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PubMed2026

Extensive hidden prophage diversity in Enterobacter species reveals host specificity and local distribution.

Bacteriophages are key drivers of bacterial evolution, particularly through their integration as prophages within host genomes. However, the diversity and host specificity of prophages in relevant pathogens such as Enterobacter species remain poorly characterized. In this study, we revealed the diversity of prophages, mapped their distribution and explored their relationships with their bacterial hosts. We analysed 3,661 prophage sequences identified from the genomes of 20 different Enterobacter species. This analysis uncovered an extensive hidden diversity, comprising 1,617 phage genera and 2,423 phage species - nearly 80% of which were singletons - highlighting an exceptionally rich prophage landscape. We found substantial variation in prophage species richness across host species and isolation sources, with Enterobacter kobei and environmental isolates exhibiting the highest richness. Prophage populations showed strong host specificity and limited cross-species transmission. Moreover, prophages exhibited geographic structuring and significant congruence between host and prophage phylogenies, as well as with the ecological lifestyles of their bacterial hosts. Although we found phages of the same species infecting different host species, these events were infrequent. Finally, bacterial genomes encoded diverse defence systems, mainly PDC-S07, RM type I-II and gabija, whereas only 8.9% of prophages encoded anti-defence systems, mostly anti-CBASS and anti-RM. Overall, this study provides new insights into the diversity of Enterobacter prophages and underscores their ecological and clinical relevance in shaping host adaptation and phage-host dynamics.

Prophages↗

PubMed2025

Development and application of a novel beta-tubulin genotyping tool reveals host-specific transmission cluster in Balantioides coli.

Balantioides coli is a zoonotic ciliated protozoan that infects humans and other mammals. Conventional and ITS-based genotyping approaches have limitations that hinder precise molecular epidemiological investigations. The objective of this study was to develop a new β-tubulin gene-based approach to enhance the detection and genotyping of B. coli. We performed single-cell isolation and whole-genome sequencing on two B. coli isolates from pigs and two from guinea pigs. We then used the β-tubulin gene sequences to design PCR primers for the new genotyping assay. We validated the assay using 56 ITS-confirmed B. coli-positive fecal DNA samples from pigs, cattle, sheep, and guinea pigs. Phylogenetic analyses were conducted using both β-tubulin and ITS sequences. The β-tubulin-based nested PCR assay exhibited 100% detection efficiency and greater specificity than ITS-based methods. Phylogenetic analysis of the β-tubulin gene sequences classified B. coli into three genotypes (I-III). Genotype III appears to be specific to guinea pigs. Genotypes I and II were found across multiple hosts, indicating potential cross-species transmission. Of the five full-length B. coli β-tubulin sequences obtained in this study, 264 polymorphic sites (19.8%) were identified, including both synonymous and non-synonymous mutations. Frequent recombination events within the β-tubulin locus were detected, indicating substantial genetic diversity. Therefore, the β-tubulin gene is a robust marker for genotyping and epidemiological studies of B. coli. The novel nested PCR assay overcomes the limitations of ITS-based methods and has produced data revealing previously unrecognized genetic diversity and host specificity patterns of B. coli.

Tubulin↗

PubMed2024

Impact of effluent parameters and vancomycin concentration on vancomycin resistant Escherichia coli and its host specific bacteriophage lytic activity in hospital effluent.

