MicrobiologyOpen最新文献

Detection of Salmonella Enteritidis (SE) and S. Typhimurium (STm) in broiler holdings is regulated by European and Swiss law to ensure public health. Persistence of Salmonella in broiler houses may jeopardize this goal. The aim of this study was to analyze whether non-SE/STm isolated from boot socks were of clonal origin. Four Salmonella serovars from 11 broiler houses from 10 Swiss farms were selected: S. Infantis, S. Livingston and S. Welikade (meat integration A) and S. enterica subsp. enterica 13,23:i:- (integration B). The genetic relationship was evaluated by whole-genome sequencing (WGS) and core genome multilocus sequence typing (cgMLST)-based tree analysis, with a cluster being defined as < 8 cg alleles differences. The isolates of S. Infantis and S. Livingston, respectively, were shown to belong to the same serovar-specific clusters (range: 1–7 cg alleles differences), suggesting that the Salmonella strains persisted in the respective broiler houses. S. Welikade, however, showed 8–11 cg alleles differences among isolates, indicating either a reintroduction of similar but not clonal strains into the houses due to insufficient biosecurity, or the evolution of a persistent strain. Remarkably, all isolates of S. 13,23:i:- from integration B from 2013 to 2024 were clonal, suggesting dispersal and persistence in the broiler integration. The clonality of analyzed strains suggests that Salmonella can persist on farms or integration level despite disinfection after each production cycle. Hence, improved farm and vehicle cleaning and disinfection practices are essential to ensure that the next flock is not exposed to non-SE/STm Salmonella serovars.

Microbial biotechnology plays a critical role in addressing environmental challenges and promoting sustainability. Here, we report the complete genome sequencing of Paenibacillus sp. strain 210, previously isolated from Brazilian crude oil and known for its levan metabolism and biosurfactant production. With the sequenced genome, we employed bioinformatics tools for assembly and annotation, followed by comprehensive in silico analyses, including phylogenomics, biosynthetic gene cluster (BGC) identification, carbohydrate-active enzyme (CAZyme) profiling, and metabolic pathway reconstruction. The assembled 5.7 Mb genome harbors four prophage regions and 13 antimicrobial BGCs, including those encoding fusaricidin, paenicidin A, paenilan, paeninodin, and tridecaptin. Phylogenomic analysis combined with average nucleotide identity measurements indicates that this strain does not cluster with any recognized Paenibacillus species, supporting its designation as a potential new species. Notably, the identification of 259 CAZyme genes points to a strong capacity for degrading complex polysaccharides (e.g., cellulose, xylan, and pectin), positioning this bacterium as a promising candidate for biofuel production. Furthermore, the presence of complete metabolic pathways for several B vitamins highlights predicted metabolic autonomy supporting microbial interactions, reinforcing their usefulness in soil bioremediation by enhancing nutrient availability. In contrast, incomplete pathways for vitamins B2 and K2 indicate metabolic dependencies that may facilitate syntrophic interactions with other microorganisms. In silico structural analyses of selected hydrolytic enzymes (GH1, GH5, and GH11) reveal homology to functionally validated and crystallized proteins. Collectively, these findings highlight the genetic versatility of Paenibacillus sp. strain 210 and its potential for ecosystem restoration, biofuel production, plant growth promotion, and biocontrol.

