Search Results (839)

To address the challenges of low land use efficiency, soil degradation, and high management costs in Ilex asprella cultivation, this study established an I. asprella–Grona styracifolia intercropping system and systematically evaluated its effects on soil nutrient cycling, microbial communities, and crop growth. Field experiments were conducted in Yunfu City, Guangdong Province, with monoculture (LCK for I. asprella, DCK for G. styracifolia) and three intercropping densities (HDT, LDT, MDT). Combining 16S rRNA sequencing and metagenomics, we analyzed the functional profile of the rhizosphere microbiome. The results showed that intercropping significantly increased the biomass of G. styracifolia, with the medium-density (MDT) treatment increasing plant length and fresh weight by 41.2% and 2.4 times, respectively, compared to monoculture. However, high-density intercropping suppressed the accumulation of medicinal compounds. In terms of soil properties, intercropping significantly enhanced soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and available nitrogen (AN) in the rhizosphere of both plants. Specifically, AN in the I. asprella rhizosphere increased by 18.9%. Soil urease and acid phosphatase activities were also elevated, while pH decreased. Microbial analysis revealed that intercropping reshaped the rhizosphere microbial community structure, significantly increased the Shannon diversity index of bacteria in the G. styracifolia rhizosphere, and enhanced the complexity of the microbial co-occurrence network. Metagenomic analysis further confirmed that intercropping enriched functional genes related to carbon fixation, nitrogen cycling (nitrogen fixation, assimilatory nitrate reduction), and organic phosphorus mineralization (the phoD gene), thereby driving the transformation and availability of soil nutrients. These findings demonstrate that the I. asprella–G. styracifolia intercropping system, particularly at medium density, effectively improves soil fertility and land use efficiency by regulating rhizosphere microbial functions, providing a theoretical basis for the sustainable ecological cultivation of I. asprella. Full article

Antimicrobial resistant (AMR) infections are a persistent public health issue causing excess death and economic impacts globally. Because AMR in clinical settings is often acquired from nonpathogenic bacteria that surround us, environmental surveillance must be better characterized. It has been well established that metals can co-select for bacterial AMR. Furthermore, recent studies have shown that compromised microbial community diversity may lead to community invasion by antibiotic resistance genes (ARGs). Widespread legacy mining has led to acid mine drainage and metal contamination of waterways and sediments throughout the western United States, potentially compromising microbial community diversity while simultaneously selecting for AMR bacteria. Our study objectives were to survey metal contaminated sediments from the Bonita Peak Mining District (BPMD) in southwestern Colorado, USA, compared to sites downstream in Durango, CO for bacterial and ARG diversity. Sediment bacteria were characterized using 16S rRNA Ilumina and metagenomic sequencing. We found that overall, bacterial diversity was lower in metal-contaminated, acidic sites (p = 0.04). Metagenomic sequencing revealed 31 different ARGs, with those encoding for efflux pumps (mex and spe gene families) substantially more prevalent in the BPMD sites, elucidating a specific AMR marker fingerprint from the high metal concentration sediments. Raising awareness and providing antimicrobial tracking techniques to resource limited communities could help provide information needed for better antibiotic use recommendations and environmental monitoring. Full article