Vancomycin resistance in bacteria has been classified under high priority category by World Health Organization (WHO) and its presence in hospital effluent is reported to be increasing owing to excess antibiotics use. Among various strategies, bacteriophage has been recently considered as a promising biological agent for combating such antimicrobial resistant bacteria (ARB). However, the influence of effluent's properties on phage-ARB interaction in actual hospital effluent is not completely understood. The present works intends to study this influence of hospital effluent and its parameters on the interaction between vancomycin resistant E. coli (VRE) and its host specific bacteriophage. The isolated VRE was identified by 16S rRNA sequencing, matrix-assisted laser desorption/ionization-time of flight (MALDI - TOF) and whole genome sequencing. The infectivity of phage onto host bacteria was investigated using electron microscopic techniques, dynamic light scattering (DLS), spectrofluorophotometer and confirmed using double agar overlay method. The monovalency and polyvalency of isolated phage against various bacterial species were determined. The phage morphology was identical to T7 phage belonging to Podoviridae. The phage lysis was maximum at pH 7 (90.2%), 37 °C (91.6%) and vancomycin concentration of 50 μg/mL in both synthetic media (89.13%) and effluent (100%). At a maximum vancomycin concentration of 100 μg/mL, decrease in Ca, K, Mg and P (up to 19.70, 14.18, 28, and 15.82% respectively) concentration in effluent was observed due to phage infectivity when compared to control. The whole genome sequencing was performed and the bioinformatics analysis presented the role of mdfA gene encoding the efflux pump in causing vancomycin resistance in E. coli. It also depicted the presence of multiple genes responsible for mercury, cobalt, zinc and cadmium resistance in VRE. These results clearly indicate that bacteriophage mediated combating of VRE is possible in actual hospital effluent and can be used as one of the treatment methods.

Vancomycin↗

PubMed2026

Comprehensive in silico genomics analysis of global trends and host-specific emergence of aminoglycoside resistance in Staphylococcus aureus: a One-Health perspective.

BACKGROUND: Aminoglycosides remain clinically valuable against Staphylococcus aureus. Aminoglycoside resistance in S. aureus represents a critical One Health concern and is primarily driven by aminoglycoside-modifying enzymes (AMEs), which are frequently plasmid-encoded. Although regional studies have provided valuable insights, the global epidemiology of aminoglycoside resistance determinants remains poorly characterized because comprehensive data integrating human, animal, and environmental reservoirs are still lacking. This study addresses this gap by analyzing over 110,000 S. aureus genomes (2000-2025) to map the global resistome, quantify temporal and host-specific trends, and assess the association between genetic determinants and phenotypic resistance. METHODS: We performed a retrospective One Health meta-analysis of 110,309 S. aureus genomes collected between 2000 and 2025 from 128 countries. Genomes were quality-filtered and aminoglycoside resistance determinants were identified using NCBI AMRFinderPlus (v4.0.23). Multilocus sequence typing and host-source harmonization (Human, Animal, Environment, Unknown) enabled clonal and reservoir stratification. Temporal trends in gene prevalence and resistance burden were modeled with robust regression. Geographic and host-associated structuring of key genes was assessed via χ2 and enrichment tests. Machine-learning models (elastic-net, random forests, XGBoost) were benchmarked for minimum inhibitory concentration (MIC) prediction via nested cross-validation, with performance evaluated by mean absolute error, RMSE, and SHAP-based feature importance. All analyses were conducted in R and Python using publicly available, de-identified genomic data. RESULTS: Aminoglycoside resistance-associated genes were dominated by modifying enzyme determinants, with ant(6)-Ia, ant(9)-Ia, aph(3')-IIIa, sat4, aadD1, and aac(6')-Ie/aph(2'')-Ia occurring in 14-22% of isolates worldwide. Temporal analysis revealed significant declines in several major determinants, most notably ant(9)-Ia (-2.22 percentage points per year, p < 0.001), whereas apmA exhibited a non-significant decreasing trend in animal isolates. Host structuring was marked: human clinical isolates concentrated common determinants, while animal and environmental isolates harbored rare alleles (apmA, spw, str, spd). Geographic mapping confirmed near-universal distribution of common genes but focal restriction of rare ones. Publicly available phenotypic data indicated strong activity of amikacin, whereas gentamicin showed a distinct resistant subpopulation that closely corresponded with AME gene carriage. Genotype-phenotype analyses demonstrated strong concordance, with gene-rich complements predicting resistant MIC strata and absence of determinants predicting susceptibility. Analysis across different gene classes revealed frequent co-occurrence of aminoglycoside resistance genes with determinants from other classes, such as mecA, blaZ, and MLS_B, embedding them within multidrug-resistant (MDR) genomic contexts. CONCLUSION: Over 25 years, the prevalence of aminoglycoside resistance-associated genes in S. aureus has declined for several common determinants, while rare veterinary-linked alleles are emerging in animal isolates. Strong genotype-phenotype concordance supports genomic prediction for gentamicin and amikacin, where MIC data are available, although phenotypic confirmation remains essential. The frequent co-occurrence of aminoglycoside resistance genes with other antimicrobial resistance determinants indicates their integration within co-occurrence patterns of MDR genes, defined here as clusters of co-occurring resistance genes often carried on shared mobile genetic elements. These patterns highlight the need for integrated One Health surveillance combining clinical, veterinary, and environmental monitoring with plasmid-context resolution to anticipate emerging threats.

