Folia microbiologica最新文献

A recently discovered source for infection of slaughter pigs, and thus entry for bacteria into the food chain, is the installed drinking equipment in lairage pens of pig abattoirs. To mitigate this, nano-coating of stainless steel, currently used in human medicine fields as well as in other parts of the food chain, appears as promising technology. In this study, silicon dioxide nano-coating was applied to six drinkers and installed for one and three months in a lairage of a pig abattoir, while results were compared with those of drinkers that had not been nano-coated. Laboratory examination of eight sample types related to the drinkers was conducted for total aerobic plate count, Enterobacteriaceae count, Pseudomonas spp. count, Salmonella presence, pathogenic Yersinia enterocolitica presence, Listeria monocytogenes presence and methicillin-resistant Staphylococcus aureus presence. The nipple drinker, which the pigs take into their mouth for drinking, was then examined using scanning electron microscopy and elemental analysis. The nano-coating did not produce statistically significant reductions in the loads or presence of these bacteria compared to the same but uncoated drinking equipment used under the same conditions. Further studies should focus on the implementation of combined methods, such as nano-coating and sanitary treatment, as well as modifications to the coating itself, to produce meaningful reductions of the bacterial loads on/in abattoir lairage drinking equipment.

Antibiotic-resistant microorganisms are a major concern for researchers, medical experts, and public healthcare workers. Healthcare organizations, particularly wastewater from hospitals, can pose a significant global health risk if wastewater treatment (WWT) strategies are inadequate or suboptimal. This review article focuses on antibiotic-resistant microorganisms and virulence factors found in microbial contaminants of hospital wastewater. In this review, we synthesize findings from a wide range of studies examining antibiotic resistance and virulence factors of microorganisms in hospital wastewater, highlighting the critical public health challenge posed by microbial contamination in healthcare environments. The rise of drug-resistant bacteria represents a severe threat to global health since ailments arising from these organisms are becoming more challenging to cure. Understanding the virulence mechanisms of the aforementioned diseases is essential for developing potent disease-effective prevention and counter-measure strategies. Analysis of hospital effluents reveals a variety of virulence factors, emphasizing the prospective health risks linked with wastewater pollution. The surrounding and societal influence on the well-being of hospital waste underscores the urgent need to develop and implement robust medical waste management and wastewater treatment protocols. This study reviews various treatment technologies aimed at mitigating antibiotic resistance in hospital wastewater, underscoring the importance of comprehensive approaches to curb the spread of drug-resistant bacteria. The insights provided are crucial for improving wastewater management practices to protect public health and prevent the widespread distribution of resistance to antibiotics.

The increasing prevalence of neurodegenerative diseases is a formidable task due to their multifactorial causation and treatments limited to disease maintenance and progression. Epstein-Barr virus (EBV) is reported to be involved with neuropathologies; previous studies from our group suggested the effective binding of epigallocatechin-3-gallate (EGCG) with EBV nuclear antigen 1 (EBNA1) and glycoprotein H (gH). Therefore, in the current study, we evaluated the anti-EBV effect of ECGG on the neuronal cells. EBV-GFP exhibited a decline after EGCG treatment. We have observed a decrease in specific latent and lytic cycle genes. EBNA1 unravelled attenuation at day 1 (D1), whereas EBNA3B, EBNA3C, BMRF1, BZLF1, and gp350 showed major downregulation in D3 compared to EBV infection. Notably, EBNA-LP has shown mitigation in both the considered time points. Inflammatory and chemokine moieties like IL-6, CCR1, CCR3, and CCR5 declined upon EGCG treatment, while IL-10 exhibited elevation. Transcription factor STAT3 and NF-kB were decreased, especially in the pre-EGCG treated samples. Subsequently, restoration in the mitochondrial membrane potential was observed after EGCG treatment. We observed an increase in the mitochondrial fission genes like DRP1 and MiD49, and not many regulations were observed in the mitochondrial fusion genes except MFN2. Furthermore, the CytC, CytC oxidase, MAVS, ANT, and SDH exhibited elevation upon EGCG treatment, while ATPsyn and ABAD showed downregulation. Dysfunction of mitochondria is further related to apoptosis of neurons. Herein, we were keen to examine the level of amyloid-precursor protein (APP), and it has also indicated declined after EGCG treatment. Altogether, the current study demonstrated the anti-EBV effect of EGCG by subsiding the EBV-mediated inflammation and amendments in the neuropathological markers.