Background: Stenotrophomonas maltophilia is an increasingly important multidrug-resistant opportunistic pathogen frequently isolated from clinical, environmental, and plant-associated niches. Despite its medical relevance, the global population structure, species-complex boundaries, and genomic determinants of antimicrobial resistance (AMR) and ecological adaptation remain poorly resolved, partly due to inconsistent annotations and fragmented genomic datasets. Methods: Approximately 2400 genome assemblies annotated as Stenotrophomonas maltophilia were available in the NCBI Assembly database at the time of query. After pre-download filtering to exclude metagenome-assembled genomes and atypical lineages, 1750 isolate genomes were retrieved and subjected to stringent quality control (completeness ≥90%, contamination ≤5%, ≤500 contigs, N50 ≥ 10 kb, and ≤1% ambiguous bases), yielding a final curated dataset of 1518 high-quality genomes used for downstream analyses. Genomes were assessed using CheckM, annotated with Prokka, and compared using average nucleotide identity (ANI), pan-genome analysis, core-genome phylogenomics, and functional annotation. AMR genes, mobile genetic elements (MGEs), and metadata (source, host, and geographic origin) were integrated to assess lineage-specific genomic features and ecological distributions. Results: ANI-based clustering resolved the S. maltophilia complex into multiple distinct genomospecies and revealed extensive misidentification of publicly deposited genomes. The pan-genome was highly open, reflecting strong genomic plasticity driven by accessory gene acquisition. Core-genome phylogeny resolved well-supported clades associated with clinical, environmental, and plant-related niches. Resistome profiling showed widespread intrinsic MDR determinants, with certain lineages enriched for efflux pumps, β-lactamases, and trimethoprim–sulfamethoxazole resistance markers. MGE analysis identified lineage-specific integrative conjugative elements, prophages, and transposases that correlated with source and geographic distribution. Conclusions: This large-scale analysis provides the most comprehensive genomic overview of the S. maltophilia complex to date. Our findings clarify species boundaries, highlight substantial taxonomic misannotation in public databases, and reveal lineage-specific AMR and mobilome patterns linked to ecological and clinical origins. The curated dataset and evolutionary insights generated here establish a foundation for global genomic surveillance, epidemiological tracking, and future studies on the evolution of antimicrobial resistance in S. maltophilia. Full article

Overwinter Syndrome (OWS) affects grass carp (Ctenopharyngodon idellus) aquaculture in China, causing high mortality and economic losses under low temperatures. Failure of antibiotic therapies shows limits of the ‘low–temperature–pathogen’ model and shifts focus to mucosal barrier dysfunction and host–microbiome interactions in OWS. We compared healthy and diseased grass carp collected from the same pond using histopathology, transcriptomics, proteomics, and metagenomics. This integrated approach was used to characterize intestinal structure, microbial composition, and host molecular responses at both taxonomic and functional levels. Results revealed a three-layer barrier failure in OWS fish: the physical barrier was compromised, with structural damage and reduced mucosal index; microbial dysbiosis featured increased richness without changes in diversity or evenness, and expansion of the virobiota, notably uncultured Caudovirales phage; and mucosal immune dysregulation indicated loss of local immune balance. Multi-omics integration identified downregulation of lysosome-related and glycosphingolipid biosynthesis pathways at transcript and protein levels, with disrupted nucleotide metabolism. Overall gut microbial richness, rather than individual taxa abundance, correlated most strongly with host gene changes linked to immunity, metabolism, and epithelial integrity. Although biological replicates were limited by natural outbreak sampling, matched high-depth multi-omics datasets provide exploratory insights into OWS-associated intestinal dysfunction. In summary, OWS entails a cold-triggered breakdown of intestinal barrier integrity and immune homeostasis. This breakdown is driven by a global restructuring of the gut microbiome, which is marked by increased richness, viral expansion, and functional shifts, ultimately resulting in altered host–microbe crosstalk. This ecological perspective informs future mechanistic and applied studies for disease prevention. Full article

Recent studies have revealed a specific relationship between gut bacteria and inflammatory skin profiles. We aimed to perform a species-level comparative metagenomic analysis of the gut microbiome in patients with psoriasis, hidradenitis suppurativa (HS), and pemphigus foliaceus (PF). We included omnivorous nonsmokers and nondrinkers with psoriasis (n = 24), HS (n = 10), and PF (n = 11), as well as healthy controls (n = 10). We collected faecal samples from all patients for classic parasitological analysis. Gut microbiome analysis was conducted using shotgun next-generation sequencing. We used the Deseq2, Limma_voom, LinDA, and MaAMaAsLin 2 bioinformatics tools to evaluate concordance and differential abundance between patients. Thirteen patients (23.64%) were diagnosed with active intestinal parasitosis. The presence of intestinal parasitosis was significantly related to immunosuppression (p = 0.009). The most abundant microorganism species found in the faeces of the patients evaluated was Escherichia coli. Psoriasis patients presented a greater abundance of bacteria from the Veillonellaceae family, whereas PF patients presented a greater abundance of Firmicutes bacteria. Patients with PF showed increased E. coli virulence and antibiotic resistance functional markers. Immunosuppression significantly influenced the presence of intestinal parasitosis as well as increased the virulence of functional markers in patients with PF receiving systemic corticosteroid therapy. Full article

