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ESP: PubMed Auto Bibliography 14 Jul 2026 at 01:40 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: 2026-07-11
Development and in vitro evaluation of teicoplanin PEGylated (TEC-PEGylated) niosomes for antimicrobial and anti-biofilm activity against vancomycin-intermediate Staphylococcus aureus (VISA).
BMC biotechnology pii:10.1186/s12896-026-01201-6 [Epub ahead of print].
Vancomycin-intermediate Staphylococcus aureus (VISA) is a prominent pathogen in burn wound infections, mainly known for biofilm formation. Recently, infections associated with antibiotic-resistant VISA isolates have increasingly posed life-threatening risks. Accordingly, there is an urgent necessity to investigate and develop efficient strategies against the rapid spread of VISA strains in the healthcare system. In this research, a niosomal drug delivery system was developed using the thin-film hydration method and then surface‑modified with polyethylene glycol (PEG). Teicoplanin (TEC) was further incorporated into PEGylated niosome (TEC-PEGylated niosome), and key physicochemical properties, including encapsulation efficiency (EE %), drug release profile, particle size, surface zeta charge, morphology, polydispersity index (PDI), and 30-day stability were measured. The antimicrobial potential of TEC-PEGylated niosome against five VISA strains isolated from burn wounds was investigated by determining the minimum inhibitory/bactericidal concentrations (MIC, MBC) and the time-kill assay. Furthermore, the anti-biofilm properties of the synthesized niosomal formulation were evaluated with a microtiter-plate (MTP) method and compared to those of free drug. FE-SEM results revealed that the niosomal formulation had spherical morphology with an approximate size of 250 nm. Hydrodynamic size, surface zeta charge, and EE% of the formulated niosomes were found be 278.8 ± 5.0 nm, + 9.5 ± 3.4 mV, and 65.9% ± 1.6, respectively. Also, TEC-PEGylated niosome demonstrated a significantly improved antibacterial ability compared to free drug. Additionally, TEC-PEGylated niosome effectively inhibited the biofilm formation capacity in all VISA strains. It was concluded that synthesized niosomal system could be an effective drug delivery system owing to several advantageous characteristics, including sustained-release profiles, acceptable stability, and other desirable features. These properties enable PEGylated niosomes to effectively deliver a diverse array of antimicrobial agents, including TEC. This capability could present a promising novel strategy for addressing burn infections, particularly those caused by VISA strains.
Additional Links: PMID-42436457
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@article {pmid42436457,
year = {2026},
author = {Hemmati, J and Chegini, Z and Sedighi, I and Azizi, M and Shahraki, RZ and Chiani, M and Arabestani, MR},
title = {Development and in vitro evaluation of teicoplanin PEGylated (TEC-PEGylated) niosomes for antimicrobial and anti-biofilm activity against vancomycin-intermediate Staphylococcus aureus (VISA).},
journal = {BMC biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.1186/s12896-026-01201-6},
pmid = {42436457},
issn = {1472-6750},
support = {14030204782//The vice chancellor for research and technology, Hamadan university of medical sciences, Hamadan/Iran/ ; },
abstract = {Vancomycin-intermediate Staphylococcus aureus (VISA) is a prominent pathogen in burn wound infections, mainly known for biofilm formation. Recently, infections associated with antibiotic-resistant VISA isolates have increasingly posed life-threatening risks. Accordingly, there is an urgent necessity to investigate and develop efficient strategies against the rapid spread of VISA strains in the healthcare system. In this research, a niosomal drug delivery system was developed using the thin-film hydration method and then surface‑modified with polyethylene glycol (PEG). Teicoplanin (TEC) was further incorporated into PEGylated niosome (TEC-PEGylated niosome), and key physicochemical properties, including encapsulation efficiency (EE %), drug release profile, particle size, surface zeta charge, morphology, polydispersity index (PDI), and 30-day stability were measured. The antimicrobial potential of TEC-PEGylated niosome against five VISA strains isolated from burn wounds was investigated by determining the minimum inhibitory/bactericidal concentrations (MIC, MBC) and the time-kill assay. Furthermore, the anti-biofilm properties of the synthesized niosomal formulation were evaluated with a microtiter-plate (MTP) method and compared to those of free drug. FE-SEM results revealed that the niosomal formulation had spherical morphology with an approximate size of 250 nm. Hydrodynamic size, surface zeta charge, and EE% of the formulated niosomes were found be 278.8 ± 5.0 nm, + 9.5 ± 3.4 mV, and 65.9% ± 1.6, respectively. Also, TEC-PEGylated niosome demonstrated a significantly improved antibacterial ability compared to free drug. Additionally, TEC-PEGylated niosome effectively inhibited the biofilm formation capacity in all VISA strains. It was concluded that synthesized niosomal system could be an effective drug delivery system owing to several advantageous characteristics, including sustained-release profiles, acceptable stability, and other desirable features. These properties enable PEGylated niosomes to effectively deliver a diverse array of antimicrobial agents, including TEC. This capability could present a promising novel strategy for addressing burn infections, particularly those caused by VISA strains.},
}
RevDate: 2026-07-12
CmpDate: 2026-07-12
Lubricious anti-adhesive interface prevents friction, biofilm, and encrustation in long-term indwelling ureteral stents.
Materials today. Bio, 39:103405.
Ureteral stents are essential for relieving urinary obstruction and preserving renal function. However, long-term indwelling often induces friction-mediated urothelial irritation, bacterial colonization, and mineral encrustation, which impair urinary drainage and complicate stent removal. Here, we developed a friction-lowering urinary interface for defense against encrustation (FLUID) by integrating a silicone-based primer and lubricant layer into a fully microporous thermoplastic polyurethane framework. Unlike conventional slippery liquid-infused porous surfaces that retain lubricant primarily within surface microstructures, the fully microporous TPU framework serves as an internal lubricant reservoir throughout the stent wall, replenishing the lubricating interface under dynamic urinary conditions. Under sterile conditions the FLUID coating suppressed planktonic bacterial adhesion (E. coli, B. cereus, S. aureus; 72 h adhesion assay) by more than 94% relative to uncoated substrates. In a P. mirabilis-spiked 14-day mature biofilm model, biofilm-associated bacterial recovery from FLUID was modestly lower than from the commercialized comparators (Log R ≈ 0.10 and 0.14; approximately 21% and 28% reduction). In a porcine model, the coated stent reduced inflammatory activity and attenuated mineral accumulation after 4 weeks, with magnesium and calcium deposition decreased by 84.1% and 45.1%, respectively. After 8 weeks, scanning electron microscopy confirmed clean surfaces with patent side holes and minimal debris accumulation. Overall, the FLUID stent establishes a self-replenishing lubricant interface integrated throughout the microporous stent wall, enabling simultaneous mitigation of friction, early biofouling, and mineral deposition, and providing a clinically relevant proof-of-concept strategy for safer long-term urinary drainage that will require further preclinical validation prior to clinical adoption.
Additional Links: PMID-42436802
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@article {pmid42436802,
year = {2026},
author = {Jo, Y and Lee, Y and Bang, S and Son, K and Park, K and Kim, D and Kim, SA and Eom, S and Choi, I and Shin, SJ and Koo, KC and Seo, J},
title = {Lubricious anti-adhesive interface prevents friction, biofilm, and encrustation in long-term indwelling ureteral stents.},
journal = {Materials today. Bio},
volume = {39},
number = {},
pages = {103405},
pmid = {42436802},
issn = {2590-0064},
abstract = {Ureteral stents are essential for relieving urinary obstruction and preserving renal function. However, long-term indwelling often induces friction-mediated urothelial irritation, bacterial colonization, and mineral encrustation, which impair urinary drainage and complicate stent removal. Here, we developed a friction-lowering urinary interface for defense against encrustation (FLUID) by integrating a silicone-based primer and lubricant layer into a fully microporous thermoplastic polyurethane framework. Unlike conventional slippery liquid-infused porous surfaces that retain lubricant primarily within surface microstructures, the fully microporous TPU framework serves as an internal lubricant reservoir throughout the stent wall, replenishing the lubricating interface under dynamic urinary conditions. Under sterile conditions the FLUID coating suppressed planktonic bacterial adhesion (E. coli, B. cereus, S. aureus; 72 h adhesion assay) by more than 94% relative to uncoated substrates. In a P. mirabilis-spiked 14-day mature biofilm model, biofilm-associated bacterial recovery from FLUID was modestly lower than from the commercialized comparators (Log R ≈ 0.10 and 0.14; approximately 21% and 28% reduction). In a porcine model, the coated stent reduced inflammatory activity and attenuated mineral accumulation after 4 weeks, with magnesium and calcium deposition decreased by 84.1% and 45.1%, respectively. After 8 weeks, scanning electron microscopy confirmed clean surfaces with patent side holes and minimal debris accumulation. Overall, the FLUID stent establishes a self-replenishing lubricant interface integrated throughout the microporous stent wall, enabling simultaneous mitigation of friction, early biofouling, and mineral deposition, and providing a clinically relevant proof-of-concept strategy for safer long-term urinary drainage that will require further preclinical validation prior to clinical adoption.},
}
RevDate: 2026-07-12
Characterization of the biofilm landscape of Bacillus subtilis by spatial microproteomics.
Analytical and bioanalytical chemistry [Epub ahead of print].
Bulk proteomics has been demonstrated to differentiate subpopulations based on molecular phenotypes within bacterial colonies, yet advanced analyses by mass spectrometry imaging (MSI) hold even greater promise for the future. This technology can enable high-throughput spatial phenotyping that can directly visualize distinct components of various biomolecular mechanisms with high mass-resolving power in high spatial resolution analyses. Here, we applied MSI for intact protein imaging directly from thin cross-sections of a biofilm of Bacillus subtilis and after minimal preparation we detected more than 285 unique isotopic envelopes corresponding to unique proteoforms. We paired our MSI analyses with bulk top-down proteomics (TDP) to form extensive experimental libraries, which provided us with high confidence MSI annotations based upon isotopic matching to validated post-translational modifications (PTMs) and truncations. This joint application of MSI and TDP allowed us to describe the microscale spatial proteomic landscape within the B. subtilis biofilm. This study further demonstrated the feasibility of detecting differentiated subpopulations of cells through the identification of proteoforms of cannibalistic protein toxins as well as those involved in active sporulation to highly localized areas within the central and outermost periphery of the biofilm.
Additional Links: PMID-42437417
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@article {pmid42437417,
year = {2026},
author = {Zemaitis, KJ and Zhou, M and Yannarell, SM and Fulcher, JM and Bhattacharjee, A and Veličković, M and Degnan, DJ and Shank, EA and Anderton, CR and Kew, W and Paša-Tolić, L and Veličković, D},
title = {Characterization of the biofilm landscape of Bacillus subtilis by spatial microproteomics.},
journal = {Analytical and bioanalytical chemistry},
volume = {},
number = {},
pages = {},
pmid = {42437417},
issn = {1618-2650},
support = {51159//Environmental Molecular Sciences Laboratory/ ; },
abstract = {Bulk proteomics has been demonstrated to differentiate subpopulations based on molecular phenotypes within bacterial colonies, yet advanced analyses by mass spectrometry imaging (MSI) hold even greater promise for the future. This technology can enable high-throughput spatial phenotyping that can directly visualize distinct components of various biomolecular mechanisms with high mass-resolving power in high spatial resolution analyses. Here, we applied MSI for intact protein imaging directly from thin cross-sections of a biofilm of Bacillus subtilis and after minimal preparation we detected more than 285 unique isotopic envelopes corresponding to unique proteoforms. We paired our MSI analyses with bulk top-down proteomics (TDP) to form extensive experimental libraries, which provided us with high confidence MSI annotations based upon isotopic matching to validated post-translational modifications (PTMs) and truncations. This joint application of MSI and TDP allowed us to describe the microscale spatial proteomic landscape within the B. subtilis biofilm. This study further demonstrated the feasibility of detecting differentiated subpopulations of cells through the identification of proteoforms of cannibalistic protein toxins as well as those involved in active sporulation to highly localized areas within the central and outermost periphery of the biofilm.},
}
RevDate: 2026-07-12
Formulation development and optimization of sparfloxacin-loaded solid lipid nanoparticles integrated with microneedles for the treatment of biofilm-infected wounds.
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V pii:S0939-6411(26)00202-X [Epub ahead of print].
The efficient management of infected skin wounds is severely limited by the thick bacterial biofilm within the lesion, the intractable stratum corneum barrier of the perilesional skin, and the high toxicities of potent antibiotics. Sparfloxacin (SPFX) was withdrawn from the market due to its severe systemic side effects and UV-induced phototoxicity, while its severe hydrophobicity causes localized crystalline cytotoxicity upon topical application. To safely rejuvenate this potent drug, an integrated transdermal system combining photoshielding, SPFX-loaded solid lipid nanoparticles (SPFX-SLNs) with dissolving microneedles (MNs) was developed. This study primarily focuses on the systematic screening, formulation development, and optimization of SPFX-SLNs via Box-Behnken Design-Response Surface Methodology (BBD-RSM). The optimized nanocarriers exhibited a uniform size (86.85 ± 1.89 nm) and a two-fold higher antibacterial potency against Escherichia coli (E. coli) than free SPFX. Mechanistically, the solid lipid core locked SPFX in a safe amorphous state to preclude crystal-induced irritation, while functioning as a physical photoshield against UV activation. By depositing the nanomedicine exclusively into infected dermis, the MN platform minimized systemic drug exposure. In a rat model of E. coli-infected biofilm wounds, the formulated SPFX-SLNs MNs achieved over 50% (58.44%) wound closure within 3 days and near-complete re-epithelialization by day 11, and a 98.61% final closure rate by day 14. Ultimately, this work establishes a comprehensive formulation development strategy for a safety-enhanced, biofilm-penetrable nanomedicine-MN hybrid that successfully repurposes a clinically restricted antibiotic for advanced wound regeneration.
Additional Links: PMID-42437591
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PubMed:
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@article {pmid42437591,
year = {2026},
author = {Chen, J and Wu, W and Feng, B and Ning, M and Cai, Z and Zhang, Q and Du, L and Gao, Y},
title = {Formulation development and optimization of sparfloxacin-loaded solid lipid nanoparticles integrated with microneedles for the treatment of biofilm-infected wounds.},
journal = {European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V},
volume = {},
number = {},
pages = {115181},
doi = {10.1016/j.ejpb.2026.115181},
pmid = {42437591},
issn = {1873-3441},
abstract = {The efficient management of infected skin wounds is severely limited by the thick bacterial biofilm within the lesion, the intractable stratum corneum barrier of the perilesional skin, and the high toxicities of potent antibiotics. Sparfloxacin (SPFX) was withdrawn from the market due to its severe systemic side effects and UV-induced phototoxicity, while its severe hydrophobicity causes localized crystalline cytotoxicity upon topical application. To safely rejuvenate this potent drug, an integrated transdermal system combining photoshielding, SPFX-loaded solid lipid nanoparticles (SPFX-SLNs) with dissolving microneedles (MNs) was developed. This study primarily focuses on the systematic screening, formulation development, and optimization of SPFX-SLNs via Box-Behnken Design-Response Surface Methodology (BBD-RSM). The optimized nanocarriers exhibited a uniform size (86.85 ± 1.89 nm) and a two-fold higher antibacterial potency against Escherichia coli (E. coli) than free SPFX. Mechanistically, the solid lipid core locked SPFX in a safe amorphous state to preclude crystal-induced irritation, while functioning as a physical photoshield against UV activation. By depositing the nanomedicine exclusively into infected dermis, the MN platform minimized systemic drug exposure. In a rat model of E. coli-infected biofilm wounds, the formulated SPFX-SLNs MNs achieved over 50% (58.44%) wound closure within 3 days and near-complete re-epithelialization by day 11, and a 98.61% final closure rate by day 14. Ultimately, this work establishes a comprehensive formulation development strategy for a safety-enhanced, biofilm-penetrable nanomedicine-MN hybrid that successfully repurposes a clinically restricted antibiotic for advanced wound regeneration.},
}
RevDate: 2026-07-11
Mechanical determinants of bacterial collective behavior: from active turbulence to early biofilm organization.
Critical reviews in microbiology [Epub ahead of print].
During early colonization, motile bacteria can shift from independent swimming to coordinated collective states shaped by environmental mechanics, with consequences for subsequent biofilm development and tolerance. This critical review integrates active matter physics with biofilm microbiology to evaluate a working model in which viscoelasticity, mechanotransduction, and geometric confinement form a synergistic triad of mechanical determinants that may bias communities toward tolerant states before matrix immobilization dominates. Community mechanics remains underexplored because established non-genetic mechanisms explain only part of the striking gap between planktonic killing and biofilm tolerance. Within this model, viscoelasticity of host fluids and nascent matrix, captured by an effective Deborah number, may extend hydrodynamic coupling between cells. Surface mechanotransduction can convert flagellar or pilus load into rapid cyclic di-GMP signaling, while geometric confinement in tissues and device lumens can restrict collective states available to bacteria. Together, these factors motivate testable links among viscoelasticity, bacterial density, and velocity correlation length. Current evidence derives mainly from simplified in vitro systems, and validation in three-dimensional polymicrobial clinical materials remains limited. The review highlights priorities and translational hypotheses, including motion phenotyping, rheology-modifying adjuvants, and geometry-based disruption as complements to antimicrobial therapy.
Additional Links: PMID-42434857
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PubMed:
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@article {pmid42434857,
year = {2026},
author = {Patil, N},
title = {Mechanical determinants of bacterial collective behavior: from active turbulence to early biofilm organization.},
journal = {Critical reviews in microbiology},
volume = {},
number = {},
pages = {1-19},
doi = {10.1080/1040841X.2026.2698959},
pmid = {42434857},
issn = {1549-7828},
abstract = {During early colonization, motile bacteria can shift from independent swimming to coordinated collective states shaped by environmental mechanics, with consequences for subsequent biofilm development and tolerance. This critical review integrates active matter physics with biofilm microbiology to evaluate a working model in which viscoelasticity, mechanotransduction, and geometric confinement form a synergistic triad of mechanical determinants that may bias communities toward tolerant states before matrix immobilization dominates. Community mechanics remains underexplored because established non-genetic mechanisms explain only part of the striking gap between planktonic killing and biofilm tolerance. Within this model, viscoelasticity of host fluids and nascent matrix, captured by an effective Deborah number, may extend hydrodynamic coupling between cells. Surface mechanotransduction can convert flagellar or pilus load into rapid cyclic di-GMP signaling, while geometric confinement in tissues and device lumens can restrict collective states available to bacteria. Together, these factors motivate testable links among viscoelasticity, bacterial density, and velocity correlation length. Current evidence derives mainly from simplified in vitro systems, and validation in three-dimensional polymicrobial clinical materials remains limited. The review highlights priorities and translational hypotheses, including motion phenotyping, rheology-modifying adjuvants, and geometry-based disruption as complements to antimicrobial therapy.},
}
RevDate: 2026-07-11
Substrate Carbon Controls Regional Divergence of Wetland Biofilm Carbon Sinks under Climate Warming.
Environmental science & technology [Epub ahead of print].
Microbial biofilms at soil-water interfaces mediate carbon exchange between soils and the atmosphere, yet whether substrate state alters their climate sensitivity remains poorly understood. Here, we analyzed 1080 rice-paddy sites across 26 regions of China to test whether soil organic carbon (SOC) regulates periphytic biofilm organic carbon (PB-TOC) responses to warming. SOC emerged as the dominant predictor of PB-TOC and showed a statistically supported threshold at ∼20 g kg[-1]. Below this threshold, PB-TOC increased with SOC and was positively associated with mean annual temperature and precipitation, consistent with a substrate-limited compensatory response. Above the threshold, PB-TOC approached saturation, and climate associations became negative, indicating greater vulnerability of carbon-rich interfaces. CMIP6-based projections suggest that under SSP5-8.5, China's paddy-interface biofilm carbon pool could decline by about 0.70 Tg C by 2100, driven mainly by 4.5-6.8% losses in high-SOC regions that are only partly offset by modest gains in low-SOC regions (0.8-1.5%). These findings indicate that wetland climate responses are state-dependent and that substrate thresholds should be incorporated into carbon-climate assessments.
Additional Links: PMID-42434941
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@article {pmid42434941,
year = {2026},
author = {Wang, K and Sun, P and Liu, J and Xu, Y and Lu, W and Wu, Y and Smith, P},
title = {Substrate Carbon Controls Regional Divergence of Wetland Biofilm Carbon Sinks under Climate Warming.},
journal = {Environmental science & technology},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.est.6c03534},
pmid = {42434941},
issn = {1520-5851},
abstract = {Microbial biofilms at soil-water interfaces mediate carbon exchange between soils and the atmosphere, yet whether substrate state alters their climate sensitivity remains poorly understood. Here, we analyzed 1080 rice-paddy sites across 26 regions of China to test whether soil organic carbon (SOC) regulates periphytic biofilm organic carbon (PB-TOC) responses to warming. SOC emerged as the dominant predictor of PB-TOC and showed a statistically supported threshold at ∼20 g kg[-1]. Below this threshold, PB-TOC increased with SOC and was positively associated with mean annual temperature and precipitation, consistent with a substrate-limited compensatory response. Above the threshold, PB-TOC approached saturation, and climate associations became negative, indicating greater vulnerability of carbon-rich interfaces. CMIP6-based projections suggest that under SSP5-8.5, China's paddy-interface biofilm carbon pool could decline by about 0.70 Tg C by 2100, driven mainly by 4.5-6.8% losses in high-SOC regions that are only partly offset by modest gains in low-SOC regions (0.8-1.5%). These findings indicate that wetland climate responses are state-dependent and that substrate thresholds should be incorporated into carbon-climate assessments.},
}
RevDate: 2026-07-11
Biofilm mediated arsenic migration and transformation in groundwater under the influence of dissolved organic matter.
Journal of hazardous materials, 514:142951 pii:S0304-3894(26)01931-X [Epub ahead of print].
Biofilms, ubiquitous in a variety of aquatic and terrestrial ecosystems, strongly regulate arsenic (As) cycle. Dissolved organic matter (DOM) can stimulate the development and activity of microbial communities, thus enhancing arsenic biogeochemical processes. However, how DOM regulates groundwater biofilms to drive arsenic migration and transformation remains unclear. Incubation experiments were integrated with biofilm characterizations, 16S rRNA amplicon sequencing, qPCR, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to explore the behaviors and potential mechanisms of arsenic under the mediation of biofilms and fulvic acid (FA), a representative molecule of DOM in groundwater. FA induced a 7.5‑fold increase in EPS secretion, characterized by a marked enrichment of α‑configuration polysaccharides, which provided additional binding sites and steric hindrance, thereby enhancing arsenic adsorption by 21.98%. Biofilms enhanced As(III) oxidation potentially via aoxA/B, regardless of FA presence. Subsequent As(V) reduction was mainly driven by FA‑enriched N and S cycling bacteria in biofilms. The reductive products of these bacteria, especially NH4[+], enhanced arrA, thereby promoting arsenate reduction. FA-Ca-As ternary complexes likely further contributed to arsenic sequestration. Additionally, the electron shuttle function of FA potentially accelerated As(V)/As(III) inter-conversion. To the best of our knowledge, this study initially revealed the importance of DOM and biofilms on groundwater arsenic fate, and provided new insights into environmental arsenic cycles.
Additional Links: PMID-42435688
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PubMed:
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@article {pmid42435688,
year = {2026},
author = {Li, H and Li, C and Luo, X and Gao, X and Liu, S and Li, S and Wang, X and Zhu, M and Li, J and Cavalca, L},
title = {Biofilm mediated arsenic migration and transformation in groundwater under the influence of dissolved organic matter.},
journal = {Journal of hazardous materials},
volume = {514},
number = {},
pages = {142951},
doi = {10.1016/j.jhazmat.2026.142951},
pmid = {42435688},
issn = {1873-3336},
abstract = {Biofilms, ubiquitous in a variety of aquatic and terrestrial ecosystems, strongly regulate arsenic (As) cycle. Dissolved organic matter (DOM) can stimulate the development and activity of microbial communities, thus enhancing arsenic biogeochemical processes. However, how DOM regulates groundwater biofilms to drive arsenic migration and transformation remains unclear. Incubation experiments were integrated with biofilm characterizations, 16S rRNA amplicon sequencing, qPCR, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to explore the behaviors and potential mechanisms of arsenic under the mediation of biofilms and fulvic acid (FA), a representative molecule of DOM in groundwater. FA induced a 7.5‑fold increase in EPS secretion, characterized by a marked enrichment of α‑configuration polysaccharides, which provided additional binding sites and steric hindrance, thereby enhancing arsenic adsorption by 21.98%. Biofilms enhanced As(III) oxidation potentially via aoxA/B, regardless of FA presence. Subsequent As(V) reduction was mainly driven by FA‑enriched N and S cycling bacteria in biofilms. The reductive products of these bacteria, especially NH4[+], enhanced arrA, thereby promoting arsenate reduction. FA-Ca-As ternary complexes likely further contributed to arsenic sequestration. Additionally, the electron shuttle function of FA potentially accelerated As(V)/As(III) inter-conversion. To the best of our knowledge, this study initially revealed the importance of DOM and biofilms on groundwater arsenic fate, and provided new insights into environmental arsenic cycles.},
}
RevDate: 2026-07-10
CmpDate: 2026-07-10
Molecular insights into sub-inhibitory ceftriaxone-mediated modulation of Pseudomonas aeruginosa biofilm architecture, quorum sensing networks, and antibiotic-target docking interactions.
Polimery w medycynie, 56(1):65-74.
BACKGROUND: Pseudomonas aeruginosa biofilm polymer matrix formation contributes to antibiotic tolerance. The antibiofilm effects of sub-minimum inhibitory concentrations (MICs) of ceftriaxone (CTX), the molecular mechanisms by which these sub-MICs modulate biofilm polymer production and quorum sensing (QS), and the binding interactions of CTX with key biofilm regulatory proteins (LasR and RhlR QS receptors) have not been previously investigated.
OBJECTIVES: To determine the role of sub-MIC CTX in regulating biofilm polymer matrix formation, bacterial adhesion, QS gene expression (rhlR and lasR), and to perform molecular docking analysis of CTX interactions with LasR and RhlR QS receptor proteins and biofilm EPS polymer-associated targets.
MATERIAL AND METHODS: MICs and biofilm formation were determined. The effects of CTX sub-MICs on biofilm formation, adhesion to mouse bladder epithelial cells (BECs), and QS gene expression (rhlR and lasR, by qRT-PCR) were assessed. In silico molecular docking of CTX against the ligand-binding domains of LasR (PDB: 2UV0) and RhlR (PDB: 3T5K) was performed using AutoDock Vina. Interaction fingerprinting with biofilm EPS polymer-associated enzymes (AlgD and PelB) was also performed.
RESULTS: CTX sub-MICs regulated biofilm formation in an isolate-dependent manner, reduced P. aeruginosa adhesion to mouse BECs, and downregulated the rhlR and lasR genes in a concentration-dependent manner. Molecular docking revealed that CTX binds favorably within the ligand-binding pockets of LasR (-8.3 kcal/mol) and RhlR (-7.1 kcal/mol) via hydrogen bonding and hydrophobic interactions, suggesting competitive interference with QS autoinducer binding. CTX also exhibited affinity for AlgD (-7.6 kcal/mol), a key enzyme in alginate polymer biosynthesis.
CONCLUSIONS: CTX sub-MICs modulate biofilm EPS polymer matrix formation and epithelial adhesion by downregulating QS regulatory genes. lasR was more responsive to CTX sub-MIC stress than rhlR. Molecular docking supports a direct molecular interaction mechanism through which CTX may interfere with QS receptor signaling and alginate polymer biosynthesis, providing a structural basis for its antibiofilm activity at sub-inhibitory concentrations.
Additional Links: PMID-42427189
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PubMed:
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@article {pmid42427189,
year = {2026},
author = {Jaber, NA and Ghafil, JA},
title = {Molecular insights into sub-inhibitory ceftriaxone-mediated modulation of Pseudomonas aeruginosa biofilm architecture, quorum sensing networks, and antibiotic-target docking interactions.},
journal = {Polimery w medycynie},
volume = {56},
number = {1},
pages = {65-74},
doi = {10.17219/pim/224596},
pmid = {42427189},
issn = {0370-0747},
mesh = {*Quorum Sensing/drug effects ; *Pseudomonas aeruginosa/drug effects/physiology ; *Biofilms/drug effects ; Molecular Docking Simulation ; *Anti-Bacterial Agents/pharmacology ; Animals ; Bacterial Proteins/metabolism/genetics ; Mice ; Trans-Activators/metabolism/genetics ; *Ceftriaxone/pharmacology ; Microbial Sensitivity Tests ; Bacterial Adhesion/drug effects ; },
abstract = {BACKGROUND: Pseudomonas aeruginosa biofilm polymer matrix formation contributes to antibiotic tolerance. The antibiofilm effects of sub-minimum inhibitory concentrations (MICs) of ceftriaxone (CTX), the molecular mechanisms by which these sub-MICs modulate biofilm polymer production and quorum sensing (QS), and the binding interactions of CTX with key biofilm regulatory proteins (LasR and RhlR QS receptors) have not been previously investigated.
OBJECTIVES: To determine the role of sub-MIC CTX in regulating biofilm polymer matrix formation, bacterial adhesion, QS gene expression (rhlR and lasR), and to perform molecular docking analysis of CTX interactions with LasR and RhlR QS receptor proteins and biofilm EPS polymer-associated targets.
MATERIAL AND METHODS: MICs and biofilm formation were determined. The effects of CTX sub-MICs on biofilm formation, adhesion to mouse bladder epithelial cells (BECs), and QS gene expression (rhlR and lasR, by qRT-PCR) were assessed. In silico molecular docking of CTX against the ligand-binding domains of LasR (PDB: 2UV0) and RhlR (PDB: 3T5K) was performed using AutoDock Vina. Interaction fingerprinting with biofilm EPS polymer-associated enzymes (AlgD and PelB) was also performed.
RESULTS: CTX sub-MICs regulated biofilm formation in an isolate-dependent manner, reduced P. aeruginosa adhesion to mouse BECs, and downregulated the rhlR and lasR genes in a concentration-dependent manner. Molecular docking revealed that CTX binds favorably within the ligand-binding pockets of LasR (-8.3 kcal/mol) and RhlR (-7.1 kcal/mol) via hydrogen bonding and hydrophobic interactions, suggesting competitive interference with QS autoinducer binding. CTX also exhibited affinity for AlgD (-7.6 kcal/mol), a key enzyme in alginate polymer biosynthesis.
CONCLUSIONS: CTX sub-MICs modulate biofilm EPS polymer matrix formation and epithelial adhesion by downregulating QS regulatory genes. lasR was more responsive to CTX sub-MIC stress than rhlR. Molecular docking supports a direct molecular interaction mechanism through which CTX may interfere with QS receptor signaling and alginate polymer biosynthesis, providing a structural basis for its antibiofilm activity at sub-inhibitory concentrations.},
}
MeSH Terms:
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*Quorum Sensing/drug effects
*Pseudomonas aeruginosa/drug effects/physiology
*Biofilms/drug effects
Molecular Docking Simulation
*Anti-Bacterial Agents/pharmacology
Animals
Bacterial Proteins/metabolism/genetics
Mice
Trans-Activators/metabolism/genetics
*Ceftriaxone/pharmacology
Microbial Sensitivity Tests
Bacterial Adhesion/drug effects
RevDate: 2026-07-10
Deletion of flgL in Mesorhizobium ciceri USDA 3378 weakened competitive nodulation ability by reducing flagellum formation, biofilm formation, and extracellular polysaccharide secretion.
Applied and environmental microbiology [Epub ahead of print].
Mesorhizobium ciceri USDA 3378 has a competitive advantage over the indigenous Mesorhizobium muleiense CCBAU 83963 in nodulating chickpea (Cicer arietinum L.) in newly introduced planting areas in China. The underlying mechanisms for this dominance remain unclear. A comparison of the genomes of USDA 3378 and CCBAU 83963 revealed significantly more genes involved in flagellum production and cell movement in USDA 3378. USDA 3378 produced flagella, but CCBAU 83963 did not and showed lower motility, biofilm production, and extracellular polysaccharide secretion than USDA 3378. Transcriptome analysis of USDA 3378 under simulated symbiotic versus non-symbiotic conditions showed strong induction of nodulation genes and a broader transcriptional response among genes assigned to quorum sensing, chemotaxis, and flagellar assembly, with flgL (encoding a flagellar hook-associated family protein) being the only upregulated flagellar structural gene detected. A flgL mutant strain based on USDA 3378 (ΔflgL-3378) showed similar growth to USDA 3378 but was unable to produce flagella and exhibited concomitant reductions in motility, biofilm production, and extracellular polysaccharide secretion. Nodule occupancy by USDA 3378 was 100% when co-inoculated with CCBAU 83963. In contrast, nodule occupancy by ΔflgL-3378 was significantly reduced to 39.88% when co-inoculated with the wild-type USDA 3378. However, when co-inoculated with the indigenous strain CCBAU 83963, ΔflgL-3378 still showed a dominant occupancy of 82.8%. Transcriptome analysis of ΔflgL-3378 under the same comparison showed continued induction of nodulation genes and several flagellar system genes, an altered quorum-sensing-associated response, and no detectable chemotaxis-related differentially expressed genes. We conclude that flgL and flagella act as important contributors to the superior competitive nodulation ability of M. ciceri USDA 3378 over M. muleiense in chickpea, although other intrinsic genomic advantages likely contribute to its basal competitivenessIMPORTANCEChickpea is an important legume crop that depends on symbiotic rhizobia for biological nitrogen fixation. In newly introduced chickpea-growing regions of China, Mesorhizobium ciceri USDA 3378 shows a strong competitive advantage in nodulating chickpea compared with the indigenous strain Mesorhizobium muleiense CCBAU 83963, but the mechanisms underlying this advantage remain unclear. This study identifies the flagellar hook-associated gene flgL as an important contributor to the competitive nodulation ability of USDA 3378. Deletion of flgL abolished flagellum formation and reduced motility, biofilm formation, extracellular polysaccharide production, and competitive nodulation ability. However, the ΔflgL mutant still retained higher competitiveness than CCBAU 83963, indicating that additional motility-independent traits also contribute to the basal competitiveness of USDA 3378. These findings improve our understanding of the bacterial traits that influence rhizobial competitiveness and may help guide the development of more effective chickpea inoculants for diverse agricultural environments.
Additional Links: PMID-42429764
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PubMed:
Citation:
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@article {pmid42429764,
year = {2026},
author = {Chen, K and Zhu, C and Li, K and Hao, H and Zhang, K and Li, Y and Andrews, M and Zhang, J},
title = {Deletion of flgL in Mesorhizobium ciceri USDA 3378 weakened competitive nodulation ability by reducing flagellum formation, biofilm formation, and extracellular polysaccharide secretion.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0093126},
doi = {10.1128/aem.00931-26},
pmid = {42429764},
issn = {1098-5336},
abstract = {Mesorhizobium ciceri USDA 3378 has a competitive advantage over the indigenous Mesorhizobium muleiense CCBAU 83963 in nodulating chickpea (Cicer arietinum L.) in newly introduced planting areas in China. The underlying mechanisms for this dominance remain unclear. A comparison of the genomes of USDA 3378 and CCBAU 83963 revealed significantly more genes involved in flagellum production and cell movement in USDA 3378. USDA 3378 produced flagella, but CCBAU 83963 did not and showed lower motility, biofilm production, and extracellular polysaccharide secretion than USDA 3378. Transcriptome analysis of USDA 3378 under simulated symbiotic versus non-symbiotic conditions showed strong induction of nodulation genes and a broader transcriptional response among genes assigned to quorum sensing, chemotaxis, and flagellar assembly, with flgL (encoding a flagellar hook-associated family protein) being the only upregulated flagellar structural gene detected. A flgL mutant strain based on USDA 3378 (ΔflgL-3378) showed similar growth to USDA 3378 but was unable to produce flagella and exhibited concomitant reductions in motility, biofilm production, and extracellular polysaccharide secretion. Nodule occupancy by USDA 3378 was 100% when co-inoculated with CCBAU 83963. In contrast, nodule occupancy by ΔflgL-3378 was significantly reduced to 39.88% when co-inoculated with the wild-type USDA 3378. However, when co-inoculated with the indigenous strain CCBAU 83963, ΔflgL-3378 still showed a dominant occupancy of 82.8%. Transcriptome analysis of ΔflgL-3378 under the same comparison showed continued induction of nodulation genes and several flagellar system genes, an altered quorum-sensing-associated response, and no detectable chemotaxis-related differentially expressed genes. We conclude that flgL and flagella act as important contributors to the superior competitive nodulation ability of M. ciceri USDA 3378 over M. muleiense in chickpea, although other intrinsic genomic advantages likely contribute to its basal competitivenessIMPORTANCEChickpea is an important legume crop that depends on symbiotic rhizobia for biological nitrogen fixation. In newly introduced chickpea-growing regions of China, Mesorhizobium ciceri USDA 3378 shows a strong competitive advantage in nodulating chickpea compared with the indigenous strain Mesorhizobium muleiense CCBAU 83963, but the mechanisms underlying this advantage remain unclear. This study identifies the flagellar hook-associated gene flgL as an important contributor to the competitive nodulation ability of USDA 3378. Deletion of flgL abolished flagellum formation and reduced motility, biofilm formation, extracellular polysaccharide production, and competitive nodulation ability. However, the ΔflgL mutant still retained higher competitiveness than CCBAU 83963, indicating that additional motility-independent traits also contribute to the basal competitiveness of USDA 3378. These findings improve our understanding of the bacterial traits that influence rhizobial competitiveness and may help guide the development of more effective chickpea inoculants for diverse agricultural environments.},
}
RevDate: 2026-07-10
Gramine disrupts quorum sensing and biofilm formation of Pseudomonas aeruginosa: An integrated experimental and computational analysis.
Folia microbiologica [Epub ahead of print].
Bacterial resistance towards antibiotics has become a major problem worldwide. Bacteria become more resistant towards available antibiotics due to quorum sensing and biofilm formation. Alkaloids exhibited potential anti-bacterial activity. In the present study, the anti-quorum sensing and antibiofilm abilities of gramine (GRM) are evaluated. Gramine, an alkaloid already reported for several biological activities includes antiviral, anti-bacterial and antitumor was evaluated for its inhibition of quorum sensing and biofilm mediated virulence in Pseudomonas aeruginosa. The anti-infective effect of GRM using Caenorhabditis elegans and Galleria mellonella models was determined. Gramine reduced violacein production by 78% in C. violaceum. GRM inhibit 84% biofilm formation in P. aeruginosa. Notably, GRM inhibits several virulence factors (Pyocyanin, Pyoverdine, HCN, Alginate and several others) of P. aeruginosa. Further validation by qRT-PCR showed that GRM significantly downregulated several virulence associated genes. In silico studies revealed the GRM interaction with the three main quorum sensing signal receptors (LasR, RhlR and PqsR) of P. aeruginosa. In vivo anti-infective experiments suggested GRM's protective effect in C. elegans and G. mellonella infection models. Our results suggests that GRM as an effective anti-biofilm and anti-infective agent.
Additional Links: PMID-42429849
PubMed:
Citation:
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@article {pmid42429849,
year = {2026},
author = {Pakhira, P and Ranganathan, S and Parasuraman, P and Lee, JK and Suchiang, K and Ramatchandirane, M and Busi, S},
title = {Gramine disrupts quorum sensing and biofilm formation of Pseudomonas aeruginosa: An integrated experimental and computational analysis.},
journal = {Folia microbiologica},
volume = {},
number = {},
pages = {},
pmid = {42429849},
issn = {1874-9356},
abstract = {Bacterial resistance towards antibiotics has become a major problem worldwide. Bacteria become more resistant towards available antibiotics due to quorum sensing and biofilm formation. Alkaloids exhibited potential anti-bacterial activity. In the present study, the anti-quorum sensing and antibiofilm abilities of gramine (GRM) are evaluated. Gramine, an alkaloid already reported for several biological activities includes antiviral, anti-bacterial and antitumor was evaluated for its inhibition of quorum sensing and biofilm mediated virulence in Pseudomonas aeruginosa. The anti-infective effect of GRM using Caenorhabditis elegans and Galleria mellonella models was determined. Gramine reduced violacein production by 78% in C. violaceum. GRM inhibit 84% biofilm formation in P. aeruginosa. Notably, GRM inhibits several virulence factors (Pyocyanin, Pyoverdine, HCN, Alginate and several others) of P. aeruginosa. Further validation by qRT-PCR showed that GRM significantly downregulated several virulence associated genes. In silico studies revealed the GRM interaction with the three main quorum sensing signal receptors (LasR, RhlR and PqsR) of P. aeruginosa. In vivo anti-infective experiments suggested GRM's protective effect in C. elegans and G. mellonella infection models. Our results suggests that GRM as an effective anti-biofilm and anti-infective agent.},
}
RevDate: 2026-07-10
High-quality metagenome-assembled genome sequences of Bacteroidota and Pseudomonadota bacteria, assembled from a manganese(II)-oxidizing biofilm reactor.
Microbiology resource announcements [Epub ahead of print].
We report five high-quality, potentially novel metagenome-assembled genomes (MAGs) recovered from a manganese(II)-oxidizing biofilm reactor. Affiliated with Bacteroidota and Pseudomonadota, these MAGs provide a genomic basis for understanding the ecology and metabolic potential of Mn(II)-oxidizing systems and represent a valuable resource for future functional studies of biofilm-mediated metal cycling.
Additional Links: PMID-42430136
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PubMed:
Citation:
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@article {pmid42430136,
year = {2026},
author = {Aoki, M and Wakui, N and Hayashi, K and Syutsubo, K},
title = {High-quality metagenome-assembled genome sequences of Bacteroidota and Pseudomonadota bacteria, assembled from a manganese(II)-oxidizing biofilm reactor.},
journal = {Microbiology resource announcements},
volume = {},
number = {},
pages = {e0058826},
doi = {10.1128/mra.00588-26},
pmid = {42430136},
issn = {2576-098X},
abstract = {We report five high-quality, potentially novel metagenome-assembled genomes (MAGs) recovered from a manganese(II)-oxidizing biofilm reactor. Affiliated with Bacteroidota and Pseudomonadota, these MAGs provide a genomic basis for understanding the ecology and metabolic potential of Mn(II)-oxidizing systems and represent a valuable resource for future functional studies of biofilm-mediated metal cycling.},
}
RevDate: 2026-07-10
Characterization of bacteriophage JD929 targeting Staphylococcus aureus from chronic otitis media and its ability to inhibit biofilm.
Microbiological research, 312:128620 pii:S0944-5013(26)00184-9 [Epub ahead of print].
BACKGROUND: Staphylococcus aureus (S. aureus) is a key pathogen involved in chronic suppurative otitis media (CSOM). Antibiotic resistance and biofilm formation complicate CSOM treatment. Therefore, alternative therapies are urgently needed. Bacteriophage therapy, which specifically targets and destroys methicillin-resistant S. aureus (MRSA) and degrades biofilms, presents a promising option.
METHODS: In this study, a lytic bacteriophage targeting S. aureus was isolated and named JD929. Its biological properties were analyzed, including its stability across different pH levels and temperatures, host range, and growth kinetics. Whole-genome sequencing and bioinformatics analyses were performed for taxonomic classification. Additionally, structural prediction and homology analysis of the tail protein (ORF8) were conducted using AlphaFold. The antibiofilm activity of JD929 against CSOM-associated S. aureus was also assessed.
RESULTS: JD929 demonstrated high stability across a broad range of pH levels and temperatures and exhibited a distinct host spectrum from that of phage SLPW. One-step growth analysis showed a latent period of 30 min and a burst size of 156 PFU per cell. Genomic analysis identified JD929 as a member of the Rountreeviridae family. Structural prediction revealed that the tail protein has unique sequence and structural features, indicating a potential role in host recognition. Functionally, JD929 significantly inhibited biofilm formation and disrupted mature biofilms of CSOM-associated S. aureus.
CONCLUSIONS: The newly isolated bacteriophage JD929 exhibits beneficial biological properties and strong, strain-specific antibiofilm activity, highlighting its potential as an alternative treatment for CSOM-associated S. aureus infections.
Additional Links: PMID-42430968
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PubMed:
Citation:
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@article {pmid42430968,
year = {2026},
author = {He, J and Xu, D and Zhong, L and Liao, H and Wang, J and Wang, Z and Feng, T and Pan, S and Cui, Z},
title = {Characterization of bacteriophage JD929 targeting Staphylococcus aureus from chronic otitis media and its ability to inhibit biofilm.},
journal = {Microbiological research},
volume = {312},
number = {},
pages = {128620},
doi = {10.1016/j.micres.2026.128620},
pmid = {42430968},
issn = {1618-0623},
abstract = {BACKGROUND: Staphylococcus aureus (S. aureus) is a key pathogen involved in chronic suppurative otitis media (CSOM). Antibiotic resistance and biofilm formation complicate CSOM treatment. Therefore, alternative therapies are urgently needed. Bacteriophage therapy, which specifically targets and destroys methicillin-resistant S. aureus (MRSA) and degrades biofilms, presents a promising option.
METHODS: In this study, a lytic bacteriophage targeting S. aureus was isolated and named JD929. Its biological properties were analyzed, including its stability across different pH levels and temperatures, host range, and growth kinetics. Whole-genome sequencing and bioinformatics analyses were performed for taxonomic classification. Additionally, structural prediction and homology analysis of the tail protein (ORF8) were conducted using AlphaFold. The antibiofilm activity of JD929 against CSOM-associated S. aureus was also assessed.
RESULTS: JD929 demonstrated high stability across a broad range of pH levels and temperatures and exhibited a distinct host spectrum from that of phage SLPW. One-step growth analysis showed a latent period of 30 min and a burst size of 156 PFU per cell. Genomic analysis identified JD929 as a member of the Rountreeviridae family. Structural prediction revealed that the tail protein has unique sequence and structural features, indicating a potential role in host recognition. Functionally, JD929 significantly inhibited biofilm formation and disrupted mature biofilms of CSOM-associated S. aureus.