Vaginal microbiota is essential for mucosal immunity, pathogen defense, and homeostasis. Disruption of this balance can promote opportunistic infections, notably by Candida albicans. This study investigates the therapeutic potential of Morus alba (MA) extract and Lactobacillus rhamnosus (LR) in a rat model exposed to Candida albicans exosomes (CAE). CAE induced a 1.3–5.1-fold upregulation in SAP1–10 gene expression, with SAP4 showing the highest increase (p ≤ 0.05). MA and LR monotherapies selectively suppressed SAP6 (41%) and SAP4 (23%), respectively. Notably, combination therapy (CAE+MA+LR) synergistically inhibited all SAP genes (0.8–1.1-fold, p ≤ 0.05). 16S rRNA analysis showed that LR-containing groups maintained Lactobacillales abundance (37.77%–38.7%), while MA reduced Mycobacteriales by 68.5% (p = 0.004). Microbial diversity was lower in the MA group (H = 3.242) but higher in LR groups (H = 5.493–5.598). Histopathology revealed severe ovarian inflammation in the CAE group (87.4%, p = 0.0022) with a 4.2-fold increase in IL-6, while combination therapy reduced inflammation and IL-6 levels by 60%–72% (p ≤ 0.05). Immunofluorescence confirmed downregulation of TLR4 and Caspase-3 with treatment. FIB-SEM and NTA analyses showed that CAE exosomes had a heterogeneous morphology (99.3 ± 31.1 nm) and high polydispersity (PDI = 0.31). These results suggest that MA and LR synergistically reduce fungal virulence, restore microbial balance, and offer a promising adjuvant strategy against vaginal candidiasis.

Marine virioplankton, the most abundant biological entities in the ocean, play essential roles in microbial ecology and biogeochemical cycling. This study investigates their biogeography in the Northwest Pacific using enhanced-resolution flow cytometry and phenotypic diversity analyses. By resolving four consistent viral subclusters across oceanic and coastal waters and detecting a fifth subcluster in the Yellow Sea, we revealed previously unrecognized patterns of viral community structures. Viral abundances ranged from 3.69 × 10⁶ to 17.09 × 10⁶ particles/mL, showing clear coastal-oceanic differentiation. Environmental gradients, particularly temperature, chlorophyll, and picoplankton abundance, emerged as the primary drivers of virioplankton community structure. These findings underscored the tight coupling between viral populations and their microbial hosts across contrasting marine environments. Phenotypic diversity analysis revealed distinct viral communities in the Luzon Strait, despite comparable abundance patterns to adjacent regions, demonstrating the method's sensitivity in detecting subtle community shifts. This study advances understanding of marine viral biogeography and introduces a robust framework for investigating viral community dynamics. The approach enables high-throughput screening across large spatial scales while maintaining sensitivity to fine-scale community variations, offering new possibilities for monitoring viral responses to environmental change in marine ecosystems.

Spores of a hot spring isolated strain of Bacillus subtilis were tested as a biotechnological tool to be used for the detoxification and bioremedition of heavy metals. Lead and cadmium were efficiently adsorbed by B. subtilis spores with those of C1 more efficient than those of the lab collection strain PY79. Metal-adsorption did not alter the functionality of C1 spores that were still fully resistant to heat, ethanol or chloroform and able to germinate after the interaction with Cd²⁺ or Pb²⁺. The spore-adsorbed metals were released upon disruption of the spore coat layers, suggesting that the metals were mostly accumulated within the spore coat. Heat-inactivated spores released almost all adsorbed metals, allowing the recovery of Cd²⁺ and Pb²⁺. While Cd²⁺ polluted water impaired the normal germination and growth of seeds of the model plant Arabidopsis thaliana, treatment of the polluted water with C1 spores restored plant growth.

Gut microbes are closely related to host immunity and health, and mice are frequently used as a common model organism in biomedicine to study various diseases. Numerous studies based on mouse gut microbes have been conducted, but whether there are differences in the gut microbial profiles of healthy mice of different strains has not been revealed. In this study, we performed a meta-analysis comparing four strains (inbred strains: C57BL and BALB; outbred strains: KM and ICR) of mouse healthy gut microbial 16S V3-V4 data based on publicly available online data. We focused on microbial diversity, microbial composition, abundance differential microbiota, and co-abundance networks. We found that the gut microbes of these four strains of mice differed in the above metrics to varying degrees. Our study found significant differences in gut microbiology among four strains of healthy mice. The strain will be a background factor that cannot be ignored in future studies of gut microbiology in mice. The impact of this factor on gut microbiology experiments should be considered.

