Search Results (695)

Chelerythrine (CHE) is a naturally occurring benzophenanthridine alkaloid obtained from plants such as Chelidonium majus L. It has received notable attention in pharmacology and microbial control because of its broad-spectrum activity and marked anti-inflammatory, apoptosis-inducing, and antibacterial effects. In this study, Bacillus tropicus, which frequently presents in the soil environment, was selected as the target microorganism to systematically examine the dose-dependent inhibitory influence of CHE on its growth curve, biofilm development, and survival rate. Furthermore, by simulating an antibiotic pressure environment in vitro, the original strain was subjected to continuous subculturing (30 times), and a highly drug-resistant B. tropicus strain capable of stable growth under high concentrations of CHE (300 mg/L) was successfully acclimated. After that, transcriptomics analysis was employed to compare the genetic differences between the wild-type bacterium and drug-resistant bacterium to determine how bacterial cells are able to resist CHE. A total of 868 genes in the CHE-resistant bacterium were revealed to be more active, while 539 genes were less active. These results indicate that the CHE resistance characteristics of the strain may be related to the adjustment of its sugar metabolism pathway and the biofilm formation pathway. As a widely used biological control bacterial strain, the successful acclimation of the B. tropicus strain with resistance to CHE has made it possible to use the combined formulation of these two agents for the prevention and control of plant diseases. Full article

Background: Multidrug-resistant (MDR) pulmonary infections represent a critical global health challenge, necessitating innovative therapeutic approaches. Green synthesis methodologies offer sustainable alternatives for nanoparticle fabrication while addressing antimicrobial resistance. Methods: Stimuli-responsive chitosan–silver hybrid nanoparticles (CS–Ag HNPs) were biosynthesized using Pseudomonas fluorescens bacterial extracts and loaded with ciprofloxacin for targeted pulmonary delivery. Comprehensive characterization included dynamic light scattering, transmission electron microscopy, UV–visible spectroscopy, and aerodynamic assessment via next-generation impactor. Antimicrobial efficacy was evaluated against MDR Pseudomonas aeruginosa and Klebsiella pneumoniae, including biofilm disruption studies, and biocompatibility was assessed. Molecular docking analysis elucidated binding mechanisms. Cytotoxicity and epithelial barrier integrity were evaluated using Calu-3 cell models. Results: The biosynthesized NPs exhibited optimal physicochemical properties (180 ± 20 nm, PDI 0.21 ± 0.04, ζ-potential + 32.4 ± 3.1 mV) with high encapsulation efficiency (68.2 ± 4.0%). Aerodynamic analysis revealed excellent inhalation characteristics (MMAD 2.6 μm, FPF 65 ± 5%). The hybrid system demonstrated 4-fold enhanced antimicrobial activity against MDR pathogens and significant biofilm disruption (70% for P. aeruginosa, 65% for K. pneumoniae) compared to free ciprofloxacin. Cell viability remained ≥85% at therapeutic concentrations. Molecular docking revealed enhanced drug-target binding affinity (−11.2 vs. −9.3 kcal/mol) and multi-residue interactions. Conclusions: Green-synthesized CS–Ag HNPs represent a promising sustainable platform for combating pulmonary MDR infections through enhanced antimicrobial efficacy and optimal aerodynamic properties. Full article

Antioxidant and microbiota in different mucosal sites of fish play important roles. However, relevant research is lacking for rice flower carp (Procypris merus). This study investigated antioxidant and microbiota characteristics across different mucosal sites (gill, skin, and intestine) of this fish. Antioxidant analysis revealed the following: catalase activity followed gill > intestine > skin (p < 0.05); total superoxide dismutase activity showed intestine > gill > skin (p < 0.05); malondialdehyde level in the gill significantly exceeded the skin and intestine (p < 0.05); and, superoxide anion level ranked gill > intestine > skin (p < 0.05). The intestinal microbiota had the significantly lowest α-diversity (p < 0.05). Across different mucosal sites, LEfSe analysis revealed differentially abundant genera, and microbial functional prediction (BugBase) showed significant differences in Forms Biofilms, Potentially Pathogenic, Stress Tolerant, and Gram-Positive (p < 0.05). Correlation analysis between differentially abundant genera and antioxidant indicators revealed multiple significant positive correlations (p < 0.05) but no significant negative correlations (p > 0.05) in the gill; only two significant negative correlations (p < 0.05) and no significant positive correlations (p > 0.05) in the skin; and no significant correlations (p > 0.05) in the intestine. Collectively, these findings might contribute to the microecological regulation of rice flower carp. Full article

