/isolation & purification/physiology ; Cattle ; *Copper/pharmacology ; *Mastitis, Bovine/microbiology ; Female ; *Streptococcal Infections/veterinary/microbiology ; Microbial Sensitivity Tests ; *Bacterial Capsules/genetics/drug effects/metabolism ; Gene Expression Regulation, Bacterial/drug effects ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics/metabolism ; },
abstract = {Streptococcus agalactiae biofilms challenge dairy farms by harming animal health and milk quality. Copper shows antimicrobial activity against mastitis pathogens, but its effect on S. agalactiae is unclear. This study aimed to evaluate the impact of copper on S. agalactiae isolates from cows with mastitis, evaluating its effects across multiple aspects of bacterial behavior and transcriptional responses. The 29 isolates were characterized, revealing predominantly capsular type Ia (62%) and III (38%). All isolates formed biofilms, classified as strong (59%), moderate (34%), or weak (7%) producers. The minimal inhibitory concentration (MIC) of copper was determined to be 4 mM for all isolates. Copper reduced planktonic growth, primarily affecting the maximal growth potential, while generation time and growth rate remained largely unchanged. Biofilm formation was significantly reduced in two of three selected isolates, while one isolate remained unaffected. Copper surfaces (99.9%) exhibited a bactericidal effect, producing a 3-log reduction in bacterial load within 50 min, independent of biofilm-forming capacity. Copper exposure induced expression of copY and copA genes in all three isolates, and capIa expression increased in one isolate. These findings provide novel evidence that copper can inhibit S. agalactiae growth and biofilm formation, highlighting its potential as an alternative strategy for controlling this pathogen in dairy farms.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
Animals
*Streptococcus agalactiae/drug effects/genetics/isolation & purification/physiology
Cattle
*Copper/pharmacology
*Mastitis, Bovine/microbiology
Female
*Streptococcal Infections/veterinary/microbiology
Microbial Sensitivity Tests
*Bacterial Capsules/genetics/drug effects/metabolism
Gene Expression Regulation, Bacterial/drug effects
Anti-Bacterial Agents/pharmacology
Bacterial Proteins/genetics/metabolism
RevDate: 2025-10-13
CmpDate: 2025-10-13
Correlation between Biofilm Development and Antibiotic Resistance in Staphylococcus haemolyticus.
Medicinski glasnik : official publication of the Medical Association of Zenica-Doboj Canton, Bosnia and Herzegovina, 22(2):195-200.
AIM: This study aimed to evaluate antibiotic resistance, biofilm formation, and the presence of virulence-associated genes in Staphylococcus haemolyticus isolates.
METHODS: Clinical specimens were obtained from patients in Mosul city. Antibiotic susceptibility was determined using the Kirby–Bauer disk diffusion method against fourteen antibiotics Biofilm production was assessed by both the tube adherence method and the microtiter plate assay. Polymerase chain reaction (PCR) was employed to detect selected resistance and virulence genes.
RESULTS: The isolates exhibited high resistance rates to ampicillin (94.7%) and cloxacillin (94.7%). These antibiotics were tested separately to compare β-lactamase-labile (ampicillin) and β-lactamase-stable (cloxacillin) penicillins. All isolates were uniformly susceptible to vancomycin. Nitrofurantoin was not included in the final interpretation due to its limited clinical relevance in non-urinary tract infections, especially considering that S. haemolyticus is not a typical uropathogen. Variable resistance patterns were observed with other antibiotics. All isolates demonstrated biofilm production. PCR analysis revealed the presence of the SH gene in 100% of isolates. The mecA gene, conferring methicillin resistance, was detected in 88.88% of isolates; tetK (tetracycline resistance) in 83.33%; and ermC (erythromycin resistance) in 26.31%. Among the virulence factors, hla and fnbB were found in 100% and 73.68% of isolates, respectively.
CONCLUSION: The study highlights the alarming antibiotic resistance, strong biofilm-forming ability, and high prevalence of virulence and resistance genes in S. haemolyticus, reinforcing concerns over the global spread of multidrug-resistant organisms.
Additional Links: PMID-41082738
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@article {pmid41082738,
year = {2025},
author = {Mohammedali, Y and Abed, S},
title = {Correlation between Biofilm Development and Antibiotic Resistance in Staphylococcus haemolyticus.},
journal = {Medicinski glasnik : official publication of the Medical Association of Zenica-Doboj Canton, Bosnia and Herzegovina},
volume = {22},
number = {2},
pages = {195-200},
doi = {10.17392/1976-22-02},
pmid = {41082738},
issn = {1840-2445},
mesh = {*Biofilms/growth & development/drug effects ; Humans ; *Staphylococcus haemolyticus/drug effects/genetics/physiology/pathogenicity/isolation & purification ; *Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; *Drug Resistance, Bacterial/genetics ; *Staphylococcal Infections/microbiology/drug therapy ; Polymerase Chain Reaction ; Virulence/genetics ; Drug Resistance, Multiple, Bacterial ; },
abstract = {AIM: This study aimed to evaluate antibiotic resistance, biofilm formation, and the presence of virulence-associated genes in Staphylococcus haemolyticus isolates.
METHODS: Clinical specimens were obtained from patients in Mosul city. Antibiotic susceptibility was determined using the Kirby–Bauer disk diffusion method against fourteen antibiotics Biofilm production was assessed by both the tube adherence method and the microtiter plate assay. Polymerase chain reaction (PCR) was employed to detect selected resistance and virulence genes.
RESULTS: The isolates exhibited high resistance rates to ampicillin (94.7%) and cloxacillin (94.7%). These antibiotics were tested separately to compare β-lactamase-labile (ampicillin) and β-lactamase-stable (cloxacillin) penicillins. All isolates were uniformly susceptible to vancomycin. Nitrofurantoin was not included in the final interpretation due to its limited clinical relevance in non-urinary tract infections, especially considering that S. haemolyticus is not a typical uropathogen. Variable resistance patterns were observed with other antibiotics. All isolates demonstrated biofilm production. PCR analysis revealed the presence of the SH gene in 100% of isolates. The mecA gene, conferring methicillin resistance, was detected in 88.88% of isolates; tetK (tetracycline resistance) in 83.33%; and ermC (erythromycin resistance) in 26.31%. Among the virulence factors, hla and fnbB were found in 100% and 73.68% of isolates, respectively.
CONCLUSION: The study highlights the alarming antibiotic resistance, strong biofilm-forming ability, and high prevalence of virulence and resistance genes in S. haemolyticus, reinforcing concerns over the global spread of multidrug-resistant organisms.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development/drug effects
Humans
*Staphylococcus haemolyticus/drug effects/genetics/physiology/pathogenicity/isolation & purification
*Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests
*Drug Resistance, Bacterial/genetics
*Staphylococcal Infections/microbiology/drug therapy
Polymerase Chain Reaction
Virulence/genetics
Drug Resistance, Multiple, Bacterial
RevDate: 2025-10-13
CmpDate: 2025-10-13
Freezing stress and meat juice model alter the biofilm formation ability, gene expression, and disinfectant resistance in Salmonella serotypes.
One health (Amsterdam, Netherlands), 21:101220.
Salmonella, with its ability to survive under various environmental stress conditions, can pose a potential threat to public health, food safety, and environmental contamination by increasing its capacity to form biofilms and resist antimicrobial agents. This study aimed to investigate the effects of different meat juice models (cattle, sheep and goat meat juice) and freezing time (0-30 days) on the biofilm formation ability, AdrA and BapA genes expression, and disinfectant resistance in Salmonella serotypes. Biofilm formation ability was measured by colony counting method, the gene expression level was evaluated using real-time quantitative polymerase chain reaction (qPCR), and resistance to acetic acid (AA) and benzalkonium chloride (BAC) was measured by determining the minimum inhibitory concentration (MIC). The most significant increase in biofilm formation ability was observed in Salmonella Typhimurium (S. Typhimurium) in goat meat juice model. Salmonella Enteritidis (S. Enteritidis) in the cattle meat juice model exhibited a 12-fold increase in AdrA gene expression. Up-regulation of AdrA expression (up to 11-fold) was also determined in S. Typhimurium in goat meat juice model. Meanwhile, BapA gene was up-regulated up to 4.5-fold in S. Typhimurium in cattle meat juice. However, goat meat juice had no significant effect on the expression of BapA gene in Salmonella. The frozen sheep meat juice significantly increased the resistance of Salmonella to AA and BAC. The results indicated that Salmonella serotypes respond significantly to the freezing period and type of meat juice, which can be useful in controlling and eliminating Salmonella in the food industry.
Additional Links: PMID-41079163
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@article {pmid41079163,
year = {2025},
author = {Kaboudari, A and Aliakbarlu, J},
title = {Freezing stress and meat juice model alter the biofilm formation ability, gene expression, and disinfectant resistance in Salmonella serotypes.},
journal = {One health (Amsterdam, Netherlands)},
volume = {21},
number = {},
pages = {101220},
pmid = {41079163},
issn = {2352-7714},
abstract = {Salmonella, with its ability to survive under various environmental stress conditions, can pose a potential threat to public health, food safety, and environmental contamination by increasing its capacity to form biofilms and resist antimicrobial agents. This study aimed to investigate the effects of different meat juice models (cattle, sheep and goat meat juice) and freezing time (0-30 days) on the biofilm formation ability, AdrA and BapA genes expression, and disinfectant resistance in Salmonella serotypes. Biofilm formation ability was measured by colony counting method, the gene expression level was evaluated using real-time quantitative polymerase chain reaction (qPCR), and resistance to acetic acid (AA) and benzalkonium chloride (BAC) was measured by determining the minimum inhibitory concentration (MIC). The most significant increase in biofilm formation ability was observed in Salmonella Typhimurium (S. Typhimurium) in goat meat juice model. Salmonella Enteritidis (S. Enteritidis) in the cattle meat juice model exhibited a 12-fold increase in AdrA gene expression. Up-regulation of AdrA expression (up to 11-fold) was also determined in S. Typhimurium in goat meat juice model. Meanwhile, BapA gene was up-regulated up to 4.5-fold in S. Typhimurium in cattle meat juice. However, goat meat juice had no significant effect on the expression of BapA gene in Salmonella. The frozen sheep meat juice significantly increased the resistance of Salmonella to AA and BAC. The results indicated that Salmonella serotypes respond significantly to the freezing period and type of meat juice, which can be useful in controlling and eliminating Salmonella in the food industry.},
}
RevDate: 2025-10-13
CmpDate: 2025-10-13
Bacteria microenvironment-responsive missile microneedles modulate immunity and penetrate biofilm for diabetic wound therapy.
Bioactive materials, 55:426-445.
Diabetic wounds, affecting ∼25 % of patients with diabetes, present a therapeutic challenge due to persistent inflammation driven by MCP-1-mediated immune dysregulation and bacterial biofilm formation. We developed a bilayer microneedle system (DAg/HTMS-MNs) combining dextran-modified silver nanoparticles for deep-tissue antibacterial action with heparin-coated taurine-loaded microspheres for immunomodulation. The upper microneedle segment enables biofilm penetration through lectin targeting and gas propulsion, while the lower segment implements a "global decompression-local enhancement" strategy: heparin sequesters MCP-1 to reduce inflammatory cell recruitment, and sustained taurine release promotes macrophage reprogramming to M2 phenotypes. Systematic evaluation demonstrated simultaneous biofilm eradication, inflammation resolution (2-fold enhanced M2 polarization), and accelerated wound healing. This "missile-guided" approach represents a paradigm shift in diabetic wound therapy by concurrently addressing infection control, oxidative stress, and immune dysregulation in a spatially and temporally controlled manner.
Additional Links: PMID-41078863
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@article {pmid41078863,
year = {2026},
author = {Yang, G and Kang, H and Zhu, Y and Wu, H and Zhang, M and Zeng, X and Peng, Y and Wan, W and Yi, Y},
title = {Bacteria microenvironment-responsive missile microneedles modulate immunity and penetrate biofilm for diabetic wound therapy.},
journal = {Bioactive materials},
volume = {55},
number = {},
pages = {426-445},
pmid = {41078863},
issn = {2452-199X},
abstract = {Diabetic wounds, affecting ∼25 % of patients with diabetes, present a therapeutic challenge due to persistent inflammation driven by MCP-1-mediated immune dysregulation and bacterial biofilm formation. We developed a bilayer microneedle system (DAg/HTMS-MNs) combining dextran-modified silver nanoparticles for deep-tissue antibacterial action with heparin-coated taurine-loaded microspheres for immunomodulation. The upper microneedle segment enables biofilm penetration through lectin targeting and gas propulsion, while the lower segment implements a "global decompression-local enhancement" strategy: heparin sequesters MCP-1 to reduce inflammatory cell recruitment, and sustained taurine release promotes macrophage reprogramming to M2 phenotypes. Systematic evaluation demonstrated simultaneous biofilm eradication, inflammation resolution (2-fold enhanced M2 polarization), and accelerated wound healing. This "missile-guided" approach represents a paradigm shift in diabetic wound therapy by concurrently addressing infection control, oxidative stress, and immune dysregulation in a spatially and temporally controlled manner.},
}
RevDate: 2025-10-13
CmpDate: 2025-10-13
Study on the impact of biofilm formation by Candida albicans in recurrent vulvovaginal candidiasis on drug susceptibility.
Frontiers in cellular and infection microbiology, 15:1663099.
BACKGROUND: Vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC) are common fungal infections in women, often complicated by recurrence and treatment resistance. This study explores how Candida albicans biofilm formation influences antifungal susceptibility and resistance gene expression in clinical isolates.
METHODS: Clinical Candida albicans isolates were collected and identified. Biofilm formation ability was assessed using crystal violet staining and confocal laser scanning microscopy. Based on the strength of biofilm formation, isolates from VVC and RVVC patients were categorized into three groups: strong positive, moderate positive, and weak positive. The antifungal susceptibility of each strain to fluconazole, flucytosine, clotrimazole, and amphotericin B was determined using a modified broth microdilution method. The expression levels of the drug efflux pump genes CDR1, CDR2, and MDR1 were measured before and after biofilm formation in each group using RT-qPCR.
RESULTS: A higher proportion of strong biofilm-forming Candida albicans strains was of Candida albicans served in the RVVC group, whereas biofilm-negative strains were less common. In the VVC group, weak biofilm-formers produced significantly thinner biofilms than strong biofilm-formers in both VVC and RVVC (p<0.05). In RVVC weak biofilm-formers, amphotericin B exhibited higher MIC values than fluconazole and flucytosine (p<0.05), and across all RVVC subgroups, amphotericin B MICs were higher than those of clotrimazole (p<0.05). The MBEC of flucytosine was highest in the strongly positive VVC subgroup (p<0.05). In VVC, clotrimazole MBEC was lower in weak than in strong biofilm-formers (p<0.05). In RVVC, fluconazole MBEC was higher than flucytosine and clotrimazole in weak biofilm-formers, and also higher than amphotericin B in both weak and moderate biofilm-formers (p<0.05). Multivariate analysis further suggested that stronger biofilm-forming ability tended to increase the risk of RVVC independently of age, although this association did not reach statistical significance.
CONCLUSIONS: Stronger biofilm-forming Candida albicans strains showed higher MBEC values. In RVVC, clotrimazole had the lowest MIC and MBEC, supporting its potential as a first-line treatment. Expression of CDR1 and CDR2 was highest in strong biofilm-forming strains, suggesting that biofilm formation promotes antifungal resistance through enhanced efflux gene expression, especially in RVVC.
Additional Links: PMID-41078368
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@article {pmid41078368,
year = {2025},
author = {Li, S and Shen, Z and Wang, S and Peng, Y and Qi, W},
title = {Study on the impact of biofilm formation by Candida albicans in recurrent vulvovaginal candidiasis on drug susceptibility.},
journal = {Frontiers in cellular and infection microbiology},
volume = {15},
number = {},
pages = {1663099},
pmid = {41078368},
issn = {2235-2988},
mesh = {*Biofilms/growth & development/drug effects ; *Candidiasis, Vulvovaginal/microbiology/drug therapy ; *Candida albicans/drug effects/physiology/genetics/isolation & purification ; *Antifungal Agents/pharmacology ; Humans ; Female ; Microbial Sensitivity Tests ; Drug Resistance, Fungal/genetics ; Fluconazole/pharmacology ; Clotrimazole/pharmacology ; Fungal Proteins/genetics ; Amphotericin B/pharmacology ; Flucytosine/pharmacology ; Recurrence ; Membrane Transport Proteins/genetics ; },
abstract = {BACKGROUND: Vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC) are common fungal infections in women, often complicated by recurrence and treatment resistance. This study explores how Candida albicans biofilm formation influences antifungal susceptibility and resistance gene expression in clinical isolates.
METHODS: Clinical Candida albicans isolates were collected and identified. Biofilm formation ability was assessed using crystal violet staining and confocal laser scanning microscopy. Based on the strength of biofilm formation, isolates from VVC and RVVC patients were categorized into three groups: strong positive, moderate positive, and weak positive. The antifungal susceptibility of each strain to fluconazole, flucytosine, clotrimazole, and amphotericin B was determined using a modified broth microdilution method. The expression levels of the drug efflux pump genes CDR1, CDR2, and MDR1 were measured before and after biofilm formation in each group using RT-qPCR.
RESULTS: A higher proportion of strong biofilm-forming Candida albicans strains was of Candida albicans served in the RVVC group, whereas biofilm-negative strains were less common. In the VVC group, weak biofilm-formers produced significantly thinner biofilms than strong biofilm-formers in both VVC and RVVC (p<0.05). In RVVC weak biofilm-formers, amphotericin B exhibited higher MIC values than fluconazole and flucytosine (p<0.05), and across all RVVC subgroups, amphotericin B MICs were higher than those of clotrimazole (p<0.05). The MBEC of flucytosine was highest in the strongly positive VVC subgroup (p<0.05). In VVC, clotrimazole MBEC was lower in weak than in strong biofilm-formers (p<0.05). In RVVC, fluconazole MBEC was higher than flucytosine and clotrimazole in weak biofilm-formers, and also higher than amphotericin B in both weak and moderate biofilm-formers (p<0.05). Multivariate analysis further suggested that stronger biofilm-forming ability tended to increase the risk of RVVC independently of age, although this association did not reach statistical significance.
CONCLUSIONS: Stronger biofilm-forming Candida albicans strains showed higher MBEC values. In RVVC, clotrimazole had the lowest MIC and MBEC, supporting its potential as a first-line treatment. Expression of CDR1 and CDR2 was highest in strong biofilm-forming strains, suggesting that biofilm formation promotes antifungal resistance through enhanced efflux gene expression, especially in RVVC.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development/drug effects
*Candidiasis, Vulvovaginal/microbiology/drug therapy
*Candida albicans/drug effects/physiology/genetics/isolation & purification
*Antifungal Agents/pharmacology
Humans
Female
Microbial Sensitivity Tests
Drug Resistance, Fungal/genetics
Fluconazole/pharmacology
Clotrimazole/pharmacology
Fungal Proteins/genetics
Amphotericin B/pharmacology
Flucytosine/pharmacology
Recurrence
Membrane Transport Proteins/genetics
RevDate: 2025-10-13
Potential application of vitamins to combat biofilm-mediated drug resistance by pathogenic bacteria.
Future microbiology [Epub ahead of print].
Biofilm is one of the causes of pathogenic bacteria's resistance to drugs. Vitamins, essential for maintaining various physiological functions within the animal body, have been observed to influence biofilm inhibition. The vitamins A, C, D, E, K, B6, and B12 possess notable anti-biofilm activity against specific pathogens, which have been reported extensively over the last few years, highlighting their potential in combating microbial infections. Vitamins B and K possess anti-quorum-sensing effects, which also contribute to the reduction of virulence factor expression of pathogenic bacteria. Many research reports have identified the incremental effectiveness of antibiotics when combined with various vitamins against bacterial infections, demonstrating a synergistic relationship between vitamins and conventional antibiotics that enhances the efficacy of antibiotics against the biofilm-mediated drug resistance capacity of microbes. According to current research, many vitamins, including vitamin A, D, and K, are responsible for binding to key proteins involved in biofilm production. However, the mechanisms of action of vitamins in combination with antibiotics against microbes require further elucidation to compensate for the existing information gap. This comprehensive review highlights, for the first time, that the least toxic biological molecules, "vitamins," can potentially manage biofilm-related microbial infections and enhance the therapeutic options available to clinicians.
Additional Links: PMID-41077817
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@article {pmid41077817,
year = {2025},
author = {Konatam, S and Panigrahi, S and Tandi, A and Roy, DN},
title = {Potential application of vitamins to combat biofilm-mediated drug resistance by pathogenic bacteria.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {1-17},
doi = {10.1080/17460913.2025.2572934},
pmid = {41077817},
issn = {1746-0921},
abstract = {Biofilm is one of the causes of pathogenic bacteria's resistance to drugs. Vitamins, essential for maintaining various physiological functions within the animal body, have been observed to influence biofilm inhibition. The vitamins A, C, D, E, K, B6, and B12 possess notable anti-biofilm activity against specific pathogens, which have been reported extensively over the last few years, highlighting their potential in combating microbial infections. Vitamins B and K possess anti-quorum-sensing effects, which also contribute to the reduction of virulence factor expression of pathogenic bacteria. Many research reports have identified the incremental effectiveness of antibiotics when combined with various vitamins against bacterial infections, demonstrating a synergistic relationship between vitamins and conventional antibiotics that enhances the efficacy of antibiotics against the biofilm-mediated drug resistance capacity of microbes. According to current research, many vitamins, including vitamin A, D, and K, are responsible for binding to key proteins involved in biofilm production. However, the mechanisms of action of vitamins in combination with antibiotics against microbes require further elucidation to compensate for the existing information gap. This comprehensive review highlights, for the first time, that the least toxic biological molecules, "vitamins," can potentially manage biofilm-related microbial infections and enhance the therapeutic options available to clinicians.},
}
RevDate: 2025-10-12
Anti-biofilm efficiency and substrate specificity of recombinantly produced human paraoxonases.
Enzyme and microbial technology, 192:110760 pii:S0141-0229(25)00180-2 [Epub ahead of print].
The human paraoxonase (PON) gene family, comprising PON1, PON2, and PON3, has evolved through parallel evolutionary trajectories leading to distinct substrate selectivity, thereby enabling these enzymes to hydrolyze a range of substrates such as lactones, arylesters, and organophosphates. This study explores the evolutionary divergence of PON family members and their varied anti-biofilm activities through in silico molecular docking and in vitro analysis. The huPON1, huPON2, and huPON3 genes were cloned and expressed in the E. coli expression system. These overexpressed proteins formed inclusion bodies, which were further subjected to in vitro refolding and biochemical characterization. The enzymatic studies revealed that huPON1 has unique paraoxonase activity and high arylesterase activity, while huPON2 demonstrated the highest lactonase activity, followed by huPON3 and huPON1. A comparative assessment of the anti-biofilm potential of recombinant huPONs was conducted against Mycobacterium smegmatis, which revealed that all three paraoxonases inhibited biofilm formation; however, huPON2 displayed the highest anti-biofilm activity, followed by huPON3 and huPON1. Additionally, all the huPONs showed a synergistic effect with the conventional TB drug, Rifampicin, in enhancing biofilm disruption. These findings contribute valuable insights into the application of huPONs as a therapeutic tool against drug-resistant bacterial infections.
Additional Links: PMID-41076986
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@article {pmid41076986,
year = {2025},
author = {Goel, M and Yadav, P and Parween, F and Mukherjee, S and Gupta, RD},
title = {Anti-biofilm efficiency and substrate specificity of recombinantly produced human paraoxonases.},
journal = {Enzyme and microbial technology},
volume = {192},
number = {},
pages = {110760},
doi = {10.1016/j.enzmictec.2025.110760},
pmid = {41076986},
issn = {1879-0909},
abstract = {The human paraoxonase (PON) gene family, comprising PON1, PON2, and PON3, has evolved through parallel evolutionary trajectories leading to distinct substrate selectivity, thereby enabling these enzymes to hydrolyze a range of substrates such as lactones, arylesters, and organophosphates. This study explores the evolutionary divergence of PON family members and their varied anti-biofilm activities through in silico molecular docking and in vitro analysis. The huPON1, huPON2, and huPON3 genes were cloned and expressed in the E. coli expression system. These overexpressed proteins formed inclusion bodies, which were further subjected to in vitro refolding and biochemical characterization. The enzymatic studies revealed that huPON1 has unique paraoxonase activity and high arylesterase activity, while huPON2 demonstrated the highest lactonase activity, followed by huPON3 and huPON1. A comparative assessment of the anti-biofilm potential of recombinant huPONs was conducted against Mycobacterium smegmatis, which revealed that all three paraoxonases inhibited biofilm formation; however, huPON2 displayed the highest anti-biofilm activity, followed by huPON3 and huPON1. Additionally, all the huPONs showed a synergistic effect with the conventional TB drug, Rifampicin, in enhancing biofilm disruption. These findings contribute valuable insights into the application of huPONs as a therapeutic tool against drug-resistant bacterial infections.},
}
RevDate: 2025-10-11
The use of double-reporter Mycobacterium abscessus strains to improve anti-biofilm drug screening.
Journal of microbiological methods pii:S0167-7012(25)00206-4 [Epub ahead of print].
Pulmonary infections caused by Mycobacterium abscessus are a pressing health issue due to the bacterium's high antibiotic resistance. Developing effective treatments is imperative, but conventional in vitro antibiotic susceptibility assays often do not correspond to clinical efficacy. M. abscessus easily aggregates and forms biofilms in various environments, where the protection conferred by an extracellular matrix, together with the mycobacteria's ability to enter a non-replicative persistent stage, highly hampers the activity of antibiotics. We developed a protocol to grow M. abscessus biofilms in a setup that allows high-throughput drug screening. The mycobacteria's luminescence is used as a readout of biofilm viability and its fluorescence as a measure of bacterial load, without the need for additional stains and maintaining the biofilm's integrity throughout the protocol. The use of imaging equipment allows a visual representation of the viability and bacterial load of each biofilm per well, and appropriate software can be used to quantify the luminescence and fluorescence signals. Quantification of biofilm mass can be done afterwards, using the same plate, by crystal violet staining. Although luminescent reporter assays have been used before, we believe this is the first time that a mycobacteria luminescent strain has been applied to assess drug activity against biofilms. This protocol enables the simultaneous screening of multiple compounds and identification of hits against M. abscessus biofilms in a fast, easy, and reliable manner. Most importantly, by mimicking the biofilm status that M. abscessus assumes in vivo, this assay will give more predictive information regarding compound efficacy.
Additional Links: PMID-41076142
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@article {pmid41076142,
year = {2025},
author = {Bento, CM and Gomes, MS and Silva, T},
title = {The use of double-reporter Mycobacterium abscessus strains to improve anti-biofilm drug screening.},
journal = {Journal of microbiological methods},
volume = {},
number = {},
pages = {107290},
doi = {10.1016/j.mimet.2025.107290},
pmid = {41076142},
issn = {1872-8359},
abstract = {Pulmonary infections caused by Mycobacterium abscessus are a pressing health issue due to the bacterium's high antibiotic resistance. Developing effective treatments is imperative, but conventional in vitro antibiotic susceptibility assays often do not correspond to clinical efficacy. M. abscessus easily aggregates and forms biofilms in various environments, where the protection conferred by an extracellular matrix, together with the mycobacteria's ability to enter a non-replicative persistent stage, highly hampers the activity of antibiotics. We developed a protocol to grow M. abscessus biofilms in a setup that allows high-throughput drug screening. The mycobacteria's luminescence is used as a readout of biofilm viability and its fluorescence as a measure of bacterial load, without the need for additional stains and maintaining the biofilm's integrity throughout the protocol. The use of imaging equipment allows a visual representation of the viability and bacterial load of each biofilm per well, and appropriate software can be used to quantify the luminescence and fluorescence signals. Quantification of biofilm mass can be done afterwards, using the same plate, by crystal violet staining. Although luminescent reporter assays have been used before, we believe this is the first time that a mycobacteria luminescent strain has been applied to assess drug activity against biofilms. This protocol enables the simultaneous screening of multiple compounds and identification of hits against M. abscessus biofilms in a fast, easy, and reliable manner. Most importantly, by mimicking the biofilm status that M. abscessus assumes in vivo, this assay will give more predictive information regarding compound efficacy.},
}
RevDate: 2025-10-11
CmpDate: 2025-10-11
Promising Biomarkers for Chronic Wound Healing: A Pilot Cohort Study on Wound Cytokines and a Novel Biofilm Detection Kit for Predicting 90-Day Outcomes.
Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society, 33(5):e70100.
Early identification of chronic wounds is essential for clinical decision-making in wound care. Biofilm infection is a well-known risk factor for delayed healing, while cytokines in the wound microenvironment play critical regulatory roles throughout the healing cascade. This single-centre prospective cohort study enrolled 66 patients with chronic wounds between 2020 and 2023 to evaluate cytokine biomarkers and biofilm detection tools for predicting wound outcomes. Clinical signs of biofilm (CSB) alone demonstrated limited predictive value, with accuracies of 66.7% for 30-day and 45.5% for 90-day healing. In contrast, the Wound Biofilm Detection Kit (WBDK) showed superior performance, achieving predictive accuracies of 92.4% and 60.6% for 30- and 90-day outcomes, respectively, outperforming both CSB and MolecuLight i:X. Cytokine analysis identified serum CRP, wound CRP and wound MCP-1 as significant predictors, with ROC analysis demonstrating good discriminative ability for wound CRP (AUC = 0.863) and wound MCP-1 (AUC = 0.830). A simplified Lasso regression model incorporating diabetes mellitus, peripheral arterial disease, wound location and WBDK grade achieved an AUC of 0.77 and an accuracy of 76% for 90-day outcomes. External validation was performed in 17 additional patients yielding a predictive accuracy of 76.5%, supporting the robustness of the model. These findings highlight the limited reliability of clinical signs alone and emphasise the value of objective biofilm detection and cytokine profiling in wound prognosis. Our high-accuracy prediction model, based on readily accessible clinical variables and WBDK results, may facilitate precision wound care and improve real-time management.
Additional Links: PMID-41074722
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PubMed:
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@article {pmid41074722,
year = {2025},
author = {Wu, YF and Sheu, SY and Cheng, NC and Cheng, CM},
title = {Promising Biomarkers for Chronic Wound Healing: A Pilot Cohort Study on Wound Cytokines and a Novel Biofilm Detection Kit for Predicting 90-Day Outcomes.},
journal = {Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society},
volume = {33},
number = {5},
pages = {e70100},
doi = {10.1111/wrr.70100},
pmid = {41074722},
issn = {1524-475X},
support = {111HCH092//National Taiwan University Hospital Hsin-Chu Branch/ ; 111HCH099//National Taiwan University Hospital Hsin-Chu Branch/ ; 113QF025E1//National Tsing Hua University/ ; 110-2222-E-002-013//National Science and Technology Council/ ; 112-2314-B-002-111//National Science and Technology Council/ ; 113-2314-B-002-098//National Science and Technology Council/ ; },
mesh = {Humans ; *Biofilms/growth & development ; *Wound Healing/physiology ; Male ; Female ; Biomarkers/metabolism ; Pilot Projects ; Prospective Studies ; *Cytokines/metabolism ; Middle Aged ; Aged ; Chronic Disease ; C-Reactive Protein/analysis ; *Wound Infection/microbiology/diagnosis ; Predictive Value of Tests ; *Wounds and Injuries ; },
abstract = {Early identification of chronic wounds is essential for clinical decision-making in wound care. Biofilm infection is a well-known risk factor for delayed healing, while cytokines in the wound microenvironment play critical regulatory roles throughout the healing cascade. This single-centre prospective cohort study enrolled 66 patients with chronic wounds between 2020 and 2023 to evaluate cytokine biomarkers and biofilm detection tools for predicting wound outcomes. Clinical signs of biofilm (CSB) alone demonstrated limited predictive value, with accuracies of 66.7% for 30-day and 45.5% for 90-day healing. In contrast, the Wound Biofilm Detection Kit (WBDK) showed superior performance, achieving predictive accuracies of 92.4% and 60.6% for 30- and 90-day outcomes, respectively, outperforming both CSB and MolecuLight i:X. Cytokine analysis identified serum CRP, wound CRP and wound MCP-1 as significant predictors, with ROC analysis demonstrating good discriminative ability for wound CRP (AUC = 0.863) and wound MCP-1 (AUC = 0.830). A simplified Lasso regression model incorporating diabetes mellitus, peripheral arterial disease, wound location and WBDK grade achieved an AUC of 0.77 and an accuracy of 76% for 90-day outcomes. External validation was performed in 17 additional patients yielding a predictive accuracy of 76.5%, supporting the robustness of the model. These findings highlight the limited reliability of clinical signs alone and emphasise the value of objective biofilm detection and cytokine profiling in wound prognosis. Our high-accuracy prediction model, based on readily accessible clinical variables and WBDK results, may facilitate precision wound care and improve real-time management.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Humans
*Biofilms/growth & development
*Wound Healing/physiology
Male
Female
Biomarkers/metabolism
Pilot Projects
Prospective Studies
*Cytokines/metabolism
Middle Aged
Aged
Chronic Disease
C-Reactive Protein/analysis
*Wound Infection/microbiology/diagnosis
Predictive Value of Tests
*Wounds and Injuries
RevDate: 2025-10-11
CmpDate: 2025-10-11
Characterization of Klebsiella pneumoniae Virulence and Biofilm Formation Patterns in Southwestern Nigeria.
Frontiers in bioscience (Elite edition), 17(3):37263.
BACKGROUND: Klebsiella pneumoniae possesses a range of virulence factors that enable this bacterium to colonize, persist, adhere to host tissues, invade, and cause disease. The pathogen poses a significant risk to immunocompromised individuals and those with pre-existing health conditions. This research focused on assessing the virulence traits and biofilm-forming abilities of K. pneumoniae isolates in Nigeria.
METHODS: Clinical samples were collected from 420 patients across seven tertiary hospitals in Southwestern Nigeria between February 2018 and July 2019. Standard microbiological procedures were employed to identify Klebsiella isolates. The presence of six specific virulence genes was determined using polymerase chain reaction (PCR): fimH, kfu, rmpA, uge, wcaG, and aero_1. Additionally, PCR was utilized to identify capsular serotypes K1, K2, and K5.
RESULTS: A substantial proportion (82%) of K. pneumoniae isolates demonstrated the ability to form biofilms. Of these, 51 isolates (39.8%) were classified as strong biofilm producers, 54 (42.2%) as moderate, and 23 (17.9%) showed no biofilm production. Among the virulence genes detected, uge was the most common (68.0%), followed by fimH (65.6%), aero_1 (63.3%), kfu (29.7%), rmpA (28.1%), and wcaG (14.1%). Statistically significant correlations were found between biofilm formation and the presence of aero_1, fimH, kfu, and rmpA. In terms of capsular serotypes, the majority of isolates were non-K1/K2/K5 (84.4%), with lower frequencies observed for K2 (7.0%), K1 (5.5%), and K5 (3.1%).
CONCLUSIONS: This study highlights that the aero_1, fimH, and uge genes are frequently present in K. pneumoniae isolates from this region, and that these strains often carry multiple virulence genes. The strong virulence potential and biofilm-forming capacity of these isolates underscore a significant public health threat, particularly in vulnerable populations.
Additional Links: PMID-41074464
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PubMed:
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@article {pmid41074464,
year = {2025},
author = {Odewale, G and Makanjuola, OB and Ojedele, RO and Abdulrahman, AA and Olowe, RA and Adefioye, OJ and Ojeniyi, FD and Ojurongbe, O and Olowe, OA},
title = {Characterization of Klebsiella pneumoniae Virulence and Biofilm Formation Patterns in Southwestern Nigeria.},
journal = {Frontiers in bioscience (Elite edition)},
volume = {17},
number = {3},
pages = {37263},
doi = {10.31083/FBE37263},
pmid = {41074464},
issn = {1945-0508},
mesh = {*Biofilms/growth & development ; *Klebsiella pneumoniae/pathogenicity/genetics/physiology ; Nigeria ; Humans ; Virulence/genetics ; Virulence Factors/genetics ; *Klebsiella Infections/microbiology ; },
abstract = {BACKGROUND: Klebsiella pneumoniae possesses a range of virulence factors that enable this bacterium to colonize, persist, adhere to host tissues, invade, and cause disease. The pathogen poses a significant risk to immunocompromised individuals and those with pre-existing health conditions. This research focused on assessing the virulence traits and biofilm-forming abilities of K. pneumoniae isolates in Nigeria.
METHODS: Clinical samples were collected from 420 patients across seven tertiary hospitals in Southwestern Nigeria between February 2018 and July 2019. Standard microbiological procedures were employed to identify Klebsiella isolates. The presence of six specific virulence genes was determined using polymerase chain reaction (PCR): fimH, kfu, rmpA, uge, wcaG, and aero_1. Additionally, PCR was utilized to identify capsular serotypes K1, K2, and K5.
RESULTS: A substantial proportion (82%) of K. pneumoniae isolates demonstrated the ability to form biofilms. Of these, 51 isolates (39.8%) were classified as strong biofilm producers, 54 (42.2%) as moderate, and 23 (17.9%) showed no biofilm production. Among the virulence genes detected, uge was the most common (68.0%), followed by fimH (65.6%), aero_1 (63.3%), kfu (29.7%), rmpA (28.1%), and wcaG (14.1%). Statistically significant correlations were found between biofilm formation and the presence of aero_1, fimH, kfu, and rmpA. In terms of capsular serotypes, the majority of isolates were non-K1/K2/K5 (84.4%), with lower frequencies observed for K2 (7.0%), K1 (5.5%), and K5 (3.1%).
CONCLUSIONS: This study highlights that the aero_1, fimH, and uge genes are frequently present in K. pneumoniae isolates from this region, and that these strains often carry multiple virulence genes. The strong virulence potential and biofilm-forming capacity of these isolates underscore a significant public health threat, particularly in vulnerable populations.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Klebsiella pneumoniae/pathogenicity/genetics/physiology
Nigeria
Humans
Virulence/genetics
Virulence Factors/genetics
*Klebsiella Infections/microbiology
RevDate: 2025-10-11
CmpDate: 2025-10-11
Starvation-induced metabolic adaptation of Bacillus cereus during biofilm formation: Phenotypic characterization and proteomic analysis.
Food research international (Ottawa, Ont.), 220:117167.
