Archives of Microbiology最新文献

Cervical carcinoma continues to be one of the leading causes of cancer-related mortality among women worldwide, disproportionately striking developing regions, including India. High-risk persistent HPV infection has long been recognized as the central etiological factor in cervical carcinogenesis; however, not all infected women end up with malignancy, indicating the role of viral genomic variation and host genetic susceptibility. High-risk HPV variants, primarily comprising lineage clusters of HPV16 and HPV18, exhibit differential oncogenic potential due to mutations in the E6/E7 oncogenes and the LCR, which is responsible for viral persistence, the efficiency of p53/pRb degradation, immune evasion, and epithelial cell transformation. Genetic polymorphisms in the host regulate the natural history of infection and cervical cancer risk. Variants of HLA class I/II alleles influence antigen presentation and Single nucleotide polymorphism in immune regulatory cytokine genes (IL-10, TNF-α, IFN-γ), TP53 codon 72 (Arg/Pro), DNA repair and metabolic genes (XRCC1, MTHFR), and detoxification gene null genotypes (GSTM1, GSTT1) modulate viral persistence, oxidative DNA damage response, and oncogenic progression. Advancements such as next-generation sequencing and immunogenetics, which identify the relationship between HPV variants and host immune genes that modulate disease susceptibility, vaccine responsiveness, and progression patterns across various genetic backgrounds. This review systematically integrates molecular mechanisms of HPV variant-induced oncogenesis and host genetic susceptibility with emphasis on population-based variability in addition to evidence culled from meta-analyses and GWAS data for immune regulation, DNA repair, as well as host single nucleotide polymorphisms in different populations and its implications for personalized prevention measures, screening, and vaccine response.

The emergence of Carbapenemase-producing Klebsiella pneumoniae (CP-KP) strains is becoming a significant global concern. Rising resistance rates in these strains significantly impact available treatment options. Therefore, this present research aims to identify the existence of antibiotic-resistance genes in clinical isolates of CP-KP strains. Whole-genome sequencing data from 17 CP-KP isolates were analyzed to identify genetic variants associated with antibiotic resistance. Among the 85 variants, a deleterious mutation, E466D, was identified in DNA gyrase B (GyrB), associated with fluoroquinolone (FQ) resistance. Therefore, flavonoids were used to target mutated GyrB. Flavonoids have been extensively investigated for their antibacterial properties, as they tend to inhibit the growth of many pathogenic microorganisms, including multidrug-resistant bacteria. A total of 222 flavonoids were subjected to virtual screening against the GyrB. The docking affinity of all the ligands with GyrB was within the range of − 3.7 to − 7.9 kcal mol^− 1. Further, the top 10 compounds having stronger docking energy compared to the reference compound (− 6.1 kcal mol^{− 1}) were subjected to MD simulation in triplicate for 250 ns to examine the ligand’s stability against GyrB. Out of the 10 compounds, five compounds, namely, theaflavine, neobavaisoflavone, trifolirhizin, isosilybinin, and glycitin, showed good stability. Identification of natural compounds with high binding affinity for mutated GyrB indicates that they may be used as innovative therapeutic treatments. This finding might serve as a foundation for upcoming investigations and clinical studies aimed at creating potent remedies treating infections caused by K. pneumoniae that are resistant to FQ.

The development of resistance to antibiotics and bacteriophages highlights the necessity of alternative therapy for Staphylococcus aureus. This study aimed to explore the utility of temperate phages as a biocontrol agent against multidrug-resistant (MDR) S. aureus. Four S. aureus temperate phages were successfully isolated, and their biological features, genomic properties, and antibacterial effect against S. aureus and biofilm were characterised. Phage SapYZUs891 exhibited relatively high titre (1.7 × 10¹⁰ PFU/mL), short latent period (5 min), large burst size (554 PFU/cell), strong pH (4–10) and thermal stability (25–70 °C), and a broad lytic spectrum (47.3%, 43/91; p ≤ 0.05). Comparative genomic analysis suggested that SapYZUs891 lacks antibiotic resistance or virulence genes, but contains unique gene content, including genes encoding DNA polymerase, DNA packaging protein, holin, and tail fibre protein. Notably, SapYZUs891 significantly inhibited biofilm formation (28.3%—70.6%, p < 0.01), scavenged mature S. aureus biofilms (36.9%—61.5%, p < 0.001) and reduced the counts of S. aureus (1.14 – 1.40 Lg CFU/mL, p ≤ 0.01) in milk at 4°C. Furthermore, SapYZUs891 effectively reduced the minimum inhibitory concentrations of MDR S. aureus against antibiotics by 2 – 64 folds (p ≤ 0.05). Therefore, the temperate phage SapYZUs891 with attractive biological properties, genetic features and antibacterial potential is an effective biocontrol agent against MDR S. aureus.