Aminoglycosides↗

PubMed2026

Sulfated mannan of diatoms selects host-specific microbiota in the sunlit ocean.

BACKGROUND: Diatoms, a keystone phylum in Earth's ecosystems, are responsible for substantial oxygen production and the fixation of carbon dioxide in the form of carbohydrates that fuel global food webs. They host diverse prokaryotes, yet how diatoms preferentially recruit those with complementary metabolic traits remains unknown. RESULTS: We discovered that diatoms exude a C6-sulfated α-1,3-mannan that serves as a selective carbon source for adapted Polaribacter. Its structure was resolved using NMR spectroscopy, chromatography, chemical synthesis, and enzymatic dissection. Biochemical, physiological, and structural analyses demonstrated, that specialized Bacteroidota employ a four-enzyme pathway to metabolize this glycan. Metagenomic and transcriptomic data revealed that sulfated mannan utilization loci are globally abundant and actively expressed in surface ocean bacterioplankton. Because this mannan provides only carbon, oxygen, sulfur, and hydrogen, bacteria must obtain other essential elements elsewhere, reinforcing metabolic interdependence. CONCLUSIONS: Together, these results define a chemically specific interaction between diatoms and specialized bacteria that is mediated by a single sulfated polysaccharide and a dedicated four-enzyme degradation pathway. Presence of this pathway in marine metagenomes and transcriptomes indicates that a sulfated mannan from diatoms exerts selection pressure in the sunlit ocean microbiome. Video Abstract.

Diatoms↗

PubMed1976

In vivo germination and host specificity of Nosema algerae in mosquitoes.

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Animals↗

PubMed2026

Species-specific structuring of gut bacterial and fungal communities in honey bees Apis cerana and Apis mellifera.

Honey bee gut microbiome studies have primarily emphasized bacteria, leaving fungal communities comparatively overlooked despite their ecological and functional importance. Whole-genome shotgun metagenomics of Apis cerana and Apis mellifera revealed fungal assemblages dominated by Ascomycota, with Basidiomycota and Microsporidia in minor proportions, alongside gut bacterial communities composed mainly of Pseudomonadota, Bacillota, and Actinomycetota. The bacterial diversity was markedly higher in A. mellifera (Shannon = 5.90; Simpson = 0.98) than in A. cerana (Shannon = 4.01; Simpson = 0.94; p > 0.05), while fungal diversity remained comparable between species (p > 0.05). Beta-diversity analyses revealed strong host-specific clustering for both bacterial (PERMANOVA R2 = 0.7989, p > 0.05) and fungal communities (R2 = 0.7218, p > 0.05), indicating distinct microbial organization driven by host species. Bacterial-fungal co-occurrence patterns exhibited host-specific structuring, suggesting differential inter-kingdom community organization between A. cerana and A. mellifera. Linear Discriminant Analysis Effect Size (LEfSe) identified 93 discriminatory fungal taxa (45 enriched in A. cerana, 48 in A. mellifera), highlighting yeast-dominated signatures in A. mellifera and Basidiomycota-affiliated enrichments in A. cerana. KEGG and CAZy profiling revealed host- and kingdom-specific functional differences, with bacterial communities of A. mellifera showing distinct representation of carbohydrate metabolism and nutrient-cycling functions, while fungal communities exhibited a comparatively narrower functional repertoire. Together, these findings provide a high-resolution view of honey bee bacterial and fungal microbiomes, highlighting strong host-driven divergence in taxonomy, function, and cross-kingdom interactions.

Animals↗

PubMed2025

Understanding Mycobacterium tuberculosis through its genomic diversity and evolution.

