Search Results (103)

The increasing consumption of fresh organic produce has given rise to concerns regarding the microbiological safety of minimally processed foods. Organic cultivation may be associated with increased exposure to environmental microorganisms due to soil-based inputs and reduced chemical interventions, including both beneficial taxa and potential foodborne pathogens. Fresh produce is known to harbour complex microbial ecosystems, which are shaped by farming practices, plant physiology, handling, packaging and storage, particularly in raw-consumed products such as leafy greens and strawberries. In this study, bacterial (16S rRNA) and eukaryotic (18S rRNA) communities were characterized by amplicon sequencing. In parallel, an amoeba-associated bacterial microbiome was analyzed and DVC-FISH was used to assess the viability and metabolic activity of pathogenic bacteria internalized within free-living amoebae (FLA). No significant differences in alpha or beta diversity were observed between organic and conventional products, suggesting microbiome convergence at the retail stage driven by post-harvest handling and processing. Potentially pathogenic genera, including Pseudomonas, Stenotrophomonas, and Acinetobacter (bacterial), as well as Tilletiopsis, Candida, and Naegleria (eukaryotic), were identified in both organic and non-organic microbiomes. The viability of FLA-internalized Pseudomonas spp. was confirmed by DVC-FISH, demonstrating that FLA act as reservoirs, enhancing pathogen persistence in fresh produce. This integrated assessment of organic and conventional fruits and vegetables at the retail stage highlights the importance of post-harvest handling and retail conditions in shaping microbiological safety. The integration of microbiome profiling with targeted viability analyses demonstrates that downstream stages are critical control points for food safety and consumer exposure, beyond the influence of the production system alone. Full article

This study characterizes AP-20-A, a lytic podovirus infecting Sinorhizobium meliloti, isolated from agricultural chernozem. Its 49.4 kbp genome shows negligible intergenomic similarity with known rhizobiophages (<2%). Core structural proteins—the major capsid protein (MCP) and terminase large subunit (TerL)—show closest homology to podoviruses infecting Paenibacillus, rather than to alphaproteobacterial viruses, suggesting cross-phylum horizontal gene transfer. This exchange is ecologically plausible, as Paenibacillus and Sinorhizobium co-exist in the rhizosphere. Over 63% of predicted proteins are functionally uncharacterized, with structural homologs detected in bacteria, archaea, and eukaryotes. We report the first identification in a rhizobiophage of a Tad2-like domain, predicted to block the bacterial Thoeris type II anti-phage defense. AP-20-A infected 56% of native S. meliloti strains; agrocenose isolates showed higher resistance than phytocenose isolates, evidence of local co-evolution. Among susceptible strains, 60% entered putative pseudolysogeny (with one strain exhibiting growth stimulation), whereas a symbiotically elite inoculant strain was completely lysed within hours. Some host strains carry additional AbiE systems; whether these independent defense–counterdefense layers interact during infection remains unknown. We conclude that resident phages represent a selective force that can disrupt inoculant establishment, underscoring the need to integrate soil virome assessment into agricultural microbiome management. Full article

The rectal mucosa houses a large number of viruses with important roles in shaping the local microbial communities and modulating immune responses, which could influence host susceptibility to infection and other diseases. Unique composition of the gut microbiome, including the predominance of clinically significant eukaryotic viruses like herpesviruses, cytomegalovirus, and human papillomavirus, has been described in both people with HIV (PWH) and men who have sex with men (MSM) vulnerable to HIV. Despite these insights, the rectal virome and the clinical implications of virome–bacteriome–immune interactions in the rectal mucosa remain poorly understood. In this review, we synthesize existing data on the composition of the rectal virome, its interactions with the bacteriome and the immune system, and implications on clinical outcomes in people living with or vulnerable to HIV. We also highlight the gaps and research needed to further explore and unravel these relationships. Full article