Bacillus cereus forms robust biofilms that enhance its persistence in food processing environments, leading to substantial safety risks and deterioration of dairy products. Nutrient availability is a vital factor to regulate biofilm formation; however, adaptive strategies of B. cereus under nutrient stress remain poorly understood. This study employs integrated phenotypic characterization and label-free quantitative proteomics to systematically decode the starvation-induced (in 1/10 TSB and 1/100 TSB) biofilm formation mechanism in B. cereus 12-1. The results showed that nutrient stress inhibited the growth of B. cereus 12-1 in its planktonic state, but increased its spore formation by 1.04 (1/10 TSB) and 1.79 (1/100 TSB) Log CFU/mL, protease production by 76.7 (1/10 TSB) and 140.37 U (1/100 TSB), cell surface hydrophobicity by 35.2 % (1/100 TSB), and self-aggregation capacity by 7.39 % (1/10 TSB) and 1.98 % (1/100 TSB). In addition, starvation induced its biofilm formation on stainless steel, resulting in elevated bacterial cell density within biofilms by 1.23 Log CFU/cm[2] (1/10 and 1/100 TSB), enhanced metabolic activity by 36.7 % (1/10 TSB) and 60.1 % (1/100 TSB). The confocal laser scanning microscopy results revealed more complex biofilm architectures with increased thickness by 3.54 % (1/10 TSB) and 35.2 % (1/100 TSB) and greater surface coverage of 52.46 (1/10 TSB) and 52.44 μm (1/100 TSB). Proteomics analysis identified 589 (in 1/10 TSB) and 442 (in 1/100 TSB) differentially expressed proteins (DEPs). These DEPs were mainly involved in 11 upregulated pathways, including quorum sensing, ATP-binding cassette (ABC) transporters, fatty acid degradation, several amino acid metabolic pathways, and oxidative phosphorylation, but were also significantly enriched in 12 downregulated pathways like ribosome, HIF-1 signaling pathway, nucleotide metabolism, and several carbohydrate metabolic pathways. In this regard, this investigation provides initial insights into the survival adaptation of B. cereus under nutrient stress conditions, serving as a foundational step toward understanding its stress responses and offering a preliminary scientific basis to inform future efforts aimed at mitigating biofilm-related risks in dairy processing environments.
Additional Links: PMID-41074349
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PubMed:
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@article {pmid41074349,
year = {2025},
author = {Yuan, L and Zhang, B and Dai, H and Miao, Y and Xu, Z and Yang, Z and Jiao, XA},
title = {Starvation-induced metabolic adaptation of Bacillus cereus during biofilm formation: Phenotypic characterization and proteomic analysis.},
journal = {Food research international (Ottawa, Ont.)},
volume = {220},
number = {},
pages = {117167},
doi = {10.1016/j.foodres.2025.117167},
pmid = {41074349},
issn = {1873-7145},
mesh = {*Biofilms/growth & development ; *Bacillus cereus/metabolism/physiology/growth & development ; *Proteomics/methods ; Bacterial Proteins/metabolism ; *Adaptation, Physiological ; Phenotype ; Spores, Bacterial/growth & development ; Gene Expression Regulation, Bacterial ; Food Microbiology ; },
abstract = {Bacillus cereus forms robust biofilms that enhance its persistence in food processing environments, leading to substantial safety risks and deterioration of dairy products. Nutrient availability is a vital factor to regulate biofilm formation; however, adaptive strategies of B. cereus under nutrient stress remain poorly understood. This study employs integrated phenotypic characterization and label-free quantitative proteomics to systematically decode the starvation-induced (in 1/10 TSB and 1/100 TSB) biofilm formation mechanism in B. cereus 12-1. The results showed that nutrient stress inhibited the growth of B. cereus 12-1 in its planktonic state, but increased its spore formation by 1.04 (1/10 TSB) and 1.79 (1/100 TSB) Log CFU/mL, protease production by 76.7 (1/10 TSB) and 140.37 U (1/100 TSB), cell surface hydrophobicity by 35.2 % (1/100 TSB), and self-aggregation capacity by 7.39 % (1/10 TSB) and 1.98 % (1/100 TSB). In addition, starvation induced its biofilm formation on stainless steel, resulting in elevated bacterial cell density within biofilms by 1.23 Log CFU/cm[2] (1/10 and 1/100 TSB), enhanced metabolic activity by 36.7 % (1/10 TSB) and 60.1 % (1/100 TSB). The confocal laser scanning microscopy results revealed more complex biofilm architectures with increased thickness by 3.54 % (1/10 TSB) and 35.2 % (1/100 TSB) and greater surface coverage of 52.46 (1/10 TSB) and 52.44 μm (1/100 TSB). Proteomics analysis identified 589 (in 1/10 TSB) and 442 (in 1/100 TSB) differentially expressed proteins (DEPs). These DEPs were mainly involved in 11 upregulated pathways, including quorum sensing, ATP-binding cassette (ABC) transporters, fatty acid degradation, several amino acid metabolic pathways, and oxidative phosphorylation, but were also significantly enriched in 12 downregulated pathways like ribosome, HIF-1 signaling pathway, nucleotide metabolism, and several carbohydrate metabolic pathways. In this regard, this investigation provides initial insights into the survival adaptation of B. cereus under nutrient stress conditions, serving as a foundational step toward understanding its stress responses and offering a preliminary scientific basis to inform future efforts aimed at mitigating biofilm-related risks in dairy processing environments.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Bacillus cereus/metabolism/physiology/growth & development
*Proteomics/methods
Bacterial Proteins/metabolism
*Adaptation, Physiological
Phenotype
Spores, Bacterial/growth & development
Gene Expression Regulation, Bacterial
Food Microbiology
RevDate: 2025-10-11
CmpDate: 2025-10-11
Slightly acidic electrolyzed water induces Staphylococcus aureus to enter the VBNC state: differences between planktonic and biofilm states bacteria.
Food research international (Ottawa, Ont.), 220:117124.
S. aureus is a common foodborne pathogen that poses a great danger to the food industry and human health. Slightly acidic electrolytic water (SAEW) is characterized by strong antimicrobial effect and high potential for application. In this study, the effect of SAEW on the formation of VBNC state of S. aureus was systematically evaluated, and the differences in the formation of VBNC state of S. aureus in planktonic and biofilm states were also analyzed by flow cytometry. The results showed that treatment of S. aureus in planktonic and biofilm states with 0.8 mg/L SAEW resulted in complete loss of culturability at 2.5 h and 2.0 h, respectively, with 3.56 ± 0.28 % and 4.81 ± 0.13 % of cells formed VBNC state. And both states of VBNC S. aureus could be resuscitated, and the planktonic VBNC state S. aureus resuscitated faster. ATP concentration, ROS level and respiration intensity of different states of bacteria were examined, compared with uninduced bacteria, VBNC S. aureus showed increased ATP concentration and ROS level, and decreased catalase activity, esterase activity, and respiratory intensity. Meanwhile, the overall metabolic level of the biofilm VBNC state bacteria was lower than that of the planktonic VBNC state bacteria, and its ROS level was higher than that of the planktonic VBNC state bacteria. Gene expression was determined by RT-qPCR, and the results showed that the transcript levels of genes regulating N-acetylglucosamine metabolism were up-regulated and those related to lipid metabolism, antioxidant and respiratory metabolism were down-regulated in the VBNC state S. aureus. This study comprehensively evaluates the application effect of SAEW in the food industry to provide a scientific basis for its safe and effective use; deepens the understanding of the mechanism of the formation of VBNC states by bacteria in different states, and provides theoretical support for the control of VBNC bacteria.
Additional Links: PMID-41074327
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PubMed:
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@article {pmid41074327,
year = {2025},
author = {Zhang, Z and Feng, J and Cui, H and Wu, Y and Wang, Y and Xu, W and Lu, Y and Duan, M and Yang, H and Cheng, S and Cai, X and Zhang, C and Shi, C},
title = {Slightly acidic electrolyzed water induces Staphylococcus aureus to enter the VBNC state: differences between planktonic and biofilm states bacteria.},
journal = {Food research international (Ottawa, Ont.)},
volume = {220},
number = {},
pages = {117124},
doi = {10.1016/j.foodres.2025.117124},
pmid = {41074327},
issn = {1873-7145},
mesh = {*Biofilms/drug effects/growth & development ; *Staphylococcus aureus/drug effects/growth & development/physiology/metabolism/genetics ; *Plankton/drug effects ; Electrolysis ; *Water/pharmacology/chemistry ; Hydrogen-Ion Concentration ; Food Microbiology ; Reactive Oxygen Species/metabolism ; Adenosine Triphosphate/metabolism ; Microbial Viability/drug effects ; },
abstract = {S. aureus is a common foodborne pathogen that poses a great danger to the food industry and human health. Slightly acidic electrolytic water (SAEW) is characterized by strong antimicrobial effect and high potential for application. In this study, the effect of SAEW on the formation of VBNC state of S. aureus was systematically evaluated, and the differences in the formation of VBNC state of S. aureus in planktonic and biofilm states were also analyzed by flow cytometry. The results showed that treatment of S. aureus in planktonic and biofilm states with 0.8 mg/L SAEW resulted in complete loss of culturability at 2.5 h and 2.0 h, respectively, with 3.56 ± 0.28 % and 4.81 ± 0.13 % of cells formed VBNC state. And both states of VBNC S. aureus could be resuscitated, and the planktonic VBNC state S. aureus resuscitated faster. ATP concentration, ROS level and respiration intensity of different states of bacteria were examined, compared with uninduced bacteria, VBNC S. aureus showed increased ATP concentration and ROS level, and decreased catalase activity, esterase activity, and respiratory intensity. Meanwhile, the overall metabolic level of the biofilm VBNC state bacteria was lower than that of the planktonic VBNC state bacteria, and its ROS level was higher than that of the planktonic VBNC state bacteria. Gene expression was determined by RT-qPCR, and the results showed that the transcript levels of genes regulating N-acetylglucosamine metabolism were up-regulated and those related to lipid metabolism, antioxidant and respiratory metabolism were down-regulated in the VBNC state S. aureus. This study comprehensively evaluates the application effect of SAEW in the food industry to provide a scientific basis for its safe and effective use; deepens the understanding of the mechanism of the formation of VBNC states by bacteria in different states, and provides theoretical support for the control of VBNC bacteria.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Staphylococcus aureus/drug effects/growth & development/physiology/metabolism/genetics
*Plankton/drug effects
Electrolysis
*Water/pharmacology/chemistry
Hydrogen-Ion Concentration
Food Microbiology
Reactive Oxygen Species/metabolism
Adenosine Triphosphate/metabolism
Microbial Viability/drug effects
RevDate: 2025-10-11
Candida auris promotes Pseudomonas aeruginosa tolerance to meropenem in a mature dual-species biofilm.
Microbes and infection pii:S1286-4579(25)00098-X [Epub ahead of print].
Co-infections involving Pseudomonas aeruginosa and Candida auris are becoming increasingly common in hospitals and represent an emerging clinical challenge, as these pathogens can form mixed biofilms during catheter-associated infections, which complicates treatment, prolongs the disease and poses a significant threat to public health. In this study, we formed individual- and dual-species biofilms with Pseudomonas aeruginosa and Candida auris, and then treated mature biofilms with or without meropenem to determine the number of viable cells (colony-forming units). Moreover, Pseudomonas aeruginosa biofilms plus total or fractionated Candida auris supernatant were exposed to meropenem to calculate biofilm-associated viable cells. The results showed that Pseudomonas aeruginosa exhibits increased survival to meropenem in dual-species biofilms compared to individual-species biofilms. Furthermore, we demonstrated that the molecule that promotes meropenem tolerance is present in the supernatant of Candida auris biofilms with a molecular mass <10 kDa. In conclusion, Candida auris induces meropenem tolerance in Pseudomonas aeruginosa during mixed biofilms.
Additional Links: PMID-41072755
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PubMed:
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@article {pmid41072755,
year = {2025},
author = {Flores-Maldonado, O and Garza-Velásquez, MF and Becerril-García, MA and Ríos-López, AL},
title = {Candida auris promotes Pseudomonas aeruginosa tolerance to meropenem in a mature dual-species biofilm.},
journal = {Microbes and infection},
volume = {},
number = {},
pages = {105566},
doi = {10.1016/j.micinf.2025.105566},
pmid = {41072755},
issn = {1769-714X},
abstract = {Co-infections involving Pseudomonas aeruginosa and Candida auris are becoming increasingly common in hospitals and represent an emerging clinical challenge, as these pathogens can form mixed biofilms during catheter-associated infections, which complicates treatment, prolongs the disease and poses a significant threat to public health. In this study, we formed individual- and dual-species biofilms with Pseudomonas aeruginosa and Candida auris, and then treated mature biofilms with or without meropenem to determine the number of viable cells (colony-forming units). Moreover, Pseudomonas aeruginosa biofilms plus total or fractionated Candida auris supernatant were exposed to meropenem to calculate biofilm-associated viable cells. The results showed that Pseudomonas aeruginosa exhibits increased survival to meropenem in dual-species biofilms compared to individual-species biofilms. Furthermore, we demonstrated that the molecule that promotes meropenem tolerance is present in the supernatant of Candida auris biofilms with a molecular mass <10 kDa. In conclusion, Candida auris induces meropenem tolerance in Pseudomonas aeruginosa during mixed biofilms.},
}
RevDate: 2025-10-10
Inhibition of biofilm formation and virulence factors of Pseudomonas aeruginosa by ciprofloxacin-loaded ZnO@lignin@chitosan nanoparticles.
International journal of biological macromolecules pii:S0141-8130(25)08750-1 [Epub ahead of print].
The rapid development of antimicrobial resistance (AMR) in bacterial infections leads to increased mortality and reduced treatment effectiveness. Given the urgent need for multifunctional therapeutic agents capable of overcoming AMR, we developed a novel ZnO@lignin@chitosan nanocomposite loaded with ciprofloxacin (CIP), in which the synergistic combination of ZnO, lignin, and chitosan enhances antibacterial, antibiofilm, antivirulence, and antioxidant performance. The synthesized nanocomposite was characterized using various techniques, including Fourier transform infrared spectroscopy (FT-IR), UV-visible spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) analysis, elemental mapping (MAP), field emission transmission electron microscopy (FE-TEM), and X-ray photoelectron spectroscopy (XPS). The ZnO@lignin@chitosan@CIP nanocomposite exhibited pH-responsive drug release, with accelerated release in acidic environments mimicking infection sites. The synergistic combination of its components enhanced multifunctional performance: lignin acted as an antioxidant, chitosan improved drug loading, biocompatibility, and inherent antibacterial activity against Gram-positive, Gram-negative, and the fungal strain Candida albicans, while ZnO nanoparticles (NPs) contributed additional antimicrobial effects. Furthermore, the nanocomposite effectively inhibited Pseudomonas aeruginosa (P. aeruginosa) biofilm formation and suppressed virulence factors, including protease, pyocyanin, and pyoverdine at sub-minimum inhibitory concentrations (sub-MICs). Moreover, gene expression analysis revealed downregulation of key quorum-sensing regulators (lasI, lasR, rhlI, and rhlR), indicating the composite's molecular antivirulence potential. These findings demonstrate that the unique synergy of ZnO, lignin, and chitosan provides multifunctional advantages, making ZnO@lignin@chitosan@CIP a promising candidate for combating drug-resistant and biofilm-associated infections.
Additional Links: PMID-41072690
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PubMed:
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@article {pmid41072690,
year = {2025},
author = {Fattahi, N and Tabassum, N and Khan, F and Kim, NG and Kim, YM and Lee, B and Lee, SJ and Je, JY and Park, WS and Choi, IW and Linh, NV and Jung, WK},
title = {Inhibition of biofilm formation and virulence factors of Pseudomonas aeruginosa by ciprofloxacin-loaded ZnO@lignin@chitosan nanoparticles.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {148193},
doi = {10.1016/j.ijbiomac.2025.148193},
pmid = {41072690},
issn = {1879-0003},
abstract = {The rapid development of antimicrobial resistance (AMR) in bacterial infections leads to increased mortality and reduced treatment effectiveness. Given the urgent need for multifunctional therapeutic agents capable of overcoming AMR, we developed a novel ZnO@lignin@chitosan nanocomposite loaded with ciprofloxacin (CIP), in which the synergistic combination of ZnO, lignin, and chitosan enhances antibacterial, antibiofilm, antivirulence, and antioxidant performance. The synthesized nanocomposite was characterized using various techniques, including Fourier transform infrared spectroscopy (FT-IR), UV-visible spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) analysis, elemental mapping (MAP), field emission transmission electron microscopy (FE-TEM), and X-ray photoelectron spectroscopy (XPS). The ZnO@lignin@chitosan@CIP nanocomposite exhibited pH-responsive drug release, with accelerated release in acidic environments mimicking infection sites. The synergistic combination of its components enhanced multifunctional performance: lignin acted as an antioxidant, chitosan improved drug loading, biocompatibility, and inherent antibacterial activity against Gram-positive, Gram-negative, and the fungal strain Candida albicans, while ZnO nanoparticles (NPs) contributed additional antimicrobial effects. Furthermore, the nanocomposite effectively inhibited Pseudomonas aeruginosa (P. aeruginosa) biofilm formation and suppressed virulence factors, including protease, pyocyanin, and pyoverdine at sub-minimum inhibitory concentrations (sub-MICs). Moreover, gene expression analysis revealed downregulation of key quorum-sensing regulators (lasI, lasR, rhlI, and rhlR), indicating the composite's molecular antivirulence potential. These findings demonstrate that the unique synergy of ZnO, lignin, and chitosan provides multifunctional advantages, making ZnO@lignin@chitosan@CIP a promising candidate for combating drug-resistant and biofilm-associated infections.},
}
RevDate: 2025-10-10
Improving Biofilm Prevention in Implant-Based Breast Surgery: Hyaluronic Acid as an Implant Submersion Adjunct.
Annals of plastic surgery [Epub ahead of print].
PURPOSE: Capsular contracture is a common major complication of implant-based breast surgery. Although its etiology is incompletely understood, biofilm formation on implant surfaces is considered a central factor. Plastic surgeons have adopted many risk-reducing measures; however, these measures are heterogeneous, and capsular contracture rates remain high. Recent studies have demonstrated the antibiofilm effects of hyaluronic acid on various surgical prostheses. Our study tests the in vitro antibiofilm properties of hyaluronic acid as a breast implant submersion adjunct.
METHODS: Six-millimeter-diameter silicone disks were cut from smooth tissue expanders and treated with different concentrations of hyaluronic acid alone or combined with triple antibiotic solution (clindamycin, cefazolin, and gentamicin at 450, 1000, and 80 mg/mL, respectively). Following treatment, the disks were submerged in tryptic soy broth inoculated with Staphylococcus epidermidis strain RP62A and incubated for 60 hours to allow biofilm formation. Biofilms were stained with crystal violet, and the stain was extracted to measure optical density as a marker of biofilm formation.
RESULTS: Hyaluronic acid submersion exerted dose-dependent antibiofilm effects; hyaluronic acid 1.2% (wt/vol) solution produced a biofilm reduction similar to that achieved by the triple antibiotic solution. Synergistic effects were observed in the combination treatments, with hyaluronic acid 0.8% (wt/vol) in triple antibiotic solution producing the greatest biofilm reduction. This treatment produced a mean optical density of 0.313, which is significantly lower than that of the positive control (2.539; P < 0.001) and triple antibiotic solution alone (0.877; P < 0.001). These findings represent biofilm reductions of 87.7% and 64.3%, respectively.
CONCLUSION: Hyaluronic acid shows potential as an adjunct to triple antibiotic breast implant submersion. Pretreating silicone disks with hyaluronic acid 0.8% (wt/vol) in triple antibiotic solution led to biofilm reductions of 87.7% and 64.3% compared with the positive control and the triple antibiotic solution, respectively. These effects, combined with hyaluronic acid's biocompatibility, resorbability, and viscosity, demonstrate its promise for the prevention of capsular contracture in implant-based breast surgery.
Additional Links: PMID-41071864
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@article {pmid41071864,
year = {2025},
author = {Larson, JM and Johnson, MS and Myint, JA and Gupta, SC},
title = {Improving Biofilm Prevention in Implant-Based Breast Surgery: Hyaluronic Acid as an Implant Submersion Adjunct.},
journal = {Annals of plastic surgery},
volume = {},
number = {},
pages = {},
pmid = {41071864},
issn = {1536-3708},
abstract = {PURPOSE: Capsular contracture is a common major complication of implant-based breast surgery. Although its etiology is incompletely understood, biofilm formation on implant surfaces is considered a central factor. Plastic surgeons have adopted many risk-reducing measures; however, these measures are heterogeneous, and capsular contracture rates remain high. Recent studies have demonstrated the antibiofilm effects of hyaluronic acid on various surgical prostheses. Our study tests the in vitro antibiofilm properties of hyaluronic acid as a breast implant submersion adjunct.
METHODS: Six-millimeter-diameter silicone disks were cut from smooth tissue expanders and treated with different concentrations of hyaluronic acid alone or combined with triple antibiotic solution (clindamycin, cefazolin, and gentamicin at 450, 1000, and 80 mg/mL, respectively). Following treatment, the disks were submerged in tryptic soy broth inoculated with Staphylococcus epidermidis strain RP62A and incubated for 60 hours to allow biofilm formation. Biofilms were stained with crystal violet, and the stain was extracted to measure optical density as a marker of biofilm formation.
RESULTS: Hyaluronic acid submersion exerted dose-dependent antibiofilm effects; hyaluronic acid 1.2% (wt/vol) solution produced a biofilm reduction similar to that achieved by the triple antibiotic solution. Synergistic effects were observed in the combination treatments, with hyaluronic acid 0.8% (wt/vol) in triple antibiotic solution producing the greatest biofilm reduction. This treatment produced a mean optical density of 0.313, which is significantly lower than that of the positive control (2.539; P < 0.001) and triple antibiotic solution alone (0.877; P < 0.001). These findings represent biofilm reductions of 87.7% and 64.3%, respectively.
CONCLUSION: Hyaluronic acid shows potential as an adjunct to triple antibiotic breast implant submersion. Pretreating silicone disks with hyaluronic acid 0.8% (wt/vol) in triple antibiotic solution led to biofilm reductions of 87.7% and 64.3% compared with the positive control and the triple antibiotic solution, respectively. These effects, combined with hyaluronic acid's biocompatibility, resorbability, and viscosity, demonstrate its promise for the prevention of capsular contracture in implant-based breast surgery.},
}
RevDate: 2025-10-10
Aquatic Biofilm as a Hotspot for Manganese Oxidation Enabled by Microbial Extracellular Matrix-Mediated Dual-Pathway Electron Transfer.
Environmental science & technology [Epub ahead of print].
Manganese(II) oxidation governs the geochemical cycles of numerous elements owing to the exceptional oxidation and adsorption properties of resultant manganese oxide minerals. This process is predominantly thought to be driven by microorganisms using cellular oxidoreductases. Herein, we uncovered a new pathway for microbial manganese(II) oxidation mediated by a biofilm extracellular matrix, i.e., extracellular polymeric substances (EPS) secreted by microorganisms. Owing to abundant EPS, the biofilm emerged as a hotspot for manganese(II) oxidation in a sunlit aquatic system, and its ability to oxidize manganese(II) was 2.9 times higher than that of free microorganisms when normalized by the cell number. Both oxidoreductases such as NAD(P)H-oxidizing enzymes and nonenzymatic redox components like flavins and quinones in the EPS mediated electron transfer from intracellular NADPH to oxygen to produce superoxide. Additionally, quinones within the EPS under light irradiation mediated electron transfer from reducing moieties (e.g., thiols and phenols) in the extracellular matrix to oxygen to generate superoxide. As a result, EPS boosted manganese(II) oxidation via superoxide generated by these two electron transfer pathways. This biofilm-driven rapid manganese(II) oxidation process was found to be prevalent across diverse sunlit aquatic environments. This study expands the framework of microbe-driven cycling of manganese as well as other elements in nature.
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@article {pmid41071745,
year = {2025},
author = {Yao, MC and Huang, Q and Xie, HX and Zhang, X and Sheng, GP},
title = {Aquatic Biofilm as a Hotspot for Manganese Oxidation Enabled by Microbial Extracellular Matrix-Mediated Dual-Pathway Electron Transfer.},
journal = {Environmental science & technology},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.est.5c09864},
pmid = {41071745},
issn = {1520-5851},
abstract = {Manganese(II) oxidation governs the geochemical cycles of numerous elements owing to the exceptional oxidation and adsorption properties of resultant manganese oxide minerals. This process is predominantly thought to be driven by microorganisms using cellular oxidoreductases. Herein, we uncovered a new pathway for microbial manganese(II) oxidation mediated by a biofilm extracellular matrix, i.e., extracellular polymeric substances (EPS) secreted by microorganisms. Owing to abundant EPS, the biofilm emerged as a hotspot for manganese(II) oxidation in a sunlit aquatic system, and its ability to oxidize manganese(II) was 2.9 times higher than that of free microorganisms when normalized by the cell number. Both oxidoreductases such as NAD(P)H-oxidizing enzymes and nonenzymatic redox components like flavins and quinones in the EPS mediated electron transfer from intracellular NADPH to oxygen to produce superoxide. Additionally, quinones within the EPS under light irradiation mediated electron transfer from reducing moieties (e.g., thiols and phenols) in the extracellular matrix to oxygen to generate superoxide. As a result, EPS boosted manganese(II) oxidation via superoxide generated by these two electron transfer pathways. This biofilm-driven rapid manganese(II) oxidation process was found to be prevalent across diverse sunlit aquatic environments. This study expands the framework of microbe-driven cycling of manganese as well as other elements in nature.},
}
RevDate: 2025-10-10
Inhibition of Biofilm Formation and Cell Wall Targeting Activity of Endophytic Nocardiopsis Strain KDCGRAW Isolated From the Indian Sundarbans.
Chemistry & biodiversity [Epub ahead of print].
The discovery of new antimicrobials is one of the most crucial approaches to tackling the antimicrobial resistance crisis. Strain KDCGRAW was isolated from the root of Rhizophora apiculata (Garjan tree) from the Bonnie camp subdivision of Sundarbans, West Bengal, India. 16S rRNA gene sequencing analysis revealed that the strain belongs to the genus Nocardiopsis. The strain was subjected to fermentation, and the crude extract was analyzed using GC-MS. The extract inhibited Escherichia coli MTCC 1195 biofilm formation and showed a percentage biofilm remaining of 77.69% for 1/2 MIC, 69.18% for MIC, and 51.56% for 2 MIC, respectively. However, MIC and 2 MIC doses of the extract showed a significant biofilm formation inhibition and the percentage biofilm remaining determined was 51.89% and 43.97%, respectively, as compared to the 1/2 MIC 74.93% against Staphylococcus aureus MTCC 2940. The in silico docking and molecular dynamics study revealed that compound 1 and compound 9 exhibited the best docking energies with the two selected biofilm-associated proteins, achieving binding energies of -6.84 and -7.7 kcal/mol on 5XP0 and 7C7R, respectively. In vivo toxicity analysis using brine shrimp revealed that the extract was nontoxic at all the concentration ranges, namely, 1/2 MIC, MIC, and 2 MIC.
Additional Links: PMID-41071733
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@article {pmid41071733,
year = {2025},
author = {Paul, P and Dolui, S and Ireen, S and Bisoi, S and Palai, S and Biswas, P and Mazumder, K and Biswas, K},
title = {Inhibition of Biofilm Formation and Cell Wall Targeting Activity of Endophytic Nocardiopsis Strain KDCGRAW Isolated From the Indian Sundarbans.},
journal = {Chemistry & biodiversity},
volume = {},
number = {},
pages = {e01947},
doi = {10.1002/cbdv.202501947},
pmid = {41071733},
issn = {1612-1880},
support = {IIRP/SG-7856/2023//Indian Council of Medical Research (ICMR), New Delhi/ ; },
abstract = {The discovery of new antimicrobials is one of the most crucial approaches to tackling the antimicrobial resistance crisis. Strain KDCGRAW was isolated from the root of Rhizophora apiculata (Garjan tree) from the Bonnie camp subdivision of Sundarbans, West Bengal, India. 16S rRNA gene sequencing analysis revealed that the strain belongs to the genus Nocardiopsis. The strain was subjected to fermentation, and the crude extract was analyzed using GC-MS. The extract inhibited Escherichia coli MTCC 1195 biofilm formation and showed a percentage biofilm remaining of 77.69% for 1/2 MIC, 69.18% for MIC, and 51.56% for 2 MIC, respectively. However, MIC and 2 MIC doses of the extract showed a significant biofilm formation inhibition and the percentage biofilm remaining determined was 51.89% and 43.97%, respectively, as compared to the 1/2 MIC 74.93% against Staphylococcus aureus MTCC 2940. The in silico docking and molecular dynamics study revealed that compound 1 and compound 9 exhibited the best docking energies with the two selected biofilm-associated proteins, achieving binding energies of -6.84 and -7.7 kcal/mol on 5XP0 and 7C7R, respectively. In vivo toxicity analysis using brine shrimp revealed that the extract was nontoxic at all the concentration ranges, namely, 1/2 MIC, MIC, and 2 MIC.},
}
RevDate: 2025-10-10
Long-term culturing of Pseudomonas aeruginosa in static, minimal nutrient medium results in increased pyocyanin production, reduced biofilm production, and loss of motility.
Applied and environmental microbiology [Epub ahead of print].
Pseudomonas aeruginosa is a multidrug-resistant opportunistic human pathogen that can survive in many natural and anthropogenic environments. It is a leading cause of morbidity in individuals with cystic fibrosis and is one of the most prevalent pathogens associated with nosocomial infections in the United States. It has been shown that this organism can survive and persist in low-nutrient environments, such as sink drains. How adaptation to these types of environments influences the phenotypic traits of this organism has not been well studied. Here, we implemented an experimental evolution system in which six strains of P. aeruginosa were subjected to low-nutrient conditions over the course of 12 weeks and assessed phenotypic and genotypic changes that occurred as a result of adaptation to such environments. We observed that adaptation to low-nutrient environments resulted in decreased generation time, reduced cell size, reduced biofilm formation, increased pyocyanin production, and decreased motility for some of the strains. Furthermore, some of the evolved isolates were significantly more virulent/competitive against a phagocytic predator. This study is significant as it allows us to predict how this organism will evolve in hospital and domestic environments and can help us improve treatment options for patients.IMPORTANCEHuman commensal and pathogenic organisms undergo dynamic cycles across human and non-human environments. Despite the crucial implications for human health, the understanding of bacterial adaptations to these diverse environments and their subsequent impact on human-bacterial interactions remains underexplored. This study shows how Pseudomonas aeruginosa, an opportunistic human pathogen, adapts phenotypically in response to a shift from high nutrients (like those found in the human body) to low nutrients (like those found in many other environments, like sink drains). This work also shows that, in some cases, resistance to predatory forces can evolve in the absence of a predator. This work is important as it contributes to the growing body of knowledge concerning how external, non-host-related abiotic conditions influence host-pathogen interactions.
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@article {pmid41070941,
year = {2025},
author = {Cecil, RE and Ornelas, E and Phan, A and Medina-Chavez, NO and Travisano, M and Yoder-Himes, DR},
title = {Long-term culturing of Pseudomonas aeruginosa in static, minimal nutrient medium results in increased pyocyanin production, reduced biofilm production, and loss of motility.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0097525},
doi = {10.1128/aem.00975-25},
pmid = {41070941},
issn = {1098-5336},
abstract = {Pseudomonas aeruginosa is a multidrug-resistant opportunistic human pathogen that can survive in many natural and anthropogenic environments. It is a leading cause of morbidity in individuals with cystic fibrosis and is one of the most prevalent pathogens associated with nosocomial infections in the United States. It has been shown that this organism can survive and persist in low-nutrient environments, such as sink drains. How adaptation to these types of environments influences the phenotypic traits of this organism has not been well studied. Here, we implemented an experimental evolution system in which six strains of P. aeruginosa were subjected to low-nutrient conditions over the course of 12 weeks and assessed phenotypic and genotypic changes that occurred as a result of adaptation to such environments. We observed that adaptation to low-nutrient environments resulted in decreased generation time, reduced cell size, reduced biofilm formation, increased pyocyanin production, and decreased motility for some of the strains. Furthermore, some of the evolved isolates were significantly more virulent/competitive against a phagocytic predator. This study is significant as it allows us to predict how this organism will evolve in hospital and domestic environments and can help us improve treatment options for patients.IMPORTANCEHuman commensal and pathogenic organisms undergo dynamic cycles across human and non-human environments. Despite the crucial implications for human health, the understanding of bacterial adaptations to these diverse environments and their subsequent impact on human-bacterial interactions remains underexplored. This study shows how Pseudomonas aeruginosa, an opportunistic human pathogen, adapts phenotypically in response to a shift from high nutrients (like those found in the human body) to low nutrients (like those found in many other environments, like sink drains). This work also shows that, in some cases, resistance to predatory forces can evolve in the absence of a predator. This work is important as it contributes to the growing body of knowledge concerning how external, non-host-related abiotic conditions influence host-pathogen interactions.},
}
RevDate: 2025-10-10
CmpDate: 2025-10-10
Development of Metal Analogues of Prussian Blue@Silver Nanocomposites for the Treatment of Biofilm and Skin-Infections.
APMIS : acta pathologica, microbiologica, et immunologica Scandinavica, 133(10):e70073.
Silver-based nanocomplexes are promising antibacterial agents because of their ability to break the bacterial cell membrane, enhance oxidative stress, and damage bacterial DNA, offering potential alternatives to conventional antibiotics. Recently, Prussian blue analogues nanocomposites have gained attention due to their unique advantages, including biocompatibility, low cost, and easy structural modification to induce bioactivity. Herein, we developed different metal analogues of Prussian blue@silver [M[II]PB@Ag, M[II] = Cu, Co, and Mn] nanocomposites for antibacterial applications. In vitro assays confirmed the utility of these materials in inhibiting Gram-negative and Gram-positive bacteria. The antibiofilm property of CuIIPB@Ag and MnIIPB@Ag was assessed by coating them on PDMS disk surfaces. The results show that CuPB@Ag (at 1600 μM) and MnPB@Ag (at 4000 μM) achieve approximately an 85% reduction in biofilm formation. In vitro cytotoxicity studies assessed by using the MTT assay support the biocompatibility of Cu[II]PB@Ag (up to 80% cell viability in 60 μM) and Mn[II]PB@Ag (up to 70% cell viability in 150 μM). Moreover, Cu[II]PB@Ag (at 1600 μM) and Mn[II]PB@Ag (at 4000 μM) eliminated in vivo skin infections in the preclinical rat model. These results highlight the potential of these metal analogues of Prussian blue@silver nanocomposites for the treatment of bacterial infections.
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@article {pmid41069253,
year = {2025},
author = {Kumari, S and Bhukya, S and Upadhyay, A and Londhe, S and Nuthi, S and Patra, CR and Mukherjee, S},
title = {Development of Metal Analogues of Prussian Blue@Silver Nanocomposites for the Treatment of Biofilm and Skin-Infections.},
journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica},
volume = {133},
number = {10},
pages = {e70073},
doi = {10.1111/apm.70073},
pmid = {41069253},
issn = {1600-0463},
support = {CSC0302//CSC0302, sponsored by CSIR, New Delhi to CRP/ ; BT/PR49530/MED/32/839/2023//Department of Biotechnology, Ministry of Science and Technology, India/ ; },
mesh = {*Biofilms/drug effects ; *Ferrocyanides/chemistry/pharmacology ; *Nanocomposites/chemistry ; *Silver/chemistry/pharmacology ; Animals ; *Anti-Bacterial Agents/pharmacology/chemistry ; Rats ; Humans ; Microbial Sensitivity Tests ; Cell Survival/drug effects ; Gram-Positive Bacteria/drug effects ; *Skin Diseases, Bacterial/drug therapy ; },
abstract = {Silver-based nanocomplexes are promising antibacterial agents because of their ability to break the bacterial cell membrane, enhance oxidative stress, and damage bacterial DNA, offering potential alternatives to conventional antibiotics. Recently, Prussian blue analogues nanocomposites have gained attention due to their unique advantages, including biocompatibility, low cost, and easy structural modification to induce bioactivity. Herein, we developed different metal analogues of Prussian blue@silver [M[II]PB@Ag, M[II] = Cu, Co, and Mn] nanocomposites for antibacterial applications. In vitro assays confirmed the utility of these materials in inhibiting Gram-negative and Gram-positive bacteria. The antibiofilm property of CuIIPB@Ag and MnIIPB@Ag was assessed by coating them on PDMS disk surfaces. The results show that CuPB@Ag (at 1600 μM) and MnPB@Ag (at 4000 μM) achieve approximately an 85% reduction in biofilm formation. In vitro cytotoxicity studies assessed by using the MTT assay support the biocompatibility of Cu[II]PB@Ag (up to 80% cell viability in 60 μM) and Mn[II]PB@Ag (up to 70% cell viability in 150 μM). Moreover, Cu[II]PB@Ag (at 1600 μM) and Mn[II]PB@Ag (at 4000 μM) eliminated in vivo skin infections in the preclinical rat model. These results highlight the potential of these metal analogues of Prussian blue@silver nanocomposites for the treatment of bacterial infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
*Ferrocyanides/chemistry/pharmacology
*Nanocomposites/chemistry
*Silver/chemistry/pharmacology
Animals
*Anti-Bacterial Agents/pharmacology/chemistry
Rats
Humans
Microbial Sensitivity Tests
Cell Survival/drug effects
Gram-Positive Bacteria/drug effects
*Skin Diseases, Bacterial/drug therapy
RevDate: 2025-10-09
CmpDate: 2025-10-10
Utilizing the effectiveness of phage cocktail to combat Shigella and Salmonella infections and their polymicrobial biofilm control activity.
BMC microbiology, 25(1):649.
BACKGROUND: Shigella and Salmonella are major foodborne and waterborne pathogens responsible for acute gastrointestinal infections and significant global morbidity and mortality. Both species are capable of forming bacterial biofilms in the food processing industry, a key survival mechanism that significantly reduces the effectiveness of antibacterial drugs. The global rise in antimicrobial resistance (AMR) necessitates the urgent development of new strategies. Bacteriophages, particularly phage cocktails, provide a potential alternative because of their host specificity and ability to degrade biofilms.
RESULTS: In this study, a new bacteriophage, Sspk23, infecting Shigella sonnei, was isolated from lake water and biologically characterized to assess its lytic activity and stability under varying conditions. Furthermore, this study investigates the effectiveness of a phage cocktail, including a newly isolated Sspk23 and two previously identified phages, Sfk20 and STWB21, against Shigella and Salmonella infections with a focus on its ability to combat single and polymicrobial infections. The biofilm removal potential of the phage cocktail was observed using Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM), and also quantitatively assessed in a microtiter plate. Cytotoxicity tests were conducted on human adherent epithelial cell line and macrophage cell line to confirm the safety of the phage and phage cocktail for therapeutic use.