CONCLUSIONS: The newly isolated bacteriophage JD929 exhibits beneficial biological properties and strong, strain-specific antibiofilm activity, highlighting its potential as an alternative treatment for CSOM-associated S. aureus infections.},
}
RevDate: 2026-07-10
Hybrid cellular automaton-based model for quorum sensing-controlled biofilm evolution.
Computers in biology and medicine, 213:111852 pii:S0010-4825(26)00416-6 [Epub ahead of print].
Computational modeling and in silico studies are critical for understanding how the spatial organization of biofilms contributes to antimicrobial tolerance and persistence. The paper presents a novel hybrid computational framework for the discrete-in-space dynamical modeling of bacterial biofilms. The approach combines a cellular automaton, which generates naturalistic biofilm morphology on a hexagonal lattice, with discrete analogues of reaction-diffusion equations governing the distribution of nutrients and signaling molecules. This design incorporates a quorum sensing feedback mechanism that links local signaling molecule concentration to biofilm spreading. The simulation system was developed in C# on the Unity platform, and the source code together with a Windows executable release was deposited on Zenodo. The biological plausibility of the simulated AHL and population dynamics was assessed through a semi-qualitative comparison with published experimental observations. The results reproduce distinct growth regimes ranging from sparse, branched colonies to compact biofilms with continuous fronts. A two-parameter analysis reveals a curved transition boundary in the nutrient-threshold plane, demonstrating that the effective quorum sensing activation threshold depends on nutrient availability. The qualitative comparison shows that the model can generate a biologically plausible transient AHL profile, including signal accumulation, formation of a maximum, and subsequent decrease, together with saturating population dynamics. This comparison is not intended as quantitative validation of absolute timing, concentration, or the detailed biochemical mechanism of AHL removal. These results support the proposed approach as a mechanistic tool for studying how quorum sensing and nutrient limitation jointly shape biofilm morphology. By providing an interpretable mechanistic simulation framework with explicit state variables, transition operators, and experimentally comparable outputs, the model establishes a basis for future AI-assisted workflows for diffusion-solver acceleration and automated parameter calibration.
Additional Links: PMID-42431014
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PubMed:
Citation:
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@article {pmid42431014,
year = {2026},
author = {Sarukhanian, S and Kuttler, C and Maslovskaya, A},
title = {Hybrid cellular automaton-based model for quorum sensing-controlled biofilm evolution.},
journal = {Computers in biology and medicine},
volume = {213},
number = {},
pages = {111852},
doi = {10.1016/j.compbiomed.2026.111852},
pmid = {42431014},
issn = {1879-0534},
abstract = {Computational modeling and in silico studies are critical for understanding how the spatial organization of biofilms contributes to antimicrobial tolerance and persistence. The paper presents a novel hybrid computational framework for the discrete-in-space dynamical modeling of bacterial biofilms. The approach combines a cellular automaton, which generates naturalistic biofilm morphology on a hexagonal lattice, with discrete analogues of reaction-diffusion equations governing the distribution of nutrients and signaling molecules. This design incorporates a quorum sensing feedback mechanism that links local signaling molecule concentration to biofilm spreading. The simulation system was developed in C# on the Unity platform, and the source code together with a Windows executable release was deposited on Zenodo. The biological plausibility of the simulated AHL and population dynamics was assessed through a semi-qualitative comparison with published experimental observations. The results reproduce distinct growth regimes ranging from sparse, branched colonies to compact biofilms with continuous fronts. A two-parameter analysis reveals a curved transition boundary in the nutrient-threshold plane, demonstrating that the effective quorum sensing activation threshold depends on nutrient availability. The qualitative comparison shows that the model can generate a biologically plausible transient AHL profile, including signal accumulation, formation of a maximum, and subsequent decrease, together with saturating population dynamics. This comparison is not intended as quantitative validation of absolute timing, concentration, or the detailed biochemical mechanism of AHL removal. These results support the proposed approach as a mechanistic tool for studying how quorum sensing and nutrient limitation jointly shape biofilm morphology. By providing an interpretable mechanistic simulation framework with explicit state variables, transition operators, and experimentally comparable outputs, the model establishes a basis for future AI-assisted workflows for diffusion-solver acceleration and automated parameter calibration.},
}
RevDate: 2026-07-10
Arginine attenuates microbiologically influenced corrosion of Ti in Candida albicans-Streptococcus oralis cross-kingdom biofilms through pH buffering and biofilm suppression.
Bioelectrochemistry (Amsterdam, Netherlands), 172:109378 pii:S1567-5394(26)00164-7 [Epub ahead of print].
This study investigates the effect of arginine on Ti corrosion caused by a Candida albicans (C. albicans) and Streptococcus oralis (S. oralis) cross-border biofilm. Electrochemical analyses, surface morphologies and corrosion products analysis were conducted to evaluate the effects of arginine on biofilm-associated corrosion behavior. The results showed that supplementation with 0.25% arginine significantly reduced microbial colonization and biofilm thickness on Ti surfaces, particularly in the cross-border biofilm system. In situ pH analysis further demonstrated that arginine increased both bulk-solution and localized biofilm pH, partially neutralizing the acidic microenvironment at the biofilm-Ti interface. Overall, these findings suggest that arginine mitigates Ti corrosion primarily through regulating biofilm development and the associated acidic microenvironment, providing new insights into ecological strategies for protection.
Additional Links: PMID-42431100
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@article {pmid42431100,
year = {2026},
author = {Ding, Z and Chen, Z and Wu, J and Jing, Y and Yang, L and Wei, H and Qu, Q and Li, L},
title = {Arginine attenuates microbiologically influenced corrosion of Ti in Candida albicans-Streptococcus oralis cross-kingdom biofilms through pH buffering and biofilm suppression.},
journal = {Bioelectrochemistry (Amsterdam, Netherlands)},
volume = {172},
number = {},
pages = {109378},
doi = {10.1016/j.bioelechem.2026.109378},
pmid = {42431100},
issn = {1878-562X},
abstract = {This study investigates the effect of arginine on Ti corrosion caused by a Candida albicans (C. albicans) and Streptococcus oralis (S. oralis) cross-border biofilm. Electrochemical analyses, surface morphologies and corrosion products analysis were conducted to evaluate the effects of arginine on biofilm-associated corrosion behavior. The results showed that supplementation with 0.25% arginine significantly reduced microbial colonization and biofilm thickness on Ti surfaces, particularly in the cross-border biofilm system. In situ pH analysis further demonstrated that arginine increased both bulk-solution and localized biofilm pH, partially neutralizing the acidic microenvironment at the biofilm-Ti interface. Overall, these findings suggest that arginine mitigates Ti corrosion primarily through regulating biofilm development and the associated acidic microenvironment, providing new insights into ecological strategies for protection.},
}
RevDate: 2026-07-10
The alternative sigma factor SigH modulates biofilm formation and stress tolerance in a raw milk-derived Staphylococcus aureus.
Journal of dairy science pii:S0022-0302(26)03093-6 [Epub ahead of print].
Staphylococcus aureus is an important raw milk contaminant that can persist in dairy environments through biofilm formation and adaptation to environmental stresses. Although the alternative sigma factor SigH has been described in S. aureus, its role in raw milk-associated strains remains poorly understood. In this study, we investigated the function of SigH in the raw milk-derived S. aureus strain RMSA24 in biofilm formation, stress tolerance and antibiotic susceptibility. Deletion of sigH did not affect bacterial growth under routine culture conditions but significantly reduced biofilm formation. In contrast, the sigH mutant exhibited enhanced tolerance to osmotic, acid, and heat stresses. Loss of sigH also reduced susceptibility to the glycopeptide antibiotics vancomycin and teicoplanin and was accompanied by pronounced cell wall thickening. Transcriptomic analysis further supported these phenotypes by revealing differential expression of genes associated with biofilm formation, stress tolerance, and cell wall homeostasis. Overall, these findings indicate that SigH contributes to the regulation of persistence-associated phenotypes in a raw milk-derived S. aureus strain and provide new insights into the regulatory mechanisms that may influence survival of this pathogen in dairy-related environments.
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@article {pmid42431452,
year = {2026},
author = {Li, C and Kong, F and Li, W and Li, B and Xue, T},
title = {The alternative sigma factor SigH modulates biofilm formation and stress tolerance in a raw milk-derived Staphylococcus aureus.},
journal = {Journal of dairy science},
volume = {},
number = {},
pages = {},
doi = {10.3168/jds.2026-28839},
pmid = {42431452},
issn = {1525-3198},
abstract = {Staphylococcus aureus is an important raw milk contaminant that can persist in dairy environments through biofilm formation and adaptation to environmental stresses. Although the alternative sigma factor SigH has been described in S. aureus, its role in raw milk-associated strains remains poorly understood. In this study, we investigated the function of SigH in the raw milk-derived S. aureus strain RMSA24 in biofilm formation, stress tolerance and antibiotic susceptibility. Deletion of sigH did not affect bacterial growth under routine culture conditions but significantly reduced biofilm formation. In contrast, the sigH mutant exhibited enhanced tolerance to osmotic, acid, and heat stresses. Loss of sigH also reduced susceptibility to the glycopeptide antibiotics vancomycin and teicoplanin and was accompanied by pronounced cell wall thickening. Transcriptomic analysis further supported these phenotypes by revealing differential expression of genes associated with biofilm formation, stress tolerance, and cell wall homeostasis. Overall, these findings indicate that SigH contributes to the regulation of persistence-associated phenotypes in a raw milk-derived S. aureus strain and provide new insights into the regulatory mechanisms that may influence survival of this pathogen in dairy-related environments.},
}
RevDate: 2026-07-10
The cyclic adenosine monophosphate-ArcRsa signaling axis modulates biofilm formation in dairy-derived Staphylococcus aureus via transcriptional repression of ica operon.
Journal of dairy science pii:S0022-0302(26)03094-8 [Epub ahead of print].
Staphylococcus aureus has significantly contributed to the contamination of dairy products and preserved foods, attributed to its ability to colonize a wide range of environments and form biofilms. ArcR, the Crp/Fnr family regulatory protein in S. aureus plays key roles in various biological processes. However, the molecular mechanism underlying biofilm regulation by the cAMP-ArcRsa complex remains poorly defined. In this work, we investigated the biological function of ArcRsa in mediating biofilm formation in dairy-derived S. aureus RMSA49. The results demonstrated that the deletion of arcRsa resulted in a dramatic increase in biofilm formation. An in-depth dissection of the regulatory mechanism of ArcRsa revealed that it negatively regulates the production of the polysaccharide intercellular adhesin (PIA) by directly binding to the promoter of the gene icaA. Further analysis revealed that cAMP-ArcRsa complex support biofilm maintenance of S. aureus RMSA 49 by strengthening its regulation of genes icaA. ArcRsa controls the transcription of its own gene and icaA by attaching to specific sequences at the site arcRsa (5'-ATCACGCGACAA-3') and site arcRsa2 (5'-ATTAAGTTGCAA-3'). Our results demonstrate functional crosstalk between cAMP and ArcRsa through direct regulation at the gene icaA promoter, supporting an essential regulatory role for the cAMP-ArcRsa signaling module in modulating biofilm formation in S. aureus.
Additional Links: PMID-42431453
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@article {pmid42431453,
year = {2026},
author = {He, H and Kong, F and Xuan, X and Shang, F and Xue, T},
title = {The cyclic adenosine monophosphate-ArcRsa signaling axis modulates biofilm formation in dairy-derived Staphylococcus aureus via transcriptional repression of ica operon.},
journal = {Journal of dairy science},
volume = {},
number = {},
pages = {},
doi = {10.3168/jds.2026-28916},
pmid = {42431453},
issn = {1525-3198},
abstract = {Staphylococcus aureus has significantly contributed to the contamination of dairy products and preserved foods, attributed to its ability to colonize a wide range of environments and form biofilms. ArcR, the Crp/Fnr family regulatory protein in S. aureus plays key roles in various biological processes. However, the molecular mechanism underlying biofilm regulation by the cAMP-ArcRsa complex remains poorly defined. In this work, we investigated the biological function of ArcRsa in mediating biofilm formation in dairy-derived S. aureus RMSA49. The results demonstrated that the deletion of arcRsa resulted in a dramatic increase in biofilm formation. An in-depth dissection of the regulatory mechanism of ArcRsa revealed that it negatively regulates the production of the polysaccharide intercellular adhesin (PIA) by directly binding to the promoter of the gene icaA. Further analysis revealed that cAMP-ArcRsa complex support biofilm maintenance of S. aureus RMSA 49 by strengthening its regulation of genes icaA. ArcRsa controls the transcription of its own gene and icaA by attaching to specific sequences at the site arcRsa (5'-ATCACGCGACAA-3') and site arcRsa2 (5'-ATTAAGTTGCAA-3'). Our results demonstrate functional crosstalk between cAMP and ArcRsa through direct regulation at the gene icaA promoter, supporting an essential regulatory role for the cAMP-ArcRsa signaling module in modulating biofilm formation in S. aureus.},
}
RevDate: 2026-07-10
Polymicrobial infection requires higher concentration of irrigation solution than monomicrobial infection to eradicate biofilm grown on titanium surface: an in-vitro analysis.
The Journal of hospital infection pii:S0195-6701(26)00269-0 [Epub ahead of print].
BACKGROUND: Polymicrobial periprosthetic joint infection (PJI) is associated with poor outcomes after debridement, antibiotics, and implant retention (DAIR). Although irrigation is a critical component of DAIR, the concentrations required to eradicate polymicrobial biofilms remain unclear.
AIM: To evaluate the in-vitro efficacy of four antiseptic irrigation solutions against mono- and polymicrobial biofilms formed on clinically relevant titanium implant surfaces.
METHODS: Biofilms of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans were grown on Ti-6Al-4V screw-hole covers. Povidone iodine (PI), acetic acid (AA), Granudacyn®, and chlorhexidine were tested. Minimal inhibitory, bactericidal, and biofilm eradication concentrations (MIC, MBC, MBEC) were determined. A 3-minute irrigation assay assessed concentrations achieving ≥99.9% biofilm reduction in mono- and polymicrobial models.
FINDINGS: PI demonstrated the greatest relative effectiveness in eradicating both monomicrobial and polymicrobial biofilms among the tested irrigation solutions. AA and chlorhexidine required substantially higher concentrations than their respective MBEC to achieve 99.9% biofilm eradication, whereas Granudacyn showed limited activity and failed to achieve complete eradication in either condition. Higher irrigation solution concentrations were consistently required to eradicate polymicrobial biofilms compared with monomicrobial biofilms across all agents. In particular, PI and AA required two- to fourfold higher concentrations, and chlorhexidine required approximately 10-fold higher concentrations, for polymicrobial biofilm eradication.
CONCLUSIONS: Polymicrobial biofilms demonstrate significantly increased tolerance to antiseptic irrigation compared with monomicrobial biofilms. Irrigation strategies effective against single-species infections may be inadequate in polymicrobial PJI, supporting the need for higher-concentration or optimized antiseptic protocols during DAIR.
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@article {pmid42431552,
year = {2026},
author = {Semeshchenko, D and Farinati, A and Huespe, I and Albani-Forneris, AF and Buttaro, MA and Slullitel, PA and Meller, S and , },
title = {Polymicrobial infection requires higher concentration of irrigation solution than monomicrobial infection to eradicate biofilm grown on titanium surface: an in-vitro analysis.},
journal = {The Journal of hospital infection},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jhin.2026.06.026},
pmid = {42431552},
issn = {1532-2939},
abstract = {BACKGROUND: Polymicrobial periprosthetic joint infection (PJI) is associated with poor outcomes after debridement, antibiotics, and implant retention (DAIR). Although irrigation is a critical component of DAIR, the concentrations required to eradicate polymicrobial biofilms remain unclear.
AIM: To evaluate the in-vitro efficacy of four antiseptic irrigation solutions against mono- and polymicrobial biofilms formed on clinically relevant titanium implant surfaces.
METHODS: Biofilms of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans were grown on Ti-6Al-4V screw-hole covers. Povidone iodine (PI), acetic acid (AA), Granudacyn®, and chlorhexidine were tested. Minimal inhibitory, bactericidal, and biofilm eradication concentrations (MIC, MBC, MBEC) were determined. A 3-minute irrigation assay assessed concentrations achieving ≥99.9% biofilm reduction in mono- and polymicrobial models.
FINDINGS: PI demonstrated the greatest relative effectiveness in eradicating both monomicrobial and polymicrobial biofilms among the tested irrigation solutions. AA and chlorhexidine required substantially higher concentrations than their respective MBEC to achieve 99.9% biofilm eradication, whereas Granudacyn showed limited activity and failed to achieve complete eradication in either condition. Higher irrigation solution concentrations were consistently required to eradicate polymicrobial biofilms compared with monomicrobial biofilms across all agents. In particular, PI and AA required two- to fourfold higher concentrations, and chlorhexidine required approximately 10-fold higher concentrations, for polymicrobial biofilm eradication.
CONCLUSIONS: Polymicrobial biofilms demonstrate significantly increased tolerance to antiseptic irrigation compared with monomicrobial biofilms. Irrigation strategies effective against single-species infections may be inadequate in polymicrobial PJI, supporting the need for higher-concentration or optimized antiseptic protocols during DAIR.},
}
RevDate: 2026-07-10
Surface characteristics and initial supragingival biofilm formation on additively manufactured zirconia and resin: An in situ study.
Journal of dentistry pii:S0300-5712(26)00564-6 [Epub ahead of print].
OBJECTIVES: This in situ study investigated initial supragingival microbial adhesion and biofilm formation on additively manufactured zirconia (AM-ZrO2) and additively manufactured composite resin (AM-RMC) surfaces, using subtractively manufactured zirconia (SM-ZrO2) as a control material.
MATERIALS AND METHODS: AM-ZrO₂ and AM-RMC specimens were fabricated, with subtractively manufactured zirconia (SM-ZrO₂) as a control. Surface characteristics were analyzed using scanning electron microscopy (SEM), profilometric measurements, and water contact angle assessment. Protein adsorption was evaluated in vitro. As for the in situ study, customized intraoral splints were made and worn by 12 volunteers, and the microbial adhesion was assessed. The adherent bacteria were then examined by live/dead staining for viability and SEM for topography.
RESULTS: Different material compositions and manufacturing technologies lead to distinct surface topographies observed across SM-ZrO2, AM-ZrO2, and AM-RMC. AM-ZrO2 possessed the lowest Sa value (0.53 ± 0.08 μm, p < 0.05), whereas SM-ZrO2 revealed the highest wettability (water contact angle = 92.18 ± 4.96°, p < 0.05). In protein adsorption, AM-RMC showed the highest adsorption capacity (0.64 ± 0.04 μg/cm², p < 0.05). AM-ZrO2 demonstrated the highest level of microbial adhesion, which was significantly greater than that on SM-ZrO2 and AM-RMC (p < 0.05).
CONCLUSIONS: Material type and manufacturing technologies significantly affected surface characteristics and early biofilm formation. Specifically, bacterial adhesion was at its highest level on AM-ZrO₂, surpassing that observed on both AM-RMC and SM-ZrO₂.
CLINICAL SIGNIFICANCE: AM-RMC demonstrated acceptable antibiofilm performance, positioning it as a potential material for personalized restorations. Furthermore, AM-ZrO2 required post-processing and surface modification to reduce bacterial adhesion.
Additional Links: PMID-42431584
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PubMed:
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@article {pmid42431584,
year = {2026},
author = {Lu, J and Wu, K and He, Y and Xu, Z and Zhu, P and Wang, F and Li, P},
title = {Surface characteristics and initial supragingival biofilm formation on additively manufactured zirconia and resin: An in situ study.},
journal = {Journal of dentistry},
volume = {},
number = {},
pages = {106894},
doi = {10.1016/j.jdent.2026.106894},
pmid = {42431584},
issn = {1879-176X},
abstract = {OBJECTIVES: This in situ study investigated initial supragingival microbial adhesion and biofilm formation on additively manufactured zirconia (AM-ZrO2) and additively manufactured composite resin (AM-RMC) surfaces, using subtractively manufactured zirconia (SM-ZrO2) as a control material.
MATERIALS AND METHODS: AM-ZrO₂ and AM-RMC specimens were fabricated, with subtractively manufactured zirconia (SM-ZrO₂) as a control. Surface characteristics were analyzed using scanning electron microscopy (SEM), profilometric measurements, and water contact angle assessment. Protein adsorption was evaluated in vitro. As for the in situ study, customized intraoral splints were made and worn by 12 volunteers, and the microbial adhesion was assessed. The adherent bacteria were then examined by live/dead staining for viability and SEM for topography.
RESULTS: Different material compositions and manufacturing technologies lead to distinct surface topographies observed across SM-ZrO2, AM-ZrO2, and AM-RMC. AM-ZrO2 possessed the lowest Sa value (0.53 ± 0.08 μm, p < 0.05), whereas SM-ZrO2 revealed the highest wettability (water contact angle = 92.18 ± 4.96°, p < 0.05). In protein adsorption, AM-RMC showed the highest adsorption capacity (0.64 ± 0.04 μg/cm², p < 0.05). AM-ZrO2 demonstrated the highest level of microbial adhesion, which was significantly greater than that on SM-ZrO2 and AM-RMC (p < 0.05).
CONCLUSIONS: Material type and manufacturing technologies significantly affected surface characteristics and early biofilm formation. Specifically, bacterial adhesion was at its highest level on AM-ZrO₂, surpassing that observed on both AM-RMC and SM-ZrO₂.
CLINICAL SIGNIFICANCE: AM-RMC demonstrated acceptable antibiofilm performance, positioning it as a potential material for personalized restorations. Furthermore, AM-ZrO2 required post-processing and surface modification to reduce bacterial adhesion.},
}
RevDate: 2026-07-10
CmpDate: 2026-07-11
Exploratory analysis of biofilm formation and virulence gene expression in Acinetobacter baumannii-Candida albicans co-cultured isolates from urinary tract infections.
Scientific reports, 16(1):.
Polymicrobial infections with Acinetobacter baumannii (A. baumannii) and Candida albicans (C. albicans) are increasingly frequent in urinary tract infections (UTIs). However, experimental data describing their interactions in clinical isolates under co-culture conditions remain limited. In this study, three clinical isolates of both A. baumannii and C. albicans were co-isolated from urine samples with UTIs, then mono-cultured and co-cultured at 24, 48, and 72 h for biofilm quantification by crystal violet assay. The expression levels of bacterial (ompA, bap, abaI) and fungal (ALS3, HWP1, ERG11) virulence genes were evaluated by RT-qPCR at 24 and 48 h. Co-culture conditions resulted in increased biofilm biomass compared to monoculture for the tested isolates. In A. baumannii, the virulence genes of bap, abaI, and ompA showed statistically significant increase in expression in co-culture compared to mono-culture after 24 h. In C. albicans, HWP1 is the only virulence gene that shows a statistically significant increase in expression in co-culture compared to monoculture after 48 h. Gene expression patterns varied in patient isolates, suggesting strain heterogeneity. This is an exploratory study that provides evidence of changes in biofilm formation and virulence gene expression in co-culture conditions among clinical isolates of A. baumannii and C. albicans. These findings suggest potential for microbial interactions under polymicrobial conditions, which might affect the diagnosis and treatment of patients with UTIs. Future studies with a larger number of isolates and functional assays are required to clarify the mechanistic regulation and biological relevance of these observations in UTIs.
Additional Links: PMID-42431945
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Citation:
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@article {pmid42431945,
year = {2026},
author = {Hossam, B and Gabre, RM and Amr, D and Saleh, HH},
title = {Exploratory analysis of biofilm formation and virulence gene expression in Acinetobacter baumannii-Candida albicans co-cultured isolates from urinary tract infections.},
journal = {Scientific reports},
volume = {16},
number = {1},
pages = {},
pmid = {42431945},
issn = {2045-2322},
mesh = {*Biofilms/growth & development ; *Candida albicans/genetics/isolation & purification/pathogenicity/physiology ; Humans ; *Acinetobacter baumannii/genetics/isolation & purification/physiology/pathogenicity ; Coculture Techniques ; *Urinary Tract Infections/microbiology ; Virulence/genetics ; *Virulence Factors/genetics ; Gene Expression Regulation, Fungal ; Coinfection/microbiology ; },
abstract = {Polymicrobial infections with Acinetobacter baumannii (A. baumannii) and Candida albicans (C. albicans) are increasingly frequent in urinary tract infections (UTIs). However, experimental data describing their interactions in clinical isolates under co-culture conditions remain limited. In this study, three clinical isolates of both A. baumannii and C. albicans were co-isolated from urine samples with UTIs, then mono-cultured and co-cultured at 24, 48, and 72 h for biofilm quantification by crystal violet assay. The expression levels of bacterial (ompA, bap, abaI) and fungal (ALS3, HWP1, ERG11) virulence genes were evaluated by RT-qPCR at 24 and 48 h. Co-culture conditions resulted in increased biofilm biomass compared to monoculture for the tested isolates. In A. baumannii, the virulence genes of bap, abaI, and ompA showed statistically significant increase in expression in co-culture compared to mono-culture after 24 h. In C. albicans, HWP1 is the only virulence gene that shows a statistically significant increase in expression in co-culture compared to monoculture after 48 h. Gene expression patterns varied in patient isolates, suggesting strain heterogeneity. This is an exploratory study that provides evidence of changes in biofilm formation and virulence gene expression in co-culture conditions among clinical isolates of A. baumannii and C. albicans. These findings suggest potential for microbial interactions under polymicrobial conditions, which might affect the diagnosis and treatment of patients with UTIs. Future studies with a larger number of isolates and functional assays are required to clarify the mechanistic regulation and biological relevance of these observations in UTIs.},
}
MeSH Terms:
show MeSH Terms
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*Biofilms/growth & development
*Candida albicans/genetics/isolation & purification/pathogenicity/physiology
Humans
*Acinetobacter baumannii/genetics/isolation & purification/physiology/pathogenicity
Coculture Techniques
*Urinary Tract Infections/microbiology
Virulence/genetics
*Virulence Factors/genetics
Gene Expression Regulation, Fungal
Coinfection/microbiology
RevDate: 2026-07-10
CmpDate: 2026-07-11
Data-driven exploration of electronic nose technology to differentiate bacteria in blood cultures under biofilm-promoting conditions.
Scientific reports, 16(1):.
Biofilms are a major cause of delayed wound healing, yet current biofilm identification methods are limited by invasiveness, processing times, or specificity. This study investigates the potential of metal-oxide electronic noses for identifying bacterial cultures of Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecium, and Staphylococcus epidermidis grown in blood-based growth medium. We conducted in-vitro experiments to capture volatilome signatures from cultures grown under biofilm-promoting conditions and analyzed data using an interpretable machine learning workflow to disentangle algorithmic limitations from biological variability. This workflow incorporated feature extraction and selection, correlation-based clustering, and Shapley analysis. Six classification models were evaluated using cross-validation. Considering all five classes, classification accuracy reached at most 55.6%, which Shapley-based interpretation attributed mainly to biological factors: E. faecium and S. aureus exhibited high signal similarity to control samples and strong inter-day variability. Accuracy increased to 100.0% for species with distinct volatile signatures, and dimensionality reduction resulted in a model using two constructed features. These findings demonstrate that classification performance in biological sensing cannot be explained solely by algorithmic factors. Interpretable machine learning workflows help for distinguishing biological sources of complexity from algorithmic ones. We provide a proof-of-principle for electronic nose-based identification of bacterial growth under biofilm-promoting conditions.
Additional Links: PMID-42432108
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Citation:
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@article {pmid42432108,
year = {2026},
author = {Wörner, J and van Leuven, N and Eimler, J and Odefey, U and Bockmühl, DP and Pein-Hackelbusch, M},
title = {Data-driven exploration of electronic nose technology to differentiate bacteria in blood cultures under biofilm-promoting conditions.},
journal = {Scientific reports},
volume = {16},
number = {1},
pages = {},
pmid = {42432108},
issn = {2045-2322},
mesh = {*Biofilms/growth & development ; *Electronic Nose ; *Blood Culture/methods ; Staphylococcus aureus/isolation & purification ; Humans ; *Bacteria/isolation & purification/classification/growth & development ; Machine Learning ; Classification Algorithms ; Pseudomonas aeruginosa/isolation & purification ; Staphylococcus epidermidis/isolation & purification ; },
abstract = {Biofilms are a major cause of delayed wound healing, yet current biofilm identification methods are limited by invasiveness, processing times, or specificity. This study investigates the potential of metal-oxide electronic noses for identifying bacterial cultures of Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecium, and Staphylococcus epidermidis grown in blood-based growth medium. We conducted in-vitro experiments to capture volatilome signatures from cultures grown under biofilm-promoting conditions and analyzed data using an interpretable machine learning workflow to disentangle algorithmic limitations from biological variability. This workflow incorporated feature extraction and selection, correlation-based clustering, and Shapley analysis. Six classification models were evaluated using cross-validation. Considering all five classes, classification accuracy reached at most 55.6%, which Shapley-based interpretation attributed mainly to biological factors: E. faecium and S. aureus exhibited high signal similarity to control samples and strong inter-day variability. Accuracy increased to 100.0% for species with distinct volatile signatures, and dimensionality reduction resulted in a model using two constructed features. These findings demonstrate that classification performance in biological sensing cannot be explained solely by algorithmic factors. Interpretable machine learning workflows help for distinguishing biological sources of complexity from algorithmic ones. We provide a proof-of-principle for electronic nose-based identification of bacterial growth under biofilm-promoting conditions.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Electronic Nose
*Blood Culture/methods
Staphylococcus aureus/isolation & purification
Humans
*Bacteria/isolation & purification/classification/growth & development
Machine Learning
Classification Algorithms
Pseudomonas aeruginosa/isolation & purification
Staphylococcus epidermidis/isolation & purification
RevDate: 2026-07-10
Gramicidin D as a Multi-Target Antimicrobial Against Staphylococcus aureus: Biofilm Disruption, Virulence Attenuation, Antibiotic Potentiation, and Protein-Peptide Docking Insight.
Probiotics and antimicrobial proteins [Epub ahead of print].
Over the past decades, the threat of Staphylococcus aureus and multidrug-resistant S. aureus has escalated, creating an urgent need for novel therapeutic strategies that possess both bactericidal and antivirulence properties. We focused on gramicidin D, a conventional pore-forming antibiotic derived from Bacillus brevis, as a multi-target agent. The minimum inhibitory concentration (MIC) and half-maximal inhibitory concentration (IC50) against several Gram-positive pathogens were determined by broth microdilution assay. Furthermore, the combinatorial effect with other conventional antibiotics was also assayed via the checkerboard method. The effects on biofilm formation and mature biofilm were evaluated using the crystal violet staining method, supported by colony-forming unit (CFU) counts. Additionally, inhibition of staphyloxanthin biosynthesis was quantified by methanol extraction, followed by measurement of optical density via a microplate reader. Finally, in silico protein-peptide docking was performed to support and analyze the properties of the peptide. Gramicidin D demonstrated significant antibacterial efficacy against S. aureus and methicillin-resistant S. aureus (MRSA), with corresponding MIC values of 8 and 0.25 µg/mL, respectively. Moreover, gramicidin exhibited synergistic effects with oxacillin and gentamicin against S. aureus; however, it showed synergy with oxacillin only against MRSA. It inhibited S. aureus biofilm formation at sub-MICs, especially at 0.125 µg/mL, where 80.0% of biofilm was inhibited. Furthermore, it effectively reduced established biofilm at concentrations ranging from 128 to 4 µg/mL. Additional SEM images showed that membrane pore formation by gramicidin D was supported. It also inhibited staphyloxanthin synthesis at all concentrations ≥ 1 µg/mL. HDOCK server-based protein-peptide docking provided structural support for the in vitro experiments. These findings altogether illustrated the potential of gramicidin D as a multi-target agent against S. aureus.
Additional Links: PMID-42432311
PubMed:
Citation:
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@article {pmid42432311,
year = {2026},
author = {Kim, T and Tabassum, N and Javaid, A and Khan, F},
title = {Gramicidin D as a Multi-Target Antimicrobial Against Staphylococcus aureus: Biofilm Disruption, Virulence Attenuation, Antibiotic Potentiation, and Protein-Peptide Docking Insight.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {42432311},
issn = {1867-1314},
support = {RS-2023-00241461//Basic Science Research Program through the National Research Foundation (NRF) of Korea grant funded by the Ministry of Education/ ; },
abstract = {Over the past decades, the threat of Staphylococcus aureus and multidrug-resistant S. aureus has escalated, creating an urgent need for novel therapeutic strategies that possess both bactericidal and antivirulence properties. We focused on gramicidin D, a conventional pore-forming antibiotic derived from Bacillus brevis, as a multi-target agent. The minimum inhibitory concentration (MIC) and half-maximal inhibitory concentration (IC50) against several Gram-positive pathogens were determined by broth microdilution assay. Furthermore, the combinatorial effect with other conventional antibiotics was also assayed via the checkerboard method. The effects on biofilm formation and mature biofilm were evaluated using the crystal violet staining method, supported by colony-forming unit (CFU) counts. Additionally, inhibition of staphyloxanthin biosynthesis was quantified by methanol extraction, followed by measurement of optical density via a microplate reader. Finally, in silico protein-peptide docking was performed to support and analyze the properties of the peptide. Gramicidin D demonstrated significant antibacterial efficacy against S. aureus and methicillin-resistant S. aureus (MRSA), with corresponding MIC values of 8 and 0.25 µg/mL, respectively. Moreover, gramicidin exhibited synergistic effects with oxacillin and gentamicin against S. aureus; however, it showed synergy with oxacillin only against MRSA. It inhibited S. aureus biofilm formation at sub-MICs, especially at 0.125 µg/mL, where 80.0% of biofilm was inhibited. Furthermore, it effectively reduced established biofilm at concentrations ranging from 128 to 4 µg/mL. Additional SEM images showed that membrane pore formation by gramicidin D was supported. It also inhibited staphyloxanthin synthesis at all concentrations ≥ 1 µg/mL. HDOCK server-based protein-peptide docking provided structural support for the in vitro experiments. These findings altogether illustrated the potential of gramicidin D as a multi-target agent against S. aureus.},
}
RevDate: 2026-07-08
Nanomedicine strategies against multidrug-resistant Acinetobacter baumannii: Delivery, biofilm disruption, and translational considerations.
Nanomedicine : nanotechnology, biology, and medicine pii:S1549-9634(26)00094-8 [Epub ahead of print].
Acinetobacter baumannii has become a high-priority global problem because it causes hospital-acquired infections and ventilator-associated pneumonia, and multidrug resistance, environmental survivability, and biofilm formation severely restrict therapeutic choices. Antimicrobial nanomedicine has become a major focus as a translational approach. This review critically explores nanotechnology-based interventions for A. baumannii. Multimodal antibacterial and antibiofilm activities have been demonstrated in inorganic nanoparticles, such as silver, gold, and copper-based systems, with an emphasis on their translational therapeutic potential and nano-bio interactions. Polymer- and lipid-based nanocarriers focus on optimising pharmacokinetics, controlled release, and targeted delivery, supporting improved bioavailability and site-specific exposure. Carbon nanomaterials offer alternative antibacterial mechanisms but raise concerns regarding biodegradability and safety. Overall, antimicrobial nanomedicine can be considered an exposure- and delivery-focused system with significant potential for treating persistent drug-resistant A. baumannii infections, highlighting the translational, toxicological, and regulatory challenges relevant to clinical adoption.
Additional Links: PMID-42419610
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PubMed:
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@article {pmid42419610,
year = {2026},
author = {Khan, A and Alzahrani, HA and Alenezi, T and Ali, YH and Saeed, IK and Rehman, ZU and Shakeel, F and Imran, M},
title = {Nanomedicine strategies against multidrug-resistant Acinetobacter baumannii: Delivery, biofilm disruption, and translational considerations.},
journal = {Nanomedicine : nanotechnology, biology, and medicine},
volume = {},
number = {},
pages = {102993},
doi = {10.1016/j.nano.2026.102993},
pmid = {42419610},
issn = {1549-9642},
abstract = {Acinetobacter baumannii has become a high-priority global problem because it causes hospital-acquired infections and ventilator-associated pneumonia, and multidrug resistance, environmental survivability, and biofilm formation severely restrict therapeutic choices. Antimicrobial nanomedicine has become a major focus as a translational approach. This review critically explores nanotechnology-based interventions for A. baumannii. Multimodal antibacterial and antibiofilm activities have been demonstrated in inorganic nanoparticles, such as silver, gold, and copper-based systems, with an emphasis on their translational therapeutic potential and nano-bio interactions. Polymer- and lipid-based nanocarriers focus on optimising pharmacokinetics, controlled release, and targeted delivery, supporting improved bioavailability and site-specific exposure. Carbon nanomaterials offer alternative antibacterial mechanisms but raise concerns regarding biodegradability and safety. Overall, antimicrobial nanomedicine can be considered an exposure- and delivery-focused system with significant potential for treating persistent drug-resistant A. baumannii infections, highlighting the translational, toxicological, and regulatory challenges relevant to clinical adoption.},
}
RevDate: 2026-07-08
PEEK containing titanium dioxide fillers promotes biofilm formation.
Dental materials : official publication of the Academy of Dental Materials pii:S0109-5641(26)00375-1 [Epub ahead of print].
OBJECTIVES: Polyaryletherketones (PAEKs) are widely used in dentistry due to their high biocompatibility, while their physical and mechanical properties are frequently modified using fillers and additives. Effects of these modifications on biocompatibility and biofilm formation remain unclear. This study investigated the influence of different PAEK compositions on the quantity and composition of biofilms.
METHODS: Five PAEKs (unfilled PEEK, filled PEEK, pressed PEEK, PEKK, and AKP) and reference materials (titanium, zirconium dioxide, PMMA) were polished to Ra values below 0.2 µm to control for topographical effects. Surface morphology and composition were determined by scanning electron microscopy and wavelength-dispersive X-ray spectroscopy on an electron microprobe (WD-EPMA). Surface free energy (SFE) was analyzed by contact angle measurement. Custom-made intraoral splints with mounted material specimens were worn by 20 participants for 24 h. Biofilm formation was analyzed using microscopy and qPCR. Two PEEK types (filled and unfilled) underwent additional 24-hour exposures by six participants and were analyzed for microbial differences. Additionally, filled and unfilled PEEK were compared to titanium in CCK-8 assays using human fibroblasts.
RESULTS: All materials exhibited homogeneous surface morphology. SFE was significantly higher (p < 0.0005) for all materials compared to titanium, except for zirconium dioxide. Filled PEEK showed increased biofilm formation compared with unfilled PEEK in vitro and in vivo (p < 0.0001), while biofilm composition remained unchanged. Only PEEK containing TiO₂ was associated with increased biofilm formation, without improving fibroblast viability.
SIGNIFICANCE: TiO₂ in PEEK increased biofilm formation without enhancing fibroblast viability, indicating that material fillers can affect microbial colonization independently of cellular biocompatibility.
Additional Links: PMID-42420082
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PubMed:
Citation:
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@article {pmid42420082,
year = {2026},
author = {Deerberg, J and Sasse, C and Kronz, A and Lindner, AS and Abbasi, A and Huynh, TAJ and Wassmann, T and Kurbad, O and Bürgers, R and Bunz, O},
title = {PEEK containing titanium dioxide fillers promotes biofilm formation.},
journal = {Dental materials : official publication of the Academy of Dental Materials},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.dental.2026.07.002},
pmid = {42420082},
issn = {1879-0097},
abstract = {OBJECTIVES: Polyaryletherketones (PAEKs) are widely used in dentistry due to their high biocompatibility, while their physical and mechanical properties are frequently modified using fillers and additives. Effects of these modifications on biocompatibility and biofilm formation remain unclear. This study investigated the influence of different PAEK compositions on the quantity and composition of biofilms.
METHODS: Five PAEKs (unfilled PEEK, filled PEEK, pressed PEEK, PEKK, and AKP) and reference materials (titanium, zirconium dioxide, PMMA) were polished to Ra values below 0.2 µm to control for topographical effects. Surface morphology and composition were determined by scanning electron microscopy and wavelength-dispersive X-ray spectroscopy on an electron microprobe (WD-EPMA). Surface free energy (SFE) was analyzed by contact angle measurement. Custom-made intraoral splints with mounted material specimens were worn by 20 participants for 24 h. Biofilm formation was analyzed using microscopy and qPCR. Two PEEK types (filled and unfilled) underwent additional 24-hour exposures by six participants and were analyzed for microbial differences. Additionally, filled and unfilled PEEK were compared to titanium in CCK-8 assays using human fibroblasts.
RESULTS: All materials exhibited homogeneous surface morphology. SFE was significantly higher (p < 0.0005) for all materials compared to titanium, except for zirconium dioxide. Filled PEEK showed increased biofilm formation compared with unfilled PEEK in vitro and in vivo (p < 0.0001), while biofilm composition remained unchanged. Only PEEK containing TiO₂ was associated with increased biofilm formation, without improving fibroblast viability.
SIGNIFICANCE: TiO₂ in PEEK increased biofilm formation without enhancing fibroblast viability, indicating that material fillers can affect microbial colonization independently of cellular biocompatibility.},
}
RevDate: 2026-07-09
CmpDate: 2026-07-09
Biodegradable vs. conventional toothbrushes for biofilm control: a systematic review and meta-analysis of randomized trials.
Frontiers in oral health, 7:1846306.
BACKGROUND: Due to the immense environmental impact of plastic waste, there has been a significant increase in interest for both biodegradable and natural toothbrushes (BT) as sustainable forms of daily oral care. This includes bamboo toothbrushes, as well as plant-based products (i.e., miswak). As such, these two types of products can be considered similar because they are both renewable and biodegradable in nature. However, their effectiveness when compared to traditional plastic toothbrushes at controlling dental biofilm has not been fully established.
OBJECTIVE: To evaluate the effectiveness of biodegradable and natural oral hygiene tools compared with conventional plastic toothbrushes for controlling dental plaque in children and adults.
METHODS: This systematic review/meta-analysis was reported according to PRISMA guidelines, and its protocol was registered in PROSPERO. All databases were searched using electronic methods from their inception to December 2025: PubMed, Scopus, Web of Science, and Embase. All randomized controlled trials (RCTs) that examined biodegradable/natural oral hygiene products compared to conventional plastic toothbrushes and that had plaque index (PI) as outcome were included. The analyses used random effects model, and certainty of evidence was evaluated using GRADE methodology.
RESULTS: Five RCTs (n = 408) met the criteria for inclusion. There was no clear difference in plaque index between biodegradable/natural oral hygiene tools and conventional plastic toothbrushes [mean difference (MD): -0.09, 95% CI: -0.47 to 0.29]. However, the pooled estimate was characterized by very high statistical heterogeneity (I [2] = 89%) and the certainty of the evidence was rated as very low, which substantially limits confidence in this result. The results of subgroup analyses according to type of oral hygiene tool and population did not show any meaningful differences from those of the pooled analysis. The overall certainty of evidence was rated as very low and had a high risk of bias.
CONCLUSIONS: Biodegradable and natural oral hygiene products may result in little to no difference in plaque control compared with conventional plastic toothbrushes; however, confidence in this estimate was very low. Well-designed, adequately powered RCTs are required to reduce uncertainty and inform evidence-based clinical and sustainability-related recommendations.
https://www.crd.york.ac.uk/PROSPERO/view/CRD420251273997, PROSPERO CRD420251273997.
Additional Links: PMID-42421793
PubMed:
Citation:
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@article {pmid42421793,
year = {2026},
author = {Mayta-Tovalino, F and Espinoza-Carhuancho, F and Mauricio-Vilchez, C and Calderon-Cortez, I and Cabanillas-Lazo, M and V Hernandez, A},
title = {Biodegradable vs. conventional toothbrushes for biofilm control: a systematic review and meta-analysis of randomized trials.},
journal = {Frontiers in oral health},
volume = {7},
number = {},
pages = {1846306},
pmid = {42421793},
issn = {2673-4842},
abstract = {BACKGROUND: Due to the immense environmental impact of plastic waste, there has been a significant increase in interest for both biodegradable and natural toothbrushes (BT) as sustainable forms of daily oral care. This includes bamboo toothbrushes, as well as plant-based products (i.e., miswak). As such, these two types of products can be considered similar because they are both renewable and biodegradable in nature. However, their effectiveness when compared to traditional plastic toothbrushes at controlling dental biofilm has not been fully established.
OBJECTIVE: To evaluate the effectiveness of biodegradable and natural oral hygiene tools compared with conventional plastic toothbrushes for controlling dental plaque in children and adults.
METHODS: This systematic review/meta-analysis was reported according to PRISMA guidelines, and its protocol was registered in PROSPERO. All databases were searched using electronic methods from their inception to December 2025: PubMed, Scopus, Web of Science, and Embase. All randomized controlled trials (RCTs) that examined biodegradable/natural oral hygiene products compared to conventional plastic toothbrushes and that had plaque index (PI) as outcome were included. The analyses used random effects model, and certainty of evidence was evaluated using GRADE methodology.
RESULTS: Five RCTs (n = 408) met the criteria for inclusion. There was no clear difference in plaque index between biodegradable/natural oral hygiene tools and conventional plastic toothbrushes [mean difference (MD): -0.09, 95% CI: -0.47 to 0.29]. However, the pooled estimate was characterized by very high statistical heterogeneity (I [2] = 89%) and the certainty of the evidence was rated as very low, which substantially limits confidence in this result. The results of subgroup analyses according to type of oral hygiene tool and population did not show any meaningful differences from those of the pooled analysis. The overall certainty of evidence was rated as very low and had a high risk of bias.
CONCLUSIONS: Biodegradable and natural oral hygiene products may result in little to no difference in plaque control compared with conventional plastic toothbrushes; however, confidence in this estimate was very low. Well-designed, adequately powered RCTs are required to reduce uncertainty and inform evidence-based clinical and sustainability-related recommendations.
https://www.crd.york.ac.uk/PROSPERO/view/CRD420251273997, PROSPERO CRD420251273997.},
}
RevDate: 2026-07-09
CmpDate: 2026-07-10
New insights into the resistome-mobilome-biofilm relationship in Vibrio parahaemolyticus.
Food microbiology, 140:105162.