The human virome, comprising eukaryotic viruses, bacteriophages, and viral genetic material, is a dynamic component of the microbiome with growing relevance in infectious diseases. This narrative review is structured to: (i) summarize the general composition of the human virome and methodological challenges, including the fraction of unclassified viral “dark matter”; (ii) describe virome alterations in chronic infections; and (iii) explore site-specific virome dynamics across respiratory, intestinal, and genito-urinary tracts in both chronic and acute infections. In chronic viral infections such as HIV, HBV, HCV, and HPV, a recurrent feature is the expansion of Anelloviridae—particularly torque teno virus—reflecting impaired immune surveillance rather than direct pathogenicity, suggesting their potential as surrogate biomarkers of immune competence. Evidence on virome changes in chronic bacterial and parasitic infections remains limited, highlighting a critical knowledge gap. Acute infections are associated with compartment-specific shifts in eukaryotic viruses and bacteriophage communities, often paralleling changes in bacterial populations and inflammatory responses, with implications for disease severity. Despite advances in metagenomic approaches, a substantial proportion of viral sequences remains unclassified, limiting functional interpretation. Nevertheless, virome profiling provides an ecosystem-level perspective, offering insights beyond single-pathogen detection and supporting emerging applications in diagnostics, immune monitoring, prognosis, and infectious disease surveillance. Full article

Nutritional immunity is a major facet of host defense, wherein the host immune system strategically limits pathogen access to critical nutrients, including iron, zinc, vitamins, lipids, and amino acids, to repress microbial proliferation and virulence. This review provides a comprehensive synthesis of the molecular mechanisms that power nutrient immunity, including metal homeostasis, nutrient competition, transporter modulation, hormonal regulation, and direct antimicrobial actions. We examine nutrient-specific strategies employed by the host, such as iron-withholding mechanisms, vitamin deprivation, and copper-mediated toxicity. We also explore how diverse pathogens, including extracellular, intracellular, and eukaryotic pathogens, adapt to these hostile nutritional landscapes through siderophore diversification, regulatory integration, and metabolic rewiring. Comparative genomic analyses reveal convergent evolution in nutrient acquisition systems, illuminating the dynamic arms race between host restriction and microbial evasion. We examine the immunological mechanisms that regulate nutritional immunity. Further, we discuss the translational potential of nutritional immunity, cutting across nutrient-based therapies, host-directed interventions, and emerging diagnostic biomarkers. Finally, we suggest future directions that synergize nutritional immunity with microbiome ecology, global malnutrition, and personalized medicine. By elucidating the interconnection between metabolism and immunity, this review highlights the therapeutic promise of starving or toxifying the pathogen to save the host. Full article

The human virome represents a fundamental yet understudied component of the microbiome, influencing immune regulation and disease. Given the profound immune dysregulation and microbial imbalance associated with HIV infection, understanding virome alterations during HIV and antiretroviral therapy is essential. This narrative review seeks to integrate and discuss the latest evidence regarding the structure and behavior of the human virome in healthy individuals, in the context of HIV infection, and under antiretroviral therapy. A comprehensive literature search was performed in MEDLINE and Google Scholar for peer-reviewed English-language articles published up to November 2025. Studies describing virome composition, diversity, and interactions in people living with HIV, as well as antiretroviral-induced changes, were included. Reference lists of relevant papers were screened to identify additional sources. Data were extracted and synthesized narratively, emphasizing human studies and supported by evidence from primate models where applicable. HIV infection induces profound alterations in the human virome, notably an expansion of eukaryotic viruses such as Anelloviridae, Adenoviridae, and Parvoviridae, accompanied by reduced bacteriophage diversity. Antiretroviral therapy partially restores virome balance but fails to fully re-establish pre-infection diversity, with persistent enrichment of Anelloviridae reflecting incomplete immune reconstitution. Virome perturbations correlate with immune activation, microbial translocation, and inflammation, contributing to comorbidities despite virological suppression. Emerging evidence suggests regimen-specific effects, with integrase inhibitor-based therapies showing more favorable viromic recovery. HIV and antiretroviral therapy profoundly remodel the human virome, with lasting implications for immune homeostasis and chronic inflammation. The ongoing disruption of the virome highlights its promise as both a biomarker and a potential therapeutic target in the management of HIV. Longitudinal, multi-omic studies are needed to clarify the causal role of virome alterations and guide future interventions. Full article

Extracellular vesicles, encompassing eukaryotic exosomes and bacterial outer membrane vesicles (OMVs), play multifaceted roles in mediating host–pathogen interactions. These nanoscale structures act as critical mediators of intercellular communication, transporting diverse bioactive cargo such as miRNAs, cytokines, proteins, and bacterial components. Exosomes contribute to host immunity by delivering antimicrobial agents and modulating inflammatory responses, but they can also be hijacked by pathogens to suppress defenses and promote persistent infection. OMVs, on the other hand, enable bacteria to disseminate virulence factors, deliver toxins directly into host cells, and modulate immune signaling. For example, exosomes from infected macrophages can stimulate dendritic cell activation and T-cell priming, whereas bacterial OMVs have been shown to suppress host immunity or trigger excessive inflammation depending on their molecular cargo. Importantly, OMVs facilitate horizontal gene transfer and nutrient exchange within microbial communities, thereby influencing microbiome composition and adaptation. Together, these complex dynamics position both exosomes and OMVs as central players in immunity and pathogenesis. This review synthesizes recent insights into how host- and pathogen-derived vesicles modulate infection biology and immune responses, while also exploring their potential as diagnostic biomarkers and therapeutic carriers, and discussing current limitations in their clinical translation. Full article