Staphylococcus spp. present a dual role in cheese production as some species are pathogenic, while others bring beneficial characteristics. Coagulase-positive staphylococci (CoPS), particularly Staphylococcus aureus, are of concern due to their ability to produce enterotoxins linked to foodborne outbreaks. These toxins, encoded by staphylococcal enterotoxin (SE) genes, cause gastroenteritis, especially vomiting. Many members of the genus harbor a plethora of virulence genes and are able to form biofilms. The prevalence of antibiotic-resistant strains, including methicillin-resistant S. aureus (MRSA), complicates control. In contrast, some members of the coagulase-negative staphylococci (CoNS) group, such as Staphylococcus carnosus, Staphylococcus condimenti, Staphylococcus equorum, Staphylococcus piscifermentans, Staphylococcus succinus, and Staphylococcus xylosus, contribute to ripening, influencing flavor and texture. Some are even considered safe and studied for their ability to inhibit pathogens. Expression of enterotoxin genes in Staphylococcus, particularly S. aureus, is influenced by environmental factors and can be regulated by different mechanisms including quorum sensing. Understanding gene expression in conditions found during cheese production and ripening can help in formulating effective interventions. Risks posed by enterotoxin-producing Staphylococcus in cheese are evident, with numerous outbreaks reported worldwide. Moreover, several species present risks to both animal and human health. Effective control measures include adherence to microbiological criteria in foods, animal health monitoring, good manufacturing practices (GMP), temperature control, proper ripening conditions and hygiene. This review compiles and discusses existing knowledge on CoPS and CoNS in cheeses, providing a framework for evaluating their risks and benefits and guiding future studies in cheese microbiology. Full article

Background: Dalbavancin and oritavancin are long-acting lipoglycopeptides increasingly used off-label for a variety of Gram-positive infections. While their efficacy has been described in osteomyelitis, bacteremia, and infective endocarditis, evidence specifically addressing cardiovascular prosthetic infections such as prosthetic valve endocarditis (PVE), cardiac implantable electronic device (CIED) infections, left ventricular assist device infections (LVAD), and prosthetic vascular graft infections (PVGI) remains limited. These conditions are particularly challenging due to biofilm formation, difficulties in achieving surgical source control, and the frequent need for prolonged or suppressive therapy. Objectives: This systematic review aimed to summarize the available literature on the use of dalbavancin and oritavancin in cardiovascular prosthetic infections, with a focus on therapeutic strategies, clinical outcomes, and safety. Methods: We performed a systematic search of PubMed, Embase, Scopus, and Cochrane Library up to 24 June 2025 in accordance with PRISMA guidelines. Eligible studies included adults treated with dalbavancin or oritavancin for cardiovascular prosthetic infections. Data on study characteristics, population demographics, causative pathogens, and microbiological profiles, antibiotic regimens, treatment duration, use of therapeutic drug monitoring (TDM), indication or non-indication for chronic suppressive therapy, adverse events, clinical outcomes, and clinical efficacy were extracted. Results: Twenty studies comprising 113 patients were identified, of whom 111 received dalbavancin and 2 oritavancin. The main infections were PVE, CIED, LVAD, and PVGI. Dalbavancin was most effective as consolidation therapy after surgery or device removal, with high cure rates. Prolonged regimens were used as bridging or in partially treated cases, sometimes supported by TDM or PET/CT. Chronic suppressive therapy, mainly for LVAD and PVGI infections, achieved variable outcomes with relapses in about one fifth of patients. Adverse events were infrequent and generally mild. Conclusions: The included studies were highly diverse, conducted in various settings and with different objectives. Eight of the twenty included studies were single case reports on dalbavancin and oritavancin, highlighting the predominance of individual case descriptions in the available literature. Long-acting lipoglycopeptides may represent a valuable option for cardiovascular prosthetic infections. Their role appears most favorable as consolidation after adequate source control, while chronic suppressive use showed heterogeneous outcomes. This systematic review was registered on Open Science Framework. This work was supported by grants from the Italian Ministry of Health through Ricerca Corrente, Linea 3, Progetto 3. Full article