Gut microbes play a crucial role in regulating physiological processes such as host energy metabolism, nutrient absorption, and environmental adaptation. The predicted functions of gut microbes can be influenced by many factors, both extrinsic and intrinsic to the hosts. The plateau pika is a key species in the alpine ecosystem of the Qinghai–Tibet Plateau. Previous research on the plateau pika primarily examined how extrinsic factors affected its gut microbiota. However, studies on intrinsic factors are scarce. Here, we used live-trapping to capture plateau pikas and collect cecum contents. Using metagenomic sequencing of cecum content samples, we characterized and compared the gut microbial composition and predicted function of plateau pika in adult (n = 9) and juvenile (n = 9) populations. The results indicated that Bacillota and Bacteroidete were the major bacterial phyla. The core gut microbial genera were the same, but the relative abundance of Oscillospira in juveniles was significantly lower than that in adults. The changes in the proportion of cellulose-degradation-related bacterial communities in juveniles suggest that they tend to choose low-fiber diets. In this study, we found no significant differences in the gut microbial composition and diversity, KEGG level 1 metabolic pathways, or CAZy class level between adult and juvenile plateau pikas. In total, the composition and predicted functions of cecal microorganisms in juvenile and adult male plateau pikas were not different. Regarding KEGG level 2 metabolic pathways, the juvenile group had a higher relative abundance of metabolic pathways for cofactors and vitamins, terpenoids, and polyketides, whereas the adult group had a higher relative abundance of energy metabolism. However, the resulting differences remain unclear. Therefore, future research should validate the above findings on a broader spatio-temporal scale and conduct cross-species comparisons to construct a microbial ecological framework for the health management of plateau wild animals. Full article

The rising global burden of colorectal cancer (CRC) has now positioned it as the third most common cancer worldwide. Chemotherapy regimens are known to disrupt the composition of the gut microbiota and lead to long-term health consequences for cancer patients. However, the alteration of gut microbiota by specific chemotherapeutic agents has been insufficiently explored until now. The purpose of this study was to assess changes in the gut microbiota following treatment with VERU-111 as a chemotherapy agent for the treatment of CRC. We thus performed a metagenomic study using 16S rRNA gene amplicon sequencing of fecal samples from different experimental groups in the azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced murine model of CRC. To predict the functional potential of microbial communities, we used the resulting 16S rRNA gene sequencing data to perform Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. We found that the administration of VERU-111 led to a restructured microbial community that was characterized by increased alpha and beta diversity. Compared to the mice treated with DSS alone, VERU-111 treatment significantly increased the relative abundance of several bacterial species, including Verrucomicrobiota species, Muribaculum intestinale, Alistipes finegoldii, Turicibacter, and the well-known gut-protective bacterial species Akkermansia muciniphila. The relative abundance of Ruminococcus, which is negatively correlated with immune checkpoint blockade therapy, was diminished following VERU-111 administration. Overall, this metagenomic study suggests that the microbial shift after administration of VERU-111 is associated with suppression of several metabolic and cancer-related pathways that might, at least in part, facilitate the suppression of CRC. These favorable shifts in gut microbiota suggest a novel therapeutic dimension of using VERU-111 to treat CRC and emphasize the need for further mechanistic exploration. Full article