Vibrio parahaemolyticus is a major foodborne pathogen frequently isolated from seafood, notable for its biofilm-forming capacity, which enhances its persistence in environments and increases resistance to disinfection. This study investigated the virulome, the associations between the resistome and mobilome of V. parahaemolyticus and its biofilm forming ability to better understand the genomic determinants of persistence. Among 845 isolates from imported seafood (mainly shrimp), 20.6% showed acquired resistance to at least one clinically important antibiotic class, most commonly tetracycline, sulfamethoxazole-trimethoprim, and streptomycin. Thirty-nine representative strains (resistant and susceptible) were selected for confocal laser scanning microscopy (CLSM) observation of biofilms and whole-genome sequencing (WGS). CLSM combined with image analysis revealed significant variability in biofilm formation, with no relation with specific phylogenetic lineage. Hybrid WGS (short and long reads) identified 49 distinct antimicrobial resistance genes (ARGs) and 44 highly conserved virulence genes. ARGs were found on both chromosomes and plasmids and were strongly associated with mobile genetic elements (MGEs). dfrA8 and blaCARB-3 and several novel ARG-MGE associations were detected by genomic analysis in V. parahaemolyticus genome, including blaCARB-3-IS6 or dfrA8-IS6. Interestingly, several resistome-mobilome associations, notably dfrA23, blaCTX-M-15-IS6, and floR-IS91, were significantly correlated with variations in biofilm height, roughness, substrate coverage, and volume. Moreover, a particularly strong association was observed for tet(A), whose presence was closely linked to reduced biofilm roughness. However, no association was found between phenotypic antibiotic resistance and biofilm formation metrics, except for a significant link between quinolone resistance and increased biofilm height. These findings provide new insights into the genomic factors underlying biofilm-associated persistence in V. parahaemolyticus.
Additional Links: PMID-42425641
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@article {pmid42425641,
year = {2026},
author = {Régnier, A and Chesnais, V and Dumaire, C and Berdous, C and Briandet, R and Debuiche, S and Guéneau, V and Midelet, G and Gay, M and Brauge, T},
title = {New insights into the resistome-mobilome-biofilm relationship in Vibrio parahaemolyticus.},
journal = {Food microbiology},
volume = {140},
number = {},
pages = {105162},
doi = {10.1016/j.fm.2026.105162},
pmid = {42425641},
issn = {1095-9998},
mesh = {*Biofilms/growth & development/drug effects ; *Vibrio parahaemolyticus/genetics/drug effects/physiology/isolation & purification ; Anti-Bacterial Agents/pharmacology ; *Seafood/microbiology ; Genome, Bacterial ; *Drug Resistance, Bacterial/genetics ; Animals ; Whole Genome Sequencing ; Phylogeny ; Virulence Factors/genetics ; Microbial Sensitivity Tests ; Bacterial Proteins/genetics/metabolism ; },
abstract = {Vibrio parahaemolyticus is a major foodborne pathogen frequently isolated from seafood, notable for its biofilm-forming capacity, which enhances its persistence in environments and increases resistance to disinfection. This study investigated the virulome, the associations between the resistome and mobilome of V. parahaemolyticus and its biofilm forming ability to better understand the genomic determinants of persistence. Among 845 isolates from imported seafood (mainly shrimp), 20.6% showed acquired resistance to at least one clinically important antibiotic class, most commonly tetracycline, sulfamethoxazole-trimethoprim, and streptomycin. Thirty-nine representative strains (resistant and susceptible) were selected for confocal laser scanning microscopy (CLSM) observation of biofilms and whole-genome sequencing (WGS). CLSM combined with image analysis revealed significant variability in biofilm formation, with no relation with specific phylogenetic lineage. Hybrid WGS (short and long reads) identified 49 distinct antimicrobial resistance genes (ARGs) and 44 highly conserved virulence genes. ARGs were found on both chromosomes and plasmids and were strongly associated with mobile genetic elements (MGEs). dfrA8 and blaCARB-3 and several novel ARG-MGE associations were detected by genomic analysis in V. parahaemolyticus genome, including blaCARB-3-IS6 or dfrA8-IS6. Interestingly, several resistome-mobilome associations, notably dfrA23, blaCTX-M-15-IS6, and floR-IS91, were significantly correlated with variations in biofilm height, roughness, substrate coverage, and volume. Moreover, a particularly strong association was observed for tet(A), whose presence was closely linked to reduced biofilm roughness. However, no association was found between phenotypic antibiotic resistance and biofilm formation metrics, except for a significant link between quinolone resistance and increased biofilm height. These findings provide new insights into the genomic factors underlying biofilm-associated persistence in V. parahaemolyticus.},
}
MeSH Terms:
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*Biofilms/growth & development/drug effects
*Vibrio parahaemolyticus/genetics/drug effects/physiology/isolation & purification
Anti-Bacterial Agents/pharmacology
*Seafood/microbiology
Genome, Bacterial
*Drug Resistance, Bacterial/genetics
Animals
Whole Genome Sequencing
Phylogeny
Virulence Factors/genetics
Microbial Sensitivity Tests
Bacterial Proteins/genetics/metabolism
RevDate: 2026-07-08
Biofilm-Binding Phages Enhance Biofilm Eradication by Synergistic Photothermal and Photodynamic Therapy.
Advanced science (Weinheim, Baden-Wurttemberg, Germany) [Epub ahead of print].
Biofilms, a major cause of chronic bacterial infections, present significant treatment challenges due to their protective extracellular matrix that shields bacteria from both antibiotics and host immune defenses. To treat biofilms more effectively, here we discovered a biofilm-binding peptide from a phage library and verified that it selectively bound the polysaccharides on the biofilm. We then engineered M13 phage into trifunctional nanofibers displaying the biofilm-binding peptide at the tip and carrying gold nanoparticles (AuNPs, as photothermal agents) and tetrakis(4-carboxyphenyl) porphyrin (TCPP, as a photosensitizer) on the sidewall for combined phototherapy. This design enhances binding/anchoring and eradication of biofilms by leveraging the unique properties of each component. The phage nanofibers efficiently bound biofilms and promoted the transfer of heat and penetration of reactive oxygen species (ROS) into the biofilm, leading to cell death. Therefore, under light irradiation, the engineered phage nanofibers effectively eradicated the biofilms by AuNP-induced photothermal therapy (PTT) and TCPP-assisted photodynamic therapy (PDT) in a biofilm-associated skin wound model. Transcriptomic profiling suggests stress-response signatures consistent with oxidative/thermal injury. This study presents a promising ternary synergistic strategy for eradicating biofilms, potentially improving clinical outcomes in wound infection management.
Additional Links: PMID-42418439
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@article {pmid42418439,
year = {2026},
author = {Cao, Y and Yang, T and Wang, R and Li, HD and Zhang, XY and Cheng, F and Liu, Y and Wang, JH and Yang, T and Mao, C},
title = {Biofilm-Binding Phages Enhance Biofilm Eradication by Synergistic Photothermal and Photodynamic Therapy.},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
volume = {},
number = {},
pages = {e23904},
doi = {10.1002/advs.202523904},
pmid = {42418439},
issn = {2198-3844},
support = {22174011//National Natural Science Foundation of China/ ; 22374014//National Natural Science Foundation of China/ ; 22074011//National Natural Science Foundation of China/ ; N2405006//Fundamental Research Funds for the Central Universities/ ; N25QNR010//Fundamental Research Funds for the Central Universities/ ; 2024JH3/10200011//Natural Science Foundation of Liaoning Province/ ; 2025YFC3408405//National Key Research and Development Program of China/ ; CRF C4075-24G//Research Grants Council (RGC) of Hong Kong/ ; GRF 14208723//Research Grants Council (RGC) of Hong Kong/ ; GRF 14210225//Research Grants Council (RGC) of Hong Kong/ ; CRS_CUHK401/25//Research Grants Council (RGC) of Hong Kong/ ; },
abstract = {Biofilms, a major cause of chronic bacterial infections, present significant treatment challenges due to their protective extracellular matrix that shields bacteria from both antibiotics and host immune defenses. To treat biofilms more effectively, here we discovered a biofilm-binding peptide from a phage library and verified that it selectively bound the polysaccharides on the biofilm. We then engineered M13 phage into trifunctional nanofibers displaying the biofilm-binding peptide at the tip and carrying gold nanoparticles (AuNPs, as photothermal agents) and tetrakis(4-carboxyphenyl) porphyrin (TCPP, as a photosensitizer) on the sidewall for combined phototherapy. This design enhances binding/anchoring and eradication of biofilms by leveraging the unique properties of each component. The phage nanofibers efficiently bound biofilms and promoted the transfer of heat and penetration of reactive oxygen species (ROS) into the biofilm, leading to cell death. Therefore, under light irradiation, the engineered phage nanofibers effectively eradicated the biofilms by AuNP-induced photothermal therapy (PTT) and TCPP-assisted photodynamic therapy (PDT) in a biofilm-associated skin wound model. Transcriptomic profiling suggests stress-response signatures consistent with oxidative/thermal injury. This study presents a promising ternary synergistic strategy for eradicating biofilms, potentially improving clinical outcomes in wound infection management.},
}
RevDate: 2026-07-08
Transcriptomics and functional analysis reveal impaired motility, biofilm formation, invasion and intramacrophage survival of pimt gene-deleted strain of Salmonella Typhimurium.
International journal of biological macromolecules pii:S0141-8130(26)03318-0 [Epub ahead of print].
Inside the host, Salmonella suffers but survives various stresses. Proteins are the prime targets of host inflammatory responses. Salmonella encodes two key protein repair enzymes, methionine sulfoxide reductase (Msr) and protein isoaspartate methyltransferase (PIMT), that reactivates damaged proteins without their translational synthesis. Under stress, the accumulation of L-isoaspartate (isoAsp) residues causes defects in protein shape and function, which lead to impaired bacterial survival. The PIMT converts the isoAsp residues into Asp residues. Earlier, we observed hypersensitivity of Δpimt mutant strain to various stresses and defective colonisation in mice and poultry. Here, we show that Δpimt mutant strain accumulates about 1.67-fold more intracellular ROS levels and higher protein aggregations. RNA-seq analysis of the pimt gene-deleted strain of S. typhimurium revealed differential expression of 2676 genes. Most of the downregulated genes are related to flagellar assembly, chemotaxis, fimbria formation, Salmonella pathogenicity island encoding type-3 secretion system, mainly implicated in motility, adhesion, invasion and intracellular survival inside intestinal epithelium, phagocytic cells, etc. These factors are known to be the major contributors for the virulence of S. typhimurium inside the host. The functional analysis revealed that the Δpimt mutant strain shows defective motility, reduced biofilm formation, and defective invasion and intramacrophage survival. Transcomplementation resulted in partial phenotype (like defective motility, biofilm formation and invasion and intramacrophage survival) restoration of Δpimt mutant strain. Interestingly, supplementation of Δpimt mutant strain culture with reduced glutathione (GSH) resulted in neutralization of ROS and rescued the defective motility and biofilm formation of the mutant strain.
Additional Links: PMID-42419532
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PubMed:
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@article {pmid42419532,
year = {2026},
author = {Mahindhan, R and Chauhan, TKS and Bishnoi, S and Upreti, S and Kumar, M and Pandey, S and Kanwar, C and Pamei, J and Chandra, D and Irungbam, K and Qureshi, S and Mahawar, M},
title = {Transcriptomics and functional analysis reveal impaired motility, biofilm formation, invasion and intramacrophage survival of pimt gene-deleted strain of Salmonella Typhimurium.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {153378},
doi = {10.1016/j.ijbiomac.2026.153378},
pmid = {42419532},
issn = {1879-0003},
abstract = {Inside the host, Salmonella suffers but survives various stresses. Proteins are the prime targets of host inflammatory responses. Salmonella encodes two key protein repair enzymes, methionine sulfoxide reductase (Msr) and protein isoaspartate methyltransferase (PIMT), that reactivates damaged proteins without their translational synthesis. Under stress, the accumulation of L-isoaspartate (isoAsp) residues causes defects in protein shape and function, which lead to impaired bacterial survival. The PIMT converts the isoAsp residues into Asp residues. Earlier, we observed hypersensitivity of Δpimt mutant strain to various stresses and defective colonisation in mice and poultry. Here, we show that Δpimt mutant strain accumulates about 1.67-fold more intracellular ROS levels and higher protein aggregations. RNA-seq analysis of the pimt gene-deleted strain of S. typhimurium revealed differential expression of 2676 genes. Most of the downregulated genes are related to flagellar assembly, chemotaxis, fimbria formation, Salmonella pathogenicity island encoding type-3 secretion system, mainly implicated in motility, adhesion, invasion and intracellular survival inside intestinal epithelium, phagocytic cells, etc. These factors are known to be the major contributors for the virulence of S. typhimurium inside the host. The functional analysis revealed that the Δpimt mutant strain shows defective motility, reduced biofilm formation, and defective invasion and intramacrophage survival. Transcomplementation resulted in partial phenotype (like defective motility, biofilm formation and invasion and intramacrophage survival) restoration of Δpimt mutant strain. Interestingly, supplementation of Δpimt mutant strain culture with reduced glutathione (GSH) resulted in neutralization of ROS and rescued the defective motility and biofilm formation of the mutant strain.},
}
RevDate: 2026-07-07
Hydrolases enzymes for oral biofilm reduction: Lipase, lysozyme, and amylase as promising candidates for canine oral health applications.
International journal of biological macromolecules pii:S0141-8130(26)03338-6 [Epub ahead of print].
Oral biofilms are common in dogs and are a major cause of periodontal disease with potential systemic effects, largely due to the limited efficacy of conventional oral antiseptics against the extracellular matrix. Enzymatic degradation has emerged as a promising alternative approach that directly targets this structure. This study evaluated the individual and combined activities of four enzymes, lipase from Burkholderia cepacia (BC lipase), lipase from Candida rugosa (CR lipase), α-amylase from Bacillus licheniformis, and egg white lysozyme, against monospecies biofilms formed by eight oral-associated bacterial species (Corynebacterium amycolatum, Corynebacterium ulcerans, Streptococcus canis, Enterococcus faecalis, Pasteurella multocida, Moraxella bovis, Escherichia coli, and Stenotrophomonas maltophilia). Biofilm structural changes were analyzed by scanning electron microscopy (SEM), and cytotoxicity was assessed in HaCaT keratinocytes and gingival fibroblasts. BC lipase (40 U/mL) exhibited the broadest antibiofilm activity among the tested enzymes, achieving up to 96% biofilm reduction in S. maltophilia, 87% in E. faecalis, and over 70% in M. bovis and S. canis. Enzymatic treatments were more effective than chlorhexidine for most species. SEM revealed significant reductions in biofilm density and increased colony dispersion, particularly after treatment with BC lipase (40 U/mL). Enzyme combinations showed species-dependent effects, with additive interactions for lipase and antagonistic effects for amylase-containing mixtures. All enzymes maintained high oral cell viability (>97%), whereas chlorhexidine significantly reduced viability. Overall, the enzymes demonstrated the ability to degrade bacterial biofilms without cytotoxic effects, supporting their potential use as green alternatives for controlling canine oral biofilms.
Additional Links: PMID-42413676
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PubMed:
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@article {pmid42413676,
year = {2026},
author = {Cardoso, LT and Nadalon, AC and Til, BB and Visioli, F and Siqueira, FM and Bussamara, R},
title = {Hydrolases enzymes for oral biofilm reduction: Lipase, lysozyme, and amylase as promising candidates for canine oral health applications.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {153398},
doi = {10.1016/j.ijbiomac.2026.153398},
pmid = {42413676},
issn = {1879-0003},
abstract = {Oral biofilms are common in dogs and are a major cause of periodontal disease with potential systemic effects, largely due to the limited efficacy of conventional oral antiseptics against the extracellular matrix. Enzymatic degradation has emerged as a promising alternative approach that directly targets this structure. This study evaluated the individual and combined activities of four enzymes, lipase from Burkholderia cepacia (BC lipase), lipase from Candida rugosa (CR lipase), α-amylase from Bacillus licheniformis, and egg white lysozyme, against monospecies biofilms formed by eight oral-associated bacterial species (Corynebacterium amycolatum, Corynebacterium ulcerans, Streptococcus canis, Enterococcus faecalis, Pasteurella multocida, Moraxella bovis, Escherichia coli, and Stenotrophomonas maltophilia). Biofilm structural changes were analyzed by scanning electron microscopy (SEM), and cytotoxicity was assessed in HaCaT keratinocytes and gingival fibroblasts. BC lipase (40 U/mL) exhibited the broadest antibiofilm activity among the tested enzymes, achieving up to 96% biofilm reduction in S. maltophilia, 87% in E. faecalis, and over 70% in M. bovis and S. canis. Enzymatic treatments were more effective than chlorhexidine for most species. SEM revealed significant reductions in biofilm density and increased colony dispersion, particularly after treatment with BC lipase (40 U/mL). Enzyme combinations showed species-dependent effects, with additive interactions for lipase and antagonistic effects for amylase-containing mixtures. All enzymes maintained high oral cell viability (>97%), whereas chlorhexidine significantly reduced viability. Overall, the enzymes demonstrated the ability to degrade bacterial biofilms without cytotoxic effects, supporting their potential use as green alternatives for controlling canine oral biofilms.},
}
RevDate: 2026-07-08
Impact of biofilm formation on mortality in Candida tropicalis candidaemia: A retrospective study of ICU and Non-ICU patients.
Indian journal of medical microbiology, 63:101205 pii:S0255-0857(26)00163-5 [Epub ahead of print].
PURPOSE: To investigate the clinical factors associated with biofilm formation in Candida tropicalis bloodstream infections and to evaluate its impact on patient mortality in a high-prevalence setting in Thailand.
MATERIALS AND METHODS: We retrospectively analysed 146 episodes (from 145 patients) of C. tropicalis candidaemia at a Thai referral centre (2015-2019). Biofilm formation was quantified by XTT assay and classified as low, moderate, or high. Clinical predictors of high biofilm formation (HBF) and associations with 30-day mortality were evaluated using regression and Kaplan-Meier analyses.
RESULTS: Forty-nine isolates (33.6%) were HBF. Independent risk factors for HBF included shorter hospital stay prior to candidaemia (OR 0.98; 95% CI 0.96-0.999; P = 0.037) and recent Clostridioides difficile infection (OR 14.55; 95% CI 1.58-133.75; P = 0.018). Overall 30-day mortality was 74.0% and did not differ between HBF and non-HBF isolates (77.6% vs. 72.2%; P = 0.484). However, in non-ICU episodes, HBF was associated with significantly lower survival, whereas outcomes in ICU episodes were similar regardless of biofilm capacity.
CONCLUSIONS: Biofilm formation in C. tropicalis candidaemia was linked to recent C. difficile infection and earlier onset of bloodstream infection, and predicted poorer survival in non-ICU episodes.
Additional Links: PMID-42413869
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@article {pmid42413869,
year = {2026},
author = {Leepattarakit, T and Tulyaprawat, O and Mongkudkarn, A and Ngamskulrungroj, P},
title = {Impact of biofilm formation on mortality in Candida tropicalis candidaemia: A retrospective study of ICU and Non-ICU patients.},
journal = {Indian journal of medical microbiology},
volume = {63},
number = {},
pages = {101205},
doi = {10.1016/j.ijmmb.2026.101205},
pmid = {42413869},
issn = {1998-3646},
abstract = {PURPOSE: To investigate the clinical factors associated with biofilm formation in Candida tropicalis bloodstream infections and to evaluate its impact on patient mortality in a high-prevalence setting in Thailand.
MATERIALS AND METHODS: We retrospectively analysed 146 episodes (from 145 patients) of C. tropicalis candidaemia at a Thai referral centre (2015-2019). Biofilm formation was quantified by XTT assay and classified as low, moderate, or high. Clinical predictors of high biofilm formation (HBF) and associations with 30-day mortality were evaluated using regression and Kaplan-Meier analyses.
RESULTS: Forty-nine isolates (33.6%) were HBF. Independent risk factors for HBF included shorter hospital stay prior to candidaemia (OR 0.98; 95% CI 0.96-0.999; P = 0.037) and recent Clostridioides difficile infection (OR 14.55; 95% CI 1.58-133.75; P = 0.018). Overall 30-day mortality was 74.0% and did not differ between HBF and non-HBF isolates (77.6% vs. 72.2%; P = 0.484). However, in non-ICU episodes, HBF was associated with significantly lower survival, whereas outcomes in ICU episodes were similar regardless of biofilm capacity.
CONCLUSIONS: Biofilm formation in C. tropicalis candidaemia was linked to recent C. difficile infection and earlier onset of bloodstream infection, and predicted poorer survival in non-ICU episodes.},
}
RevDate: 2026-07-07
Therapeutic potential of Citrus medica L. (cv. 'Liscia' and cv. 'Rugosa') phytocompounds targeting biofilm formation, quorum sensing, and antioxidant defense mechanisms.
Scientific reports pii:10.1038/s41598-026-60228-z [Epub ahead of print].
Microbial biofilm, quorum sensing (QS)-mediated virulence and oxidative stress-induced inflammation are interrelated pathological processes that play a crucial role in persistent infections and chronic illnesses. Due to the multifactorially of such processes, isolated target-based approaches to therapy usually do not provide long-term effectiveness. A combined network pharmacology and multi-level computational approach was used in order to clarify the molecular mechanisms underlying the antibiofilm, anti-quorum sensing (anti-QS), and antioxidant activities of thirty-three bioactive compounds found in the essential oils (EOs) of Citrus medica cv. Liscia and cv. Rugosa. Human potential protein targets were predicted and intersected with disease-associated genes, and 317 common targets were obtained, which were further viewed in terms of protein-protein interaction network and hub gene. The analysis of the functional enrichment demonstrated that the targets play a large role in oxidative stress response, homeostasis of inflammatory response, signal transduction, apoptosis, and membrane-related processes. Molecular docking analysis reveals strong and consistent binding affinities of aromadendrene, germacrene D, caryophyllene oxide, and carvacrol to major hub proteins such as HSP90AA1, AKT1, TNF, IL6, IL1B, and STAT3. Principal component and secondary structure analysis, and molecular dynamics simulations were used to further assess the HSP90AA1-aromadendrene complex, which was found to be among the most stable complexes. Analysis based on density functional theory was used to support good electronic properties and chemical stability of the lead compound and ADMET profiling revealed acceptable pharmacokinetics and drug-like properties. All these findings indicate a multi-target, multi-pathway therapeutic paradigm and constitute a powerful computational framework of Citrus-based agents against biofilm-associated infections and oxidative stress-related disorders.
Additional Links: PMID-42414432
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PubMed:
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@article {pmid42414432,
year = {2026},
author = {Noumi, E and Alabbosh, KF and Alsenani, Q and Alshammari, N and Alshammari, M and Adnan, M and Ceylan, O and Kadri, A and Snoussi, M and De Feo, V},
title = {Therapeutic potential of Citrus medica L. (cv. 'Liscia' and cv. 'Rugosa') phytocompounds targeting biofilm formation, quorum sensing, and antioxidant defense mechanisms.},
journal = {Scientific reports},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41598-026-60228-z},
pmid = {42414432},
issn = {2045-2322},
support = {<RG-25 095>//This research has been funded by Scientific Research Deanship at University of Ha'il- Saudi Arabia through project number/ ; },
abstract = {Microbial biofilm, quorum sensing (QS)-mediated virulence and oxidative stress-induced inflammation are interrelated pathological processes that play a crucial role in persistent infections and chronic illnesses. Due to the multifactorially of such processes, isolated target-based approaches to therapy usually do not provide long-term effectiveness. A combined network pharmacology and multi-level computational approach was used in order to clarify the molecular mechanisms underlying the antibiofilm, anti-quorum sensing (anti-QS), and antioxidant activities of thirty-three bioactive compounds found in the essential oils (EOs) of Citrus medica cv. Liscia and cv. Rugosa. Human potential protein targets were predicted and intersected with disease-associated genes, and 317 common targets were obtained, which were further viewed in terms of protein-protein interaction network and hub gene. The analysis of the functional enrichment demonstrated that the targets play a large role in oxidative stress response, homeostasis of inflammatory response, signal transduction, apoptosis, and membrane-related processes. Molecular docking analysis reveals strong and consistent binding affinities of aromadendrene, germacrene D, caryophyllene oxide, and carvacrol to major hub proteins such as HSP90AA1, AKT1, TNF, IL6, IL1B, and STAT3. Principal component and secondary structure analysis, and molecular dynamics simulations were used to further assess the HSP90AA1-aromadendrene complex, which was found to be among the most stable complexes. Analysis based on density functional theory was used to support good electronic properties and chemical stability of the lead compound and ADMET profiling revealed acceptable pharmacokinetics and drug-like properties. All these findings indicate a multi-target, multi-pathway therapeutic paradigm and constitute a powerful computational framework of Citrus-based agents against biofilm-associated infections and oxidative stress-related disorders.},
}
RevDate: 2026-07-07
Self-generated hydrogel ejects bacterial cells for localized biofilm dispersion.
Nature microbiology [Epub ahead of print].
Bacteria residing in biofilms are embedded in an extracellular matrix. Whereas biofilm formation is well studied, less is known about biofilm dispersion, although enzymatic extracellular matrix degradation is suspected to play a key role. Here we show that Bacillus subtilis biofilms can alternatively eject a specific cell type, locally and anisotropically, using mechanical forces arising from a self-generated hydrogel. Single-cell resolution imaging combined with mathematical modelling, and chemical and genetic perturbations, show that the production of the extracellular poly-γ-glutamic acid (γ-PGA) polymer is necessary to drive this cell ejection. Specifically, osmotic pressure from the γ-PGA hydrogel propels interior cells through the outer layers to break free from the biofilm. We demonstrate control over this process through γ-PGA modulation such that biofilm dispersion can be either inhibited or promoted. Forceful ejection driven by γ-PGA has so far only been described in marine organisms such as jellyfish. Our discovery of biofilm cell ejection via γ-PGA thus reveals not only a previously uncharacterized biofilm dispersion mechanism but also an unexpected mechanistic parallel to evolutionarily distant Cnidaria.
Additional Links: PMID-42414588
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@article {pmid42414588,
year = {2026},
author = {Chou, TK and Dau-Martinez, A and Vicens-Figueres, J and Gouttumukkala, A and Galera-Laporta, L and Garcia-Ojalvo, J and Süel, GM},
title = {Self-generated hydrogel ejects bacterial cells for localized biofilm dispersion.},
journal = {Nature microbiology},
volume = {},
number = {},
pages = {},
pmid = {42414588},
issn = {2058-5276},
support = {T32GM127235//U.S. Department of Health & Human Services | National Institutes of Health (NIH)/ ; R35GM139645//U.S. Department of Health & Human Services | National Institutes of Health (NIH)/ ; W911NF-22-1-0107 and W911NF-1-0361//United States Department of Defense | United States Army | U.S. Army Research, Development and Engineering Command | Army Research Office (ARO)/ ; INV-067331//Bill and Melinda Gates Foundation (Bill & Melinda Gates Foundation)/ ; },
abstract = {Bacteria residing in biofilms are embedded in an extracellular matrix. Whereas biofilm formation is well studied, less is known about biofilm dispersion, although enzymatic extracellular matrix degradation is suspected to play a key role. Here we show that Bacillus subtilis biofilms can alternatively eject a specific cell type, locally and anisotropically, using mechanical forces arising from a self-generated hydrogel. Single-cell resolution imaging combined with mathematical modelling, and chemical and genetic perturbations, show that the production of the extracellular poly-γ-glutamic acid (γ-PGA) polymer is necessary to drive this cell ejection. Specifically, osmotic pressure from the γ-PGA hydrogel propels interior cells through the outer layers to break free from the biofilm. We demonstrate control over this process through γ-PGA modulation such that biofilm dispersion can be either inhibited or promoted. Forceful ejection driven by γ-PGA has so far only been described in marine organisms such as jellyfish. Our discovery of biofilm cell ejection via γ-PGA thus reveals not only a previously uncharacterized biofilm dispersion mechanism but also an unexpected mechanistic parallel to evolutionarily distant Cnidaria.},
}
RevDate: 2026-07-08
CmpDate: 2026-07-08
Streptococcus thermophilus DM287 and DM294 as candidate oral probiotic strains with anti-biofilm activity against cariogenic pathogens.
Frontiers in microbiology, 17:1852167.
Streptococcus mutans and Streptococcus sobrinus are key contributors to dental caries within a broader polymicrobial biofilm community, driving pathogenicity through biofilm and dental plaque formation rather than direct tissue invasion. Probiotic-based strategies that target colonization rather than viability represent a promising non-antibiotic approach to caries prevention. Streptococcus thermophilus is a food-grade organism with established GRAS status and a long history of safe human consumption, yet it remains largely unexplored as an oral care ingredient. In this study, two S. thermophilus strains - DM287, isolated from a commercially available yogurt product, and DM294, isolated from the tongue coat of healthy adults - were characterized for anti-cariogenic activity through mechanisms independent of major pathogen abundance reduction. Both strains reduced plaque mass by approximately 75%-80% in a wire model assay and suppressed S. mutans and S. sobrinus biofilm biomass to near-baseline levels, while planktonic growth suggested that the observed effects were not primarily driven by bactericidal activity. Adhesion inhibition assays showed 32%-64% reduction in pathogen adhesion under protection conditions and 72%-76% under displacement conditions. Competitive colonization assays demonstrated that both strains increased surface attachment in pathogen-conditioned environments (fold change > 1.0), consistent with competitive displacement behavior. RT-qPCR analysis of S. mutans biofilms co-cultured with either strain revealed significant downregulation of gtfB and gtfC - key glucosyltransferase genes encoding the EPS synthetic machinery central to biofilm structure - with reductions of approximately 34%-63% depending on the strain and time point, suggesting transcriptional suppression of biofilm-associated virulence as a contributing mechanism. EPS quantification by phenol-sulfuric acid assay further demonstrated that both strains reduced EPS production by 80%-90%, a magnitude comparable to chlorhexidine and substantially exceeding that of Lacticaseibacillus rhamnosus GG. Taken together, these findings suggest that S. thermophilus DM287 and DM294 are biocompatible candidate strains with promising anti-biofilm potential for oral care applications, pending further validation.
Additional Links: PMID-42416019
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Citation:
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@article {pmid42416019,
year = {2026},
author = {Lee, JH and Yoo, J and Eom, JH and Kim, YY and Kim, HS and Yang, SJ},
title = {Streptococcus thermophilus DM287 and DM294 as candidate oral probiotic strains with anti-biofilm activity against cariogenic pathogens.},
journal = {Frontiers in microbiology},
volume = {17},
number = {},
pages = {1852167},
pmid = {42416019},
issn = {1664-302X},
abstract = {Streptococcus mutans and Streptococcus sobrinus are key contributors to dental caries within a broader polymicrobial biofilm community, driving pathogenicity through biofilm and dental plaque formation rather than direct tissue invasion. Probiotic-based strategies that target colonization rather than viability represent a promising non-antibiotic approach to caries prevention. Streptococcus thermophilus is a food-grade organism with established GRAS status and a long history of safe human consumption, yet it remains largely unexplored as an oral care ingredient. In this study, two S. thermophilus strains - DM287, isolated from a commercially available yogurt product, and DM294, isolated from the tongue coat of healthy adults - were characterized for anti-cariogenic activity through mechanisms independent of major pathogen abundance reduction. Both strains reduced plaque mass by approximately 75%-80% in a wire model assay and suppressed S. mutans and S. sobrinus biofilm biomass to near-baseline levels, while planktonic growth suggested that the observed effects were not primarily driven by bactericidal activity. Adhesion inhibition assays showed 32%-64% reduction in pathogen adhesion under protection conditions and 72%-76% under displacement conditions. Competitive colonization assays demonstrated that both strains increased surface attachment in pathogen-conditioned environments (fold change > 1.0), consistent with competitive displacement behavior. RT-qPCR analysis of S. mutans biofilms co-cultured with either strain revealed significant downregulation of gtfB and gtfC - key glucosyltransferase genes encoding the EPS synthetic machinery central to biofilm structure - with reductions of approximately 34%-63% depending on the strain and time point, suggesting transcriptional suppression of biofilm-associated virulence as a contributing mechanism. EPS quantification by phenol-sulfuric acid assay further demonstrated that both strains reduced EPS production by 80%-90%, a magnitude comparable to chlorhexidine and substantially exceeding that of Lacticaseibacillus rhamnosus GG. Taken together, these findings suggest that S. thermophilus DM287 and DM294 are biocompatible candidate strains with promising anti-biofilm potential for oral care applications, pending further validation.},
}
RevDate: 2026-07-08
A biomimetic cascade nanoplatform for synergistic biofilm eradication and immune activation against MRSA.
RSC advances [Epub ahead of print].
Methicillin-resistant Staphylococcus aureus (MRSA) biofilm-associated infections remain a formidable clinical challenge, owing to limited antibiotic penetration, an immunosuppressive microenvironment, and recurrent biofilm regeneration. Effective long-term immunomodulatory strategies to prevent reinfection are still lacking. To address this issue, we have constructed a biomimetic cascade nanoplatform (MACP@DG@CM) that integrates a photothermal nanozyme core, surface-anchored DNase I-functionalized gold nanoclusters (DNase I-GNCs), and a pre-activated macrophage membrane camouflage. This design enables synergistic biofilm eradication and immune microenvironment modulation. Under an 808 nm near-infrared (NIR) irradiation, the nanoplatform triggers a cascade radical storm, including photothermal hyperthermia, a peroxidase-like hydroxyl radical (·OH) burst, nitric oxide (NO) release, and DNase I-mediated extracellular DNA (eDNA) degradation. Concurrently, it depletes glutathione (GSH), disrupts bacterial redox homeostasis, and causes severe membrane damage. Transcriptomic analysis reveals that the nanoplatform perturbs bacterial two-component systems, d-amino acid metabolism, and antimicrobial peptide resistance pathways. Enzyme-linked immunosorbent assay (ELISA) further confirms up-regulated pro-inflammatory cytokines and down-regulated anti-inflammatory cytokines, indicating an activated inflammatory response. In an MRSA-infected wound model, it accelerates wound closure, promotes collagen deposition, and modulates inflammation. Collectively, this biomimetic cascade nanoplatform provides a synergistic strategy for biofilm eradication and immune activation against drug-resistant infections.
Additional Links: PMID-42416706
PubMed:
Citation:
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@article {pmid42416706,
year = {2026},
author = {Liao, C and Liao, J and Nie, X and Chang, Q and Chen, K and Zhong, Z and Tang, H and Wang, D},
title = {A biomimetic cascade nanoplatform for synergistic biofilm eradication and immune activation against MRSA.},
journal = {RSC advances},
volume = {},
number = {},
pages = {},
pmid = {42416706},
issn = {2046-2069},
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) biofilm-associated infections remain a formidable clinical challenge, owing to limited antibiotic penetration, an immunosuppressive microenvironment, and recurrent biofilm regeneration. Effective long-term immunomodulatory strategies to prevent reinfection are still lacking. To address this issue, we have constructed a biomimetic cascade nanoplatform (MACP@DG@CM) that integrates a photothermal nanozyme core, surface-anchored DNase I-functionalized gold nanoclusters (DNase I-GNCs), and a pre-activated macrophage membrane camouflage. This design enables synergistic biofilm eradication and immune microenvironment modulation. Under an 808 nm near-infrared (NIR) irradiation, the nanoplatform triggers a cascade radical storm, including photothermal hyperthermia, a peroxidase-like hydroxyl radical (·OH) burst, nitric oxide (NO) release, and DNase I-mediated extracellular DNA (eDNA) degradation. Concurrently, it depletes glutathione (GSH), disrupts bacterial redox homeostasis, and causes severe membrane damage. Transcriptomic analysis reveals that the nanoplatform perturbs bacterial two-component systems, d-amino acid metabolism, and antimicrobial peptide resistance pathways. Enzyme-linked immunosorbent assay (ELISA) further confirms up-regulated pro-inflammatory cytokines and down-regulated anti-inflammatory cytokines, indicating an activated inflammatory response. In an MRSA-infected wound model, it accelerates wound closure, promotes collagen deposition, and modulates inflammation. Collectively, this biomimetic cascade nanoplatform provides a synergistic strategy for biofilm eradication and immune activation against drug-resistant infections.},
}
RevDate: 2026-07-06
CmpDate: 2026-07-06
Aloin of Aloe vera disrupts pseudomonas aeruginosa biofilm formation: exploring nutritional therapeutics.
Archives of microbiology, 208(9):.
Pseudomonas aeruginosa is responsible for several infections due to its remarkable antibiotic resistance, facilitated by its ability to form biofilms. In this study, Aloin, an anthraquinone present in the plant Aloe vera, was tested for antibiofilm activity against P. aeruginosa PAO1. Aloin demonstrated efficient biofilm-inhibiting capacity at a sub-MIC dose of 4.8 mM, along with/without GEN at 0.002 µg/µL (sub-MIC), in an additive manner, determined by the FICI test. Furthermore, it reduced biofilm-associated carbohydrates by 66.9%, proteins by 66.22%, and extracellular DNA by 69.57%. In silico analysis revealed that Aloin interacts with key P. aeruginosa proteins, such as RhlI (Glide Score: -6.035 kcal/mol; Glide e-model score: -60.414 kcal/mol), LasI (Glide Score: -4.407 kcal/mol; Glide e-model score: -35.286 kcal/mol), LasR (chain A) (Glide Score: -3.764 kcal/mol; Glide e-model score: -36.012 kcal/mol), LasR (chain B) (Glide Score: -5.015 kcal/mol; Glide e-model score: -46.672 kcal/mol), PqsR (Glide Score: -4.701 kcal/mol; Glide e-model score: -25.491 kcal/mol), PelA (Glide Score: -6.097 kcal/mol; Glide e-model score: -53.723 kcal/mol), and PelB (Glide Score: -5.043 kcal/mol; Glide e-model score: -53.128 kcal/mol) by forming strong hydrogen bonds. In silico simulation studies also substantiated the Aloin-protein binding results. The production of virulence factors, such as exoprotease and pyocyanin, was reduced by 71% and 74%, respectively. Furthermore, CLSM and SEM analysis showed a decrease in biofilm thickness from 498 μm to 72 μm and a reduced denser structure in the presence of Aloin. These results suggest that Aloin from Aloe vera has the potential to be an effective biofilm inhibitor without toxicity, with broad applicability.
Additional Links: PMID-42406057
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Citation:
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@article {pmid42406057,
year = {2026},
author = {Panigrahi, S and Roy, DN},
title = {Aloin of Aloe vera disrupts pseudomonas aeruginosa biofilm formation: exploring nutritional therapeutics.},
journal = {Archives of microbiology},
volume = {208},
number = {9},
pages = {},
pmid = {42406057},
issn = {1432-072X},
mesh = {*Biofilms/drug effects/growth & development ; *Pseudomonas aeruginosa/drug effects/physiology/genetics ; *Aloe/chemistry ; *Emodin/analogs & derivatives/pharmacology/chemistry ; Bacterial Proteins/metabolism/genetics/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry ; Microbial Sensitivity Tests ; Molecular Docking Simulation ; },
abstract = {Pseudomonas aeruginosa is responsible for several infections due to its remarkable antibiotic resistance, facilitated by its ability to form biofilms. In this study, Aloin, an anthraquinone present in the plant Aloe vera, was tested for antibiofilm activity against P. aeruginosa PAO1. Aloin demonstrated efficient biofilm-inhibiting capacity at a sub-MIC dose of 4.8 mM, along with/without GEN at 0.002 µg/µL (sub-MIC), in an additive manner, determined by the FICI test. Furthermore, it reduced biofilm-associated carbohydrates by 66.9%, proteins by 66.22%, and extracellular DNA by 69.57%. In silico analysis revealed that Aloin interacts with key P. aeruginosa proteins, such as RhlI (Glide Score: -6.035 kcal/mol; Glide e-model score: -60.414 kcal/mol), LasI (Glide Score: -4.407 kcal/mol; Glide e-model score: -35.286 kcal/mol), LasR (chain A) (Glide Score: -3.764 kcal/mol; Glide e-model score: -36.012 kcal/mol), LasR (chain B) (Glide Score: -5.015 kcal/mol; Glide e-model score: -46.672 kcal/mol), PqsR (Glide Score: -4.701 kcal/mol; Glide e-model score: -25.491 kcal/mol), PelA (Glide Score: -6.097 kcal/mol; Glide e-model score: -53.723 kcal/mol), and PelB (Glide Score: -5.043 kcal/mol; Glide e-model score: -53.128 kcal/mol) by forming strong hydrogen bonds. In silico simulation studies also substantiated the Aloin-protein binding results. The production of virulence factors, such as exoprotease and pyocyanin, was reduced by 71% and 74%, respectively. Furthermore, CLSM and SEM analysis showed a decrease in biofilm thickness from 498 μm to 72 μm and a reduced denser structure in the presence of Aloin. These results suggest that Aloin from Aloe vera has the potential to be an effective biofilm inhibitor without toxicity, with broad applicability.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Pseudomonas aeruginosa/drug effects/physiology/genetics
*Aloe/chemistry
*Emodin/analogs & derivatives/pharmacology/chemistry
Bacterial Proteins/metabolism/genetics/chemistry
*Anti-Bacterial Agents/pharmacology/chemistry
Microbial Sensitivity Tests
Molecular Docking Simulation
RevDate: 2026-07-06
CmpDate: 2026-07-06
Methamphetamine promotes methicillin-resistant Staphylococcus aureus subcutaneous infection through innate immune dysregulation and altered expression of biofilm-associated genes.
Microbiology (Reading, England), 172(7):.
Methamphetamine (METH) use is associated with an elevated risk of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA), yet its direct effects on MRSA pathogenesis remain poorly characterized. Using a BALB/c murine subcutaneous infection model, we demonstrate that METH significantly increases abscess area and bacterial burden compared to untreated controls. Histological analysis revealed markedly elevated neutrophil infiltration and a concurrent reduction in macrophage recruitment in METH-treated animals, indicating dysregulation of innate immune coordination at the infection site. METH exposure was also associated with increased expression of fga and col1, which are responsible for fibrinogen and collagen I production, respectively, consistent with profibrotic extracellular matrix remodelling that may scaffold bacterial persistence and impair immune effector access. At the molecular level, METH increased the expression of the icaA locus, which is required for polysaccharide intercellular adhesin synthesis and biofilm formation, compared to untreated MRSA-infected controls. Conversely, METH suppressed the sepA locus, suggesting a shift toward localized MRSA persistence within the abscess environment. Together, these results demonstrate that METH exacerbates MRSA subcutaneous infection in vivo through higher profibrotic host transcript levels, enhanced biofilm gene expression and dysregulated innate immunity. These findings provide a framework for future studies investigating how METH exposure shapes MRSA disease severity.
Additional Links: PMID-42406614
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@article {pmid42406614,
year = {2026},
author = {Jewth, R and Elgammal, Y and Lee, HH and Martinez, LR},
title = {Methamphetamine promotes methicillin-resistant Staphylococcus aureus subcutaneous infection through innate immune dysregulation and altered expression of biofilm-associated genes.},
journal = {Microbiology (Reading, England)},
volume = {172},
number = {7},
pages = {},
doi = {10.1099/mic.0.001732},
pmid = {42406614},
issn = {1465-2080},
mesh = {Animals ; *Methicillin-Resistant Staphylococcus aureus/drug effects/genetics/physiology/immunology/pathogenicity ; *Biofilms/drug effects/growth & development ; *Immunity, Innate/drug effects ; Mice, Inbred BALB C ; *Methamphetamine/adverse effects ; Mice ; Disease Models, Animal ; *Staphylococcal Infections/immunology/microbiology ; Abscess/microbiology ; *Staphylococcal Skin Infections/microbiology/immunology ; Female ; },
abstract = {Methamphetamine (METH) use is associated with an elevated risk of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA), yet its direct effects on MRSA pathogenesis remain poorly characterized. Using a BALB/c murine subcutaneous infection model, we demonstrate that METH significantly increases abscess area and bacterial burden compared to untreated controls. Histological analysis revealed markedly elevated neutrophil infiltration and a concurrent reduction in macrophage recruitment in METH-treated animals, indicating dysregulation of innate immune coordination at the infection site. METH exposure was also associated with increased expression of fga and col1, which are responsible for fibrinogen and collagen I production, respectively, consistent with profibrotic extracellular matrix remodelling that may scaffold bacterial persistence and impair immune effector access. At the molecular level, METH increased the expression of the icaA locus, which is required for polysaccharide intercellular adhesin synthesis and biofilm formation, compared to untreated MRSA-infected controls. Conversely, METH suppressed the sepA locus, suggesting a shift toward localized MRSA persistence within the abscess environment. Together, these results demonstrate that METH exacerbates MRSA subcutaneous infection in vivo through higher profibrotic host transcript levels, enhanced biofilm gene expression and dysregulated innate immunity. These findings provide a framework for future studies investigating how METH exposure shapes MRSA disease severity.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Animals
*Methicillin-Resistant Staphylococcus aureus/drug effects/genetics/physiology/immunology/pathogenicity
*Biofilms/drug effects/growth & development
*Immunity, Innate/drug effects
Mice, Inbred BALB C
*Methamphetamine/adverse effects
Mice
Disease Models, Animal
*Staphylococcal Infections/immunology/microbiology
Abscess/microbiology
*Staphylococcal Skin Infections/microbiology/immunology
Female
RevDate: 2026-07-06
CmpDate: 2026-07-07
Magnetically actuated microrobotic system for sequential treatment of biofilm.
Proceedings of the National Academy of Sciences of the United States of America, 123(28):e2535216123.