The gut microbiota has emerged as a critical immune–metabolic interface, orchestrating a complex network of interactions that extend well beyond digestion. This highly diverse community of bacteria, viruses, archaea, and eukaryotic microbes modulates host immunometabolism, metabolic reprogramming, and systemic inflammatory responses, thereby shaping human health and disease trajectories. Dysbiosis, or disruption of microbial homeostasis, has been implicated in inflammatory bowel disease, cardiometabolic disorders, neurodegeneration, dermatological conditions, and tumorigenesis. Through the biosynthesis of short-chain fatty acids (SCFAs), bile acid derivatives, tryptophan metabolites, and microbial-derived indoles, the gut microbiota regulates epigenetic programming, barrier integrity, and host–microbe cross-talk, thereby influencing disease onset and progression. In oncology, specific microbial taxa and oncomicrobiotics (cancer-modulating microbes) are increasingly recognized as key determinants of immune checkpoint inhibitor (ICI) responsiveness, chemotherapeutic efficacy, and resistance mechanisms. Microbiota-targeted strategies such as fecal microbiota transplantation (FMT), precision probiotics, prebiotics, synbiotics, and engineered microbial consortia are being explored to recalibrate microbial networks and enhance therapeutic outcomes. At the systems level, the integration of multi-omics platforms (metagenomics, transcriptomics, proteomics, and metabolomics) combined with network analysis and machine learning-based predictive modeling is advancing personalized medicine by linking microbial signatures to clinical phenotypes. Despite remarkable progress, challenges remain, including the standardization of microbiome therapeutics, longitudinal monitoring of host–microbe interactions, and the establishment of robust ethical and regulatory frameworks for clinical translation. Future directions should prioritize understanding the causal mechanisms of microbial metabolites in immunometabolic regulation, exploring microbial niche engineering, and developing precision microbiome editing technologies (CRISPR, synthetic biology). Full article

Extraction of high-quality microbial DNA remains a critical bottleneck in metagenomic research. Environmental samples often produce fragmented DNA and are prone to contaminations that interfere with downstream sequencing, while widely used commercial kits can be prohibitively expensive. Therefore, systematic evaluation of cost-effective alternatives is essential to support large-scale metagenomic studies. In this work, we benchmarked eight commercial DNA extraction kits from Magen, SkyGen, and Sileks against Qiagen reference kits. Four representative sample types were analyzed: freshwater, seafloor sediments, Pacific oyster (Magallana gigas) gut microbiome, and mammalian feces. DNA yield, integrity, purity, PCR inhibitor content, and eukaryotic DNA admixture were assessed. Microbial community composition, alpha diversity, reproducibility, and contamination (“kitome” and “splashome”) were further evaluated using 16S rRNA amplicon sequencing. We revealed that several alternative kits performed comparably or better than the Qiagen reference standard. Magen Soil and Magen Bacterial provided high yields and reproducibility, though the latter produced more fragmented DNA. SkyGen Stool excelled with host-associated samples, while Sileks Soil and Metagenomic kits preserved higher diversity in sediments. Magen Microbiome consistently underperformed. This study identifies multiple cost-effective DNA extraction strategies and provides practical guidance for selecting balanced DNA purification methods for different sample types. Full article