CONCLUSIONS: The findings demonstrate the possibility of a phage cocktail as a substitute for conventional antibiotics in controlling Shigella and Salmonella infections. Additionally, their capacity to destroy biofilms indicates potential applications in clinical therapies, environmental remediation, and food safety. Future studies will be focused on phage-antibiotic synergy optimization and in vivo validation to combat multidrug-resistant (MDR) bacteria.
Additional Links: PMID-41068567
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@article {pmid41068567,
year = {2025},
author = {Mondal, P and Mallick, B and Haldar, T and Ramesh, A and Sarbajna, A and Koley, H and Das, S},
title = {Utilizing the effectiveness of phage cocktail to combat Shigella and Salmonella infections and their polymicrobial biofilm control activity.},
journal = {BMC microbiology},
volume = {25},
number = {1},
pages = {649},
pmid = {41068567},
issn = {1471-2180},
mesh = {*Biofilms/growth & development ; Humans ; *Bacteriophages/physiology/isolation & purification ; *Salmonella Infections/therapy/microbiology ; *Salmonella/virology/physiology ; *Dysentery, Bacillary/therapy/microbiology ; *Shigella sonnei/virology/physiology ; Animals ; Phage Therapy ; *Shigella/virology/physiology ; Coinfection/therapy/microbiology ; Anti-Bacterial Agents/pharmacology ; },
abstract = {BACKGROUND: Shigella and Salmonella are major foodborne and waterborne pathogens responsible for acute gastrointestinal infections and significant global morbidity and mortality. Both species are capable of forming bacterial biofilms in the food processing industry, a key survival mechanism that significantly reduces the effectiveness of antibacterial drugs. The global rise in antimicrobial resistance (AMR) necessitates the urgent development of new strategies. Bacteriophages, particularly phage cocktails, provide a potential alternative because of their host specificity and ability to degrade biofilms.
RESULTS: In this study, a new bacteriophage, Sspk23, infecting Shigella sonnei, was isolated from lake water and biologically characterized to assess its lytic activity and stability under varying conditions. Furthermore, this study investigates the effectiveness of a phage cocktail, including a newly isolated Sspk23 and two previously identified phages, Sfk20 and STWB21, against Shigella and Salmonella infections with a focus on its ability to combat single and polymicrobial infections. The biofilm removal potential of the phage cocktail was observed using Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM), and also quantitatively assessed in a microtiter plate. Cytotoxicity tests were conducted on human adherent epithelial cell line and macrophage cell line to confirm the safety of the phage and phage cocktail for therapeutic use.
CONCLUSIONS: The findings demonstrate the possibility of a phage cocktail as a substitute for conventional antibiotics in controlling Shigella and Salmonella infections. Additionally, their capacity to destroy biofilms indicates potential applications in clinical therapies, environmental remediation, and food safety. Future studies will be focused on phage-antibiotic synergy optimization and in vivo validation to combat multidrug-resistant (MDR) bacteria.},
}
MeSH Terms:
show MeSH Terms
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*Biofilms/growth & development
Humans
*Bacteriophages/physiology/isolation & purification
*Salmonella Infections/therapy/microbiology
*Salmonella/virology/physiology
*Dysentery, Bacillary/therapy/microbiology
*Shigella sonnei/virology/physiology
Animals
Phage Therapy
*Shigella/virology/physiology
Coinfection/therapy/microbiology
Anti-Bacterial Agents/pharmacology
RevDate: 2025-10-09
CmpDate: 2025-10-09
Amplified copper ion interference and immunomodulation using self-thermophoretic nanomotors to treat refractory implant-associated biofilm infections.
Nature communications, 16(1):9009.
Orthopedic implant-associated biofilm infections (IABIs) are refractory to elimination because of the dense biofilm formation and local immunosuppressive microenvironment. Herein, we propose a copper-based therapeutic strategy to treat IABIs. Initially, the Janus bisphere nanostructure is fabricated using mesoporous silicon nanoparticle (MSN) with gold nanoparticle. Subsequently, copper peroxide (CP) nanodots are encapsulated within the MSN to form the final nanomotor Motor@CP. Our Motor@CP exhibits remarkable autonomous movement through near-infrared (NIR)-propelled self-thermophoretic propulsion, effectively penetrating dense biofilms and delivering CP. Notably, the acidic microenvironment facilitates CP decomposition into copper(II) and hydrogen peroxide. This process further generates hydroxyl radicals (•OH), extensively destroying biofilm integrity and enhancing intracellular uptake of copper ions that trigger bacterial cuproptosis-like death. Furthermore, Motor@CP markedly reprograms infiltrating macrophages toward pro-inflammatory phenotypes, thereby promoting an antimicrobial immune response. Overall, this presents a promising approach that leverages amplified copper ion interference and macrophage reprogramming to combat refractory orthopedic IABIs.
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@article {pmid41068088,
year = {2025},
author = {He, L and Pan, Q and Li, M and Wang, Z and Wang, L and Zhang, C and Wang, ZH and Shi, J and Li, D},
title = {Amplified copper ion interference and immunomodulation using self-thermophoretic nanomotors to treat refractory implant-associated biofilm infections.},
journal = {Nature communications},
volume = {16},
number = {1},
pages = {9009},
pmid = {41068088},
issn = {2041-1723},
support = {82102588//National Natural Science Foundation of China (National Science Foundation of China)/ ; 82102936//National Natural Science Foundation of China (National Science Foundation of China)/ ; 232300421050 and 242301420068//Natural Science Foundation of Henan Province (Henan Province Natural Science Foundation)/ ; 2023M743232//China Postdoctoral Science Foundation/ ; },
mesh = {*Copper/chemistry/pharmacology ; *Biofilms/drug effects/growth & development ; Animals ; Mice ; Macrophages/drug effects/immunology ; *Immunomodulation/drug effects ; Gold/chemistry ; Metal Nanoparticles/chemistry ; Humans ; *Prosthesis-Related Infections/drug therapy/microbiology/immunology ; Anti-Bacterial Agents/pharmacology ; Silicon/chemistry ; RAW 264.7 Cells ; Staphylococcus aureus/drug effects ; },
abstract = {Orthopedic implant-associated biofilm infections (IABIs) are refractory to elimination because of the dense biofilm formation and local immunosuppressive microenvironment. Herein, we propose a copper-based therapeutic strategy to treat IABIs. Initially, the Janus bisphere nanostructure is fabricated using mesoporous silicon nanoparticle (MSN) with gold nanoparticle. Subsequently, copper peroxide (CP) nanodots are encapsulated within the MSN to form the final nanomotor Motor@CP. Our Motor@CP exhibits remarkable autonomous movement through near-infrared (NIR)-propelled self-thermophoretic propulsion, effectively penetrating dense biofilms and delivering CP. Notably, the acidic microenvironment facilitates CP decomposition into copper(II) and hydrogen peroxide. This process further generates hydroxyl radicals (•OH), extensively destroying biofilm integrity and enhancing intracellular uptake of copper ions that trigger bacterial cuproptosis-like death. Furthermore, Motor@CP markedly reprograms infiltrating macrophages toward pro-inflammatory phenotypes, thereby promoting an antimicrobial immune response. Overall, this presents a promising approach that leverages amplified copper ion interference and macrophage reprogramming to combat refractory orthopedic IABIs.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Copper/chemistry/pharmacology
*Biofilms/drug effects/growth & development
Animals
Mice
Macrophages/drug effects/immunology
*Immunomodulation/drug effects
Gold/chemistry
Metal Nanoparticles/chemistry
Humans
*Prosthesis-Related Infections/drug therapy/microbiology/immunology
Anti-Bacterial Agents/pharmacology
Silicon/chemistry
RAW 264.7 Cells
Staphylococcus aureus/drug effects
RevDate: 2025-10-09
Marine biofilm microbial communities on deep-sea moorings as indicators of a changing environment.
Marine environmental research, 212:107598 pii:S0141-1136(25)00655-5 [Epub ahead of print].
Marine biofilms developed on buoys encasing Acoustic Doppler Current Profilers (ADCPs), deployed on deep-sea moorings for current measurements, were characterized for the first time along the continental slope of the west coast (Off Okha, Goa, Kollam) and east coast (Off Vishakhapatnam - Vizag) of India at a depth of ∼150 m over three years. The biofilm community structure and functions were elucidated using next-generation sequencing. High-throughput sequencing revealed spatio-temporal variations in the biofilm communities with site-specific microbial signatures and metabolic functions. Moreover, biofilms from the Bay of Bengal were significantly different from those in the Arabian Sea. Interestingly, Kollam biofilms were characterized by photoautotrophic carbon cycling and dominated by several cyanobacterial communities and purple non-sulfur bacterium, and is the first report of such taxa in marine biofilms at a depth of 150 m. Functional predictions indicated enhanced expression of stress-related pathways in the Vizag and Goa biofilms. Additionally, biofilms from all sites actively contributed to the degradation of carbon, nitrogen, sulfur, and hydrocarbons, highlighting their importance in marine biogeochemical processes. Notably, certain biofilm-forming genera were consistently present across all 3 years at specific sites, indicating ecological resilience and serving as bioindicators of long-term biofilm dynamics. Moreover, the presence of plastic-associated genera (Amphritea, Crocinitomix, Ulvibacter, and Oleiphilus) across several sites reflects the widespread occurrence of plastics in the surrounding marine environment. Emergence of Desulfobacterota post-lockdown in Okha biofilms suggests anthropogenic influence from increased petroleum activity and their role as markers of hydrocarbon contamination. The detection of sulfur-cycling and corrosion-associated taxa (Sulfurovum, Sedimenticola, Photobacterium, Tenacibaculum) suggests a persistent risk of microbially induced corrosion (MIC), potentially compromising the durability of oceanographic instruments/installations. These findings on deep ocean biofilm-forming bacteria not only provide valuable insights into the ecological and biogeochemical capabilities of microbes but also highlight their relevance as site-specific microbial signatures of marine pollution. This research can also aid in developing effective strategies to mitigate biofouling and bio-corrosion on oceanographic instruments.
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@article {pmid41067147,
year = {2025},
author = {Khandeparker, L and Hede, N and Desai, DV and D'Souza, R and Mapari, K},
title = {Marine biofilm microbial communities on deep-sea moorings as indicators of a changing environment.},
journal = {Marine environmental research},
volume = {212},
number = {},
pages = {107598},
doi = {10.1016/j.marenvres.2025.107598},
pmid = {41067147},
issn = {1879-0291},
abstract = {Marine biofilms developed on buoys encasing Acoustic Doppler Current Profilers (ADCPs), deployed on deep-sea moorings for current measurements, were characterized for the first time along the continental slope of the west coast (Off Okha, Goa, Kollam) and east coast (Off Vishakhapatnam - Vizag) of India at a depth of ∼150 m over three years. The biofilm community structure and functions were elucidated using next-generation sequencing. High-throughput sequencing revealed spatio-temporal variations in the biofilm communities with site-specific microbial signatures and metabolic functions. Moreover, biofilms from the Bay of Bengal were significantly different from those in the Arabian Sea. Interestingly, Kollam biofilms were characterized by photoautotrophic carbon cycling and dominated by several cyanobacterial communities and purple non-sulfur bacterium, and is the first report of such taxa in marine biofilms at a depth of 150 m. Functional predictions indicated enhanced expression of stress-related pathways in the Vizag and Goa biofilms. Additionally, biofilms from all sites actively contributed to the degradation of carbon, nitrogen, sulfur, and hydrocarbons, highlighting their importance in marine biogeochemical processes. Notably, certain biofilm-forming genera were consistently present across all 3 years at specific sites, indicating ecological resilience and serving as bioindicators of long-term biofilm dynamics. Moreover, the presence of plastic-associated genera (Amphritea, Crocinitomix, Ulvibacter, and Oleiphilus) across several sites reflects the widespread occurrence of plastics in the surrounding marine environment. Emergence of Desulfobacterota post-lockdown in Okha biofilms suggests anthropogenic influence from increased petroleum activity and their role as markers of hydrocarbon contamination. The detection of sulfur-cycling and corrosion-associated taxa (Sulfurovum, Sedimenticola, Photobacterium, Tenacibaculum) suggests a persistent risk of microbially induced corrosion (MIC), potentially compromising the durability of oceanographic instruments/installations. These findings on deep ocean biofilm-forming bacteria not only provide valuable insights into the ecological and biogeochemical capabilities of microbes but also highlight their relevance as site-specific microbial signatures of marine pollution. This research can also aid in developing effective strategies to mitigate biofouling and bio-corrosion on oceanographic instruments.},
}
RevDate: 2025-10-09
Biofilm with a mechanically strengthened character via enhanced cross-links of soybean proteins with short-chain fatty acid-modified starch.
Food chemistry, 495(Pt 3):146579 pii:S0308-8146(25)03831-2 [Epub ahead of print].
In this study, starch modified with different chain-length of short-chain fatty acids (SCFA) were prepared, followed by their corresponding interaction with soy protein isolate (SPI) and tannic acid (TA) to achieve biofilms with various structural characteristics and functionality. Current results indicated crosslinking of three composites occurred via formation of covalent Schiff base bonds, followed by an increased tensile strength of the biofilm by 2 times compared with biofilm prepared from binary composites. Importantly, this was the first time to achieve a maximum tensile strength of the biofilm up to 8.09 MPa. Furthermore, co-existence of the three components increased the elongation at break of SPI biofilm from 117.25 % to 174.50 %, demonstrating the formation of a biofilm with a mechanically strengthened character. This study highlights a novel approach for preparation of biofilms with an enhanced mechanical property via an appropriate interaction among a longer-chain SCFA modified starch, SPI and TA.
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@article {pmid41067014,
year = {2025},
author = {Ke, S and Li, G and Wang, A and Wu, H and Yu, P and Ning, M and Strappe, P and Wang, B and Blanchard, C and Zhou, Z and Zhao, G},
title = {Biofilm with a mechanically strengthened character via enhanced cross-links of soybean proteins with short-chain fatty acid-modified starch.},
journal = {Food chemistry},
volume = {495},
number = {Pt 3},
pages = {146579},
doi = {10.1016/j.foodchem.2025.146579},
pmid = {41067014},
issn = {1873-7072},
abstract = {In this study, starch modified with different chain-length of short-chain fatty acids (SCFA) were prepared, followed by their corresponding interaction with soy protein isolate (SPI) and tannic acid (TA) to achieve biofilms with various structural characteristics and functionality. Current results indicated crosslinking of three composites occurred via formation of covalent Schiff base bonds, followed by an increased tensile strength of the biofilm by 2 times compared with biofilm prepared from binary composites. Importantly, this was the first time to achieve a maximum tensile strength of the biofilm up to 8.09 MPa. Furthermore, co-existence of the three components increased the elongation at break of SPI biofilm from 117.25 % to 174.50 %, demonstrating the formation of a biofilm with a mechanically strengthened character. This study highlights a novel approach for preparation of biofilms with an enhanced mechanical property via an appropriate interaction among a longer-chain SCFA modified starch, SPI and TA.},
}
RevDate: 2025-10-09
Removal of environment relevant bisphenol A concentration from the contaminated waters using freshwater pond grown microalgae biofilm.
The Science of the total environment, 1003:180670 pii:S0048-9697(25)02310-1 [Epub ahead of print].
Bisphenol A (BPA), even at environmentally relevant concentration, exerts toxic effects on aquatic organisms and it requires sustainable removal strategies. Microalgae immobilization in substrate is an emerging technology for bioremediation with less practical implacability due to the high production cost of microalgae. Hence in the present study, microalgae present in the freshwater pond was grown attached to the synthetic substrates for four weeks and utilized for bioremediation. The biofilm, predominantly composed of Merismopedia sp., Cymbella sp., Nitzschia sp., Oscillatoria sp., and Pediastrum sp. was used to treat water samples spiked with environmentally relevant BPA concentration (0.015 ppm; recorded from Ganga River water, India by our team). Higher BPA concentrations (0.15, 1.5 and 15 ppm) were also used to document the toxic effect of BPA on microalgae biofilm. Results showed that microalgae biofilm removed 52.78 ± 2.38 % of BPA from the water contains 0.015 ppm concentration with a low toxic effect on growth and viability of the microalgae. Among which, microalgae biofilm accumulated 33.3 % of added BPA via adsorption and absorption, a significant portion of BPA also been removed by photo degradation and other process of degradation. The conductivity of the water significantly influenced the BPA removal efficiency of microalgae biofilm. As BPA concentration increased, the removal efficiency declined and exert toxic effect on microalgae biofilm growth and viability. The 120 h BPA exposure reduced the microalgae abundance in all treatments. The species like Nitzschia sp., Fragillaria sp. and Merismopedia sp., showed maximum reduction and the Coelastrum sp., Amphora sp., Phormidium sp., Phacus sp., Gomphonema sp. and Scenedesmus sp. showed tolerance towards BPA exposure. These findings highlight the potential of pond grown microalgae biofilm as a practical and eco-friendly solution for removing BPA from contaminated water, particularly at environment relevant concentrations.
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@article {pmid41066943,
year = {2025},
author = {Vanniaraj, SK and Bera, S and Paul, S and Kundu, S and Jayaswal, R and Dutta, S and Das, BK},
title = {Removal of environment relevant bisphenol A concentration from the contaminated waters using freshwater pond grown microalgae biofilm.},
journal = {The Science of the total environment},
volume = {1003},
number = {},
pages = {180670},
doi = {10.1016/j.scitotenv.2025.180670},
pmid = {41066943},
issn = {1879-1026},
abstract = {Bisphenol A (BPA), even at environmentally relevant concentration, exerts toxic effects on aquatic organisms and it requires sustainable removal strategies. Microalgae immobilization in substrate is an emerging technology for bioremediation with less practical implacability due to the high production cost of microalgae. Hence in the present study, microalgae present in the freshwater pond was grown attached to the synthetic substrates for four weeks and utilized for bioremediation. The biofilm, predominantly composed of Merismopedia sp., Cymbella sp., Nitzschia sp., Oscillatoria sp., and Pediastrum sp. was used to treat water samples spiked with environmentally relevant BPA concentration (0.015 ppm; recorded from Ganga River water, India by our team). Higher BPA concentrations (0.15, 1.5 and 15 ppm) were also used to document the toxic effect of BPA on microalgae biofilm. Results showed that microalgae biofilm removed 52.78 ± 2.38 % of BPA from the water contains 0.015 ppm concentration with a low toxic effect on growth and viability of the microalgae. Among which, microalgae biofilm accumulated 33.3 % of added BPA via adsorption and absorption, a significant portion of BPA also been removed by photo degradation and other process of degradation. The conductivity of the water significantly influenced the BPA removal efficiency of microalgae biofilm. As BPA concentration increased, the removal efficiency declined and exert toxic effect on microalgae biofilm growth and viability. The 120 h BPA exposure reduced the microalgae abundance in all treatments. The species like Nitzschia sp., Fragillaria sp. and Merismopedia sp., showed maximum reduction and the Coelastrum sp., Amphora sp., Phormidium sp., Phacus sp., Gomphonema sp. and Scenedesmus sp. showed tolerance towards BPA exposure. These findings highlight the potential of pond grown microalgae biofilm as a practical and eco-friendly solution for removing BPA from contaminated water, particularly at environment relevant concentrations.},
}
RevDate: 2025-10-09
CmpDate: 2025-10-09
Bacteriophage as an anti-biofilm agent against Pseudomonas aeruginosa from wound infection.
PloS one, 20(10):e0334139 pii:PONE-D-25-32686.
Pseudomonas aeruginosa, an opportunistic pathogen associated with wound infections, resists many commonly available antibiotics. Its ability to form biofilm provides an additional trait to evade antibiotics. Biofilm-associated infections are difficult to treat, raising the need for alternative strategies. Thus, this research aimed to investigate the potential of bacteriophage to disrupt the biofilm produced by P. aeruginosa isolated from wound infections. Wound samples were collected aseptically, processed for the isolation of P. aeruginosa, and identified by standard microbiological methods. Antimicrobial susceptibility was determined by the Kirby-Bauer disc diffusion method. Bacteriophages were isolated using the double-layer agar method. Phenotypic assessment of biofilm formation by the isolates and its reduction by phages was conducted by the tissue culture plate assay. Out of 647 wound samples processed, 96 P. aeruginosa were isolated. Piperacillin/tazobactam was the most effective antibiotic, while doxycycline was the least effective. Among the total isolates, 86 (89.6%) were multidrug-resistant (MDR) and 69 (71.9%) were biofilm producers. Three different phages isolated from sewage demonstrated a high specificity to P. aeruginosa. Of these, phage vB_PaeP_PS2 lysed the highest number of isolates (22.9%), including 17 MDR and 21 biofilm-producing isolates. The biofilm reduction assay demonstrated that phage treatment significantly reduced biofilm formation, with vB_PaeP_PS2 achieving a 58% reduction after 6 h of treatment. In conclusion, this study highlights the high prevalence of biofilm-producing MDR P. aeruginosa in wound infections and, for the first time in Nepal, demonstrates the potential of locally isolated phages to lyse biofilm-forming MDR isolates and disrupt their biofilms.
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@article {pmid41066428,
year = {2025},
author = {Shrestha, P and Tandukar, S and Shrestha, M and Shrestha, S and Subedee, A and Shakya, J and Tuladhar, R},
title = {Bacteriophage as an anti-biofilm agent against Pseudomonas aeruginosa from wound infection.},
journal = {PloS one},
volume = {20},
number = {10},
pages = {e0334139},
doi = {10.1371/journal.pone.0334139},
pmid = {41066428},
issn = {1932-6203},
mesh = {*Biofilms/drug effects/growth & development ; *Pseudomonas aeruginosa/virology/physiology/drug effects/isolation & purification ; *Wound Infection/microbiology/therapy ; *Pseudomonas Infections/microbiology/therapy ; *Bacteriophages/physiology ; Humans ; Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; Drug Resistance, Multiple, Bacterial ; Phage Therapy ; *Pseudomonas Phages/physiology ; },
abstract = {Pseudomonas aeruginosa, an opportunistic pathogen associated with wound infections, resists many commonly available antibiotics. Its ability to form biofilm provides an additional trait to evade antibiotics. Biofilm-associated infections are difficult to treat, raising the need for alternative strategies. Thus, this research aimed to investigate the potential of bacteriophage to disrupt the biofilm produced by P. aeruginosa isolated from wound infections. Wound samples were collected aseptically, processed for the isolation of P. aeruginosa, and identified by standard microbiological methods. Antimicrobial susceptibility was determined by the Kirby-Bauer disc diffusion method. Bacteriophages were isolated using the double-layer agar method. Phenotypic assessment of biofilm formation by the isolates and its reduction by phages was conducted by the tissue culture plate assay. Out of 647 wound samples processed, 96 P. aeruginosa were isolated. Piperacillin/tazobactam was the most effective antibiotic, while doxycycline was the least effective. Among the total isolates, 86 (89.6%) were multidrug-resistant (MDR) and 69 (71.9%) were biofilm producers. Three different phages isolated from sewage demonstrated a high specificity to P. aeruginosa. Of these, phage vB_PaeP_PS2 lysed the highest number of isolates (22.9%), including 17 MDR and 21 biofilm-producing isolates. The biofilm reduction assay demonstrated that phage treatment significantly reduced biofilm formation, with vB_PaeP_PS2 achieving a 58% reduction after 6 h of treatment. In conclusion, this study highlights the high prevalence of biofilm-producing MDR P. aeruginosa in wound infections and, for the first time in Nepal, demonstrates the potential of locally isolated phages to lyse biofilm-forming MDR isolates and disrupt their biofilms.},
}
MeSH Terms:
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*Biofilms/drug effects/growth & development
*Pseudomonas aeruginosa/virology/physiology/drug effects/isolation & purification
*Wound Infection/microbiology/therapy
*Pseudomonas Infections/microbiology/therapy
*Bacteriophages/physiology
Humans
Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests
Drug Resistance, Multiple, Bacterial
Phage Therapy
*Pseudomonas Phages/physiology
RevDate: 2025-10-09
CmpDate: 2025-10-09
Proteomic and Phosphoproteomic Landscapes of Azole Resistance in Aspergillus fumigatus Biofilm Exposed to Voriconazole.
Mycopathologia, 190(6):100.
Aspergillus fumigatus, an opportunistic and allergenic pathogenic fungus, is responsible for a range of clinical disorders in humans, including invasive aspergillosis (IA), which can lead to severe infections in immunocompromised individuals. Unfortunately, the emergence of azole resistance has become a significant challenge in combating IA, necessitating further investigations into the underlying mechanisms of resistance. In this study, we conducted an integrated proteomic and phosphoproteomic analysis of biofilm proteins from both azole-resistant and wildtype strains of A. fumigatus under voriconazole pressure. Our proteomic analysis identified 148 upregulated and 146 downregulated proteins in the azole-resistant strains, while phosphoproteomic analysis revealed 316 upregulated phosphopeptides and 109 downregulated phosphopeptides, suggesting extensive phosphorylation modifications associated with azole resistance. Upon excluding the impact of protein changes, we identified 133 proteins with differential expression solely at the phosphorylation level, comprising 104 upregulated and 29 downregulated proteins. Functional annotation and analysis highlighted the significance of these differentially expressed phosphoproteins in cell wall integrity, filamentous growth, and high-osmolarity stress response, with 33 MAPK pathway-associated proteins displaying phosphopeptide level regulation. These findings provide valuable insights into the mechanisms behind azole resistance in A. fumigatus and offer potential new drug targets for combating this pathogenic fungus in humans.
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@article {pmid41065963,
year = {2025},
author = {Hong, P and Zheng, N and Wei, T and Zhang, Y and Zhu, F and Chen, Y and She, X and Liu, W and Liu, M},
title = {Proteomic and Phosphoproteomic Landscapes of Azole Resistance in Aspergillus fumigatus Biofilm Exposed to Voriconazole.},
journal = {Mycopathologia},
volume = {190},
number = {6},
pages = {100},
pmid = {41065963},
issn = {1573-0832},
support = {81501726//the National Natural Science Foundation of China/ ; 2019XK320077//the Fundamental Research Funds for the Central Universities/ ; BK20150069//the Natural Science Foundation of Jiangsu Province/ ; 2021-I2M-1-039//the CAMS Innovation Fund for Medical Sciences/ ; No. NPRC-32//the National Science and Technology Infrastructure of China/ ; },
mesh = {*Aspergillus fumigatus/drug effects/physiology/chemistry/genetics ; *Voriconazole/pharmacology ; *Antifungal Agents/pharmacology ; *Biofilms/drug effects/growth & development ; *Drug Resistance, Fungal ; Proteomics ; *Proteome/analysis ; *Azoles/pharmacology ; *Fungal Proteins/analysis ; *Phosphoproteins/analysis ; Humans ; },
abstract = {Aspergillus fumigatus, an opportunistic and allergenic pathogenic fungus, is responsible for a range of clinical disorders in humans, including invasive aspergillosis (IA), which can lead to severe infections in immunocompromised individuals. Unfortunately, the emergence of azole resistance has become a significant challenge in combating IA, necessitating further investigations into the underlying mechanisms of resistance. In this study, we conducted an integrated proteomic and phosphoproteomic analysis of biofilm proteins from both azole-resistant and wildtype strains of A. fumigatus under voriconazole pressure. Our proteomic analysis identified 148 upregulated and 146 downregulated proteins in the azole-resistant strains, while phosphoproteomic analysis revealed 316 upregulated phosphopeptides and 109 downregulated phosphopeptides, suggesting extensive phosphorylation modifications associated with azole resistance. Upon excluding the impact of protein changes, we identified 133 proteins with differential expression solely at the phosphorylation level, comprising 104 upregulated and 29 downregulated proteins. Functional annotation and analysis highlighted the significance of these differentially expressed phosphoproteins in cell wall integrity, filamentous growth, and high-osmolarity stress response, with 33 MAPK pathway-associated proteins displaying phosphopeptide level regulation. These findings provide valuable insights into the mechanisms behind azole resistance in A. fumigatus and offer potential new drug targets for combating this pathogenic fungus in humans.},
}
MeSH Terms:
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*Aspergillus fumigatus/drug effects/physiology/chemistry/genetics
*Voriconazole/pharmacology
*Antifungal Agents/pharmacology
*Biofilms/drug effects/growth & development
*Drug Resistance, Fungal
Proteomics
*Proteome/analysis
*Azoles/pharmacology
*Fungal Proteins/analysis
*Phosphoproteins/analysis
Humans
RevDate: 2025-10-09
Vulvovaginal candidiasis in rural pregnant populations from Uttar Pradesh, India: species shift, biofilm formation, and resistance trends.
Naunyn-Schmiedeberg's archives of pharmacology [Epub ahead of print].
Vulvovaginal candidiasis (VVC) is a common infection in pregnancy, with increasing concern over the emergence of non-albicans Candida (NAC) species and antifungal resistance, particularly in biofilm-forming strains. A total of 913 pregnant women with clinically suspected VVC were evaluated. Demographic and clinical data were collected, and specimens were processed using KOH mount and fungal culture. Isolates were identified to the species level using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), assessed for biofilm formation by the tissue culture plate (TCP) method, and tested for antifungal susceptibility by Kirby-Bauer disk diffusion method. The highest prevalence was observed in women aged 23-28 years (35.7%) and those from rural areas (61.7%). Illiteracy (54.5%), third-trimester pregnancy (43.7%), and multigravida status (57.6%) were predominant. Mixed symptoms, especially the triad of itching, burning, and discharge (27.2%), were most common. Culture had a higher sensitivity (83.6%) than KOH microscopy (77.2%). Candida albicans was the predominant species (59.8%), followed by Candida glabrata (15.3%) and Candida tropicalis (9.8%). NAC species accounted for 40.2% of isolates. Biofilm production was highest in C. albicans (85.1%), C. tropicalis (74.7%), and C. glabrata (59.8%). Antifungal resistance was significantly higher in biofilm producers, particularly to azoles: ketoconazole (83.3% vs. 16.7%, p < 0.001) and fluconazole (81.5% vs. 18.5%, p < 0.001). Amphotericin B also showed reduced efficacy in biofilm producers (66.7% vs. 33.3%, p < 0.05). This study reports a high prevalence of VVC (83.6%) in pregnant women, predominantly in rural, less-educated, and multigravida groups. C. albicans remained the leading pathogen, but the notable presence of non-albicans species reflects a shifting epidemiology. Biofilm formation, especially by C. albicans, C. tropicalis, and C. glabrata, correlated with marked azole resistance. Routine species-level identification, biofilm evaluation, and antifungal susceptibility testing are essential for optimizing treatment in pregnancy.
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@article {pmid41065833,
year = {2025},
author = {Moursi, SA and Saxena, R and Haider, F and Khan, MS and Saleem, M and Ahmad, I and Ahmad, N},
title = {Vulvovaginal candidiasis in rural pregnant populations from Uttar Pradesh, India: species shift, biofilm formation, and resistance trends.},
journal = {Naunyn-Schmiedeberg's archives of pharmacology},
volume = {},
number = {},
pages = {},
pmid = {41065833},
issn = {1432-1912},
abstract = {Vulvovaginal candidiasis (VVC) is a common infection in pregnancy, with increasing concern over the emergence of non-albicans Candida (NAC) species and antifungal resistance, particularly in biofilm-forming strains. A total of 913 pregnant women with clinically suspected VVC were evaluated. Demographic and clinical data were collected, and specimens were processed using KOH mount and fungal culture. Isolates were identified to the species level using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), assessed for biofilm formation by the tissue culture plate (TCP) method, and tested for antifungal susceptibility by Kirby-Bauer disk diffusion method. The highest prevalence was observed in women aged 23-28 years (35.7%) and those from rural areas (61.7%). Illiteracy (54.5%), third-trimester pregnancy (43.7%), and multigravida status (57.6%) were predominant. Mixed symptoms, especially the triad of itching, burning, and discharge (27.2%), were most common. Culture had a higher sensitivity (83.6%) than KOH microscopy (77.2%). Candida albicans was the predominant species (59.8%), followed by Candida glabrata (15.3%) and Candida tropicalis (9.8%). NAC species accounted for 40.2% of isolates. Biofilm production was highest in C. albicans (85.1%), C. tropicalis (74.7%), and C. glabrata (59.8%). Antifungal resistance was significantly higher in biofilm producers, particularly to azoles: ketoconazole (83.3% vs. 16.7%, p < 0.001) and fluconazole (81.5% vs. 18.5%, p < 0.001). Amphotericin B also showed reduced efficacy in biofilm producers (66.7% vs. 33.3%, p < 0.05). This study reports a high prevalence of VVC (83.6%) in pregnant women, predominantly in rural, less-educated, and multigravida groups. C. albicans remained the leading pathogen, but the notable presence of non-albicans species reflects a shifting epidemiology. Biofilm formation, especially by C. albicans, C. tropicalis, and C. glabrata, correlated with marked azole resistance. Routine species-level identification, biofilm evaluation, and antifungal susceptibility testing are essential for optimizing treatment in pregnancy.},
}
RevDate: 2025-10-09
CmpDate: 2025-10-09
Exploring cinnamic acid's function in reducing the quorum sensing and biofilm formation in Pseudomonas aeruginosa: in vitro and in silico investigations.
Archives of microbiology, 207(11):292.
Antimicrobial resistance (AMR) has become serious global threat to the public health which is estimated to be responsible for over one million annual deaths. AMR occurs when microbes develop defence mechanism against the antibiotics. Pseudomonas aeruginosa is an opportunistic pathogen which is known to cause many infections, and it has developed resistance to multiple antibiotic classes. The continuous exposure of antibiotics imposes the risk of AMR development. In this case, targeting quorum sensing (QS) and biofilms becomes more reasonable. This study assessed the effect of cinnamic acid (CA) on biofilm formation and QS-regulated virulence factors in P. aeruginosa PAO1. Preliminary assays showed that CA inhibited violacein production by 63.88 ± 2.44% in C. violaceum 12472. The virulence factors of P. aeruginosa PAO1, namely pyocyanin production, pyoverdin production, elastase, exoprotease, rhamnolipid production, and swimming motility was reduced by 72.55 ± 4.05%, 58.90 ± 3.15%, 47.50 ± 5.55%, 65.86 ± 2.65%, 51.37 ± 2.43%, and 85.61 ± 2.52%, respectively. CA inhibited biofilm by > 65% and also reduced the bacterial colonization and aggregation. Molecular docking revealed that CA binds at the active site of target proteins of P. aeruginosa such as LasA, LasI, LasR, and PqsR. Molecular simulations validated the stability of complexes of these proteins with CA. The interaction of CA to these proteins was mainly favoured by van der Waals and electrostatic forces. This study shows CA's potential to interfere with QS and biofilm in P. aeruginosa, indicating its potential as a candidate molecule for developing new treatments aimed at targeting biofilm-associated infections.
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@article {pmid41065783,
year = {2025},
author = {Dai, H and Qin, C and Gao, Y},
title = {Exploring cinnamic acid's function in reducing the quorum sensing and biofilm formation in Pseudomonas aeruginosa: in vitro and in silico investigations.},
journal = {Archives of microbiology},
volume = {207},
number = {11},
pages = {292},
pmid = {41065783},
issn = {1432-072X},
mesh = {*Quorum Sensing/drug effects ; *Biofilms/drug effects/growth & development ; *Pseudomonas aeruginosa/drug effects/physiology/genetics ; *Cinnamates/pharmacology ; Virulence Factors/metabolism ; Molecular Docking Simulation ; Bacterial Proteins/metabolism/chemistry/genetics ; *Anti-Bacterial Agents/pharmacology ; Chromobacterium/drug effects ; Indoles/metabolism ; Pyocyanine/metabolism ; Glycolipids ; },
abstract = {Antimicrobial resistance (AMR) has become serious global threat to the public health which is estimated to be responsible for over one million annual deaths. AMR occurs when microbes develop defence mechanism against the antibiotics. Pseudomonas aeruginosa is an opportunistic pathogen which is known to cause many infections, and it has developed resistance to multiple antibiotic classes. The continuous exposure of antibiotics imposes the risk of AMR development. In this case, targeting quorum sensing (QS) and biofilms becomes more reasonable. This study assessed the effect of cinnamic acid (CA) on biofilm formation and QS-regulated virulence factors in P. aeruginosa PAO1. Preliminary assays showed that CA inhibited violacein production by 63.88 ± 2.44% in C. violaceum 12472. The virulence factors of P. aeruginosa PAO1, namely pyocyanin production, pyoverdin production, elastase, exoprotease, rhamnolipid production, and swimming motility was reduced by 72.55 ± 4.05%, 58.90 ± 3.15%, 47.50 ± 5.55%, 65.86 ± 2.65%, 51.37 ± 2.43%, and 85.61 ± 2.52%, respectively. CA inhibited biofilm by > 65% and also reduced the bacterial colonization and aggregation. Molecular docking revealed that CA binds at the active site of target proteins of P. aeruginosa such as LasA, LasI, LasR, and PqsR. Molecular simulations validated the stability of complexes of these proteins with CA. The interaction of CA to these proteins was mainly favoured by van der Waals and electrostatic forces. This study shows CA's potential to interfere with QS and biofilm in P. aeruginosa, indicating its potential as a candidate molecule for developing new treatments aimed at targeting biofilm-associated infections.},
}
MeSH Terms:
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*Quorum Sensing/drug effects
*Biofilms/drug effects/growth & development
*Pseudomonas aeruginosa/drug effects/physiology/genetics
*Cinnamates/pharmacology
Virulence Factors/metabolism
Molecular Docking Simulation
Bacterial Proteins/metabolism/chemistry/genetics
*Anti-Bacterial Agents/pharmacology
Chromobacterium/drug effects
Indoles/metabolism
Pyocyanine/metabolism
Glycolipids
RevDate: 2025-10-09
CmpDate: 2025-10-09
Phytochemical inhibition of quorum sensing and biofilm formation by Paederia foetida Linn. against multidrug-resistant Acinetobacter baumannii: An integrated in vitro and in silico investigation.
Veterinary world, 18(8):2181-2193.
BACKGROUND AND AIM: Acinetobacter baumannii is a multidrug-resistant (MDR) pathogen notorious for its biofilm formation and persistence in clinical and veterinary settings. Its resistance is exacerbated by quorum sensing (QS) pathways that regulate virulence and biofilm maturation. Disrupting QS and biofilm integrity using plant-derived compounds presents a promising alternative to traditional antibiotics. This study aimed to evaluate the antibiofilm and anti-QS potential of Paederia foetida Linn. ethanolic extract against A. baumannii, integrating gas chromatography-mass spectrometry (GC-MS) profiling, molecular docking, and in vitro assays.