Biofilm-associated infections present a critical therapeutic challenge due to antibiotic resistance and impaired tissue healing. Here, we present a microrobotic system (MZ-8) that integrates real-time human-steered navigation with autonomous, microenvironment-responsive therapy to actively eradicate biofilms and promote tissue regeneration. This microrobotic system features a spine-inspired structure for mechanical biofilm disruption, a pH-responsive ZIF-8 coating for immunomodulatory Zn[2+] release, and closed-loop actuation under second near-infrared fluorescence guidance. In a rat model of periprosthetic joint infection, MZ-8 achieved effective biofilm removal, induced a pro-regenerative immune response by polarizing macrophages toward the M2 phenotype, and significantly enhanced tissue regeneration. Transcriptomic analysis further revealed the activation of immunomodulatory pathways and upregulation of M2-associated genes, confirming the system's sequential shift from eradication to repair. Moreover, validation in a rabbit model and human knee joint confirmed its operational feasibility under clinical imaging guidance and excellent biosafety. This work establishes that integrating physical eradication, biochemical immunomodulation, and interactive control within a single system is essential for advancing from infection clearance to functional tissue restoration. Thus, it provides a therapeutic paradigm for biofilm-associated diseases and lays a foundation for future intelligent, clinically adaptive anti-infective systems.
Additional Links: PMID-42406953
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PubMed:
Citation:
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@article {pmid42406953,
year = {2026},
author = {Li, S and Mei, Y and Xu, K and Sheng, H and Chen, YA and Teng, M and Xu, B and Jiang, B and Yu, C and Li, H and Zhao, S and Wang, Y and Zhang, X and Zhao, Y and Wang, Y and Wo, Y and Li, Z and Shen, S and Li, Y and Tang, M and Mei, Y and Chen, J and Huang, G and Feng, S},
title = {Magnetically actuated microrobotic system for sequential treatment of biofilm.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {123},
number = {28},
pages = {e2535216123},
doi = {10.1073/pnas.2535216123},
pmid = {42406953},
issn = {1091-6490},
mesh = {*Biofilms/drug effects ; Animals ; Rabbits ; Humans ; Rats ; *Robotics/instrumentation/methods ; *Prosthesis-Related Infections/microbiology/therapy ; Zinc ; Staphylococcal Infections ; Anti-Bacterial Agents/pharmacology ; Macrophages/immunology ; },
abstract = {Biofilm-associated infections present a critical therapeutic challenge due to antibiotic resistance and impaired tissue healing. Here, we present a microrobotic system (MZ-8) that integrates real-time human-steered navigation with autonomous, microenvironment-responsive therapy to actively eradicate biofilms and promote tissue regeneration. This microrobotic system features a spine-inspired structure for mechanical biofilm disruption, a pH-responsive ZIF-8 coating for immunomodulatory Zn[2+] release, and closed-loop actuation under second near-infrared fluorescence guidance. In a rat model of periprosthetic joint infection, MZ-8 achieved effective biofilm removal, induced a pro-regenerative immune response by polarizing macrophages toward the M2 phenotype, and significantly enhanced tissue regeneration. Transcriptomic analysis further revealed the activation of immunomodulatory pathways and upregulation of M2-associated genes, confirming the system's sequential shift from eradication to repair. Moreover, validation in a rabbit model and human knee joint confirmed its operational feasibility under clinical imaging guidance and excellent biosafety. This work establishes that integrating physical eradication, biochemical immunomodulation, and interactive control within a single system is essential for advancing from infection clearance to functional tissue restoration. Thus, it provides a therapeutic paradigm for biofilm-associated diseases and lays a foundation for future intelligent, clinically adaptive anti-infective systems.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
Animals
Rabbits
Humans
Rats
*Robotics/instrumentation/methods
*Prosthesis-Related Infections/microbiology/therapy
Zinc
Staphylococcal Infections
Anti-Bacterial Agents/pharmacology
Macrophages/immunology
RevDate: 2026-07-06
Synthesis of zinc oxide nanoparticles and their effect on biofilm of methicillin-resistant Staphylococcus aureus isolates.
BMC microbiology pii:10.1186/s12866-026-05382-0 [Epub ahead of print].
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) poses a growing threat in Iranian healthcare settings, and biofilm formation exacerbates treatment challenges. This study assessed the antibacterial and anti-biofilm potential of zinc oxide nanoparticles ZnONPs against 58 clinical MRSA isolates collected from hospitals in Iran.
METHODS: Isolates were identified via microbial and biochemical tests and confirmed by PCR targeting nuc (279 bp) and mecA (310 bp) genes. Antimicrobial susceptibility was evaluated using CLSI disk diffusion guidelines. The ZnONPs were synthesized by chemical precipitation. Minimum inhibitory concentrations (MICs) of ZnONPs were determined by broth microdilution, and biofilm formation/inhibition was quantified using crystal violet staining.
RESULTS: Of 131 S. aureus isolates, 58 (44.3%) were MRSA, exhibiting high resistance to Penicillin (100%), Erythromycin (91.4%), and Ciprofloxacin (74.1%), but full susceptibility to Trimethoprim-Sulfamethoxazole. ZnONPs displayed potent activity, with MICs ranging from 8 to 1024 µg/mL (MIC₅₀ = 64 µg/mL; MIC₉₀ = 512 µg/mL); 27.6% of isolates were inhibited at ≤ 16 µg/mL. Among MRSA, 15.5% were strong biofilm producers, and sub-MIC (½ MIC) concentrations of ZnONPs reduced biofilm by 82.3 ± 7.6% (P < 0.001). Dynamic light scattering confirmed nanoparticle stability (size: 29.4 ± 4.2 nm; PDI: 0.19).
CONCLUSIONS: These findings highlight ZnONPs as a promising, low-cost alternative for managing MRSA infections, particularly in biofilm-associated cases, warranting further clinical exploration in resource-limited settings.
Additional Links: PMID-42410350
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PubMed:
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@article {pmid42410350,
year = {2026},
author = {Moghaddam, AM and Ahmadishoar, S and Aval, SF},
title = {Synthesis of zinc oxide nanoparticles and their effect on biofilm of methicillin-resistant Staphylococcus aureus isolates.},
journal = {BMC microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1186/s12866-026-05382-0},
pmid = {42410350},
issn = {1471-2180},
abstract = {BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) poses a growing threat in Iranian healthcare settings, and biofilm formation exacerbates treatment challenges. This study assessed the antibacterial and anti-biofilm potential of zinc oxide nanoparticles ZnONPs against 58 clinical MRSA isolates collected from hospitals in Iran.
METHODS: Isolates were identified via microbial and biochemical tests and confirmed by PCR targeting nuc (279 bp) and mecA (310 bp) genes. Antimicrobial susceptibility was evaluated using CLSI disk diffusion guidelines. The ZnONPs were synthesized by chemical precipitation. Minimum inhibitory concentrations (MICs) of ZnONPs were determined by broth microdilution, and biofilm formation/inhibition was quantified using crystal violet staining.
RESULTS: Of 131 S. aureus isolates, 58 (44.3%) were MRSA, exhibiting high resistance to Penicillin (100%), Erythromycin (91.4%), and Ciprofloxacin (74.1%), but full susceptibility to Trimethoprim-Sulfamethoxazole. ZnONPs displayed potent activity, with MICs ranging from 8 to 1024 µg/mL (MIC₅₀ = 64 µg/mL; MIC₉₀ = 512 µg/mL); 27.6% of isolates were inhibited at ≤ 16 µg/mL. Among MRSA, 15.5% were strong biofilm producers, and sub-MIC (½ MIC) concentrations of ZnONPs reduced biofilm by 82.3 ± 7.6% (P < 0.001). Dynamic light scattering confirmed nanoparticle stability (size: 29.4 ± 4.2 nm; PDI: 0.19).
CONCLUSIONS: These findings highlight ZnONPs as a promising, low-cost alternative for managing MRSA infections, particularly in biofilm-associated cases, warranting further clinical exploration in resource-limited settings.},
}
RevDate: 2026-07-07
Biosynthetic composite iron minerals enhance electroactive biofilm activity and stability by reducing charge transfer resistance and buffering the internal acid inhibition.
Bioresource technology pii:S0960-8524(26)01411-2 [Epub ahead of print].
Electroactive biofilms (EAB) enable organic degradation and energy recovery in microbial electrochemical systems (MES). Nevertheless, internal proton accumulation during microbial metabolism impairs EAB activity, while slow electron transfer between EAB and electrodes further limits MES performance. Efficient in-situ strategies to mitigate acidification and accelerate electron transfer are critically required to stabilize EAB performance. Biosynthetic composite iron minerals (BCIM) consisting of Fe3O4 and FeCO3 was synthesized via microbial reduction of amorphous Fe(III) oxyhydroxide, integrating electrical conductivity and proton buffering function. BCIM-modified carbon cloth anodes (1 and 4 mg/cm[2], group C1 and group C4) were evaluated against bare controls. Results showed that the carbon cloth anode loaded with 1 mg/cm[2] BCIM achieved a maximum power density of 1166 mW/m[2], 28% higher than the control group, and cut the startup period from 8 days to 1.6 days. BCIM reduced charge transfer resistance, boosted the bioelectrochemical activity and increased electroactive sites of EAB. Meanwhile, BCIM dramatically raised the relative abundance of Geobacter sp. from 31.1% in the control group to 48.8% in Group C1, and also upregulated the abundance of functional genes associated with pili and flagellum. The FeCO3 component provided localized pH regulation to relieve biofilm proton accumulation and enhance cell activity. With dual functions of accelerating electron transfer and alleviating acidification, BCIM presents a promising material to optimize EAB performance.
Additional Links: PMID-42413590
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PubMed:
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@article {pmid42413590,
year = {2026},
author = {Wang, N and Liang, D and Zhang, Z and Zhu, Y and He, W and Feng, Y},
title = {Biosynthetic composite iron minerals enhance electroactive biofilm activity and stability by reducing charge transfer resistance and buffering the internal acid inhibition.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {135329},
doi = {10.1016/j.biortech.2026.135329},
pmid = {42413590},
issn = {1873-2976},
abstract = {Electroactive biofilms (EAB) enable organic degradation and energy recovery in microbial electrochemical systems (MES). Nevertheless, internal proton accumulation during microbial metabolism impairs EAB activity, while slow electron transfer between EAB and electrodes further limits MES performance. Efficient in-situ strategies to mitigate acidification and accelerate electron transfer are critically required to stabilize EAB performance. Biosynthetic composite iron minerals (BCIM) consisting of Fe3O4 and FeCO3 was synthesized via microbial reduction of amorphous Fe(III) oxyhydroxide, integrating electrical conductivity and proton buffering function. BCIM-modified carbon cloth anodes (1 and 4 mg/cm[2], group C1 and group C4) were evaluated against bare controls. Results showed that the carbon cloth anode loaded with 1 mg/cm[2] BCIM achieved a maximum power density of 1166 mW/m[2], 28% higher than the control group, and cut the startup period from 8 days to 1.6 days. BCIM reduced charge transfer resistance, boosted the bioelectrochemical activity and increased electroactive sites of EAB. Meanwhile, BCIM dramatically raised the relative abundance of Geobacter sp. from 31.1% in the control group to 48.8% in Group C1, and also upregulated the abundance of functional genes associated with pili and flagellum. The FeCO3 component provided localized pH regulation to relieve biofilm proton accumulation and enhance cell activity. With dual functions of accelerating electron transfer and alleviating acidification, BCIM presents a promising material to optimize EAB performance.},
}
RevDate: 2026-07-04
Shear redistribution in confined biofilm systems: decoupling structure and function in engineered water environments.
NPJ biofilms and microbiomes pii:10.1038/s41522-026-01082-9 [Epub ahead of print].
Biofilms in engineered water systems often develop within confined, tortuous flow paths where shear stress is spatially heterogeneous. However, biofilm responses are commonly evaluated using bulk metrics that treat shear as uniform and externally imposed, overlooking how geometric confinement redistributes shear during biofilm growth. Here, we examined how confinement-driven shear redistribution governs biofilm-hydrodynamic interactions in labyrinth microchannels under constant pressure. By integrating time-resolved biofilm-altered geometries with flow simulations, we show that localized biofilm accumulation reorganizes preferential flow pathways, redistributes wall shear stress, and causes a disproportionate decline in discharge. Hydraulic deterioration was increasingly governed by constriction of the remaining effective flow paths rather than by biomass accumulation alone, revealing nonlinear hydraulic sensitivity to spatially localized growth. Controlled-shear experiments further showed that ATP-based physiological indicators remained comparatively stable and peaked at intermediate shear levels, whereas extracellular polymeric substance composition shifted toward higher protein-to-polysaccharide ratios with increasing shear. Together, these results demonstrate a partial decoupling between biofilm structure and activity-related or matrix-compositional indicators under confinement-generated shear redistribution, highlighting the limitations of bulk structural metrics for predicting biofilm behavior and hydraulic performance.
Additional Links: PMID-42401614
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PubMed:
Citation:
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@article {pmid42401614,
year = {2026},
author = {Hou, P and Li, L and Liu, Z and Tao, J and Muhammad, T and Wang, Y and Hu, H and Zang, C and Xiao, Y and Rittmann, BE},
title = {Shear redistribution in confined biofilm systems: decoupling structure and function in engineered water environments.},
journal = {NPJ biofilms and microbiomes},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41522-026-01082-9},
pmid = {42401614},
issn = {2055-5008},
support = {52339004, 52409074, 52209074//National Natural Science Foundation of China/ ; },
abstract = {Biofilms in engineered water systems often develop within confined, tortuous flow paths where shear stress is spatially heterogeneous. However, biofilm responses are commonly evaluated using bulk metrics that treat shear as uniform and externally imposed, overlooking how geometric confinement redistributes shear during biofilm growth. Here, we examined how confinement-driven shear redistribution governs biofilm-hydrodynamic interactions in labyrinth microchannels under constant pressure. By integrating time-resolved biofilm-altered geometries with flow simulations, we show that localized biofilm accumulation reorganizes preferential flow pathways, redistributes wall shear stress, and causes a disproportionate decline in discharge. Hydraulic deterioration was increasingly governed by constriction of the remaining effective flow paths rather than by biomass accumulation alone, revealing nonlinear hydraulic sensitivity to spatially localized growth. Controlled-shear experiments further showed that ATP-based physiological indicators remained comparatively stable and peaked at intermediate shear levels, whereas extracellular polymeric substance composition shifted toward higher protein-to-polysaccharide ratios with increasing shear. Together, these results demonstrate a partial decoupling between biofilm structure and activity-related or matrix-compositional indicators under confinement-generated shear redistribution, highlighting the limitations of bulk structural metrics for predicting biofilm behavior and hydraulic performance.},
}
RevDate: 2026-07-05
The Streptococcus mutans collagen-binding protein Cnm enhances early biofilm formation with Candida albicans.
Applied and environmental microbiology [Epub ahead of print].
Streptococcus mutans strains expressing the collagen-binding protein Cnm are strongly associated with severe and recurrent dental caries, yet the mechanistic basis for their clinical enrichment alongside Candida albicans remains unclear. Here, we investigated whether Cnm contributes to early cross-kingdom interactions that promote dual-species biofilm development. Using purified proteins, we found that C. albicans binds robustly to Cnm at levels comparable to those of glucosyltransferase B (GtfB) and higher than those of other S. mutans adhesins tested. Preincubation of collagen with Cnm inhibited fungal binding, indicating that Cnm cannot simultaneously engage collagen and C. albicans, and suggesting competition for the same or adjacent binding regions. Cnm expression significantly enhanced coaggregation with C. albicans in both collagen-free and collagen-rich environments. In early attachment assays, Cnm increased S. mutans adherence to collagen-coated surfaces and promoted C. albicans recruitment on uncoated surfaces, consistent with ligand-dependent binding specificity. Pre-coaggregation in saliva further enhanced the ability of Cnm[+] S. mutans to attach to C. albicans. At 24 h, Cnm expression increased biomass and S. mutans CFUs exclusively on collagen-coated surfaces, regardless of sucrose availability. Together, these findings identify Cnm as a dual-binding adhesin that associates with either collagen or C. albicans, depending on environmental context, thereby accelerating coaggregation, early colonization, and biofilm maturation. This mechanism provides a biological explanation for the co-enrichment of Cbp[+] S. mutans and C. albicans seen in dental caries and highlights Cnm as a key mediator of cross-kingdom synergy in early biofilm formation.IMPORTANCEDental caries is a multifactorial and polymicrobial disease in which the consumption of fermentable carbohydrates favors acidogenic and aciduric microorganisms at the expense of beneficial commensal bacteria, creating a dysbiotic environment. Streptococcus mutans and Candida albicans establish a synergistic relationship that exacerbates dysbiosis, thereby promoting caries development and progression. The current paradigm of this cross-kingdom synergism centers on increased extracellular polysaccharide production and enhanced biofilm biomass in the presence of sucrose. Here, we show that the collagen-binding protein Cnm, produced by approximately 20% of S. mutans isolates, promotes interspecies co-aggregation with C. albicans, facilitating interspecies attachment and early biofilm formation. Our findings expand the current paradigm by demonstrating that Cnm recruits C. albicans to the developing biofilm. This interaction may play a crucial role in the stability and virulence of early biofilm communities, particularly under low-sucrose conditions.
Additional Links: PMID-42402036
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@article {pmid42402036,
year = {2026},
author = {Katrak, C and Bautista, L and Pepe, L and Fairman, J and Abranches, J},
title = {The Streptococcus mutans collagen-binding protein Cnm enhances early biofilm formation with Candida albicans.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0104626},
doi = {10.1128/aem.01046-26},
pmid = {42402036},
issn = {1098-5336},
abstract = {Streptococcus mutans strains expressing the collagen-binding protein Cnm are strongly associated with severe and recurrent dental caries, yet the mechanistic basis for their clinical enrichment alongside Candida albicans remains unclear. Here, we investigated whether Cnm contributes to early cross-kingdom interactions that promote dual-species biofilm development. Using purified proteins, we found that C. albicans binds robustly to Cnm at levels comparable to those of glucosyltransferase B (GtfB) and higher than those of other S. mutans adhesins tested. Preincubation of collagen with Cnm inhibited fungal binding, indicating that Cnm cannot simultaneously engage collagen and C. albicans, and suggesting competition for the same or adjacent binding regions. Cnm expression significantly enhanced coaggregation with C. albicans in both collagen-free and collagen-rich environments. In early attachment assays, Cnm increased S. mutans adherence to collagen-coated surfaces and promoted C. albicans recruitment on uncoated surfaces, consistent with ligand-dependent binding specificity. Pre-coaggregation in saliva further enhanced the ability of Cnm[+] S. mutans to attach to C. albicans. At 24 h, Cnm expression increased biomass and S. mutans CFUs exclusively on collagen-coated surfaces, regardless of sucrose availability. Together, these findings identify Cnm as a dual-binding adhesin that associates with either collagen or C. albicans, depending on environmental context, thereby accelerating coaggregation, early colonization, and biofilm maturation. This mechanism provides a biological explanation for the co-enrichment of Cbp[+] S. mutans and C. albicans seen in dental caries and highlights Cnm as a key mediator of cross-kingdom synergy in early biofilm formation.IMPORTANCEDental caries is a multifactorial and polymicrobial disease in which the consumption of fermentable carbohydrates favors acidogenic and aciduric microorganisms at the expense of beneficial commensal bacteria, creating a dysbiotic environment. Streptococcus mutans and Candida albicans establish a synergistic relationship that exacerbates dysbiosis, thereby promoting caries development and progression. The current paradigm of this cross-kingdom synergism centers on increased extracellular polysaccharide production and enhanced biofilm biomass in the presence of sucrose. Here, we show that the collagen-binding protein Cnm, produced by approximately 20% of S. mutans isolates, promotes interspecies co-aggregation with C. albicans, facilitating interspecies attachment and early biofilm formation. Our findings expand the current paradigm by demonstrating that Cnm recruits C. albicans to the developing biofilm. This interaction may play a crucial role in the stability and virulence of early biofilm communities, particularly under low-sucrose conditions.},
}
RevDate: 2026-07-05
Modeling Multiscale Architecture of Biofilm Extracellular Matrix and Its Role in Oxygen Transport.
Biotechnology and bioengineering [Epub ahead of print].
The extracellular polymeric substances (EPS) matrix of microbial biofilms exhibits a complex structural heterogeneity that profoundly influences mass transport and metabolic activity. Conventional biofilm models typically assume a homogeneous matrix, thereby neglecting the localized transport resistance introduced by the bacterial capsule, a distinct, low-diffusivity polysaccharide layer surrounding individual cells. In this theoretical study, we develop a multiscale "cell-capsule" continuum model that represents the capsule as a concentric shell enveloping each microbial cell core within the bulk EPS. Utilizing a one-dimensional reaction-diffusion framework coupled with a geometric characterization of capsule spacing and thickness, we quantify how microscale architecture modulates oxygen transport in developing biofilms. Model simulations demonstrate that incorporating a discrete capsular phase introduces a pronounced "resistance-in-series" effect, reducing local oxygen availability by up to 70% compared to conventional homogeneous models. Furthermore, our analysis indicates that capsule thickness and matrix compaction jointly control the effective diffusivity and oxygen effectiveness factor within the biofilm. These results provide critical mechanistic insights into how microscale organization governs macroscale biofilm function, offering a new framework for integrating structural heterogeneity into multiscale biofilm simulations.
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@article {pmid42402168,
year = {2026},
author = {Moorthy, RK and Casey, E},
title = {Modeling Multiscale Architecture of Biofilm Extracellular Matrix and Its Role in Oxygen Transport.},
journal = {Biotechnology and bioengineering},
volume = {},
number = {},
pages = {},
doi = {10.1002/bit.70295},
pmid = {42402168},
issn = {1097-0290},
support = {101052376/ERC_/European Research Council/International ; },
abstract = {The extracellular polymeric substances (EPS) matrix of microbial biofilms exhibits a complex structural heterogeneity that profoundly influences mass transport and metabolic activity. Conventional biofilm models typically assume a homogeneous matrix, thereby neglecting the localized transport resistance introduced by the bacterial capsule, a distinct, low-diffusivity polysaccharide layer surrounding individual cells. In this theoretical study, we develop a multiscale "cell-capsule" continuum model that represents the capsule as a concentric shell enveloping each microbial cell core within the bulk EPS. Utilizing a one-dimensional reaction-diffusion framework coupled with a geometric characterization of capsule spacing and thickness, we quantify how microscale architecture modulates oxygen transport in developing biofilms. Model simulations demonstrate that incorporating a discrete capsular phase introduces a pronounced "resistance-in-series" effect, reducing local oxygen availability by up to 70% compared to conventional homogeneous models. Furthermore, our analysis indicates that capsule thickness and matrix compaction jointly control the effective diffusivity and oxygen effectiveness factor within the biofilm. These results provide critical mechanistic insights into how microscale organization governs macroscale biofilm function, offering a new framework for integrating structural heterogeneity into multiscale biofilm simulations.},
}
RevDate: 2026-07-05
Phenacetin inhibited but acetaminophen stabilized partial nitrification/anammox system: Studies on microbial metabolism and resistance genes in biofilm and plastisphere.
Bioresource technology pii:S0960-8524(26)01399-4 [Epub ahead of print].
Partial nitrification (PN) inhibitors, such as phenacetin (PNCT) and acetaminophen (APAP), ensure a stable nitrite supply for anaerobic ammonium oxidation (anammox). But the unknown impact of inhibitors on anammox limit the application of inhibitors. In addition to the biofilm carriers used in biological nitrogen removal systems, microplastics (MPs) (a type of emerging contaminants) are the common substrate for microbial colonization, even enriched resistance genes (RGs). This research compared the effects of 0.5, 1 and 5 mg/L PNCT or APAP on partial nitrification-anammox (PN/A) biofilm and plastisphere. 1 mg/L PNCT inhibited the nitrogen removal functional bacteria (Nitrosomonas, Candidatus Kuenenia, Candidatus Brocadia and Nitrospira), resulting in the sharp deteriorated performance of PN/A system. 5 mg/L PNCT inhibited multiple metabolism pathways, resulting in the absence of electrons and energy supply of microorganisms. 0.5-1 mg/L APAP maintained the stable operation of PN/A system. Nitrospira abundances declined from 2.8% to 1.1% after 0.5 mg/L APAP exposure. But 5 mg/L APAP inhibited the abundance of amoA and the production of extracellular polymeric substances, which caused the slight fluctuation of PN/A performance. PN inhibitors did not cause the sharp increase of most RGs in biofilm and water. However, MPs exhibited the huge capacity of enriching RGs, which should be removed. This study proposed that 0.5 mg/L of APAP was suitable for the PN/A system to control dosage for practical application.
Additional Links: PMID-42402281
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@article {pmid42402281,
year = {2026},
author = {Zhang, J and Gao, J and Wang, H and Zhang, K and Lu, T},
title = {Phenacetin inhibited but acetaminophen stabilized partial nitrification/anammox system: Studies on microbial metabolism and resistance genes in biofilm and plastisphere.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {135317},
doi = {10.1016/j.biortech.2026.135317},
pmid = {42402281},
issn = {1873-2976},
abstract = {Partial nitrification (PN) inhibitors, such as phenacetin (PNCT) and acetaminophen (APAP), ensure a stable nitrite supply for anaerobic ammonium oxidation (anammox). But the unknown impact of inhibitors on anammox limit the application of inhibitors. In addition to the biofilm carriers used in biological nitrogen removal systems, microplastics (MPs) (a type of emerging contaminants) are the common substrate for microbial colonization, even enriched resistance genes (RGs). This research compared the effects of 0.5, 1 and 5 mg/L PNCT or APAP on partial nitrification-anammox (PN/A) biofilm and plastisphere. 1 mg/L PNCT inhibited the nitrogen removal functional bacteria (Nitrosomonas, Candidatus Kuenenia, Candidatus Brocadia and Nitrospira), resulting in the sharp deteriorated performance of PN/A system. 5 mg/L PNCT inhibited multiple metabolism pathways, resulting in the absence of electrons and energy supply of microorganisms. 0.5-1 mg/L APAP maintained the stable operation of PN/A system. Nitrospira abundances declined from 2.8% to 1.1% after 0.5 mg/L APAP exposure. But 5 mg/L APAP inhibited the abundance of amoA and the production of extracellular polymeric substances, which caused the slight fluctuation of PN/A performance. PN inhibitors did not cause the sharp increase of most RGs in biofilm and water. However, MPs exhibited the huge capacity of enriching RGs, which should be removed. This study proposed that 0.5 mg/L of APAP was suitable for the PN/A system to control dosage for practical application.},
}
RevDate: 2026-07-06
Mechanistic insights into the inhibition of biofilm formation and antibacterial action of endophytic Streptomyces strain KJ7TB2 isolated from the Indian Sundarbans Mangrove estuary.
Future microbiology [Epub ahead of print].
AIM: To explore the mechanism involved in the inhibition of biofilm formation and antibacterial action of endophytic Streptomyces sp. isolated from the Indian Sundarbans Mangrove Forest.
MATERIALS AND METHODS: In this study, Streptomyces sp. KJ7TB2 was isolated from the Indian Sundarbans. An ethyl acetate extract was subjected for GC-MS profiling. The mechanisms of antibacterial and antibiofilm action were also explored. In-silico molecular docking and dynamics simulation analyses were performed.
RESULTS: The GC-MS analysis of the extract revealed 14 distinct bioactive secondary metabolites. The extract exhibited potent MIC values of 250 μg/mL and 125 μg/mL against Escherichia coli MTCC 1195 and Pseudomonas aeruginosa ATCC 27853. Antibiofilm investigation further revealed inhibition of biofilm formation in both pathogens especially in E. coli MTCC 1195, likely by disrupting initial surface adhesion and exopolysaccharide synthesis. Also, the extract inhibited swarming motility, suggesting interference with flagella-driven motility and quorum sensing. The brine shrimp lethality assay confirmed a favorable safety profile, recording limited mortality (36.84% at 2×MIC over 24 h). In-silico molecular docking and dynamics simulation analyses exhibited robust affinity for two key biofilm-associated proteins, exhibiting significant binding energy (ΔG).
CONCLUSION: The study highlights Streptomyces sp. KJ7TB2 as a potential source for the discovery of safe, potent therapeutics.
Additional Links: PMID-42402899
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@article {pmid42402899,
year = {2026},
author = {Roy, S and Paul, P and Santra, R and Dolui, S and Pramanik, A and Halder, S and Karmakar, S and Biswas, P and Mazumder, K and Biswas, K},
title = {Mechanistic insights into the inhibition of biofilm formation and antibacterial action of endophytic Streptomyces strain KJ7TB2 isolated from the Indian Sundarbans Mangrove estuary.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {1-19},
doi = {10.1080/17460913.2026.2693388},
pmid = {42402899},
issn = {1746-0921},
abstract = {AIM: To explore the mechanism involved in the inhibition of biofilm formation and antibacterial action of endophytic Streptomyces sp. isolated from the Indian Sundarbans Mangrove Forest.
MATERIALS AND METHODS: In this study, Streptomyces sp. KJ7TB2 was isolated from the Indian Sundarbans. An ethyl acetate extract was subjected for GC-MS profiling. The mechanisms of antibacterial and antibiofilm action were also explored. In-silico molecular docking and dynamics simulation analyses were performed.
RESULTS: The GC-MS analysis of the extract revealed 14 distinct bioactive secondary metabolites. The extract exhibited potent MIC values of 250 μg/mL and 125 μg/mL against Escherichia coli MTCC 1195 and Pseudomonas aeruginosa ATCC 27853. Antibiofilm investigation further revealed inhibition of biofilm formation in both pathogens especially in E. coli MTCC 1195, likely by disrupting initial surface adhesion and exopolysaccharide synthesis. Also, the extract inhibited swarming motility, suggesting interference with flagella-driven motility and quorum sensing. The brine shrimp lethality assay confirmed a favorable safety profile, recording limited mortality (36.84% at 2×MIC over 24 h). In-silico molecular docking and dynamics simulation analyses exhibited robust affinity for two key biofilm-associated proteins, exhibiting significant binding energy (ΔG).
CONCLUSION: The study highlights Streptomyces sp. KJ7TB2 as a potential source for the discovery of safe, potent therapeutics.},
}
RevDate: 2026-07-06
CmpDate: 2026-07-06
Capnocytophaga ochracea sialidase drives its biofilm maturation and host cell interactions.
Frontiers in cellular and infection microbiology, 16:1841812.
INTRODUCTION: Capnocytophaga ochracea, an early colonizer of oral biofilms associated with gingivitis, plays an incompletely understood role in periodontal pathogenesis. While sialidases are established virulence factors in late-colonizing 'red-complex' pathogens, their function in early colonizers, such as C. ochracea, remains unknown.
METHODS: To address this knowledge gap, we identified and characterized Co-NanH, the sole sialidase of C. ochracea. We performed phylogenetic and structural analyses to compare it with known sialidases. Enzymatic assays were conducted using recombinant Co-NanH to determine its pH optimum, substrate specificity, and kinetic parameters. Furthermore, we utilized sialidase inhibitors (such as DANA) and generated a nanH genetic deletion mutant (ΔnanH) to assess the enzyme's role in planktonic growth, biofilm formation, and interactions with human gingival epithelial cells (adhesion and internalization).
RESULTS: Phylogenetic and structural analyses revealed that Co-NanH shares significant homology with a sialidase from Tannerella forsythia but possesses a distinct Sec/SPI signal peptide and a monomeric structure. Recombinant Co-NanH exhibited optimal activity at pH 5.5 and cleaved both α2,3- and α2,6-linked sialic acids, with kinetic parameters comparable to those of red-complex pathogen sialidases. Inhibitors like DANA potently suppressed its activity and reduced C. ochracea biofilm formation. Crucially, genetic deletion of nanH abolished sialidase activity without affecting planktonic growth. The ΔnanH mutant exhibited severely impaired biofilm formation, characterized by reduced biomass, thickness, and initial attachment. Furthermore, the mutant showed significantly reduced adhesion to and internalization by human gingival epithelial cells compared with wild-type and complemented strains.
DISCUSSION: These findings establish Co-NanH as a key mediator of C. ochracea in biofilm maturation and host cell interactions, revealing a functional parallel between early colonizers and classical periodontal pathogens. This work provides functional evidence that sialidase activity in an early colonizer contributes to oral dysbiosis by facilitating biofilm development and priming the host environment for disease progression.
Additional Links: PMID-42404778
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@article {pmid42404778,
year = {2026},
author = {He, J and Zhao, S and Ju, Y},
title = {Capnocytophaga ochracea sialidase drives its biofilm maturation and host cell interactions.},
journal = {Frontiers in cellular and infection microbiology},
volume = {16},
number = {},
pages = {1841812},
pmid = {42404778},
issn = {2235-2988},
mesh = {*Neuraminidase/metabolism/genetics/chemistry ; Humans ; *Biofilms/growth & development ; *Capnocytophaga/enzymology/genetics/physiology ; Epithelial Cells/microbiology ; Phylogeny ; *Host-Pathogen Interactions ; Hydrogen-Ion Concentration ; Bacterial Adhesion ; Substrate Specificity ; Virulence Factors/genetics/metabolism ; Gingiva/microbiology/cytology ; Gene Deletion ; },
abstract = {INTRODUCTION: Capnocytophaga ochracea, an early colonizer of oral biofilms associated with gingivitis, plays an incompletely understood role in periodontal pathogenesis. While sialidases are established virulence factors in late-colonizing 'red-complex' pathogens, their function in early colonizers, such as C. ochracea, remains unknown.
METHODS: To address this knowledge gap, we identified and characterized Co-NanH, the sole sialidase of C. ochracea. We performed phylogenetic and structural analyses to compare it with known sialidases. Enzymatic assays were conducted using recombinant Co-NanH to determine its pH optimum, substrate specificity, and kinetic parameters. Furthermore, we utilized sialidase inhibitors (such as DANA) and generated a nanH genetic deletion mutant (ΔnanH) to assess the enzyme's role in planktonic growth, biofilm formation, and interactions with human gingival epithelial cells (adhesion and internalization).
RESULTS: Phylogenetic and structural analyses revealed that Co-NanH shares significant homology with a sialidase from Tannerella forsythia but possesses a distinct Sec/SPI signal peptide and a monomeric structure. Recombinant Co-NanH exhibited optimal activity at pH 5.5 and cleaved both α2,3- and α2,6-linked sialic acids, with kinetic parameters comparable to those of red-complex pathogen sialidases. Inhibitors like DANA potently suppressed its activity and reduced C. ochracea biofilm formation. Crucially, genetic deletion of nanH abolished sialidase activity without affecting planktonic growth. The ΔnanH mutant exhibited severely impaired biofilm formation, characterized by reduced biomass, thickness, and initial attachment. Furthermore, the mutant showed significantly reduced adhesion to and internalization by human gingival epithelial cells compared with wild-type and complemented strains.
DISCUSSION: These findings establish Co-NanH as a key mediator of C. ochracea in biofilm maturation and host cell interactions, revealing a functional parallel between early colonizers and classical periodontal pathogens. This work provides functional evidence that sialidase activity in an early colonizer contributes to oral dysbiosis by facilitating biofilm development and priming the host environment for disease progression.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Neuraminidase/metabolism/genetics/chemistry
Humans
*Biofilms/growth & development
*Capnocytophaga/enzymology/genetics/physiology
Epithelial Cells/microbiology
Phylogeny
*Host-Pathogen Interactions
Hydrogen-Ion Concentration
Bacterial Adhesion
Substrate Specificity
Virulence Factors/genetics/metabolism
Gingiva/microbiology/cytology
Gene Deletion
RevDate: 2026-07-06
CmpDate: 2026-07-06
Funoran as a marine anti-biofilm polysaccharide for caries prevention: biological basis, current evidence, and translational challenges.
Frontiers in microbiology, 17:1859856.
Dental caries is a chronic biofilm-mediated disease that is caused by the interplay of plaque dysbiosis, persistent acid generation by cariogenic bacteria and host-associated environmental influences. Accordingly, current anti-caries measures increasingly focus on broader interventions targeting bacterial adhesion and colonization, biofilm formation, extracellular polysaccharide (EPS) production, and the local oral microecological equilibrium. Funoran, a sulfated polysaccharide derived from red algae, has become a promising natural marine bioactive, because it has desirable biocompatibility, interfacial activity, and potential anti-adhesive and antibiofilm properties. Current evidence suggests that funoran can reduce the adhesion of oral streptococci to tooth-relevant surfaces and may improve biofilm inhibition when combined with agents such as xylitol. Studies on structurally related algal polysaccharides further support the potential of marine polysaccharides in antibacterial, antibiofilm, anti-inflammatory, and oral delivery applications. Nevertheless, the development of funoran for caries prevention is still constrained by limited direct evidence, unclear mechanisms, non-standardized evaluation systems, and insufficient clinical research. Future studies should emphasize structural characterization, mechanistic investigation, standardized biological evaluation, and local delivery design to accelerate its translation into precision caries prevention.
Additional Links: PMID-42404791
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@article {pmid42404791,
year = {2026},
author = {Guo, F and Lu, L and Song, L and Jiao, Y and Sun, D},
title = {Funoran as a marine anti-biofilm polysaccharide for caries prevention: biological basis, current evidence, and translational challenges.},
journal = {Frontiers in microbiology},
volume = {17},
number = {},
pages = {1859856},
pmid = {42404791},
issn = {1664-302X},
abstract = {Dental caries is a chronic biofilm-mediated disease that is caused by the interplay of plaque dysbiosis, persistent acid generation by cariogenic bacteria and host-associated environmental influences. Accordingly, current anti-caries measures increasingly focus on broader interventions targeting bacterial adhesion and colonization, biofilm formation, extracellular polysaccharide (EPS) production, and the local oral microecological equilibrium. Funoran, a sulfated polysaccharide derived from red algae, has become a promising natural marine bioactive, because it has desirable biocompatibility, interfacial activity, and potential anti-adhesive and antibiofilm properties. Current evidence suggests that funoran can reduce the adhesion of oral streptococci to tooth-relevant surfaces and may improve biofilm inhibition when combined with agents such as xylitol. Studies on structurally related algal polysaccharides further support the potential of marine polysaccharides in antibacterial, antibiofilm, anti-inflammatory, and oral delivery applications. Nevertheless, the development of funoran for caries prevention is still constrained by limited direct evidence, unclear mechanisms, non-standardized evaluation systems, and insufficient clinical research. Future studies should emphasize structural characterization, mechanistic investigation, standardized biological evaluation, and local delivery design to accelerate its translation into precision caries prevention.},
}
RevDate: 2026-07-06
CmpDate: 2026-07-06
Superelastic Ti-Zr-Nb-Sn Thin Films Fabricated by Magnetron Sputtering: Biocompatibility and Bacterial Biofilm Formation Assessment for Orthopedic Applications.
Journal of biomedical materials research. Part A, 114(7):e70119.
Nickel-titanium (NiTi) alloys are widely used in orthopedics because of their excellent mechanical properties; however, hypersensitivity remains a concern because of Ni ion release during long-term implantation. To address this issue, we manufactured Ti-Zr-xNb-Sn thin films (x = 10, 15, 17, 20 at.%) using magnetron-sputtering, intended as coatings for NiTi devices. Given the superelasticity of Ti-Zr-Nb-Sn alloys, these coatings are expected to not only suppress the Ni ion release from the NiTi substrate but also reduce the formation of cracks in the coating by accommodating the substrate's deformation. The biocompatibility of the coatings was evaluated both in vitro and in vivo, as well as the potential risk of forming bacterial biofilms. Ti-Zr-xNb-Sn coatings (x = 15, 17 at.%) promoted pre-osteoblast differentiation compared to uncoated NiTi, without increasing the risk of biofilm formation by Staphylococcus epidermidis. The coated NiTi wires were implanted subcutaneously in mice for 28 days, and no strong rejection reaction was observed compared to uncoated NiTi. Additionally, the coatings showed superior corrosion resistance, indicating improved long-term stability. The deposition angle during sputtering influenced cell differentiation, suggesting that both chemical composition and surface morphology contribute to osteogenic responses. Overall, Ti-Zr-Nb-Sn coatings are a promising surface modification strategy for NiTi orthopedic implants.
Additional Links: PMID-42405698
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PubMed:
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@article {pmid42405698,
year = {2026},
author = {Chigama, H and Choquet, T and Vigneron, P and Gordin, D and Michel, A and Chelariu, R and Cimpoeșu, R and Fayeulle, A and Grosset, JF and Pereira, U and Gloriant, T and Abadias, G and Fillon, A and Vayssade, M},
title = {Superelastic Ti-Zr-Nb-Sn Thin Films Fabricated by Magnetron Sputtering: Biocompatibility and Bacterial Biofilm Formation Assessment for Orthopedic Applications.},
journal = {Journal of biomedical materials research. Part A},
volume = {114},
number = {7},
pages = {e70119},
doi = {10.1002/jbm.a.70119},
pmid = {42405698},
issn = {1552-4965},
support = {18-CE08-0017 Super-Rev//Agence Nationale de la Recherche/ ; },
mesh = {Animals ; *Biofilms/growth & development/drug effects ; Mice ; *Titanium/chemistry/pharmacology ; *Staphylococcus epidermidis/physiology/drug effects ; Zirconium/chemistry/pharmacology ; Osteoblasts/cytology/drug effects ; *Materials Testing ; *Coated Materials, Biocompatible/chemistry/pharmacology ; *Alloys/chemistry/pharmacology ; Niobium/chemistry/pharmacology ; Elasticity ; Corrosion ; },
abstract = {Nickel-titanium (NiTi) alloys are widely used in orthopedics because of their excellent mechanical properties; however, hypersensitivity remains a concern because of Ni ion release during long-term implantation. To address this issue, we manufactured Ti-Zr-xNb-Sn thin films (x = 10, 15, 17, 20 at.%) using magnetron-sputtering, intended as coatings for NiTi devices. Given the superelasticity of Ti-Zr-Nb-Sn alloys, these coatings are expected to not only suppress the Ni ion release from the NiTi substrate but also reduce the formation of cracks in the coating by accommodating the substrate's deformation. The biocompatibility of the coatings was evaluated both in vitro and in vivo, as well as the potential risk of forming bacterial biofilms. Ti-Zr-xNb-Sn coatings (x = 15, 17 at.%) promoted pre-osteoblast differentiation compared to uncoated NiTi, without increasing the risk of biofilm formation by Staphylococcus epidermidis. The coated NiTi wires were implanted subcutaneously in mice for 28 days, and no strong rejection reaction was observed compared to uncoated NiTi. Additionally, the coatings showed superior corrosion resistance, indicating improved long-term stability. The deposition angle during sputtering influenced cell differentiation, suggesting that both chemical composition and surface morphology contribute to osteogenic responses. Overall, Ti-Zr-Nb-Sn coatings are a promising surface modification strategy for NiTi orthopedic implants.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
Animals
*Biofilms/growth & development/drug effects
Mice
*Titanium/chemistry/pharmacology
*Staphylococcus epidermidis/physiology/drug effects
Zirconium/chemistry/pharmacology
Osteoblasts/cytology/drug effects
*Materials Testing
*Coated Materials, Biocompatible/chemistry/pharmacology
*Alloys/chemistry/pharmacology
Niobium/chemistry/pharmacology
Elasticity
Corrosion
RevDate: 2026-07-03
CmpDate: 2026-07-03
From adhesion to gene regulation: tea tree essential oil suppresses Uropathogenic Escherichia coli colonization while triggering csgA-mediated biofilm stress paradox.
Molecular biology reports, 53(1):.
BACKGROUND AND OBJECTIVES: Uropathogenic E.coli (UPEC) are major causative agents of urinary tract infection (UTIs), they often possess strong biofilm-forming abilities, and capable of resisting many antibiotics, making catheter associated UTIs (CAUTIs) difficult to treat. Essential oils such as tea tree oil (TTO) have emerged as natural alternatives to antibiotics. This study aimed to evaluate the antibacterial, adhesion, and biofilm-forming efficacy of TTO against UPEC, while analyzing its effect on the gene expression of csgA gene and determining its cytotoxicity.
METHODS: Four UPEC isolates collected from different UTIs patients from Baghdad Province. The Antibacterial activity of TTO evaluated using agar wells diffusion assay and micro dilution using resazurin. Anti-adhesion and anti-biofilm were assessed using silicon Foley catheters. The csgA encode to curli fibers determined using polymerase chain reaction (PCR) and gene expression measured using qPCR. Cytotoxicity of TTO measured against renal carcinoma (A498) and normal fibroblast (HdFn) cell lines via MTT assay.
RESULTS: TTO inhibited UPEC with inhibition zone diameter of 12-25 mm (p < 0.0001) and MIC value was 0.25%. In Foley catheter model, the concentrated TTO reduced adhesion and biofilm formation (p < 0.0001). csgA harbored within all subjected isolates. Real time quantitative PCR (RT-qPCR) revealed significant (p < 0.0001) upregulation within susceptible isolates (2.2) fold change. Cytotoxicity via MTT assay reveled selective activity of TTO on (A498, IC50= 265.8 µg/mL) over (HdFn, IC50 = 852.5 µg/mL; p < 0.0001).
CONCLUSION: TTO demonstrated potential antibacterial, anti-adhesion and anti-biofilm activity against UPEC along with modulations of csgA gene expression and selective cytotoxicity.
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@article {pmid42397613,
year = {2026},
author = {Al-Zaidi, OSSH and Zwain, LA and Mahmoud, EA},
title = {From adhesion to gene regulation: tea tree essential oil suppresses Uropathogenic Escherichia coli colonization while triggering csgA-mediated biofilm stress paradox.},
journal = {Molecular biology reports},
volume = {53},
number = {1},
pages = {},
pmid = {42397613},
issn = {1573-4978},
mesh = {*Biofilms/drug effects ; *Uropathogenic Escherichia coli/drug effects/genetics ; Humans ; *Tea Tree Oil/pharmacology ; Bacterial Adhesion/drug effects ; Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; Urinary Tract Infections/microbiology/drug therapy ; Escherichia coli Proteins/genetics/metabolism ; Gene Expression Regulation, Bacterial/drug effects ; Escherichia coli Infections/microbiology/drug therapy ; Oils, Volatile/pharmacology ; },
abstract = {BACKGROUND AND OBJECTIVES: Uropathogenic E.coli (UPEC) are major causative agents of urinary tract infection (UTIs), they often possess strong biofilm-forming abilities, and capable of resisting many antibiotics, making catheter associated UTIs (CAUTIs) difficult to treat. Essential oils such as tea tree oil (TTO) have emerged as natural alternatives to antibiotics. This study aimed to evaluate the antibacterial, adhesion, and biofilm-forming efficacy of TTO against UPEC, while analyzing its effect on the gene expression of csgA gene and determining its cytotoxicity.