Pseudomonas aeruginosa is a Gram-negative, pathogenic, bacterium that produces biofilms comprising phenotypically distinct cell subpopulations. When separating and characterizing a single P. aeruginosa PA14 biofilm, three novel rugose small colony variants (RSCVs) (denoted RSCV_1, RSCV_2, and RSCV_3) were discovered. Characteristics of these stationary phase RSCVs differed between stationary phase wild-type (WT) PA14, between the PA14 biofilm subpopulations, and between the RSCVs themselves. The observed phenotypic changes in the RSCVs included differences in cellular morphology, exopolysaccharide production, biosynthesis of virulence factors, biofilm formation, and antibiotic tolerance. Stationary phase cell surface-associated molecules on the RSCVs were differently ionized as compared to WT PA14 using matrix-assisted laser desorption ionization (MALDI) mass spectrometry. Many RNA transcripts were differentially expressed between the RSCVs and WT PA14 as well as between RSCV_1 and RSCV_3. DNA sequencing revealed single-nucleotide deletions and single-nucleotide polymorphisms (SNPs) among the RSCVs and between the RSCVs and WT PA14. The levels of the intracellular signaling molecule bis-(3′,5′)-cyclic-dimeric-guanosine monophosphate (cyclic-di-GMP) were higher in the RSCVs compared to WT PA14 and significantly lower in RSCV_3 as compared to both RSCV_1 and RSCV_2. The detected differences in the RSCVs have significant implications for biofilm production, antibiotic tolerance, and virulence. Full article

Plasma surface modification has emerged as a powerful, versatile tool for tailoring the surface properties of biomedical devices and implants without altering the material characteristics in the bulk. This comprehensive review critically examines the current state-of-the-art in plasma-based surface engineering techniques, with a focus on enhancing biocompatibility, bio-functionality, and long-term performance of medical implants. The article systematically explores various plasma processes and their roles in modifying surface chemistry, topography, energy, and wettability. These alterations directly influence protein adsorption, cell adhesion, antibacterial activity, and corrosion resistance, all of which are crucial for successful clinical integration. Special emphasis is placed on the plasma treatment of metallic (e.g., titanium, stainless steel), polymeric (e.g., polytetrafluoroethylene, polyetheretherketone), and composite substrates commonly used in dental, orthopedic, and cardiovascular applications. This review also highlights synergistic strategies, such as plasma-assisted grafting of bioactive molecules and nanostructuring, that enable multifunctional surfaces capable of promoting osseointegration, mitigating inflammation, and preventing biofilm formation. Emerging trends such as atmospheric cold plasmas and the integration of plasma technology with additive manufacturing are outlined as promising future directions. By synthesizing insights from surface science, materials engineering, and biomedical research, this review provides a foundational framework to guide future innovations in plasma-treated biomaterials. It aims to inform both academic researchers and medical device developers seeking to optimize implant–tissue interactions and achieve improved clinical outcomes. Full article

Microbial fuel cell (MFC) is a novel and environmentally friendly technology for wastewater treatment and pollutant resource utilization. Although advances have been made in various aspects including electrode materials and synthetic biology approaches, the overall performance of MFC still requires improvement, with mass transfer efficiency and structural stability of biofilms emerging as key bottlenecks constraining their practical applications. This study investigated the regulation of substrate type and electrode potential during bioanode culture to optimize biofilm structure and enhance MFC performance. Results demonstrated that bioanodes cultured with glucose at −0.3 V formed vertically ordered biofilms that exhibited significant advantages in mass transfer characteristics, electrocatalytic activity, and structural stability. Under these culture conditions, enriched fermentative microorganisms facilitated the construction of porous biofilm scaffolds, while the electric field generated by the −0.3 V potential further induced vertical orientation and ordered arrangement of the biofilm. The superior mass transfer characteristics enabled the inner, middle, and outer layers of the biofilm to maintain high microbial activity (>50%), thereby maximizing the catalytic activity of electroactive microorganisms in each layer and enhancing biofilm structural stability. This study proposes a bioanode culture strategy centered on biofilm structural optimization, providing new theoretical foundations and technical pathways for achieving long-term stable and efficient MFC operation. Full article

The growing demand for functional foods has stimulated the search for novel microbial strains with probiotic potential, such as Veillonella atypica ATCC 17744, which has been emerging as a promising strain. Therefore, the present study aimed to perform an in vitro characterization of this strain, focusing on safety aspects and functional properties such as stress tolerance (pH, bile salts, and simulated gastrointestinal conditions), adhesion capacity (hydrophobicity, auto-aggregation, and biofilm formation), anti-pathogenic activity, antioxidant activity, antibiotic susceptibility, and enzymatic synthesis ability (gelatinase, lipase, catalase, and hemolytic activity). Stress tolerance assays revealed that this strain is sensitive to pH values below 4.00; however, no reduction in cell viability was observed at pH 3.00 in the presence of pepsin or 0.3% and 0.6% bile salts. Hydrophobicity testing showed moderate tolerance to toluene and low tolerance to xylene. Regarding biofilm synthesis, this strain formed a weak biofilm after 48 h of incubation. No anti-pathogenic activity was observed against Streptococcus aureus or Escherichia coli, and it exhibited low antioxidant activity in the DPPH assay. Regarding its safety properties, this strain was sensitive to all tested antibiotics and did not synthesize gelatinase, lipase, catalase, or exhibit β-hemolytic activity. Therefore, Veillonella atypica ATCC 17744 presents promising characteristics supporting its potential application in the development of functional food formulations, although further studies are required to ensure its safety for human consumption. Full article