MATERIALS AND METHODS: Leaves of P. foetida were extracted with ethanol and analyzed by GC-MS to identify major bioactive constituents. Molecular docking was conducted against five QS and biofilm-associated A. baumannii proteins (AF-A0A7S8WE28-F1-v4, AF-A0A059ZL64-F1-v4, AF-Q2VSW6-F1-v4, AF-A0A2P1B9S4-F1-v4, and AF-A0A5P9VY74-F1-v4). Absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles and drug-likeness of key compounds were assessed in silico. Antimicrobial activity was determined by broth microdilution (minimum inhibitory concentration [MIC]/minimum bactericidal concentration [MBC]), and biofilm inhibition was evaluated through crystal violet microtiter assays. Morphological damage was examined using field emission scanning electron microscopy (FE-SEM).
RESULTS: GC-MS identified 30 phytoconstituents, with 5-hydroxymethyl-2-furaldehyde, 4H-pyran-4-one derivative, and eugenol as predominant compounds. Eugenol exhibited the highest binding affinity, particularly with AbaR (-6.3 kcal/mol). The extract showed significant antimicrobial activity (MIC = 7.81 mg/mL; MBC = 31.25 mg/mL) and dose-dependent inhibition of biofilm biomass (p < 0.001). FE-SEM imaging confirmed dose-responsive membrane damage and disruption of the biofilm. ADMET predictions revealed favorable oral bioavailability and low toxicity for selected compounds.
CONCLUSION: P. foetida extract exhibits potent antibacterial, anti-QS, and antibiofilm activity against MDR A. baumannii, supported by its phytochemical diversity, favorable pharmacokinetics, and strong protein-ligand interactions. These findings suggest its promise as a plant-derived therapeutic aligned with the One Health framework to combat antimicrobial resistance in both human and veterinary medicine.
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@article {pmid41064837,
year = {2025},
author = {Santajit, S and Thavorasak, T and Horpet, D and Kong-Ngoen, T and Permpoon, U and Kim, CY and Nam, TG and Indrawattana, N},
title = {Phytochemical inhibition of quorum sensing and biofilm formation by Paederia foetida Linn. against multidrug-resistant Acinetobacter baumannii: An integrated in vitro and in silico investigation.},
journal = {Veterinary world},
volume = {18},
number = {8},
pages = {2181-2193},
pmid = {41064837},
issn = {0972-8988},
abstract = {BACKGROUND AND AIM: Acinetobacter baumannii is a multidrug-resistant (MDR) pathogen notorious for its biofilm formation and persistence in clinical and veterinary settings. Its resistance is exacerbated by quorum sensing (QS) pathways that regulate virulence and biofilm maturation. Disrupting QS and biofilm integrity using plant-derived compounds presents a promising alternative to traditional antibiotics. This study aimed to evaluate the antibiofilm and anti-QS potential of Paederia foetida Linn. ethanolic extract against A. baumannii, integrating gas chromatography-mass spectrometry (GC-MS) profiling, molecular docking, and in vitro assays.
MATERIALS AND METHODS: Leaves of P. foetida were extracted with ethanol and analyzed by GC-MS to identify major bioactive constituents. Molecular docking was conducted against five QS and biofilm-associated A. baumannii proteins (AF-A0A7S8WE28-F1-v4, AF-A0A059ZL64-F1-v4, AF-Q2VSW6-F1-v4, AF-A0A2P1B9S4-F1-v4, and AF-A0A5P9VY74-F1-v4). Absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles and drug-likeness of key compounds were assessed in silico. Antimicrobial activity was determined by broth microdilution (minimum inhibitory concentration [MIC]/minimum bactericidal concentration [MBC]), and biofilm inhibition was evaluated through crystal violet microtiter assays. Morphological damage was examined using field emission scanning electron microscopy (FE-SEM).
RESULTS: GC-MS identified 30 phytoconstituents, with 5-hydroxymethyl-2-furaldehyde, 4H-pyran-4-one derivative, and eugenol as predominant compounds. Eugenol exhibited the highest binding affinity, particularly with AbaR (-6.3 kcal/mol). The extract showed significant antimicrobial activity (MIC = 7.81 mg/mL; MBC = 31.25 mg/mL) and dose-dependent inhibition of biofilm biomass (p < 0.001). FE-SEM imaging confirmed dose-responsive membrane damage and disruption of the biofilm. ADMET predictions revealed favorable oral bioavailability and low toxicity for selected compounds.
CONCLUSION: P. foetida extract exhibits potent antibacterial, anti-QS, and antibiofilm activity against MDR A. baumannii, supported by its phytochemical diversity, favorable pharmacokinetics, and strong protein-ligand interactions. These findings suggest its promise as a plant-derived therapeutic aligned with the One Health framework to combat antimicrobial resistance in both human and veterinary medicine.},
}
RevDate: 2025-10-09
CmpDate: 2025-10-09
Biofilm-mediated antimicrobial resistance among meat-borne pathogens in Al-Suwaria, Iraq: A cross-species investigation from retail markets.
Veterinary world, 18(8):2487-2498.
BACKGROUND AND AIM: Biofilms formed by foodborne pathogens represent a significant threat to public health by enhancing microbial survival and facilitating antimicrobial resistance (AMR). In Iraq, data on the biofilm-producing potential of key meat-borne pathogens remain scarce, particularly for fastidious organisms such as Campylobacter, Arcobacter, and Salmonella serovars. This study investigated the prevalence and intensity of biofilm formation in selected meat-borne bacterial isolates and examined their correlation with phenotypic AMR, focusing on moderate to strong biofilm producers.
MATERIALS AND METHODS: A total of 44 bacterial isolates - including Staphylococcus aureus (methicillin-resistant S. aureus [MRSA]), Arcobacter butzleri, Arcobacter cryaerophilus, Campylobacter jejuni, Campylobacter coli, Salmonella enterica serovars Enteritidis, and Salmonella Typhimurium - were recovered from retail meat samples collected between 2018 and 2023 in Wasit, Iraq. Biofilm-forming ability was quantified using microtiter plate assays and interpreted per Stepanovic's criteria. Antimicrobial susceptibility was assessed through the Kirby-Bauer disk diffusion method, with resistance patterns statistically analyzed for associations with biofilm strength.
RESULTS: Among all isolates, 25% were strong and 40.91% moderate biofilm producers. Salmonella serotypes showed the highest biofilm strength (100%), followed by C. jejuni (75%) and MRSA (57.14%). A significant correlation (p ≤ 0.05) was observed between biofilm production and resistance to vancomycin, ofloxacin, gentamicin, enrofloxacin, and cefoxitin. Gram-negative isolates with strong to moderate biofilm capacity exhibited resistance rates ranging from 61.90% to 95.24%, while Gram-positive MRSA showed higher resistance to fluoroquinolones and aminoglycosides.
CONCLUSION: Biofilm production significantly contributes to increase AMR among meat-borne pathogens, compromising food safety and treatment efficacy. Enhanced surveillance, targeted biofilm control strategies, and molecular studies are crucial to mitigate the rising threat of biofilm-associated AMR in the food chain.
Additional Links: PMID-41064834
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@article {pmid41064834,
year = {2025},
author = {Kanaan, MHG and Khalil, ZK and Tarek, AM},
title = {Biofilm-mediated antimicrobial resistance among meat-borne pathogens in Al-Suwaria, Iraq: A cross-species investigation from retail markets.},
journal = {Veterinary world},
volume = {18},
number = {8},
pages = {2487-2498},
pmid = {41064834},
issn = {0972-8988},
abstract = {BACKGROUND AND AIM: Biofilms formed by foodborne pathogens represent a significant threat to public health by enhancing microbial survival and facilitating antimicrobial resistance (AMR). In Iraq, data on the biofilm-producing potential of key meat-borne pathogens remain scarce, particularly for fastidious organisms such as Campylobacter, Arcobacter, and Salmonella serovars. This study investigated the prevalence and intensity of biofilm formation in selected meat-borne bacterial isolates and examined their correlation with phenotypic AMR, focusing on moderate to strong biofilm producers.
MATERIALS AND METHODS: A total of 44 bacterial isolates - including Staphylococcus aureus (methicillin-resistant S. aureus [MRSA]), Arcobacter butzleri, Arcobacter cryaerophilus, Campylobacter jejuni, Campylobacter coli, Salmonella enterica serovars Enteritidis, and Salmonella Typhimurium - were recovered from retail meat samples collected between 2018 and 2023 in Wasit, Iraq. Biofilm-forming ability was quantified using microtiter plate assays and interpreted per Stepanovic's criteria. Antimicrobial susceptibility was assessed through the Kirby-Bauer disk diffusion method, with resistance patterns statistically analyzed for associations with biofilm strength.
RESULTS: Among all isolates, 25% were strong and 40.91% moderate biofilm producers. Salmonella serotypes showed the highest biofilm strength (100%), followed by C. jejuni (75%) and MRSA (57.14%). A significant correlation (p ≤ 0.05) was observed between biofilm production and resistance to vancomycin, ofloxacin, gentamicin, enrofloxacin, and cefoxitin. Gram-negative isolates with strong to moderate biofilm capacity exhibited resistance rates ranging from 61.90% to 95.24%, while Gram-positive MRSA showed higher resistance to fluoroquinolones and aminoglycosides.
CONCLUSION: Biofilm production significantly contributes to increase AMR among meat-borne pathogens, compromising food safety and treatment efficacy. Enhanced surveillance, targeted biofilm control strategies, and molecular studies are crucial to mitigate the rising threat of biofilm-associated AMR in the food chain.},
}
RevDate: 2025-10-09
CmpDate: 2025-10-09
β-tricalcium phosphate/calcium sulfate loaded with contezolid acefosamil (MRX-4) for antimicrobial potency, prevention and killing efficacy of MRSA biofilm.
Frontiers in pharmacology, 16:1657099.
OBJECTIVES: This study aimed to evaluate the antimicrobial potency and duration of contezolid acefosamil (MRX-4) combined with gentamicin against methicillin-resistant Staphylococcus aureus (MRSA) biofilms in vitro. We also compared its performance, when delivered via calcium sulfate (CS) and β-tricalcium phosphate/calcium sulfate (β-TCP/CS) carriers, with the conventional vancomycin + gentamicin regimen.
METHODS: Antibiotic-loaded beads containing MRX-4 + gentamicin (C + G) or vancomycin + gentamicin (V + G) were prepared using CS and β-TCP/CS carriers. Antimicrobial potency and release duration were assessed using a modified Kirby-Bauer zone of inhibition (ZOI) assay. MRSA biofilm prevention and eradication were evaluated through colony forming unit (CFU) counting and confocal laser scanning microscopy (CLSM).
RESULTS: C + G demonstrated prolonged antimicrobial activity, maintaining effective ZOIs for at least 40 days, whereas V + G lost activity by day 40 (P < 0.05). Both C + G and V + G significantly prevented biofilm formation and reduced CFUs by > 8 logs (P < 0.001), with no significant difference between carrier types. In biofilm eradication assays, both treatments reduced CFUs by 3-4 logs; however, C + G showed superior efficacy over V + G at day 3 (P < 0.01). CLSM confirmed substantial biofilm disruption and bacterial killing in C + G-treated groups.
CONCLUSION: MRX-4 combined with gentamicin, delivered via CS and β-TCP/CS carriers, exhibits superior and sustained local antimicrobial efficacy compared to vancomycin, particularly in eradicating MRSA biofilms.
Additional Links: PMID-41064445
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@article {pmid41064445,
year = {2025},
author = {Jiang, N and Zhang, X and Liu, ZX and Wan, HY and Huang, MZ and Lin, QR and Liu, GQ and Chen, P and Yu, B},
title = {β-tricalcium phosphate/calcium sulfate loaded with contezolid acefosamil (MRX-4) for antimicrobial potency, prevention and killing efficacy of MRSA biofilm.},
journal = {Frontiers in pharmacology},
volume = {16},
number = {},
pages = {1657099},
pmid = {41064445},
issn = {1663-9812},
abstract = {OBJECTIVES: This study aimed to evaluate the antimicrobial potency and duration of contezolid acefosamil (MRX-4) combined with gentamicin against methicillin-resistant Staphylococcus aureus (MRSA) biofilms in vitro. We also compared its performance, when delivered via calcium sulfate (CS) and β-tricalcium phosphate/calcium sulfate (β-TCP/CS) carriers, with the conventional vancomycin + gentamicin regimen.
METHODS: Antibiotic-loaded beads containing MRX-4 + gentamicin (C + G) or vancomycin + gentamicin (V + G) were prepared using CS and β-TCP/CS carriers. Antimicrobial potency and release duration were assessed using a modified Kirby-Bauer zone of inhibition (ZOI) assay. MRSA biofilm prevention and eradication were evaluated through colony forming unit (CFU) counting and confocal laser scanning microscopy (CLSM).
RESULTS: C + G demonstrated prolonged antimicrobial activity, maintaining effective ZOIs for at least 40 days, whereas V + G lost activity by day 40 (P < 0.05). Both C + G and V + G significantly prevented biofilm formation and reduced CFUs by > 8 logs (P < 0.001), with no significant difference between carrier types. In biofilm eradication assays, both treatments reduced CFUs by 3-4 logs; however, C + G showed superior efficacy over V + G at day 3 (P < 0.01). CLSM confirmed substantial biofilm disruption and bacterial killing in C + G-treated groups.
CONCLUSION: MRX-4 combined with gentamicin, delivered via CS and β-TCP/CS carriers, exhibits superior and sustained local antimicrobial efficacy compared to vancomycin, particularly in eradicating MRSA biofilms.},
}
RevDate: 2025-10-09
CmpDate: 2025-10-09
Antisense phosphorodiamidate morpholino oligomers retain activity in Burkholderia cepacia complex biofilm.
Frontiers in microbiology, 16:1660799.
BACKGROUND: Members of the Burkholderia cepacia complex (Bcc) are known to cause severe pulmonary infections in immunocompromised hosts, namely individuals with cystic fibrosis (CF) and chronic granulomatous disease (CGD). Due to innate antibiotic-resistant phenotypes and the formation of protective biofilms, Bcc bacteria are difficult to eradicate from colonized lungs using traditional antibiotics. An alternative therapeutic approach involves the use of antisense molecules, specifically peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs). Previously, we found that PPMOs targeting the acyl carrier protein (AcpP) can reduce the burden of planktonic Bcc bacteria.
METHODS: Antimicrobial activities of AcpP PPMOs were assessed against established biofilms produced by Bcc clinical isolates, in which viable cells, biomass, and metabolic activity were enumerated. Bactericidal effects were further evaluated by microscopy. Cytotoxicity of these molecules was tested in human pulmonary cell lines.
RESULTS: AcpP PPMO treatment resulted in over three-log reductions (p < 0.0001) in biofilm burden across five clinical isolates of Bcc that were tested. A dose-dependent effect was observed (5-40 μΜ). This effect was visualized using confocal and scanning electron microscopy. We further demonstrated that PPMOs associate with bacterial cells in a time-dependent fashion using a fluorescently labeled AcpP PPMO with B. cenocepacia K56-2 DsRed. Finally, alveolar cells retained viability with AcpP PPMOs at bactericidal dosages.
CONCLUSION: The Bcc biofilm setting is not a deterrent against PPMO delivery or antimicrobial activity. This is supported by the colocalization of AcpP PPMOs with cells, membrane destruction, loss of cell viability, and biomass reduction. Collectively, these data provide evidence that AcpP PPMOs are a promising therapeutic strategy in the treatment of Bcc infections.
Additional Links: PMID-41064251
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@article {pmid41064251,
year = {2025},
author = {Mendez, AR and Pybus, C and Greenberg, DE},
title = {Antisense phosphorodiamidate morpholino oligomers retain activity in Burkholderia cepacia complex biofilm.},
journal = {Frontiers in microbiology},
volume = {16},
number = {},
pages = {1660799},
pmid = {41064251},
issn = {1664-302X},
abstract = {BACKGROUND: Members of the Burkholderia cepacia complex (Bcc) are known to cause severe pulmonary infections in immunocompromised hosts, namely individuals with cystic fibrosis (CF) and chronic granulomatous disease (CGD). Due to innate antibiotic-resistant phenotypes and the formation of protective biofilms, Bcc bacteria are difficult to eradicate from colonized lungs using traditional antibiotics. An alternative therapeutic approach involves the use of antisense molecules, specifically peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs). Previously, we found that PPMOs targeting the acyl carrier protein (AcpP) can reduce the burden of planktonic Bcc bacteria.
METHODS: Antimicrobial activities of AcpP PPMOs were assessed against established biofilms produced by Bcc clinical isolates, in which viable cells, biomass, and metabolic activity were enumerated. Bactericidal effects were further evaluated by microscopy. Cytotoxicity of these molecules was tested in human pulmonary cell lines.
RESULTS: AcpP PPMO treatment resulted in over three-log reductions (p < 0.0001) in biofilm burden across five clinical isolates of Bcc that were tested. A dose-dependent effect was observed (5-40 μΜ). This effect was visualized using confocal and scanning electron microscopy. We further demonstrated that PPMOs associate with bacterial cells in a time-dependent fashion using a fluorescently labeled AcpP PPMO with B. cenocepacia K56-2 DsRed. Finally, alveolar cells retained viability with AcpP PPMOs at bactericidal dosages.
CONCLUSION: The Bcc biofilm setting is not a deterrent against PPMO delivery or antimicrobial activity. This is supported by the colocalization of AcpP PPMOs with cells, membrane destruction, loss of cell viability, and biomass reduction. Collectively, these data provide evidence that AcpP PPMOs are a promising therapeutic strategy in the treatment of Bcc infections.},
}
RevDate: 2025-10-08
Variation in type IV pilus stability modulates DNA-uptake and biofilm formation.
The Journal of biological chemistry pii:S0021-9258(25)02639-0 [Epub ahead of print].
Type IV pili are helical filaments composed of protein subunits which are produced by numerous taxa of bacteria, including Acinetobacter. Type IV pili are extended out from the cell by extension enzyme complexes, which extract subunits from the membrane and insert them into the base of the filament, but can also be retracted by reverse rotation catalyzed by a retraction enzyme. Type IV pili have diverse functions, including twitching motility and DNA-uptake, which require retraction, and host adhesion and bacterial aggregation, which do not. Acinetobacter bacteria, including International Clone I (IC-I) and International Clone II (IC-II) strains, show variable phenotypes in assays of type IV pilus-dependent functions. Here, we show this variation is the result of differentiation of type IV pilus subtypes in Acinetobacter, which we defined based on the sequence of the major subunit, PilA. These subtypes show variable efficiency in pilus retraction between pilus subtypes, and from that, a differential balance between retraction-dependent and retraction-independent functions. In both naturally-occurring pilA variants from the IC-I and IC-II groups and isogenic strains complemented with IC-I or IC-II pilA, the IC-I pilus subtype promotes greater twitching motility and DNA-uptake while the IC-II pilus subtype promotes biofilm formation while showing reduced capacity for DNA-uptake and twitching motility, similar to a retraction-deficient mutant and consistent with the hypothesis that pilus retraction of the IC-II pilus is naturally deficient. This defect in retraction was sufficient to increase the level of piliation on the cell surface when we compared the yields of T4P sheared from the cell surface from IC-I pilA and IC-II pilA complements in an isogenic background. Complementation with IC-II pilA results in greater levels of surface PilA per cell than equivalent complementation with an IC-I pilA gene. Additionally, direct comparisons of pilus stability between type IV pili isolated from IC-I pilA and IC-II pilA complements show greater thermostability for the IC-II pili, supporting the hypothesis that pilus stability can impede retraction and increase piliation.
Additional Links: PMID-41062070
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@article {pmid41062070,
year = {2025},
author = {Yu, Y and Mahdi, R and Al-Hilfy Leon, A and Vo, N and Lofgren, R and Mutabazi, JL and Piepenbrink, KH},
title = {Variation in type IV pilus stability modulates DNA-uptake and biofilm formation.},
journal = {The Journal of biological chemistry},
volume = {},
number = {},
pages = {110787},
doi = {10.1016/j.jbc.2025.110787},
pmid = {41062070},
issn = {1083-351X},
abstract = {Type IV pili are helical filaments composed of protein subunits which are produced by numerous taxa of bacteria, including Acinetobacter. Type IV pili are extended out from the cell by extension enzyme complexes, which extract subunits from the membrane and insert them into the base of the filament, but can also be retracted by reverse rotation catalyzed by a retraction enzyme. Type IV pili have diverse functions, including twitching motility and DNA-uptake, which require retraction, and host adhesion and bacterial aggregation, which do not. Acinetobacter bacteria, including International Clone I (IC-I) and International Clone II (IC-II) strains, show variable phenotypes in assays of type IV pilus-dependent functions. Here, we show this variation is the result of differentiation of type IV pilus subtypes in Acinetobacter, which we defined based on the sequence of the major subunit, PilA. These subtypes show variable efficiency in pilus retraction between pilus subtypes, and from that, a differential balance between retraction-dependent and retraction-independent functions. In both naturally-occurring pilA variants from the IC-I and IC-II groups and isogenic strains complemented with IC-I or IC-II pilA, the IC-I pilus subtype promotes greater twitching motility and DNA-uptake while the IC-II pilus subtype promotes biofilm formation while showing reduced capacity for DNA-uptake and twitching motility, similar to a retraction-deficient mutant and consistent with the hypothesis that pilus retraction of the IC-II pilus is naturally deficient. This defect in retraction was sufficient to increase the level of piliation on the cell surface when we compared the yields of T4P sheared from the cell surface from IC-I pilA and IC-II pilA complements in an isogenic background. Complementation with IC-II pilA results in greater levels of surface PilA per cell than equivalent complementation with an IC-I pilA gene. Additionally, direct comparisons of pilus stability between type IV pili isolated from IC-I pilA and IC-II pilA complements show greater thermostability for the IC-II pili, supporting the hypothesis that pilus stability can impede retraction and increase piliation.},
}
RevDate: 2025-10-08
Anion-exchange membrane coupled with methane-fed biofilm enables efficient co-removal of perchlorate and nitrate.
Water research, 288(Pt B):124687 pii:S0043-1354(25)01590-8 [Epub ahead of print].
Perchlorate and nitrate frequently co-occur in contaminated water posing significant risks to human health and the environment. However, their simultaneous and highly efficient removal remains a critical technical challenge. We report a high-performance hybrid system integrating Donnan exchange through an anion-exchange membrane (AEM) with reduction in methane-fed bio-reactor (AEM-MBfR), achieving high ClO4[-] and NO3[-] removal efficiencies. The AEM-MBfR attained volumetric removal fluxes up to 902.17 μg ClO4[-]·L[-1]·d[-1] and 22.74 mg N·L[-1]·d[-1], representing 9.6- and 1.6-fold increases, respectively, over a standalone MBfR. Mechanistic analysis revealed that enzyme-independent Donnan dialysis in the AEM module enriched ClO4[-] into the MBfR zone, alleviating the competitive advantage of NO3[-] reduction over ClO4[-]. This enrichment significantly enhanced bioreduction kinetics, enabling sustained high-throughput treatment. Multi-omics profiling identified a syntrophic microbial network dominated by Methylocystis, Methylosinus and Hyphomicrobium, with elevated transcription of key functional genes that drive ClO4[-] and NO3[-] reduction. Notably, VFAs-mediated electron transfer facilitated tight metabolic coupling between methanotrophs and denitrifiers. Compared to other MBfRs, the AEM-MBfR achieved one of the highest reported ClO4[-] removal fluxes. Coupled with the low cost of methane and NaCl, this study demonstrates a scalable and economically viable strategy for remediating anion-contaminated water through membrane-enhanced microbial processes.
Additional Links: PMID-41061652
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@article {pmid41061652,
year = {2025},
author = {Zhang, LD and Lai, CY and Oren, Y and Gilron, J and Ronen, Z and Zhao, HP},
title = {Anion-exchange membrane coupled with methane-fed biofilm enables efficient co-removal of perchlorate and nitrate.},
journal = {Water research},
volume = {288},
number = {Pt B},
pages = {124687},
doi = {10.1016/j.watres.2025.124687},
pmid = {41061652},
issn = {1879-2448},
abstract = {Perchlorate and nitrate frequently co-occur in contaminated water posing significant risks to human health and the environment. However, their simultaneous and highly efficient removal remains a critical technical challenge. We report a high-performance hybrid system integrating Donnan exchange through an anion-exchange membrane (AEM) with reduction in methane-fed bio-reactor (AEM-MBfR), achieving high ClO4[-] and NO3[-] removal efficiencies. The AEM-MBfR attained volumetric removal fluxes up to 902.17 μg ClO4[-]·L[-1]·d[-1] and 22.74 mg N·L[-1]·d[-1], representing 9.6- and 1.6-fold increases, respectively, over a standalone MBfR. Mechanistic analysis revealed that enzyme-independent Donnan dialysis in the AEM module enriched ClO4[-] into the MBfR zone, alleviating the competitive advantage of NO3[-] reduction over ClO4[-]. This enrichment significantly enhanced bioreduction kinetics, enabling sustained high-throughput treatment. Multi-omics profiling identified a syntrophic microbial network dominated by Methylocystis, Methylosinus and Hyphomicrobium, with elevated transcription of key functional genes that drive ClO4[-] and NO3[-] reduction. Notably, VFAs-mediated electron transfer facilitated tight metabolic coupling between methanotrophs and denitrifiers. Compared to other MBfRs, the AEM-MBfR achieved one of the highest reported ClO4[-] removal fluxes. Coupled with the low cost of methane and NaCl, this study demonstrates a scalable and economically viable strategy for remediating anion-contaminated water through membrane-enhanced microbial processes.},
}
RevDate: 2025-10-08
Characterization of a novel phage vB_YenP_WW2 for the inhibition against Yersinia enterocolitica biofilm and application in raw meat and milk.
International journal of food microbiology, 444:111468 pii:S0168-1605(25)00413-1 [Epub ahead of print].
Yersinia enterocolitica is a significant zoonotic pathogen that causes severe gastrointestinal disease. In this study, vB_YenP_WW2 (WW2), a novel bacteriophage specific to Y. enterocolitica, was isolated and characterized. Stability analysis revealed that WW2 can retain its activity across a wide range of pH (4-12) and temperatures (4-60 °C). Host range analysis showed that WW2 exhibits broad lytic activity against various Y. enterocolitica strains, with a lysis rate of 27 %. Within 3 h, WW2 effectively reduced the bacterial load in raw meat and milk to undetectable levels. Additionally, WW2 significantly inhibited biofilm formation on polyethylene over 36 h and reduced biofilm formation by 70 % on stainless steel after 18 h of incubation. Compared to previously reported Y. enterocolitica phages, WW2 displayed a shorter latent period and stronger preventive effects against both Y. enterocolitica and its biofilms. These results suggested that WW2 holds promise as a novel antimicrobial agent against Y. enterocolitica.
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@article {pmid41061487,
year = {2025},
author = {Wang, Z and Liu, M and Xu, T and Yuan, X and Liu, Z and Chen, H and Zhang, J and Ding, Y and Wu, Q and Wang, J},
title = {Characterization of a novel phage vB_YenP_WW2 for the inhibition against Yersinia enterocolitica biofilm and application in raw meat and milk.},
journal = {International journal of food microbiology},
volume = {444},
number = {},
pages = {111468},
doi = {10.1016/j.ijfoodmicro.2025.111468},
pmid = {41061487},
issn = {1879-3460},
abstract = {Yersinia enterocolitica is a significant zoonotic pathogen that causes severe gastrointestinal disease. In this study, vB_YenP_WW2 (WW2), a novel bacteriophage specific to Y. enterocolitica, was isolated and characterized. Stability analysis revealed that WW2 can retain its activity across a wide range of pH (4-12) and temperatures (4-60 °C). Host range analysis showed that WW2 exhibits broad lytic activity against various Y. enterocolitica strains, with a lysis rate of 27 %. Within 3 h, WW2 effectively reduced the bacterial load in raw meat and milk to undetectable levels. Additionally, WW2 significantly inhibited biofilm formation on polyethylene over 36 h and reduced biofilm formation by 70 % on stainless steel after 18 h of incubation. Compared to previously reported Y. enterocolitica phages, WW2 displayed a shorter latent period and stronger preventive effects against both Y. enterocolitica and its biofilms. These results suggested that WW2 holds promise as a novel antimicrobial agent against Y. enterocolitica.},
}
RevDate: 2025-10-08
Intracellular glutamine fluctuates with nitrogen availability and regulates Mycobacterium smegmatis biofilm formation.
Journal of bacteriology [Epub ahead of print].
Nontuberculous mycobacteria (NTM) can form biofilms during human infection and in household plumbing systems, so understanding biofilm regulation could help us better treat and prevent NTM infections. Glucose drives NTM aggregation in vitro, and ammonium inhibits it, but the regulatory systems controlling this early step in biofilm formation are not understood. Here, in the model NTM Mycobacterium smegmatis, we show that multiple carbon and nitrogen sources have similar impacts on aggregation as glucose and ammonium , suggesting that the response to these nutrients is general and likely sensed through downstream, integrated signals. Next, we performed a transposon screen in M. smegmatis to uncover these putative regulatory nodes. Our screen revealed that mutating specific genes in the purine and pyrimidine biosynthesis pathways caused an aggregation defect, but supplementing with adenosine and guanosine had no impact on aggregation either in a purF mutant or WT. Realizing that the only genes we hit in purine or pyrimidine biosynthesis were those that utilized glutamine as a nitrogen donor, we pivoted to the hypothesis that intracellular glutamine could be a nitrogen-responsive node affecting aggregation. We tested this hypothesis in a defined M63 medium using targeted mass spectrometry. Indeed, intracellular glutamine increased with nitrogen availability and correlated with planktonic growth. Furthermore, a garA mutant, which has an artificially expanded glutamine pool in the growth phase, grew solely as planktonic cells even without nitrogen supplementation. Altogether, these results establish that intracellular glutamine controls M. smegmatis aggregation, and they introduce flux-dependent sensors as key components of the NTM biofilm regulatory system.IMPORTANCEA subset of nontuberculous mycobacteria (NTM), including Mycobacterium abscessus, are opportunistic pathogens that can cause severe pulmonary infections. Biofilm formation renders M. abscessus more tolerant to antibiotics; hence, the ability to inhibit NTM biofilm formation could help us better prevent and treat NTM infections. However, the regulatory systems controlling NTM biofilm formation, which could include targets for anti-biofilm therapeutics, are poorly understood. The significance of this work is that it reveals intracellular glutamine as an important node controlling the initiation of biofilm formation in the model NTM Mycobacterium smegmatis. Building on this foundation, future studies will investigate how NTM biofilms can be dispersed by altering glutamine levels and will describe how NTM translates intracellular glutamine to the alteration of surface adhesins.
Additional Links: PMID-41060069
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@article {pmid41060069,
year = {2025},
author = {Varner, E and Meyer, M and Whalen, J and Wang, Y-H and Rodriguez, C and Malik, I and Mullet, SJ and Gelhaus, SL and DePas, WH},
title = {Intracellular glutamine fluctuates with nitrogen availability and regulates Mycobacterium smegmatis biofilm formation.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {e0025225},
doi = {10.1128/jb.00252-25},
pmid = {41060069},
issn = {1098-5530},
abstract = {Nontuberculous mycobacteria (NTM) can form biofilms during human infection and in household plumbing systems, so understanding biofilm regulation could help us better treat and prevent NTM infections. Glucose drives NTM aggregation in vitro, and ammonium inhibits it, but the regulatory systems controlling this early step in biofilm formation are not understood. Here, in the model NTM Mycobacterium smegmatis, we show that multiple carbon and nitrogen sources have similar impacts on aggregation as glucose and ammonium , suggesting that the response to these nutrients is general and likely sensed through downstream, integrated signals. Next, we performed a transposon screen in M. smegmatis to uncover these putative regulatory nodes. Our screen revealed that mutating specific genes in the purine and pyrimidine biosynthesis pathways caused an aggregation defect, but supplementing with adenosine and guanosine had no impact on aggregation either in a purF mutant or WT. Realizing that the only genes we hit in purine or pyrimidine biosynthesis were those that utilized glutamine as a nitrogen donor, we pivoted to the hypothesis that intracellular glutamine could be a nitrogen-responsive node affecting aggregation. We tested this hypothesis in a defined M63 medium using targeted mass spectrometry. Indeed, intracellular glutamine increased with nitrogen availability and correlated with planktonic growth. Furthermore, a garA mutant, which has an artificially expanded glutamine pool in the growth phase, grew solely as planktonic cells even without nitrogen supplementation. Altogether, these results establish that intracellular glutamine controls M. smegmatis aggregation, and they introduce flux-dependent sensors as key components of the NTM biofilm regulatory system.IMPORTANCEA subset of nontuberculous mycobacteria (NTM), including Mycobacterium abscessus, are opportunistic pathogens that can cause severe pulmonary infections. Biofilm formation renders M. abscessus more tolerant to antibiotics; hence, the ability to inhibit NTM biofilm formation could help us better prevent and treat NTM infections. However, the regulatory systems controlling NTM biofilm formation, which could include targets for anti-biofilm therapeutics, are poorly understood. The significance of this work is that it reveals intracellular glutamine as an important node controlling the initiation of biofilm formation in the model NTM Mycobacterium smegmatis. Building on this foundation, future studies will investigate how NTM biofilms can be dispersed by altering glutamine levels and will describe how NTM translates intracellular glutamine to the alteration of surface adhesins.},
}
RevDate: 2025-10-08
CmpDate: 2025-10-08
Novel Insights Into the Struggle Against Biofilm: The PsyOmp38 Protein From the Antarctic Marine Bacterium Psychrobacter sp. TAE2020.
Microbial biotechnology, 18(10):e70249.
Antibiofilm molecules can enhance the effectiveness of antibiotics and prevent biofilm formation. Antarctic marine bacteria have been found to secrete antibiofilm molecules, likely as part of a strategy for competitive survival. The protein-polysaccharide complex CATASAN, produced by the Antarctic bacterium Psychrobacter sp. TAE2020, has been shown to interfere with all stages of Staphylococcus epidermidis biofilm development. This study investigates the contribution of PsyOmp38, the protein component of CATASAN, to the complex's antibiofilm activity. The protein was heterologously expressed in Escherichia coli, purified, and characterised, revealing its ability to inhibit Staphylococcus epidermidis adhesion to surfaces, interfere with biofilm formation, and disrupt mature biofilms. Following biocompatibility assessment, PsyOmp38 was tested in combination with vancomycin as a potential treatment for established infections, revealing a reduction in the minimum biofilm eradication concentration (MBEC) of vancomycin. The potential of PsyOmp38 for material functionalisation was also explored. The protein was deposited onto silicone-based surfaces, and the coated materials were tested in a continuous-flow system that simulated real-life conditions. Additionally, the three-dimensional structure of PsyOmp38 was predicted and compared with homologous proteins. The structural analysis not only revealed the unique features of PsyOmp38 but also provided important insights into the molecular mechanisms underlying its antibiofilm activity.
Additional Links: PMID-41058107
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PubMed:
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@article {pmid41058107,
year = {2025},
author = {Olimpo, D and D'Angelo, C and Imbimbo, P and Morelli, M and Tutino, ML and Carpentieri, A and Monti, DM and Notomista, E and Parrilli, E},
title = {Novel Insights Into the Struggle Against Biofilm: The PsyOmp38 Protein From the Antarctic Marine Bacterium Psychrobacter sp. TAE2020.},
journal = {Microbial biotechnology},
volume = {18},
number = {10},
pages = {e70249},
doi = {10.1111/1751-7915.70249},
pmid = {41058107},
issn = {1751-7915},
mesh = {*Biofilms/drug effects/growth & development ; *Psychrobacter/genetics/metabolism/chemistry ; Antarctic Regions ; *Staphylococcus epidermidis/drug effects/physiology ; *Bacterial Proteins/genetics/pharmacology/metabolism/chemistry ; Anti-Bacterial Agents/pharmacology/metabolism ; Escherichia coli/genetics/metabolism ; Bacterial Adhesion/drug effects ; Microbial Sensitivity Tests ; Vancomycin/pharmacology ; Recombinant Proteins/genetics/pharmacology/metabolism/isolation & purification ; },
abstract = {Antibiofilm molecules can enhance the effectiveness of antibiotics and prevent biofilm formation. Antarctic marine bacteria have been found to secrete antibiofilm molecules, likely as part of a strategy for competitive survival. The protein-polysaccharide complex CATASAN, produced by the Antarctic bacterium Psychrobacter sp. TAE2020, has been shown to interfere with all stages of Staphylococcus epidermidis biofilm development. This study investigates the contribution of PsyOmp38, the protein component of CATASAN, to the complex's antibiofilm activity. The protein was heterologously expressed in Escherichia coli, purified, and characterised, revealing its ability to inhibit Staphylococcus epidermidis adhesion to surfaces, interfere with biofilm formation, and disrupt mature biofilms. Following biocompatibility assessment, PsyOmp38 was tested in combination with vancomycin as a potential treatment for established infections, revealing a reduction in the minimum biofilm eradication concentration (MBEC) of vancomycin. The potential of PsyOmp38 for material functionalisation was also explored. The protein was deposited onto silicone-based surfaces, and the coated materials were tested in a continuous-flow system that simulated real-life conditions. Additionally, the three-dimensional structure of PsyOmp38 was predicted and compared with homologous proteins. The structural analysis not only revealed the unique features of PsyOmp38 but also provided important insights into the molecular mechanisms underlying its antibiofilm activity.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Psychrobacter/genetics/metabolism/chemistry
Antarctic Regions
*Staphylococcus epidermidis/drug effects/physiology
*Bacterial Proteins/genetics/pharmacology/metabolism/chemistry
Anti-Bacterial Agents/pharmacology/metabolism
Escherichia coli/genetics/metabolism
Bacterial Adhesion/drug effects
Microbial Sensitivity Tests
Vancomycin/pharmacology
Recombinant Proteins/genetics/pharmacology/metabolism/isolation & purification
RevDate: 2025-10-07
Correction: Eco‑friendly biosynthesis of gold nanoparticles from Amphimedon compressa with antibacterial, antioxidant, anti-inflammatory, anti-biofilm, and insecticidal properties against diseases vectors.
Scientific reports, 15(1):34847 pii:10.1038/s41598-025-22309-3.