The healthcare sector is currently concerned about infections caused by Porphyromonas gingivalis biofilms due to their high frequency and incidence, particularly in patients with implanted medical devices. This study investigated biofilm formation and biofilm-related gene expression in P. gingivalis on titanium-copper discs and polycarbonate discs. P. gingivalis highly expressed biofilm-related genes were examined using quantitative real-time PCR during biofilm formation on the Ti-Cu surface. SEM analysis revealed various cellular components around the aggregated cells at various stages of biofilm formation. The Ti-Cu surface was colonized by P. gingivalis, as evidenced by biofilm formation levels that varied from ~ 10³-10⁴ CFU/cm² after 2 days of incubation to ~ 10⁵-10⁷ CFU/cm² after 7 days. Real-time expression analysis showed a significant increase in the expression of signaling molecules on Ti-Cu discs. Furthermore, genes linked to virulence (rgpA, rgpB, and Kgp, fimC, PorK, and PorP) and adhesion (mfa1, fimD, fimA, RpoN, rgpA, rgpBiKgp) demonstrate transcriptional alterations in signaling pathways impacting P. gingivalis biofilm on Ti-Cu surfaces. Scanning electron microscopy (SEM) and confocal microscopy correlated the results of the structural analysis with the expression from the qPCR data. This study adds significant value by advancing the understanding of biofilm formation on Ti-Cu implants.

Dahi, a traditional yet underexplored fermented milk product from Pakistan, harbors diverse lactic acid bacteria (LAB) that have potential as probiotics. These bacteria could be used for therapeutic purposes, beneficial modulation of gut microbiota, and in the formulation of functional foods and feeds. This study aimed to isolate and characterize probiotic LAB from dahi, assess their survival in simulated gastrointestinal conditions, and evaluate their safety and probiotic potential, both phenotypically and genotypically. A total of 143 isolates from 37 samples were evaluated for probiotic traits, including acid and bile tolerance, antibacterial activity, cholesterol-lowering capacity, and antioxidant activity. The strains were also tested for antibiotic sensitivity and safety through in vitro tests and genomic analysis. A multi-strain probiotic consortium was developed and tested for enhanced functionality. Out of 143 isolates, 62 LAB strains were identified. These strains demonstrated significant survival under acidic (pH 2) and bile conditions. Antibacterial activity against pathogens ranged from 51 to 88%. The strains exhibited high cholesterol removal (up to 98%) and antioxidant activity (up to 76%). Genomic analysis revealed the presence of key probiotic-related genes, including those for acid resistance, bile salt hydrolase, and adhesion. All strains were sensitive to EFSA-recommended antibiotics and exhibited no hemolytic or DNase activity, confirming their safety. The multi-strain consortium showed superior probiotic potential and survival in simulated gastrointestinal conditions. LAB strains isolated from dahi possess strong probiotic potential, confirmed through in vitro and genomic safety assessments. The multi-strain consortium holds promise for applications.

Lipases are among the most significant biocatalysts that constitute the third most important group of enzymes due to their vast range of applications. The present research represents the first attempt to optimize the growth medium constituents to increase the production of recombinant lipase in Pseudomonas aeruginosa SDK-6. One factor at a time (OFAT) revealed castor oil, yeast extract, and ammonium nitrate as the most significant medium components affecting the recombinant lipase production. Further optimization via response surface methodology (RSM) resulted in lipase production of 115.50 U/mL with 0.5% (v/v) castor oil, 0.2% (w/v) yeast extract, and 0.1% (w/v) ammonium nitrate at pH 7. Statistical validation of the observed value via ANOVA revealed an F value of 117.02 at p < 0.01, with an R² of 0.9909. An overall 3.58-fold lipase production was achieved after optimization via OFAT and RSM. The purified lipase exhibited a specific activity of 102.73 U/mg, and the molecular mass was deduced to ~ 19.5 kDa via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum temperature and pH for the recombinant lipase activity were 40 °C and 10, respectively. The enzyme retained most of its initial activity up to 32 h when incubated at an elevated temperature of 40 °C. The purified enzyme also exhibited stability over alkaline pH, with remarkable stability at pH 12. The enzyme activity was enhanced in the presence of CaCl₂, MgCl₂, FeCl₂, NaCl, methanol, dichloromethane, and Triton X-100. The enzyme also retained most of its initial activity in the presence of all other screened organic solvents.

Mangrove forests support robust microorganisms due to their changing temperature and salinity conditions. Tropical yeasts isolated from such habitats have the potential to produce clinically significant enzymes like L-asparaginase. L-asparaginase converts L-asparagine to L-aspartate and ammonia. In this study, 14 tropical yeasts were isolated from mangrove sediments collected from Madkai, Goa, India. From these, on screening with two different indicator dyes phenol red and bromothymol blue, five isolates were positive for L-asparaginase enzyme as indicated by rapid plate assay technique. Isolate having highest enzyme activity was identified as belonging to genus Cyberlindnera. The study of effect of physical parameters on enzyme production revealed optimal incubation time of 48 h, pH of medium 7.0 and incubation temperature of 28 °C. Evaluation of carbon and nitrogen sources indicated L-asparagine as sole nitrogen source and glucose as carbon source achieved maximum enzyme production. L-Asparaginase activity of isolate GULAMMS8 under optimal medium composition and parameter conditions that are glucose as carbon source with L-asparagine as sole nitrogen source and pH of 7.0, an incubation temperature of 28 °C showed a two-fold increase, while the incubation period was halved. This work is a primary study on L-asparaginase producing tropical mangrove yeast belonging to genus Cyberlindnera aiming to understand the influence of physical factors and nutrient sources on enzyme production.