The endangered Rhinogobio ventralis, endemic to the upper Yangtze River, is dependent on captive breeding for its conservation. However, this highly stress-sensitive species is exceptionally susceptible to Ichthyophthirius multifiliis, leading to severe pathology and high mortality in culture. Elevated salinity holds potential for managing key aquaculture pathogens, including Ichthyophthirius multifiliis and Saprolegnia spp. However, its potential unintended ecological consequences remain insufficiently understood. This study evaluated the systemic impacts of 5‰ salinity on the culture environment of the endangered species Rhinogobio ventralis, using integrated 16S/18S rRNA gene sequencing and water quality analysis. The results demonstrated that while salinity treatment effectively reduced the environmental molecular signal of harmful eukaryotes such as Ichthyophthirius and Saprolegnia, it also induced significant ecological shifts: (1) aquatic prokaryotic diversity increased, yet the self-purification capacity of the water was compromised, indicated by elevated dissolved oxygen, nitrate nitrogen, and total nitrogen; (2) in the fish intestinal microbiome, a decline in potentially beneficial taxa (e.g., Exiguobacterium) co-occurred with an enrichment of genera containing potentially pathogenic species (e.g., Staphylococcus and Pseudomonas), collectively suggesting a state of dysbiosis; (3) co-occurrence network analysis revealed that the aquatic microbial community developed greater complexity, while the intestinal network became structurally simplified and more antagonistic. These findings reveal that elevating salinity in freshwater aquaculture systems compromises both host microbiome health and aquatic ecosystem functioning. As such, future aquaculture management should integrate supportive measures like probiotic supplementation to maintain overall system stability. Full article

(1) This study explored Lacticaseibacillus rhamnosus MS27, a newly isolated strain, as a potential probiotic candidate for alleviating the onset and severity of ulcerative colitis (UC). (2) L. rhamnosus MS27 was isolated and subjected to biochemical identification, antibiotic sensitivity testing, and antibacterial activity assessment. Dextran sulfate sodium (DSS) colitis model mice were used to evaluate its alleviating effects. In this study, 16S rRNA microbiome and eukaryotes reference transcriptome analyses were conducted to investigate its impact on intestinal microbial ecology and potential molecular mechanisms. (3) L. rhamnosus MS27 exhibits high acid tolerance at pH 3.23 and maintains a high viable bacterial count for 24 h. It can utilize sucrose, lactose, maltose, inulin, esculin, salicin, and mannitol but not raffinose, and it is sensitive to carbenicillin, erythromycin, tetracycline, chloramphenicol, clindamycin, and penicillin. It effectively increases the abundance of beneficial microbes, particularly Akkermansia, Muribaculaceae, and Limosilactobacillus reuteri (p < 0.05), while significantly reducing microorganisms linked to human pathogens causing diarrhea and gastroenteritis (p < 0.05). Transcriptomic analysis demonstrated that the expression levels of Igkv16-104 and C1qtnf3 were significantly downregulated in the presence of L. rhamnosus MS27 treatment compared to DSS treatment alone (p < 0.05). Further analysis revealed significant differences in genes related to immune functions, antigen presentation, and immune cell markers, indicating potential protein–protein interaction networks, particularly among genes of the major histocompatibility complex (MHC). (4) L. rhamnosus MS27, as a novel strain, demonstrates a significant capacity to alleviate inflammatory phenotypes. L. rhamnosus MS27 exhibits distinctive metabolic characteristics in lactic acid utilization, acetic acid and oleic acid production. Furthermore, it contributes to systemic homeostasis regulation by modulating Turicibacter to link intestinal microbiota composition with host immune function. Full article

The holobiont paradigm, conceptualizing host–microbiome assemblages as functionally integrated entities, has fundamentally altered interpretations of adaptive responses to environmental pressures spanning multiple organizational levels. This review synthesizes the current knowledge on microbiome-host coevolution, focusing on three key aspects. First, it examines the evolutionary origins of holobionts from primordial microbial consortia. Second, it considers the mechanistic basis of microbiome-mediated stress resilience in plants and animals. Finally, it explores the ecological implications of inter-holobiont interactions. We highlight how early microbial alliances (protomicrobiomes) laid the groundwork for eukaryotic complexity through metabolic cooperation, with modern holobionts retaining this plasticity to confront abiotic and biotic stressors. In plants, compartment-specific microbiomes (e.g., rhizosphere, phyllosphere) enhance drought tolerance or nutrient acquisition, while in animals, the gut microbiome modulates neuroendocrine and immune functions via multi-organ axes (gut–brain, gut–liver, etc.). Critically, we emphasize the role of microbial metabolites (e.g., short-chain fatty acids, VOCs) as universal signaling molecules that coordinate holobiont responses to environmental change. Emerging strategies, like microbiome engineering and probiotics, are discussed as tools to augment stress resilience in agriculture and medicine. By framing adaptation as a collective trait of the holobiont, this work bridges evolutionary biology, microbiology, and ecology to offer a unified perspective on stress biology. Full article