Solid‑state fermentation was optimized using Aspergillus niger ISL‑09 and Bacillus subtilis 01‑21 with orange peel as substrate for pectin lyase production. The optimal conditions were: substrate level 10 g, moisture content 25 mL for A. niger and 5 mL for B. subtilis, inoculum size 10%, and incubation times of 72 h and 48 h, respectively. These conditions gave enzyme activities of 2.45 U/mL (A. niger) and 1.61 U/mL (B. subtilis). Partial purification by 80% ammonium sulfate precipitation followed by dialysis increased specific activities to 7.4 U/mg and 7.0 U/mg, with recovery yields of 76.13% and 70.24%, respectively. Enzyme characterization showed optimal activity at 60 °C (pH 8.0) for A. niger and 50 °C (pH 8.5) for B. subtilis. SDS and EDTA enhanced activity at 2.5 mM and 2.0 mM, respectively. Both enzymes retained substantial activity for up to 30 min before declining due to thermal or temporal denaturation. When applied to in situ corn‑oil extraction, the enzymes outperformed untreated controls, achieving extraction yields of 15.2% (A. niger) and 10.72% (B. subtilis). In‑silico docking of modeled 3D structures identified key catalytic residues Asp154, Arg176, and Arg236 in A. niger pectin lyase that bind galacturonic acid. PatchDock simulations showed favorable ligand‑enzyme interactions and stable clustering, supporting high catalytic potential. This integrated approach demonstrates the feasibility of using microbial pectin lyase for sustainable, cost‑effective oil extraction, offering both experimental and molecular insights for future biocatalyst development in biorefinery platforms.

Vibrio parahaemolyticus is a foodborne pathogen that can cause severe gastroenteritis. After entering the human intestine through contaminated seafood (1.00% NaCl) V. parahaemolyticus will encounter a physiologically related dual pressure environment: low salinity and elevated bile salts (0.03%-0.30%). Although bile salts can affect V. parahaemolyticus under optimal salinity conditions (3.00% NaCl), little is known about their effects on paralysis under low salt conditions (0.90% NaCl) in the intestinal stress environment. This research uniquely simulated this intestinal niche using 0.90% NaCl-0.10% bile salts, revealing its effects on growth kinetics, motility, biofilm formation, and transcriptome responses. The main findings include: significant inhibition of growth (prolonged the lag time (LT)), decreased the maximum specific growth rate (µ_max)), swimming ability, and biofilm formation; But it enhances the ability to swarming; And unique transcriptome reprogramming. In addition, transcriptome sequencing revealed that swarming related genes, biofilm related genes, and T3SS virulence genes were significantly down regulated, while iron metabolism and swimming related genes were significantly up-regulated. It is crucial that KEGG enrichment indicates that the ribosomal pathway may be the central regulatory hub for observed biofilm and motility inhibition. This research provides the first comprehensive analysis of the effects of bile salts on intestinal related low salinity, providing important insights into the intestinal adaptation and pathogenic mechanisms of V. parahaemolyticus.

Foodborne Clostridium spores represent a significant group of pathogens that threaten food safety, posing a unique control challenge due to their extreme resistance to conventional processing and high pathogenicity upon germination. The spore inner membrane (SIM), a critical structure enveloping the spore core, serves as the central functional interface governing resistance, dormancy maintenance, and germination regulation. Notably, the composition and organization of the Clostridial SIM exhibit distinct features compared to the well-studied Bacillus model, though some mechanistic understandings are extrapolated from the latter. Critically, the SIM lipids in dormant spores exist in a tightly packed gel phase, which drastically reduces membrane fluidity and constitutes the fundamental physical basis for its exceptional low-permeability barrier. Current debates center on whether key germination receptors are individually embedded within the SIM or assemble into a higher-order “germinosome” complex that may span or sit atop the membrane to coordinate signal perception. This article systematically reviews the research progress on the composition, structure, and functional characteristics of the SIM in foodborne Clostridial spores. It elaborates on the low-permeability barrier and signaling hub formed by its unique phospholipids (e.g., cardiolipin, phosphatidylglycerol) and functional proteins (e.g., Ger family receptors, SpoVA channels). The core roles of the SIM in resisting heat and chemical stress, maintaining core homeostasis, and responding to germination signals are analyzed. Furthermore, key research techniques in this field (e.g., electron microscopy, solid-state NMR, lipidomics / proteomics, gene editing) and their applications are summarized. Finally, current challenges and bottlenecks are outlined, including difficulties in dynamic analysis of the SIM, understanding interspecies mechanistic differences, and developing targeted control applications. This review aims to deepen the understanding of the resistance and germination mechanisms of Clostridial spores and to provide a insight and a potential theoretical basis for developing more targeted spore-control strategies targeting the SIM.