METHODS: Four UPEC isolates collected from different UTIs patients from Baghdad Province. The Antibacterial activity of TTO evaluated using agar wells diffusion assay and micro dilution using resazurin. Anti-adhesion and anti-biofilm were assessed using silicon Foley catheters. The csgA encode to curli fibers determined using polymerase chain reaction (PCR) and gene expression measured using qPCR. Cytotoxicity of TTO measured against renal carcinoma (A498) and normal fibroblast (HdFn) cell lines via MTT assay.
RESULTS: TTO inhibited UPEC with inhibition zone diameter of 12-25 mm (p < 0.0001) and MIC value was 0.25%. In Foley catheter model, the concentrated TTO reduced adhesion and biofilm formation (p < 0.0001). csgA harbored within all subjected isolates. Real time quantitative PCR (RT-qPCR) revealed significant (p < 0.0001) upregulation within susceptible isolates (2.2) fold change. Cytotoxicity via MTT assay reveled selective activity of TTO on (A498, IC50= 265.8 µg/mL) over (HdFn, IC50 = 852.5 µg/mL; p < 0.0001).
CONCLUSION: TTO demonstrated potential antibacterial, anti-adhesion and anti-biofilm activity against UPEC along with modulations of csgA gene expression and selective cytotoxicity.},
}
MeSH Terms:
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*Biofilms/drug effects
*Uropathogenic Escherichia coli/drug effects/genetics
Humans
*Tea Tree Oil/pharmacology
Bacterial Adhesion/drug effects
Anti-Bacterial Agents/pharmacology
Microbial Sensitivity Tests
Urinary Tract Infections/microbiology/drug therapy
Escherichia coli Proteins/genetics/metabolism
Gene Expression Regulation, Bacterial/drug effects
Escherichia coli Infections/microbiology/drug therapy
Oils, Volatile/pharmacology
RevDate: 2026-07-03
Distinct contributions of the Agr and LuxS quorum-sensing systems to stress tolerance, biofilm formation, and persistence of Staphylococcus aureus in dairy-processing environments.
Journal of dairy science pii:S0022-0302(26)03072-9 [Epub ahead of print].
Staphylococcus aureus (S. aureus) is a major foodborne pathogen frequently associated with the contamination of milk and dairy products. It persists in dairy-processing environments by tolerating diverse environmental stresses and forming biofilms on equipment surfaces. While quorum-sensing (QS) systems are known to regulate bacterial physiology, their specific contributions to stress adaptation in the context of dairy processing remain poorly understood. In this study, Δagr, ΔluxS, and ΔagrΔluxS mutants were constructed in a methicillin-resistant S. aureus (MRSA) background to evaluate contributions of the Agr and LuxS QS systems to survive under food-associated stress conditions. Deletion of agr significantly reduced survival under oxidative, acid, heat, and desiccation stresses, while enhancing biofilm formation. In contrast, luxS deletion selectively impaired tolerance to heat and desiccation without affecting biofilm formation. Additionally, the ΔagrΔluxS double mutant largely phenocopied the Δagr mutant, exhibiting a further decrease in heat and desiccation tolerance, suggesting an additive effect between the 2 systems. Furthermore, integrated transcriptomic analysis and RT-qPCR validation not only confirmed the phenotypic observations at the genetic level but also revealed Agr-dominant regulation of stress-response pathways, including molecular chaperones (clpC, clpB, dnaK, groESL), acid-resistance genes (ureABCD), and desiccation-associated genes, whereas LuxS exhibited a more selective effect on heat- and desiccation-related responses. In conclusion, these findings identify Agr as a central regulator of stress adaptation in S. aureus and suggest that targeting QS systems may be a viable strategy to reduce bacterial persistence in dairy production and processing environments.
Additional Links: PMID-42398725
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PubMed:
Citation:
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@article {pmid42398725,
year = {2026},
author = {Wang, H and Ma, K and Shen, J and Zhang, B and Zhang, S and Wang, X and Yang, X and Xue, T},
title = {Distinct contributions of the Agr and LuxS quorum-sensing systems to stress tolerance, biofilm formation, and persistence of Staphylococcus aureus in dairy-processing environments.},
journal = {Journal of dairy science},
volume = {},
number = {},
pages = {},
doi = {10.3168/jds.2026-28632},
pmid = {42398725},
issn = {1525-3198},
abstract = {Staphylococcus aureus (S. aureus) is a major foodborne pathogen frequently associated with the contamination of milk and dairy products. It persists in dairy-processing environments by tolerating diverse environmental stresses and forming biofilms on equipment surfaces. While quorum-sensing (QS) systems are known to regulate bacterial physiology, their specific contributions to stress adaptation in the context of dairy processing remain poorly understood. In this study, Δagr, ΔluxS, and ΔagrΔluxS mutants were constructed in a methicillin-resistant S. aureus (MRSA) background to evaluate contributions of the Agr and LuxS QS systems to survive under food-associated stress conditions. Deletion of agr significantly reduced survival under oxidative, acid, heat, and desiccation stresses, while enhancing biofilm formation. In contrast, luxS deletion selectively impaired tolerance to heat and desiccation without affecting biofilm formation. Additionally, the ΔagrΔluxS double mutant largely phenocopied the Δagr mutant, exhibiting a further decrease in heat and desiccation tolerance, suggesting an additive effect between the 2 systems. Furthermore, integrated transcriptomic analysis and RT-qPCR validation not only confirmed the phenotypic observations at the genetic level but also revealed Agr-dominant regulation of stress-response pathways, including molecular chaperones (clpC, clpB, dnaK, groESL), acid-resistance genes (ureABCD), and desiccation-associated genes, whereas LuxS exhibited a more selective effect on heat- and desiccation-related responses. In conclusion, these findings identify Agr as a central regulator of stress adaptation in S. aureus and suggest that targeting QS systems may be a viable strategy to reduce bacterial persistence in dairy production and processing environments.},
}
RevDate: 2026-07-04
New insights into how sludge wasting timing steers microbial community assembly and performance in hybrid PAO biofilm reactors.
Environmental research pii:S0013-9351(26)01455-6 [Epub ahead of print].
A limited understanding of how suspended sludge wasting timing (SWT) steers microbial community assembly and biofilm performance has hampered the establishment of ecological connections between operational parameters and system function in phosphate-accumulating organism (PAO) enriched biofilm reactors. Four sequencing batch biofilm reactors (SBBRs) were operated with distinct wasting timings (20, 30, 50, and 60 days). The reactor with a 30-day wasting timing achieved the earliest growth inflection point (day 27), the fastest nitrification recovery (80% within 7-10 days post-discharge), and the highest PAO abundance (8.97% by day 73). Early discharge (20 days) reduced initial attached biomass and prolonged subsequent development, while discharging too late (≥50 days) delayed the inflection point by 6-11 days and extended nitrification recovery to 20-26 days. Stochastic processes (ecological drift) dominated community assembly under extended SWT, whereas deterministic processes (heterogeneous selection) progressively dominated under the optimal 30-day regime. This deterministic shift fostered a larger, more modular co-occurrence network and more complex interspecies interactions. Keystone functional guilds, including PAOs (Thiothrix, Azospira, Dechloromonas, total abundance 8.97%), AOB (Ellin6067, norank_f_NS9_marine_group), NOB (Nitrospira), and GAO (Candidatus Competibacter), were enriched to higher levels. The synergistic cooperation among these functional bacteria facilitated simultaneous nitrogen removal and phosphorus enrichment. These results demonstrate that SWT acts as a deterministic filter, which is strongly associated with the transition of community assembly from stochastic colonization to function-oriented selection, providing insights for startup and microbial management of hybrid biofilm reactors.
Additional Links: PMID-42401289
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PubMed:
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@article {pmid42401289,
year = {2026},
author = {Bi, Z and Zhu, X and Pan, Y},
title = {New insights into how sludge wasting timing steers microbial community assembly and performance in hybrid PAO biofilm reactors.},
journal = {Environmental research},
volume = {},
number = {},
pages = {125124},
doi = {10.1016/j.envres.2026.125124},
pmid = {42401289},
issn = {1096-0953},
abstract = {A limited understanding of how suspended sludge wasting timing (SWT) steers microbial community assembly and biofilm performance has hampered the establishment of ecological connections between operational parameters and system function in phosphate-accumulating organism (PAO) enriched biofilm reactors. Four sequencing batch biofilm reactors (SBBRs) were operated with distinct wasting timings (20, 30, 50, and 60 days). The reactor with a 30-day wasting timing achieved the earliest growth inflection point (day 27), the fastest nitrification recovery (80% within 7-10 days post-discharge), and the highest PAO abundance (8.97% by day 73). Early discharge (20 days) reduced initial attached biomass and prolonged subsequent development, while discharging too late (≥50 days) delayed the inflection point by 6-11 days and extended nitrification recovery to 20-26 days. Stochastic processes (ecological drift) dominated community assembly under extended SWT, whereas deterministic processes (heterogeneous selection) progressively dominated under the optimal 30-day regime. This deterministic shift fostered a larger, more modular co-occurrence network and more complex interspecies interactions. Keystone functional guilds, including PAOs (Thiothrix, Azospira, Dechloromonas, total abundance 8.97%), AOB (Ellin6067, norank_f_NS9_marine_group), NOB (Nitrospira), and GAO (Candidatus Competibacter), were enriched to higher levels. The synergistic cooperation among these functional bacteria facilitated simultaneous nitrogen removal and phosphorus enrichment. These results demonstrate that SWT acts as a deterministic filter, which is strongly associated with the transition of community assembly from stochastic colonization to function-oriented selection, providing insights for startup and microbial management of hybrid biofilm reactors.},
}
RevDate: 2026-07-03
CmpDate: 2026-07-03
Low concentrations of tetrasodium EDTA cause significant killing of biofilm-associated Pseudomonas aeruginosa in high-validity models of chronic wound and cystic fibrosis lung infections - but not in a model of endotracheal tube colonization.
Access microbiology, 8(7):.
Pseudomonas aeruginosa is a pathogen notorious for its antimicrobial resistance and is currently classified as a high-priority pathogen for which new drugs are needed. Tetrasodium EDTA (tEDTA) is one of the new antimicrobial compounds that have been shown to have good antibacterial and antibiofilm efficacy against P. aeruginosa. Due to the diversity and highly drug-tolerant nature of P. aeruginosa biofilms in different infection environments, it is important to carry out pre-clinical testing of new antibiofilm agents against this pathogen in media and models that accurately mimic diverse infection environments. In this study, we used different high-validity media and biofilm models that mimic chronic wounds, endotracheal tubes and cystic fibrosis lung infections to assess the efficacy of tEDTA against P. aeruginosa biofilms. We report that different infection environments influence the susceptibility of both planktonic and biofilm forms of P. aeruginosa to tEDTA. The highest tolerance to tEDTA was observed in the media and biofilm model that mimics the endotracheal tube environment. In conclusion, we show that although different infection environments influence the efficacy of tEDTA against P. aeruginosa biofilms, it has good potential for use as an alternative antimicrobial in treating P. aeruginosa-associated biofilm infections.
Additional Links: PMID-42396178
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Citation:
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@article {pmid42396178,
year = {2026},
author = {Orababa, OQ and Cornbill, C and Kade, A and Reddy, N and Gulati, R and Harrison, F},
title = {Low concentrations of tetrasodium EDTA cause significant killing of biofilm-associated Pseudomonas aeruginosa in high-validity models of chronic wound and cystic fibrosis lung infections - but not in a model of endotracheal tube colonization.},
journal = {Access microbiology},
volume = {8},
number = {7},
pages = {},
pmid = {42396178},
issn = {2516-8290},
abstract = {Pseudomonas aeruginosa is a pathogen notorious for its antimicrobial resistance and is currently classified as a high-priority pathogen for which new drugs are needed. Tetrasodium EDTA (tEDTA) is one of the new antimicrobial compounds that have been shown to have good antibacterial and antibiofilm efficacy against P. aeruginosa. Due to the diversity and highly drug-tolerant nature of P. aeruginosa biofilms in different infection environments, it is important to carry out pre-clinical testing of new antibiofilm agents against this pathogen in media and models that accurately mimic diverse infection environments. In this study, we used different high-validity media and biofilm models that mimic chronic wounds, endotracheal tubes and cystic fibrosis lung infections to assess the efficacy of tEDTA against P. aeruginosa biofilms. We report that different infection environments influence the susceptibility of both planktonic and biofilm forms of P. aeruginosa to tEDTA. The highest tolerance to tEDTA was observed in the media and biofilm model that mimics the endotracheal tube environment. In conclusion, we show that although different infection environments influence the efficacy of tEDTA against P. aeruginosa biofilms, it has good potential for use as an alternative antimicrobial in treating P. aeruginosa-associated biofilm infections.},
}
RevDate: 2026-07-03
Biomimetic Nanoplatform for Dual Target Nano-Metabolic Therapy in Diabetes-Associated Biofilm Infections.
Advanced science (Weinheim, Baden-Wurttemberg, Germany) [Epub ahead of print].
Metabolism alterations significantly influence the behavior of both bacteria and immune cells in the microenvironment of diabetes-associated biofilm infections, ultimately determining the outcome of infections. Here, we propose a dual-target nano-metabolic therapy based on a biomimetic nanoplatform to combat these infections. The nanoplatform, coated with cellular membranes from pre-infected macrophages and loaded with glucose oxidase (GOx) and L-arginine (Arg), facilitates targeted drug delivery. Nitric oxide (NO), generated in situ through the catalytic cascade reaction of GOx and Arg, acts as a dual-target metabolic regulator. It disrupts bacterial carbon and nitrogen metabolism, particularly the tricarboxylic acid (TCA) cycle and amino acid metabolism, effectively eliminating biofilms. Simultaneously, NO modulates macrophage metabolism, shifting it from oxidative phosphorylation to aerobic glycolysis by suppressing TCA cycle enzymes and electron transport chain complexes, while preserving mitochondrial integrity. This energy metabolism transition reverses macrophage immunosuppression, enhancing their phagocytic and invasive functions to promote infection clearance. Experiments with multiple clinical bacterial strains and various diabetic infection models highlight the therapeutic potential of combining metabolism interference with immune modulation, offering new insights for the treatment of diabetes-associated biofilm infections.
Additional Links: PMID-42397073
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PubMed:
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@article {pmid42397073,
year = {2026},
author = {Li, M and Li, Y and Yan, J and Wang, C and Yu, J and Jiang, F and Wang, B and Yang, Y and Ding, D and Tang, J and Han, P and Song, B and Guo, G and Shen, H},
title = {Biomimetic Nanoplatform for Dual Target Nano-Metabolic Therapy in Diabetes-Associated Biofilm Infections.},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
volume = {},
number = {},
pages = {e76411},
doi = {10.1002/advs.76411},
pmid = {42397073},
issn = {2198-3844},
support = {82472465//National Natural Science Foundation of China/ ; 82202727//National Natural Science Foundation of China/ ; 82272511//National Natural Science Foundation of China/ ; ynyq202301//Excellent Talent Cultivation Project of Shanghai Sixth People's Hospital/ ; },
abstract = {Metabolism alterations significantly influence the behavior of both bacteria and immune cells in the microenvironment of diabetes-associated biofilm infections, ultimately determining the outcome of infections. Here, we propose a dual-target nano-metabolic therapy based on a biomimetic nanoplatform to combat these infections. The nanoplatform, coated with cellular membranes from pre-infected macrophages and loaded with glucose oxidase (GOx) and L-arginine (Arg), facilitates targeted drug delivery. Nitric oxide (NO), generated in situ through the catalytic cascade reaction of GOx and Arg, acts as a dual-target metabolic regulator. It disrupts bacterial carbon and nitrogen metabolism, particularly the tricarboxylic acid (TCA) cycle and amino acid metabolism, effectively eliminating biofilms. Simultaneously, NO modulates macrophage metabolism, shifting it from oxidative phosphorylation to aerobic glycolysis by suppressing TCA cycle enzymes and electron transport chain complexes, while preserving mitochondrial integrity. This energy metabolism transition reverses macrophage immunosuppression, enhancing their phagocytic and invasive functions to promote infection clearance. Experiments with multiple clinical bacterial strains and various diabetic infection models highlight the therapeutic potential of combining metabolism interference with immune modulation, offering new insights for the treatment of diabetes-associated biofilm infections.},
}
RevDate: 2026-07-02
Natural deep eutectic solvents as environmentally compatible agents for biofilm inhibition and disruption.
Biofouling [Epub ahead of print].
Natural deep eutectic solvents (NADES) have recently emerged as promising 'green' antibiofilm agents due to their ability to solubilize biological macromolecules. In this study, three chemically distinct NADES formulations were evaluated against Pseudomonas fluorescens WCS365 and Staphylococcus epidermidis ATCC 35984. The tested formulations choline chloride-lactic acid (CCLA), choline chloride-urea (CCU), and choline chloride-xylitol (CCX) were assessed for their effects on planktonic growth, biofilm formation, and mature biofilms. All NADES showed moderate inhibition of planktonic growth, while biofilm formation was significantly reduced in a formulation- and species-dependent manner, with CCLA displaying the strongest activity. Treatment of pre-formed 24 h biofilms resulted in partial but significant biomass reduction, reaching up to ∼69% for P. fluorescens and ∼51% for S. epidermidis. Confocal microscopy confirmed pronounced structural disruption of mature biofilms following NADES exposure, particularly for CCLA. These findings highlight the potential of organic acid-based NADES as biocides, which are more environmentally compatible than conventional biocides.
Additional Links: PMID-42389780
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PubMed:
Citation:
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@article {pmid42389780,
year = {2026},
author = {Naguib, M and Chakraborty, D and Dunne, C and Hiebner, D and Jones, R and Casey, E},
title = {Natural deep eutectic solvents as environmentally compatible agents for biofilm inhibition and disruption.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-18},
doi = {10.1080/08927014.2026.2694439},
pmid = {42389780},
issn = {1029-2454},
abstract = {Natural deep eutectic solvents (NADES) have recently emerged as promising 'green' antibiofilm agents due to their ability to solubilize biological macromolecules. In this study, three chemically distinct NADES formulations were evaluated against Pseudomonas fluorescens WCS365 and Staphylococcus epidermidis ATCC 35984. The tested formulations choline chloride-lactic acid (CCLA), choline chloride-urea (CCU), and choline chloride-xylitol (CCX) were assessed for their effects on planktonic growth, biofilm formation, and mature biofilms. All NADES showed moderate inhibition of planktonic growth, while biofilm formation was significantly reduced in a formulation- and species-dependent manner, with CCLA displaying the strongest activity. Treatment of pre-formed 24 h biofilms resulted in partial but significant biomass reduction, reaching up to ∼69% for P. fluorescens and ∼51% for S. epidermidis. Confocal microscopy confirmed pronounced structural disruption of mature biofilms following NADES exposure, particularly for CCLA. These findings highlight the potential of organic acid-based NADES as biocides, which are more environmentally compatible than conventional biocides.},
}
RevDate: 2026-07-02
CmpDate: 2026-07-02
Identifiability, Sensitivity, and Genetic Algorithms in Bacterial Biofilm Selection Models.
Bulletin of mathematical biology, 88(7):.
Bacteria often develop distinct phenotypes to adapt to environmental stress. In particular, they can produce biofilms, dense communities of bacteria that live in a complex extracellular matrix. While previous studies have investigated how bacterial biofilms are regulated under laboratory conditions, they have not considered (1) the data requirements necessary to estimate model parameters and (2) how bacteria respond to recurring stressors in their natural habitats. To address (1), we adapted a mechanistic population model to explore the dynamics of biofilm formation in the presence of predator stress, using synthetic data. We used a Maximum Likelihood Estimation framework to measure crucial parameters underpinning the biofilm formation dynamics. We used genetic algorithms to propose an optimal data collection schedule that minimised parameter identifiability confidence interval widths. Our sensitivity analysis revealed that, within the explored regimes, we could simplify the binding dynamics and eliminate biofilm detachment. To address (2), we proposed a structured version of our model to capture the long-term behaviour and evolutionary selection. In our extended model, the subpopulations feature different maximal rates of biofilm formation. We compared the selection under different predator types and amounts and identified key parameters that affected the speed of selection via sensitivity analysis.
Additional Links: PMID-42390640
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@article {pmid42390640,
year = {2026},
author = {Williams, S and Cheam, D and Nishiguchi, MK and Sindi, SS and Khatri, S and Rutter, EM},
title = {Identifiability, Sensitivity, and Genetic Algorithms in Bacterial Biofilm Selection Models.},
journal = {Bulletin of mathematical biology},
volume = {88},
number = {7},
pages = {},
pmid = {42390640},
issn = {1522-9602},
support = {DBI 2214038//National Science Foundation/ ; },
mesh = {*Biofilms/growth & development ; *Models, Biological ; Mathematical Concepts ; Genetic Algorithms ; Computer Simulation ; *Bacterial Physiological Phenomena ; Likelihood Functions ; Biological Evolution ; },
abstract = {Bacteria often develop distinct phenotypes to adapt to environmental stress. In particular, they can produce biofilms, dense communities of bacteria that live in a complex extracellular matrix. While previous studies have investigated how bacterial biofilms are regulated under laboratory conditions, they have not considered (1) the data requirements necessary to estimate model parameters and (2) how bacteria respond to recurring stressors in their natural habitats. To address (1), we adapted a mechanistic population model to explore the dynamics of biofilm formation in the presence of predator stress, using synthetic data. We used a Maximum Likelihood Estimation framework to measure crucial parameters underpinning the biofilm formation dynamics. We used genetic algorithms to propose an optimal data collection schedule that minimised parameter identifiability confidence interval widths. Our sensitivity analysis revealed that, within the explored regimes, we could simplify the binding dynamics and eliminate biofilm detachment. To address (2), we proposed a structured version of our model to capture the long-term behaviour and evolutionary selection. In our extended model, the subpopulations feature different maximal rates of biofilm formation. We compared the selection under different predator types and amounts and identified key parameters that affected the speed of selection via sensitivity analysis.},
}
MeSH Terms:
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*Biofilms/growth & development
*Models, Biological
Mathematical Concepts
Genetic Algorithms
Computer Simulation
*Bacterial Physiological Phenomena
Likelihood Functions
Biological Evolution
RevDate: 2026-07-02
K38 Succinylation of CsrA Regulates Biofilm Formation in Pseudomonas fluorescens PF08 by Modulating c-di-GMP Levels.
Journal of agricultural and food chemistry [Epub ahead of print].
Pseudomonas fluorescens PF08 is a significant food spoilage organism belonging to a species widely utilized for agricultural biocontrol, yet the post-translational regulation of its biofilm formation remains poorly understood. This work explored the role of lysine succinylation (Ksucc) in regulating CsrA activity, a global post-transcriptional regulator. NanoHPLC-MS/MS identified Lys38 (K38), a highly conserved residue within the CsrA RNA-binding interface, as a functional succinylation site. Site-directed mutagenesis revealed that K38 succinylation significantly inhibits biofilm formation by reducing c-di-GMP levels, exopolysaccharide production, and surface hydrophobicity, while enhancing flagellar-mediated motility. Colonization assays on foods, contact surfaces, and the rhizosphere confirmed that CsrA succinylation restricts biofilm formation across diverse ecological niches. These results identify K38 succinylation of CsrA as a regulatory modification that modulates the transition between motile and sessile lifestyles in P. fluorescens PF08. These findings expand the understanding of post-translational control of biofilm formation in this ecologically versatile bacterium relevant to food spoilage and agricultural environments.
Additional Links: PMID-42391643
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PubMed:
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@article {pmid42391643,
year = {2026},
author = {Wang, F and Yang, R and Chen, Z and Tan, R and Chen, J and Zhu, R and Wang, Y},
title = {K38 Succinylation of CsrA Regulates Biofilm Formation in Pseudomonas fluorescens PF08 by Modulating c-di-GMP Levels.},
journal = {Journal of agricultural and food chemistry},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.jafc.6c02003},
pmid = {42391643},
issn = {1520-5118},
abstract = {Pseudomonas fluorescens PF08 is a significant food spoilage organism belonging to a species widely utilized for agricultural biocontrol, yet the post-translational regulation of its biofilm formation remains poorly understood. This work explored the role of lysine succinylation (Ksucc) in regulating CsrA activity, a global post-transcriptional regulator. NanoHPLC-MS/MS identified Lys38 (K38), a highly conserved residue within the CsrA RNA-binding interface, as a functional succinylation site. Site-directed mutagenesis revealed that K38 succinylation significantly inhibits biofilm formation by reducing c-di-GMP levels, exopolysaccharide production, and surface hydrophobicity, while enhancing flagellar-mediated motility. Colonization assays on foods, contact surfaces, and the rhizosphere confirmed that CsrA succinylation restricts biofilm formation across diverse ecological niches. These results identify K38 succinylation of CsrA as a regulatory modification that modulates the transition between motile and sessile lifestyles in P. fluorescens PF08. These findings expand the understanding of post-translational control of biofilm formation in this ecologically versatile bacterium relevant to food spoilage and agricultural environments.},
}
RevDate: 2026-07-02
Biofilm formation: Regulatory mechanisms and therapeutic strategies.
Microbiological research, 311:128597 pii:S0944-5013(26)00161-8 [Epub ahead of print].
Biofilm formation and development are dynamically regulated processes. The core regulation involves cell-to-cell communication mediated by quorum-sensing (QS) mechanisms and enhanced intrinsic resistance via efflux pumps. These mechanisms establish a robust barrier against antibiotics and host immune responses. In response, strategies for biofilm eradication have evolved from singular antimicrobial interventions to interdisciplinary synergistic approaches. Current research primarily focuses on synergistic combined therapies that integrate advanced nanoplatforms with physical field interventions. This review has refined an integrated intervention strategy of internal and external collaboration, using internal molecular targeting for precise localization and external physical fields for powerful disintegration, thereby achieving synergistic effects of physical structure destruction, signal pathway interference, and precise drug release. This review systematically summarizes the mechanisms of biofilm formation and regulation, integrates the bidirectional interactive regulatory network of QS and c-di-GMP, and clarifies the dual roles of efflux pumps in biofilms-direct resistance and indirect regulation. With a particular emphasis on the latest advancements, synergistic mechanisms, and prevailing challenges associated with multimodal eradication strategies, proposes a future research roadmap that progresses from omics and in situ imaging to the identification of new targets and ultimately to the development of intelligent responsive systems. It aims to provide a theoretical reference and insights for developing the next generation of efficient and precise therapies for biofilm-associated infections.
Additional Links: PMID-42391941
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PubMed:
Citation:
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@article {pmid42391941,
year = {2026},
author = {Ma, W and Zhang, J and Cheng, Y and Zhai, M and Zhou, J and Qu, J},
title = {Biofilm formation: Regulatory mechanisms and therapeutic strategies.},
journal = {Microbiological research},
volume = {311},
number = {},
pages = {128597},
doi = {10.1016/j.micres.2026.128597},
pmid = {42391941},
issn = {1618-0623},
abstract = {Biofilm formation and development are dynamically regulated processes. The core regulation involves cell-to-cell communication mediated by quorum-sensing (QS) mechanisms and enhanced intrinsic resistance via efflux pumps. These mechanisms establish a robust barrier against antibiotics and host immune responses. In response, strategies for biofilm eradication have evolved from singular antimicrobial interventions to interdisciplinary synergistic approaches. Current research primarily focuses on synergistic combined therapies that integrate advanced nanoplatforms with physical field interventions. This review has refined an integrated intervention strategy of internal and external collaboration, using internal molecular targeting for precise localization and external physical fields for powerful disintegration, thereby achieving synergistic effects of physical structure destruction, signal pathway interference, and precise drug release. This review systematically summarizes the mechanisms of biofilm formation and regulation, integrates the bidirectional interactive regulatory network of QS and c-di-GMP, and clarifies the dual roles of efflux pumps in biofilms-direct resistance and indirect regulation. With a particular emphasis on the latest advancements, synergistic mechanisms, and prevailing challenges associated with multimodal eradication strategies, proposes a future research roadmap that progresses from omics and in situ imaging to the identification of new targets and ultimately to the development of intelligent responsive systems. It aims to provide a theoretical reference and insights for developing the next generation of efficient and precise therapies for biofilm-associated infections.},
}
RevDate: 2026-07-03
CmpDate: 2026-07-03
L-fucose-dependent biofilm formation by Escherichia coli enhances polymicrobial interactions and antibiotic tolerance on urinary catheters.
Biofilm, 12:100378.
Urinary tract infections are common healthcare associated infections, a large subset of which are caused by indwelling catheters. Long term catheterization causes persistent, asymptomatic, polymicrobial colonization despite catheters changes and antibiotic usage. In these polymicrobial populations, P. mirabilis, E. faecalis, and E. coli were found as the most common co-colonizing species. We investigated how interactions between P. mirabilis, E. coli, and E. faecalis contribute to biofilm formation and colonization of urinary catheters. Our results show that the interaction between these three species leads to enhanced biofilm biomass driven by an increase in total protein content of the biofilm. Biofilm enhancement required all three species and was also media-dependent, especially for dual-species combinations. Importantly, triple species biofilms also demonstrate biofilm enhancement when established under flow conditions in a biofilm reactor model using silicone urinary catheters. Additionally, triple species biofilm enhancement occurred in co-colonizing isolates from catheterized patients and was found to be specific to interactions between these three species. Triple species biofilms also demonstrated a species-dependent resistance to two commonly used antibiotics, ciprofloxacin and nitrofurantoin. By examining priority effects, E. coli was found to be the main facilitator of biofilm enhancement in a flow model. Finally, proteomics revealed that an L-fucose utilization pathway in E. coli was a key contributor to triple species biofilm enhancement. Overall, our results demonstrate the significant impact of polymicrobial interactions on biofilm formation in the catheterized environment and highlight ways in which complex microbial interplay and priority effects can shape the establishment of persistent colonization.
Additional Links: PMID-42395168
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@article {pmid42395168,
year = {2026},
author = {Taddei, SM and Deka, N and Marin, A and Hunt, BC and Guterman, LB and Ma, M and Qu, J and Armbruster, CE},
title = {L-fucose-dependent biofilm formation by Escherichia coli enhances polymicrobial interactions and antibiotic tolerance on urinary catheters.},
journal = {Biofilm},
volume = {12},
number = {},
pages = {100378},
pmid = {42395168},
issn = {2590-2075},
abstract = {Urinary tract infections are common healthcare associated infections, a large subset of which are caused by indwelling catheters. Long term catheterization causes persistent, asymptomatic, polymicrobial colonization despite catheters changes and antibiotic usage. In these polymicrobial populations, P. mirabilis, E. faecalis, and E. coli were found as the most common co-colonizing species. We investigated how interactions between P. mirabilis, E. coli, and E. faecalis contribute to biofilm formation and colonization of urinary catheters. Our results show that the interaction between these three species leads to enhanced biofilm biomass driven by an increase in total protein content of the biofilm. Biofilm enhancement required all three species and was also media-dependent, especially for dual-species combinations. Importantly, triple species biofilms also demonstrate biofilm enhancement when established under flow conditions in a biofilm reactor model using silicone urinary catheters. Additionally, triple species biofilm enhancement occurred in co-colonizing isolates from catheterized patients and was found to be specific to interactions between these three species. Triple species biofilms also demonstrated a species-dependent resistance to two commonly used antibiotics, ciprofloxacin and nitrofurantoin. By examining priority effects, E. coli was found to be the main facilitator of biofilm enhancement in a flow model. Finally, proteomics revealed that an L-fucose utilization pathway in E. coli was a key contributor to triple species biofilm enhancement. Overall, our results demonstrate the significant impact of polymicrobial interactions on biofilm formation in the catheterized environment and highlight ways in which complex microbial interplay and priority effects can shape the establishment of persistent colonization.},
}
RevDate: 2026-07-03
CmpDate: 2026-07-03
Shigella's c-di-GMP specific PDEs Modulate Biofilm and Virulence Phenotypes.
bioRxiv : the preprint server for biology pii:2026.06.22.733758.
To establish infection and cause disease, the intracellular pathogen Shigella must successfully navigate a series of host defenses and distinct microenvironments within the human body. One way Shigella navigates these environments is by using the secondary messenger c-di-GMP, which regulates many different bacterial behaviours. C-di-GMP is synthesized by diguanylate cyclases (DGCs) and broken down by c-di-GMP specific phosphodiesterases (PDEs). In this study, we investigated how Shigellas c-di-GMP specific PDEs impact c-di-GMP turn-over and subsequently biofilm and virulence phenotypes. We knocked out each of Shigellas six c-di-GMP specific PDEs to determine how these PDEs impact biofilm, virulence and c-di-GMP levels within the bacterial cell. We found that these PDEs negatively regulate c-di-GMP levels while modulating Shigellas virulence and biofilm behaviour. We also noted that altering expression of these Shigella PDEs changes bacterial cell size. Transcriptome analysis revealed that a Shigella Δ pdeB strain showed reduced expression of many genes, including the virulence genes ipgD and ipgE , as well as genes associated with lipid metabolism. We confirmed that a Shigella Δ pdeB strain had altered levels of stearic acid, and expression of pdeB alters Shigella antibiotic susceptibility. This study highlights the complexities of c-di-GMP signaling in regulating numerous Shigella pathways.
Additional Links: PMID-42395518
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@article {pmid42395518,
year = {2026},
author = {Churaman, CN and Angelica, B and Thompson, AW and Koestler, BJ},
title = {Shigella's c-di-GMP specific PDEs Modulate Biofilm and Virulence Phenotypes.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.64898/2026.06.22.733758},
pmid = {42395518},
issn = {2692-8205},
abstract = {To establish infection and cause disease, the intracellular pathogen Shigella must successfully navigate a series of host defenses and distinct microenvironments within the human body. One way Shigella navigates these environments is by using the secondary messenger c-di-GMP, which regulates many different bacterial behaviours. C-di-GMP is synthesized by diguanylate cyclases (DGCs) and broken down by c-di-GMP specific phosphodiesterases (PDEs). In this study, we investigated how Shigellas c-di-GMP specific PDEs impact c-di-GMP turn-over and subsequently biofilm and virulence phenotypes. We knocked out each of Shigellas six c-di-GMP specific PDEs to determine how these PDEs impact biofilm, virulence and c-di-GMP levels within the bacterial cell. We found that these PDEs negatively regulate c-di-GMP levels while modulating Shigellas virulence and biofilm behaviour. We also noted that altering expression of these Shigella PDEs changes bacterial cell size. Transcriptome analysis revealed that a Shigella Δ pdeB strain showed reduced expression of many genes, including the virulence genes ipgD and ipgE , as well as genes associated with lipid metabolism. We confirmed that a Shigella Δ pdeB strain had altered levels of stearic acid, and expression of pdeB alters Shigella antibiotic susceptibility. This study highlights the complexities of c-di-GMP signaling in regulating numerous Shigella pathways.},
}
RevDate: 2026-07-01
CmpDate: 2026-07-01
Loss of the type VII secretion ATPase EssC promotes biofilm formation of Staphylococcus aureus under acidic stress.
Biofilm, 12:100376.
Staphylococcus aureus adapts to hostile host-associated niches by dynamically switching between planktonic growth and biofilm lifestyles. Acidic environments, such as the skin surface and intracellular compartments, impose substantial stress on bacterial survival; however, the contribution of the type VII secretion system (T7SS) to biofilm adaptation under acidic conditions remains poorly understood. Here, we investigated the role of the T7SS ATPase EssC in regulating S. aureus biofilm formation under acidic stress. Using an essC deletion mutant in the USA300 background, we demonstrate that loss of EssC markedly enhances biofilm biomass and thickness at pH 5.0, despite reducing bacterial viability within mature biofilms. Mechanistically, essC deletion reprograms multiple stages of biofilm development, including enhanced initial adhesion mediated by upregulated fibronectin-binding proteins (FnBPA and FnBPB), increased intercellular aggregation driven by elevated polysaccharide intercellular adhesin (PIA) production, and biofilm stabilization through augmented autolysis-dependent extracellular DNA release. These phenotypic changes are accompanied by coordinated transcriptional remodeling, characterized by downregulation of the biofilm repressor agr and activation of the arlS-icaA and sigB-icaA regulatory axis. Collectively, our findings uncover an unrecognized link between the T7SS core component EssC and biofilm regulation under acidic stress, highlighting EssC as a potential modulator of S. aureus survival strategies in hostile host microenvironments.
Additional Links: PMID-42381774
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@article {pmid42381774,
year = {2026},
author = {Zhang, Y and Wang, Z and Wei, L and Wang, D and Qu, D and Xie, Y and Wu, Y},
title = {Loss of the type VII secretion ATPase EssC promotes biofilm formation of Staphylococcus aureus under acidic stress.},
journal = {Biofilm},
volume = {12},
number = {},
pages = {100376},
pmid = {42381774},
issn = {2590-2075},
abstract = {Staphylococcus aureus adapts to hostile host-associated niches by dynamically switching between planktonic growth and biofilm lifestyles. Acidic environments, such as the skin surface and intracellular compartments, impose substantial stress on bacterial survival; however, the contribution of the type VII secretion system (T7SS) to biofilm adaptation under acidic conditions remains poorly understood. Here, we investigated the role of the T7SS ATPase EssC in regulating S. aureus biofilm formation under acidic stress. Using an essC deletion mutant in the USA300 background, we demonstrate that loss of EssC markedly enhances biofilm biomass and thickness at pH 5.0, despite reducing bacterial viability within mature biofilms. Mechanistically, essC deletion reprograms multiple stages of biofilm development, including enhanced initial adhesion mediated by upregulated fibronectin-binding proteins (FnBPA and FnBPB), increased intercellular aggregation driven by elevated polysaccharide intercellular adhesin (PIA) production, and biofilm stabilization through augmented autolysis-dependent extracellular DNA release. These phenotypic changes are accompanied by coordinated transcriptional remodeling, characterized by downregulation of the biofilm repressor agr and activation of the arlS-icaA and sigB-icaA regulatory axis. Collectively, our findings uncover an unrecognized link between the T7SS core component EssC and biofilm regulation under acidic stress, highlighting EssC as a potential modulator of S. aureus survival strategies in hostile host microenvironments.},
}
RevDate: 2026-07-01
Coumarin-Mediated Inhibition of Diadenylate Cyclase Correlates with Impaired Biofilm Formation in Streptococcus mutans.
ACS infectious diseases [Epub ahead of print].
Streptococcus mutans diadenylate cyclase (SmDAC) catalyzes the cyclization of two ATP molecules into cyclic di-AMP, a second messenger that regulates many cellular processes including biofilm formation. Aided by structure-based drug design and subsequent structure-activity relationship studies, we identified a coumarin chemotype as low-micromolar inhibitors of SmDAC. Optimized lead compounds inhibited both biofilm formation and planktonic growth of S. mutans. Biofilm inhibition marginally exceeded growth inhibition at tested doses, indicating relative selectivity toward biofilm inhibition. Additionally, the lead inhibitor did not significantly affect the growth and biofilm of representative commensal streptococci in a mixed-species community consisting of S. mutans, S. gordonii, and S. sanguinis at 10 μM, though this selectivity was lower when tested in single-species growth and biofilm conditions. Overall, this study demonstrates that the inhibition of S. mutans' DAC and biofilm by small molecules is a potential strategy for the treatment and prevention of dental caries.
Additional Links: PMID-42383450
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@article {pmid42383450,
year = {2026},
author = {Rojas, EM and Govindan, A and Babu, P and Joseph, S and Zhang, H and Zhu, Y and Boddie, T and Lee, HT and Wu, H and Velu, SE},
title = {Coumarin-Mediated Inhibition of Diadenylate Cyclase Correlates with Impaired Biofilm Formation in Streptococcus mutans.},
journal = {ACS infectious diseases},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsinfecdis.5c00767},
pmid = {42383450},
issn = {2373-8227},
abstract = {Streptococcus mutans diadenylate cyclase (SmDAC) catalyzes the cyclization of two ATP molecules into cyclic di-AMP, a second messenger that regulates many cellular processes including biofilm formation. Aided by structure-based drug design and subsequent structure-activity relationship studies, we identified a coumarin chemotype as low-micromolar inhibitors of SmDAC. Optimized lead compounds inhibited both biofilm formation and planktonic growth of S. mutans. Biofilm inhibition marginally exceeded growth inhibition at tested doses, indicating relative selectivity toward biofilm inhibition. Additionally, the lead inhibitor did not significantly affect the growth and biofilm of representative commensal streptococci in a mixed-species community consisting of S. mutans, S. gordonii, and S. sanguinis at 10 μM, though this selectivity was lower when tested in single-species growth and biofilm conditions. Overall, this study demonstrates that the inhibition of S. mutans' DAC and biofilm by small molecules is a potential strategy for the treatment and prevention of dental caries.},
}
RevDate: 2026-07-01
Preventive action of ketamine alone and in combination with antifungals on Candida biofilm formation in catheters.
International microbiology : the official journal of the Spanish Society for Microbiology [Epub ahead of print].
PURPOSE: This study investigates the repurposing potential of the anesthetic ketamine (KET) as a preventive agent, both alone and in combination with the azoles fluconazole (FLC) and itraconazole (ITR), against Candida spp. biofilms adhering to fragments of peripheral venous catheters.
METHODS: The activity was assessed in vitro through cell viability and colonization assays of impregnated catheter segments, while morphological alterations were analyzed using scanning electron microscopy (SEM).
RESULTS: KET, both alone and in association with ITR, significantly reduced (p < 0.05) the adherence of C. albicans to the impregnated fragments. Furthermore, the combinations KET + FLC and KET + ITR frequently exhibited greater efficacy in reducing biofilm viability than the agents used individually, suggesting additive/synergistic interactions. SEM revealed structural damage to the treated fungal cells.
CONCLUSION: These findings indicate that KET exhibits preventive activity against Candida spp. biofilms, including on catheter surfaces, and may enhance the activity of azoles, positioning it as a promising candidate for repurposing in the treatment of biofilm-associated fungal infections.
Additional Links: PMID-42384304
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@article {pmid42384304,
year = {2026},
author = {da Silva, CR and Sá, LGDAV and da Silva, LJ and Martins, MSM and Silveira, MJCB and da Costa, ÉRM and de Farias Cabral, VP and Rodrigues, DS and Moreira, LEA and Matos, VM and Dos Santos, VG and Nobre, HV and de Andrade Neto, JB},
title = {Preventive action of ketamine alone and in combination with antifungals on Candida biofilm formation in catheters.},
journal = {International microbiology : the official journal of the Spanish Society for Microbiology},
volume = {},
number = {},
pages = {},
pmid = {42384304},
issn = {1618-1905},
abstract = {PURPOSE: This study investigates the repurposing potential of the anesthetic ketamine (KET) as a preventive agent, both alone and in combination with the azoles fluconazole (FLC) and itraconazole (ITR), against Candida spp. biofilms adhering to fragments of peripheral venous catheters.
METHODS: The activity was assessed in vitro through cell viability and colonization assays of impregnated catheter segments, while morphological alterations were analyzed using scanning electron microscopy (SEM).
RESULTS: KET, both alone and in association with ITR, significantly reduced (p < 0.05) the adherence of C. albicans to the impregnated fragments. Furthermore, the combinations KET + FLC and KET + ITR frequently exhibited greater efficacy in reducing biofilm viability than the agents used individually, suggesting additive/synergistic interactions. SEM revealed structural damage to the treated fungal cells.
CONCLUSION: These findings indicate that KET exhibits preventive activity against Candida spp. biofilms, including on catheter surfaces, and may enhance the activity of azoles, positioning it as a promising candidate for repurposing in the treatment of biofilm-associated fungal infections.},
}
RevDate: 2026-07-01
Anti-biofilm activity of coated zinc oxide nanoparticles in a water-in-oil formulation against Cutibacterium acnes.
Anaerobe pii:S1075-9964(26)00039-9 [Epub ahead of print].
Coated ZnO-NPs demonstrated antibacterial and biofilm-disrupting activities against Cutibacterium acnes in a high-viscosity, skincare-mimicking water-in-oil formulation. They reduced viable biofilm-embedded cell count by more than 100-fold compared to the control formulation. The sebum-exposed in vitro biofilm model provides a practical platform for evaluating anti-biofilm skincare products.
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@article {pmid42386076,
year = {2026},
author = {Iriya, S and Takata, M and Yano, T},
title = {Anti-biofilm activity of coated zinc oxide nanoparticles in a water-in-oil formulation against Cutibacterium acnes.},
journal = {Anaerobe},
volume = {},
number = {},
pages = {103059},
doi = {10.1016/j.anaerobe.2026.103059},
pmid = {42386076},
issn = {1095-8274},
abstract = {Coated ZnO-NPs demonstrated antibacterial and biofilm-disrupting activities against Cutibacterium acnes in a high-viscosity, skincare-mimicking water-in-oil formulation. They reduced viable biofilm-embedded cell count by more than 100-fold compared to the control formulation. The sebum-exposed in vitro biofilm model provides a practical platform for evaluating anti-biofilm skincare products.},
}
RevDate: 2026-07-02
CmpDate: 2026-07-02
Clinical Impact of Biofilm-Producing Carbapenem-Resistant Acinetobacter baumannii: Diagnosis and Treatment Challenges.
Cureus, 18(6):e110019.
Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a major nosocomial pathogen associated with significant morbidity and mortality, particularly in intensive care unit (ICU) settings. Its remarkable ability to survive in adverse environments, persist on medical devices, and rapidly acquire multidrug resistance has made it a critical global healthcare concern. This review aims to provide a comprehensive overview of the epidemiology, risk factors, antimicrobial resistance mechanisms, and pathogenicity of CRAB, with a special emphasis on the role of biofilm formation. CRAB infections are strongly associated with prolonged hospitalization, mechanical ventilation, previous antibiotic exposure, and invasive procedures. The organism exhibits multiple resistance mechanisms, including carbapenemase production, efflux pumps, porin modifications, and horizontal gene transfer, which significantly limit therapeutic options. A key virulence factor is its capacity to form biofilms on biotic and abiotic surfaces, enhancing bacterial survival, immune evasion, and resistance to antimicrobial agents. Biofilm-associated infections are often chronic, recurrent, and difficult to eradicate, particularly in device-related infections. The interplay between biofilm formation and antimicrobial resistance further complicates treatment outcomes. Current management strategies rely on last-resort antibiotics, combination therapy, antimicrobial stewardship, and strict infection control practices, while emerging therapies targeting biofilms offer promising alternatives. Understanding these complex mechanisms is essential for developing effective therapeutic and preventive strategies against CRAB infections.