Additional Links: PMID-41057678
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PubMed:
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@article {pmid41057678,
year = {2025},
author = {Mekky, AE and Saied, E and Al-Habibi, MM and Shouaib, ZA and Hasaballah, AI and Rashed, ME and Khalel, AF and Alshammari, AN and Youssef, FS and Al-Shahat, AM and Alfaifi, MY and Elbehairi, SEI and Aufy, M and Selim, TA},
title = {Correction: Eco‑friendly biosynthesis of gold nanoparticles from Amphimedon compressa with antibacterial, antioxidant, anti-inflammatory, anti-biofilm, and insecticidal properties against diseases vectors.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {34847},
doi = {10.1038/s41598-025-22309-3},
pmid = {41057678},
issn = {2045-2322},
}
RevDate: 2025-10-07
Efficacy of Supplementary Irrigation Methods Against Bacterial Biofilm-Infected Root Canals Prepared With Minimally Invasive and Conventional Techniques.
Australian endodontic journal : the journal of the Australian Society of Endodontology Inc [Epub ahead of print].
This study evaluated the effectiveness of the GentleWave system (GWS), laser-activated irrigation (LAI), ultrasonic-activated irrigation (UAI) and sonic irrigation (SI) in removing a three-species biofilm from infected root canals prepared using minimally invasive techniques (MIT) and conventional instrumentation techniques (CIT). One hundred and ten single-canalled mandibular premolars were infected with the biofilm and assigned to five groups based on the supplementary irrigation method used. Biofilm removal was assessed using confocal laser scanning microscopy and scanning electron microscopy. In the CIT group, GWS resulted in a significantly higher proportion of dead cells compared to UAI and SI (p < 0.05), with no significant difference between GWS and LAI. In the MIT group, no significant differences were observed among the irrigation methods (p > 0.05). Although none of the approaches completely eliminated the biofilm, GWS and LAI were more effective than UAI and SI.
Additional Links: PMID-41055238
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PubMed:
Citation:
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@article {pmid41055238,
year = {2025},
author = {Soimu, G and Parolia, A and Masiero, AV and Qian, F and Moninger, T and Banas, JA and Teixeira, FB},
title = {Efficacy of Supplementary Irrigation Methods Against Bacterial Biofilm-Infected Root Canals Prepared With Minimally Invasive and Conventional Techniques.},
journal = {Australian endodontic journal : the journal of the Australian Society of Endodontology Inc},
volume = {},
number = {},
pages = {},
doi = {10.1111/aej.70024},
pmid = {41055238},
issn = {1747-4477},
support = {202404307//Univeristy of Iowa College of Dentsitry/ ; },
abstract = {This study evaluated the effectiveness of the GentleWave system (GWS), laser-activated irrigation (LAI), ultrasonic-activated irrigation (UAI) and sonic irrigation (SI) in removing a three-species biofilm from infected root canals prepared using minimally invasive techniques (MIT) and conventional instrumentation techniques (CIT). One hundred and ten single-canalled mandibular premolars were infected with the biofilm and assigned to five groups based on the supplementary irrigation method used. Biofilm removal was assessed using confocal laser scanning microscopy and scanning electron microscopy. In the CIT group, GWS resulted in a significantly higher proportion of dead cells compared to UAI and SI (p < 0.05), with no significant difference between GWS and LAI. In the MIT group, no significant differences were observed among the irrigation methods (p > 0.05). Although none of the approaches completely eliminated the biofilm, GWS and LAI were more effective than UAI and SI.},
}
RevDate: 2025-10-07
Reversibly Cross-Linked Asymmetric Hybrid Open-Polysilsesquioxane Films Enhancing Clotrimazole Bioavailability and Anti-Candida Mature Biofilm Activity for Vaginal Therapy.
ACS applied materials & interfaces [Epub ahead of print].
Vulvovaginal candidiasis, primarily caused by Candida albicans, presents a significant therapeutic challenge due to fungal biofilm formation and the poor aqueous solubility of azole antifungals like clotrimazole, CLT. Films are increasingly favored as antimicrobial drug carriers due to their capacity to provide prolonged vaginal retention, extended shelf life, and simplified storage compared to traditional drug forms. Current film formulations, however, often suffer from nonuniform drug distribution, uncontrolled drug release, and compromised structural integrity. To overcome these limitations, we developed novel, water-swellable polymeric networks designed for enhanced clotrimazole bioavailability and potent anti-Candida biofilm activity. Our strategy involved the reversible cross-linking of unique asymmetric open-Polyhedral Oligomeric Silsesquioxane (POSS) cages, functionalized with both hydrophobic, i.e., phenyl (IC-POSS[Ph]) or isobutyl (IC-POSS[iBu]) groups and bearing hydrophilic 1,2-diol moieties, with poly(dimethylacrylamide-2-acrylamidephenylboronic acid) (P(DMAM-2-AAPBA)) copolymers. We tailored the copolymer composition to achieve precise control over the network cross-linking density. Comprehensive characterization, including [11]B NMR spectroscopy, differential scanning calorimetry, rheology, and SEM-EDS (scanning electron microscopy-energy dispersive X-ray spectroscopy), elucidated the structure-property relationships. We demonstrated that IC-POSS[Ph] cages intrinsically prevent CLT crystallization, likely via π-π-stacking interactions, facilitating homogeneous drug distribution. Conversely, while IC-POSS[iBu] cages showed less inherent drug compatibility, the P(DMAM-2-AAPBA) copolymers were crucial for achieving uniform CLT dispersion within these networks. Our studies revealed that higher 2-AAPBA content in the copolymer increased network cross-linking density, leading to slower drug release. Moreover, π-π interactions between IC-POSS[Ph] cages in the networks contributed to a reduced swelling capacity and evidently slower drug release. Crucially, biological evaluations confirmed that these CLT-loaded polymeric films significantly enhanced antifungal efficacy against both planktonic C. albicans strains (ATCC 10231 and SC5314) and mature Candida biofilms, outperforming free CLT. This superior performance is attributed to the networks' ability to maintain CLT in the molecular state and enable its controlled release, thereby improving its bioavailability at the target site. The elaborated films also exhibited good cytocompatibility. This work highlights how subtle structural modifications in network components are crucial to achieving desired biological functions, representing a promising advance for antifungal drug delivery and, in general, hydrophobic drug carriers in various biomedical applications.
Additional Links: PMID-41054241
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PubMed:
Citation:
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@article {pmid41054241,
year = {2025},
author = {Madej-Gajewska, M and Janek, T and Gosecka, M and Gosecki, M and Urbaniak, M and Wielgus, E and John, Ł},
title = {Reversibly Cross-Linked Asymmetric Hybrid Open-Polysilsesquioxane Films Enhancing Clotrimazole Bioavailability and Anti-Candida Mature Biofilm Activity for Vaginal Therapy.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.5c12791},
pmid = {41054241},
issn = {1944-8252},
abstract = {Vulvovaginal candidiasis, primarily caused by Candida albicans, presents a significant therapeutic challenge due to fungal biofilm formation and the poor aqueous solubility of azole antifungals like clotrimazole, CLT. Films are increasingly favored as antimicrobial drug carriers due to their capacity to provide prolonged vaginal retention, extended shelf life, and simplified storage compared to traditional drug forms. Current film formulations, however, often suffer from nonuniform drug distribution, uncontrolled drug release, and compromised structural integrity. To overcome these limitations, we developed novel, water-swellable polymeric networks designed for enhanced clotrimazole bioavailability and potent anti-Candida biofilm activity. Our strategy involved the reversible cross-linking of unique asymmetric open-Polyhedral Oligomeric Silsesquioxane (POSS) cages, functionalized with both hydrophobic, i.e., phenyl (IC-POSS[Ph]) or isobutyl (IC-POSS[iBu]) groups and bearing hydrophilic 1,2-diol moieties, with poly(dimethylacrylamide-2-acrylamidephenylboronic acid) (P(DMAM-2-AAPBA)) copolymers. We tailored the copolymer composition to achieve precise control over the network cross-linking density. Comprehensive characterization, including [11]B NMR spectroscopy, differential scanning calorimetry, rheology, and SEM-EDS (scanning electron microscopy-energy dispersive X-ray spectroscopy), elucidated the structure-property relationships. We demonstrated that IC-POSS[Ph] cages intrinsically prevent CLT crystallization, likely via π-π-stacking interactions, facilitating homogeneous drug distribution. Conversely, while IC-POSS[iBu] cages showed less inherent drug compatibility, the P(DMAM-2-AAPBA) copolymers were crucial for achieving uniform CLT dispersion within these networks. Our studies revealed that higher 2-AAPBA content in the copolymer increased network cross-linking density, leading to slower drug release. Moreover, π-π interactions between IC-POSS[Ph] cages in the networks contributed to a reduced swelling capacity and evidently slower drug release. Crucially, biological evaluations confirmed that these CLT-loaded polymeric films significantly enhanced antifungal efficacy against both planktonic C. albicans strains (ATCC 10231 and SC5314) and mature Candida biofilms, outperforming free CLT. This superior performance is attributed to the networks' ability to maintain CLT in the molecular state and enable its controlled release, thereby improving its bioavailability at the target site. The elaborated films also exhibited good cytocompatibility. This work highlights how subtle structural modifications in network components are crucial to achieving desired biological functions, representing a promising advance for antifungal drug delivery and, in general, hydrophobic drug carriers in various biomedical applications.},
}
RevDate: 2025-10-06
CmpDate: 2025-10-07
Surface roughness and biofilm formation on tooth-colored restorative materials immersed in food-simulating liquids.
BMC oral health, 25(1):1543.
BACKGROUND: This study aimed to evaluate the surface roughness and biofilm formation of different restorative materials immersed in food-simulating liquids (FSLs), and to investigate the relationship between these parameters.
METHODS: A total of 220 disc-shaped specimens (8 mm diameter × 2 mm depth) were prepared using five restorative materials: alkasite [Cention N], giomer [Beautifil II], ormocer [Admira Fusion], direct composite [G-ænial A'Chord], and indirect composite [Gradia Plus] (n = 44 per material). Each material group was divided into four subgroups (n = 11), immersed in one of four solutions-heptane, ethanol, citric acid, or artificial saliva (control)-for 7 days, resulting in a total of 20 experimental subgroups. In each subgroup of 11 specimens, 10 were used for both surface roughness measurements (before and after immersion) and bacterial adhesion assessment using the colony-forming unit (CFU) method, while one was reserved for scanning electron microscopy (SEM) analysis. Additionally, data were tested for normality using the Shapiro-Wilk test, and statistical analyses were performed using robust ANOVA and Bonferroni post hoc tests (p < 0.05).
RESULTS: Alkasite and giomer exhibited significantly higher surface roughness values, whereas indirect composite presented the lowest (p < 0.001). Regarding the immersion solutions, citric acid led to the most pronounced increase in surface roughness compared to the other solutions, while heptane had the least impact (p < 0.001). Consistent with these findings, alkasite and giomer demonstrated the highest levels of bacterial adhesion, in contrast to direct and indirect composite, which showed the lowest (p = 0.008). Furthermore, citric acid resulted in the greatest microbial retention among the solutions, and heptane the least (p < 0.001).
CONCLUSIONS: The restorative materials exhibited varying degrees of susceptibility to the tested solutions. Alkasite and giomer showed the most pronounced surface changes, whereas the indirect composite group was the least affected. Among the solutions, citric acid caused the greatest surface alterations, while heptane had the least impact. Surface roughness emerged as a key factor influencing microbial retention on restorative materials.
Additional Links: PMID-41053638
PubMed:
Citation:
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@article {pmid41053638,
year = {2025},
author = {Sahin, MA and Yenidunya, OG and Kaleli, I and Atca, M},
title = {Surface roughness and biofilm formation on tooth-colored restorative materials immersed in food-simulating liquids.},
journal = {BMC oral health},
volume = {25},
number = {1},
pages = {1543},
pmid = {41053638},
issn = {1472-6831},
support = {#2023DİŞF007//Scientific Research Projects Committee of Pamukkale University with Grant/ ; },
mesh = {*Biofilms/growth & development ; Surface Properties ; Composite Resins/chemistry ; Bacterial Adhesion ; *Dental Materials/chemistry ; Citric Acid/chemistry ; Microscopy, Electron, Scanning ; *Food ; Materials Testing ; Saliva, Artificial/chemistry ; Dental Restoration, Permanent ; Humans ; },
abstract = {BACKGROUND: This study aimed to evaluate the surface roughness and biofilm formation of different restorative materials immersed in food-simulating liquids (FSLs), and to investigate the relationship between these parameters.
METHODS: A total of 220 disc-shaped specimens (8 mm diameter × 2 mm depth) were prepared using five restorative materials: alkasite [Cention N], giomer [Beautifil II], ormocer [Admira Fusion], direct composite [G-ænial A'Chord], and indirect composite [Gradia Plus] (n = 44 per material). Each material group was divided into four subgroups (n = 11), immersed in one of four solutions-heptane, ethanol, citric acid, or artificial saliva (control)-for 7 days, resulting in a total of 20 experimental subgroups. In each subgroup of 11 specimens, 10 were used for both surface roughness measurements (before and after immersion) and bacterial adhesion assessment using the colony-forming unit (CFU) method, while one was reserved for scanning electron microscopy (SEM) analysis. Additionally, data were tested for normality using the Shapiro-Wilk test, and statistical analyses were performed using robust ANOVA and Bonferroni post hoc tests (p < 0.05).
RESULTS: Alkasite and giomer exhibited significantly higher surface roughness values, whereas indirect composite presented the lowest (p < 0.001). Regarding the immersion solutions, citric acid led to the most pronounced increase in surface roughness compared to the other solutions, while heptane had the least impact (p < 0.001). Consistent with these findings, alkasite and giomer demonstrated the highest levels of bacterial adhesion, in contrast to direct and indirect composite, which showed the lowest (p = 0.008). Furthermore, citric acid resulted in the greatest microbial retention among the solutions, and heptane the least (p < 0.001).
CONCLUSIONS: The restorative materials exhibited varying degrees of susceptibility to the tested solutions. Alkasite and giomer showed the most pronounced surface changes, whereas the indirect composite group was the least affected. Among the solutions, citric acid caused the greatest surface alterations, while heptane had the least impact. Surface roughness emerged as a key factor influencing microbial retention on restorative materials.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
Surface Properties
Composite Resins/chemistry
Bacterial Adhesion
*Dental Materials/chemistry
Citric Acid/chemistry
Microscopy, Electron, Scanning
*Food
Materials Testing
Saliva, Artificial/chemistry
Dental Restoration, Permanent
Humans
RevDate: 2025-10-06
CmpDate: 2025-10-06
Farnesol emulsion for elimination of Pseudomonas aeruginosa biofilm in a 3D airway model of cystic fibrosis.
Biofilm, 10:100317.
Cystic fibrosis (CF), a life-shortening genetic disease, is hallmarked by mucus obstruction, respiratory deficiency, and chronic bacterial infections. Pseudomonas aeruginosa is the most common virulent respiratory pathogen that is detrimental to the overall survival of CF patients. Here we evaluate the efficacy of farnesol emulsion, a broad-spectrum agent recently used to combat P. aeruginosa biofilm infections, for reducing P. aeruginosa infections in CF using a three-dimensional (3D) airway "organ tissue equivalent" (OTE) model. OTEs are fabricated using cells derived from human primary cells sourced from CF donors (CF-OTEs), which accurately recapitulate multiple key traits of human CF airways, including increased mucin accumulation and lower cilium beating frequency, compared to OTEs derived from normal donors (N-OTEs). The OTE model closely approximates the native CF condition to provide a platform where both mucoid and nonmucoid P. aeruginosa establish biofilms. Luminescence quantification and viable bacterial enumeration demonstrated that more P. aeruginosa biofilm mass developed upon CF-OTEs compared to non-CF (normal) OTEs. The capability to establish infection and biofilm formation, without acute tissue toxicity, allows for rapid discrimination of therapeutic efficacy in an accurate, human in vitro model. Farnesol emulsion disrupted P. aeruginosa biofilms in situ and also protected OTE lung cell viability. We propose that the 3D airway OTE infection model is a reliable preclinical tool for CF drug screening, with farnesol emulsion being a prospective drug candidate to treat P. aeruginosa biofilm infections in CF.
Additional Links: PMID-41050920
PubMed:
Citation:
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@article {pmid41050920,
year = {2025},
author = {Tan, L and Sutton, K and Murphy, SV and Levi, N},
title = {Farnesol emulsion for elimination of Pseudomonas aeruginosa biofilm in a 3D airway model of cystic fibrosis.},
journal = {Biofilm},
volume = {10},
number = {},
pages = {100317},
pmid = {41050920},
issn = {2590-2075},
abstract = {Cystic fibrosis (CF), a life-shortening genetic disease, is hallmarked by mucus obstruction, respiratory deficiency, and chronic bacterial infections. Pseudomonas aeruginosa is the most common virulent respiratory pathogen that is detrimental to the overall survival of CF patients. Here we evaluate the efficacy of farnesol emulsion, a broad-spectrum agent recently used to combat P. aeruginosa biofilm infections, for reducing P. aeruginosa infections in CF using a three-dimensional (3D) airway "organ tissue equivalent" (OTE) model. OTEs are fabricated using cells derived from human primary cells sourced from CF donors (CF-OTEs), which accurately recapitulate multiple key traits of human CF airways, including increased mucin accumulation and lower cilium beating frequency, compared to OTEs derived from normal donors (N-OTEs). The OTE model closely approximates the native CF condition to provide a platform where both mucoid and nonmucoid P. aeruginosa establish biofilms. Luminescence quantification and viable bacterial enumeration demonstrated that more P. aeruginosa biofilm mass developed upon CF-OTEs compared to non-CF (normal) OTEs. The capability to establish infection and biofilm formation, without acute tissue toxicity, allows for rapid discrimination of therapeutic efficacy in an accurate, human in vitro model. Farnesol emulsion disrupted P. aeruginosa biofilms in situ and also protected OTE lung cell viability. We propose that the 3D airway OTE infection model is a reliable preclinical tool for CF drug screening, with farnesol emulsion being a prospective drug candidate to treat P. aeruginosa biofilm infections in CF.},
}
RevDate: 2025-10-06
CmpDate: 2025-10-06
The adaptability of Pseudomonas aeruginosa biofilm in oxygen-limited environments.
Frontiers in cellular and infection microbiology, 15:1655335.
Under oxygen-limited conditions, the adaptability and underlying mechanisms of bacterial biofilms have become key areas of interest in microbiology and clinical infection research. Within biofilms-composed of bacterial communities and extracellular matrix-an oxygen gradient commonly forms, resulting in hypoxic or even anoxic microenvironments. Such conditions substantially increase biofilm antibiotic resistance and facilitate the persistence of chronic infections. This review systematically summarizes the adaptive strategies employed by biofilms in hypoxic environments, including anaerobic metabolism, phenazine-mediated electron shuttling, and virulence factor regulation. These adaptive responses are governed by genes involved in anaerobic metabolism, quorum sensing systems, and the secondary messenger 3,5-cyclic diguanylic acid (c-di-GMP), which collectively influence biofilm formation. Key transcriptional regulators such as Anr and Dnr, the two-component system NarXL, along with specific functional genes, form an intricate regulatory network. This article aims to provide a comprehensive overview of the adaptive mechanisms of Pseudomonas aeruginosa biofilms under oxygen-limited conditions, providing a theoretical foundation for the development of novel anti-infective therapies, targeting the biofilm infection microenvironment in cystic fibrosis and chronic wounds.
Additional Links: PMID-41050759
PubMed:
Citation:
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@article {pmid41050759,
year = {2025},
author = {Ren, L and Yuan, Y and Farea, K and Feng, X and He, J and Liu, Y and Zheng, B},
title = {The adaptability of Pseudomonas aeruginosa biofilm in oxygen-limited environments.},
journal = {Frontiers in cellular and infection microbiology},
volume = {15},
number = {},
pages = {1655335},
pmid = {41050759},
issn = {2235-2988},
mesh = {*Biofilms/growth & development ; *Pseudomonas aeruginosa/physiology/genetics/metabolism/drug effects ; *Oxygen/metabolism ; Quorum Sensing ; Gene Expression Regulation, Bacterial ; *Adaptation, Physiological ; Humans ; Anaerobiosis ; Virulence Factors/metabolism ; Cyclic GMP/analogs & derivatives/metabolism ; Phenazines/metabolism ; Pseudomonas Infections/microbiology ; Bacterial Proteins/metabolism/genetics ; },
abstract = {Under oxygen-limited conditions, the adaptability and underlying mechanisms of bacterial biofilms have become key areas of interest in microbiology and clinical infection research. Within biofilms-composed of bacterial communities and extracellular matrix-an oxygen gradient commonly forms, resulting in hypoxic or even anoxic microenvironments. Such conditions substantially increase biofilm antibiotic resistance and facilitate the persistence of chronic infections. This review systematically summarizes the adaptive strategies employed by biofilms in hypoxic environments, including anaerobic metabolism, phenazine-mediated electron shuttling, and virulence factor regulation. These adaptive responses are governed by genes involved in anaerobic metabolism, quorum sensing systems, and the secondary messenger 3,5-cyclic diguanylic acid (c-di-GMP), which collectively influence biofilm formation. Key transcriptional regulators such as Anr and Dnr, the two-component system NarXL, along with specific functional genes, form an intricate regulatory network. This article aims to provide a comprehensive overview of the adaptive mechanisms of Pseudomonas aeruginosa biofilms under oxygen-limited conditions, providing a theoretical foundation for the development of novel anti-infective therapies, targeting the biofilm infection microenvironment in cystic fibrosis and chronic wounds.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Pseudomonas aeruginosa/physiology/genetics/metabolism/drug effects
*Oxygen/metabolism
Quorum Sensing
Gene Expression Regulation, Bacterial
*Adaptation, Physiological
Humans
Anaerobiosis
Virulence Factors/metabolism
Cyclic GMP/analogs & derivatives/metabolism
Phenazines/metabolism
Pseudomonas Infections/microbiology
Bacterial Proteins/metabolism/genetics
RevDate: 2025-10-06
CmpDate: 2025-10-06
Biofilm-based continuous secretion of human lysozyme through cell-surface display of FimH on Saccharomyces cerevisiae.
Synthetic and systems biotechnology, 11:28-36.
Biofilms enhance microbial tolerance to harsh environments while preserving cellular activity over prolonged periods. Although biofilm-based continuous fermentation is widely applied for production of small-molecule chemicals, its application to macromolecular protein production has been rarely reported. Here, FimH, an adhesin from E. coli fimbriae that is employed for mannose-specific adherence and promotes biofilm formation, was displayed on the surface of S. cerevisiae using the anchoring proteins Sag1C, Sed1, Cwp2 and Ccw12, resulting in an 80-150 % enhancement in biofilm formation. Among them, Sed1 was the most effective, followed by Sag1C. A biofilm-based fermentation system for continuous secretion of human lysozyme (hLYZ) was established via cell-surface display of FimH in S. cerevisiae, achieving stable operation for over 350 h. The engineered strain BY4742-Sag1C-hlyz achieved an average extracellular hLYZ activity of 113.1 U/mL, significantly higher than the control BY4742-hlyz (41.6 U/mL), owing to enhanced cell adhesion that increased the total cell number in biofilm-based fermentation. Its productivity reached 2.36 U/mL/h, representing a 77.4 % increase compared with free-cell fermentation of BY4742-hlyz (1.33 U/mL/h). In conclusion, this study first achieved heterologous expression of a bacterial biofilm-forming gene in S. cerevisiae, enhancing biofilm formation and providing a reference for future expression of bacterial biofilm-related genes in yeast. Furthermore, biofilm-based fermentation enabled continuous secretion of hLYZ, highlighting a promising strategy for continuous production of recombinant proteins.
Additional Links: PMID-41050202
PubMed:
Citation:
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@article {pmid41050202,
year = {2026},
author = {Wang, Z and Fu, B and Zhang, H and Li, M and Peng, X and Niu, H and Chen, Y and Zhu, C and Liu, J and Liu, D and Ying, H},
title = {Biofilm-based continuous secretion of human lysozyme through cell-surface display of FimH on Saccharomyces cerevisiae.},
journal = {Synthetic and systems biotechnology},
volume = {11},
number = {},
pages = {28-36},
pmid = {41050202},
issn = {2405-805X},
abstract = {Biofilms enhance microbial tolerance to harsh environments while preserving cellular activity over prolonged periods. Although biofilm-based continuous fermentation is widely applied for production of small-molecule chemicals, its application to macromolecular protein production has been rarely reported. Here, FimH, an adhesin from E. coli fimbriae that is employed for mannose-specific adherence and promotes biofilm formation, was displayed on the surface of S. cerevisiae using the anchoring proteins Sag1C, Sed1, Cwp2 and Ccw12, resulting in an 80-150 % enhancement in biofilm formation. Among them, Sed1 was the most effective, followed by Sag1C. A biofilm-based fermentation system for continuous secretion of human lysozyme (hLYZ) was established via cell-surface display of FimH in S. cerevisiae, achieving stable operation for over 350 h. The engineered strain BY4742-Sag1C-hlyz achieved an average extracellular hLYZ activity of 113.1 U/mL, significantly higher than the control BY4742-hlyz (41.6 U/mL), owing to enhanced cell adhesion that increased the total cell number in biofilm-based fermentation. Its productivity reached 2.36 U/mL/h, representing a 77.4 % increase compared with free-cell fermentation of BY4742-hlyz (1.33 U/mL/h). In conclusion, this study first achieved heterologous expression of a bacterial biofilm-forming gene in S. cerevisiae, enhancing biofilm formation and providing a reference for future expression of bacterial biofilm-related genes in yeast. Furthermore, biofilm-based fermentation enabled continuous secretion of hLYZ, highlighting a promising strategy for continuous production of recombinant proteins.},
}
RevDate: 2025-10-06
CmpDate: 2025-10-06
Sonotheranostic nanosideromycin eradicates bacterial biofilm infections via ultrasound-detonated ROS generation and ferroptosis-like death.
Bioactive materials, 55:241-256.
Biofilm formation poses a severe challenge to antibacterial stewardship. While siderophore-antibiotic conjugates (termed as sideromycins) offer a promising solution, their efficacy is inherently limited by antibiotic resistance. To transcend this barrier, we pioneer a transformative siderophore-sonosensitizer conjugate through covalent linkage of a catechol siderophore to purpurin 18 (a sonosensitizer). This novel conjugate further self-assembles with iron(III) ions, forming the first-reported carrier-free nanosideromycin-an all-in-on iron-siderophore-sonosensitizer nanoplatform. This design enables ultrasound-denotated reactive oxygen species (ROS) generation and ferroptosis-like amplication. Capitalizing on bacteria-specific siderophore uptake and pH-responsive assembly/disassembly, the nanosideromycin enables precision delivery and active internalization of sonosensitizers into bacteria. This strategy permits real-time localization of infections via concurrent fluorescence/photoacoustic and magnetic resonance imaging. Upon ultrasound irradiation, dual antimicrobial mechanisms of sonosensitizer-mediated sonodynamic therapy and siderophore/iron-augmented sono-Fenton catalysis are stimuonously unleashed, synergistically tirggering an explosive ROS burst and potent ferroptosis-like bacterial death. As a result, mice with multidrug-resistant biofilm-induced pyomyositis were completely cured. Collectively, this first-in-class theranostic nanosideromycin integrates highly-targeted imaging diagnostics, cost-effective yet ultra-efficient ROS generation, and ferroptosis-like bacterial killing, establishing a paradigm-shifting strategy for biofilm therapy with spatiotemporal controllability.
Additional Links: PMID-41050139
PubMed:
Citation:
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@article {pmid41050139,
year = {2026},
author = {Pang, X and Zhang, C and Xiao, Q and Cheng, Y and Dai, Q and Chen, H and Tan, S and Liu, G and Zeng, Y},
title = {Sonotheranostic nanosideromycin eradicates bacterial biofilm infections via ultrasound-detonated ROS generation and ferroptosis-like death.},
journal = {Bioactive materials},
volume = {55},
number = {},
pages = {241-256},
pmid = {41050139},
issn = {2452-199X},
abstract = {Biofilm formation poses a severe challenge to antibacterial stewardship. While siderophore-antibiotic conjugates (termed as sideromycins) offer a promising solution, their efficacy is inherently limited by antibiotic resistance. To transcend this barrier, we pioneer a transformative siderophore-sonosensitizer conjugate through covalent linkage of a catechol siderophore to purpurin 18 (a sonosensitizer). This novel conjugate further self-assembles with iron(III) ions, forming the first-reported carrier-free nanosideromycin-an all-in-on iron-siderophore-sonosensitizer nanoplatform. This design enables ultrasound-denotated reactive oxygen species (ROS) generation and ferroptosis-like amplication. Capitalizing on bacteria-specific siderophore uptake and pH-responsive assembly/disassembly, the nanosideromycin enables precision delivery and active internalization of sonosensitizers into bacteria. This strategy permits real-time localization of infections via concurrent fluorescence/photoacoustic and magnetic resonance imaging. Upon ultrasound irradiation, dual antimicrobial mechanisms of sonosensitizer-mediated sonodynamic therapy and siderophore/iron-augmented sono-Fenton catalysis are stimuonously unleashed, synergistically tirggering an explosive ROS burst and potent ferroptosis-like bacterial death. As a result, mice with multidrug-resistant biofilm-induced pyomyositis were completely cured. Collectively, this first-in-class theranostic nanosideromycin integrates highly-targeted imaging diagnostics, cost-effective yet ultra-efficient ROS generation, and ferroptosis-like bacterial killing, establishing a paradigm-shifting strategy for biofilm therapy with spatiotemporal controllability.},
}
RevDate: 2025-10-06
A Comparative Evaluation of Exoenzyme Production, Biofilm Development, and Cell Surface Hydrophobicity in Dominant Genotypes of Candida albicans.
Journal of clinical laboratory analysis [Epub ahead of print].
BACKGROUND: Candida albicans exhibits significant genotypic diversity, and genotypes A and C are the most predominant clinical isolates. The aim of this study was to evaluate the virulence traits of these genotypes, focusing on exoenzyme production, biofilm formation, and cell surface hydrophobicity (CSH) property.
METHODS: A total of 15 genotype A and 15 genotype C clinical C. albicans isolates were evaluated for proteinase, phospholipase, and esterase activities using standard methods. Biofilm formation was quantified using a microtiter plate assay, and CSH was measured using a water-octane two-phase assay.
RESULTS: The study found that Genotype C had higher proteinase and phospholipase activity but no esterase production, while 40% of Genotype A isolates showed strong esterase activity. Biofilm formation and CSH did not differ significantly, though Genotype A trended toward stronger biofilm formation.
CONCLUSION: This study highlights how genotypic variation in C. albicans influences virulence, with Genotype C exhibiting a distinct profile (high proteinase/phospholipase, no esterase) that may enhance pathogenicity, while Genotype A shows adaptability through variable enzyme production and stronger biofilm trends. These differences underscore the need for genotype-specific diagnostics and targeted therapies to improve candidiasis treatment.
Additional Links: PMID-41047914
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PubMed:
Citation:
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@article {pmid41047914,
year = {2025},
author = {Nouraei, H and Amirzadeh, N and Ahmadi, F and Pakshir, K},
title = {A Comparative Evaluation of Exoenzyme Production, Biofilm Development, and Cell Surface Hydrophobicity in Dominant Genotypes of Candida albicans.},
journal = {Journal of clinical laboratory analysis},
volume = {},
number = {},
pages = {e70115},
doi = {10.1002/jcla.70115},
pmid = {41047914},
issn = {1098-2825},
support = {31009//Shiraz University of Medical Sciences/ ; },
abstract = {BACKGROUND: Candida albicans exhibits significant genotypic diversity, and genotypes A and C are the most predominant clinical isolates. The aim of this study was to evaluate the virulence traits of these genotypes, focusing on exoenzyme production, biofilm formation, and cell surface hydrophobicity (CSH) property.
METHODS: A total of 15 genotype A and 15 genotype C clinical C. albicans isolates were evaluated for proteinase, phospholipase, and esterase activities using standard methods. Biofilm formation was quantified using a microtiter plate assay, and CSH was measured using a water-octane two-phase assay.
RESULTS: The study found that Genotype C had higher proteinase and phospholipase activity but no esterase production, while 40% of Genotype A isolates showed strong esterase activity. Biofilm formation and CSH did not differ significantly, though Genotype A trended toward stronger biofilm formation.
CONCLUSION: This study highlights how genotypic variation in C. albicans influences virulence, with Genotype C exhibiting a distinct profile (high proteinase/phospholipase, no esterase) that may enhance pathogenicity, while Genotype A shows adaptability through variable enzyme production and stronger biofilm trends. These differences underscore the need for genotype-specific diagnostics and targeted therapies to improve candidiasis treatment.},
}
RevDate: 2025-10-06
CmpDate: 2025-10-06
In Vivo Efficacy of an Antibiotic Wound Gel in a Sheep Model of Bone Trauma and Biofilm-Related Infection.
Journal of biomedical materials research. Part B, Applied biomaterials, 113(10):e35669.
Traumatic extremity injuries suffer a high probability of infection and often amputation due to contamination and delays in treatment. Military service members are predisposed to injury while engaged in conflict, yet current military adherence to antibiotic administration protocols following traumatic injury is lacking. Moreover, systemic antibiotic prophylaxis might not effectively eradicate biofilm throughout the wound site. Previously, an antibiotic wound gel was created to address current limitations of prophylactic antibiotic treatment in austere environments, particularly the battlefield, by offering a simple solution to control the release of tobramycin over a one-week period. We hypothesized that tobramycin eluted from the gel would effectively manage biofilm-related infection when tested in a large animal model of traumatic long-bone injury. Sheep were either treated with tobramycin-loaded gel or gel alone, and the reduction in bioburden was determined by quantifying tissue and inoculation substrates after a one-week period. Results indicated the wound gel was effective at managing biofilm in this model, with no detectable growth observed in tissues collected from treated animals. Further, the antibiotic-loaded wound gel significantly reduced the severity of the inflammatory response in the surrounding tissue. Biofilm presence was confirmed in scanning electron and light microscopy images of tissues treated with gel alone. Additionally, reactive bone growth, a characteristic of biofilm infection, was consistently observed in all untreated animals but appeared effectively managed in those treated with the antibiotic wound gel. Localized delivery of a broad-spectrum antibiotic from a controlled-release gel can improve adherence to antibiotic administration guidelines and has a greater potential to stabilize biofilm-contaminated wound sites quickly after injury while also mitigating a severe inflammatory response.
Additional Links: PMID-41047754
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PubMed:
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@article {pmid41047754,
year = {2025},
author = {Gilmore, AL and Vu, H and Hylen, KM and Adams, J and Epperson, RT and Kawaguchi, B and Garrett, C and Ashton, NN and Cozzone, E and Florek, CA and Armbruster, DA and Rothberg, DL and Williams, DL},
title = {In Vivo Efficacy of an Antibiotic Wound Gel in a Sheep Model of Bone Trauma and Biofilm-Related Infection.},
journal = {Journal of biomedical materials research. Part B, Applied biomaterials},
volume = {113},
number = {10},
pages = {e35669},
doi = {10.1002/jbm.b.35669},
pmid = {41047754},
issn = {1552-4981},
support = {W81XWH-20-1-0378//Congressionally Directed Medical Research Programs/ ; },
mesh = {Animals ; *Biofilms/drug effects/growth & development ; Sheep ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Tobramycin/pharmacology/chemistry ; Gels ; Disease Models, Animal ; *Wound Infection/drug therapy/microbiology/pathology ; },
abstract = {Traumatic extremity injuries suffer a high probability of infection and often amputation due to contamination and delays in treatment. Military service members are predisposed to injury while engaged in conflict, yet current military adherence to antibiotic administration protocols following traumatic injury is lacking. Moreover, systemic antibiotic prophylaxis might not effectively eradicate biofilm throughout the wound site. Previously, an antibiotic wound gel was created to address current limitations of prophylactic antibiotic treatment in austere environments, particularly the battlefield, by offering a simple solution to control the release of tobramycin over a one-week period. We hypothesized that tobramycin eluted from the gel would effectively manage biofilm-related infection when tested in a large animal model of traumatic long-bone injury. Sheep were either treated with tobramycin-loaded gel or gel alone, and the reduction in bioburden was determined by quantifying tissue and inoculation substrates after a one-week period. Results indicated the wound gel was effective at managing biofilm in this model, with no detectable growth observed in tissues collected from treated animals. Further, the antibiotic-loaded wound gel significantly reduced the severity of the inflammatory response in the surrounding tissue. Biofilm presence was confirmed in scanning electron and light microscopy images of tissues treated with gel alone. Additionally, reactive bone growth, a characteristic of biofilm infection, was consistently observed in all untreated animals but appeared effectively managed in those treated with the antibiotic wound gel. Localized delivery of a broad-spectrum antibiotic from a controlled-release gel can improve adherence to antibiotic administration guidelines and has a greater potential to stabilize biofilm-contaminated wound sites quickly after injury while also mitigating a severe inflammatory response.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Animals
*Biofilms/drug effects/growth & development
Sheep
*Anti-Bacterial Agents/pharmacology/chemistry
*Tobramycin/pharmacology/chemistry
Gels
Disease Models, Animal
*Wound Infection/drug therapy/microbiology/pathology
RevDate: 2025-10-05
Effect of lactoferrin on biofilm formation of bovine mastitis-causing Staphylococcus species.
The Journal of veterinary medical science [Epub ahead of print].
The most common bovine mastitis pathogen is the Staphylococcus species, consisting of Staphylococcus aureus and non-aureus staphylococci (NAS). Lactoferrin (Lf) is an iron-binding protein with antimicrobial and antibiofilm properties. Lf has a metal-free form (apo-Lf) and a natural form (native-Lf), and their differences were reported to affect their activity against bacteria. However, its effects on bovine mastitis-causing Staphylococcus spp. remain unclear. Fifteen S. aureus and 49 NAS strains were isolated from bovine mastitis cases, and their growth and biofilm-forming abilities were observed. Bacterial growth and biofilm formation were observed by culturing each strain with/without bovine milk apo-/native-lactoferrin (200 μg/mL). Without Lf treatment, the growth and biofilm formation abilities of S. aureus were significantly higher and lower, respectively, than those of NAS. The growth of S. aureus and NAS significantly decreased during apo-Lf treatment and significantly reduced the total amount of biofilm produced by S. aureus whereas native-LF treatment did not affect the growth and biofilm formation of Staphylococcus species. These results confirmed the ability of Lf to act as an antimicrobial and antibiofilm substance against mastitis-causing Staphylococcus spp., although various responses from each strain were observed. Additionally, the iron-binding state of Lf affected growth but did not affect the biofilm formation ability. Differences in the responses of Staphylococcus strains to Lf may help explain their pathogenicity, requiring further research.