Pathogen evolution and genomic diversity are shaped by specific host immune pressures and therapeutic interventions. Analysis of the extant genomes of circulating strains of Mycobacterium tuberculosis, a leading cause of infectious mortality that has co-evolved with humans for thousands of years, can provide new insights into host-pathogen interactions that underlie specific aspects of pathogenesis and onward transmission. With the explosion in the number of fully sequenced M. tuberculosis strains that are now paired with detailed clinical data, there are new opportunities to understand the evolutionary basis for and consequences of M. tuberculosis strain diversity. This review examines mechanistic findings that have emerged from pairing whole genome sequencing data and evolutionary analysis with functional dissection of specific bacterial variants. These include improved understanding of secreted effectors that modulate the properties and migratory behavior of infected macrophages as well as bacterial genetic alterations important for survival within hypoxic microenvironments. Genomic, evolutionary, and functional analyses across diverse M. tuberculosis strains will identify prominent bacterial adaptations to their human hosts and shape our understanding of TB disease biology and the host immune response.

Mycobacterium tuberculosis↗

PubMed2026

Genomes of the ex-type strains of Elsinoë mangiferae and E. perseae, the causal agents of scab on mango and avocado.

Elsinoë species are slow-growing, hemibiotrophic to necrotrophic fungi that cause scab diseases on economically important fruit crops. Genome resources for many host-specific species remain limited. We report high-quality draft genome assemblies for the ex-type strains of Elsinoë mangiferae (CBS 226.50) and E. perseae (CBS 406.34), causal agents of mango and avocado scab, respectively. Among 5 approaches tested, a Nanopore-only NextDenovo assembly produced the most contiguous genomes, yielding 24.5 Mb (E. mangiferae) and 25.1 Mb (E. perseae) assemblies with 13 and 18 contigs, respectively, BUSCO completeness scores of ∼94%, and multiple putative telomere-to-telomere chromosomes. Gene prediction identified 9,134 and 9,243 genes, respectively. Functional annotation revealed enrichment of metabolic and regulatory pathways, including those involved in posttranslational modification, protein transport, and secondary metabolism. Carbohydrate-active enzyme repertoires were small but conserved, consistent with stealth pathogenicity strategies and low plant cell wall degradation. Both genomes encoded large secretomes (>850 proteins), diverse protease repertoires (>300 proteins), Ecp2-like effector proteins, and multiple biosynthetic gene clusters, including clusters with similarity to those associated with elsinochrome and ACT-toxin II biosynthesis, some of which may contribute to host-pathogen interactions and disease development. A large fraction of genes lacked functional characterization, suggesting incomplete databases and/or the presence of lineage-specific genes potentially involved in virulence or host adaptation. These genome resources fill critical gaps for underrepresented Elsinoë species and provide taxonomically anchored references essential for diagnostics, comparative genomics, and research into the molecular basis of host specificity and pathogenicity in scab-causing fungi.

Persea↗

PubMed2025

The ecology and evolution of microbial immune systems: a look on the wild vibrio side.

Natural populations of vibrio beyond the well-studied pandemic strains of Vibrio cholerae, provide a powerful model for investigating the eco-evolutionary dynamics of microbial immune systems. Their genetic diversity, ecological versatility, ease of culturability and the availability of time-series data enable detailed studies of phage-host interactions in natural contexts. This review synthesizes recent advances in vibriophage research, highlighting key findings and emerging tools. High-throughput assays and genomic tools have offered new perspectives on phage specificity, host range and the evolutionary pressures shaping these interactions. Theoretical frameworks, such as arms race and fluctuating selection dynamics, are informed by empirical data from vibrio-phage systems, with time-series sampling providing crucial insights into their temporal and spatial dynamics. A major finding is the role of mobile genetic elements (MGEs) in encoding bacterial defence systems, which shape phage-host coevolution. Discoveries like the phage satellite PICMI illustrate how MGEs facilitate the transfer of antiviral systems, influencing ecological and evolutionary dynamics. The paradox of generalist vibriophages, rare despite their broad host ranges, is also explored. By integrating experimental approaches with field observations, vibriophage research advances microbial ecology and informs sustainable applications in aquaculture and phage therapy, reinforcing vibrios as a versatile model system.This article is part of the discussion meeting issue 'The ecology and evolution of bacterial immune systems'.

