Frontiers in Microbiology最新文献

While probiotics like Enterococcus faecium are known for gut health benefits, their potential anti-aging effects are poorly understood. This study investigated whether E. faecium fermentation broth delays aging and explored its mechanisms. Using a mouse model, lifespan assays suggested that the E. faecium fermentation broth may contribute to lifespan extension, indicating anti-aging properties. Microbiome analysis showed it modulated gut microbiota, increasing beneficial Akkermansia abundance. Key active components identified included myo-inositol (promoting hair follicle growth), D-ribose, and secreted proteins. While myo-inositol increased the abundance of Lactobacillus reuteri and Lactobacillus johnsonii, it did not increase Akkermansia. A high-content secreted protein, NlpC/P60, present in E. faecium fermentation broth, may enhance host immunity through the NOD-like receptor signaling pathway, thereby restricting pathogen colonization and reshaping the gut microbiota. This immune boost indirectly elevated levels of beneficial bacteria like Akkermansia muciniphila and L. johnsonii, improving overall microbiota composition and mitigating age-related diseases. The findings demonstrate that E. faecium fermentation broth combats aging through multiple pathways, primarily microbiota modulation and immune enhancement. The identification of NlpC/P60 as a key mediator provides crucial mechanistic insight. This study elucidates the material basis and pathways by which E. faecium fermentation broth delays aging, offering experimental support for developing novel microecological therapies against age-related diseases.

Orchids, one of the most diverse and ecologically important plant families, form complex associations with endophytic microorganisms that are vital for their survival, growth, and adaptation. These endophytes, including both fungi and bacteria, inhabit orchid tissues without causing harm and contribute to key physiological processes such as nutrient acquisition, stress tolerance, and disease resistance. This review explores the diversity and ecological roles of orchid-associated endophytes, emphasizing their significance in promoting germination, biomass production, and resilience to environmental stressors. Plant Growth-Promoting Bacteria (PGPB) such as Pseudomonas, Bacillus, and Burkholderia enhance nutrient uptake and plant defense, offering eco-friendly alternatives to chemical fertilizers and pesticides. Beyond ecological functions, endophytes show potential in biotechnology for sustainable agriculture, conservation, and novel bioactive compound discovery. Despite advances in molecular tools like metagenomics and next-generation sequencing, challenges persist in fully understanding and utilizing these microbes. This review highlights the need for multidisciplinary collaboration to optimize microbial inoculants, elucidate symbiotic mechanisms, and develop practical applications for conservation and sustainable horticulture. By integrating fundamental research with applied strategies, this work aims to unlock the full potential of orchid-associated endophytes in ecological and commercial domains.

Background: Urinary tract infections are among the most frequent healthcare-associated infections and represent a major public health challenge due to their increasing antimicrobial resistance. Data from tertiary-care hospitals in Mexico remain scarce. This study aims to describe prevalence and microbiological profile of healthcare-associated UTIs in a tertiary medical facility in western Mexico.

Methods: A cross-sectional study included all UTI cases recorded from January to December 2024. Data was obtained from the institutional epidemiological surveillance platform (INOSO). Descriptive statistics were applied using measures of central tendency, proportions and confidence intervals. Antimicrobial resistance profiles were analyzed using automated Vitek® testing for Antibiotic susceptibility testing and mass spectrometry for pathogen identification.

Results: A total of 376 patients were included (mean age 52.9 years; 53.2% women). Healthcare-associated UTIs represented 80.6% of cases. Monthly incidence displayed a multimodal pattern with peaks in April and October. Nephrology, Cardiology, and Neurosurgery accounted for >50% of cases. Among 120 isolates, bacteria comprised 70.8%, mainly Escherichia coli (35.8%), Klebsiella pneumoniae, and Pseudomonas aeruginosa; fungal isolates (29.2%) were predominantly Candida albicans. Extensive drug resistance was observed in Providencia rettgeri (resistant to all tested antibiotics) and Acinetobacter baumannii.

Conclusion: UTIs in a tertiary-care hospital in Mexico exhibit high prevalence, multimodal temporal dynamics, and alarming antimicrobial resistance. Continuous surveillance, antimicrobial stewardship, and targeted infection-control strategies are urgently needed in high-risk hospital units.