Additional Links: PMID-41047352
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PubMed:
Citation:
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@article {pmid41047352,
year = {2025},
author = {Seraphina, K and Furukido, R and Isobe, N and Nii, T and Kurokawa, Y and Suzuki, N},
title = {Effect of lactoferrin on biofilm formation of bovine mastitis-causing Staphylococcus species.},
journal = {The Journal of veterinary medical science},
volume = {},
number = {},
pages = {},
doi = {10.1292/jvms.25-0230},
pmid = {41047352},
issn = {1347-7439},
abstract = {The most common bovine mastitis pathogen is the Staphylococcus species, consisting of Staphylococcus aureus and non-aureus staphylococci (NAS). Lactoferrin (Lf) is an iron-binding protein with antimicrobial and antibiofilm properties. Lf has a metal-free form (apo-Lf) and a natural form (native-Lf), and their differences were reported to affect their activity against bacteria. However, its effects on bovine mastitis-causing Staphylococcus spp. remain unclear. Fifteen S. aureus and 49 NAS strains were isolated from bovine mastitis cases, and their growth and biofilm-forming abilities were observed. Bacterial growth and biofilm formation were observed by culturing each strain with/without bovine milk apo-/native-lactoferrin (200 μg/mL). Without Lf treatment, the growth and biofilm formation abilities of S. aureus were significantly higher and lower, respectively, than those of NAS. The growth of S. aureus and NAS significantly decreased during apo-Lf treatment and significantly reduced the total amount of biofilm produced by S. aureus whereas native-LF treatment did not affect the growth and biofilm formation of Staphylococcus species. These results confirmed the ability of Lf to act as an antimicrobial and antibiofilm substance against mastitis-causing Staphylococcus spp., although various responses from each strain were observed. Additionally, the iron-binding state of Lf affected growth but did not affect the biofilm formation ability. Differences in the responses of Staphylococcus strains to Lf may help explain their pathogenicity, requiring further research.},
}
RevDate: 2025-10-05
Nanoplastics induce prophage activation and quorum sensing to enhance biofilm mechanical and chemical resilience.
Water research, 288(Pt B):124712 pii:S0043-1354(25)01615-X [Epub ahead of print].
Despite the prevalence of nanoplastics (NPs) in natural and engineered water systems and their association with microbial risks, bacterium-phage interactions have been largely overlooked in the context of biofilm formation. Here, we investigated the effects of positively (PS-NH2) and negatively (PS-COOH) charged polystyrene nanoplastics (PS-NPs) on dual-species biofilms composed of Escherichia coli (λ+) and Pseudomonas aeruginosa. PS-NPs promoted biofilm formation and stability at environmentally relevant concentrations (e.g., 100-1000 ng/L), with PS-NH2 exhibiting higher influence. The cellular internalization of PS-NPs increased the reactive oxygen species (ROS) levels by 2.18-2.25 folds, triggered prophage λ activation followed by lysis of E. coli (λ+) after exposure to PS-NPs. Transcriptomic analyses revealed that PS-NPs, especially PS-NH2, activated the SOS response (2.35-2.63-fold), λ phage replication (2.68-3.97-fold), and interspecies quorum sensing (2.24-5.13-fold), which was verified by the proteomic analyses. Therefore, PS-NPs stimulated protective extracellular polymeric substances (EPS) secretion with eDNA content increased to 325.8-433.8 μg/cm[2]. Enhanced EPS production contributed to improved biofilm mechanical properties (1.46-1.57-fold as measured by atomic force microscopy) and increased resistance to chlorine disinfection. Metagenomic analysis of pipeline biofilm demonstrated that PS-NPs promoted bacterium-phage interactions and enhanced bacterial antiviral defense systems, which stimulated multi-species biofilm formation and enhanced environmental resilience. Overall, our findings provide novel insights into the interplay between nanoplastics and bacterium-phage dynamics, highlighting increased microbial risks associated with waterborne nanoplastics.
Additional Links: PMID-41046791
Publisher:
PubMed:
Citation:
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@article {pmid41046791,
year = {2025},
author = {Wang, H and Chen, H and Ruan, C and Liao, J and Schwarz, C and Shi, B and Alvarez, PJJ and Yu, P},
title = {Nanoplastics induce prophage activation and quorum sensing to enhance biofilm mechanical and chemical resilience.},
journal = {Water research},
volume = {288},
number = {Pt B},
pages = {124712},
doi = {10.1016/j.watres.2025.124712},
pmid = {41046791},
issn = {1879-2448},
abstract = {Despite the prevalence of nanoplastics (NPs) in natural and engineered water systems and their association with microbial risks, bacterium-phage interactions have been largely overlooked in the context of biofilm formation. Here, we investigated the effects of positively (PS-NH2) and negatively (PS-COOH) charged polystyrene nanoplastics (PS-NPs) on dual-species biofilms composed of Escherichia coli (λ+) and Pseudomonas aeruginosa. PS-NPs promoted biofilm formation and stability at environmentally relevant concentrations (e.g., 100-1000 ng/L), with PS-NH2 exhibiting higher influence. The cellular internalization of PS-NPs increased the reactive oxygen species (ROS) levels by 2.18-2.25 folds, triggered prophage λ activation followed by lysis of E. coli (λ+) after exposure to PS-NPs. Transcriptomic analyses revealed that PS-NPs, especially PS-NH2, activated the SOS response (2.35-2.63-fold), λ phage replication (2.68-3.97-fold), and interspecies quorum sensing (2.24-5.13-fold), which was verified by the proteomic analyses. Therefore, PS-NPs stimulated protective extracellular polymeric substances (EPS) secretion with eDNA content increased to 325.8-433.8 μg/cm[2]. Enhanced EPS production contributed to improved biofilm mechanical properties (1.46-1.57-fold as measured by atomic force microscopy) and increased resistance to chlorine disinfection. Metagenomic analysis of pipeline biofilm demonstrated that PS-NPs promoted bacterium-phage interactions and enhanced bacterial antiviral defense systems, which stimulated multi-species biofilm formation and enhanced environmental resilience. Overall, our findings provide novel insights into the interplay between nanoplastics and bacterium-phage dynamics, highlighting increased microbial risks associated with waterborne nanoplastics.},
}
RevDate: 2025-10-04
Virus Enhanced Microrobots for Biofilm Eradication.
Advanced materials (Deerfield Beach, Fla.) [Epub ahead of print].
Biofilms pose significant challenges in biomedical, industrial, and environmental applications due to their inherent resistance to antimicrobial agents. This study introduced an innovative and effective strategy for biofilm eradication by employing virus-conjugated microrobots (virus@microbots). These biofunctionalized microrobots are synthesized via the hydrothermal method, followed by the functionalization of the viruses. The synergy of microrobots' active movement and the virus's specificity boosted biofilm removal by enabling targeted binding, penetration, and effective delivery into the biofilm matrices. Additionally, compared to microrobots alone, virus@microbots significantly accelerated and refined the process. By integrating biological specificity with magnetic responsiveness, this approach demonstrated the efficacy of virus@microbotsas as a viable antibacterial strategy for biofilm elimination, offering a promising antibacterial platform for combating biofilm-associated infections. Future research should focus on optimizing microrobot design and viral conjugation protocols to enhance scalability and therapeutic specificity, paving the way for clinical translation and broader applications in infection control.
Additional Links: PMID-41045105
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PubMed:
Citation:
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@article {pmid41045105,
year = {2025},
author = {Jyoti, and Arya, S and Peng, X and Pumera, M},
title = {Virus Enhanced Microrobots for Biofilm Eradication.},
journal = {Advanced materials (Deerfield Beach, Fla.)},
volume = {},
number = {},
pages = {e08299},
doi = {10.1002/adma.202508299},
pmid = {41045105},
issn = {1521-4095},
support = {EXPRO: 25-15484X//Czech Republic/ ; CZ.02.01.01/00/22_008/0004587//ERDF/ESF project TECHSCALE/ ; CZ.10.03.01/00/22_003/0000048//European Union under the REFRESH - Research Excellence For REgion Sustainability and High-tech Industries/ ; LM2023050//European Union under the REFRESH - Research Excellence For REgion Sustainability and High-tech Industries/ ; //MEYSCR/ ; },
abstract = {Biofilms pose significant challenges in biomedical, industrial, and environmental applications due to their inherent resistance to antimicrobial agents. This study introduced an innovative and effective strategy for biofilm eradication by employing virus-conjugated microrobots (virus@microbots). These biofunctionalized microrobots are synthesized via the hydrothermal method, followed by the functionalization of the viruses. The synergy of microrobots' active movement and the virus's specificity boosted biofilm removal by enabling targeted binding, penetration, and effective delivery into the biofilm matrices. Additionally, compared to microrobots alone, virus@microbots significantly accelerated and refined the process. By integrating biological specificity with magnetic responsiveness, this approach demonstrated the efficacy of virus@microbotsas as a viable antibacterial strategy for biofilm elimination, offering a promising antibacterial platform for combating biofilm-associated infections. Future research should focus on optimizing microrobot design and viral conjugation protocols to enhance scalability and therapeutic specificity, paving the way for clinical translation and broader applications in infection control.},
}
RevDate: 2025-10-03
CmpDate: 2025-10-04
Impact of hcp and vgrG on Acinetobacter baumannii biofilm formation during infection of human pulmonary alveolar epithelial cells.
Scientific reports, 15(1):34632.
The purpose of this research is to examine the impact of key type VI secretion system (T6SS) proteins hemolysin coregulated protein (Hcp) and valine-glycine repeat protein G (VgrG) on the metabolism of Acinetobacter baumannii (A. baumannii). Homologous recombination technology was used to construct hcp knockout strain (ATCC17978Δhcp), vgrG knockout strain (ATCC17978ΔvgrG), and a combined hcp and vgrG knockout strain (ATCC17978ΔhcpΔvgrG), with the wild-type A. baumannii strain (ATCC17978) used as a control. These strains were co-cultured with human pulmonary alveolar epithelial cells (HPAEpiC), respectively. Subsequently, a non-targeted metabolomic analysis of the co-culture supernatant, bacteria, and cells was conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the bacterial three-pair comparison groups, the major differential metabolites were organic acids and derivatives, as well as organic oxygen compounds (p < 0.05). Further analysis of the major differential metabolites in bacteria revealed five common metabolites with statistically significant differences (p < 0.05), which were N-acetyl-d-glucosamine 6-phosphate, 6-hydroxypseudooxynicotine, 3-deoxy-D-manno-octulosonate, N-Acetylneuraminic acid, and N-acetylmuramoyl-Ala. The annotation of the above five differential metabolites identified five common metabolic pathways with statistically significant differences (p < 0.05). Among these, phosphotransferase system (PTS) showed significant statistical differences (p = 0.01, p = 0.04, p = 0.03) in ATCC17978Δhcp, ATCC17978ΔvgrG, and ATCC17978ΔhcpΔvgrG. The deletion of hcp and the combined deletion of hcp and vgrG led to a downregulation of PTS overall expression, while the deletion of vgrG did not show a significant change in the overall expression level of PTS. The PTS shows a correlation with biofilm formation. The validation experiments demonstrated that ATCC17978Δhcp exhibited significant phenotypic defects, including reduced biofilm formation capacity and visible surface damage under scanning electron microscopy (SEM). In contrast, ATCC17978ΔvgrG maintained wild-type levels of biofilm formation and intact bacterial morphology. Notably, ATCC17978ΔhcpΔvgrG displayed a unique phenotypic reversal, characterized by enhanced biofilm formation, intact bacterial structure, and increased extracellular polymeric substance (EPS) secretion. However, all mutant strains exhibited decreased adhesion ability. The expression levels of biofilm-related genes in each strain showed a positive correlation with their biofilm formation capacity. These results demonstrate that while the PTS influences biofilm formation, it does not serve as the sole regulatory mechanism. The hcp gene plays a crucial role in biofilm formation, whereas the vgrG gene exhibits minimal impact on biofilm formation. Their co-deletion triggers compensatory pathways enhancing biofilm production.
Additional Links: PMID-41044369
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Citation:
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@article {pmid41044369,
year = {2025},
author = {Huang, M and Liu, M and Yang, W and Qin, P and Zhang, Y and Yu, D},
title = {Impact of hcp and vgrG on Acinetobacter baumannii biofilm formation during infection of human pulmonary alveolar epithelial cells.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {34632},
pmid = {41044369},
issn = {2045-2322},
mesh = {Humans ; *Acinetobacter baumannii/physiology/metabolism/genetics ; *Biofilms/growth & development ; *Bacterial Proteins/metabolism/genetics ; *Alveolar Epithelial Cells/microbiology/metabolism ; *Acinetobacter Infections/microbiology/metabolism ; Pulmonary Alveoli/microbiology ; Type VI Secretion Systems/metabolism/genetics ; Tandem Mass Spectrometry ; },
abstract = {The purpose of this research is to examine the impact of key type VI secretion system (T6SS) proteins hemolysin coregulated protein (Hcp) and valine-glycine repeat protein G (VgrG) on the metabolism of Acinetobacter baumannii (A. baumannii). Homologous recombination technology was used to construct hcp knockout strain (ATCC17978Δhcp), vgrG knockout strain (ATCC17978ΔvgrG), and a combined hcp and vgrG knockout strain (ATCC17978ΔhcpΔvgrG), with the wild-type A. baumannii strain (ATCC17978) used as a control. These strains were co-cultured with human pulmonary alveolar epithelial cells (HPAEpiC), respectively. Subsequently, a non-targeted metabolomic analysis of the co-culture supernatant, bacteria, and cells was conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the bacterial three-pair comparison groups, the major differential metabolites were organic acids and derivatives, as well as organic oxygen compounds (p < 0.05). Further analysis of the major differential metabolites in bacteria revealed five common metabolites with statistically significant differences (p < 0.05), which were N-acetyl-d-glucosamine 6-phosphate, 6-hydroxypseudooxynicotine, 3-deoxy-D-manno-octulosonate, N-Acetylneuraminic acid, and N-acetylmuramoyl-Ala. The annotation of the above five differential metabolites identified five common metabolic pathways with statistically significant differences (p < 0.05). Among these, phosphotransferase system (PTS) showed significant statistical differences (p = 0.01, p = 0.04, p = 0.03) in ATCC17978Δhcp, ATCC17978ΔvgrG, and ATCC17978ΔhcpΔvgrG. The deletion of hcp and the combined deletion of hcp and vgrG led to a downregulation of PTS overall expression, while the deletion of vgrG did not show a significant change in the overall expression level of PTS. The PTS shows a correlation with biofilm formation. The validation experiments demonstrated that ATCC17978Δhcp exhibited significant phenotypic defects, including reduced biofilm formation capacity and visible surface damage under scanning electron microscopy (SEM). In contrast, ATCC17978ΔvgrG maintained wild-type levels of biofilm formation and intact bacterial morphology. Notably, ATCC17978ΔhcpΔvgrG displayed a unique phenotypic reversal, characterized by enhanced biofilm formation, intact bacterial structure, and increased extracellular polymeric substance (EPS) secretion. However, all mutant strains exhibited decreased adhesion ability. The expression levels of biofilm-related genes in each strain showed a positive correlation with their biofilm formation capacity. These results demonstrate that while the PTS influences biofilm formation, it does not serve as the sole regulatory mechanism. The hcp gene plays a crucial role in biofilm formation, whereas the vgrG gene exhibits minimal impact on biofilm formation. Their co-deletion triggers compensatory pathways enhancing biofilm production.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Humans
*Acinetobacter baumannii/physiology/metabolism/genetics
*Biofilms/growth & development
*Bacterial Proteins/metabolism/genetics
*Alveolar Epithelial Cells/microbiology/metabolism
*Acinetobacter Infections/microbiology/metabolism
Pulmonary Alveoli/microbiology
Type VI Secretion Systems/metabolism/genetics
Tandem Mass Spectrometry
RevDate: 2025-10-03
Early biofilm colonization on traditional and biodegradable plastics in the Baltic Sea using a mesocosm approach.
Marine environmental research, 212:107592 pii:S0141-1136(25)00649-X [Epub ahead of print].
Bioplastics are promising alternatives to conventional plastics, but their potential entry into marine ecosystems highlights the need for a better understanding of their interactions with microbial communities, including their role in the plastisphere. Here, we characterized the early biofilm formation on traditional plastics and bioplastics using a mesocosm approach. We tested the hypothesis that distinct bacterial communities selectively colonize traditional and biodegradable plastics in the marine environment. Specifically, fragments of the petroleum-based plastic polypropylene (PP) and the bioplastics Poly(3-hydroxybutyrate)- hydroxyvalerate (PHBv) and polylactic acid (PLA) were submerged in Baltic Sea mesocosms for three weeks. Biofilm colonization, prokaryotic abundance, and community composition were assessed through scanning electronic microscopy analysis, epifluorescence microscopy and 16S rRNA gene metabarcoding, respectively. Biofilm development increased over time on both traditional and bioplastics, with photosynthetic organisms appearing after 3 weeks. However, prokaryotic abundance decreased over time except on PLA surfaces. Prokaryotic communities' composition differed among biofilms formed on the different polymers. The microbial community associated with conventional plastic PP was more similar to that of the seawater in the control treatment, while biofilms on PLA and PHBv shared a higher degree of similarity with each other. These findings suggest that microbial communities selectively colonize different plastic types, with bioplastics supporting distinct and specific bacterial biofilm assemblages over three-week exposure. The great diversity observed in bioplastics, particularly PLA, suggests they may support more complex and potentially active plastisphere communities after only three weeks of exposure to the Baltic Sea.
Additional Links: PMID-41043260
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@article {pmid41043260,
year = {2025},
author = {Gambardella, C and Basili, M and Castelli, F and Miroglio, R and Manini, E and Quero, GM and Almeda, R and Regoli, F and Faimali, M and Garaventa, F},
title = {Early biofilm colonization on traditional and biodegradable plastics in the Baltic Sea using a mesocosm approach.},
journal = {Marine environmental research},
volume = {212},
number = {},
pages = {107592},
doi = {10.1016/j.marenvres.2025.107592},
pmid = {41043260},
issn = {1879-0291},
abstract = {Bioplastics are promising alternatives to conventional plastics, but their potential entry into marine ecosystems highlights the need for a better understanding of their interactions with microbial communities, including their role in the plastisphere. Here, we characterized the early biofilm formation on traditional plastics and bioplastics using a mesocosm approach. We tested the hypothesis that distinct bacterial communities selectively colonize traditional and biodegradable plastics in the marine environment. Specifically, fragments of the petroleum-based plastic polypropylene (PP) and the bioplastics Poly(3-hydroxybutyrate)- hydroxyvalerate (PHBv) and polylactic acid (PLA) were submerged in Baltic Sea mesocosms for three weeks. Biofilm colonization, prokaryotic abundance, and community composition were assessed through scanning electronic microscopy analysis, epifluorescence microscopy and 16S rRNA gene metabarcoding, respectively. Biofilm development increased over time on both traditional and bioplastics, with photosynthetic organisms appearing after 3 weeks. However, prokaryotic abundance decreased over time except on PLA surfaces. Prokaryotic communities' composition differed among biofilms formed on the different polymers. The microbial community associated with conventional plastic PP was more similar to that of the seawater in the control treatment, while biofilms on PLA and PHBv shared a higher degree of similarity with each other. These findings suggest that microbial communities selectively colonize different plastic types, with bioplastics supporting distinct and specific bacterial biofilm assemblages over three-week exposure. The great diversity observed in bioplastics, particularly PLA, suggests they may support more complex and potentially active plastisphere communities after only three weeks of exposure to the Baltic Sea.},
}
RevDate: 2025-10-03
CmpDate: 2025-10-03
Antibacterial, anti-biofilm and anti-virulence activity of biosynthesized silver nanoparticles against drug-resistant Staphylococcus aureus.
Veterinary research communications, 49(6):345.
Antibiotic resistance in bacteria has become a major concern for the effective treatment of infections; therefore, alternatives to antibiotics are being extensively researched to combat drug-resistant microbes. In this study, silver nanoparticles (AgNPs) were biosynthesized using aqueous extracts of papaya leaves (Carica papaya), cannabis leaves (Cannabis sativa), and cardamom (Elettaria cardamomum) and characterized by field-emission scanning electron microscopy (FE-SEM) and UV-visible spectrophotometry. Biosynthesized AgNPs were evaluated for their antibacterial, anti-biofilm, and anti-virulence potential by phenotypic and genotypic methods. AgNPs biosynthesized by all three extracts had spherical morphology and sizes in the nanoscale, average diameter ranging from 46.05 to 94.12 nm. Antibacterial susceptibility testing of S. aureus field isolates under study revealed 48% (24/50) and 38% (19/50) to be resistant to methicillin and amoxycillin-clavulanic acid, respectively. Antibacterial activity of biosynthesized AgNPs against S. aureus strains was determined by the well diffusion method. AgNPs were found to be effective on 90.90% (50/55) S. aureus strains with a zone of inhibition varying from 10 to 21 mm. The AgNPs were also found to be effective on other important bacterial pathogens (viz. Bacillus cereus ATCC 10876, Pseudomonas aeruginosa ATCC 27853, Salmonella Enteritidis ATCC 13070, Escherichia coli ATCC 43888, and Listeria monocytogenes MTCC 657) screened in the study with a ZOI of 15-18 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs against S. aureus ranged between 0.015625-0.125 mg/mL and 0.015625-0.25 mg/mL, respectively. In the time kill assay, AgNPs were able to kill S. aureus rapidly within 0.5-1.0 h. In the haemolytic assay, 4-9% haemolysis was observed at concentrations ranging from 0.015625 to 0.25 mg/mL of AgNPs. Biofilm-forming ability of all strains of S. aureus (n = 55) determined by crystal violet assay revealed that 87.27% (48/55) were biofilm formers, while 12.73% (7/55) were non-biofilm formers. Out of 48 biofilm-forming strains, 81.25% (39/48) were strong biofilm producers, 10.41% (5/48) were moderate biofilm producers, and 8.33% (4/48) were weak biofilm producers. Anti-biofilm effect of AgNPs was found at sub-MIC (0.03125 mg/mL), phenotypically. Exopolysaccharide production was found to be reduced by 53.38% indicating the anti-virulence potential of AgNPs at sub-MIC. Relative expression analysis revealed that AgNPs downregulated the expression of biofilm-related genes, namely icaC, icaD, and spa, by 14.2, 10.6, and 8.7-fold, respectively, compared to the control at 3 h of incubation. Other biofilm-related and virulence genes, including icaA, icaB, icaR, agr, ebps, fnb-B, sar-A, and katA, were also found to be downregulated by 7.4, 7.5, 6.2, 5, 4.2, 7.3, 4, and 3.6-fold, respectively, at 3 h. All the target genes were also found to be downregulated at 24 h post-treatment with AgNPs, except icaD, icaR, and agr, which were slightly upregulated. In the present study, AgNPs were successfully biosynthesized and found to possess broad-spectrum antibacterial activity, reduce biofilm formation, and EPS production. Biosynthesized AgNPs has potential to be utilized as antibacterial, anti-biofilm, and anti-virulence agents against S. aureus, as alternative to conventional antibacterial agents.
Additional Links: PMID-41042408
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@article {pmid41042408,
year = {2025},
author = {Singh, J and Agrawal, RK and Bankoti, K and Sarkar, R and Saini, M and Kashyap, K and Kumar, D and Sharma, GK and Jha, PN and Jain, S and Singh, BR},
title = {Antibacterial, anti-biofilm and anti-virulence activity of biosynthesized silver nanoparticles against drug-resistant Staphylococcus aureus.},
journal = {Veterinary research communications},
volume = {49},
number = {6},
pages = {345},
pmid = {41042408},
issn = {1573-7446},
support = {CRG/2021/003683/BHS//Department of Science and Technology, Ministry of Science and Technology, India/ ; NAHEP CAAST-ACLH//Indian Council of Agricultural Research/ ; },
mesh = {*Silver/pharmacology/chemistry ; *Biofilms/drug effects ; *Metal Nanoparticles/chemistry ; *Anti-Bacterial Agents/pharmacology ; Plant Extracts/chemistry/pharmacology ; Microbial Sensitivity Tests ; *Staphylococcus aureus/drug effects/physiology/pathogenicity ; Virulence/drug effects ; Plant Leaves/chemistry ; },
abstract = {Antibiotic resistance in bacteria has become a major concern for the effective treatment of infections; therefore, alternatives to antibiotics are being extensively researched to combat drug-resistant microbes. In this study, silver nanoparticles (AgNPs) were biosynthesized using aqueous extracts of papaya leaves (Carica papaya), cannabis leaves (Cannabis sativa), and cardamom (Elettaria cardamomum) and characterized by field-emission scanning electron microscopy (FE-SEM) and UV-visible spectrophotometry. Biosynthesized AgNPs were evaluated for their antibacterial, anti-biofilm, and anti-virulence potential by phenotypic and genotypic methods. AgNPs biosynthesized by all three extracts had spherical morphology and sizes in the nanoscale, average diameter ranging from 46.05 to 94.12 nm. Antibacterial susceptibility testing of S. aureus field isolates under study revealed 48% (24/50) and 38% (19/50) to be resistant to methicillin and amoxycillin-clavulanic acid, respectively. Antibacterial activity of biosynthesized AgNPs against S. aureus strains was determined by the well diffusion method. AgNPs were found to be effective on 90.90% (50/55) S. aureus strains with a zone of inhibition varying from 10 to 21 mm. The AgNPs were also found to be effective on other important bacterial pathogens (viz. Bacillus cereus ATCC 10876, Pseudomonas aeruginosa ATCC 27853, Salmonella Enteritidis ATCC 13070, Escherichia coli ATCC 43888, and Listeria monocytogenes MTCC 657) screened in the study with a ZOI of 15-18 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs against S. aureus ranged between 0.015625-0.125 mg/mL and 0.015625-0.25 mg/mL, respectively. In the time kill assay, AgNPs were able to kill S. aureus rapidly within 0.5-1.0 h. In the haemolytic assay, 4-9% haemolysis was observed at concentrations ranging from 0.015625 to 0.25 mg/mL of AgNPs. Biofilm-forming ability of all strains of S. aureus (n = 55) determined by crystal violet assay revealed that 87.27% (48/55) were biofilm formers, while 12.73% (7/55) were non-biofilm formers. Out of 48 biofilm-forming strains, 81.25% (39/48) were strong biofilm producers, 10.41% (5/48) were moderate biofilm producers, and 8.33% (4/48) were weak biofilm producers. Anti-biofilm effect of AgNPs was found at sub-MIC (0.03125 mg/mL), phenotypically. Exopolysaccharide production was found to be reduced by 53.38% indicating the anti-virulence potential of AgNPs at sub-MIC. Relative expression analysis revealed that AgNPs downregulated the expression of biofilm-related genes, namely icaC, icaD, and spa, by 14.2, 10.6, and 8.7-fold, respectively, compared to the control at 3 h of incubation. Other biofilm-related and virulence genes, including icaA, icaB, icaR, agr, ebps, fnb-B, sar-A, and katA, were also found to be downregulated by 7.4, 7.5, 6.2, 5, 4.2, 7.3, 4, and 3.6-fold, respectively, at 3 h. All the target genes were also found to be downregulated at 24 h post-treatment with AgNPs, except icaD, icaR, and agr, which were slightly upregulated. In the present study, AgNPs were successfully biosynthesized and found to possess broad-spectrum antibacterial activity, reduce biofilm formation, and EPS production. Biosynthesized AgNPs has potential to be utilized as antibacterial, anti-biofilm, and anti-virulence agents against S. aureus, as alternative to conventional antibacterial agents.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Silver/pharmacology/chemistry
*Biofilms/drug effects
*Metal Nanoparticles/chemistry
*Anti-Bacterial Agents/pharmacology
Plant Extracts/chemistry/pharmacology
Microbial Sensitivity Tests
*Staphylococcus aureus/drug effects/physiology/pathogenicity
Virulence/drug effects
Plant Leaves/chemistry
RevDate: 2025-10-03
CmpDate: 2025-10-03
Antibiotic resistance and biofilm formation in Klebsiella pneumoniae: A global health threat.
Journal of family medicine and primary care, 14(8):3610-3611.
Additional Links: PMID-41041227
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@article {pmid41041227,
year = {2025},
author = {Sahai, S and Das, NK},
title = {Antibiotic resistance and biofilm formation in Klebsiella pneumoniae: A global health threat.},
journal = {Journal of family medicine and primary care},
volume = {14},
number = {8},
pages = {3610-3611},
pmid = {41041227},
issn = {2249-4863},
}
RevDate: 2025-10-03
CmpDate: 2025-10-03
Biofilm-disrupting heterojunction microneedles: dual ROS amplification and glucose deprivation for accelerated diabetic wound healing.
Theranostics, 15(18):9757-9774.
Rationale: Diabetic wound healing process is critically hindered by bacterial infection, bacterial biofilm formation, and persistent hyperglycemia. Biomolecular microneedles represent a promising alternative to conventional therapies such as antibiotics and antibiotic-loaded wound dressings, owing to the advantages like reduced risk of drug resistance and enhanced long-term efficacy. However, the microneedles that fulfill the clinical needs of diabetic wounds have rarely been reported. Methods: A glucose oxidase (GOx)-laden Ti3C2/In2O3 (INTG) heterojunction was engineered as a nano-micro platform for reactive oxygen species (ROS) amplification and glucose deprivation, and subsequently immobilized onto the gelatin methacryloyl (GelMA) microneedle tips to obtain double-layer microneedles (GITG microneedles). Their physiochemical properties and biomedical applications were comprehensively investigated. Results: For INTG heterojunction, the formation of Schottky structure significantly improved the oxygen absorption capacity, facilitated the generation and migration of photogenerated electron-hole pairs, thereby promoting the ROS generation. Besides, under near-infrared (NIR) irradiation, GITG microneedles effectively inhibited bacterial proliferation and survival by generating ROS, thereby preventing the formation of bacterial biofilm. Additionally, GITG microneedles accelerated wound closure and facilitated skin tissue regeneration in a rat model through multiple mechanisms. Conclusion: This study developed an advanced microneedle platform enabling on-demand multimodal treatment, demonstrating significant potential for clinical diabetic wound management.
Additional Links: PMID-41041072
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Citation:
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@article {pmid41041072,
year = {2025},
author = {You, W and Xiao, F and Cai, Z and Zhao, J and Zhang, Z and Hu, W and Chen, Y and Choy, KL and Wang, Z},
title = {Biofilm-disrupting heterojunction microneedles: dual ROS amplification and glucose deprivation for accelerated diabetic wound healing.},
journal = {Theranostics},
volume = {15},
number = {18},
pages = {9757-9774},
pmid = {41041072},
issn = {1838-7640},
mesh = {Animals ; *Biofilms/drug effects/growth & development ; *Wound Healing/drug effects ; *Reactive Oxygen Species/metabolism ; Rats ; Glucose Oxidase/metabolism ; *Needles ; *Glucose/metabolism ; Diabetes Mellitus, Experimental/complications ; Male ; Rats, Sprague-Dawley ; Anti-Bacterial Agents ; },
abstract = {Rationale: Diabetic wound healing process is critically hindered by bacterial infection, bacterial biofilm formation, and persistent hyperglycemia. Biomolecular microneedles represent a promising alternative to conventional therapies such as antibiotics and antibiotic-loaded wound dressings, owing to the advantages like reduced risk of drug resistance and enhanced long-term efficacy. However, the microneedles that fulfill the clinical needs of diabetic wounds have rarely been reported. Methods: A glucose oxidase (GOx)-laden Ti3C2/In2O3 (INTG) heterojunction was engineered as a nano-micro platform for reactive oxygen species (ROS) amplification and glucose deprivation, and subsequently immobilized onto the gelatin methacryloyl (GelMA) microneedle tips to obtain double-layer microneedles (GITG microneedles). Their physiochemical properties and biomedical applications were comprehensively investigated. Results: For INTG heterojunction, the formation of Schottky structure significantly improved the oxygen absorption capacity, facilitated the generation and migration of photogenerated electron-hole pairs, thereby promoting the ROS generation. Besides, under near-infrared (NIR) irradiation, GITG microneedles effectively inhibited bacterial proliferation and survival by generating ROS, thereby preventing the formation of bacterial biofilm. Additionally, GITG microneedles accelerated wound closure and facilitated skin tissue regeneration in a rat model through multiple mechanisms. Conclusion: This study developed an advanced microneedle platform enabling on-demand multimodal treatment, demonstrating significant potential for clinical diabetic wound management.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Animals
*Biofilms/drug effects/growth & development
*Wound Healing/drug effects
*Reactive Oxygen Species/metabolism
Rats
Glucose Oxidase/metabolism
*Needles
*Glucose/metabolism
Diabetes Mellitus, Experimental/complications
Male
Rats, Sprague-Dawley
Anti-Bacterial Agents
RevDate: 2025-10-03
CmpDate: 2025-10-03
From biofilm control to biomimetic remineralization: Hydrogels in prevention and treatment of dental caries.
Frontiers in cellular and infection microbiology, 15:1663563.
Dental caries, a prevalent chronic bacterial disease globally, poses a significant threat to public health due to its complex pathogenesis involving demineralization and microbial dysbiosis. Hydrogels, with their unique three-dimensional network structures and diverse properties, have shown great potential in prevention and treatment of dental caries. This article systematically reviews recent advances in anti-caries hydrogel development. It first introduces the basis of anti-caries hydrogels, covering the applications of natural and semi-synthetic polymers as hydrogel matrices. Then, it elaborates on the mechanisms and research status of different types of anti-caries hydrogels, including probiotic formulations, antibacterial hydrogels, remineralization-inducing hydrogels, and saliva-related caries-reducing hydrogels. Finally, it summarizes the current research achievements and limitations and looks ahead to future research directions.
Additional Links: PMID-41040988
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Citation:
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@article {pmid41040988,
year = {2025},
author = {Chen, Y and Lin, S and Huang, X and Zhou, W},
title = {From biofilm control to biomimetic remineralization: Hydrogels in prevention and treatment of dental caries.},
journal = {Frontiers in cellular and infection microbiology},
volume = {15},
number = {},
pages = {1663563},
pmid = {41040988},
issn = {2235-2988},
mesh = {*Hydrogels/therapeutic use/chemistry/pharmacology ; *Dental Caries/prevention & control/microbiology/therapy/drug therapy ; *Biofilms/drug effects/growth & development ; Humans ; Anti-Bacterial Agents/therapeutic use/pharmacology ; Probiotics/therapeutic use ; Saliva/microbiology ; Biomimetics/methods ; Tooth Remineralization/methods ; Biomineralization ; },
abstract = {Dental caries, a prevalent chronic bacterial disease globally, poses a significant threat to public health due to its complex pathogenesis involving demineralization and microbial dysbiosis. Hydrogels, with their unique three-dimensional network structures and diverse properties, have shown great potential in prevention and treatment of dental caries. This article systematically reviews recent advances in anti-caries hydrogel development. It first introduces the basis of anti-caries hydrogels, covering the applications of natural and semi-synthetic polymers as hydrogel matrices. Then, it elaborates on the mechanisms and research status of different types of anti-caries hydrogels, including probiotic formulations, antibacterial hydrogels, remineralization-inducing hydrogels, and saliva-related caries-reducing hydrogels. Finally, it summarizes the current research achievements and limitations and looks ahead to future research directions.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Hydrogels/therapeutic use/chemistry/pharmacology
*Dental Caries/prevention & control/microbiology/therapy/drug therapy
*Biofilms/drug effects/growth & development
Humans
Anti-Bacterial Agents/therapeutic use/pharmacology
Probiotics/therapeutic use
Saliva/microbiology
Biomimetics/methods
Tooth Remineralization/methods
Biomineralization
RevDate: 2025-10-03
CmpDate: 2025-10-03
Mechanisms of antibiofilm compounds JG-1 and M4 across multiple species: alterations of protein interactions essential to biofilm formation.
Frontiers in cellular and infection microbiology, 15:1631575.
The majority of human bacterial pathogens have the ability to form biofilms in vivo on body tissues and implantable medical devices. Biofilm-mediated chronic bacterial infections are difficult to treat due to their recalcitrance to antimicrobials and immune effectors, often requiring invasive surgical intervention to clear the infection. The difficulty in effectively executing these treatment strategies underscores the need for therapeutic agents that specifically target the biofilm state. To this end, we previously identified two small molecules, JG-1 and M4, that in vitro effectively inhibit and disperse biofilms of Salmonella Typhimurium and members of the ESKAPE pathogen group, including Enterobacter cloacae, Pseudomonas aeruginosa, and Acinetobacter baumannii. In addition to its antibiofilm effects, M4 has a bactericidal effect on Staphylococcus aureus and Enterococcus faecium. While these compounds have promising utility as antimicrobial agents, their mechanism of action remains unknown. By employing multiple techniques including RNAseq, thermal proteome profiling, and site directed mutagenesis, we identified multiple proteins essential to biofilm formation and evaluated their role in the presence of JG-1 and M4 in mutant and wildtype backgrounds. We report that the JG-1 and M4 actions are influenced by proteins important to biofilm maintenance, including OmpA, OmpC, and TrxA. Compound-bacteria interactions cause transcriptional changes that result in biofilm dispersal, and modulation of other virulence mechanisms, including invasion and motility. Additionally, we report that M4 interacts with S. aureus CodY, which promotes cell death, while the specific targets in S. Typhimurium and E. cloacae remain elusive. Collectively, this study presents an empirical investigation into JG-1 and M4's mechanism of action in S. Typhimurium, E. cloacae, and S. aureus, and how the antibiofilm compounds disrupt microbial community dynamics, ultimately driving biofilm dispersal or cell death.