Bacteriophages↗

PubMed2026

Bacteriophages Control Epiphytic Pseudomonas syringae Populations in Highbush Blueberry Leaves.

The Pseudomonas syringae complex (Psc) is a group of globally distributed phytopathogens responsible for substantial agricultural losses. Although bacteriophage-based biocontrol has shown promise against Psc, no studies have examined phages targeting blueberry-tropic Psc lineages. Here, we isolated phages infecting Psc strains from diseased highbush blueberry (Vaccinium corymbosum), and evaluated their suitability for biocontrol using a multi-stage screening pipeline incorporating host-range analysis, comparative genomics, environmental stability testing, in vitro antibacterial efficacy assays and ex planta validation. Twelve of the isolated phages exhibited favourable host-range characteristics. Genomic analyses revealed substantial phylogenetic diversity among these candidates but simultaneously identified multiple clonal groups, reducing the collection to eight non-redundant phages spanning five distinct genera. Candidate phages generally retained infectivity under environmentally relevant conditions and exhibited heterogeneous but largely favourable stability profiles. Planktonic killing assays uncovered considerable variation in antibacterial efficacy, but phage performance appeared to be driven by infection compatibility and host-specific factors rather than properties intrinsic to individual phages. Notably, the jumbo phageCB10 emerged as a particularly promising candidate due to its strong antibacterial activity (median GRC = 0.943), favourable environmental stability and unique genomic features. Cocktails containing the most effective candidates produced substantial and longitudinally sustained reductions in epiphytic colonization of detached blueberry leaves by Psc, exceeding five orders of magnitude at peak efficacy and demonstrating robust activity in a biologically relevant ex planta system. Importantly, in vitro antibacterial efficacy was predictive of performance in our ex planta model (r = 0.67; p = 0.0003), supporting the utility of tiered screening approaches for candidate selection. Taken together, these findings establish a framework for the systematic identification and evaluation of phages targeting Psc, and support the development of phage-based interventions for managing plant diseases.

Pseudomonas syringae↗

PubMed2026

Toward simple, rapid, and deep plant proteome analysis with an in-cell proteomics strategy.

While liquid chromatography-mass spectrometry (LCMS) has revolutionized plant proteomics over the past decade, plant sample preparation remains a major challenge due to rigid cell walls, abundant secondary metabolites, and wide dynamic range of protein abundance. These hurdles demand laborious tissue disruption, complex precipitation, and extensive cleanup prior to LCMS analysis, limiting the widespread adoption of proteomic technologies within the plant biology community. To overcome these barriers, we introduced an "in-cell proteomics" strategy that bypasses cell lysis and protein extraction by performing digestion directly inside methanol-fixed cells. We systematically benchmarked this strategy against conventional lysate-based workflows across 4 model plants (Arabidopsis thaliana, Nicotiana benthamiana, Zea mays, and Sorghum bicolor) and 3 tissue types (leaves, pollen, and seeds). Combined with minimal input material and single-shot LCMS, the in-cell approach consistently identified 9,000 to 12,000 proteins from leaves, 7,000 to 9,000 from pollen grains, and approximately 8,000 from seeds. Our comprehensive dataset demonstrates that this in-cell digestion approach substantially simplifies plant sample preparation while delivering proteomic performance equivalent to established workflows. Finally, to demonstrate the biological utility of this approach, we characterized the proteomes of N. benthamiana leaves infected with 2 fungal strains that exhibit different host specificities. Our in-depth proteomic data revealed distinct host response signatures differentiating the host-adapted Colletotrichum destructivum from the nonhost-adapted Colletotrichum sublineola strain. Overall, this study provides a simple, unbiased alternative for plant proteomic analysis that can be readily applied to tackle complex agricultural and physiological challenges in plant biology.

Proteomics↗

PubMed2026

Bacterially produced dsRNA targeting SePGRP-LB reduces population fitness of Spodoptera exigua (Lepidoptera: Noctuidae) and increases its susceptibility to SeMNPV.