The global sparkling wine market continues to grow steadily, reaching approximately 24 million hectoliters in 2023, with an annual increase of around 4% despite a general decline in overall alcoholic beverage consumption. This growth highlights the importance of employing diverse yeast strains to improve product variety and quality. Flor yeasts are specialized strains of Saccharomyces cerevisiae that develop a biofilm on the surface of certain wines during biological ageing. They possess unique physiological properties, including high ethanol tolerance and the capacity to adhere, which supports wine clarification. They also have the ability to contribute unique volatile compounds and aroma profiles, making them promising candidates for sparkling wine production. This study evaluated two flor yeast strains (G1 and N62), which were isolated from the Pérez Barquero winery during the second fermentation process using the traditional method. Sparkling wines were produced by inoculating base wine (BW) with each strain, and the wines were monitored at 3 bar CO₂ pressure and after 9 months of ageing on lees. Comprehensive metabolomic analysis was performed using GC-MS for volatile compounds and HPLC for nitrogen compounds, with statistical analysis including PCA, ANOVA, Fisher’s LSD, and correction FDR tests. Strain N62 demonstrated faster fermentation kinetics and higher cellular concentration, reaching 3 bar pressure in 27 days compared to 52 days for strain G1. Both strains achieved similar final pressures, 5.1–5.4 bars. Metabolomic profiling revealed significant differences in the profiles of volatile and nitrogen compounds between the two strains. G1 produced higher concentrations of 3-methyl-1-butanol, 2-methyl-1-butanol, and acetaldehyde, while N62 generated elevated levels of glycerol, ethyl esters, and amino acids, including glutamic acid, aspartic acid, and alanine. These findings demonstrate that both flor yeast strains successfully complete sparkling wine fermentation while producing distinct metabolic signatures that could contribute to unique sensory characteristics. This supports their potential as alternatives to conventional sparkling wine yeasts for enhanced product diversification. Full article

Periodontitis, a prevalent chronic infectious disease triggered by oral biofilm microbiota, results in progressive destruction of periodontal supporting tissues, and conventional treatments have limited therapeutic effects on it. Hydrogels, due to their excellent biocompatibility, three-dimensional extracellular matrix-like structure, and localized sustained-release properties, can provide support for cell attachment, promote cell proliferation and differentiation, and improve drug utilization efficiency, showing great promise for applications in treating periodontitis as well as promoting periodontal tissue regeneration. This article first introduces the limitations of current periodontitis treatments and the unique advantages of hydrogels in periodontitis treatment and periodontal tissue regeneration, and then provides an overview of the classifications of hydrogels, the active substances they can load, and the characteristics and functions of these active substances. Subsequently, the article introduces the latest advances in the application of several common natural polymer hydrogels in periodontal tissue regeneration. Finally, the article discusses the current limitations of hydrogels in terms of structure and properties, and proposes potential solutions and future development directions in periodontal tissue regeneration. Full article

The majority of Aeromonas strains are opportunistic pathogens for both humans and animals, causing a variety of diseases and posing a considerable risk to their health. In the current study, triploid cyprinid fish (TCF) were infected with a novel pathogenic Aeromonas sp. AS1-4 for pathological analysis. TCFs receiving Aeromonas sp. AS1-4 challenge exhibited oxidative damage in the liver and spleen, along with significant changes in immune-related gene expressions. Metabolomics assay indicated that strain AS1-4 challenge may exhibit a significant impact on metabolic processes of amino acids, with methylsuccinic acid (MSA) identified as vital biomarker. Following that, three potential probiotics designated Enterobacter strains fkY27-2, fkY84-1 and fkY84-4 were isolated from the intestine of TCFs, displaying excellent safety characteristics. In addition, intestinal Enterobacter strains exhibited multiple probiotic traits, including high degrees of hydrophobic activity, aggregation performance, biofilm-forming activity (BFA) and nutrient decomposing ability. Moreover, these probiotic isolates markedly coaggregated with Aeromonas sp. AS1-4 and Edwardsiella tarda 1l-4 and then suppressed their pathogenic biofilm-forming abilities, along with possessing robust antioxidant potential against various free radicals. These findings may provide valuable insights into metabolic response in fish post infection and health management in aquaculture. Full article