Reclaimed land refers to artificially created soil formed by filling in seawater, leading to rapid ecological changes. Undeveloped reclaimed areas offer opportunities to explore previously unknown soil ecological resources. The Shihwa reclaimed land is an undeveloped area where microbiome-based studies of the microbial community have not yet been conducted. The soil from the Sihwa reclaimed land (SR, SL) showed higher pH (8.9), EC (7.5 dS/m), and Na⁺ content (13.4 cmol⁺/kg), but lower levels of organic matter and phosphorus compared to typical agricultural soils (NL, NS). These unfavorable conditions had a negative effect on lettuce growth, as both fresh and dry weights in the SL treatment (32.5 g and 0.39 g, respectively) were significantly lower than those in the NL treatment (40.4 g and 0.45 g). At the phylum level, Actinobacteria (51.6%) dominated the original reclaimed soil (SR), but after lettuce cultivation (SL), there was an increase in Cyanobacteria (25.3%) and Proteobacteria (29.4%). At the order level, Streptomycetales (35.2%) and Bacillales (13.5%) were predominant in SR, whereas in SL, Oscillatoriales (23.5%)—which have photosynthetic ability—as well as organic matter-degrading orders such as Rhodobacterales and Flavobacteriales, became dominant. For the eukaryotic community at the phylum level, Ascomycota was predominant in all samples; however, in NL, the relative proportions of Chlorophyta (22%) and Mucoromycota (8.9%) were higher, indicating increased diversity. At the order level, Eurotiales (28.5%), Hypocreales (20.2%), and Wallemiales (14.4%) were predominant in SR, but after lettuce cultivation, Wallemiales disappeared and Eurotiales increased to 40.0%. Additionally, Glomerellales and Sordariomycetes_o were detected only in SL and NL, suggesting that symbiotic fungal activity in the rhizosphere was promoted. Full article

Protists represent a major component of eukaryotic diversity within the soil microbiome, playing critical roles in mediating carbon and nitrogen cycling and influencing nutrient availability and soil health. Their diversity is shaped by multiple factors, including temperature, pH, organic matter content, and land use. In this study, we investigated the protist diversity in rhizosphere soils from both wild and cultivated date palm varieties. Our results identified nitrate, nitrite, calcium, and carbon content as key soil factors significantly correlated with protist diversity. Only 9.2% (42) of operational taxonomic units (OTUs) were shared across all soil samples, suggesting that these taxa possess traits enabling adaptation to extreme environmental conditions. The dominant protist families belonged to Rhizaria, Alveolata, Amoebozoa, and Archaeplastida, primarily comprising bacterial consumers, alongside taxa from Stramenopiles, Opisthokonta, Hacrobia, and Excavata. At the class level, Filosa-Sarcomonadea, Colpodea, Variosea, Tubulinea, and Chlorophyceae were the most abundant. Filosa-Sarcomonadea and Colpodea were positively correlated with bacterial and fungal genera, suggesting their role as consumers, while Variosea showed a negative correlation with bacteria, reflecting predator-prey dynamics. Notably, the protist community composition in wild date palm rhizosphere soils was distinct from that in cultivated soils, with Opisthokonta being particularly abundant, likely reflecting adaptation to drought conditions. Overall, this study highlights the significant differences in protist diversity and community structure between wild and cultivated date palm ecosystems. Full article

Potato early dying disease complex (PED) leads to premature senescence and rapid decline in potato plants. Unlike potato wilt caused solely by Verticillium species, PED symptoms are more severe due to the synergistic effects of multiple pathogens, including root-lesion nematodes, fungi such as Colletotrichum and Fusarium, and soft-rot bacteria. To investigate the microbiome responsible for PED, soil and stem samples from healthy-looking and symptomatic plants were analyzed using amplicon-targeted next-generation sequencing (Illumina MiSeq and PacBio technologies). Samples were collected from four locations in New Brunswick, Canada from fields previously rotated with barley or oat. Comparative analysis of the bacterial, fungal, and eukaryotic diversity in soil samples showed minimal differences, with only bacterial alpha diversity influenced by the plant health status. Verticillium dahliae was abundant in all soil samples, and its abundance was significantly higher in the stems of diseased plants. Additional fungal species implicated in PED, including Plectosphaerella cucumerina, Colletotrichum coccodes, Botrytis sp., and Alternaria alternata, were also identified in the stems. This study highlights the complex, plant-associated microbial interactions underlying PED and provides a foundation for microbiome-informed disease management strategies. Full article