Additional Links: PMID-41040982
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@article {pmid41040982,
year = {2025},
author = {Bennett, AN and Maziarz, JF and Laipply, B and Cole, AL and Woolard, KJ and Sorge, A and Zeiler, MJ and Melander, RJ and Melander, C and Gunn, JS},
title = {Mechanisms of antibiofilm compounds JG-1 and M4 across multiple species: alterations of protein interactions essential to biofilm formation.},
journal = {Frontiers in cellular and infection microbiology},
volume = {15},
number = {},
pages = {1631575},
pmid = {41040982},
issn = {2235-2988},
mesh = {*Biofilms/drug effects/growth & development ; *Anti-Bacterial Agents/pharmacology ; *Bacterial Proteins/metabolism/genetics ; Enterobacter cloacae/drug effects/physiology ; Pseudomonas aeruginosa/drug effects ; Salmonella typhimurium/drug effects/physiology ; Acinetobacter baumannii/drug effects ; Staphylococcus aureus/drug effects ; Humans ; Microbial Sensitivity Tests ; Enterococcus faecium/drug effects ; },
abstract = {The majority of human bacterial pathogens have the ability to form biofilms in vivo on body tissues and implantable medical devices. Biofilm-mediated chronic bacterial infections are difficult to treat due to their recalcitrance to antimicrobials and immune effectors, often requiring invasive surgical intervention to clear the infection. The difficulty in effectively executing these treatment strategies underscores the need for therapeutic agents that specifically target the biofilm state. To this end, we previously identified two small molecules, JG-1 and M4, that in vitro effectively inhibit and disperse biofilms of Salmonella Typhimurium and members of the ESKAPE pathogen group, including Enterobacter cloacae, Pseudomonas aeruginosa, and Acinetobacter baumannii. In addition to its antibiofilm effects, M4 has a bactericidal effect on Staphylococcus aureus and Enterococcus faecium. While these compounds have promising utility as antimicrobial agents, their mechanism of action remains unknown. By employing multiple techniques including RNAseq, thermal proteome profiling, and site directed mutagenesis, we identified multiple proteins essential to biofilm formation and evaluated their role in the presence of JG-1 and M4 in mutant and wildtype backgrounds. We report that the JG-1 and M4 actions are influenced by proteins important to biofilm maintenance, including OmpA, OmpC, and TrxA. Compound-bacteria interactions cause transcriptional changes that result in biofilm dispersal, and modulation of other virulence mechanisms, including invasion and motility. Additionally, we report that M4 interacts with S. aureus CodY, which promotes cell death, while the specific targets in S. Typhimurium and E. cloacae remain elusive. Collectively, this study presents an empirical investigation into JG-1 and M4's mechanism of action in S. Typhimurium, E. cloacae, and S. aureus, and how the antibiofilm compounds disrupt microbial community dynamics, ultimately driving biofilm dispersal or cell death.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Anti-Bacterial Agents/pharmacology
*Bacterial Proteins/metabolism/genetics
Enterobacter cloacae/drug effects/physiology
Pseudomonas aeruginosa/drug effects
Salmonella typhimurium/drug effects/physiology
Acinetobacter baumannii/drug effects
Staphylococcus aureus/drug effects
Humans
Microbial Sensitivity Tests
Enterococcus faecium/drug effects
RevDate: 2025-10-03
CmpDate: 2025-10-03
Pseudomonas aeruginosa uses kinases NahK and RetS to control the motile-biofilm switch.
bioRxiv : the preprint server for biology pii:2025.09.24.678285.
The multidrug-resistant bacterium Pseudomonas aeruginosa (Pa) poses a significant threat to public health. This Gram-negative bacterium establishes pathogenicity through formation of multicellular communities, known as biofilms, that result in significant resistance to antibiotics and host immune systems. In Pa , the motile-to-biofilm transition is regulated through an interconnected signaling network known as the Gac Multikinase Network (Gac-MKN). This network comprises two regulatory branches: the HptB signaling network and GacS/A signaling network. In the Gac-MKN, several histidine kinases converge to regulate the activity of the post-transcriptional regulator protein, RsmA. Although previous studies have assessed the role of individual kinases in this network, the role of each Gac-MKN kinase in regulating RsmA activity has not been quantitatively characterized and compared in side-by-side experiments in the same reference strain, which is presented here. In this study, we show that kinases NahK and RetS are the predominant regulators of the Gac-MKN. Through controlled testing of RsmA-dependent phenotypes, we demonstrate loss of nahK or retS leads to complete inactivation of RsmA, triggering biofilm formation. Our results support previous findings that RetS regulates RsmA through the GacS/A network but present the new finding that NahK is the central kinase involved in HptB phosphorylation; previous studies have attributed HptB phosphorylation to PA1611 and SagS. Our findings demonstrate that NahK signaling controls RsmA activity to rapidly transition between the motile and biofilm states. We anticipate the results of this study will facilitate the use of targeting the Gac-MKN to trigger biofilm dispersal for improved antibiotic treatment.
Additional Links: PMID-41040157
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@article {pmid41040157,
year = {2025},
author = {Withorn, JM and Ramcharan, K and Alfano, NE and Mendoza, AG and Fu, J and Guercio, D and MacDermott, A and Byrne, KE and Boon, EM},
title = {Pseudomonas aeruginosa uses kinases NahK and RetS to control the motile-biofilm switch.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2025.09.24.678285},
pmid = {41040157},
issn = {2692-8205},
abstract = {The multidrug-resistant bacterium Pseudomonas aeruginosa (Pa) poses a significant threat to public health. This Gram-negative bacterium establishes pathogenicity through formation of multicellular communities, known as biofilms, that result in significant resistance to antibiotics and host immune systems. In Pa , the motile-to-biofilm transition is regulated through an interconnected signaling network known as the Gac Multikinase Network (Gac-MKN). This network comprises two regulatory branches: the HptB signaling network and GacS/A signaling network. In the Gac-MKN, several histidine kinases converge to regulate the activity of the post-transcriptional regulator protein, RsmA. Although previous studies have assessed the role of individual kinases in this network, the role of each Gac-MKN kinase in regulating RsmA activity has not been quantitatively characterized and compared in side-by-side experiments in the same reference strain, which is presented here. In this study, we show that kinases NahK and RetS are the predominant regulators of the Gac-MKN. Through controlled testing of RsmA-dependent phenotypes, we demonstrate loss of nahK or retS leads to complete inactivation of RsmA, triggering biofilm formation. Our results support previous findings that RetS regulates RsmA through the GacS/A network but present the new finding that NahK is the central kinase involved in HptB phosphorylation; previous studies have attributed HptB phosphorylation to PA1611 and SagS. Our findings demonstrate that NahK signaling controls RsmA activity to rapidly transition between the motile and biofilm states. We anticipate the results of this study will facilitate the use of targeting the Gac-MKN to trigger biofilm dispersal for improved antibiotic treatment.},
}
RevDate: 2025-10-03
Identification of ShgH as a dual histidine/glutamine transporter component essential for Streptococcus suis virulence and biofilm modulation.
Microbiological research, 302:128354 pii:S0944-5013(25)00313-1 [Epub ahead of print].
Streptococcus suis is a zoonotic pathogen that affects pigs and humans. In this study, we characterised ShgH, a predicted substrate-binding component of an ABC transporter. Immunoassays confirmed that ShgH is expressed, secreted and surface-exposed in S. suis, in agreement with its proposed transporter function. Isothermal titration calorimetry demonstrated that ShgH binds glutamine and histidine, with a higher affinity for histidine. Deletion of the shgH gene significantly impaired uptake of both radiolabelled amino acids confirming its role as part of a transporter. Functional analysis revealed that shgH deletion results in a marked reduction in virulence in a murine infection model, while host colonization remained unaffected. ShgH contributes to infection by facilitating evasion of phagocytosis and resistance to oxidative stress through impaired nutrient acquisition and reduced capsule production. In addition, ShgH regulates biofilm formation and architecture. Notably, ShgH is highly conserved among pathogenic streptococci, suggesting a broader functional relevance. Altogether, our findings identify ShgH as a dual glutamine/histidine- binding protein essential for nutrient uptake and virulence in S. suis, and a promising target for future therapeutic interventions.
Additional Links: PMID-41039685
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@article {pmid41039685,
year = {2025},
author = {García, C and Saralegui, L and Morales, B and Jurado, P and Bes, MT and Marín, C and Arenas, J},
title = {Identification of ShgH as a dual histidine/glutamine transporter component essential for Streptococcus suis virulence and biofilm modulation.},
journal = {Microbiological research},
volume = {302},
number = {},
pages = {128354},
doi = {10.1016/j.micres.2025.128354},
pmid = {41039685},
issn = {1618-0623},
abstract = {Streptococcus suis is a zoonotic pathogen that affects pigs and humans. In this study, we characterised ShgH, a predicted substrate-binding component of an ABC transporter. Immunoassays confirmed that ShgH is expressed, secreted and surface-exposed in S. suis, in agreement with its proposed transporter function. Isothermal titration calorimetry demonstrated that ShgH binds glutamine and histidine, with a higher affinity for histidine. Deletion of the shgH gene significantly impaired uptake of both radiolabelled amino acids confirming its role as part of a transporter. Functional analysis revealed that shgH deletion results in a marked reduction in virulence in a murine infection model, while host colonization remained unaffected. ShgH contributes to infection by facilitating evasion of phagocytosis and resistance to oxidative stress through impaired nutrient acquisition and reduced capsule production. In addition, ShgH regulates biofilm formation and architecture. Notably, ShgH is highly conserved among pathogenic streptococci, suggesting a broader functional relevance. Altogether, our findings identify ShgH as a dual glutamine/histidine- binding protein essential for nutrient uptake and virulence in S. suis, and a promising target for future therapeutic interventions.},
}
RevDate: 2025-10-02
CmpDate: 2025-10-03
Urinary tract infection due to Staphylococcus schleiferi biofilm formation in the subcutaneous ureteral bypass system in a cat.
BMC veterinary research, 21(1):566.
BACKGROUND: Staphylococcus schleiferi is mainly isolated from dogs and occasionally infects cats. We recently encountered a case of a biofilm-related urinary tract infection (UTI) caused by S. schleiferi in a cat with a subcutaneous ureteral bypass (SUB) system. This report presents a case of biofilm formation by S. schleiferi in the SUB system and discusses the causes of UTIs.
CASE PRESENTATION: A 9-year-old female cat had been using the SUB system since 4 years-of-age. The cat had no significant clinical history or UTIs for 4 years after the first implantation of the SUB system. The SUB system was flushed once per month. When the cat was 8 years-of-age, the subcutaneous port of the SUB system was contaminated with Staphylococcus pseudintermedius and replaced with a new one. Subsequently, the SUB system had no particular problem for 8 months. The SUB system was flushed once every 2 months. However, the cat occasionally developed gross haematuria. Additionally, S. schleiferi was detected in urine. Although doxycycline was administered to the cat, 6 weeks later, the cat had cutaneous wounds with abscesses caused by excessive grooming of the skin in contact with the subcutaneous port of the SUB system. S. schleiferi was detected in a severe abscess in the cutaneous wound, and skin necrosis was observed. As bacterial contamination of the SUB system was suspected, the SUB system was removed from the cat. Scanning electron microscopy analysis revealed biofilm formation inside the locking loop catheters and outside the subcutaneous port of the SUB system. In an in vitro assay, S. schleiferi isolated from a catheter of the SUB system had low biofilm-forming ability. After the SUB system was removed, S. schleiferi was not detected in the urine and the infection was completely cured.
CONCLUSION: Considering these results, bacterial infections in cats with SUB systems should be carefully monitored, as contamination by biofilm-forming bacteria can occur regardless of flushing frequency.
Additional Links: PMID-41039565
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Citation:
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@article {pmid41039565,
year = {2025},
author = {Sato, Y and Hatayama, N and Suzuki, Y and Yugeta, N and Yoshino, Y},
title = {Urinary tract infection due to Staphylococcus schleiferi biofilm formation in the subcutaneous ureteral bypass system in a cat.},
journal = {BMC veterinary research},
volume = {21},
number = {1},
pages = {566},
pmid = {41039565},
issn = {1746-6148},
support = {24K11641//Japan Society for the Promotion of Science/ ; 22-72//ACRO Incubation Grants from Teikyo University/ ; 23-93//ACRO Incubation Grants from Teikyo University/ ; },
mesh = {Cats ; Animals ; *Biofilms/growth & development ; Female ; *Staphylococcus/physiology/isolation & purification ; *Cat Diseases/microbiology/drug therapy ; *Urinary Tract Infections/veterinary/microbiology/drug therapy ; *Staphylococcal Infections/veterinary/microbiology/drug therapy ; Ureter/surgery ; },
abstract = {BACKGROUND: Staphylococcus schleiferi is mainly isolated from dogs and occasionally infects cats. We recently encountered a case of a biofilm-related urinary tract infection (UTI) caused by S. schleiferi in a cat with a subcutaneous ureteral bypass (SUB) system. This report presents a case of biofilm formation by S. schleiferi in the SUB system and discusses the causes of UTIs.
CASE PRESENTATION: A 9-year-old female cat had been using the SUB system since 4 years-of-age. The cat had no significant clinical history or UTIs for 4 years after the first implantation of the SUB system. The SUB system was flushed once per month. When the cat was 8 years-of-age, the subcutaneous port of the SUB system was contaminated with Staphylococcus pseudintermedius and replaced with a new one. Subsequently, the SUB system had no particular problem for 8 months. The SUB system was flushed once every 2 months. However, the cat occasionally developed gross haematuria. Additionally, S. schleiferi was detected in urine. Although doxycycline was administered to the cat, 6 weeks later, the cat had cutaneous wounds with abscesses caused by excessive grooming of the skin in contact with the subcutaneous port of the SUB system. S. schleiferi was detected in a severe abscess in the cutaneous wound, and skin necrosis was observed. As bacterial contamination of the SUB system was suspected, the SUB system was removed from the cat. Scanning electron microscopy analysis revealed biofilm formation inside the locking loop catheters and outside the subcutaneous port of the SUB system. In an in vitro assay, S. schleiferi isolated from a catheter of the SUB system had low biofilm-forming ability. After the SUB system was removed, S. schleiferi was not detected in the urine and the infection was completely cured.
CONCLUSION: Considering these results, bacterial infections in cats with SUB systems should be carefully monitored, as contamination by biofilm-forming bacteria can occur regardless of flushing frequency.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Cats
Animals
*Biofilms/growth & development
Female
*Staphylococcus/physiology/isolation & purification
*Cat Diseases/microbiology/drug therapy
*Urinary Tract Infections/veterinary/microbiology/drug therapy
*Staphylococcal Infections/veterinary/microbiology/drug therapy
Ureter/surgery
RevDate: 2025-10-02
Virulence factors of Candida spp. isolated from COVID-19 patients: hydrolytic enzyme activity and biofilm formation.
BMC microbiology, 25(1):611.
During the coronavirus disease 2019 (COVID-19) pandemic, an increased prevalence of Candida co-infections has been reported. However, data on the virulence factors of Candida spp. isolated from COVID-19 patients remain scarce. This study aimed to assess the virulence factors of Candida spp. isolated from COVID-19 patients and to explore their potential associations with clinical parameters. A total of 71 Candida (C.) strains were analyzed, representing four species: 49 (69.01%) C. albicans strains, 14 (19.71%) C. glabrata strains, 7 (9.85%) C. tropicalis strains, and 1 (1.40%) C. dubliniensis strain. The activities of proteinase, phospholipase, and hemolysin, as well as biofilm-forming capacity, were evaluated. All C. albicans strains and 21 (95.45%) non-albicans Candida (NAC) strains produced proteinase. Phospholipase activity was detected in 46 (93.87%) C. albicans strains and 10 (45.45%) NAC strains. High hemolytic activity was observed in all Candida strains. Biofilm formation was detected in 31 (43.66%) Candida strains, with variable intensities. These findings highlight high levels of hydrolytic enzyme activity among Candida spp. isolated from COVID-19 patients and contribute to the growing understanding of Candida pathogenesis in immunocompromised populations, providing insights for patient management.
Additional Links: PMID-41039201
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Citation:
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@article {pmid41039201,
year = {2025},
author = {Jabrodini, A and Yazdanpanah, S and Malekzadeh, M and Shabanzadeh, S and Ahmadyan, M and Pakshir, K and Zomorodian, K},
title = {Virulence factors of Candida spp. isolated from COVID-19 patients: hydrolytic enzyme activity and biofilm formation.},
journal = {BMC microbiology},
volume = {25},
number = {1},
pages = {611},
pmid = {41039201},
issn = {1471-2180},
abstract = {During the coronavirus disease 2019 (COVID-19) pandemic, an increased prevalence of Candida co-infections has been reported. However, data on the virulence factors of Candida spp. isolated from COVID-19 patients remain scarce. This study aimed to assess the virulence factors of Candida spp. isolated from COVID-19 patients and to explore their potential associations with clinical parameters. A total of 71 Candida (C.) strains were analyzed, representing four species: 49 (69.01%) C. albicans strains, 14 (19.71%) C. glabrata strains, 7 (9.85%) C. tropicalis strains, and 1 (1.40%) C. dubliniensis strain. The activities of proteinase, phospholipase, and hemolysin, as well as biofilm-forming capacity, were evaluated. All C. albicans strains and 21 (95.45%) non-albicans Candida (NAC) strains produced proteinase. Phospholipase activity was detected in 46 (93.87%) C. albicans strains and 10 (45.45%) NAC strains. High hemolytic activity was observed in all Candida strains. Biofilm formation was detected in 31 (43.66%) Candida strains, with variable intensities. These findings highlight high levels of hydrolytic enzyme activity among Candida spp. isolated from COVID-19 patients and contribute to the growing understanding of Candida pathogenesis in immunocompromised populations, providing insights for patient management.},
}
RevDate: 2025-10-02
CmpDate: 2025-10-02
Biofilm production and virulence traits among extensively drug-resistant and methicillin-resistant Staphylococcus aureus from buffalo subclinical mastitis in Bangladesh.
Scientific reports, 15(1):34425.
Methicillin-resistant Staphylococcus aureus (MRSA) is a critical pathogen implicated in subclinical mastitis (SCM), a hidden threat to dairy productivity. This study investigated the prevalence, antibiotic resistance profiles, and virulence traits of MRSA from SCM-affected riverine buffaloes in Jamalpur, Bangladesh. A total of 344 milk samples were screened using the California Mastitis Test (CMT) and Modified Whiteside Test (MWST). Among the milk samples, 46.5% were positive for SCM by CMT. Culture, biochemical tests, and PCR confirmed 73 (21.2%) Staphylococcus spp., of which 30 (41.1%) were identified as S. aureus and 43 (58.9%) as non-aureus staphylococci (NAS). Among the 30 S. aureus-positive isolates, 10 (33.3%) were identified as methicillin-resistant S. aureus (MRSA), corresponding to a prevalence of 2.9% among the total milk samples. The MRSA isolates exhibited high multidrug resistance, especially to tetracycline (80%) and cefoxitin (80%), and commonly harbored resistance genes such as tetA (80%), aac(3)-iv (70%), and sul1 (50%). Virulence genes hla (66.7%) and sea (50%) were frequently detected, while icaA was found in 23.3% of MRSA. Notably, 60% of MRSA isolates were categorized as XDR based on international standard definitions, while 60% were biofilm producers with high MARI values up to 0.92, indicating severe resistance potential. These findings underscore a significant burden of MDR/XDR MRSA with virulence potential in buffalo SCM, posing serious risks to animal and public health.
Additional Links: PMID-41038924
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Citation:
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@article {pmid41038924,
year = {2025},
author = {Chowdhury, SR and Hosen, M and Hossain, H and Islam, R and Uddin, B and Rahman, M and Hossain, M and Rahman, M},
title = {Biofilm production and virulence traits among extensively drug-resistant and methicillin-resistant Staphylococcus aureus from buffalo subclinical mastitis in Bangladesh.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {34425},
pmid = {41038924},
issn = {2045-2322},
support = {UGC-2021-22//University Grants Commission of Bangladesh/ ; },
mesh = {Animals ; *Methicillin-Resistant Staphylococcus aureus/pathogenicity/drug effects/genetics/isolation & purification/physiology ; *Buffaloes/microbiology ; *Biofilms/growth & development/drug effects ; Bangladesh/epidemiology ; Female ; *Staphylococcal Infections/microbiology/veterinary/epidemiology ; Virulence/genetics ; *Drug Resistance, Multiple, Bacterial/genetics ; Anti-Bacterial Agents/pharmacology ; Milk/microbiology ; Microbial Sensitivity Tests ; *Mastitis/microbiology/veterinary/epidemiology ; },
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) is a critical pathogen implicated in subclinical mastitis (SCM), a hidden threat to dairy productivity. This study investigated the prevalence, antibiotic resistance profiles, and virulence traits of MRSA from SCM-affected riverine buffaloes in Jamalpur, Bangladesh. A total of 344 milk samples were screened using the California Mastitis Test (CMT) and Modified Whiteside Test (MWST). Among the milk samples, 46.5% were positive for SCM by CMT. Culture, biochemical tests, and PCR confirmed 73 (21.2%) Staphylococcus spp., of which 30 (41.1%) were identified as S. aureus and 43 (58.9%) as non-aureus staphylococci (NAS). Among the 30 S. aureus-positive isolates, 10 (33.3%) were identified as methicillin-resistant S. aureus (MRSA), corresponding to a prevalence of 2.9% among the total milk samples. The MRSA isolates exhibited high multidrug resistance, especially to tetracycline (80%) and cefoxitin (80%), and commonly harbored resistance genes such as tetA (80%), aac(3)-iv (70%), and sul1 (50%). Virulence genes hla (66.7%) and sea (50%) were frequently detected, while icaA was found in 23.3% of MRSA. Notably, 60% of MRSA isolates were categorized as XDR based on international standard definitions, while 60% were biofilm producers with high MARI values up to 0.92, indicating severe resistance potential. These findings underscore a significant burden of MDR/XDR MRSA with virulence potential in buffalo SCM, posing serious risks to animal and public health.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Animals
*Methicillin-Resistant Staphylococcus aureus/pathogenicity/drug effects/genetics/isolation & purification/physiology
*Buffaloes/microbiology
*Biofilms/growth & development/drug effects
Bangladesh/epidemiology
Female
*Staphylococcal Infections/microbiology/veterinary/epidemiology
Virulence/genetics
*Drug Resistance, Multiple, Bacterial/genetics
Anti-Bacterial Agents/pharmacology
Milk/microbiology
Microbial Sensitivity Tests
*Mastitis/microbiology/veterinary/epidemiology
RevDate: 2025-10-02
Achieving partial nitritation-anammox in membrane-aerated biofilm reactor by hydroxylamine addition.
Journal of environmental management, 394:127404 pii:S0301-4797(25)03380-8 [Epub ahead of print].
The membrane-aerated biofilm reactor (MABR) is naturally suitable for partial nitritation-anammox (PN/A) because aerobic and anaerobic microorganisms can grow in different biofilm layers. However, suppressing nitrite-oxidizing bacteria (NOB) in the oxygen-rich inner MABR biofilms remains challenging, while anammox bacteria (AnAOB) in the outer layer are more vulnerable to many harsh treatments. This study demonstrated the strategy of applying hydroxylamine (NH2OH) to achieve stable PN/A in MABR. Over 250 days, long-term experiments showed that low dissolved oxygen (0.06-0.20 mg L[-1]) could not suppress NOB, while both continuous and intermittent 10 mg L[-1] NH2OH addition not only achieved effective NOB suppression but also significantly promoted ammonia-oxidizing bacteria and AnAOB. Consequently, the nitrogen removal efficiency increased from 74.0 ± 1.1 % to 91.7 ± 1.6 %. Fundamentally, NH2OH addition rapidly changed the transcription levels of key functional genes in membrane biofilms, resulting in a significant decrease in nxrB transcription level by 68.6 ± 3.8 % and an increase in those of amoA and hzsB by 1835.8 ± 307.2 % and 314.2 ± 112.7 %, respectively. NH2OH addition resulted in the temporary accumulation of hydrazine and nitric oxide at low levels, which collectively contributed to NOB suppression. Particularly, Nitrospira, "Ca. Nitrotoga" and Nitrolancea (all three distinct NOB genera present in MABR biofilm) relative abundances decreased by 48.6 ± 7.5 %, 10.8 ± 2.5 %, and 75.0 ± 6.8 % respectively, which alleviated NOB adaptation risk. Therefore, NH2OH can be used to support NOB suppression in MABR.
Additional Links: PMID-41038100
Publisher:
PubMed:
Citation:
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@article {pmid41038100,
year = {2025},
author = {Mei, N and Jia, F and Liu, Y and Li, Y and Qi, X and Han, B and Zhang, X and Liu, T and Yao, H},
title = {Achieving partial nitritation-anammox in membrane-aerated biofilm reactor by hydroxylamine addition.},
journal = {Journal of environmental management},
volume = {394},
number = {},
pages = {127404},
doi = {10.1016/j.jenvman.2025.127404},
pmid = {41038100},
issn = {1095-8630},
abstract = {The membrane-aerated biofilm reactor (MABR) is naturally suitable for partial nitritation-anammox (PN/A) because aerobic and anaerobic microorganisms can grow in different biofilm layers. However, suppressing nitrite-oxidizing bacteria (NOB) in the oxygen-rich inner MABR biofilms remains challenging, while anammox bacteria (AnAOB) in the outer layer are more vulnerable to many harsh treatments. This study demonstrated the strategy of applying hydroxylamine (NH2OH) to achieve stable PN/A in MABR. Over 250 days, long-term experiments showed that low dissolved oxygen (0.06-0.20 mg L[-1]) could not suppress NOB, while both continuous and intermittent 10 mg L[-1] NH2OH addition not only achieved effective NOB suppression but also significantly promoted ammonia-oxidizing bacteria and AnAOB. Consequently, the nitrogen removal efficiency increased from 74.0 ± 1.1 % to 91.7 ± 1.6 %. Fundamentally, NH2OH addition rapidly changed the transcription levels of key functional genes in membrane biofilms, resulting in a significant decrease in nxrB transcription level by 68.6 ± 3.8 % and an increase in those of amoA and hzsB by 1835.8 ± 307.2 % and 314.2 ± 112.7 %, respectively. NH2OH addition resulted in the temporary accumulation of hydrazine and nitric oxide at low levels, which collectively contributed to NOB suppression. Particularly, Nitrospira, "Ca. Nitrotoga" and Nitrolancea (all three distinct NOB genera present in MABR biofilm) relative abundances decreased by 48.6 ± 7.5 %, 10.8 ± 2.5 %, and 75.0 ± 6.8 % respectively, which alleviated NOB adaptation risk. Therefore, NH2OH can be used to support NOB suppression in MABR.},
}
RevDate: 2025-10-02
Triboelectric nanogenerator-based strategy for preventing biofilm formation in orthopedic applications.
Biochemical and biophysical research communications, 786:152726 pii:S0006-291X(25)01442-1 [Epub ahead of print].
Orthopedic implant-associated infections constitute one of the most challenging complications in musculoskeletal surgery, largely attributable to the formation of tenacious bacterial biofilms. These biofilms demonstrate inherent resistance to conventional antibiotic therapies and evade host immune mechanisms. Current prophylactic approaches-such as systemic or localized antibiotic delivery and surface modifications-often fail to establish a durable protective barrier. Moreover, their efficacy is increasingly compromised by the escalating global crisis of antimicrobial resistance. Herein, we present a self-powered antibacterial system that integrates a triboelectric nanogenerator (TENG) with titanium-based orthopedic implants, capable of harvesting biomechanical energy from daily movement and delivering localized electrical stimulation. The TENG outputs peak voltages up to 140 V, sufficient to generate localized electric fields that induce bacterial migration and disrupt membrane integrity. Finite element simulations confirmed a robust electric potential difference between titanium and platinum electrodes, guiding bacterial repulsion away from the implant surface. In vitro assays demonstrated significant inhibition of Escherichia coli biofilm formation (∼34.6 % reduction), accompanied by morphological disruption of bacterial colonies. In vivo, TENG-driven stimulation accelerated wound healing, reduced bacterial coverage on implant surfaces by ∼12.6 %, and alleviated inflammatory infiltration in peri-implant tissues. Collectively, these findings establish a proof-of-concept for TENG-powered antibacterial orthopedic implants, offering a sustainable, biocompatible, and antibiotic-free strategy to combat implant-associated infections.
Additional Links: PMID-41038070
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PubMed:
Citation:
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@article {pmid41038070,
year = {2025},
author = {Yang, X and Zhang, L and Xu, L and Zhuo, F and Zhang, L and Zhang, H and Wang, X},
title = {Triboelectric nanogenerator-based strategy for preventing biofilm formation in orthopedic applications.},
journal = {Biochemical and biophysical research communications},
volume = {786},
number = {},
pages = {152726},
doi = {10.1016/j.bbrc.2025.152726},
pmid = {41038070},
issn = {1090-2104},
abstract = {Orthopedic implant-associated infections constitute one of the most challenging complications in musculoskeletal surgery, largely attributable to the formation of tenacious bacterial biofilms. These biofilms demonstrate inherent resistance to conventional antibiotic therapies and evade host immune mechanisms. Current prophylactic approaches-such as systemic or localized antibiotic delivery and surface modifications-often fail to establish a durable protective barrier. Moreover, their efficacy is increasingly compromised by the escalating global crisis of antimicrobial resistance. Herein, we present a self-powered antibacterial system that integrates a triboelectric nanogenerator (TENG) with titanium-based orthopedic implants, capable of harvesting biomechanical energy from daily movement and delivering localized electrical stimulation. The TENG outputs peak voltages up to 140 V, sufficient to generate localized electric fields that induce bacterial migration and disrupt membrane integrity. Finite element simulations confirmed a robust electric potential difference between titanium and platinum electrodes, guiding bacterial repulsion away from the implant surface. In vitro assays demonstrated significant inhibition of Escherichia coli biofilm formation (∼34.6 % reduction), accompanied by morphological disruption of bacterial colonies. In vivo, TENG-driven stimulation accelerated wound healing, reduced bacterial coverage on implant surfaces by ∼12.6 %, and alleviated inflammatory infiltration in peri-implant tissues. Collectively, these findings establish a proof-of-concept for TENG-powered antibacterial orthopedic implants, offering a sustainable, biocompatible, and antibiotic-free strategy to combat implant-associated infections.},
}
RevDate: 2025-10-02
Genetic diversity, virulence genes, antimicrobial resistance, and biofilm formation of Klebsiella pneumoniae isolated from bovine mastitis milk in South Korea.
Microbiology spectrum [Epub ahead of print].
Klebsiella pneumoniae, a zoonotic agent, is a causative pathogen of bovine mastitis. Despite its clinical relevance in dairy farms, studies on K. pneumoniae in bovine mastitis remain limited. Additionally, studies on K. pneumoniae's genetic diversity and virulence characteristics in South Korea remain limited. Therefore, in this study, we aimed to elucidate the genetic diversity, antimicrobial resistance, virulence genes, and biofilm-forming capacity of 29 K. pneumoniae strains isolated from bovine mastitis milk samples in South Korea between 2017 and 2023. Multilocus sequence typing revealed 23 sequence types, four of which were novel, indicating substantial genetic heterogeneity and the absence of a dominant clonal lineage. Excluding intrinsic resistance, the highest resistance rates were observed for tetracycline (34.5%) and sulfisoxazole (31.0%), whereas resistance to the other antibiotics tested ranged from 0% to 20.7%. In addition, multidrug resistance (MDR) was noted in 20.7% of isolates. Virulence gene analysis revealed that most isolates carried the ureA, uge, wabG, and fimH genes, whereas allS, rmpA, iucB, and iroNB were not detected. Two isolates exhibited a hypermucoviscous phenotype, and one belonged to the capsular serotype K2. All isolates demonstrated biofilm-forming ability, with moderate-to-strong production observed in over 89.0% of cases, indicating potential for persistence and treatment challenges. In conclusion, K. pneumoniae isolates from mastitis milk carried multiple virulence genes and showed MDR as well as robust biofilm formation. Therefore, continued surveillance and further characterization of K. pneumoniae are needed to support mastitis control and protect public health.IMPORTANCEKlebsiella pneumoniae is an emerging environmental pathogen associated with clinical mastitis in dairy cows, raising concerns regarding antimicrobial resistance and public health. To the best of our knowledge, this study provides the first comprehensive characterization of K. pneumoniae isolates from mastitis milk in South Korea, including analyses of genetic diversity, antimicrobial resistance, virulence factors, and biofilm formation. The findings advance our current understanding of K. pneumoniae associated with bovine mastitis and highlight the need for continued surveillance that will contribute to mastitis control efforts and safeguard public health.
Additional Links: PMID-41036847
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PubMed:
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@article {pmid41036847,
year = {2025},
author = {Kang, HJ and You, J-Y and Kim, SH and Moon, J-S and Kim, H-Y and Kim, J-M and Kang, H-M},
title = {Genetic diversity, virulence genes, antimicrobial resistance, and biofilm formation of Klebsiella pneumoniae isolated from bovine mastitis milk in South Korea.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0134325},
doi = {10.1128/spectrum.01343-25},
pmid = {41036847},
issn = {2165-0497},
abstract = {Klebsiella pneumoniae, a zoonotic agent, is a causative pathogen of bovine mastitis. Despite its clinical relevance in dairy farms, studies on K. pneumoniae in bovine mastitis remain limited. Additionally, studies on K. pneumoniae's genetic diversity and virulence characteristics in South Korea remain limited. Therefore, in this study, we aimed to elucidate the genetic diversity, antimicrobial resistance, virulence genes, and biofilm-forming capacity of 29 K. pneumoniae strains isolated from bovine mastitis milk samples in South Korea between 2017 and 2023. Multilocus sequence typing revealed 23 sequence types, four of which were novel, indicating substantial genetic heterogeneity and the absence of a dominant clonal lineage. Excluding intrinsic resistance, the highest resistance rates were observed for tetracycline (34.5%) and sulfisoxazole (31.0%), whereas resistance to the other antibiotics tested ranged from 0% to 20.7%. In addition, multidrug resistance (MDR) was noted in 20.7% of isolates. Virulence gene analysis revealed that most isolates carried the ureA, uge, wabG, and fimH genes, whereas allS, rmpA, iucB, and iroNB were not detected. Two isolates exhibited a hypermucoviscous phenotype, and one belonged to the capsular serotype K2. All isolates demonstrated biofilm-forming ability, with moderate-to-strong production observed in over 89.0% of cases, indicating potential for persistence and treatment challenges. In conclusion, K. pneumoniae isolates from mastitis milk carried multiple virulence genes and showed MDR as well as robust biofilm formation. Therefore, continued surveillance and further characterization of K. pneumoniae are needed to support mastitis control and protect public health.IMPORTANCEKlebsiella pneumoniae is an emerging environmental pathogen associated with clinical mastitis in dairy cows, raising concerns regarding antimicrobial resistance and public health. To the best of our knowledge, this study provides the first comprehensive characterization of K. pneumoniae isolates from mastitis milk in South Korea, including analyses of genetic diversity, antimicrobial resistance, virulence factors, and biofilm formation. The findings advance our current understanding of K. pneumoniae associated with bovine mastitis and highlight the need for continued surveillance that will contribute to mastitis control efforts and safeguard public health.},
}
RevDate: 2025-10-01
Transcriptomic insights into biofilm dynamics and therapeutic targets in chronic wound infections (MIMET 107281).
Journal of microbiological methods pii:S0167-7012(25)00197-6 [Epub ahead of print].
Chronic wound infections remain a significant clinical challenge, primarily due to the formation of bacterial biofilms that hinder healing and increase antimicrobial resistance. This review explores various studies focused on biofilm development, transcriptional responses, and therapeutic strategies for combating biofilm-associated infections. Using Pseudomonas aeruginosa PAO1 in ex vivo porcine skin wound models, RNA-seq analysis revealed key genes involved in biofilm formation, notably the lapA gene encoding alkaline phosphatase, which was upregulated, while denitrification pathway genes such as nirS were downregulated. Targeting these pathways through NO induction showed potential for biofilm disruption. Novel biofilm-inhibiting strategies, including silver nanoparticles, lactoferrin, and exopolysaccharides, demonstrated antibacterial, anti-biofilm, and wound-healing effects. Additionally, metal-based nanozymes (Ru-procyanidin nanoparticles) and microneedle patches embedded with cerium/zinc composites emerged as promising solutions for oxidative stress reduction and bacterial elimination in diabetic wounds. Omics approaches, particularly transcriptomics and metabolomics, have further elucidated biofilm differentiation mechanisms and host-pathogen interactions. Advanced detection methods such as electrochemical biosensors and peptide nucleic acid fluorescent in situ hybridization (PNA-FISH) have improved the identification of biofilm-associated infections. Furthermore, comparative analyses of mixed-species and single-species biofilms highlighted their differential impact on wound healing, with polybacterial biofilms causing more severe impairment. These findings underscore the importance of integrating RNA-based diagnostics, molecular therapies, and novel biomaterials to enhance chronic wound management. Future research should focus on translating these insights into clinical applications for more effective biofilm-targeted treatments.
Additional Links: PMID-41033402
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PubMed:
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@article {pmid41033402,
year = {2025},
author = {Pendor, O and Ukey, S and Trivedi, R and Umekar, M},
title = {Transcriptomic insights into biofilm dynamics and therapeutic targets in chronic wound infections (MIMET 107281).},
journal = {Journal of microbiological methods},
volume = {},
number = {},
pages = {107281},
doi = {10.1016/j.mimet.2025.107281},
pmid = {41033402},
issn = {1872-8359},
abstract = {Chronic wound infections remain a significant clinical challenge, primarily due to the formation of bacterial biofilms that hinder healing and increase antimicrobial resistance. This review explores various studies focused on biofilm development, transcriptional responses, and therapeutic strategies for combating biofilm-associated infections. Using Pseudomonas aeruginosa PAO1 in ex vivo porcine skin wound models, RNA-seq analysis revealed key genes involved in biofilm formation, notably the lapA gene encoding alkaline phosphatase, which was upregulated, while denitrification pathway genes such as nirS were downregulated. Targeting these pathways through NO induction showed potential for biofilm disruption. Novel biofilm-inhibiting strategies, including silver nanoparticles, lactoferrin, and exopolysaccharides, demonstrated antibacterial, anti-biofilm, and wound-healing effects. Additionally, metal-based nanozymes (Ru-procyanidin nanoparticles) and microneedle patches embedded with cerium/zinc composites emerged as promising solutions for oxidative stress reduction and bacterial elimination in diabetic wounds. Omics approaches, particularly transcriptomics and metabolomics, have further elucidated biofilm differentiation mechanisms and host-pathogen interactions. Advanced detection methods such as electrochemical biosensors and peptide nucleic acid fluorescent in situ hybridization (PNA-FISH) have improved the identification of biofilm-associated infections. Furthermore, comparative analyses of mixed-species and single-species biofilms highlighted their differential impact on wound healing, with polybacterial biofilms causing more severe impairment. These findings underscore the importance of integrating RNA-based diagnostics, molecular therapies, and novel biomaterials to enhance chronic wound management. Future research should focus on translating these insights into clinical applications for more effective biofilm-targeted treatments.},
}
RevDate: 2025-10-01
Biomass and metabolic activity staining biofilm techniques are not reliable enough to be used in microbiology laboratories.
Journal of microbiological methods pii:S0167-7012(25)00201-5 [Epub ahead of print].