In view of the technical bottleneck of microbial dynamic monitoring during the solid-state fermentation of traditional Baijiu, this study introduced green fluorescent protein (GFP) labeling technology into the dominant Saccharomyces cerevisiae of Jiang-flavored Baijiu to construct the chromosomal integration engineering strain named FSC01. By designing an integrated recombinant plasmid containing the GFP gene and the geneticmycin resistance gene, an engineered strain that stably expresses fluorescent proteins was obtained by electroconversion. Flow cytometry verification showed that FSC01 showed excellent linear responses in the pure microbial system (R² = 0.998) and the complex matrix of Baijiu jiupei (R² = 0.981), with a detection limit of 10² cells/mL, and the detection cycle was shortened to 10 min. Solid-state fermentation simulation experiments show that the inoculation volume of FSC01 of 10⁵ cells/kg can not only ensure the effective identification of fluorescence signals, but also does not significantly interfere with the growth and growth patterns of the original yeast (p > 0.05), which is highly consistent with the results of the traditional plate counting method. Dynamic monitoring shows that Saccharomyces cerevisiae during fermentation presents a typical succession pattern of “increase first and then decrease”, reaching a peak on the 7th day (1.2 × 10⁷ cells/g), which is positively correlated with the base alcohol yield rate (26.7%). Compared with metagenomic (72 h) and PMA-qPCR (4 h) methods, this technology breaks through the limitations of specificity and timeliness of live bacteria detection, and provides a single-cell-level dynamic analysis tool for the digitization of traditional brewing processes. In the future, it will be expanded to monitor key functional microorganisms such as lactic acid bacteria through a multi-color fluorescent labeling system, and optimized pretreatment to eliminate starch granule interference, and promote the in-depth application of synthetic biology technology in the traditional fermentation industry. Full article

The annual nitrogen loss from the livestock production sector poses a significant threat to the global natural environment. Therefore, it is urgent to focus on improving the nutrient utilization efficiency of ruminants and promoting the sustainable development of livestock production. Twelve 60-day-old Ganxi goats with similar body weights were selected and randomly assigned to two dietary treatment groups. The control group was fed only a basal diet, while the treatment group was supplemented with 32 mg/d of Swollenin. The experiment lasted for 30 days. At the end of the experimental period, the goats were euthanized, and their intestinal contents were collected, rapidly frozen, and stored at −80 °C for subsequent metagenomic and metabolomic analyses. In the Swollenin group, we observed changes in gut microbiota structure and significantly enhanced feed conversion efficiency compared to the control group. Notably, genera such as Bacteroides, Ruminococcus, and Bifidobacterium exhibited significantly higher abundance. Following Swollenin supplementation, the gene abundance associated with the secondary bile acid biosynthesis pathway in the intestinal tract of young goats was significantly higher. The levels of primary bile acids (BAs), including taurocholic acid, glycocholic acid, taurochenodeoxycholic acid, and glycochenodeoxycholic acid, were significantly lower, while the concentrations of secondary BAs such as ursodeoxycholic acid and deoxycholic acid were significantly higher. The abundance of nitrogen-fixing and nitrogen-assimilating genes in the gut of young goats in the Swollenin group was significantly higher. Furthermore, co-occurrence network analysis revealed a strong correlation between bile acid metabolism and nitrogen metabolism pathways. These results suggest that nutritional regulation may serve as a preventive strategy to optimize the symbiotic development of animals and their gut microbiota, ultimately improving nitrogen utilization. Full article

Long-term continuous cropping is a prevalent agricultural practice aimed at maximizing land use efficiency and crop yields, yet it often leads to severe soil degradation, nutrient imbalance, and microbial community disruption. Effective soil remediation strategies are urgently needed to restore soil health and ensure sustainable agricultural production. In this study, we investigated the impact of forest soil amendment on microbial community structure, diversity, and functional potential in long-term continuous cropping soils. Using metagenomic sequencing, we analyzed soils from natural forest (BK), forest soil-amended soils (BCP), and fields under continuous cropping for 15 years (CP15) and 30 years (CP30). Forest soil amendment significantly mitigated microbial diversity loss and structural degradation caused by prolonged monoculture. Alpha diversity analysis revealed that BCP restored microbial diversity to levels comparable to BK, while beta diversity and NMDS analyses showed that microbial community composition in BCP closely resembled that of forest soil. Taxonomic profiling indicated that forest soil amendment enriched beneficial taxa such as Actinobacterota and Acidobacteriota, reversing shifts observed in CP15 and CP30. Functionally, COG and KEGG annotations revealed that BCP soils exhibited higher abundances of genes involved in carbohydrate metabolism, energy production, and nutrient cycling. Notably, the amendment reduced antibiotic resistance genes and virulence factors, potentially improving the microbial risk profile of soil communities. These findings demonstrate that forest soil amendment effectively restores microbial community structure and functionality in degraded soils, providing a nature-based solution for sustainable agriculture. Full article