Additional Links: PMID-42388939
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@article {pmid42388939,
year = {2026},
author = {Bhati, DG and Patil, HV and Patil, SR},
title = {Clinical Impact of Biofilm-Producing Carbapenem-Resistant Acinetobacter baumannii: Diagnosis and Treatment Challenges.},
journal = {Cureus},
volume = {18},
number = {6},
pages = {e110019},
pmid = {42388939},
issn = {2168-8184},
abstract = {Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a major nosocomial pathogen associated with significant morbidity and mortality, particularly in intensive care unit (ICU) settings. Its remarkable ability to survive in adverse environments, persist on medical devices, and rapidly acquire multidrug resistance has made it a critical global healthcare concern. This review aims to provide a comprehensive overview of the epidemiology, risk factors, antimicrobial resistance mechanisms, and pathogenicity of CRAB, with a special emphasis on the role of biofilm formation. CRAB infections are strongly associated with prolonged hospitalization, mechanical ventilation, previous antibiotic exposure, and invasive procedures. The organism exhibits multiple resistance mechanisms, including carbapenemase production, efflux pumps, porin modifications, and horizontal gene transfer, which significantly limit therapeutic options. A key virulence factor is its capacity to form biofilms on biotic and abiotic surfaces, enhancing bacterial survival, immune evasion, and resistance to antimicrobial agents. Biofilm-associated infections are often chronic, recurrent, and difficult to eradicate, particularly in device-related infections. The interplay between biofilm formation and antimicrobial resistance further complicates treatment outcomes. Current management strategies rely on last-resort antibiotics, combination therapy, antimicrobial stewardship, and strict infection control practices, while emerging therapies targeting biofilms offer promising alternatives. Understanding these complex mechanisms is essential for developing effective therapeutic and preventive strategies against CRAB infections.},
}
RevDate: 2026-07-02
CmpDate: 2026-07-02
Assessment of antibacterial and anti-biofilm activities of marine fungal epiphytes associated with red and green algae of the Kenyan coast.
Biotechnology notes (Amsterdam, Netherlands), 7:120-141.
Marine-derived fungal epiphytes represent an important yet largely unexplored source of bioactive compounds. This study investigates the antibacterial and anti-biofilm properties of cultivable fungal epiphytes associated with red and green algae collected from a single coastal site in Kenya. A total of 330 fungal isolates were initially identified based on their morphological characteristics. Following agar-plug screening, nine active isolates have been identified through ITS-rDNA sequencing. Ethyl acetate and methanolic fungal extracts were evaluated against six multidrug-resistant microorganisms using disc diffusion, MIC, MBC, and microtiter biofilm disruption assays. The five best-performing extracts were subjected to SEM imaging, with two (Cer sp-2 and Ulr-1) further analyzed via GC-MS. Extracts from both solvents showed remarkable antibacterial effects, producing zones of inhibition that spanned between 10.00 ± 0.00 and 29.00 ± 0.00 mm. Furthermore, MIC and MBC assays revealed strong activity, with the lowest recorded values being 0.039 mg/mL and 0.156 mg/mL, respectively. Scanning electron microscopy (SEM) analysis displayed structural changes in bacterial cells, supporting a membrane-targeting mechanism of action. They also exhibited significant anti-biofilm properties (P < 0.05-0.0001) compared to the PBS-treated control. Although most biofilm reduction percentages were relatively low, the extracts displayed measurable activity in disrupting pre-formed biofilms. GC-MS identified a diverse profile of bioactive metabolites in the two representative extracts. Overall, Kenyan coastal algae harbor bioactive fungal epiphytes with promising potential to combat multidrug-resistant and biofilm-forming pathogens. Comprehensive studies are needed to discover novel therapeutic candidates in the future.
Additional Links: PMID-42389493
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@article {pmid42389493,
year = {2026},
author = {Sendekie, AZ and Nyerere, KA and Kaaria, PK},
title = {Assessment of antibacterial and anti-biofilm activities of marine fungal epiphytes associated with red and green algae of the Kenyan coast.},
journal = {Biotechnology notes (Amsterdam, Netherlands)},
volume = {7},
number = {},
pages = {120-141},
pmid = {42389493},
issn = {2665-9069},
abstract = {Marine-derived fungal epiphytes represent an important yet largely unexplored source of bioactive compounds. This study investigates the antibacterial and anti-biofilm properties of cultivable fungal epiphytes associated with red and green algae collected from a single coastal site in Kenya. A total of 330 fungal isolates were initially identified based on their morphological characteristics. Following agar-plug screening, nine active isolates have been identified through ITS-rDNA sequencing. Ethyl acetate and methanolic fungal extracts were evaluated against six multidrug-resistant microorganisms using disc diffusion, MIC, MBC, and microtiter biofilm disruption assays. The five best-performing extracts were subjected to SEM imaging, with two (Cer sp-2 and Ulr-1) further analyzed via GC-MS. Extracts from both solvents showed remarkable antibacterial effects, producing zones of inhibition that spanned between 10.00 ± 0.00 and 29.00 ± 0.00 mm. Furthermore, MIC and MBC assays revealed strong activity, with the lowest recorded values being 0.039 mg/mL and 0.156 mg/mL, respectively. Scanning electron microscopy (SEM) analysis displayed structural changes in bacterial cells, supporting a membrane-targeting mechanism of action. They also exhibited significant anti-biofilm properties (P < 0.05-0.0001) compared to the PBS-treated control. Although most biofilm reduction percentages were relatively low, the extracts displayed measurable activity in disrupting pre-formed biofilms. GC-MS identified a diverse profile of bioactive metabolites in the two representative extracts. Overall, Kenyan coastal algae harbor bioactive fungal epiphytes with promising potential to combat multidrug-resistant and biofilm-forming pathogens. Comprehensive studies are needed to discover novel therapeutic candidates in the future.},
}
RevDate: 2026-07-02
Correction: Metagenomic and ribosomal transcript profiles of diabetic foot osteomyelitis in Hispanic patients: underestimated bacteria in biofilm persistence.
Frontiers in cellular and infection microbiology, 16:1902309.
[This corrects the article DOI: 10.3389/fcimb.2025.1729196.].
Additional Links: PMID-42389512
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@article {pmid42389512,
year = {2026},
author = {Díaz-Velis, L and Salvador-Sagüez, F and Roach, F and Mancilla, E and Campos, MA and Ruiz-Gil, T and López-Moral, M and Lázaro-Martínez, JL},
title = {Correction: Metagenomic and ribosomal transcript profiles of diabetic foot osteomyelitis in Hispanic patients: underestimated bacteria in biofilm persistence.},
journal = {Frontiers in cellular and infection microbiology},
volume = {16},
number = {},
pages = {1902309},
doi = {10.3389/fcimb.2026.1902309},
pmid = {42389512},
issn = {2235-2988},
abstract = {[This corrects the article DOI: 10.3389/fcimb.2025.1729196.].},
}
RevDate: 2026-07-02
CmpDate: 2026-07-02
Genomic insights into activated antimicrobial resistance of in situ hospital-wastewater biofilm.
Biofilm, 12:100377.
Antimicrobial resistance (AMR), particularly among carbapenemase-producing organisms, poses a major global health threat. Although hospital wastewater is considered an AMR hotspot, its functional contribution to resistance dynamics remains poorly defined. We developed in situ biofilms in hospital wastewater and applied integrated metagenomic, metatranscriptomic, and culture-based analyses to characterize community structure and gene expression. Biofilms exhibited greater biomass and higher contamination with extended-spectrum β-lactamase-producing Escherichia coli than planktonic wastewater. Biofilms were enriched in surface-adapted Flavobacteriaceae species and a broader array of carbapenemase genes, whereas wastewater showed higher abundance of gut-associated Bacteroidaceae species and virulence factors. Mobile genetic elements linked multiple AMR genes and showed increased expression in biofilms, including bla IMP family carbapenemases. Culture confirmed bla IMP-1 in four biofilm isolates and one wastewater isolate. These findings indicate that hospital-wastewater biofilms can serve as important reservoirs that promote the persistence and potential dissemination of clinically relevant carbapenem resistance.
Additional Links: PMID-42389745
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@article {pmid42389745,
year = {2026},
author = {Ota, Y and Nukui, Y and Gu, Y and Saito, R},
title = {Genomic insights into activated antimicrobial resistance of in situ hospital-wastewater biofilm.},
journal = {Biofilm},
volume = {12},
number = {},
pages = {100377},
pmid = {42389745},
issn = {2590-2075},
abstract = {Antimicrobial resistance (AMR), particularly among carbapenemase-producing organisms, poses a major global health threat. Although hospital wastewater is considered an AMR hotspot, its functional contribution to resistance dynamics remains poorly defined. We developed in situ biofilms in hospital wastewater and applied integrated metagenomic, metatranscriptomic, and culture-based analyses to characterize community structure and gene expression. Biofilms exhibited greater biomass and higher contamination with extended-spectrum β-lactamase-producing Escherichia coli than planktonic wastewater. Biofilms were enriched in surface-adapted Flavobacteriaceae species and a broader array of carbapenemase genes, whereas wastewater showed higher abundance of gut-associated Bacteroidaceae species and virulence factors. Mobile genetic elements linked multiple AMR genes and showed increased expression in biofilms, including bla IMP family carbapenemases. Culture confirmed bla IMP-1 in four biofilm isolates and one wastewater isolate. These findings indicate that hospital-wastewater biofilms can serve as important reservoirs that promote the persistence and potential dissemination of clinically relevant carbapenem resistance.},
}
RevDate: 2026-06-30
The Influence of Psychological Factors on Biofilm-Related Oral Outcomes in Adults: A Systematic Review of Prospective Studies.
Journal of dentistry pii:S0300-5712(26)00539-7 [Epub ahead of print].
OBJECTIVE: The present systematic review aimed to determine whether psychological factors are associated with subsequent biofilm-related oral health outcomes in adults.
DATA: The review followed PRISMA guidelines. The protocol was registered in PROSPERO (CRD420251119213). Risk of bias was assessed using the NHLBI tool.
SOURCES: MEDLINE, PsycINFO, and Web of Science were searched through May 2026.
STUDY SELECTION: Eligible prospective longitudinal studies in adults assessed a broad range of psychological exposures (e.g., depression, anxiety, stress, self-efficacy, health beliefs, personality traits, and sense of coherence) before oral outcomes. Outcomes included periodontal parameters, dental caries, tooth loss, and oral-hygiene behaviours.
RESULTS: Ten prospective studies of fair-to-good quality were included. Findings for cognitive constructs were mixed: self-efficacy was associated with subsequent self-reported oral hygiene behaviours and, following motivation and oral hygiene instruction, clinically assessed plaque control, but not consistently across studies or outcomes; perceived treatment benefits, particularly when combined with perceived susceptibility, and Theory of Reasoned Action variables were associated with subsequent gingival or plaque outcomes. Data on psychopathology were sparse but suggested associations of depression and stress with poorer oral self-care and periodontal outcomes. A small number of studies also indicated possible relationships between personality traits and periodontal and caries outcomes, whereas the only study assessing sense of coherence found no association.
CONCLUSIONS: Prospective associations with oral health behaviours or clinical outcomes were observed for several of the psychological constructs examined, although the evidence base remains limited and heterogeneous. More robust longitudinal studies are needed to clarify these relationships across different oral diseases.
CLINICAL SIGNIFICANCE: Available prospective evidence suggests that psychological factors may play a role in subsequent oral hygiene behaviours, periodontal outcomes, and treatment response. These findings may inform future research on risk assessment and personalised preventive care.
Additional Links: PMID-42379258
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@article {pmid42379258,
year = {2026},
author = {Valeriani, L and Liguori, MG and Giovannini, A and Montevecchi, M and Covelli, V},
title = {The Influence of Psychological Factors on Biofilm-Related Oral Outcomes in Adults: A Systematic Review of Prospective Studies.},
journal = {Journal of dentistry},
volume = {},
number = {},
pages = {106869},
doi = {10.1016/j.jdent.2026.106869},
pmid = {42379258},
issn = {1879-176X},
abstract = {OBJECTIVE: The present systematic review aimed to determine whether psychological factors are associated with subsequent biofilm-related oral health outcomes in adults.
DATA: The review followed PRISMA guidelines. The protocol was registered in PROSPERO (CRD420251119213). Risk of bias was assessed using the NHLBI tool.
SOURCES: MEDLINE, PsycINFO, and Web of Science were searched through May 2026.
STUDY SELECTION: Eligible prospective longitudinal studies in adults assessed a broad range of psychological exposures (e.g., depression, anxiety, stress, self-efficacy, health beliefs, personality traits, and sense of coherence) before oral outcomes. Outcomes included periodontal parameters, dental caries, tooth loss, and oral-hygiene behaviours.
RESULTS: Ten prospective studies of fair-to-good quality were included. Findings for cognitive constructs were mixed: self-efficacy was associated with subsequent self-reported oral hygiene behaviours and, following motivation and oral hygiene instruction, clinically assessed plaque control, but not consistently across studies or outcomes; perceived treatment benefits, particularly when combined with perceived susceptibility, and Theory of Reasoned Action variables were associated with subsequent gingival or plaque outcomes. Data on psychopathology were sparse but suggested associations of depression and stress with poorer oral self-care and periodontal outcomes. A small number of studies also indicated possible relationships between personality traits and periodontal and caries outcomes, whereas the only study assessing sense of coherence found no association.
CONCLUSIONS: Prospective associations with oral health behaviours or clinical outcomes were observed for several of the psychological constructs examined, although the evidence base remains limited and heterogeneous. More robust longitudinal studies are needed to clarify these relationships across different oral diseases.
CLINICAL SIGNIFICANCE: Available prospective evidence suggests that psychological factors may play a role in subsequent oral hygiene behaviours, periodontal outcomes, and treatment response. These findings may inform future research on risk assessment and personalised preventive care.},
}
RevDate: 2026-06-30
Transmission of Dry Surface Biofilm Via and Through Cotton Bedsheets: Implications for Hospital Infection Control.
The Journal of hospital infection pii:S0195-6701(26)00262-8 [Epub ahead of print].
BACKGROUND: Dry surface biofilms (DSB) have been found to persist on hospital beds and pillows.
AIM: This study aimed to investigate whether cotton bedsheets prevent transmission of DSB-related pathogens to patients.
METHODS: Staphylococcus aureus DSB was cultured on polycarbonate coupons. DSB transmission was simulated via 150 or 250 threads/in[2] cotton bedsheets directly onto surfaces, or through cotton sheets onto hands and then onto surfaces, both before and after neutral detergent treatment by CFU counts. qPCR and SEM were used to evaluate bacterial biofilm contamination on hospital mattresses and pillow covers.
FINDINGS: Lab simulations: Bacterial transfer counts (CFU) differed significantly across all experimental conditions. Specifically, bacterial transmission was significantly higher for cotton sheets with a thread count of 150 threads/in[2] compared to those with 250 threads/in[2] (p < 0.001). Additionally, transmission was significantly greater for wet sheets (post-detergent treatment) than for dry sheets (p < 0.001), and significantly higher for direct touch than for contact through the sheets (p < 0.001). CLINICAL SAMPLES: qPCR detected 1.1×10[5]±6.8×10[4] bacteria/cm[2] on mattress covers and 7.5±3.7×10[4] bacteria/cm[2] on pillow covers; SEM directly visualized DSB embedded in surface pits of mattress covers, confirming real-world clinical contamination.
CONCLUSION: Cotton bedsheets show high transmissibility for DSB, especially when wet. DSB can persist on mattresses and could be transmitted through bedsheets, highlighting the need for rigorous cleaning, frequent sheet changes, and higher-thread-count sheets to reduce pathogen transmission and hospital-acquired infections.
Additional Links: PMID-42379307
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@article {pmid42379307,
year = {2026},
author = {Chowdhury, D and Tahir, S and Legge, M and Wang, M and Deva, AK and Vickery, K and Hu, H},
title = {Transmission of Dry Surface Biofilm Via and Through Cotton Bedsheets: Implications for Hospital Infection Control.},
journal = {The Journal of hospital infection},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jhin.2026.06.019},
pmid = {42379307},
issn = {1532-2939},
abstract = {BACKGROUND: Dry surface biofilms (DSB) have been found to persist on hospital beds and pillows.
AIM: This study aimed to investigate whether cotton bedsheets prevent transmission of DSB-related pathogens to patients.
METHODS: Staphylococcus aureus DSB was cultured on polycarbonate coupons. DSB transmission was simulated via 150 or 250 threads/in[2] cotton bedsheets directly onto surfaces, or through cotton sheets onto hands and then onto surfaces, both before and after neutral detergent treatment by CFU counts. qPCR and SEM were used to evaluate bacterial biofilm contamination on hospital mattresses and pillow covers.
FINDINGS: Lab simulations: Bacterial transfer counts (CFU) differed significantly across all experimental conditions. Specifically, bacterial transmission was significantly higher for cotton sheets with a thread count of 150 threads/in[2] compared to those with 250 threads/in[2] (p < 0.001). Additionally, transmission was significantly greater for wet sheets (post-detergent treatment) than for dry sheets (p < 0.001), and significantly higher for direct touch than for contact through the sheets (p < 0.001). CLINICAL SAMPLES: qPCR detected 1.1×10[5]±6.8×10[4] bacteria/cm[2] on mattress covers and 7.5±3.7×10[4] bacteria/cm[2] on pillow covers; SEM directly visualized DSB embedded in surface pits of mattress covers, confirming real-world clinical contamination.
CONCLUSION: Cotton bedsheets show high transmissibility for DSB, especially when wet. DSB can persist on mattresses and could be transmitted through bedsheets, highlighting the need for rigorous cleaning, frequent sheet changes, and higher-thread-count sheets to reduce pathogen transmission and hospital-acquired infections.},
}
RevDate: 2026-06-30
2H-Chromen-2-one Disrupts the Staphylococcus aureus Biofilm Matrix and Potentiates Moxifloxacin Activity: In Vitro and In Silico Analyses.
Microbial pathogenesis pii:S0882-4010(26)00392-X [Epub ahead of print].
OBJECTIVES: Staphylococcus aureus biofilms contribute to antimicrobial tolerance and treatment failure, motivating the search for antibiofilm adjuvants that restore antibiotic activity. In this study, we evaluated 2H-chromen-2-one isolated from Aspidistra letrea for its antibiofilm activity and its ability to potentiate moxifloxacin (MXF) against S. aureus biofilms.
METHODS: Established biofilms were quantified by total biomass (crystal violet staining) and viable bacteria (CFU enumeration) following exposure to 2H-chromen-2-one alone or in combination with MXF, including testing MXF at a clinically relevant peak concentration (Cmax). Molecular docking was performed against proteins encoded by the ica locus to explore potential molecular targets.
RESULTS: 2H-chromen-2-one reduced biofilm biomass by approximately 50% at 1-2 mg/mL and markedly increased MXF antibiofilm killing in a concentration-dependent manner. Notably, MXF alone showed minimal killing at Cmax, whereas co-treatment achieved a reduction of up to approximately 1.6 log10 CFU/mL (>97% killing) and reduced the bactericidal concentration requirement from >1.5 to 0.032 mg/L. Moreover, the maximal reduction efficacy of MXF increased from approximately -2 log10 CFU/mL when MXF was used alone to approximately -3 log10 CFU/mL when combined with 2H-chromen-2-one. Docking suggested a putative interaction between 2H-chromen-2-one and IcaC, consistent with interference in poly-N-acetylglucosamine (PNAG)-associated matrix biology.
CONCLUSIONS: Collectively, these data indicate that 2H-chromen-2-one is a promising antibiofilm adjuvant that can sensitize S. aureus biofilms to moxifloxacin, supporting its further validation in clinical isolates and in vivo models.
Additional Links: PMID-42379479
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@article {pmid42379479,
year = {2026},
author = {Khanh, LN and Anh, NTL and Quynh, NTN and Nguyen, TT and Ho, DV and Hoai, NT and Huong, PT and Nguyen, TK},
title = {2H-Chromen-2-one Disrupts the Staphylococcus aureus Biofilm Matrix and Potentiates Moxifloxacin Activity: In Vitro and In Silico Analyses.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {108666},
doi = {10.1016/j.micpath.2026.108666},
pmid = {42379479},
issn = {1096-1208},
abstract = {OBJECTIVES: Staphylococcus aureus biofilms contribute to antimicrobial tolerance and treatment failure, motivating the search for antibiofilm adjuvants that restore antibiotic activity. In this study, we evaluated 2H-chromen-2-one isolated from Aspidistra letrea for its antibiofilm activity and its ability to potentiate moxifloxacin (MXF) against S. aureus biofilms.
METHODS: Established biofilms were quantified by total biomass (crystal violet staining) and viable bacteria (CFU enumeration) following exposure to 2H-chromen-2-one alone or in combination with MXF, including testing MXF at a clinically relevant peak concentration (Cmax). Molecular docking was performed against proteins encoded by the ica locus to explore potential molecular targets.
RESULTS: 2H-chromen-2-one reduced biofilm biomass by approximately 50% at 1-2 mg/mL and markedly increased MXF antibiofilm killing in a concentration-dependent manner. Notably, MXF alone showed minimal killing at Cmax, whereas co-treatment achieved a reduction of up to approximately 1.6 log10 CFU/mL (>97% killing) and reduced the bactericidal concentration requirement from >1.5 to 0.032 mg/L. Moreover, the maximal reduction efficacy of MXF increased from approximately -2 log10 CFU/mL when MXF was used alone to approximately -3 log10 CFU/mL when combined with 2H-chromen-2-one. Docking suggested a putative interaction between 2H-chromen-2-one and IcaC, consistent with interference in poly-N-acetylglucosamine (PNAG)-associated matrix biology.
CONCLUSIONS: Collectively, these data indicate that 2H-chromen-2-one is a promising antibiofilm adjuvant that can sensitize S. aureus biofilms to moxifloxacin, supporting its further validation in clinical isolates and in vivo models.},
}
RevDate: 2026-06-30
Palladium(II) complexes suppress biofilm formation and virulence in multidrug-resistant Staphylococcus aureus.
Scientific reports pii:10.1038/s41598-026-59550-3 [Epub ahead of print].
The increasing prevalence of multidrug-resistant Staphylococcus aureus (MDRSA) and its ability to form biofilms on host tissues and indwelling devices necessitate the development of alternative therapeutic strategies beyond conventional bactericidal approaches. Two series of palladium(II) metal complexes, derived from α-picolinic acid and substituted anilines, namely QSL_Pd[1A] to QSL_Pd[6A] and QSL_Pd[1B] to QSL_Pd[6B], were tested for their efficacy against multidrug-resistant (MDR) clinical isolates of S.aureus, SA P1966 and SA 2040, and their mechanism of action was elucidated. Among the complexes, QSL_Pd[4A] emerged as a potent lead, effectively suppressing biofilm formation with an MBIC50 of 6.26-0.74 µg/mL across both isolates in association with reduced extracellular polymeric substance production and lower cell surface hydrophobicity, without inducing reactive oxygen species. Gene expression analysis revealed downregulation of sarA and icaA, while the agr system remained unaffected. Notably, combinatorial therapy demonstrated a synergistic interaction with commercially available antibiotics, resensitizing the strains. Together, these findings highlight QSL_Pd[4A] as a promising antivirulence and antibiofilm agent that attenuates virulence factors, offering a viable strategy to combat MDRSA without exhibiting cytotoxicity.
Additional Links: PMID-42380207
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@article {pmid42380207,
year = {2026},
author = {Shobana, R and Sivaprakash, S and Amali, AJ and Solomon, AP and Suresh, D},
title = {Palladium(II) complexes suppress biofilm formation and virulence in multidrug-resistant Staphylococcus aureus.},
journal = {Scientific reports},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41598-026-59550-3},
pmid = {42380207},
issn = {2045-2322},
abstract = {The increasing prevalence of multidrug-resistant Staphylococcus aureus (MDRSA) and its ability to form biofilms on host tissues and indwelling devices necessitate the development of alternative therapeutic strategies beyond conventional bactericidal approaches. Two series of palladium(II) metal complexes, derived from α-picolinic acid and substituted anilines, namely QSL_Pd[1A] to QSL_Pd[6A] and QSL_Pd[1B] to QSL_Pd[6B], were tested for their efficacy against multidrug-resistant (MDR) clinical isolates of S.aureus, SA P1966 and SA 2040, and their mechanism of action was elucidated. Among the complexes, QSL_Pd[4A] emerged as a potent lead, effectively suppressing biofilm formation with an MBIC50 of 6.26-0.74 µg/mL across both isolates in association with reduced extracellular polymeric substance production and lower cell surface hydrophobicity, without inducing reactive oxygen species. Gene expression analysis revealed downregulation of sarA and icaA, while the agr system remained unaffected. Notably, combinatorial therapy demonstrated a synergistic interaction with commercially available antibiotics, resensitizing the strains. Together, these findings highlight QSL_Pd[4A] as a promising antivirulence and antibiofilm agent that attenuates virulence factors, offering a viable strategy to combat MDRSA without exhibiting cytotoxicity.},
}
RevDate: 2026-07-01
Inhibiting biofilm growth on ammonium salt-functionalized or fluorinated voice prostheses silicone.
Applied microbiology and biotechnology pii:10.1007/s00253-026-13904-z [Epub ahead of print].
Voice prostheses (VPs) are largely limited by their relatively short functional lifespans, mainly due to colonization by heterogeneous fungal-bacterial biofilms. This biofilm-mediated degradation is a major contributor to VP failure and is associated with clinically significant complications such as impaired phonation, leakage through the tracheoesophageal fistula, and an increased risk of pneumonia. We performed a series of in vitro experiments to assess the antimicrobial and physicochemical properties of VPs constructed from quaternary ammonium salt-functionalized or fluorinated silicone. Biofilm development on each prosthesis was quantified by measuring crystal violet-stained biomass, and surface coverage was visualized using scanning electron microscopy. Furthermore, biofilm morphology and material adhesion characteristics were examined by atomic force microscopy. To evaluate cytocompatibility, fibroblasts were exposed to extracts obtained after 24 h incubation of each material in culture medium. This was followed by analysis of cell area, circularity index, haemolytic activity and cytokine secretion. Mechanical testing was performed to determine the physiochemical performance of the tested silicone materials. Crystal violet staining demonstrated substantial biofilm accumulation on VPs retrieved from patients after three months of use. In contrast, the modified silicone materials exhibited markedly reduced biofilm coverage. All tested materials supported normal fibroblast proliferation and showed minimal hemolytic activity, although they differed in their capacity to induce cytokine expression. Incorporation of ammonium salt-functionalised or fluorinated silicone in VP design may substantially reduce surface biofilm formation. Thereby, improving device longevity and decreasing the risk of use-related complications. Key points• Fluorinated and quaternary ammonium salt-modified silicones exhibit significant biofilm resistance.• The modified materials demonstrate established biocompatibility with human cells.• These findings suggest the potential for developing new, extended-lifespan voice prostheses.
Additional Links: PMID-42380509
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@article {pmid42380509,
year = {2026},
author = {Okła, S and Kaliniak, S and Spałek, J and Piotrowska, K and Łysik, D and Deptuła, P and Żochowski, K and Dutkiewicz, M and Mystkowska, J and Wnorowska, U and Bucki, R and Durnaś, B and Madej, M and Maciejewski, H and Góźdź, S},
title = {Inhibiting biofilm growth on ammonium salt-functionalized or fluorinated voice prostheses silicone.},
journal = {Applied microbiology and biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00253-026-13904-z},
pmid = {42380509},
issn = {1432-0614},
abstract = {Voice prostheses (VPs) are largely limited by their relatively short functional lifespans, mainly due to colonization by heterogeneous fungal-bacterial biofilms. This biofilm-mediated degradation is a major contributor to VP failure and is associated with clinically significant complications such as impaired phonation, leakage through the tracheoesophageal fistula, and an increased risk of pneumonia. We performed a series of in vitro experiments to assess the antimicrobial and physicochemical properties of VPs constructed from quaternary ammonium salt-functionalized or fluorinated silicone. Biofilm development on each prosthesis was quantified by measuring crystal violet-stained biomass, and surface coverage was visualized using scanning electron microscopy. Furthermore, biofilm morphology and material adhesion characteristics were examined by atomic force microscopy. To evaluate cytocompatibility, fibroblasts were exposed to extracts obtained after 24 h incubation of each material in culture medium. This was followed by analysis of cell area, circularity index, haemolytic activity and cytokine secretion. Mechanical testing was performed to determine the physiochemical performance of the tested silicone materials. Crystal violet staining demonstrated substantial biofilm accumulation on VPs retrieved from patients after three months of use. In contrast, the modified silicone materials exhibited markedly reduced biofilm coverage. All tested materials supported normal fibroblast proliferation and showed minimal hemolytic activity, although they differed in their capacity to induce cytokine expression. Incorporation of ammonium salt-functionalised or fluorinated silicone in VP design may substantially reduce surface biofilm formation. Thereby, improving device longevity and decreasing the risk of use-related complications. Key points• Fluorinated and quaternary ammonium salt-modified silicones exhibit significant biofilm resistance.• The modified materials demonstrate established biocompatibility with human cells.• These findings suggest the potential for developing new, extended-lifespan voice prostheses.},
}
RevDate: 2026-07-01
CmpDate: 2026-07-01
Effect of a cannabidiol-based mouthwash on dental enamel properties and biofilm control: an In situ study.
Clinical oral investigations, 30(7):.
OBJECTIVES: This study evaluated the antibiofilm activity of experimental mouthwash containing different concentrations of cannabidiol (CBD) and the in situ effects on the physical and mechanical properties of dental enamel.
METHODS: Bovine enamel fragments (6 × 6 × 2 mm) were mounted in intraoral appliances worn by 14 participants in a crossover design. Mouthwash containing CBD (0%, 0.01%, 0.05%, and 0.1%) and 0.12% chlorhexidine (CHX) were tested. Each experimental phase lasted 7 days, separated by washout periods. One side of the appliance was exposed to a cariogenic challenge (20% sucrose) prior to treatment. Surface roughness (Ra), microhardness (%KHN), and color change (ΔE00) were measured before and after treatments. Biofilm and yeast counts (log10 CFU) were quantified, and enamel surfaces were analyzed by scanning electron microscopy. Data were analyzed using two-way ANOVA with Bonferroni post hoc tests and Kruskal-Wallis with Dunn's test (P < 0.05).
RESULTS: Sucrose did not significantly affect Ra (P > 0.05), although CBD 0.1% showed higher roughness than CHX under sucrose exposure (P < 0.05). No significant differences in %KHN were observed among treatments; however, sucrose reduced microhardness in the placebo and CBD 0.01% groups (P < 0.05). CHX exhibited the highest ΔE00 values (P < 0.05). Biofilm formation was similar among CHX, CBD 0.05%, and CBD 0.1% (P > 0.05), while CHX showed lower yeast counts than CBD 0.01% and CBD 0.1% (P < 0.05).
CONCLUSION: CBD 0.05% demonstrated potential for biofilm control without adversely affecting enamel properties.
CLINICAL RELEVANCE: This study provides evidence supporting a natural compound-based mouthwash as a clinically viable alternative to chlorhexidine, showing similar efficacy and no associated adverse effects under the conditions tested.
Additional Links: PMID-42380527
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@article {pmid42380527,
year = {2026},
author = {Pimenta, ALA and de Sousa, LA and Martins, CHG and de Carvalho Panzeri, F},
title = {Effect of a cannabidiol-based mouthwash on dental enamel properties and biofilm control: an In situ study.},
journal = {Clinical oral investigations},
volume = {30},
number = {7},
pages = {},
pmid = {42380527},
issn = {1436-3771},
mesh = {*Biofilms/drug effects ; *Mouthwashes/pharmacology ; *Dental Enamel/drug effects ; Animals ; Cattle ; Cross-Over Studies ; Humans ; Chlorhexidine/pharmacology ; *Cannabidiol/pharmacology ; Microscopy, Electron, Scanning ; Surface Properties ; Hardness ; },
abstract = {OBJECTIVES: This study evaluated the antibiofilm activity of experimental mouthwash containing different concentrations of cannabidiol (CBD) and the in situ effects on the physical and mechanical properties of dental enamel.
METHODS: Bovine enamel fragments (6 × 6 × 2 mm) were mounted in intraoral appliances worn by 14 participants in a crossover design. Mouthwash containing CBD (0%, 0.01%, 0.05%, and 0.1%) and 0.12% chlorhexidine (CHX) were tested. Each experimental phase lasted 7 days, separated by washout periods. One side of the appliance was exposed to a cariogenic challenge (20% sucrose) prior to treatment. Surface roughness (Ra), microhardness (%KHN), and color change (ΔE00) were measured before and after treatments. Biofilm and yeast counts (log10 CFU) were quantified, and enamel surfaces were analyzed by scanning electron microscopy. Data were analyzed using two-way ANOVA with Bonferroni post hoc tests and Kruskal-Wallis with Dunn's test (P < 0.05).
RESULTS: Sucrose did not significantly affect Ra (P > 0.05), although CBD 0.1% showed higher roughness than CHX under sucrose exposure (P < 0.05). No significant differences in %KHN were observed among treatments; however, sucrose reduced microhardness in the placebo and CBD 0.01% groups (P < 0.05). CHX exhibited the highest ΔE00 values (P < 0.05). Biofilm formation was similar among CHX, CBD 0.05%, and CBD 0.1% (P > 0.05), while CHX showed lower yeast counts than CBD 0.01% and CBD 0.1% (P < 0.05).
CONCLUSION: CBD 0.05% demonstrated potential for biofilm control without adversely affecting enamel properties.
CLINICAL RELEVANCE: This study provides evidence supporting a natural compound-based mouthwash as a clinically viable alternative to chlorhexidine, showing similar efficacy and no associated adverse effects under the conditions tested.},
}
MeSH Terms:
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*Biofilms/drug effects
*Mouthwashes/pharmacology
*Dental Enamel/drug effects
Animals
Cattle
Cross-Over Studies
Humans
Chlorhexidine/pharmacology
*Cannabidiol/pharmacology
Microscopy, Electron, Scanning
Surface Properties
Hardness
RevDate: 2026-07-01
CmpDate: 2026-07-01
Exploring the Link Between Bacterial Biofilm and Disease Severity in Cholesteatoma-Associated CSOM.
Medeniyet medical journal, 41(2):125-133.
OBJECTIVE: Chronic suppurative otitis media (CSOM) with cholesteatoma is a potentially dangerous condition that can lead to extracranial and intracranial complications. Bacteria associated with CSOM cholesteatoma frequently produce biofilms, which contribute to antibiotic resistance and accelerate disease progression.
METHODS: This cross-sectional study was conducted at the tertiary teaching hospital of Hasanuddin University, its affiliated hospitals, and the Hasanuddin University Medical Research Center (HUM-RC) between March 2024 and April 2025. Patients diagnosed with CSOM cholesteatoma who underwent mastoidectomy were enrolled. Bacterial isolates obtained from cholesteatoma tissue were evaluated for biofilm formation using crystal violet staining. Data were analyzed using SPSS software.
RESULTS: A total of 49 patients were included: 46.9% male and 53.1% female; age range 9-66 years. Of the bacterial isolates, 40 demonstrated biofilm formation. Pseudomonas aeruginosa was the most frequently identified species (42.5%), followed by 12 other species, all of which exhibited weak to moderate biofilm production. Based on the Telmesani grading system, 47% of patients presented with severe disease. However, the limited sample size restricted the ability to establish a statistically significant correlation between biofilm presence and clinical severity.
CONCLUSIONS: Biofilm formation was detected in the majority of bacterial isolates, with Pseudomonas aeruginosa emerging as the predominant species. Although nearly half of the patients presented with severe disease, most isolates demonstrated only weak to moderate biofilm production. The limited sample size restricted the ability to establish a statistically significant correlation between biofilm presence and clinical severity. Nevertheless, these findings highlight the importance of biofilm in the pathogenesis of CSOM and underscore the need for larger multicenter studies to clarify its role and inform the development of biofilm-targeted therapeutic strategies.
Additional Links: PMID-42381365
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PubMed:
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@article {pmid42381365,
year = {2026},
author = {Pandiangan, M and Gaffar, M and Djamin, R and Zainuddin, AA and Sjahril, R and Akil, MA},
title = {Exploring the Link Between Bacterial Biofilm and Disease Severity in Cholesteatoma-Associated CSOM.},
journal = {Medeniyet medical journal},
volume = {41},
number = {2},
pages = {125-133},
doi = {10.4274/MMJ.galenos.2026.88555},
pmid = {42381365},
issn = {2149-2042},
abstract = {OBJECTIVE: Chronic suppurative otitis media (CSOM) with cholesteatoma is a potentially dangerous condition that can lead to extracranial and intracranial complications. Bacteria associated with CSOM cholesteatoma frequently produce biofilms, which contribute to antibiotic resistance and accelerate disease progression.
METHODS: This cross-sectional study was conducted at the tertiary teaching hospital of Hasanuddin University, its affiliated hospitals, and the Hasanuddin University Medical Research Center (HUM-RC) between March 2024 and April 2025. Patients diagnosed with CSOM cholesteatoma who underwent mastoidectomy were enrolled. Bacterial isolates obtained from cholesteatoma tissue were evaluated for biofilm formation using crystal violet staining. Data were analyzed using SPSS software.
RESULTS: A total of 49 patients were included: 46.9% male and 53.1% female; age range 9-66 years. Of the bacterial isolates, 40 demonstrated biofilm formation. Pseudomonas aeruginosa was the most frequently identified species (42.5%), followed by 12 other species, all of which exhibited weak to moderate biofilm production. Based on the Telmesani grading system, 47% of patients presented with severe disease. However, the limited sample size restricted the ability to establish a statistically significant correlation between biofilm presence and clinical severity.
CONCLUSIONS: Biofilm formation was detected in the majority of bacterial isolates, with Pseudomonas aeruginosa emerging as the predominant species. Although nearly half of the patients presented with severe disease, most isolates demonstrated only weak to moderate biofilm production. The limited sample size restricted the ability to establish a statistically significant correlation between biofilm presence and clinical severity. Nevertheless, these findings highlight the importance of biofilm in the pathogenesis of CSOM and underscore the need for larger multicenter studies to clarify its role and inform the development of biofilm-targeted therapeutic strategies.},
}
RevDate: 2026-07-01
Mechanism-guided metal complex therapeutics for biofilm-driven wound infections and transdermal delivery.
Expert opinion on drug delivery [Epub ahead of print].
INTRODUCTION: Chronic wound infections remain a major healthcare challenge due to persistent polymicrobial biofilms and the increasing prevalence of antimicrobial resistance. Conventional antimicrobial therapies often fail to eradicate biofilms, highlighting the need for innovative therapeutic strategies. Metal complexes have emerged as promising candidates owing to their multitarget antimicrobial and antibiofilm activities and potential for localize wound treatment.
AREAS COVERED: This review examines the role of metal complexes in combating biofilm-associated wound infections. Their mechanisms of action, including membrane disruption, redox imbalance, quorum-sensing inhibition, metabolic interference, and biofilm matrix destabilization, are discussed. The review further explores the integration of metal complexes into advanced transdermal and wound patch platforms, including polymeric matrices, nanocomposite systems and stimuli-responsive delivery systems designed to enhance localized drug release, improve wound retention, and minimize systemic toxicity. Current preclinical and translational developments are also highlighted.
EXPERT OPINION: Metal-complex-based transdermal therapeutics represent a promising next-generation approach for managing chronic biofilm-mediated wound infections and overcoming antimicrobial resistance. However, successful clinical translation requires addressing challenges related to toxicity, formulation stability, manufacturing scalability, regulatory approval, and long-term safety. Future interdisciplinary efforts integrating microbiology, materials science, and clinical research will be essential to advance these technologies from laboratory to clinical practice.
Additional Links: PMID-42381547
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PubMed:
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@article {pmid42381547,
year = {2026},
author = {Maji, S and M N, S and Paramasivam, S and Rajaramon, S and Sujith, S and Solomon, AP and Pasupuleti, M},
title = {Mechanism-guided metal complex therapeutics for biofilm-driven wound infections and transdermal delivery.},
journal = {Expert opinion on drug delivery},
volume = {},
number = {},
pages = {},
doi = {10.1080/17425247.2026.2697993},
pmid = {42381547},
issn = {1744-7593},
abstract = {INTRODUCTION: Chronic wound infections remain a major healthcare challenge due to persistent polymicrobial biofilms and the increasing prevalence of antimicrobial resistance. Conventional antimicrobial therapies often fail to eradicate biofilms, highlighting the need for innovative therapeutic strategies. Metal complexes have emerged as promising candidates owing to their multitarget antimicrobial and antibiofilm activities and potential for localize wound treatment.
AREAS COVERED: This review examines the role of metal complexes in combating biofilm-associated wound infections. Their mechanisms of action, including membrane disruption, redox imbalance, quorum-sensing inhibition, metabolic interference, and biofilm matrix destabilization, are discussed. The review further explores the integration of metal complexes into advanced transdermal and wound patch platforms, including polymeric matrices, nanocomposite systems and stimuli-responsive delivery systems designed to enhance localized drug release, improve wound retention, and minimize systemic toxicity. Current preclinical and translational developments are also highlighted.
EXPERT OPINION: Metal-complex-based transdermal therapeutics represent a promising next-generation approach for managing chronic biofilm-mediated wound infections and overcoming antimicrobial resistance. However, successful clinical translation requires addressing challenges related to toxicity, formulation stability, manufacturing scalability, regulatory approval, and long-term safety. Future interdisciplinary efforts integrating microbiology, materials science, and clinical research will be essential to advance these technologies from laboratory to clinical practice.},
}
RevDate: 2026-07-01
Correction to ''Clinical Efficacy of Interventions Based on Professional Mechanical Plaque Removal in the Treatment of Dental Biofilm-Induced Gingivitis: A Systematic Review and Meta-Analysis''.
Additional Links: PMID-42381592
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@article {pmid42381592,
year = {2026},
author = {},
title = {Correction to ''Clinical Efficacy of Interventions Based on Professional Mechanical Plaque Removal in the Treatment of Dental Biofilm-Induced Gingivitis: A Systematic Review and Meta-Analysis''.},
journal = {Journal of clinical periodontology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jcpe.70149},
pmid = {42381592},
issn = {1600-051X},
}
RevDate: 2026-06-30
Alginate-based biofilm-assisted encapsulation of a Co-culture of Bifidobacterium longum DSM20219 and Bacillus subtilis SOM8 enhances resistance to gastrointestinal stress.
International journal of biological macromolecules, 373:153262 pii:S0141-8130(26)03202-2 [Epub ahead of print].
Oral probiotic formulations are increasingly explored for supporting gastrointestinal health, restoring gut microbiome balance, and providing non-invasive alternatives to injections or transplants. However, delivering oxygen-sensitive probiotics orally remains challenging because gastric acidity, bile salts, digestive enzymes, and aerobic storage can substantially reduce bacterial viability. Sodium alginate is widely used for probiotic encapsulation because it forms mild, cell-compatible hydrogel beads, but alginate-only matrices often provide limited protection for highly sensitive anaerobes due to their hydrated and permeable network structure. Here, we developed an alginate-based, biofilm-assisted encapsulation system for the co-culture and co-delivery of Bacillus subtilis SOM8 and Bifidobacterium longum DSM20219. This strategy enhanced probiotic tolerance to simulated gastric fluids (SGF) and simulated intestinal fluids (SIF), and extended shelf life under aerobic conditions. Biofilm-assisted encapsulation improved B. longum DSM20219 viability, maintaining survival above 7-log CFU/g after 2 h in SGF and SIF, representing an approximately 3-log improvement over alginate-only encapsulation. It also maintained over 6-log CFU/g after 28 days of aerobic storage. Imaging and time-resolved co-culture analyses suggested that the enhanced protection was associated with biofilm formation, cell aggregation, extracellular matrix development, and dynamic interspecies interactions within the alginate system. While further in vivo and omics-based validation will be required, these findings support biofilm-assisted co-encapsulation as a promising biologically integrated strategy for polymer-based probiotic delivery.
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@article {pmid42372892,
year = {2026},
author = {Zhao, Z and Kok, NWH and Wong, ASW and Nataño, JHJ and Nolan, LM and Loo, SCJ},
title = {Alginate-based biofilm-assisted encapsulation of a Co-culture of Bifidobacterium longum DSM20219 and Bacillus subtilis SOM8 enhances resistance to gastrointestinal stress.},
journal = {International journal of biological macromolecules},
volume = {373},
number = {},
pages = {153262},
doi = {10.1016/j.ijbiomac.2026.153262},
pmid = {42372892},
issn = {1879-0003},
abstract = {Oral probiotic formulations are increasingly explored for supporting gastrointestinal health, restoring gut microbiome balance, and providing non-invasive alternatives to injections or transplants. However, delivering oxygen-sensitive probiotics orally remains challenging because gastric acidity, bile salts, digestive enzymes, and aerobic storage can substantially reduce bacterial viability. Sodium alginate is widely used for probiotic encapsulation because it forms mild, cell-compatible hydrogel beads, but alginate-only matrices often provide limited protection for highly sensitive anaerobes due to their hydrated and permeable network structure. Here, we developed an alginate-based, biofilm-assisted encapsulation system for the co-culture and co-delivery of Bacillus subtilis SOM8 and Bifidobacterium longum DSM20219. This strategy enhanced probiotic tolerance to simulated gastric fluids (SGF) and simulated intestinal fluids (SIF), and extended shelf life under aerobic conditions. Biofilm-assisted encapsulation improved B. longum DSM20219 viability, maintaining survival above 7-log CFU/g after 2 h in SGF and SIF, representing an approximately 3-log improvement over alginate-only encapsulation. It also maintained over 6-log CFU/g after 28 days of aerobic storage. Imaging and time-resolved co-culture analyses suggested that the enhanced protection was associated with biofilm formation, cell aggregation, extracellular matrix development, and dynamic interspecies interactions within the alginate system. While further in vivo and omics-based validation will be required, these findings support biofilm-assisted co-encapsulation as a promising biologically integrated strategy for polymer-based probiotic delivery.},
}
RevDate: 2026-06-29
Engineering a capture-bioremediate-release microbial biofilm for simultaneous bioremediation of microplastics and adsorbed heavy metals.