The human oral microbiome is a complex, dynamic ecosystem critically involved in maintaining oral health and contributing to systemic well-being. Many bacteria and fungi are involved in oral cavities such as Penicillium, Rhodotorula, Saccharomycetales, Streptococcus, Veillonella, Neisseria, Actinomyces, and Schizophyllum. Disruption of microbial homeostasis, or dysbiosis, underpins a wide spectrum of oral diseases, including dental caries, periodontal disease, endodontic infections, and mucosal conditions. Recent advances in microbiome research have elucidated the mechanisms by which pathogenic microbial consortia, such as the red complex (Porphyromonas gingivalis, Tannerella. forsythia, and Treponema denticola), synergistically promote disease progression through virulence factors, metabolic interactions, and biofilm formation. Emerging microbiome-based therapies, comprising probiotics, postbiotics, predatory bacteria, and using bacteriophages, offer promising adjuncts or alternatives to traditional antimicrobial approaches by restoring microbial balance, reducing pathogenic load, and modulating host immune responses. For instance, probiotic strains like Streptococcus salivarius and Lactobacillus spp. have demonstrated efficacy in reducing plaque, gingival inflammation, and pathogenic bacteria, as well as having significant immunological modulation, while postbiotics provide similar benefits with enhanced safety and stability. Additionally, predatory bacteria such as Bdellovibrio bacteriovorus show potential for selective bacterial elimination and combating periodontal diseases that are driven by Gram-negative anaerobes. Bacteriophages offer another precision tool for targeting oral pathogens by lysing bacteria upon replication. Finally, oral microbiota transplantation aimed at treating periodontal disease by restoring a balanced microbial community in the oral cavity. These innovative strategies, combined with a nuanced understanding of biofilm dynamics and host-microbe interactions, pave the way for personalized and ecologically sustainable oral health interventions. Continued research is essential to translate these promising approaches into clinical practice, optimize delivery systems, and elucidate long-term safety and efficacy.

Human metapneumovirus (hMPV) co-infections with viral and bacterial pathogens are increasingly recognized as major contributors to severe respiratory disease, especially in children, older adults, and immunocompromised individuals. This review summarizes current knowledge of hMPV co-infections with respiratory viruses (e.g., hRSV, influenza, SARS-CoV-2) and bacteria (e.g., Streptococcus pneumoniae, Haemophilus influenzae), highlighting both shared and distinct pathogenic pathways. Viral co-infections often intensify inflammation through prolonged replication and type I interferon (IFN) suppression, whereas bacterial co-infections exploit epithelial injury and mucin overproduction to enhance adhesion, biofilm formation, and antimicrobial resistance. Converging mechanisms include epithelial disruption and IL-6/TNF-α-driven cytokine dysregulation, both of which contribute to worsened outcomes. A structured literature search of PubMed, Scopus, and Web of Science identified studies on hMPV co-infections, immune responses, and clinical outcomes. The novelty of this review lies in its comparative perspective, distinguishing viral from bacterial interactions to clarify overlapping versus pathogen-specific mechanisms. Clinically, this distinction informs diagnostics, highlights gaps in therapeutic strategies, and emphasizes the need for targeted interventions to reduce the burden of severe hMPV-associated respiratory disease.

In recent decades, there has been a growing interest in harnessing plant growth-promoting rhizobacteria (PGPR) as a possible mechanism to mitigate the environmental impact of conventional agricultural practices and promote sustainable agricultural production. This study investigated the transferability of promising PGPR research from maize to another Poaceae cereal crop, wheat. This multi-seasonal study evaluated the wheat grain yield effect of Lysinibacillus sphaericus (T19), Paenibacillus alvei (T29) when applied i. individually, ii. as a consortium with Bacillus safensis (S7), and iii. at a 75% reduced fertilizer rate. Whole genome sequencing allowed annotation of genes linked to plant growth promotion, providing potential genomic explanations for the observed in-field findings. Application of the consortium compared to a commercial PGPR showed significantly increased wheat yield by 30.71%, and 25.03%, respectively, in season one, and 63.92% and 58.45%, respectively, under reduced fertilizer rates in season two. Individual application of T19 and T29 showed varying results, with T19 increasing wheat yield by 9.33% and 16.22% during seasons three and four but a substantial reduction (33.39%) during season five. T29 exhibited yield increases during season three (9.31%) and five (5.61%) but led to a significant reduction (21.15%) in season four. Genomic analysis unveiled a spectrum of plant growth-promoting genes including those associated with ammonification, phosphate solubilization, ethylene, siderophore, catalase, and superoxide dismutase production. These findings offer valuable insights into the mechanisms behind observed field results, with potential implications for advancing sustainable agriculture and crop productivity in evolving agricultural landscapes.