Respiratory aspergillosis refers to a range of infections, from allergic to chronic and invasive, which can be life-threatening and are primarily caused by Aspergillus fumigatus and Aspergillus flavus. Other species, including Aspergillus terreus, Aspergillus nidulans, and Aspergillus versicolor, have also been implicated in respiratory infections. Treatment for chronic to invasive pulmonary aspergillosis typically involves azole antifungal drugs, although studies have shown varying minimum inhibitory concentrations (MIC) for these medications, with a growing concern over voriconazole resistance. During the period from August 2022 to May 2024, characteristic hyphae were detected in 7.2% of lower respiratory samples, with culture positivity in 12.8%, including early morning sputum and bronchoalveolar lavage fluid samples. A. flavus (n = 282) was the most frequently isolated species, followed by A. fumigatus (n = 86). Additionally, a seasonal trend was observed for Aspergillus infections, with peaks in April and September. The MIC of itraconazole, voriconazole, posaconazole, amphotericin B, ravuconazole, and caspofungin were assessed for the isolated Aspergillus species. A higher MIC of amphotericin B was observed against A. flavus and A. terreus, whereas azoles exhibited a relatively lower MIC. Caspofungin and posaconazole exhibited the lowest MIC against the isolated Aspergillus species. Therefore, it is crucial to identify the causative fungi and determine the antifungal MIC for Aspergillus species responsible for lower respiratory tract infections. This study emphasizes the significance of respiratory aspergillosis in TB-endemic regions of Eastern India.

Malaria is a life-threatening disease caused by Plasmodium, transmitted through the bites of infected female Anopheles mosquitoes. Despite global efforts, malaria remains a major health burden in developing countries. In Tanzania, cultural beliefs and misconceptions often delay treatment, especially in rural areas. This article aims to evaluate the level of malaria knowledge among the Tanzanian population and identify demographic factors associated with disparities in awareness. This cross-sectional study used secondary data from the 2021–2022 Tanzania Demographic and Health Survey, analyzing responses from 18,747 individuals aged 15 years and older. Data on malaria-related knowledge, attitudes, and practices were collected through standardized questionnaires. Malaria knowledge varied significantly by age, gender, education, and location (p < 0.05). Awareness was highest among individuals aged 20–24 and lowest among those over 50. Urban residents had greater knowledge than their rural counterparts. Education was strongly linked to awareness, with those having secondary or higher education scoring better. Male-headed households showed slightly higher knowledge levels. Media exposure and mobile phone ownership were also associated with increased malaria awareness. Bridging knowledge gaps through targeted education, digital tools, and improved rural health infrastructure is essential for effective malaria control in Tanzania.

Karst freshwater systems represent unique ecological niches where physicochemical and biological interactions promote intensive calcium carbonate precipitation and the formation of tufa barriers. Here, we studied the composition, diversity, and functional potential of prokaryotic and microeukaryotic communities involved in early-stage tufa formation at two sites within the Plitvice Lakes National Park, Croatia. Over a 5-day period in two different seasons, tufa and water samples were collected at Prošćansko Lake and Novakovića Brod to examine temporal and spatial microbial dynamics. High-throughput sequencing revealed early stabilization of prokaryotic communities within tufa biofilms, dominated by genera, such as Bacillus, Delftia, Hyphomicrobium, and Methylobacterium–Methylorubrum, which are linked to carbonate precipitation processes. With biofilm maturation, shifts toward Acinetobacter and Rhodoferax indicated increasing heterotrophic activity and organic matter degradation. In contrast, microeukaryotic communities were more variable, with diatoms and Zygnemophyceae contributing to extracellular polymeric substance production, crucial for carbonate entrapment. Site-specific patterns reflected environmental influences, such as hydrodynamics and terrestrial organic input. The results underscore the importance of microbial succession and community specialization in the formation and stability of tufa barriers, offering new insights into microbial contributions to biogeochemical processes in karst freshwater systems.