Trends in biotechnology pii:S0167-7799(26)00244-1 [Epub ahead of print].
Microplastics (MPs) pose escalating environmental and human health risks, particularly when they adsorb heavy metals and form complex, co-contaminated pollutants. Furthermore, when MPs are removed and sent to landfills or incineration, the adsorbed heavy metals often persist and re-enter the environment. However, most existing remediation strategies remove only single pollutants, which fail to address complex pollution. In this research article, we engineered an environmental Pseudomonas aeruginosa strain with three programmable functions: (i) enhanced biofilm formation for efficient aggregation and capture of MPs, (ii) increased pyoverdine production for bioremediation of heavy metals (lead and cadmium) adsorbed on MPs, and (iii) subsequent arabinose-inducible biofilm dispersal to release decontaminated MPs for convenient recovery. Our proof of concept was validated in a pilot trial with polluted Hong Kong seawater, demonstrating efficient dual-pollutant removal in environmentally relevant conditions. Hence, our work highlights the promise of biotechnology in advancing multi-pollutant environmental remediation.
Additional Links: PMID-42373407
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PubMed:
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@article {pmid42373407,
year = {2026},
author = {Wei, W and Chua, SL},
title = {Engineering a capture-bioremediate-release microbial biofilm for simultaneous bioremediation of microplastics and adsorbed heavy metals.},
journal = {Trends in biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.tibtech.2026.06.004},
pmid = {42373407},
issn = {1879-3096},
abstract = {Microplastics (MPs) pose escalating environmental and human health risks, particularly when they adsorb heavy metals and form complex, co-contaminated pollutants. Furthermore, when MPs are removed and sent to landfills or incineration, the adsorbed heavy metals often persist and re-enter the environment. However, most existing remediation strategies remove only single pollutants, which fail to address complex pollution. In this research article, we engineered an environmental Pseudomonas aeruginosa strain with three programmable functions: (i) enhanced biofilm formation for efficient aggregation and capture of MPs, (ii) increased pyoverdine production for bioremediation of heavy metals (lead and cadmium) adsorbed on MPs, and (iii) subsequent arabinose-inducible biofilm dispersal to release decontaminated MPs for convenient recovery. Our proof of concept was validated in a pilot trial with polluted Hong Kong seawater, demonstrating efficient dual-pollutant removal in environmentally relevant conditions. Hence, our work highlights the promise of biotechnology in advancing multi-pollutant environmental remediation.},
}
RevDate: 2026-06-29
Antibacterial and anti-biofilm mechanisms of 1,8-cineole against colistin-resistant Acinetobacter baumannii: an integrated in vitro, gene expression, and in silico study.
Scientific reports pii:10.1038/s41598-026-60309-z [Epub ahead of print].
The rise of colistin-resistant Acinetobacter baumannii (ColR Ab) poses a major clinical challenge, underscoring the urgent need for alternative antimicrobial agents. This study evaluated the antibacterial and anti-biofilm mechanisms of 1,8-cineole against ColR Ab using in vitro, transcriptional, and in silico approaches. Minimum inhibitory concentrations (MICs) and anti-biofilm activities were determined against three ColR Ab isolates. Membrane integrity was assessed via protein and nucleic acid leakage assays. Scanning electron microscopy (SEM) revealed bacterial morphology and biofilm structure, and expression of biofilm-associated genes was analyzed by qRT-PCR. Additionally, molecular docking analysis was employed to evaluate the binding affinity of 1,8-cineole against key target proteins of A. baumannii. The inhibition zone in the disk diffusion method and MIC were 10.3 ± 0.8 mm and 3.6 mg/mL, respectively. 1,8-cineole also caused significant protein and nucleic acid leakage and, at 4× MIC, significantly disrupted the mature biofilm structure. SEM confirmed bacterial cell membrane rupture, intracellular content leakage, and ultrastructural damage following treatment. qRT-PCR validation demonstrated that 1,8-cineole significantly downregulated the expression of the bfmR, bap, csuE, ompA, and pgaB, while abaI expression was not significantly affected. Molecular docking simulations predicted favorable binding of 1,8-cineole to quorum-sensing regulators AbaR and LasR. 1,8-cineole exhibits significant bactericidal and anti-biofilm activity against ColR Ab. Its mechanism of action may involve disruption of cell membrane integrity and potential interference with bacterial key quorum-sensing regulators. This study provides a theoretical basis for developing 1,8-cineole as a potential therapeutic strategy against ColR Ab infections.
Additional Links: PMID-42373704
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PubMed:
Citation:
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@article {pmid42373704,
year = {2026},
author = {Kashi, M and Alshemri, ABS and Alimardan, Z and Arjomandzadegan, M and Hariri, Y and Chegini, Z and Shariati, A},
title = {Antibacterial and anti-biofilm mechanisms of 1,8-cineole against colistin-resistant Acinetobacter baumannii: an integrated in vitro, gene expression, and in silico study.},
journal = {Scientific reports},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41598-026-60309-z},
pmid = {42373704},
issn = {2045-2322},
abstract = {The rise of colistin-resistant Acinetobacter baumannii (ColR Ab) poses a major clinical challenge, underscoring the urgent need for alternative antimicrobial agents. This study evaluated the antibacterial and anti-biofilm mechanisms of 1,8-cineole against ColR Ab using in vitro, transcriptional, and in silico approaches. Minimum inhibitory concentrations (MICs) and anti-biofilm activities were determined against three ColR Ab isolates. Membrane integrity was assessed via protein and nucleic acid leakage assays. Scanning electron microscopy (SEM) revealed bacterial morphology and biofilm structure, and expression of biofilm-associated genes was analyzed by qRT-PCR. Additionally, molecular docking analysis was employed to evaluate the binding affinity of 1,8-cineole against key target proteins of A. baumannii. The inhibition zone in the disk diffusion method and MIC were 10.3 ± 0.8 mm and 3.6 mg/mL, respectively. 1,8-cineole also caused significant protein and nucleic acid leakage and, at 4× MIC, significantly disrupted the mature biofilm structure. SEM confirmed bacterial cell membrane rupture, intracellular content leakage, and ultrastructural damage following treatment. qRT-PCR validation demonstrated that 1,8-cineole significantly downregulated the expression of the bfmR, bap, csuE, ompA, and pgaB, while abaI expression was not significantly affected. Molecular docking simulations predicted favorable binding of 1,8-cineole to quorum-sensing regulators AbaR and LasR. 1,8-cineole exhibits significant bactericidal and anti-biofilm activity against ColR Ab. Its mechanism of action may involve disruption of cell membrane integrity and potential interference with bacterial key quorum-sensing regulators. This study provides a theoretical basis for developing 1,8-cineole as a potential therapeutic strategy against ColR Ab infections.},
}
RevDate: 2026-06-30
Editorial Expression of Concern: Hindering the biofilm of microbial pathogens and cancer cell lines development using silver nanoparticles synthesized by epidermal mucus proteins from Clarias gariepinus.
BMC biotechnology, 26(1):.
Additional Links: PMID-42374468
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@article {pmid42374468,
year = {2026},
author = {Alabssawy, AN and Abu-Elghait, M and Azab, AM and Khalaf-Allah, HMM and Ashry, AS and Ali, AOM and Sabra, AAA and Salem, SS},
title = {Editorial Expression of Concern: Hindering the biofilm of microbial pathogens and cancer cell lines development using silver nanoparticles synthesized by epidermal mucus proteins from Clarias gariepinus.},
journal = {BMC biotechnology},
volume = {26},
number = {1},
pages = {},
pmid = {42374468},
issn = {1472-6750},
}
RevDate: 2026-06-30
In situ glycosylation-directed H-aggregation of Type I photosensitizers for synergistic biofilm eradication and promoting diabetic wound healing.
Chemical science [Epub ahead of print].
Biofilm-associated diabetic wound infections pose a major therapeutic challenge. Although photodynamic therapy (PDT) offers an alternative antibacterial strategy, conventional photosensitizers are often limited by inadequate biofilm penetration and poor activity under hypoxic conditions. In this study, we report glycosylated photosensitizers (NBS-Gal and NBS-Lac) that spontaneously form H-aggregates in aqueous media via π-stacking. This self-assembly integrates molecular function with nanostructure without requiring auxiliary components and enables robust Type I photodynamic activity. Notably, NBS-Lac exhibits superior H-aggregation, resulting in 2.2-fold and 1.8-fold higher O2 [˙-] generation (after 4 min irradiation) than NBS-NH2 and NBS-Gal, respectively. The glycosyl moieties enable targeted bacterial recognition through carbohydrate-lectin interactions, while the positive charge on NBS facilitates biofilm penetration via electrostatic interactions. NBS-Lac achieves 100% bactericidal efficacy against P. aeruginosa, along with high biofilm inhibition (∼87%) and eradication (∼80%). In a murine diabetic wound model, NBS-Lac mediates complete healing (100%) under light irradiation, significantly outperforming the controls. This work establishes carbohydrate-directed self-assembly as a novel paradigm for designing targeted, hypoxia-tolerant Type I PDT agents.
Additional Links: PMID-42375183
PubMed:
Citation:
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@article {pmid42375183,
year = {2026},
author = {Xi, D and Jiang, W and Li, M and Guo, J and Wang, P and Yin, F and Fan, X and Wang, KR and Sun, W and Peng, X},
title = {In situ glycosylation-directed H-aggregation of Type I photosensitizers for synergistic biofilm eradication and promoting diabetic wound healing.},
journal = {Chemical science},
volume = {},
number = {},
pages = {},
pmid = {42375183},
issn = {2041-6520},
abstract = {Biofilm-associated diabetic wound infections pose a major therapeutic challenge. Although photodynamic therapy (PDT) offers an alternative antibacterial strategy, conventional photosensitizers are often limited by inadequate biofilm penetration and poor activity under hypoxic conditions. In this study, we report glycosylated photosensitizers (NBS-Gal and NBS-Lac) that spontaneously form H-aggregates in aqueous media via π-stacking. This self-assembly integrates molecular function with nanostructure without requiring auxiliary components and enables robust Type I photodynamic activity. Notably, NBS-Lac exhibits superior H-aggregation, resulting in 2.2-fold and 1.8-fold higher O2 [˙-] generation (after 4 min irradiation) than NBS-NH2 and NBS-Gal, respectively. The glycosyl moieties enable targeted bacterial recognition through carbohydrate-lectin interactions, while the positive charge on NBS facilitates biofilm penetration via electrostatic interactions. NBS-Lac achieves 100% bactericidal efficacy against P. aeruginosa, along with high biofilm inhibition (∼87%) and eradication (∼80%). In a murine diabetic wound model, NBS-Lac mediates complete healing (100%) under light irradiation, significantly outperforming the controls. This work establishes carbohydrate-directed self-assembly as a novel paradigm for designing targeted, hypoxia-tolerant Type I PDT agents.},
}
RevDate: 2026-06-30
CmpDate: 2026-06-30
Multidrug resistance and biofilm-forming ability of Escherichia coli isolated from free-range chicken meat in restaurants in Petrolina, Pernambuco, Brazil.
Open veterinary journal, 16(1):616-625.
BACKGROUND: Although free-range chicken meat is widely consumed in Brazil, it may pose a public health risk due to contamination with pathogenic and antimicrobial-resistant bacteria, such as Escherichia coli (EC).
AIM: This study aimed to investigate the occurrence of EC, antimicrobial resistance, and biofilm formation in free-range chicken meat samples collected from restaurants in Petrolina, Pernambuco, Brazil.
METHODS: Microbiological and molecular methods were used to analyze 40 samples collected from eight restaurants to detect EC, evaluate antimicrobial resistance profiles, assess biofilm formation, and identify the presence of resistance genes.
RESULTS: The overall frequency of EC infection was 57.5%. All bacterial strains (100%) were resistant to at least one antimicrobial agent, and 78.2% (18/23) were classified as MDR, showing resistance to three or more classes of antibiotics, with the highest rates observed for ciprofloxacin and tetracycline. Among the detected resistance genes, the blaTEM gene had the highest prevalence (17.4%), followed by blaCTX-M1 (4.3%), while tetA and qnrS were not detected. A discrepancy was observed between high phenotypic resistance and low detection of resistance genes, suggesting the involvement of other mechanisms. In addition, 95.5% of the strains were classified as biofilm producers, although most exhibited weak biofilm formation.
CONCLUSION: This study confirms the presence of multidrug-resistant EC strains in food served at restaurants, highlighting the risk of transmission of resistant bacteria to humans through the consumption of contaminated meat and reinforcing the need for continuous monitoring of food safety.
Additional Links: PMID-42375257
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Citation:
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@article {pmid42375257,
year = {2026},
author = {do Carmo Resende Martins, CM and de Sá, DRC and Martins, MG and de Sousa, MAS and da Silva Bezerra, AD and de Souza, MR and Araújo, BN and Rosa, DS and Gouveia, GV and da Costa, MM and de Souza Rodrigues, RT},
title = {Multidrug resistance and biofilm-forming ability of Escherichia coli isolated from free-range chicken meat in restaurants in Petrolina, Pernambuco, Brazil.},
journal = {Open veterinary journal},
volume = {16},
number = {1},
pages = {616-625},
pmid = {42375257},
issn = {2218-6050},
mesh = {Animals ; Brazil ; *Biofilms/growth & development ; Chickens ; *Escherichia coli/drug effects/physiology/isolation & purification/genetics ; *Drug Resistance, Multiple, Bacterial/genetics ; *Meat/microbiology ; *Anti-Bacterial Agents/pharmacology ; Restaurants ; Food Microbiology ; Microbial Sensitivity Tests/veterinary ; },
abstract = {BACKGROUND: Although free-range chicken meat is widely consumed in Brazil, it may pose a public health risk due to contamination with pathogenic and antimicrobial-resistant bacteria, such as Escherichia coli (EC).
AIM: This study aimed to investigate the occurrence of EC, antimicrobial resistance, and biofilm formation in free-range chicken meat samples collected from restaurants in Petrolina, Pernambuco, Brazil.
METHODS: Microbiological and molecular methods were used to analyze 40 samples collected from eight restaurants to detect EC, evaluate antimicrobial resistance profiles, assess biofilm formation, and identify the presence of resistance genes.
RESULTS: The overall frequency of EC infection was 57.5%. All bacterial strains (100%) were resistant to at least one antimicrobial agent, and 78.2% (18/23) were classified as MDR, showing resistance to three or more classes of antibiotics, with the highest rates observed for ciprofloxacin and tetracycline. Among the detected resistance genes, the blaTEM gene had the highest prevalence (17.4%), followed by blaCTX-M1 (4.3%), while tetA and qnrS were not detected. A discrepancy was observed between high phenotypic resistance and low detection of resistance genes, suggesting the involvement of other mechanisms. In addition, 95.5% of the strains were classified as biofilm producers, although most exhibited weak biofilm formation.
CONCLUSION: This study confirms the presence of multidrug-resistant EC strains in food served at restaurants, highlighting the risk of transmission of resistant bacteria to humans through the consumption of contaminated meat and reinforcing the need for continuous monitoring of food safety.},
}
MeSH Terms:
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Animals
Brazil
*Biofilms/growth & development
Chickens
*Escherichia coli/drug effects/physiology/isolation & purification/genetics
*Drug Resistance, Multiple, Bacterial/genetics
*Meat/microbiology
*Anti-Bacterial Agents/pharmacology
Restaurants
Food Microbiology
Microbial Sensitivity Tests/veterinary
RevDate: 2026-06-30
CmpDate: 2026-06-30
Surfactant-Engineered Niosomal Antibiotic Systems for Biofilm-Associated Infections: Design Principles and Translational Perspectives.
International journal of nanomedicine, 21:607567.
Persistent microbial biofilm infections remain a major obstacle to effective antimicrobial therapy due to restricted drug diffusion, metabolic heterogeneity, and the presence of tolerant bacterial subpopulations. In device-associated infections, biofilms substantially reduce antibiotic efficacy and contribute to chronic relapse despite adequate systemic exposure. Although nanocarrier-based delivery systems have been widely investigated, many formulations remain empirically developed with insufficient consideration of biofilm-specific physicochemical and biological barriers. This review examines surfactant-engineered niosomal antibiotic systems from a rational design perspective. Key formulation parameters, including surfactant type, hydrophile-lipophile balance (HLB), cholesterol content, surface charge, and microenvironment-responsive behavior, critically influence bilayer rigidity, permeability, encapsulation efficiency, intrabiofilm transport, and release kinetics. In particular, electrostatic interactions with the negatively charged extracellular polymeric substance (EPS) matrix and pH-responsive destabilization strategies are discussed as important determinants of localized antibiotic delivery within heterogeneous biofilm environments. Despite promising antibiofilm activity in vitro, translational progress remains limited by variability in formulation characterization, insufficient in vivo validation, and incomplete alignment between carrier responsiveness and biofilm microenvironmental conditions. By integrating insights from pharmaceutics, materials science, and microbial pathophysiology, this review proposes a structured framework for the rational design of surfactant-engineered niosomes and highlights key considerations for advancing antibiofilm nanomedicine.
Additional Links: PMID-42376636
PubMed:
Citation:
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@article {pmid42376636,
year = {2026},
author = {Rahma, S and Amalia, E and Kusuma, SAF},
title = {Surfactant-Engineered Niosomal Antibiotic Systems for Biofilm-Associated Infections: Design Principles and Translational Perspectives.},
journal = {International journal of nanomedicine},
volume = {21},
number = {},
pages = {607567},
pmid = {42376636},
issn = {1178-2013},
mesh = {*Biofilms/drug effects ; *Anti-Bacterial Agents/chemistry/administration & dosage/pharmacology/pharmacokinetics ; *Surface-Active Agents/chemistry ; *Liposomes/chemistry ; Humans ; Animals ; },
abstract = {Persistent microbial biofilm infections remain a major obstacle to effective antimicrobial therapy due to restricted drug diffusion, metabolic heterogeneity, and the presence of tolerant bacterial subpopulations. In device-associated infections, biofilms substantially reduce antibiotic efficacy and contribute to chronic relapse despite adequate systemic exposure. Although nanocarrier-based delivery systems have been widely investigated, many formulations remain empirically developed with insufficient consideration of biofilm-specific physicochemical and biological barriers. This review examines surfactant-engineered niosomal antibiotic systems from a rational design perspective. Key formulation parameters, including surfactant type, hydrophile-lipophile balance (HLB), cholesterol content, surface charge, and microenvironment-responsive behavior, critically influence bilayer rigidity, permeability, encapsulation efficiency, intrabiofilm transport, and release kinetics. In particular, electrostatic interactions with the negatively charged extracellular polymeric substance (EPS) matrix and pH-responsive destabilization strategies are discussed as important determinants of localized antibiotic delivery within heterogeneous biofilm environments. Despite promising antibiofilm activity in vitro, translational progress remains limited by variability in formulation characterization, insufficient in vivo validation, and incomplete alignment between carrier responsiveness and biofilm microenvironmental conditions. By integrating insights from pharmaceutics, materials science, and microbial pathophysiology, this review proposes a structured framework for the rational design of surfactant-engineered niosomes and highlights key considerations for advancing antibiofilm nanomedicine.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects
*Anti-Bacterial Agents/chemistry/administration & dosage/pharmacology/pharmacokinetics
*Surface-Active Agents/chemistry
*Liposomes/chemistry
Humans
Animals
RevDate: 2026-06-30
Impact of the invasive diatom species Cymbella janischii on riverine microbial biofilm communities and a potential role of bacterially produced zeatin.
Journal of phycology [Epub ahead of print].
The diatom Cymbella janischii is an invasive species in Japan, causing nuisance blooms by forming thick mats in rivers. To date, there are no documented studies on the microbiome associations in C. janischii mats or the processes that drive bloom formation. This study used metabarcoding of diatoms, bacteria, and fungi to identify key species and assess the effects of C. janischii blooms on the benthic microbial communities. C. janischii blooms reduced diatom and bacterial species diversity, while fungal diversity remained stable. In addition, the diatom Nitzschia paleacea and the bacterium Flavobacterium sp. were observed to co-occur and vary in abundance, indicating a possible ecological link that may affect mat structure or function. Metagenomic predictions of bacterial functions showed that compared to benthic stones without visible C. janischii mats, mat-associated bacteria had enriched pathways related to the metabolism of carbohydrates, nucleotides, and amino acids, along with zeatin biosynthesis. Zeatin is a cytokinin phytohormone that stimulates plant growth and development. In vitro exposure of C. janischii to varying zeatin concentrations confirmed its growth-promoting effects, inducing cell proliferation and stalk formation. This study shows that zeatin stimulates the growth of C. janischii. The findings of this study provide new insights into microbiome diversity, identifying key taxa associated with C. janischii mats to help better understand bloom formation.
Additional Links: PMID-42376710
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PubMed:
Citation:
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@article {pmid42376710,
year = {2026},
author = {Arguelles, EDLR and Mugikura, K and Sato, S},
title = {Impact of the invasive diatom species Cymbella janischii on riverine microbial biofilm communities and a potential role of bacterially produced zeatin.},
journal = {Journal of phycology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jpy.70195},
pmid = {42376710},
issn = {1529-8817},
support = {21A402//Japan Society for the Promotion of Science/ ; 23K05398//Japan Society for the Promotion of Science/ ; 26K01814//Japan Society for the Promotion of Science/ ; //Ministry of Education, Culture, Sports, Science and Technology/ ; },
abstract = {The diatom Cymbella janischii is an invasive species in Japan, causing nuisance blooms by forming thick mats in rivers. To date, there are no documented studies on the microbiome associations in C. janischii mats or the processes that drive bloom formation. This study used metabarcoding of diatoms, bacteria, and fungi to identify key species and assess the effects of C. janischii blooms on the benthic microbial communities. C. janischii blooms reduced diatom and bacterial species diversity, while fungal diversity remained stable. In addition, the diatom Nitzschia paleacea and the bacterium Flavobacterium sp. were observed to co-occur and vary in abundance, indicating a possible ecological link that may affect mat structure or function. Metagenomic predictions of bacterial functions showed that compared to benthic stones without visible C. janischii mats, mat-associated bacteria had enriched pathways related to the metabolism of carbohydrates, nucleotides, and amino acids, along with zeatin biosynthesis. Zeatin is a cytokinin phytohormone that stimulates plant growth and development. In vitro exposure of C. janischii to varying zeatin concentrations confirmed its growth-promoting effects, inducing cell proliferation and stalk formation. This study shows that zeatin stimulates the growth of C. janischii. The findings of this study provide new insights into microbiome diversity, identifying key taxa associated with C. janischii mats to help better understand bloom formation.},
}
RevDate: 2026-06-30
Effects of cinnamon essential oil on quorum-sensing-associated virulence and biofilm formation in Pseudomonas tolaasii.
Letters in applied microbiology pii:8722222 [Epub ahead of print].
Cinnamon essential oil (CEO), one of volatile plant compounds, exhibits potent inhibitory effects on bacterial growth. Pseudomonas tolaasii (P. tolaasii) is the primary spoilage bacterium that causes the decay of Agaricus bisporus. This study investigated the effects of cinnamon essential oil (CEO) on quorum sensing (QS) and biofilm formation in Pseudomonas tolaasii. Whole-genome analysis revealed 102 QS-related genes and their association with 10 virulence protein clusters. AHL signaling molecules (C4-HSL, C6-HSL, C8-HSL, and 3-Oxo-C10-HSL) were identified using biosensor methods and LC-MS/MS. CEO significantly inhibited virulence factor secretion, including protease, elastase, and rhamnolipid. It also reduced swarming and swimming motility by 77.21% and 71.38%, respectively, and effectively suppressed biofilm formation by lowering bacterial viscosity and surface hydrophobicity. At a concentration of 0.4 μL/mL, CEO reduced biofilm formation by 40.89% within 24 h, as measured by the crystal violet method. Microscopic and FTIR analysis confirmed CEO's effect on biofilm and extracellular polymer secretion. Thus, it may serve as a novel type of anti-biofilm agent.
Additional Links: PMID-42377901
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PubMed:
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@article {pmid42377901,
year = {2026},
author = {Luan, X and Song, L and Chen, X and Feng, Y and Zhang, H and Han, X and Liu, Z},
title = {Effects of cinnamon essential oil on quorum-sensing-associated virulence and biofilm formation in Pseudomonas tolaasii.},
journal = {Letters in applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/lambio/ovag056},
pmid = {42377901},
issn = {1472-765X},
abstract = {Cinnamon essential oil (CEO), one of volatile plant compounds, exhibits potent inhibitory effects on bacterial growth. Pseudomonas tolaasii (P. tolaasii) is the primary spoilage bacterium that causes the decay of Agaricus bisporus. This study investigated the effects of cinnamon essential oil (CEO) on quorum sensing (QS) and biofilm formation in Pseudomonas tolaasii. Whole-genome analysis revealed 102 QS-related genes and their association with 10 virulence protein clusters. AHL signaling molecules (C4-HSL, C6-HSL, C8-HSL, and 3-Oxo-C10-HSL) were identified using biosensor methods and LC-MS/MS. CEO significantly inhibited virulence factor secretion, including protease, elastase, and rhamnolipid. It also reduced swarming and swimming motility by 77.21% and 71.38%, respectively, and effectively suppressed biofilm formation by lowering bacterial viscosity and surface hydrophobicity. At a concentration of 0.4 μL/mL, CEO reduced biofilm formation by 40.89% within 24 h, as measured by the crystal violet method. Microscopic and FTIR analysis confirmed CEO's effect on biofilm and extracellular polymer secretion. Thus, it may serve as a novel type of anti-biofilm agent.},
}
RevDate: 2026-06-30
Feeding the invaders: How metabolic imbalance shapes infection and biofilm development.
FEMS microbiology reviews pii:8722208 [Epub ahead of print].
Infectious and metabolic disorders have risen sharply and pose a significant threat to human populations worldwide. Despite being deemed unrelated, mounting evidence indicates that metabolic disorders markedly heightened both the likelihood and severity of infectious disease. The mechanism underlying this association is only beginning to be appreciated and involves a complex interaction between altered metabolic state, pathogen virulence mechanisms, and immune effector pathways. Here, we highlight that a dysregulated metabolic environment disrupts homeostasis, creating a nutrient-rich, immunocompromised milieu that promotes bacterial survival and replication in the host. Metabolic dysfunction is also discussed as a factor that promotes bacterial persistence by altering reactive oxygen species production and inducing tissue hypoxia, conditions that favor biofilm growth. We also examine how bacteria directly exploit nutrient surplus in metabolic diseases to boost their virulence programs and biofilm formation. Moreover, given the ever-increasing problem of antibiotic resistance, we discuss how metabolic diseases contribute to this challenge. Collectively, uncovering how metabolic disorders increase chronic or recurrent infections can guide the development of effective treatment strategies.
Additional Links: PMID-42377912
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PubMed:
Citation:
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@article {pmid42377912,
year = {2026},
author = {Mahajan, S and MacDowell, S and Mitchem, C and Alexander, E and Wozniak, DJ},
title = {Feeding the invaders: How metabolic imbalance shapes infection and biofilm development.},
journal = {FEMS microbiology reviews},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsre/fuag029},
pmid = {42377912},
issn = {1574-6976},
abstract = {Infectious and metabolic disorders have risen sharply and pose a significant threat to human populations worldwide. Despite being deemed unrelated, mounting evidence indicates that metabolic disorders markedly heightened both the likelihood and severity of infectious disease. The mechanism underlying this association is only beginning to be appreciated and involves a complex interaction between altered metabolic state, pathogen virulence mechanisms, and immune effector pathways. Here, we highlight that a dysregulated metabolic environment disrupts homeostasis, creating a nutrient-rich, immunocompromised milieu that promotes bacterial survival and replication in the host. Metabolic dysfunction is also discussed as a factor that promotes bacterial persistence by altering reactive oxygen species production and inducing tissue hypoxia, conditions that favor biofilm growth. We also examine how bacteria directly exploit nutrient surplus in metabolic diseases to boost their virulence programs and biofilm formation. Moreover, given the ever-increasing problem of antibiotic resistance, we discuss how metabolic diseases contribute to this challenge. Collectively, uncovering how metabolic disorders increase chronic or recurrent infections can guide the development of effective treatment strategies.},
}
RevDate: 2026-06-30
CmpDate: 2026-06-30
Disruption of efflux activity reduces biofilm formation through multiple pathways.
Microbiology (Reading, England), 172(6):.
Free-swimming bacteria must undergo large-scale changes in gene expression to form structured, aggregated biofilm communities. These regulatory changes are susceptible to environmental stimuli such as exposure to antimicrobials, which can affect adhesion, biofilm matrix production, pathogenicity and multidrug susceptibility. Previously, we found that genetic or chemical inactivation of efflux activity in Escherichia coli and Salmonella Typhimurium disrupts biofilm formation with a wide range of pathways sensitive to efflux inhibition, including reduced expression of csgD, a major regulator of biofilm matrix production. How the regulatory networks controlling efflux activity and biofilm formation overlap and how perturbing efflux impacts biofilm formation is still unclear. To address this, we used a combination of directed evolution experiments and large-scale functional genomics screens (TraDIS-Xpress) to identify the genes and pathways affecting efflux activity and biofilm formation in Salmonella enterica serovar Typhimurium and E. coli. This work describes the landscape of pathways linking efflux activity and biofilm formation. Whilst no singular gene or pathway was found to control the link between the two phenotypes, we propose changes in membrane potential following efflux inactivation are sensed through multiple response regulators that each in turn contribute to repression of biofilm development. These include the two-component signal transduction system EnvZ-OmpR and AraC/XylS family transcriptional regulators, RamA and MarA, which have extensive overlapping regulons and demonstrate high degrees of functional redundancy. This work deepens our understanding of the regulatory networks governing efflux activity and biofilm formation in Enterobacteriaceae and highlights the level of overlapping regulation and functional redundancy between them.
Additional Links: PMID-42378026
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PubMed:
Citation:
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@article {pmid42378026,
year = {2026},
author = {Holden, ER and Sims, L and Orchard, K and Trampari, E and Charles, IG and Webber, MA},
title = {Disruption of efflux activity reduces biofilm formation through multiple pathways.},
journal = {Microbiology (Reading, England)},
volume = {172},
number = {6},
pages = {},
doi = {10.1099/mic.0.001734},
pmid = {42378026},
issn = {1465-2080},
mesh = {*Biofilms/growth & development ; *Salmonella typhimurium/genetics/metabolism/physiology ; *Escherichia coli/genetics/metabolism/physiology ; Gene Expression Regulation, Bacterial ; Escherichia coli Proteins/genetics/metabolism ; Trans-Activators/genetics/metabolism ; Bacterial Proteins/genetics/metabolism ; Membrane Transport Proteins/genetics/metabolism ; Directed Molecular Evolution ; },
abstract = {Free-swimming bacteria must undergo large-scale changes in gene expression to form structured, aggregated biofilm communities. These regulatory changes are susceptible to environmental stimuli such as exposure to antimicrobials, which can affect adhesion, biofilm matrix production, pathogenicity and multidrug susceptibility. Previously, we found that genetic or chemical inactivation of efflux activity in Escherichia coli and Salmonella Typhimurium disrupts biofilm formation with a wide range of pathways sensitive to efflux inhibition, including reduced expression of csgD, a major regulator of biofilm matrix production. How the regulatory networks controlling efflux activity and biofilm formation overlap and how perturbing efflux impacts biofilm formation is still unclear. To address this, we used a combination of directed evolution experiments and large-scale functional genomics screens (TraDIS-Xpress) to identify the genes and pathways affecting efflux activity and biofilm formation in Salmonella enterica serovar Typhimurium and E. coli. This work describes the landscape of pathways linking efflux activity and biofilm formation. Whilst no singular gene or pathway was found to control the link between the two phenotypes, we propose changes in membrane potential following efflux inactivation are sensed through multiple response regulators that each in turn contribute to repression of biofilm development. These include the two-component signal transduction system EnvZ-OmpR and AraC/XylS family transcriptional regulators, RamA and MarA, which have extensive overlapping regulons and demonstrate high degrees of functional redundancy. This work deepens our understanding of the regulatory networks governing efflux activity and biofilm formation in Enterobacteriaceae and highlights the level of overlapping regulation and functional redundancy between them.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Salmonella typhimurium/genetics/metabolism/physiology
*Escherichia coli/genetics/metabolism/physiology
Gene Expression Regulation, Bacterial
Escherichia coli Proteins/genetics/metabolism
Trans-Activators/genetics/metabolism
Bacterial Proteins/genetics/metabolism
Membrane Transport Proteins/genetics/metabolism
Directed Molecular Evolution
RevDate: 2026-06-30
Electrophoretic deposition-assisted layer-by-layer construction of carbon nanotube-MnO2-based hybrid biofilm for supercapacitive microbial fuel cells.
Colloids and surfaces. B, Biointerfaces, 267:115945 pii:S0927-7765(26)00533-3 [Epub ahead of print].
The exploitation of hybrid biofilm with alternating functional layer represents a promising way to upgrade the performance of supercapacitive microbial fuel cells (SC-MFCs). However, the popularization of this special hybrid biofilm requires a convenient and scalable construction strategy. Herein, the electrophoretic deposition-assisted layer-by-layer construction strategy has been developed to successively deposit carbon nanotube-manganese dioxide nanocomposite (C-M) and bacterial cells for the formation of hybrid biofilm. When using in SC-MFCs, the hybrid biofilm with two repetitive C-M/bacteria bilayers displayed the optimal performance due to the improvement of functional components without the sacrifice of electron transfer efficiency and bacterial metabolic activity. Moreover, the intercalation of capacitive and conductive C-M layer between bacteria layers enlarges their interaction interface and builds an accelerated electron transfer network inside the developed hybrid biofilm. As a result, the developed hybrid biofilm displayed enhanced capacitance, improved electricity generation capacity and promoted self-charge-discharge behavior compared to the counterpart biofilms. This work demonstrates the potential of electrophoretic deposition technology for the alternative construction of different functional layers in hybrid biofilm, which will be attractive for SC-MFCs and other microbial electrochemical systems.
Additional Links: PMID-42378773
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PubMed:
Citation:
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@article {pmid42378773,
year = {2026},
author = {Chen, S and Li, Y and Wang, S and Peng, X and Sun, J and Zhang, L and Song, RB and Li, Z},
title = {Electrophoretic deposition-assisted layer-by-layer construction of carbon nanotube-MnO2-based hybrid biofilm for supercapacitive microbial fuel cells.},
journal = {Colloids and surfaces. B, Biointerfaces},
volume = {267},
number = {},
pages = {115945},
doi = {10.1016/j.colsurfb.2026.115945},
pmid = {42378773},
issn = {1873-4367},
abstract = {The exploitation of hybrid biofilm with alternating functional layer represents a promising way to upgrade the performance of supercapacitive microbial fuel cells (SC-MFCs). However, the popularization of this special hybrid biofilm requires a convenient and scalable construction strategy. Herein, the electrophoretic deposition-assisted layer-by-layer construction strategy has been developed to successively deposit carbon nanotube-manganese dioxide nanocomposite (C-M) and bacterial cells for the formation of hybrid biofilm. When using in SC-MFCs, the hybrid biofilm with two repetitive C-M/bacteria bilayers displayed the optimal performance due to the improvement of functional components without the sacrifice of electron transfer efficiency and bacterial metabolic activity. Moreover, the intercalation of capacitive and conductive C-M layer between bacteria layers enlarges their interaction interface and builds an accelerated electron transfer network inside the developed hybrid biofilm. As a result, the developed hybrid biofilm displayed enhanced capacitance, improved electricity generation capacity and promoted self-charge-discharge behavior compared to the counterpart biofilms. This work demonstrates the potential of electrophoretic deposition technology for the alternative construction of different functional layers in hybrid biofilm, which will be attractive for SC-MFCs and other microbial electrochemical systems.},
}
RevDate: 2026-06-27
CmpDate: 2026-06-27
Virulence modulation and biofilm inhibition of Streptococcus pyogenes by metabolites from endophytic fungi associated with Vanda tessellata.
Molecular biology reports, 53(1):.
BACKGROUND: Endophytic fungi represent a valuable source of bioactive metabolites with potential applications in addressing antimicrobial resistance. Biofilm formation by Streptococcus pyogenes contributes to antibiotic tolerance and persistent infections, highlighting the need for alternative anti-virulence strategies.
METHODS AND RESULTS: In this study, endophytic fungi associated with the medicinal orchid Vanda tessellata were isolated and evaluated for their antimicrobial and antibiofilm activity against S. pyogenes using in vitro assays, microscopy, and viability analysis. Among the isolates, Nodulisporium verrucosum exhibited the strongest antibiofilm activity, achieving 90% inhibition at its minimum biofilm inhibitory concentration (MBIC) of 0.5 mg/mL, without affecting bacterial viability. Bioactivity-guided HR-LCMS analysis of the active extract revealed nine putative metabolites. Further computational ADMET profiling and molecular docking analyses identified tributyrin as a promising anti-virulence candidate, showing favorable pharmacokinetic properties and stable interactions with key biofilm-associated regulatory proteins of S. pyogenes. In addition, tributyrin demonstrated low cytotoxicity in mammalian cells.
CONCLUSION: These findings demonstrate the antibiofilm activity observed at the MBIC, along with the identification of tributyrin as a multi-target interacting compound, highlights the potential of V. tessellata-associated endophytic fungi as a promising source of anti-virulence agents. Together, this work provides a strong foundation for future molecular validation and in vivo evaluation of fungal-derived antibiofilm strategies.
Additional Links: PMID-42363969
PubMed:
Citation:
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@article {pmid42363969,
year = {2026},
author = {Rajeevan, P and Aneesa, A and Appukuttannair, G and Sugathan, S},
title = {Virulence modulation and biofilm inhibition of Streptococcus pyogenes by metabolites from endophytic fungi associated with Vanda tessellata.},
journal = {Molecular biology reports},
volume = {53},
number = {1},
pages = {},
pmid = {42363969},
issn = {1573-4978},
mesh = {*Biofilms/drug effects/growth & development ; *Streptococcus pyogenes/drug effects/pathogenicity ; Virulence/drug effects ; Microbial Sensitivity Tests ; *Endophytes/metabolism ; Anti-Bacterial Agents/pharmacology ; *Fungi/metabolism ; Animals ; Molecular Docking Simulation ; Humans ; },
abstract = {BACKGROUND: Endophytic fungi represent a valuable source of bioactive metabolites with potential applications in addressing antimicrobial resistance. Biofilm formation by Streptococcus pyogenes contributes to antibiotic tolerance and persistent infections, highlighting the need for alternative anti-virulence strategies.
METHODS AND RESULTS: In this study, endophytic fungi associated with the medicinal orchid Vanda tessellata were isolated and evaluated for their antimicrobial and antibiofilm activity against S. pyogenes using in vitro assays, microscopy, and viability analysis. Among the isolates, Nodulisporium verrucosum exhibited the strongest antibiofilm activity, achieving 90% inhibition at its minimum biofilm inhibitory concentration (MBIC) of 0.5 mg/mL, without affecting bacterial viability. Bioactivity-guided HR-LCMS analysis of the active extract revealed nine putative metabolites. Further computational ADMET profiling and molecular docking analyses identified tributyrin as a promising anti-virulence candidate, showing favorable pharmacokinetic properties and stable interactions with key biofilm-associated regulatory proteins of S. pyogenes. In addition, tributyrin demonstrated low cytotoxicity in mammalian cells.
CONCLUSION: These findings demonstrate the antibiofilm activity observed at the MBIC, along with the identification of tributyrin as a multi-target interacting compound, highlights the potential of V. tessellata-associated endophytic fungi as a promising source of anti-virulence agents. Together, this work provides a strong foundation for future molecular validation and in vivo evaluation of fungal-derived antibiofilm strategies.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/drug effects/growth & development
*Streptococcus pyogenes/drug effects/pathogenicity
Virulence/drug effects
Microbial Sensitivity Tests
*Endophytes/metabolism
Anti-Bacterial Agents/pharmacology
*Fungi/metabolism
Animals
Molecular Docking Simulation
Humans
RevDate: 2026-06-27
Genome-resolved metagenomics of an acid-tolerant nitrifying biofilm suggests cooperative nitrogen cycling at low pH.
The Science of the total environment, 1046:181954 pii:S0048-9697(26)00618-2 [Epub ahead of print].
Ammonia emissions from animal feeding operations are a major source of nitrogen loss and environmental pollution. Nitrifying bacteria used within ammonia scrubbers offers a promising strategy to recover nitrogen for fertilizer; however, the acidic environment within air scrubbers generally inhibits nitrification and sustained nitrification at low pH remains poorly understood. Here, we present a genome-resolved analysis of an acid-tolerant nitrifying community (ATNC) enriched from a laboratory bioreactor operating at pH values between 4 and 4.6 that was previously shown to support nitrification. Long-read metagenomic sequencing yielded 12 high-quality metagenome-assembled genomes accounting for 94.7% of community abundance, including four phylogenetically distinct Nitrospira representing both comammox and canonical nitrite-oxidizing lineages, alongside heterotrophic species of Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and a filamentous Ktedonobacterales strain. Genomic reconstruction suggested niche partitioning in nitrogen cycling, with comammox Nitrospira encoding the capacity for complete nitrification and Rhodanobacteraceae harboring genes associated with denitrification. Acid tolerance and biofilm persistence were associated with diverse ion-transport systems, alternative respiratory complexes, extracellular polymeric substance biosynthesis, and expanded repertoires of secreted proteases and carbohydrate-active enzymes that facilitate matrix turnover and carbon scavenging. Within the biofilm, Chloroflexi likely contribute structural scaffolding, while heterotrophs appear to be adapted for extracellular organic matter turnover and to act as metabolic partners. Together, these findings suggest that metabolic cooperation, functional redundancy, and biofilm-mediated resource sharing may support nitrification under acidic conditions. This work provides genome-resolved insight into the microbial processes potentially underpinning nitrification-enhanced ammonia capture and identifies candidate genomic features relevant to optimizing nitrogen recovery while minimizing denitrification-driven losses in engineered systems.
Additional Links: PMID-42364365
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PubMed:
Citation:
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@article {pmid42364365,
year = {2026},
author = {Manning, VA and Moore, PA and Medina, AR and Trippe, KM},
title = {Genome-resolved metagenomics of an acid-tolerant nitrifying biofilm suggests cooperative nitrogen cycling at low pH.},
journal = {The Science of the total environment},
volume = {1046},
number = {},
pages = {181954},
doi = {10.1016/j.scitotenv.2026.181954},
pmid = {42364365},
issn = {1879-1026},
abstract = {Ammonia emissions from animal feeding operations are a major source of nitrogen loss and environmental pollution. Nitrifying bacteria used within ammonia scrubbers offers a promising strategy to recover nitrogen for fertilizer; however, the acidic environment within air scrubbers generally inhibits nitrification and sustained nitrification at low pH remains poorly understood. Here, we present a genome-resolved analysis of an acid-tolerant nitrifying community (ATNC) enriched from a laboratory bioreactor operating at pH values between 4 and 4.6 that was previously shown to support nitrification. Long-read metagenomic sequencing yielded 12 high-quality metagenome-assembled genomes accounting for 94.7% of community abundance, including four phylogenetically distinct Nitrospira representing both comammox and canonical nitrite-oxidizing lineages, alongside heterotrophic species of Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and a filamentous Ktedonobacterales strain. Genomic reconstruction suggested niche partitioning in nitrogen cycling, with comammox Nitrospira encoding the capacity for complete nitrification and Rhodanobacteraceae harboring genes associated with denitrification. Acid tolerance and biofilm persistence were associated with diverse ion-transport systems, alternative respiratory complexes, extracellular polymeric substance biosynthesis, and expanded repertoires of secreted proteases and carbohydrate-active enzymes that facilitate matrix turnover and carbon scavenging. Within the biofilm, Chloroflexi likely contribute structural scaffolding, while heterotrophs appear to be adapted for extracellular organic matter turnover and to act as metabolic partners. Together, these findings suggest that metabolic cooperation, functional redundancy, and biofilm-mediated resource sharing may support nitrification under acidic conditions. This work provides genome-resolved insight into the microbial processes potentially underpinning nitrification-enhanced ammonia capture and identifies candidate genomic features relevant to optimizing nitrogen recovery while minimizing denitrification-driven losses in engineered systems.},
}
RevDate: 2026-06-27
From electron supply to electron economy: a unified framework for N2O control in membrane aerated biofilm reactors.
Water research, 304:126363 pii:S0043-1354(26)01042-0 [Epub ahead of print].
Membrane aerated biofilm reactors (MABRs) create a unique counter-diffusion biofilm through bubble-free aeration, spatially decoupling oxygen penetration from bulk substrate diffusion and thereby reshaping electron competition among nitrogen transformation pathways. This reactor-specific redox stratification offers a distinctive platform for selective nitrous oxide (N2O) control under low-carbon-to-nitrogen (C/N) conditions. Here, an Electron Economy Framework (EEF) is proposed to reinterpret nitrogen removal and N2O dynamics in MABRs from the integrated perspectives of electron source expansion and pathway prioritization. Within this framework, existing strategies are unified into three synergistic dimensions: (i) inorganic electron source expansion using hydrogen, reduced inorganic sulfur compounds, and iron-based materials to alleviate electron scarcity; (ii) electron demand and pathway regulation through ammonia diversion by PN/A, algal assimilation for nitrification bypass, and bioelectrochemical electron channeling to reduce reductive burden or selectively suppress N2O formation; and (iii) EEF based on the electron expansion and pathway regulation was proposed to quantify electron allocation toward target denitrification pathways, thereby improving electron utilization efficiency and mitigating N2O emissions. This framework bridges reactor architecture with electron resource management, providing a theoretical basis for low-carbon, high-efficiency nitrogen removal with minimized N2O emissions in next-generation biological treatment systems.