Background and Objectives: Orthodontic auxiliaries create plaque-retentive niches that may amplify biofilm accumulation and inflame adjacent soft tissues. While cross-sectional comparisons suggest higher palatal burden beneath acrylic elements, less is known about real-world patterns accumulated across years of routine care. We retrospectively evaluated periodontal and palatal outcomes, and, in a microbiology sub-sample, site-specific colonization, across three device types: molar bands, Nance buttons, and removable acrylic plates. Methods: We reviewed 2022–2025 records from a university orthodontic service, including consecutive patients aged 18–30 years with documented pre-placement and 6-month follow-up indices. Groups were bands (n = 92), Nance (n = 78), acrylic (n = 76). Standardized charted measures were abstracted: Plaque Index (PI), Gingival Index (GI), bleeding on probing (BOP%), probing depth (PD), and palatal erythema grade (0–3). A laboratory sub-sample (n = 174 visits) had archived swabs cultured for total aerobic counts (log₁₀ CFU/cm²) at the device, adjacent enamel, and palatal mucosa; Streptococcus mutans burden was available from qPCR (log₁₀ copies/mL). Results: Baseline characteristics were similar, except for longer wear at follow-up in Nance (10.1 ± 4.0 months) vs. bands (8.7 ± 3.2) and acrylic (6.9 ± 3.0; p < 0.001). At 6 months, device type was associated with greater worsening of PI and GI (both p < 0.001) and with higher palatal erythema (bands 0.7 ± 0.5; Nance 1.6 ± 0.8; acrylic 1.9 ± 0.7; p < 0.001). Microbiologically, palatal mucosal colonization was lowest with bands (3.3 ± 0.5), higher with Nance (4.9 ± 0.6), and highest with acrylic (5.0 ± 0.7; p < 0.001); S. mutans mirrored this gradient (p < 0.001). Palatal CFU correlated with erythema (ρ = 0.6, p < 0.001) and ΔGI (ρ = 0.5, p < 0.001). In adjusted models, acrylic (OR 6.7, 95% CI 3.5–12.8) and Nance (OR 4.9, 2.5–9.3) independently predicted erythema ≥2; recent prophylaxis reduced odds (OR 0.6, 0.3–0.9). Conclusions: In this single-center cohort, palate-contacting designs were associated with higher palatal biomass and erythema than bands. These associations support device-tailored hygiene considerations and proactive palatal surveillance, particularly for acrylic components. Full article

Drinking water pipe biofilms, comprising viable microorganisms, microbial residues, and organic/inorganic particulates, pose significant risks to water safety by promoting the proliferation of opportunistic pathogens, pipe corrosion, and degradation of water quality. Their formation is strongly influenced by environmental conditions within the piping system. However, there is a lack of systematic research investigating the potential correlations between biofilm microbiota and the oral microbiomes of intensively farmed swine, as well as the age-dependent regulatory mechanisms shaping aquatic microbial communities. This pioneering study conducted a comparative analysis of biofilm microbiota from swine house water pipes and oral microbiomes across three growth stages (30-day BBF, 70-day NBF, and 110-day FBF groups), yielding three key findings. First, the biofilm biomass and dominant bacterial genera (e.g., Brevibacterium in BBF vs. Brevundimonas in FBF) exhibited stage-specific variations associated with swine age. Second, while the oral microbiomes showed no significant taxonomic divergence at the phylum or genus level, they shared characteristic phyla, including Actinobacteria and Bacteroidetes, with pipe biofilms, indicating potential cross-habitat microbial interactions. Third, the antibiotic resistance gene (ARG) adeF was consistently detected at high prevalence across all biofilm groups. These findings offer new insights into microbial transmission dynamics and inform risk mitigation strategies for livestock water supply systems. Full article

Methicillin-resistant S. aureus (MRSA) possesses broad resistance, biofilm formation, and high virulence characteristics. Therefore, developing new therapeutic strategies against this pathogen is urgent. This work reports kaempferol (kol) and kaempferin (kin) bound to the active site of β-lactamase and interacting with key residues, thereby inhibiting its activity. In addition, kol and kin reduced the secretion of β-lactamase to the external environment, then the shielding effect of β-lactamase to β-lactam antibiotics was weakened, and finally, the bactericidal ability of ampicillin (Amp) to MRSA was enhanced. Kol and kin relieved the inflammatory responses of J774 cells induced by MRSA and improved the survival of Galleria mellonella (G. mellonella) infected by MRSA when combined with or without Amp. These data suggest that kol and kin have the potential to be developed as anti-MRSA infection agents, which would broaden the application prospects of these compounds. Full article