Crystal violet and XTT staining quantify biofilms but are influenced by external factors. Testing MSSA, E. coli, and C. albicans refrigerated five weeks revealed weekly variability between researchers. These methods need careful interpretation and should be supported by more reproducible techniques for reliable results.
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@article {pmid41033401,
year = {2025},
author = {Díaz-Navarro, M and Crespo, A and Muñoz, P and Guembe, M},
title = {Biomass and metabolic activity staining biofilm techniques are not reliable enough to be used in microbiology laboratories.},
journal = {Journal of microbiological methods},
volume = {},
number = {},
pages = {107285},
doi = {10.1016/j.mimet.2025.107285},
pmid = {41033401},
issn = {1872-8359},
abstract = {Crystal violet and XTT staining quantify biofilms but are influenced by external factors. Testing MSSA, E. coli, and C. albicans refrigerated five weeks revealed weekly variability between researchers. These methods need careful interpretation and should be supported by more reproducible techniques for reliable results.},
}
RevDate: 2025-10-01
Anti-Listeria Mechanisms, Safety, and Predictive Modeling of Lacticaseibacillus casei UTMB9: Probiotic Profiling Targeting Virulence Gene Expression and Biofilm Formation.
Microbial pathogenesis pii:S0882-4010(25)00796-X [Epub ahead of print].
There is growing interest in probiotics due to their potential to confer health benefits. This study aimed to explore the potential probiotic characteristics, gene expression linked to biofilm formation, and anti-biofilm properties of Lacticaseibacillus casei UTMB9. L. casei UTMB9 tolerates acidic environments, with survival rates of 6.90, 7.59, and 7.96 log CFU/mL at pH 2.5, 3.5, and 4.5, respectively, and exhibits slight growth inhibition under bile concentrations up to 0.7 %. Viability declined modestly from 8.51 to 6.61 log colony forming unit (CFU)/mL under simulated gastrointestinal conditions. Surface hydrophobicity (40.9 %), auto-aggregation (30.9 %), co-aggregation (40.8 %), and adhesion (11.9 %) support its adherence potential. Antimicrobial assays showed most potent inhibition against Listeria monocytogenes (9.70 mm) versus E. coli (4.74 mm). Scanning Electron Microscopy (SEM) imaging revealed pronounced damage to L. monocytogenes cells after exposure to cell-free supernatant (CFS), accompanied by significant downregulation of prfA and flaA, and marked antibiofilm suppression. It also demonstrated antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) 43.6 %, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) 47.5 %, linoleic acid oxidation inhibition 30.3 %) and moderate anticancer activity (IC50 ≈ 55-62 mg/mL). The strain reduced cholesterol uptake by 41.9 %, was broadly antibiotic-sensitive (except for partial resistance to ampicillin), and lacked biogenic amine production, DNase, or hemolytic activity. In the second part of this study, Gaussian Process Regression (GPR) was used to predict acidity and bile salt. GPR accurately predicted acidity and bile tolerance (MAPE = 0.22 % and 0.18 %; R[2]≥ 0.99). These findings position L. casei as a promising probiotic agent with robust antimicrobial, antibiofilm, antioxidant, and predictive model-supported features.
Additional Links: PMID-41033369
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PubMed:
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@article {pmid41033369,
year = {2025},
author = {Namazi, P and Behbahani, BA and Noshad, M and Vasiee, A and Taki, M and Joyandeh, H},
title = {Anti-Listeria Mechanisms, Safety, and Predictive Modeling of Lacticaseibacillus casei UTMB9: Probiotic Profiling Targeting Virulence Gene Expression and Biofilm Formation.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {108071},
doi = {10.1016/j.micpath.2025.108071},
pmid = {41033369},
issn = {1096-1208},
abstract = {There is growing interest in probiotics due to their potential to confer health benefits. This study aimed to explore the potential probiotic characteristics, gene expression linked to biofilm formation, and anti-biofilm properties of Lacticaseibacillus casei UTMB9. L. casei UTMB9 tolerates acidic environments, with survival rates of 6.90, 7.59, and 7.96 log CFU/mL at pH 2.5, 3.5, and 4.5, respectively, and exhibits slight growth inhibition under bile concentrations up to 0.7 %. Viability declined modestly from 8.51 to 6.61 log colony forming unit (CFU)/mL under simulated gastrointestinal conditions. Surface hydrophobicity (40.9 %), auto-aggregation (30.9 %), co-aggregation (40.8 %), and adhesion (11.9 %) support its adherence potential. Antimicrobial assays showed most potent inhibition against Listeria monocytogenes (9.70 mm) versus E. coli (4.74 mm). Scanning Electron Microscopy (SEM) imaging revealed pronounced damage to L. monocytogenes cells after exposure to cell-free supernatant (CFS), accompanied by significant downregulation of prfA and flaA, and marked antibiofilm suppression. It also demonstrated antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) 43.6 %, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) 47.5 %, linoleic acid oxidation inhibition 30.3 %) and moderate anticancer activity (IC50 ≈ 55-62 mg/mL). The strain reduced cholesterol uptake by 41.9 %, was broadly antibiotic-sensitive (except for partial resistance to ampicillin), and lacked biogenic amine production, DNase, or hemolytic activity. In the second part of this study, Gaussian Process Regression (GPR) was used to predict acidity and bile salt. GPR accurately predicted acidity and bile tolerance (MAPE = 0.22 % and 0.18 %; R[2]≥ 0.99). These findings position L. casei as a promising probiotic agent with robust antimicrobial, antibiofilm, antioxidant, and predictive model-supported features.},
}
RevDate: 2025-10-01
Investigating the release of active compounds and cytotoxicity of thymol/gallic acid/β-cyclodextrin bio-nanocomposite: a targeted strategy with the approach of disrupting the genes involved in the quorum sensing system and biofilm formation in P. aeruginosa (PAO1).
Preparative biochemistry & biotechnology [Epub ahead of print].
The quorum sensing (QS) system and cell-to-cell communication have had a significant impact on biofilm formation and virulence factor increase in Pseudomonas aeruginosa (P. aeruginosa), making this opportunistic pathogen a global concern and potentially life-threatening agent. The present study aimed to create an innovative pharmaceutical bio-nanocomposite (BNC) comprising thymol (THY) and gallic acid (GA) based on β-cyclodextrin (β-CD), which was used to investigate the release kinetics of active compounds, the level of cytotoxicity, antibacterial and anti-biofilm potential, and measuring the expression of genes effective in QS in the strain PAO1 pays P. aeruginosa. Based on this, physicochemical characteristics of the synthesized BNC were determined using Fourier transform infrared spectroscopy analysis (FTIR), UV-vis measurement, dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The BNC's antibacterial and anti-biofilm capabilities were assessed using the PAO1 reference strain of P. aeruginosa and the expression level of QS-effective genes (rhlI, rhlR, lasI, and lasR) in bacteria was also evaluated in the presence of the synthesized BNC. The results of FTIR spectroscopy show the formation of intramolecular hydrogen bonds between THY, GA and β-CD. Absorption peaks of the UV-vis spectroscopy spectrum of the synthesized BNC at wavelengths of 217 and 272 nm are confirmed successful encapsulation of the THY and GA into the β-CD. The maximum size of the synthesized BNC was recorded as 356.3 nm with a polydispersity index (PDI) of 0.816. SEM and TEM micrographs show the presence of THY/GA active compounds in the pores in β-CD and the formation of a dense polymer network. After 360 minutes of release kinetics, more than 70% of the complex's active chemicals had been released. The biological complex's low toxicity is indicated by average cell survival of more than 65% and the ability to preserve the spindle shape of normal fibroblast cells at high concentrations. The PAO1 strain has minimum inhibitory concentrations (MIC) of 323 and 199.6 μg/mL for minimal biofilm inhibition concentration 50% (MBIC50). The decrease in rhlI and rhlR gene expression relative to the control group (without treatment) suggests that the active chemicals released from the biological complex interact and disrupt the QS pathway. Overall, the synthesized pharmaceutical complex has promise as a clever and effective option for future research and practical advances, as well as the development of complementary therapies.
Additional Links: PMID-41032695
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PubMed:
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@article {pmid41032695,
year = {2025},
author = {Ashrafi, B and Heydari, R and Rezaei, F and Beiranvand, B and Pajouhi, N and Rashidipour, M and Taherikalani, M and Soroush, S},
title = {Investigating the release of active compounds and cytotoxicity of thymol/gallic acid/β-cyclodextrin bio-nanocomposite: a targeted strategy with the approach of disrupting the genes involved in the quorum sensing system and biofilm formation in P. aeruginosa (PAO1).},
journal = {Preparative biochemistry & biotechnology},
volume = {},
number = {},
pages = {1-17},
doi = {10.1080/10826068.2025.2563676},
pmid = {41032695},
issn = {1532-2297},
abstract = {The quorum sensing (QS) system and cell-to-cell communication have had a significant impact on biofilm formation and virulence factor increase in Pseudomonas aeruginosa (P. aeruginosa), making this opportunistic pathogen a global concern and potentially life-threatening agent. The present study aimed to create an innovative pharmaceutical bio-nanocomposite (BNC) comprising thymol (THY) and gallic acid (GA) based on β-cyclodextrin (β-CD), which was used to investigate the release kinetics of active compounds, the level of cytotoxicity, antibacterial and anti-biofilm potential, and measuring the expression of genes effective in QS in the strain PAO1 pays P. aeruginosa. Based on this, physicochemical characteristics of the synthesized BNC were determined using Fourier transform infrared spectroscopy analysis (FTIR), UV-vis measurement, dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The BNC's antibacterial and anti-biofilm capabilities were assessed using the PAO1 reference strain of P. aeruginosa and the expression level of QS-effective genes (rhlI, rhlR, lasI, and lasR) in bacteria was also evaluated in the presence of the synthesized BNC. The results of FTIR spectroscopy show the formation of intramolecular hydrogen bonds between THY, GA and β-CD. Absorption peaks of the UV-vis spectroscopy spectrum of the synthesized BNC at wavelengths of 217 and 272 nm are confirmed successful encapsulation of the THY and GA into the β-CD. The maximum size of the synthesized BNC was recorded as 356.3 nm with a polydispersity index (PDI) of 0.816. SEM and TEM micrographs show the presence of THY/GA active compounds in the pores in β-CD and the formation of a dense polymer network. After 360 minutes of release kinetics, more than 70% of the complex's active chemicals had been released. The biological complex's low toxicity is indicated by average cell survival of more than 65% and the ability to preserve the spindle shape of normal fibroblast cells at high concentrations. The PAO1 strain has minimum inhibitory concentrations (MIC) of 323 and 199.6 μg/mL for minimal biofilm inhibition concentration 50% (MBIC50). The decrease in rhlI and rhlR gene expression relative to the control group (without treatment) suggests that the active chemicals released from the biological complex interact and disrupt the QS pathway. Overall, the synthesized pharmaceutical complex has promise as a clever and effective option for future research and practical advances, as well as the development of complementary therapies.},
}
RevDate: 2025-10-01
CmpDate: 2025-10-01
Oral Biofilm and Gender-Specific Health Considerations.
Cureus, 17(8):e91289.
Oral biofilm plays a central role in the development of periodontal and systemic diseases, with growing evidence highlighting significant gender-specific differences. Hormonal fluctuations in women, during puberty, menstruation, pregnancy, menopause, and with oral contraceptive use, may alter the composition and behavior of oral biofilm, increasing susceptibility to gingival inflammation and periodontal disease. Conditions such as polycystic ovary syndrome (PCOS), osteoporosis, and pregnancy-associated gingivitis further demonstrate the influence of endocrine factors on oral health. In men, higher rates of severe periodontitis are observed, potentially linked to testosterone-related immune responses and behavioral factors with associations to lower sperm counts, increased incidence of prostate cancer, and erectile dysfunction. These distinctions underscore the importance of considering sex-specific biology in both the prevention and management of oral and systemic diseases influenced by biofilm. This study reviews the connections between gender-specific health and oral biofilm.
Additional Links: PMID-41030757
PubMed:
Citation:
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@article {pmid41030757,
year = {2025},
author = {Kurtzman, GM and Horowitz, RA and Johnston, R and Lanphier, L},
title = {Oral Biofilm and Gender-Specific Health Considerations.},
journal = {Cureus},
volume = {17},
number = {8},
pages = {e91289},
pmid = {41030757},
issn = {2168-8184},
abstract = {Oral biofilm plays a central role in the development of periodontal and systemic diseases, with growing evidence highlighting significant gender-specific differences. Hormonal fluctuations in women, during puberty, menstruation, pregnancy, menopause, and with oral contraceptive use, may alter the composition and behavior of oral biofilm, increasing susceptibility to gingival inflammation and periodontal disease. Conditions such as polycystic ovary syndrome (PCOS), osteoporosis, and pregnancy-associated gingivitis further demonstrate the influence of endocrine factors on oral health. In men, higher rates of severe periodontitis are observed, potentially linked to testosterone-related immune responses and behavioral factors with associations to lower sperm counts, increased incidence of prostate cancer, and erectile dysfunction. These distinctions underscore the importance of considering sex-specific biology in both the prevention and management of oral and systemic diseases influenced by biofilm. This study reviews the connections between gender-specific health and oral biofilm.},
}
RevDate: 2025-10-01
CmpDate: 2025-10-01
An investigation on anti-biofilm potential of Aegle marmelos fruit extract against multi-drug-resistant Staphylococcus aureus.
BMC complementary medicine and therapies, 25(1):334.
BACKGROUND: Staphylococcus aureus, member of ESKAPEE pathogens is a noteworthy contributor to the global crisis rising due to antimicrobial resistance. Biofilms are the primary reason behind the increased antibiotic resistance and tolerance of pathogens. Hence targeting bacterial biofilms has been prioritized as an alternative strategy to counter antibiotic resistance. Aegle marmelos has gained prominence in Indian traditional medicine as seeds, fruits, leaves, bark and roots of this plant are being in use extensively in treating several kinds of ailments by the inhabitants of this subcontinent due to its ethno-pharmacological relevance. The fruit of this plant has been found with remarkable anti-bacterial properties along with other therapeutic efficacies. The present study aimed to identify the anti-biofilm potential of methanolic fruit extract of Aegle marmelos (AMFE) against multi-drug-resistant (MDR) S. aureus strains as a resort to counter the global crisis of antimicrobial resistance for alternative approaches.
RESULTS: MBIC and MBEC of AMFE ranged between 100 and 200 µg.mL[-1] and 300-500 µg.mL[-1], respectively. AMFE could substantially reduce the carbohydrate and protein content of the exo-polymeric substance (EPS), crucial for biofilm production. Expressions of major biofilm promoting genes icaAD and its accessory sarA were down-regulated upon AMFE treatment as revealed from qRT-PCR analysis whereas the quorum sensing gene agr that promotes biofilm detachment was up-regulated. Fluorescence, scanning electron and atomic force microscopic studies confirm the reduction of biofilm biomass upon AMFE treatment. Up to 10 mg.mL[-1] AMFE was non-toxic to human lymphocytes with cell viability of 75.35%. GC-MS and FT-IR studies could detect the bioactive components where 9-octadecenoic acid, n-hexadecanoic acid, 9,12-octadecadienoic acid, methyl 4,7,10- hexadecatrienoate were the major components.
CONCLUSION: Anti-biofilm activity of AMFE towards MDR S. aureus have been established through in vitro biochemical and gene expression studies that were further substantiated by microscopic studies which reveal that AMFE could be explored in the management of S. aureus-associated infections.
Additional Links: PMID-41029314
PubMed:
Citation:
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@article {pmid41029314,
year = {2025},
author = {Jana, D and Manna, T and Guchhait, KC and Panja, S and Karmakar, A and Ballav, S and Hazra, S and Dey, S and Panda, AK and Ghosh, C},
title = {An investigation on anti-biofilm potential of Aegle marmelos fruit extract against multi-drug-resistant Staphylococcus aureus.},
journal = {BMC complementary medicine and therapies},
volume = {25},
number = {1},
pages = {334},
pmid = {41029314},
issn = {2662-7671},
mesh = {*Biofilms/drug effects ; *Plant Extracts/pharmacology ; *Aegle/chemistry ; *Anti-Bacterial Agents/pharmacology ; Fruit/chemistry ; *Staphylococcus aureus/drug effects ; *Drug Resistance, Multiple, Bacterial/drug effects ; Microbial Sensitivity Tests ; Humans ; },
abstract = {BACKGROUND: Staphylococcus aureus, member of ESKAPEE pathogens is a noteworthy contributor to the global crisis rising due to antimicrobial resistance. Biofilms are the primary reason behind the increased antibiotic resistance and tolerance of pathogens. Hence targeting bacterial biofilms has been prioritized as an alternative strategy to counter antibiotic resistance. Aegle marmelos has gained prominence in Indian traditional medicine as seeds, fruits, leaves, bark and roots of this plant are being in use extensively in treating several kinds of ailments by the inhabitants of this subcontinent due to its ethno-pharmacological relevance. The fruit of this plant has been found with remarkable anti-bacterial properties along with other therapeutic efficacies. The present study aimed to identify the anti-biofilm potential of methanolic fruit extract of Aegle marmelos (AMFE) against multi-drug-resistant (MDR) S. aureus strains as a resort to counter the global crisis of antimicrobial resistance for alternative approaches.
RESULTS: MBIC and MBEC of AMFE ranged between 100 and 200 µg.mL[-1] and 300-500 µg.mL[-1], respectively. AMFE could substantially reduce the carbohydrate and protein content of the exo-polymeric substance (EPS), crucial for biofilm production. Expressions of major biofilm promoting genes icaAD and its accessory sarA were down-regulated upon AMFE treatment as revealed from qRT-PCR analysis whereas the quorum sensing gene agr that promotes biofilm detachment was up-regulated. Fluorescence, scanning electron and atomic force microscopic studies confirm the reduction of biofilm biomass upon AMFE treatment. Up to 10 mg.mL[-1] AMFE was non-toxic to human lymphocytes with cell viability of 75.35%. GC-MS and FT-IR studies could detect the bioactive components where 9-octadecenoic acid, n-hexadecanoic acid, 9,12-octadecadienoic acid, methyl 4,7,10- hexadecatrienoate were the major components.
CONCLUSION: Anti-biofilm activity of AMFE towards MDR S. aureus have been established through in vitro biochemical and gene expression studies that were further substantiated by microscopic studies which reveal that AMFE could be explored in the management of S. aureus-associated infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
*Plant Extracts/pharmacology
*Aegle/chemistry
*Anti-Bacterial Agents/pharmacology
Fruit/chemistry
*Staphylococcus aureus/drug effects
*Drug Resistance, Multiple, Bacterial/drug effects
Microbial Sensitivity Tests
Humans
RevDate: 2025-10-01
Pubescine as a Novel Antibacterial Agent Against Vancomycin-Resistant Enterococcus: Growth Inhibition, Antibiotic Synergy, and Anti-Biofilm Activity.
Current pharmaceutical biotechnology pii:CPB-EPUB-150818 [Epub ahead of print].
INTRODUCTION: The rise of Vancomycin-Resistant Enterococcus (VRE) has become a major public health concern due to its resistance to conventional antibiotics and ability to form biofilms. The urgent need for novel therapeutic strategies has led to increased interest in natural compounds with antimicrobial potential. Pubescine (PBN), a steroidal alkaloid isolated from Holarrhena pubescens, has demonstrated antimicrobial properties, but its efficacy against VRE remains unexplored.
METHODS: PBN was isolated and purified from Holarrhena pubescens using chromatographic techniques and identified through spectroscopic analysis. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined via broth microdilution assays. Time-kill assays assessed the bacteriostatic or bactericidal nature of PBN. Resistance development was evaluated through prolonged bacterial exposure to subinhibitory concentrations. Synergistic interactions with vancomycin and cefoxitin were analyzed using checkerboard microdilution assays. Biofilm formation and eradication were assessed via crystal violet staining and fluorescence imaging. Metabolic activity and oxidative stress induction were measured using the Alamar Blue assay and Reactive Oxygen Species (ROS) quantification, respectively.
RESULTS: PBN exhibited concentration-dependent inhibition of VRE growth, primarily exerting a bacteriostatic effect without promoting the development of resistance. Checkerboard assays revealed strong synergy between PBN and vancomycin (FICI = 0.1875) and cefoxitin (FICI = 0.3125), suggesting that PBN enhances the efficacy of these antibiotics.
DISCUSSION: PBN significantly reduced biofilm formation and facilitated biofilm disruption at concentrations as low as 4 μg/mL. Metabolic assays demonstrated that PBN suppresses bacterial metabolic activity, while ROS quantification indicated a substantial increase in oxidative stress, suggesting a multi-targeted mechanism of action.
CONCLUSION: These findings establish PBN as a promising antimicrobial agent with potent activity against vancomycin-resistant Enterococcus faecalis. Its ability to enhance antibiotic efficacy, inhibit biofilm formation, and induce oxidative stress underscores its potential as a novel therapeutic strategy against multidrug-resistant infections. Further in vivo studies and pharmacokinetic evaluations are warranted to assess its clinical applicability.
Additional Links: PMID-41029014
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PubMed:
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@article {pmid41029014,
year = {2025},
author = {Soltane, R},
title = {Pubescine as a Novel Antibacterial Agent Against Vancomycin-Resistant Enterococcus: Growth Inhibition, Antibiotic Synergy, and Anti-Biofilm Activity.},
journal = {Current pharmaceutical biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.2174/0113892010399006250923063945},
pmid = {41029014},
issn = {1873-4316},
abstract = {INTRODUCTION: The rise of Vancomycin-Resistant Enterococcus (VRE) has become a major public health concern due to its resistance to conventional antibiotics and ability to form biofilms. The urgent need for novel therapeutic strategies has led to increased interest in natural compounds with antimicrobial potential. Pubescine (PBN), a steroidal alkaloid isolated from Holarrhena pubescens, has demonstrated antimicrobial properties, but its efficacy against VRE remains unexplored.
METHODS: PBN was isolated and purified from Holarrhena pubescens using chromatographic techniques and identified through spectroscopic analysis. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined via broth microdilution assays. Time-kill assays assessed the bacteriostatic or bactericidal nature of PBN. Resistance development was evaluated through prolonged bacterial exposure to subinhibitory concentrations. Synergistic interactions with vancomycin and cefoxitin were analyzed using checkerboard microdilution assays. Biofilm formation and eradication were assessed via crystal violet staining and fluorescence imaging. Metabolic activity and oxidative stress induction were measured using the Alamar Blue assay and Reactive Oxygen Species (ROS) quantification, respectively.
RESULTS: PBN exhibited concentration-dependent inhibition of VRE growth, primarily exerting a bacteriostatic effect without promoting the development of resistance. Checkerboard assays revealed strong synergy between PBN and vancomycin (FICI = 0.1875) and cefoxitin (FICI = 0.3125), suggesting that PBN enhances the efficacy of these antibiotics.
DISCUSSION: PBN significantly reduced biofilm formation and facilitated biofilm disruption at concentrations as low as 4 μg/mL. Metabolic assays demonstrated that PBN suppresses bacterial metabolic activity, while ROS quantification indicated a substantial increase in oxidative stress, suggesting a multi-targeted mechanism of action.
CONCLUSION: These findings establish PBN as a promising antimicrobial agent with potent activity against vancomycin-resistant Enterococcus faecalis. Its ability to enhance antibiotic efficacy, inhibit biofilm formation, and induce oxidative stress underscores its potential as a novel therapeutic strategy against multidrug-resistant infections. Further in vivo studies and pharmacokinetic evaluations are warranted to assess its clinical applicability.},
}
RevDate: 2025-10-01
CmpDate: 2025-10-01
Development of 3D-printed Ti-MXene incorporated chitosan/HAP nano-composite soft-bone scaffold and its mechanical, anti-biofilm and cell-viability studies.
Scientific reports, 15(1):33762.
The prevailing scientific literature suggests that implantable plates demand resurgery, and it will result in corrosion behaviour and the formation of biofilm on the scaffold by Staphylococcus aureus, which is capable of causing a bone surgery-related detrimental effect in two-thirds of the people suffering from osteomyelitis diseases. The development of a nanocomposite scaffold by 3D-bioprinting to improve potent mechanical features with substantial biological characteristics. By incorporating hydroxyapatite (10% w/v) into chitosan (10% w/v) at 1:1 ratio mimicking the natural structure of soft bone tissue. Furthermore, a better structural hydrogel was synthesized for 3D bio-printing through the incorporation of Ti-MXene into the Chitosan/Hydroxyapatite nanocomposite at two distinct ratios. Apart from this, 0.3 mg/mL of Ti-MXene containing 3D-printed nanocomposite scaffold revealed better structural morphology with very less biofilm formation when compared to other 3D-printed scaffolds. Furthermore, mechanical testing such as tensile revealed 23.3 MPa for 0.3 mg/mL of Ti-MXene incorporated Chitosan/HAP nanocomposite. Additionally, this scaffold exhibits a favorable contact angle (74.70°) with a low swelling ratio (27.6%) and degradation rate (1.1%). Further, an in-vitro cell viability test showed a higher cell attachment without cell death. These results find the absence of toxic effect and suggest an enhancement in cell attachment.
Additional Links: PMID-41028885
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@article {pmid41028885,
year = {2025},
author = {Veerabathiran, A and Subramania, AK and Saikia, M and Manikandamaharaj, TS and Rajendra, SP and Duraisamy, R and Angaiah, S},
title = {Development of 3D-printed Ti-MXene incorporated chitosan/HAP nano-composite soft-bone scaffold and its mechanical, anti-biofilm and cell-viability studies.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {33762},
pmid = {41028885},
issn = {2045-2322},
support = {RSPD2025R723//Researchers Supporting Project/ ; },
mesh = {*Chitosan/chemistry ; *Printing, Three-Dimensional ; *Biofilms/drug effects/growth & development ; *Titanium/chemistry ; *Nanocomposites/chemistry ; *Tissue Scaffolds/chemistry ; Cell Survival/drug effects ; *Durapatite/chemistry ; Humans ; Staphylococcus aureus/drug effects/physiology ; Tissue Engineering ; Biocompatible Materials/chemistry ; Bone and Bones ; Materials Testing ; Nitrites ; Transition Elements ; },
abstract = {The prevailing scientific literature suggests that implantable plates demand resurgery, and it will result in corrosion behaviour and the formation of biofilm on the scaffold by Staphylococcus aureus, which is capable of causing a bone surgery-related detrimental effect in two-thirds of the people suffering from osteomyelitis diseases. The development of a nanocomposite scaffold by 3D-bioprinting to improve potent mechanical features with substantial biological characteristics. By incorporating hydroxyapatite (10% w/v) into chitosan (10% w/v) at 1:1 ratio mimicking the natural structure of soft bone tissue. Furthermore, a better structural hydrogel was synthesized for 3D bio-printing through the incorporation of Ti-MXene into the Chitosan/Hydroxyapatite nanocomposite at two distinct ratios. Apart from this, 0.3 mg/mL of Ti-MXene containing 3D-printed nanocomposite scaffold revealed better structural morphology with very less biofilm formation when compared to other 3D-printed scaffolds. Furthermore, mechanical testing such as tensile revealed 23.3 MPa for 0.3 mg/mL of Ti-MXene incorporated Chitosan/HAP nanocomposite. Additionally, this scaffold exhibits a favorable contact angle (74.70°) with a low swelling ratio (27.6%) and degradation rate (1.1%). Further, an in-vitro cell viability test showed a higher cell attachment without cell death. These results find the absence of toxic effect and suggest an enhancement in cell attachment.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Chitosan/chemistry
*Printing, Three-Dimensional
*Biofilms/drug effects/growth & development
*Titanium/chemistry
*Nanocomposites/chemistry
*Tissue Scaffolds/chemistry
Cell Survival/drug effects
*Durapatite/chemistry
Humans
Staphylococcus aureus/drug effects/physiology
Tissue Engineering
Biocompatible Materials/chemistry
Bone and Bones
Materials Testing
Nitrites
Transition Elements
RevDate: 2025-10-01
CmpDate: 2025-10-01
Murraya koenigii methanolic extract inhibits bacterial growth and biofilm of Staphylococcus aureus and Enterococcus faecalis.
Scientific reports, 15(1):34056.
Hospital-acquired infections caused by Staphylococcus aureus and Enterococcus faecalis are significant global health challenges due to their biofilm-forming ability, also contributing to the derived antibiotic resistance and environmental persistence. This growing resistance poses serious global health challenges, emphasizing the need for better surveillance and new treatments. Plant-derived bioactives have emerged as possible therapeutics to such opportunistic pathogens and they are potential alternatives to traditional antimicrobials. This study investigates the in vitro activity of Murraya koenigii's methanolic (MKM) leaf extract and its compounds against the growth and biofilm-forming ability of S. aureus and E. faecalis. Results revealed that the MKM extract effectively inhibited the growth of S. aureus and E. faecalis at their respective MIC levels. Furthermore, flow cytometry and confocal imaging demonstrated substantial membrane damage in MKM-treated cells compared to DMSO-treated and untreated controls. Additionally, the MKM extract significantly disrupts biofilm formation and leads to reduced extracellular polymeric substance (EPS) production. Scanning electron microscopy provided visual evidence of disrupted biofilm architecture following MKM extract treatment. HR-LC/MS analysis identified bioactive compounds within the extract, which were further evaluated for drug-likeness properties through ADME analysis. In silico molecular docking studies confirmed strong binding affinities of MKM-derived compounds with key biofilm-related receptor proteins, SpA in S. aureus and Esp in E. faecalis. These findings highlight the significant potential of MKM extract as a novel and effective phytotherapeutic resource for developing strategies to combat biofilm-associated infections.
Additional Links: PMID-41028857
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Citation:
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@article {pmid41028857,
year = {2025},
author = {Kashyap, S and Rathod, Y and Biswas, S},
title = {Murraya koenigii methanolic extract inhibits bacterial growth and biofilm of Staphylococcus aureus and Enterococcus faecalis.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {34056},
pmid = {41028857},
issn = {2045-2322},
support = {BT/INF/22/SP42543/2021//Department of Biotechnology, Ministry of Science and Technology, India/ ; BT/INF/22/SP42543/2021//Department of Biotechnology, Ministry of Science and Technology, India/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Enterococcus faecalis/drug effects/growth & development/physiology ; *Plant Extracts/pharmacology/chemistry ; *Staphylococcus aureus/drug effects/growth & development/physiology ; *Murraya/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry ; Microbial Sensitivity Tests ; Molecular Docking Simulation ; Methanol/chemistry ; Plant Leaves/chemistry ; Humans ; Bacterial Lysates ; },
abstract = {Hospital-acquired infections caused by Staphylococcus aureus and Enterococcus faecalis are significant global health challenges due to their biofilm-forming ability, also contributing to the derived antibiotic resistance and environmental persistence. This growing resistance poses serious global health challenges, emphasizing the need for better surveillance and new treatments. Plant-derived bioactives have emerged as possible therapeutics to such opportunistic pathogens and they are potential alternatives to traditional antimicrobials. This study investigates the in vitro activity of Murraya koenigii's methanolic (MKM) leaf extract and its compounds against the growth and biofilm-forming ability of S. aureus and E. faecalis. Results revealed that the MKM extract effectively inhibited the growth of S. aureus and E. faecalis at their respective MIC levels. Furthermore, flow cytometry and confocal imaging demonstrated substantial membrane damage in MKM-treated cells compared to DMSO-treated and untreated controls. Additionally, the MKM extract significantly disrupts biofilm formation and leads to reduced extracellular polymeric substance (EPS) production. Scanning electron microscopy provided visual evidence of disrupted biofilm architecture following MKM extract treatment. HR-LC/MS analysis identified bioactive compounds within the extract, which were further evaluated for drug-likeness properties through ADME analysis. In silico molecular docking studies confirmed strong binding affinities of MKM-derived compounds with key biofilm-related receptor proteins, SpA in S. aureus and Esp in E. faecalis. These findings highlight the significant potential of MKM extract as a novel and effective phytotherapeutic resource for developing strategies to combat biofilm-associated infections.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Enterococcus faecalis/drug effects/growth & development/physiology
*Plant Extracts/pharmacology/chemistry
*Staphylococcus aureus/drug effects/growth & development/physiology
*Murraya/chemistry
*Anti-Bacterial Agents/pharmacology/chemistry
Microbial Sensitivity Tests
Molecular Docking Simulation
Methanol/chemistry
Plant Leaves/chemistry
Humans
Bacterial Lysates
RevDate: 2025-09-30
CmpDate: 2025-10-01
Utilization of clove and cinnamon essential oils as an alternative to inhibit MDR and biofilm producing E. coli from raw chicken meat.
Scientific reports, 15(1):34079.
The microbial contamination and spoilage found in chicken meat is responsible for food-borne illnesses and outbreaks leading to hospitalizations. E. coli is the most commonly reported microorganism. The dissemination of bacterial strain with biofilm-formation ability and resistance to antimicrobials at the end of the food chain is a global concern; as well. Eco-friendly and novel means like essential oils are required to break these vicious patterns and ensure the longevity of quality food products. The study aimed to probe the prevalence, pattern of antimicrobial resistance and the biofilm formation ability in E. coli isolated from chicken meat samples. It also explored the antimicrobial and anti-biofilm formation ability of clove and cinnamon essential oils. 150 chicken meat samples from different localities of Karachi, Pakistan were isolated and identified by selective culturing and conventional microbiological techniques. Following antibiogram analysis, antibacterial activity of clove and cinnamon essential oils was evaluated. Putative biofilm production ability was also explored using the test tube, microplate reader, and scanning electron microscopy. Finally, the molecular characterization of potentially strong biofilm producers was done along with exploration of the pathogenic gene (PapC). 49 chicken meat samples out of 150 were contaminated with E. coli. 90% (44 isolates) of E. coli were multidrug resistant. 59.2% (29 isolates) were biofilm producers (BPs). Out of 29 BPs, nine (31%) were strong biofilm producers (SBPs). No significant correlations were observed between antimicrobial resistance and biofilm producing ability of E. coli isolates (p value ≥ 0.05). 40% of SBPs were inhibited when subjected to both clove (MIC: 250 to 500 µL/mL) and cinnamon (MIC: 62.5 µL/mL) EOs. Activity of both neat CO and CinO had no significant difference (p value ≥ 0.05). The identity of 3 SBPs (Strains: AR11E, AR12E and AR22E) were further confirmed by molecular identification (16SrRNA) and SEM revealed potential degradation of the bacterial cells with a reduction in count when treated with CinO and CO. Only one strain (AR22E) was positive for the papC gene. The prevalence of E. coli and strong-biofilm producers in retail chicken meat was not very high; however, the majority of the isolates were multi-drug resistant. Therefore, it is important to keep a tab on the prevalence of these commensal and pathogenic microorganisms in retail chicken meat since they are an exposure site close to the consumer. The use of alternative means like essential oils in poultry, meat and meat-products is a good strategy since they have proven efficacy against pathogenic E. coli.
Additional Links: PMID-41028113
PubMed:
Citation:
show bibtex listing
hide bibtex listing
@article {pmid41028113,
year = {2025},
author = {Rafique, A and Baig, N and Naim, A and Rafiq, I},
title = {Utilization of clove and cinnamon essential oils as an alternative to inhibit MDR and biofilm producing E. coli from raw chicken meat.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {34079},
pmid = {41028113},
issn = {2045-2322},
mesh = {*Biofilms/drug effects/growth & development ; Animals ; *Escherichia coli/drug effects/isolation & purification/physiology/genetics ; Chickens/microbiology ; *Oils, Volatile/pharmacology ; *Meat/microbiology ; *Cinnamomum zeylanicum/chemistry ; *Anti-Bacterial Agents/pharmacology ; *Drug Resistance, Multiple, Bacterial/drug effects ; *Clove Oil/pharmacology ; Microbial Sensitivity Tests ; Syzygium/chemistry ; Food Microbiology ; },
abstract = {The microbial contamination and spoilage found in chicken meat is responsible for food-borne illnesses and outbreaks leading to hospitalizations. E. coli is the most commonly reported microorganism. The dissemination of bacterial strain with biofilm-formation ability and resistance to antimicrobials at the end of the food chain is a global concern; as well. Eco-friendly and novel means like essential oils are required to break these vicious patterns and ensure the longevity of quality food products. The study aimed to probe the prevalence, pattern of antimicrobial resistance and the biofilm formation ability in E. coli isolated from chicken meat samples. It also explored the antimicrobial and anti-biofilm formation ability of clove and cinnamon essential oils. 150 chicken meat samples from different localities of Karachi, Pakistan were isolated and identified by selective culturing and conventional microbiological techniques. Following antibiogram analysis, antibacterial activity of clove and cinnamon essential oils was evaluated. Putative biofilm production ability was also explored using the test tube, microplate reader, and scanning electron microscopy. Finally, the molecular characterization of potentially strong biofilm producers was done along with exploration of the pathogenic gene (PapC). 49 chicken meat samples out of 150 were contaminated with E. coli. 90% (44 isolates) of E. coli were multidrug resistant. 59.2% (29 isolates) were biofilm producers (BPs). Out of 29 BPs, nine (31%) were strong biofilm producers (SBPs). No significant correlations were observed between antimicrobial resistance and biofilm producing ability of E. coli isolates (p value ≥ 0.05). 40% of SBPs were inhibited when subjected to both clove (MIC: 250 to 500 µL/mL) and cinnamon (MIC: 62.5 µL/mL) EOs. Activity of both neat CO and CinO had no significant difference (p value ≥ 0.05). The identity of 3 SBPs (Strains: AR11E, AR12E and AR22E) were further confirmed by molecular identification (16SrRNA) and SEM revealed potential degradation of the bacterial cells with a reduction in count when treated with CinO and CO. Only one strain (AR22E) was positive for the papC gene. The prevalence of E. coli and strong-biofilm producers in retail chicken meat was not very high; however, the majority of the isolates were multi-drug resistant. Therefore, it is important to keep a tab on the prevalence of these commensal and pathogenic microorganisms in retail chicken meat since they are an exposure site close to the consumer. The use of alternative means like essential oils in poultry, meat and meat-products is a good strategy since they have proven efficacy against pathogenic E. coli.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
Animals
*Escherichia coli/drug effects/isolation & purification/physiology/genetics
Chickens/microbiology
*Oils, Volatile/pharmacology
*Meat/microbiology
*Cinnamomum zeylanicum/chemistry
*Anti-Bacterial Agents/pharmacology
*Drug Resistance, Multiple, Bacterial/drug effects
*Clove Oil/pharmacology
Microbial Sensitivity Tests
Syzygium/chemistry
Food Microbiology
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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.
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