The Sumaco volcano in Ecuador, which has a distinct geological origin from the Andes and is located in the Amazon basin, offers an opportunity to study untouched microbiomes. We explored comparative patterns of abundance from predicted functional profiling in soil samples collected along the elevation and sulfur gradients on its slopes. Using 16S rRNA gene metabarcoding, we inferred metagenome functional profiles, contrasting sample groups by altitude or soil sulfur concentration. We inferred that high-altitude communities may have higher predicted abundance for anaerobic metabolism (crotonate fermentation), coenzyme B12 synthesis, and degradation of diverse carbon sources (sugars and octane). High-sulfur soils were associated with an inferred enrichment of pathways for degrading complex organic compounds and nitrogen metabolism, reflecting adaptation to unique geochemical conditions. In contrast, low-sulfur soils are consistent with a higher predicted abundance of glycerol degradation. Within the limitation imposed by the potential weak associations of the applied predicted functional profiling to actual gene content, we propose that the inferred metabolic changes represent different ecological strategies for resource acquisition, energy generation, and stress tolerance, and they are optimized for varying conditions in this unique volcanic ecosystem. Our findings highlight how environmental gradients shape soil microbiome functional diversity and offer insights into microbial adaptation in Sumaco’s exceptional geochemistry within the Amazon. Further efforts linking functional predictions back to specific taxa will offer a complete ecological perspective of the microbiome exploration in the Sumaco volcano. Full article

Background/Objectives: Plasmids are autonomous DNA molecules that can replicate independently and transfer horizontally between bacterial cells. They play a key role in disseminating adaptive traits, such as antimicrobial resistance and virulence. Our study investigates the fundamental differences between plasmid populations originating from clinical/isolates and environmental/metagenomes. Methods: We compare three distinct plasmid genome datasets—the NCBI Reference Sequence Database (RefSeq), the Integrated Microbial Genomes & Microbiomes system (IMG/PR) from bacterial isolates (I) and microbiomes (M)—to assess how plasmid origin shapes their characteristics, including mobility types, antimicrobial resistance genes (ARGs), virulence genes (VGs) and host taxonomy. Results: We show that plasmids originating from bacterial isolates, more enriched in clinical samples, are fundamentally distinct from recovered from metagenomic data. Plasmids from isolates are larger, enriched in conjugative plasmids and display a higher frequency of ARGs and VGs than the ones assembled from metagenomes. Furthermore, ARGs are more frequently associated with highly mobile plasmids, particularly pCONJ. Conclusions: These findings highlight the importance of plasmid origins in studies of plasmid epidemiology, functional potential and mobility. Full article