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Solar-powered hydroponics farming of edible crops is gaining prominence as a sustainable cultivation method. However, growing evidence indicates a significant risk of pathogen emergence in commercial settings, potentially arising from waterborne sources or plant physiological stress. Nevertheless, there is a paucity of understanding the potential of plant-growth promoting and biocontrol traits among microorganisms colonizing the rhizosphere of hydroponically grown crops. In this study, we investigated the culturable rhizosphere microbial communities of three different Lactuca sativa cultivars in controlled green-house hydroponics employing the circulating nutrient-film farming technique with coconut coir as substrate. Over an 8-week growth period, ~ 250 bacterial and fungal strains were isolated. By week 7, the presence of Alternaria sp. SSSB_F2 and Fusarium sp. SSSB_F1 was detected from infected leaves and confirmed to be pathogenic to all L. sativa cultivars. Notably, fungal infections were accompanied by a marked decline in cultivable rhizosphere microbes, suggesting a disruption of root-associated microbial communities. Further, biochemical characterisation of rhizosphere strains followed by 16SrRNA and ITS sequencing led us to identify eight promising biocontrol and plant-growth promoting bacterial strains belonging to Stenotrophomonas, Bacillus, Pseudomonas, Micrococcus, Exiguobacterium, Staphylococcus, and two fungal strains as Trichoderma and Simplicillium. A plant-probiotics consortium was thus formulated based on mutual compatibility and tested for its effects on seedling germination, plant development, and pigmentation. Preliminary trials performed using this consortium to prime L. sativa seeds enhanced seedling germination and plant growth in coconut coir. These findings underscore the importance of harnessing beneficial rhizosphere microbiota enriched during controlled environment agriculture, such as hydroponics, and their potential to enhance plant-growth as well as disease resilience.

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Verticillium wilt is one of the most devastating diseases of cotton, yet effective biocontrol strains remain scarce. This study aimed to guide the selection of efficient biocontrol strains by comparing the microbiomes of healthy and diseased cotton plants. Our results revealed that Verticillium dahliae V991 (V991) significantly altered the bacterial and fungal communities in the cotton roots, rhizosphere soil and bulk soil. Compared to diseased cotton in the V991 inoculation group (D), both healthy cotton in the V991 inoculation group (H) and non-inoculated control cotton (C) suppressed Verticillium and Fusarium and enriched Bacilli, Clostridia, Archacosporales, Glomerales, unclassified Basidiomycota and unclassified Glomeromycota in the roots, enriched Burkholderiales in the rhizosphere soil, enriched Archaeosporales and Verrucomicrobiota in the bulk soil. A total of 20 strains with antagonism against V991 were screened, most isolated from roots of the C group. Bacillus amyloliquefaciens M9 (BM), isolated from rhizosphere soil, exhibited the strongest antifungal activity, while Bacillus cereus R19 (BR), isolated from root, showed weaker activity. Pot experiments demonstrated that application of BR and BM (10⁹ CFU/mL) reduced disease incidence by 44.82% and 24.14%, respectively, compared to the control. Field experiments showed that BR reduced disease incidence by 88.46%, while BM achieved a 50.01% reduction. These findings confirm that comparative microbiome analysis is a powerful strategy for selecting highly effective biocontrol strains.

Despite significant advancements in chemotherapy, treatment efficacy remains limited by drug resistance and toxicity. Anticancer agents from natural sources have been proven in terms of potency, efficiency, and safety. Among them, fungi have emerged as the largest contributor to the field of medicine. However, many fungal bioactive compounds remain underexplored due to their structural and ecological diversity. This review highlights the research progress on products, functions, and therapeutic mechanisms of anticancer fungi identified during 2015–2025. Furthermore, this review provides a novel integrative perspective by comprehensively comparing three diverse categories of fungi, including endophytic, marine and edible fungi. Although various anticancer metabolites have been reported from edible and marine fungi, only a few have reached the market primarily due to low metabolite yields and limited clinical, toxicity, and pharmacokinetic data. This review focused on the most potent anticancerous metabolites, fungal extracts and their biological activities from 3 categories of fungi against the common cancer cell lines, indicating endophytic fungi as the biggest source of anticancerous metabolites. Anticancer mechanisms involved are the production of ROS, damage to mitochondrial membrane, inhibition of microtubule formation, caspase 3/9 pathway activation, and macrophage-based actions.

Triple-negative breast cancer represents a significant therapeutic challenge due to its aggressive behavior and limited treatment options. This study investigates the anticancer potential of microcin H47 (MccH47), a bacteriocin derived from clinical Escherichia coli isolates, against this malignancy. Among 120 screened Enterobacteriaceae isolates, 25 exhibited antimicrobial activity, with isolate 58 confirming MccH47 gene expression through molecular analysis. Cell viability assessment revealed a concentration-dependent reduction in cancer cell survival, while cell death analysis demonstrated approximately 86% apoptosis following 48 h of treatment. Gene expression studies identified significant downregulation of BCL2 and STAT3, indicating involvement of the STAT3/BCL-2 pathway in the observed effects. The extract exhibited biocompatibility toward normal fibroblasts, emphasizing MccH47’s dual antimicrobial and antitumor properties with notable therapeutic selectivity. These findings support further development of MccH47 as a novel therapeutic agent for breast cancer treatment.

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