Background: Biofilm-associated infections pose a formidable challenge due to their high tolerance to conventional antibiotics. While copper-based therapies offer a promising avenue, their clinical utility is severely limited by non-specific cytotoxicity and rapid deactivation. To address this, we engineered an intelligent, redox-responsive nanoplatform composed of Ginsenoside Re (GS) and copper (Cu²⁺), termed GSR NPs.

Methods: GSR NPs were synthesized through a facile self-assembly process using GS and Cu²⁺. The nanoparticles were extensively characterized using microscopy and molecular dynamics simulations. Their physicochemical stability, redox-responsiveness, reactive oxygen species (ROS) generation, and antibacterial efficacy were evaluated against S. aureus and E. coli. Additionally, biofilm disruption capabilities and in vitro biocompatibility were assessed.

Results: Characterization indicated the formation of uniform, ultra-small nanospheres stabilized by coordination and hydrogen bonds. GSR NPs remained stable in physiological buffers but exhibited responsive behavior in reducing microenvironments, triggering the release of active components and ROS generation. Consequently, GSR NPs displayed potent antibacterial activity and effectively disrupted established biofilms of both S. aureus and E. coli, far surpassing the efficacy of individual components. Mechanistic investigations suggest a multi-pronged attack involving physical disruption, oxidative stress induction, and metabolic suppression. Furthermore, the nanoparticles demonstrated favorable biocompatibility with negligible cytotoxicity toward mammalian cells in vitro.

Conclusion: This work presents GSR NPs as a highly efficient and potentially low-toxicity antibacterial strategy. By overcoming the limitations of free copper ions, GSR NPs offer a promising therapeutic alternative for combating challenging biofilm-related infections.

Introduction: The resistance of avian pathogenic Escherichia coli (APEC) poses a serious challenge to the control of bacterial diseases in the poultry industry. Identification of useful phages as alternatives to antibiotics for APEC O₇₈ is a priority.

Methods: The phage LQ5 was isolated from the contents of the chicken intestines. Whole-genome sequencing was performed using the Illumina NovaSeq 2500 platform, and then bioinformatics analysis was conducted on the genome. The application effect of LQ5 in the O₇₈ infection model of chickens was systematically evaluated.

Results: The phage LQ5 was identified as a member of Myoviridae by electron microscopy. Whole-genome sequencing showed that phage LQ5 is a double strand DNA virus with a genome of 171,908 bp containing active components, such as endolysin, holin lysis mediator. Comparison of the bacterial load of APEC in chicken liver and spleen tissue in samples treated with phage LQ5 and Amoxicillin showed that the phage LQ5 reduced the bacterial load compared with the antibiotic.

Discussion: These results have enriched the information of the phage gene bank for APEC, laying the foundation for the development of targeted phage biocontrol agents against the APEC O₇₈ strain.

The STAR-IDAZ international research consortium established a working group on Alternatives to Antimicrobials to explore various approaches for reducing our reliance on antimicrobials. These included bacteriophages, activating the immune system and manipulating the microbiome. The sub-group investigating bacteriophages have developed a road map for the application of phages in a One Health context. We present this roadmap here, in review format, along with a discussion of how phages may be combined with other therapies.

This study investigates the impact of wildfires on the diversity and types of soil microbial functions within Karst forest ecosystems, and examines their relationship with soil nutrients. In particular, we focus on the Quercus fabri broadleaf and Pinus massoniana coniferous forests within areas affected by wildfires in Qiannan, located in the Karst area of Guizhou, Southwestern China. Analysis of soil microbial functional types associated with soil nutrients and their effects was performed using microbial amplicon sequencing technology. Significant differences in the functional diversity of soil bacteria and soil fungi associated with relevant soil nutrients were observed between the Q. fabri broadleaf and P. massoniana coniferous forests in the study area. After fire, the functional diversity of bacteria in both forest types increased significantly, resulting in a convergence in bacterial functional types. Fire enhanced the functional diversity of fungi in the P. massoniana forest; however, had no discernible effect on the Q. fabri forest. In addition, fire altered the types and abundance of microbial functions associated with soil nutrients, exerting a greater impact on bacterial functional types. The results also revealed that fire enhanced the abundance of TOC- and TP-related microbial functional types in both forest types, while reducing TK-related functional types. TN-related functional types increased in the Q. fabri forest but decreased in the P. massoniana forest. At the bacterial level, fire increased TOC-, TN-, and TP-related functional types in both forest types; however, reduced TK-related types. In fungal communities, fire increased TP-related functional groups in the Q. fabri forest while reducing TOC-, TN-, and TK-related groups. In contrast, in the P. massoniana forest, fire increased TOC- and TP-related groups but decreased TN- and TK-related groups. The research findings provide a scientific basis for the restoration and management of the post-fire forest ecosystems in Karst areas.