Additional Links: PMID-42364503
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PubMed:
Citation:
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@article {pmid42364503,
year = {2026},
author = {Yang, M and Hu, Y and Jiang, H and Yin, J and Cheng, Y and Liang, H and Zhang, H},
title = {From electron supply to electron economy: a unified framework for N2O control in membrane aerated biofilm reactors.},
journal = {Water research},
volume = {304},
number = {},
pages = {126363},
doi = {10.1016/j.watres.2026.126363},
pmid = {42364503},
issn = {1879-2448},
abstract = {Membrane aerated biofilm reactors (MABRs) create a unique counter-diffusion biofilm through bubble-free aeration, spatially decoupling oxygen penetration from bulk substrate diffusion and thereby reshaping electron competition among nitrogen transformation pathways. This reactor-specific redox stratification offers a distinctive platform for selective nitrous oxide (N2O) control under low-carbon-to-nitrogen (C/N) conditions. Here, an Electron Economy Framework (EEF) is proposed to reinterpret nitrogen removal and N2O dynamics in MABRs from the integrated perspectives of electron source expansion and pathway prioritization. Within this framework, existing strategies are unified into three synergistic dimensions: (i) inorganic electron source expansion using hydrogen, reduced inorganic sulfur compounds, and iron-based materials to alleviate electron scarcity; (ii) electron demand and pathway regulation through ammonia diversion by PN/A, algal assimilation for nitrification bypass, and bioelectrochemical electron channeling to reduce reductive burden or selectively suppress N2O formation; and (iii) EEF based on the electron expansion and pathway regulation was proposed to quantify electron allocation toward target denitrification pathways, thereby improving electron utilization efficiency and mitigating N2O emissions. This framework bridges reactor architecture with electron resource management, providing a theoretical basis for low-carbon, high-efficiency nitrogen removal with minimized N2O emissions in next-generation biological treatment systems.},
}
RevDate: 2026-06-28
CmpDate: 2026-06-28
Pathogens in the bay: environmental Staphylococcus saprophyticus strains mirror clinical counterparts in virulence, biofilm formation, antimicrobial resistance, pathogenicity, and phage susceptibility.
Antonie van Leeuwenhoek, 119(7):.
Staphylococcus saprophyticus is a leading cause of urinary tract infections, yet little is known about its environmental reservoirs and traits outside clinical settings. This study aimed to compare clinical and environmental S. saprophyticus strains isolated from a polluted coastal ecosystem in Brazil, assessing their virulence-associated traits, antimicrobial resistance, biofilm formation, and susceptibility to bacteriophages. Forty strains (20 clinical, 20 environmental) were characterized using GTG5-PCR, virulence gene screening, antibiotic susceptibility testing, biofilm assays, exposure to sub-inhibitory concentrations of ciprofloxacin, Tenebrio molitor infection model, and phage activity tests. Genetic fingerprinting and virulence gene profiles revealed a high degree of similarity between environmental and clinical isolates, indicating the presence of shared virulence-associated determinants. Environmental strains exhibited resistance to multiple antibiotics and showed biofilm formation and larval survival patterns comparable to those observed for clinical isolates. Exposure to sub-inhibitory concentrations of ciprofloxacin increased biofilm formation in several strains. Bacteriophage CSF, originally isolated from swine farm effluent, displayed lytic and antibiofilm activity against a substantial proportion of the isolates. These findings highlight the presence of clinically relevant traits among environmental S. saprophyticus strains and underscore the importance of continued microbiological surveillance in anthropized aquatic environments.
Additional Links: PMID-42365575
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@article {pmid42365575,
year = {2026},
author = {Monteiro Carvalho, I and Soares E Silva, EC and Lacerda Rodrigues, G and Duarte Dos Santos, N and da Silva Soares, RV and Pereira, MF and Rossi, CC and Giambiagi-deMarval, M},
title = {Pathogens in the bay: environmental Staphylococcus saprophyticus strains mirror clinical counterparts in virulence, biofilm formation, antimicrobial resistance, pathogenicity, and phage susceptibility.},
journal = {Antonie van Leeuwenhoek},
volume = {119},
number = {7},
pages = {},
pmid = {42365575},
issn = {1572-9699},
support = {APQ-03498-22; BIP-00178-24//Fundação de Amparo à Pesquisa do Estado de Minas Gerais/ ; 313528/2021-7, 304839/2022-1; 408564/2023-7; 309158/2023-0, 408678/2024-0//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; 23038.002486/2018-26//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; E-26/010.000172/2016; 010.00128/2016; E-26.210.875/2016, 101056/2018; 001463/2019; 211.554/2019; 201.071/2020,200.895/2021; E-26/204.925/2022; E-26/211.284/2021 and E-26/204.045/2024//Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro/ ; },
mesh = {*Biofilms/growth & development ; Virulence ; Animals ; Brazil ; Anti-Bacterial Agents/pharmacology ; *Staphylococcus saprophyticus/virology/drug effects/pathogenicity/genetics/isolation & purification/physiology ; *Drug Resistance, Bacterial ; Staphylococcal Infections/microbiology ; Microbial Sensitivity Tests ; Humans ; *Bacteriophages/physiology ; Staphylococcus Phages/physiology ; Virulence Factors/genetics ; },
abstract = {Staphylococcus saprophyticus is a leading cause of urinary tract infections, yet little is known about its environmental reservoirs and traits outside clinical settings. This study aimed to compare clinical and environmental S. saprophyticus strains isolated from a polluted coastal ecosystem in Brazil, assessing their virulence-associated traits, antimicrobial resistance, biofilm formation, and susceptibility to bacteriophages. Forty strains (20 clinical, 20 environmental) were characterized using GTG5-PCR, virulence gene screening, antibiotic susceptibility testing, biofilm assays, exposure to sub-inhibitory concentrations of ciprofloxacin, Tenebrio molitor infection model, and phage activity tests. Genetic fingerprinting and virulence gene profiles revealed a high degree of similarity between environmental and clinical isolates, indicating the presence of shared virulence-associated determinants. Environmental strains exhibited resistance to multiple antibiotics and showed biofilm formation and larval survival patterns comparable to those observed for clinical isolates. Exposure to sub-inhibitory concentrations of ciprofloxacin increased biofilm formation in several strains. Bacteriophage CSF, originally isolated from swine farm effluent, displayed lytic and antibiofilm activity against a substantial proportion of the isolates. These findings highlight the presence of clinically relevant traits among environmental S. saprophyticus strains and underscore the importance of continued microbiological surveillance in anthropized aquatic environments.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
Virulence
Animals
Brazil
Anti-Bacterial Agents/pharmacology
*Staphylococcus saprophyticus/virology/drug effects/pathogenicity/genetics/isolation & purification/physiology
*Drug Resistance, Bacterial
Staphylococcal Infections/microbiology
Microbial Sensitivity Tests
Humans
*Bacteriophages/physiology
Staphylococcus Phages/physiology
Virulence Factors/genetics
RevDate: 2026-06-29
CmpDate: 2026-06-29
Comprehensive Analysis of Artemisia argyi H. Lév. & Vaniot Essential Oil: Chemical Composition, Antimicrobial Efficacy, Biofilm Disruption, and Insecticidal Potential.
Food science & nutrition, 14(6):e71385.
Artemisia argyi is a traditional medicinal plant known for its broad spectrum of biological activities, including antimicrobial, anti-inflammatory, and insecticidal effects. In this study, the essential oil (EO) extracted from the leaves of A. argyi (AAEO) was comprehensively analyzed by GC-MS to determine its chemical composition. The antimicrobial efficacy was evaluated in vitro by disc diffusion and determination of minimum inhibitory concentrations (MIC) against selected bacterial and yeast pathogens. The antimicrobial effect was tested in situ on various food matrices (apple, banana, beetroot, cucumber) by vapor phase exposure. Antibiofilm activity was evaluated by crystal violet assay and MALDI-TOF MS analysis of biofilm samples. The insecticidal activity was evaluated against the pest Callosobruchus maculatus. The results showed that AAEO consists predominantly of 1,8-cineole (20.5%), β-caryophyllene (16.5%) and longifolene (13.8%). The oil showed mild to moderate antimicrobial activity, with stronger effects against Gram-positive bacteria, and significantly inhibited microbial growth on food matrices, with efficacy depending on the type of matrix and oil concentration. AAEO also reduced the biofilm formation of Salmonella enterica, which was confirmed by changes in the MALDI-TOF MS spectra of the biofilm. Insecticidal activity was significant at concentrations of 25% and above, with 100% mortality achieved at a concentration of 100%. These results support the potential of AAEO as a natural bioactive agent suitable for food safety, crop protection and integrated pest management applications.
Additional Links: PMID-42369647
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Citation:
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@article {pmid42369647,
year = {2026},
author = {Kačániová, M and Ban, Z and Li, L and Lou, J and Elizondo-Luevano, JH and Ben Hsouna, A and Ben Saad, R and Bianchi, A and Bakay, L and Garzoli, S},
title = {Comprehensive Analysis of Artemisia argyi H. Lév. & Vaniot Essential Oil: Chemical Composition, Antimicrobial Efficacy, Biofilm Disruption, and Insecticidal Potential.},
journal = {Food science & nutrition},
volume = {14},
number = {6},
pages = {e71385},
pmid = {42369647},
issn = {2048-7177},
abstract = {Artemisia argyi is a traditional medicinal plant known for its broad spectrum of biological activities, including antimicrobial, anti-inflammatory, and insecticidal effects. In this study, the essential oil (EO) extracted from the leaves of A. argyi (AAEO) was comprehensively analyzed by GC-MS to determine its chemical composition. The antimicrobial efficacy was evaluated in vitro by disc diffusion and determination of minimum inhibitory concentrations (MIC) against selected bacterial and yeast pathogens. The antimicrobial effect was tested in situ on various food matrices (apple, banana, beetroot, cucumber) by vapor phase exposure. Antibiofilm activity was evaluated by crystal violet assay and MALDI-TOF MS analysis of biofilm samples. The insecticidal activity was evaluated against the pest Callosobruchus maculatus. The results showed that AAEO consists predominantly of 1,8-cineole (20.5%), β-caryophyllene (16.5%) and longifolene (13.8%). The oil showed mild to moderate antimicrobial activity, with stronger effects against Gram-positive bacteria, and significantly inhibited microbial growth on food matrices, with efficacy depending on the type of matrix and oil concentration. AAEO also reduced the biofilm formation of Salmonella enterica, which was confirmed by changes in the MALDI-TOF MS spectra of the biofilm. Insecticidal activity was significant at concentrations of 25% and above, with 100% mortality achieved at a concentration of 100%. These results support the potential of AAEO as a natural bioactive agent suitable for food safety, crop protection and integrated pest management applications.},
}
RevDate: 2026-06-29
Calcium-enhanced COF platforms for synergistic photothermal-antibacterial therapy: Unlocking calcium-mediated membrane disruption and ion overload for bacterial and biofilm eradication in wound care and clinical nursing.
Biomaterials advances, 188:215042 pii:S2772-9508(26)00340-7 [Epub ahead of print].
The escalating threat of antibiotic-resistant bacteria and biofilm-associated infections necessitates the development of non-antibiotic therapeutic strategies with novel mechanisms of action. Here, we report a synergistic antibacterial platform based on a calcium-functionalized covalent organic framework (BQ-Ca-COF), designed to exploit the dual role of calcium ions (Ca[2+]) as both structural modulators and bioactive effectors. Using a solvothermal approach, we synthesized a series of COFs incorporating a dipyrazino [2,3-f:2',3'-h] quinoxalin (DPQ) linkage, enabling precise regulation of both framework architecture and Ca[2+] incorporation. The optimized BQ-Ca-COF exhibits a hierarchically porous structure and achieves a remarkable photothermal conversion efficiency of 58% under 638 nm laser irradiation. Crucially, Ca[2+] serve as the linchpin of a multi-stage synergistic cascade, with their role evolving across each phase of the therapeutic process. Beyond merely integrating into the COF skeleton as a structural enhancer, Ca[2+] optimizes electronic properties to amplify photothermal heat generation. Upon release, these ions then transition to function as membrane destabilizers, electrostatically disrupting bacterial membranes and increasing their permeability that sensitizes bacteria to subsequent photothermal insult. This sensitization sets the stage triggers an uncontrolled influx of extracellular Ca[2+]. The resulting "calcium overload" disrupts bacterial homeostasis, causes an imbalance in membrane potential, and triggers apoptosis-like death. High temperatures directly cause protein conformational instability and loss of function, leading to a significant decrease in the activity of transmembrane proteins such as the calcium efflux pump. Moreover, elevated temperatures compromise membrane lipid fluidity and integrity, further disrupting calcium transporter function. The resulting breakdown of calcium ion homeostasis triggers a lethal cascade, culminating in irreversible bacterial death. This synergistic mechanism enables BQ-Ca-COF to achieve >99% eradication of both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, along with nearly complete (∼100%) biofilm disruption, substantially outperforming calcium-free control (BQ-COF). The material exhibits excellent biocompatibility, low cytotoxicity, and promotes cell migration. When processed into a medical hydrogel dressing for clinical wound care evaluation, BQ-Ca-COF maintains stable photothermal performance even after 100 bending cycles and causes no skin irritation during prolonged wear. In a mouse infection model, BQ-Ca-COF combined with laser irradiation significantly accelerated wound healing compared to controls, with no evidence of systemic toxicity. This work establishes a new paradigm for designing COF-based multifunctional antibacterial platforms and, more importantly, elucidates the pivotal and multifaceted role of Ca[2+] as structural architects, membrane permeabilizers, and mediators of fatal ion overload in achieving potent, resistance-free antibacterial therapy against clinically relevant infections.
Additional Links: PMID-42372388
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PubMed:
Citation:
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@article {pmid42372388,
year = {2026},
author = {Jiang, Y and Wu, W and Yang, S and Lu, K and Li, H and Yang, Z and Pang, Z and Yang, H and Si, S and Zhou, B and Ji, W and Sun, X},
title = {Calcium-enhanced COF platforms for synergistic photothermal-antibacterial therapy: Unlocking calcium-mediated membrane disruption and ion overload for bacterial and biofilm eradication in wound care and clinical nursing.},
journal = {Biomaterials advances},
volume = {188},
number = {},
pages = {215042},
doi = {10.1016/j.bioadv.2026.215042},
pmid = {42372388},
issn = {2772-9508},
abstract = {The escalating threat of antibiotic-resistant bacteria and biofilm-associated infections necessitates the development of non-antibiotic therapeutic strategies with novel mechanisms of action. Here, we report a synergistic antibacterial platform based on a calcium-functionalized covalent organic framework (BQ-Ca-COF), designed to exploit the dual role of calcium ions (Ca[2+]) as both structural modulators and bioactive effectors. Using a solvothermal approach, we synthesized a series of COFs incorporating a dipyrazino [2,3-f:2',3'-h] quinoxalin (DPQ) linkage, enabling precise regulation of both framework architecture and Ca[2+] incorporation. The optimized BQ-Ca-COF exhibits a hierarchically porous structure and achieves a remarkable photothermal conversion efficiency of 58% under 638 nm laser irradiation. Crucially, Ca[2+] serve as the linchpin of a multi-stage synergistic cascade, with their role evolving across each phase of the therapeutic process. Beyond merely integrating into the COF skeleton as a structural enhancer, Ca[2+] optimizes electronic properties to amplify photothermal heat generation. Upon release, these ions then transition to function as membrane destabilizers, electrostatically disrupting bacterial membranes and increasing their permeability that sensitizes bacteria to subsequent photothermal insult. This sensitization sets the stage triggers an uncontrolled influx of extracellular Ca[2+]. The resulting "calcium overload" disrupts bacterial homeostasis, causes an imbalance in membrane potential, and triggers apoptosis-like death. High temperatures directly cause protein conformational instability and loss of function, leading to a significant decrease in the activity of transmembrane proteins such as the calcium efflux pump. Moreover, elevated temperatures compromise membrane lipid fluidity and integrity, further disrupting calcium transporter function. The resulting breakdown of calcium ion homeostasis triggers a lethal cascade, culminating in irreversible bacterial death. This synergistic mechanism enables BQ-Ca-COF to achieve >99% eradication of both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, along with nearly complete (∼100%) biofilm disruption, substantially outperforming calcium-free control (BQ-COF). The material exhibits excellent biocompatibility, low cytotoxicity, and promotes cell migration. When processed into a medical hydrogel dressing for clinical wound care evaluation, BQ-Ca-COF maintains stable photothermal performance even after 100 bending cycles and causes no skin irritation during prolonged wear. In a mouse infection model, BQ-Ca-COF combined with laser irradiation significantly accelerated wound healing compared to controls, with no evidence of systemic toxicity. This work establishes a new paradigm for designing COF-based multifunctional antibacterial platforms and, more importantly, elucidates the pivotal and multifaceted role of Ca[2+] as structural architects, membrane permeabilizers, and mediators of fatal ion overload in achieving potent, resistance-free antibacterial therapy against clinically relevant infections.},
}
RevDate: 2026-06-27
Benzyl isothiocyanate-loaded chitosan beads: a novel strategy to combat biofilm formation by Staphylococcus aureus and Escherichia coli.
Future microbiology [Epub ahead of print].
AIMS: This study aimed to develop and evaluate chitosan beads loaded with benzyl isothiocyanate (BITC) as a novel therapeutic strategy to combat biofilm-associated infections caused by Staphylococcus aureus and Escherichia coli.
METHODS: The beads were fabricated via ionic gelation and characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and ultraviolet-visible spectrophotometry (UV-Vis). Antibacterial and antibiofilm activities of the optimal formulation BITC-loaded beads (B-Cs2) were assessed. Supporting computational analyses (molecular docking) were carried out; detailed methods and results are provided in the Supplementary Material.
RESULTS: B-Cs2 beads (10 mg) exhibited strong antibacterial activity, producing inhibition zones of 34.0 ± 1.0 mm for S. aureus and 24.0 ± 2.0 mm for E. coli. The formulation also significantly inhibited biofilm formation, reducing it by 49.3% in S. aureus and 48.2% in E. coli. Molecular docking predicted potential interactions with key virulence proteins, suggesting that BITC may disrupt distinct virulence pathways; however, further biochemical validation is required to confirm these proposed mechanisms.
CONCLUSION: BITC-loaded chitosan beads function as a dual-action system with potent antibacterial and antibiofilm properties, demonstrating significant potential for applications in clinical therapeutics and food safety.
Additional Links: PMID-42363868
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PubMed:
Citation:
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@article {pmid42363868,
year = {2026},
author = {Ulusoy, S and Periz, ÇD and Kaya Kınaytürk, N},
title = {Benzyl isothiocyanate-loaded chitosan beads: a novel strategy to combat biofilm formation by Staphylococcus aureus and Escherichia coli.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {1-13},
doi = {10.1080/17460913.2026.2688706},
pmid = {42363868},
issn = {1746-0921},
abstract = {AIMS: This study aimed to develop and evaluate chitosan beads loaded with benzyl isothiocyanate (BITC) as a novel therapeutic strategy to combat biofilm-associated infections caused by Staphylococcus aureus and Escherichia coli.
METHODS: The beads were fabricated via ionic gelation and characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and ultraviolet-visible spectrophotometry (UV-Vis). Antibacterial and antibiofilm activities of the optimal formulation BITC-loaded beads (B-Cs2) were assessed. Supporting computational analyses (molecular docking) were carried out; detailed methods and results are provided in the Supplementary Material.
RESULTS: B-Cs2 beads (10 mg) exhibited strong antibacterial activity, producing inhibition zones of 34.0 ± 1.0 mm for S. aureus and 24.0 ± 2.0 mm for E. coli. The formulation also significantly inhibited biofilm formation, reducing it by 49.3% in S. aureus and 48.2% in E. coli. Molecular docking predicted potential interactions with key virulence proteins, suggesting that BITC may disrupt distinct virulence pathways; however, further biochemical validation is required to confirm these proposed mechanisms.
CONCLUSION: BITC-loaded chitosan beads function as a dual-action system with potent antibacterial and antibiofilm properties, demonstrating significant potential for applications in clinical therapeutics and food safety.},
}
RevDate: 2026-06-26
Quatsome nanovesicles as antibacterial platform: Mechanistic insights into their activity against planktonic and biofilm Staphylococcus aureus.
Colloids and surfaces. B, Biointerfaces, 267:115932 pii:S0927-7765(26)00520-5 [Epub ahead of print].
The growing threat of antibiotic-resistant pathogens has intensified the demand for alternative antibacterial materials. Quatsomes-nanovesicles composed of cholesterol and quaternary ammonium surfactants (QAS)-emerge as promising candidates due to their intrinsic antimicrobial properties and tunable physicochemical characteristics. Here, we investigate the antibacterial activity of quatsomes incorporating QAS with either tetradecyl (C14) or hexadecyl (C16) alkyl chains against Staphylococcus aureus, a leading cause of hospital-acquired infections. Both quatsome types exhibited potent bactericidal activity in planktonic cultures, with C16-containing formulations showing a 2.5-fold lower minimum bactericidal concentration than C14 counterparts. Confocal microscopy suggested a partial penetration of cationic quatsomes into the bacterial peptidoglycan layer, accompanied by significant increases in ζ-potential, suggesting strong electrostatic interactions without visible membrane disruption, as confirmed by scanning electron microscopy. Both formulations also demonstrated high efficacy against mature S. aureus biofilms, with no significant differences between alkyl chain lengths, indicating a mechanism primarily targeting the extracellular biofilm matrix. In addition, they showed a good antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). A preliminary safety assessment using reconstructed human epidermis (Episkin™) confirmed the non-irritant nature of both formulations. These findings highlight the potential of QAS-based quatsomes as effective and biocompatible nanocarriers for topical antibacterial applications, offering a promising platform for combating antibiotic-resistant infections in both planktonic and biofilm states.
Additional Links: PMID-42361591
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PubMed:
Citation:
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@article {pmid42361591,
year = {2026},
author = {Köber, M and Gallardo-Moreno, AM and Ferrer-Tasies, L and Fernández-Calderón, MC and Pujol-Solé, N and Tomsen-Melero, J and Guasch, E and Tamurejo-Alonso, P and Mitjans, M and Vinardell, MP and Domingo-Tafalla, B and Giannotti, MI and Rancan, F and Schaudinn, C and Veciana, J and Ratera, I and Roldán, M and González-Mira, E and González-Martín, ML and Ventosa, N},
title = {Quatsome nanovesicles as antibacterial platform: Mechanistic insights into their activity against planktonic and biofilm Staphylococcus aureus.},
journal = {Colloids and surfaces. B, Biointerfaces},
volume = {267},
number = {},
pages = {115932},
doi = {10.1016/j.colsurfb.2026.115932},
pmid = {42361591},
issn = {1873-4367},
abstract = {The growing threat of antibiotic-resistant pathogens has intensified the demand for alternative antibacterial materials. Quatsomes-nanovesicles composed of cholesterol and quaternary ammonium surfactants (QAS)-emerge as promising candidates due to their intrinsic antimicrobial properties and tunable physicochemical characteristics. Here, we investigate the antibacterial activity of quatsomes incorporating QAS with either tetradecyl (C14) or hexadecyl (C16) alkyl chains against Staphylococcus aureus, a leading cause of hospital-acquired infections. Both quatsome types exhibited potent bactericidal activity in planktonic cultures, with C16-containing formulations showing a 2.5-fold lower minimum bactericidal concentration than C14 counterparts. Confocal microscopy suggested a partial penetration of cationic quatsomes into the bacterial peptidoglycan layer, accompanied by significant increases in ζ-potential, suggesting strong electrostatic interactions without visible membrane disruption, as confirmed by scanning electron microscopy. Both formulations also demonstrated high efficacy against mature S. aureus biofilms, with no significant differences between alkyl chain lengths, indicating a mechanism primarily targeting the extracellular biofilm matrix. In addition, they showed a good antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). A preliminary safety assessment using reconstructed human epidermis (Episkin™) confirmed the non-irritant nature of both formulations. These findings highlight the potential of QAS-based quatsomes as effective and biocompatible nanocarriers for topical antibacterial applications, offering a promising platform for combating antibiotic-resistant infections in both planktonic and biofilm states.},
}
RevDate: 2026-06-26
Influence of Prosthetic Surface Roughness on Biofilm Density and Prosthesis Longevity.
Microbial pathogenesis pii:S0882-4010(26)00388-8 [Epub ahead of print].
Dental prosthesis failure is often associated with biofilm-mediated infections, yet the combined roles of surface roughness and material chemistry remain underexplored. This observational, retrospective study investigated associations between these factors and biofilm density, pathogen selection, and prosthesis longevity. Surface roughness (Ra) and microbial colonization were analyzed for 85 explanted prostheses (fixed, removable, implant-supported, and orthodontic) and compared to control samples (polished enamel, sealants). Biofilm formation was quantified via optical density (OD) and colony-forming units (CFU/cm[2]), while pathogen profiles were identified using selective culture and biochemical assays. A strong positive correlation (R[2] = 0.84, interpreted as a very strong correlation according to Evans' (1996) classification) was observed between surface roughness and biofilm accumulation. Smooth surfaces like zirconia (Ra ∼320 nm) exhibited low biofilm (OD 0.45), whereas rougher surfaces, particularly removable PMMA dentures (Ra ∼1100 nm), showed dense biofilms (OD up to 1.85) dominated by Candida spp. and Pseudomonas aeruginosa. Material chemistry was associated with distinct pathogen profiles: PMMA favored fungal and Gram-negative adhesion, while titanium promoted staphylococcal colonization. In this cohort, biofilm-associated infections were associated with reduced functional longevity; for example, implant crowns designed for 15+ years were removed after a mean of 5.4 years due to peri-implantitis. The study concludes that prosthetic failure is associated with the synergistic effect of surface topography, which correlates with biofilm quantity, and material composition, which is associated with distinct microbial ecology. These findings underscore the need for prostheses engineered with optimized surface smoothness and antimicrobial material chemistry. However, the observational, retrospective design limits causal inference; the culture-based methodology likely underestimates the full microbial diversity, particularly of anaerobic species; and the heterogeneity of device types limits direct comparability between groups.
Additional Links: PMID-42361993
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PubMed:
Citation:
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@article {pmid42361993,
year = {2026},
author = {Kazmi, SAD and Jabeen, B and Huda, NU and Urooj, S and Khan, FZ and Abbas, T and Mirani, ZA},
title = {Influence of Prosthetic Surface Roughness on Biofilm Density and Prosthesis Longevity.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {108662},
doi = {10.1016/j.micpath.2026.108662},
pmid = {42361993},
issn = {1096-1208},
abstract = {Dental prosthesis failure is often associated with biofilm-mediated infections, yet the combined roles of surface roughness and material chemistry remain underexplored. This observational, retrospective study investigated associations between these factors and biofilm density, pathogen selection, and prosthesis longevity. Surface roughness (Ra) and microbial colonization were analyzed for 85 explanted prostheses (fixed, removable, implant-supported, and orthodontic) and compared to control samples (polished enamel, sealants). Biofilm formation was quantified via optical density (OD) and colony-forming units (CFU/cm[2]), while pathogen profiles were identified using selective culture and biochemical assays. A strong positive correlation (R[2] = 0.84, interpreted as a very strong correlation according to Evans' (1996) classification) was observed between surface roughness and biofilm accumulation. Smooth surfaces like zirconia (Ra ∼320 nm) exhibited low biofilm (OD 0.45), whereas rougher surfaces, particularly removable PMMA dentures (Ra ∼1100 nm), showed dense biofilms (OD up to 1.85) dominated by Candida spp. and Pseudomonas aeruginosa. Material chemistry was associated with distinct pathogen profiles: PMMA favored fungal and Gram-negative adhesion, while titanium promoted staphylococcal colonization. In this cohort, biofilm-associated infections were associated with reduced functional longevity; for example, implant crowns designed for 15+ years were removed after a mean of 5.4 years due to peri-implantitis. The study concludes that prosthetic failure is associated with the synergistic effect of surface topography, which correlates with biofilm quantity, and material composition, which is associated with distinct microbial ecology. These findings underscore the need for prostheses engineered with optimized surface smoothness and antimicrobial material chemistry. However, the observational, retrospective design limits causal inference; the culture-based methodology likely underestimates the full microbial diversity, particularly of anaerobic species; and the heterogeneity of device types limits direct comparability between groups.},
}
RevDate: 2026-06-26
Seasonal variation in plastic-associated biofilm microbial assemblages: a microcosm approach.
Environmental monitoring and assessment, 198(7):.
Plastic pollution in natural ecosystems creates novel niches, known as the "Plastisphere", that host heterogeneous microbial communities shaped by substrate type and environmental conditions. This study explored the effects of seasonal variation on the plastisphere evolution on different plastic substrates, oxo-degradable carrier bags (Oxo), oxo-degradable garbage bags (Oxo-G), normal plastics (N), and snack packets (Sn) for 30 days in a microcosm experiment using ambient water from the monsoon-influenced Zuari estuary. The results indicated that the early-stage (day 5) plastisphere was dominated by fast-growing r-strategists, such as Alpha- and Gamma-proteobacteria as well as Campylobacterota-related lineages, whereas mature biofilms (day 30) showed increased abundance of secondary colonisers, including Planctomycetota, Actinomycetota, and Bacteroidota. The oxo-degradable plastics emerged as preferred substrates, likely due to their prooxidant-mediated abiotic degradation and the novel nature of the conditioning film. Salinity, in conjunction with nutrient concentrations, emerged as a major driver of microbial abundance in the plastisphere. Though the putative pathogens, such as Vibrio spp. and total coliforms, were present at very low abundance in the aged plastisphere during the SW-Mon and PostM seasons, their persistence indicates their resilience even under nutrient-limited conditions. Although a closed microcosm system probably introduced bottle effects, influencing temporal changes in nutrient levels and microbial abundance, the study provides baseline insights into substrate- and season-driven patterns of plastisphere development. Overall, these findings underscore the dynamic interplay among various factors, including plastic types and seasonal environmental shifts, in shaping plastisphere maturation. This has potential implications for public health and ecosystem functioning in the natural marine environment. Employing functional metagenomics analysis in future in situ studies of plastisphere communities can provide further insights and is a way forward for predicting associated ecological risks.
Additional Links: PMID-42362787
PubMed:
Citation:
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@article {pmid42362787,
year = {2026},
author = {Sinha, B and Khandeparker, L},
title = {Seasonal variation in plastic-associated biofilm microbial assemblages: a microcosm approach.},
journal = {Environmental monitoring and assessment},
volume = {198},
number = {7},
pages = {},
pmid = {42362787},
issn = {1573-2959},
abstract = {Plastic pollution in natural ecosystems creates novel niches, known as the "Plastisphere", that host heterogeneous microbial communities shaped by substrate type and environmental conditions. This study explored the effects of seasonal variation on the plastisphere evolution on different plastic substrates, oxo-degradable carrier bags (Oxo), oxo-degradable garbage bags (Oxo-G), normal plastics (N), and snack packets (Sn) for 30 days in a microcosm experiment using ambient water from the monsoon-influenced Zuari estuary. The results indicated that the early-stage (day 5) plastisphere was dominated by fast-growing r-strategists, such as Alpha- and Gamma-proteobacteria as well as Campylobacterota-related lineages, whereas mature biofilms (day 30) showed increased abundance of secondary colonisers, including Planctomycetota, Actinomycetota, and Bacteroidota. The oxo-degradable plastics emerged as preferred substrates, likely due to their prooxidant-mediated abiotic degradation and the novel nature of the conditioning film. Salinity, in conjunction with nutrient concentrations, emerged as a major driver of microbial abundance in the plastisphere. Though the putative pathogens, such as Vibrio spp. and total coliforms, were present at very low abundance in the aged plastisphere during the SW-Mon and PostM seasons, their persistence indicates their resilience even under nutrient-limited conditions. Although a closed microcosm system probably introduced bottle effects, influencing temporal changes in nutrient levels and microbial abundance, the study provides baseline insights into substrate- and season-driven patterns of plastisphere development. Overall, these findings underscore the dynamic interplay among various factors, including plastic types and seasonal environmental shifts, in shaping plastisphere maturation. This has potential implications for public health and ecosystem functioning in the natural marine environment. Employing functional metagenomics analysis in future in situ studies of plastisphere communities can provide further insights and is a way forward for predicting associated ecological risks.},
}
RevDate: 2026-06-26
Complete genome sequence of Streptomyces californicus ADR1, an anti-infective, anti-biofilm and anti-oxidant producing endophyte isolated from the medicinal plant Datura metel.
BMC genomic data pii:10.1186/s12863-026-01459-x [Epub ahead of print].
OBJECTIVE: Streptomyces californicus strain ADR1 is an endophytic actinobacterium isolated from Datura metel that produces secondary metabolites with potent antibacterial and anti-biofilm activities against WHO-listed high-priority Gram-positive pathogens. While anti-bacterial and antioxidant potential of the strain ADR1 has been extensively characterized, its complete genome sequence remains to be investigated for further insights into its biosynthetic potential. This study presents the complete genome sequence analysis of the strain ADR1 to provide a robust genomic foundation for understanding its metabolic versatility and biosynthesis of compounds with therapeutic significance.
DATA DESCRIPTION: The ADR1 genome was sequenced using Illumina HiSeq. The assembly comprised 262 scaffolds with a total genome size of 8.4 Mb and G + C content of 72.5%, containing 7427 protein-coding genes. AntiSMASH and IIT-Hyderabad novelBGC analysis revealed 39 biosynthetic gene clusters, including non-ribosomal peptide synthetases, type I polyketide synthases, terpene and melanin clusters, correlating with the diverse therapeutic compounds previously identified through GC-MS analysis. This high-quality genome provides crucial insights into the biosynthetic potential underlying potent antimicrobial and antioxidant activities of the strain ADR1.
Additional Links: PMID-42363069
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PubMed:
Citation:
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@article {pmid42363069,
year = {2026},
author = {Yadav, K and Phogat, S and Verma, V and Dubey, AK},
title = {Complete genome sequence of Streptomyces californicus ADR1, an anti-infective, anti-biofilm and anti-oxidant producing endophyte isolated from the medicinal plant Datura metel.},
journal = {BMC genomic data},
volume = {},
number = {},
pages = {},
doi = {10.1186/s12863-026-01459-x},
pmid = {42363069},
issn = {2730-6844},
abstract = {OBJECTIVE: Streptomyces californicus strain ADR1 is an endophytic actinobacterium isolated from Datura metel that produces secondary metabolites with potent antibacterial and anti-biofilm activities against WHO-listed high-priority Gram-positive pathogens. While anti-bacterial and antioxidant potential of the strain ADR1 has been extensively characterized, its complete genome sequence remains to be investigated for further insights into its biosynthetic potential. This study presents the complete genome sequence analysis of the strain ADR1 to provide a robust genomic foundation for understanding its metabolic versatility and biosynthesis of compounds with therapeutic significance.
DATA DESCRIPTION: The ADR1 genome was sequenced using Illumina HiSeq. The assembly comprised 262 scaffolds with a total genome size of 8.4 Mb and G + C content of 72.5%, containing 7427 protein-coding genes. AntiSMASH and IIT-Hyderabad novelBGC analysis revealed 39 biosynthetic gene clusters, including non-ribosomal peptide synthetases, type I polyketide synthases, terpene and melanin clusters, correlating with the diverse therapeutic compounds previously identified through GC-MS analysis. This high-quality genome provides crucial insights into the biosynthetic potential underlying potent antimicrobial and antioxidant activities of the strain ADR1.},
}
RevDate: 2026-06-25
CmpDate: 2026-06-26
Research progress on biofilm-driven microplastic sedimentation.
Ying yong sheng tai xue bao = The journal of applied ecology, 37(5):1717-1730.
Biofilms play a crucial role in regulating the behavior of microplastics (MPs) in aquatic environments, yet their dynamic mechanisms have often been overlooked in traditional models. We reviewed the formation mechanism of biofilm and its impact on the sedimentation behavior of MPs. Upon entering water, MPs are rapidly colonized by microorganisms, forming biofilm structures composed of extracellular polymeric substances (EPS) and microbial communities. This process is influenced by exposure time, environmental conditions, and the intrinsic properties of MPs. Biofilms significantly affect MPs sedimentation and vertical distribution by increasing their effective density, promoting aggregation, and altering surface properties, challenging the applicability of prediction models based solely on physical attributes. Microorganisms (particularly microalgae) and their EPS secretions are key factors driving sedimentation differences. We further summarized current research progress on biofilm-MPs interactions, their applications, and limitations. Future research should focus on the following areas. Mechanistically, we should develop multiscale models that integrate biofilm dynamics with hydraulic conditions. Methodologically, we should advance in-situ observation techniques to quantitatively characterize biofilm properties such as EPS composition and community function. From an application perspective, we should explore bioremediation strategies that use functional microorganisms, such as specific algae or bacteria, to control MPs sedimentation.
Additional Links: PMID-42350146
Publisher:
PubMed:
Citation:
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@article {pmid42350146,
year = {2026},
author = {Cao, YQ and Chen, XY and Kong, LT and Deng, DG and Shi, JH and Fang, WJ},
title = {Research progress on biofilm-driven microplastic sedimentation.},
journal = {Ying yong sheng tai xue bao = The journal of applied ecology},
volume = {37},
number = {5},
pages = {1717-1730},
doi = {10.13287/j.1001-9332.202605.031},
pmid = {42350146},
issn = {1001-9332},
mesh = {*Biofilms/growth & development ; *Microplastics/metabolism/isolation & purification ; Extracellular Polymeric Substance Matrix ; *Water Pollutants, Chemical ; Biodegradation, Environmental ; Bacteria ; },
abstract = {Biofilms play a crucial role in regulating the behavior of microplastics (MPs) in aquatic environments, yet their dynamic mechanisms have often been overlooked in traditional models. We reviewed the formation mechanism of biofilm and its impact on the sedimentation behavior of MPs. Upon entering water, MPs are rapidly colonized by microorganisms, forming biofilm structures composed of extracellular polymeric substances (EPS) and microbial communities. This process is influenced by exposure time, environmental conditions, and the intrinsic properties of MPs. Biofilms significantly affect MPs sedimentation and vertical distribution by increasing their effective density, promoting aggregation, and altering surface properties, challenging the applicability of prediction models based solely on physical attributes. Microorganisms (particularly microalgae) and their EPS secretions are key factors driving sedimentation differences. We further summarized current research progress on biofilm-MPs interactions, their applications, and limitations. Future research should focus on the following areas. Mechanistically, we should develop multiscale models that integrate biofilm dynamics with hydraulic conditions. Methodologically, we should advance in-situ observation techniques to quantitatively characterize biofilm properties such as EPS composition and community function. From an application perspective, we should explore bioremediation strategies that use functional microorganisms, such as specific algae or bacteria, to control MPs sedimentation.},
}
MeSH Terms:
show MeSH Terms
hide MeSH Terms
*Biofilms/growth & development
*Microplastics/metabolism/isolation & purification
Extracellular Polymeric Substance Matrix
*Water Pollutants, Chemical
Biodegradation, Environmental
Bacteria
RevDate: 2026-06-25
Effects of Ultrasound-Mediated Treatments on Dental Biofilm Attachment and Viability.
Ultrasound in medicine & biology pii:S0301-5629(26)00192-4 [Epub ahead of print].
OBJECTIVE: Dental biofilms are responsible for the majority of oral cavity diseases (e.g., caries, periodontitis and gingivitis). In this work, we evaluate the effects of therapeutic ultrasound on a Streptococcus mutans biofilm model. The research aim is to assess whether therapeutic ultrasound can be implemented in standard practice for the treatment and prevention of oral infections.
METHODS: Streptococcus mutans biofilms were grown on a tooth-mimicking substrate and subsequently exposed to chlorhexidine (CHX) and therapeutic ultrasound treatments. We examined the effects of low duty cycle (1%) 0.5 MHz ultrasound treatment at varying peak negative pressures (0.75-3.00 MPa) and CHX concentrations (0.025, 0.050 and 0.100 % w/V), both in the presence and absence of lipid-coated gas microbubbles.
RESULTS: Ultrasound treatment was effective at removing biofilm, particularly at peak negative pressures exceeding 2.25 MPa and in the presence of lipid-coated microbubbles as cavitation nuclei. Ultrasound exposure also resulted in improved bactericidal action of low-concentration CHX (0.050% w/V).
CONCLUSION: We demonstrated that 0.5 MHz therapeutic ultrasound treatment can be used for the mechanical removal of a fully formed and mechanically robust Streptococcus biofilm model. Although the ultrasound treatment alone did not reduce bacterial cell viability, its combination with low concentrations of CHX improved the antimicrobial treatment outcomes.
Additional Links: PMID-42350196
Publisher:
PubMed:
Citation:
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@article {pmid42350196,
year = {2026},
author = {De Grandi, D and LuTheryn, G and Stoffels, M and Born, M and Gottenbos, B and Carugo, D and Stride, E},
title = {Effects of Ultrasound-Mediated Treatments on Dental Biofilm Attachment and Viability.},
journal = {Ultrasound in medicine & biology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.ultrasmedbio.2026.05.008},
pmid = {42350196},
issn = {1879-291X},
abstract = {OBJECTIVE: Dental biofilms are responsible for the majority of oral cavity diseases (e.g., caries, periodontitis and gingivitis). In this work, we evaluate the effects of therapeutic ultrasound on a Streptococcus mutans biofilm model. The research aim is to assess whether therapeutic ultrasound can be implemented in standard practice for the treatment and prevention of oral infections.
METHODS: Streptococcus mutans biofilms were grown on a tooth-mimicking substrate and subsequently exposed to chlorhexidine (CHX) and therapeutic ultrasound treatments. We examined the effects of low duty cycle (1%) 0.5 MHz ultrasound treatment at varying peak negative pressures (0.75-3.00 MPa) and CHX concentrations (0.025, 0.050 and 0.100 % w/V), both in the presence and absence of lipid-coated gas microbubbles.
RESULTS: Ultrasound treatment was effective at removing biofilm, particularly at peak negative pressures exceeding 2.25 MPa and in the presence of lipid-coated microbubbles as cavitation nuclei. Ultrasound exposure also resulted in improved bactericidal action of low-concentration CHX (0.050% w/V).
CONCLUSION: We demonstrated that 0.5 MHz therapeutic ultrasound treatment can be used for the mechanical removal of a fully formed and mechanically robust Streptococcus biofilm model. Although the ultrasound treatment alone did not reduce bacterial cell viability, its combination with low concentrations of CHX improved the antimicrobial treatment outcomes.},
}
RevDate: 2026-06-25
Biofilm formation by Histophilus somni on 3D bovine respiratory tissue cultures.
Scientific reports pii:10.1038/s41598-026-57784-9 [Epub ahead of print].
The development of bacterial biofilms following infection involves bacterial attachment to tissues and maturation of the biofilm matrix (BM). However, studying the development of bacterial biofilms in vivo is difficult to follow. An established example of biofilm formation during host infection is bovine respiratory disease (BRD) due to Histophilus somni. To more accurately investigate in vivo biofilm development, three-dimensional bovine airway organoids comprised of bovine turbinate epithelial (BE) and pulmonary artery endothelial (BAE) cells embedded in type I collagen were developed. Cell-free concentrated culture supernatant (CCS) from biofilm-grown H. somni suppressed proliferation of epithelial cells more than endothelial cells, affected epithelial barrier integrity by disrupting ZO-1 localization, and induced robust IL-6 secretion in epithelial cells. The organoids were inoculated with H. somni to establish biofilms, which were examined by confocal laser-scanning microscopy of fluorescein-conjugated Moringa M lectin (specific for the exopolysaccharide of H. somni BM). Biofilm development progressed from attachment at day 3 to extracellular matrix elaboration enveloping BE and BAE by day 5. This organoid recapitulates key features of H. somni pathogenesis, such as barrier disruption, inflammatory signaling, and mature biofilm formation in relevant tissues. Thus, organoids provide a biologically relevant platform for mechanistic BRD studies and for evaluating vaccines or antimicrobials targeting biofilm-associated disease.
Additional Links: PMID-42350556
Publisher:
PubMed:
Citation:
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@article {pmid42350556,
year = {2026},
author = {Subhadra, B and Gandhi, N and Cao, D and Lee, YJ and Rajagopalan, P and Inzana, TJ},
title = {Biofilm formation by Histophilus somni on 3D bovine respiratory tissue cultures.},
journal = {Scientific reports},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41598-026-57784-9},
pmid = {42350556},
issn = {2045-2322},
support = {2200045, 24112389//National Science Foundation/ ; 2019-67015-29916//National Institute of Food and Agriculture/ ; },
abstract = {The development of bacterial biofilms following infection involves bacterial attachment to tissues and maturation of the biofilm matrix (BM). However, studying the development of bacterial biofilms in vivo is difficult to follow. An established example of biofilm formation during host infection is bovine respiratory disease (BRD) due to Histophilus somni. To more accurately investigate in vivo biofilm development, three-dimensional bovine airway organoids comprised of bovine turbinate epithelial (BE) and pulmonary artery endothelial (BAE) cells embedded in type I collagen were developed. Cell-free concentrated culture supernatant (CCS) from biofilm-grown H. somni suppressed proliferation of epithelial cells more than endothelial cells, affected epithelial barrier integrity by disrupting ZO-1 localization, and induced robust IL-6 secretion in epithelial cells. The organoids were inoculated with H. somni to establish biofilms, which were examined by confocal laser-scanning microscopy of fluorescein-conjugated Moringa M lectin (specific for the exopolysaccharide of H. somni BM). Biofilm development progressed from attachment at day 3 to extracellular matrix elaboration enveloping BE and BAE by day 5. This organoid recapitulates key features of H. somni pathogenesis, such as barrier disruption, inflammatory signaling, and mature biofilm formation in relevant tissues. Thus, organoids provide a biologically relevant platform for mechanistic BRD studies and for evaluating vaccines or antimicrobials targeting biofilm-associated disease.},
}
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In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.
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In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.
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ESP Picks from Around the Web (updated 28 JUL 2024 )
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Dinosaur tail, complete with feathers, found preserved in amber.
Astronomy
Mysterious fast radio burst (FRB) detected in the distant universe.
Big Data & Informatics
Big Data: Buzzword or Big Deal?
Hacking the genome: Identifying anonymized human subjects using publicly available data.