The oral microbiome has become an emerging focus of oral cancer research, with growing evidence linking microbial communities to disease development, progression, and prognosis. However, there is limited consensus on optimal sampling strategies, storage methods, and analytical approaches. This narrative review critically evaluates current strategies for sampling, preservation, DNA extraction, sequencing, and data analysis in oral microbiome research related to oral cancer. We compared commonly used sampling methods, including saliva, oral rinse, swab, brush, and tissue biopsy, and reviewed preservation conditions, extraction kits, sequencing platforms, and analytical pipelines reported in recent oral microbiome studies. Sampling approaches affect microbial yield and site specificity. Saliva and oral rinse samples are convenient and noninvasive but may dilute lesion-specific microbial signals, whereas lesion-directed swabbing or brushing yields greater microbial biomass and biological relevance. Preservation media and storage temperature significantly influence microbial stability, and DNA extraction methods vary in their ability to remove host DNA. Although 16S rRNA gene sequencing remains the most common approach, shotgun metagenomics offers higher resolution and function insights but is still limited by clinical applicability. Differences in data pre- and post-processing models and normalization strategies further contribute to inconsistent microbial profiles. Given that oral mucosal sites differ markedly in structure and microenvironment, careful consideration is required to ensure that collected samples accurately represent the biological question being addressed. Methodological consistency across all workflow stages—from collection to analysis—is essential to generate reproducible, high-quality data and to enable reliable translation of oral microbiome research into clinical applications for cancer detection and risk assessment. Together, these insights provide a framework to guide future study design and support the development of clinically applicable microbiome-based biomarkers. Full article

Fertilization regimes impact the carbon cycle processes in paddy soils. However, the effects of shifting fertilization regimes on the structure of microbial communities and functional genes involved in soil carbon (C)-cycling remain unclear. A long-term field experiment was established with three paired fertilization shift treatments: chemical fertilizer (CF) and CF to normal-rate organic fertilizer (CF-NOM); normal-rate organic fertilizer (NOM) and NOM to CF (NOM-CF); high-rate organic fertilizer (HOM) and HOM to CF (HOM-CF). Metagenomic sequencing and bioinformatics analysis were employed to investigate the effects of fertilization shifts on soil C-cycling microbial community structure, functional genes, and environmental factors. The results showed that compared to CF treatment, CF-NOM significantly increased soil organic carbon (SOC), mineral-associated organic carbon (MAOC), particulate organic carbon (POC), microbial biomass carbon (MBC), dissolved organic carbon (DOC), and the emissions of CO₂ and CH₄ (p < 0.05). The NOM-CF led to significant reductions in MAOC, MBC, DOC, and CO₂ and CH₄ emissions. The HOM-CF shift caused significant decreases in SOC, MAOC, POC, MBC, DOC, and CO₂ and CH₄ emissions. Fertilization shifts had no significant effect on the α-diversity of C-cycling microbial communities (p > 0.05), but β-diversity showed a significant restructuring of community composition. Network analysis indicated that fertilization shifts increased positive microbial correlations while reducing network modularity. C-cycling functional genes responded sensitively to fertilization disturbances, especially key genes in the carbon fixation pathway (cdhDE, cooS). Redundancy analysis indicated that soil bulk density (BD) and POC are key environmental factors regulating functional differences in carbon metabolism, which collectively influenced microbial community structure and functional gene abundance along with other factors. We concluded that the C-cycling process in paddy soil was greatly altered by shifts in fertilization regimes, influenced by microbial diversity, functional genes, and network structure linked to soil characteristics. Full article

The aim of this study was to compare, using culture methods, the microflora of the small and large intestines, distinguishing pathogenic bacteria, in free-living ruminants: roe deer (Capreolus capreolus) and red deer (Cervus elaphus). Intestinal samples from six individuals of each species were collected immediately after hunting under aseptic conditions. Aerobic and facultatively anaerobic bacteria, including Lactobacillus spp., Escherichia coli, Listeria spp., and Clostridium perfringens, were quantified using standard culture methods. Statistical analysis (ANOVA) revealed no significant differences (p > 0.05) between species in any of the microbial groups analyzed, although higher mean abundances were observed in red deer, particularly in the large intestine. The results indicate that interspecific variation in cultured microbiota may reflect individual and environmental factors rather than consistent taxonomic differences. Due to the high inter-individual variability and limited sample size, this study should be considered preliminary. The results demonstrate the predominance of viable aerobic and facultative anaerobic bacterial groups in culture-based analysis and provide reference data for future metagenomic studies. This study fills an important knowledge gap, as culture-dependent studies of the gut microbiota of wild cervids are still rare due to the logistical and ethical constraints associated with sampling wild animals. Full article