Introduction: The longevity and operational reliability of offshore mooring chains are critical for the safety of floating oil and gas installations. These chains are subjected to harsh marine environments and numerous stress factors, such as microbiologically influenced corrosion (MIC). This study focuses on MIC on seabed chains under different environments: embedded in sediment or lifted into the water column.

Methods: Microbial communities and corrosion rates on seabed chains were studied during periods of normal operation, with the chains placed with one end in the water column and the other end anchored inside the sediment, and resting periods where the entire seabed chain was on the seabed or buried within. Corrosion rates were measured, and deposits of corrosion products and scale on the seabed chains were studied by microbiological and chemical analysis.

Results: During the study period, microbial communities, including groups of potentially MIC-causing Bacteria and Archaea, were present in the scale material deposited on the surface of the seabed chains. Corrosion rates varied significantly both with time and along the length of the seabed chains, but although the corrosion was at least partly ascribed to MIC, there was no obvious correlation between corrosion rates and numbers of microorganisms present in the local deposits.

Discussion: Several biological and chemical mechanisms are discussed in this paper. The data indicates that complex biogeochemical reactions were contributing to the observed corrosion, including several different biological pathways and types of S- and Fe-cycling, formation of protecting mineral layers and distribution of anodic and cathodic sections locally along the length of the seabed chains. Our findings emphasize the dynamic and unpredictable role of microbial communities, driving complex and spatially structured corrosion.

The Caucasus region, including Georgia, is an important intersection for migratory waterbirds, offering potential for avian influenza virus (AIV) transmission between populations from different geographic areas. In 2022 and 2023, wild ducks were sampled during autumn migration events in Georgia to study the genetic relationships and molecular characteristics of influenza strains. Sequencing and phylogenetic analysis were used to compare the sampled strains to reference sequences from Africa, Asia, and Europe, allowing assessment of genetic relationships and virus transmission between migratory birds. Protein language modeling identified potential co-infections. Of 225 duck samples, 128 tested positive for the influenza M gene. 55 influenza-positive samples underwent whole-genome sequencing, revealing significant diversity. Analysis of the hemagglutinin (HA) segment showed notable differences among subtypes. Most samples were H6N1 and H6N6, but co-infections with combinations like H6H3, N8N1, N6H9, N2N6, and H9H6/N1N2 were also identified. These findings demonstrate the high variability of influenza viruses in migratory waterbirds in Georgia, including a notable rate of co-infections. Some samples exhibited uncommon genetic characteristics compared to other strains from the same year, suggesting Georgia's role as a mixing vessel for influenza viruses. This facilitates reassortment during co-infections and contributes to the genetic diversity observed across flyways.

As a pivotal defense system within the female lower genital tract, the healthy vaginal microecosystem, dominated by Lactobacillus, safeguards against pathogenic microorganisms and maintains overall reproductive health through producing antimicrobial substances and sustaining an acidic environment. However, this intricate ecosystem is susceptible to a variety of adverse factors that trigger vaginal microbiota (VMB) dysbiosis, which further precipitate vaginal infections and gynecological disorders. Based on rigorous clinical evidence, this review systematically summarizes current mechanistic understanding of Lactobacillus-mediated VMB homeostasis. It evaluates the therapeutic potential of probiotics in both pharmaceutical and dietary supplement forms, and discusses the clinical necessity and existing challenges in developing live biotherapeutic products (LBPs) targeting the vaginal microecology. By integrating perspectives from both basic research and translational medicine, this work provides a theoretical foundation for developing targeted microbiota modulation strategies, thereby advancing precision medicine approaches for the management of vaginal dysbiosis.