The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), is an important agricultural pest, and S. exigua multiple nucleopolyhedrovirus (SeMNPV) is a host-specific biological control agent. However, baculovirus efficacy can be limited by host antiviral responses. S. exigua peptidoglycan recognition protein LB (SePGRP-LB) has been identified as an antiviral immune factor, suggesting that its suppression may increase larval susceptibility to SeMNPV. In this study, bacterially produced double-stranded RNA targeting SePGRP-LB (bac-dsPGRP-LB) was orally delivered to larvae to induce RNA interference. Feeding bac-dsPGRP-LB reduced SePGRP-LB transcript levels by 24.0% to 65.7% over 7 d. SePGRP-LB knockdown prolonged fifth-instar larval development, reduced female pupal weight, shortened male adult longevity and the oviposition period, and decreased fecundity by approximately 51%. Life table analysis further showed significant reductions in the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) following bac-dsPGRP-LB treatment. During SeMNPV infection, co-feeding with bac-dsPGRP-LB significantly suppressed SePGRP-LB expression, increased the SeMNPV genomic load, and reduced larval survival compared with the SeMNPV + bac-dsGFP treatment. These findings identify SePGRP-LB as a promising RNAi target for simultaneously reducing S. exigua fitness and enhancing its susceptibility to SeMNPV under laboratory conditions.

SePGRP-LB↗

PubMed2026

Genomic and ecological systems-thinking framework for pathogenic Leptospira in Puerto Rico.

INTRODUCTION: Leptospirosis is a complex zoonotic disease requiring high-resolution surveillance. A systems-thinking framework was used to connect genomic and ecological data and map the geographic and host-based structuring of co-circulating pathogenic Leptospira lineages in Puerto Rico. METHODS: Forty-four core genomes of L. interrogans, L. borgpetersenii, and L. kirschneri from human, domestic, and wildlife hosts were analyzed. Spatiotemporal and landscape metadata were integrated using root-to-tip regression, isolation-by-distance profiling and calibrated single-nucleotide polymorphism (SNP) thresholds (≤1, ≤5, and ≤10 SNPs) to define transmission clusters. RESULTS: Leptospira species exhibited distinct ecological pathways partitioned by geography, explaining 56% of genomic variance for L. interrogans and 91% for L. borgpetersenii (PERMANOVA). L. interrogans displayed high landscape connectivity across multiple hosts, forming localized networks (≤1 to ≤10 SNPs) that capture active spillovers (human-to-rat linkages at ≤1 SNP) and resolved into rodent host-specific lineages (R2 = 0.34). Conversely, L. borgpetersenii showed spatial and temporal genomic homogeneity and a lack of host-associated structure within an unpartitioned transmission pool dominated by Mus musculus. As a result, fixed genomic thresholds yielded disparate outcomes: L. interrogans resolved into 4 to 5 discrete, expanding clusters, whereas L. borgpetersenii grouped into a single uniform population at the ≤10-SNP threshold. CONCLUSION: Co-circulating pathogenic leptospires occupy distinct ecological niches shaped by varying host restriction and environmental persistence. Fixed genomic thresholds lack universal applicability; effective genomic epidemiological surveillance must employ species-specific threshold calibration to accurately map transmission pathways.

Puerto Rico↗

PubMed2026

Cerium dioxide nanoparticle exposure attenuates mobility-linked antibiotic resistome signatures across the soil-lettuce continuum.

Antibiotic resistance genes (ARGs) are contaminants of emerging concern in agricultural microbiomes. Their association with mobile genetic elements (MGEs) can enhance dissemination across soil-plant interfaces, creating potential environmental and food-chain exposure risks. However, how engineered nanoparticles modulate relative ARG abundance and mobility-linked resistome features in plant-associated microbiomes remains poorly understood. Here, we examined the effects of graded, experimentally elevated cerium dioxide nanoparticle (CeO2 NP) loadings in a soil-lettuce system by integrating compartment-resolved metagenomics, ARG-MGE co-occurrence analysis, putative host-reservoir profiling, transcriptomics, and functional assays. Metagenomic profiling identified 16 ARG types and 125 subtypes and revealed niche-dependent microbiome restructuring under CeO2 NP exposure. Rhizosphere relative ARG abundance showed a negative dose-associated trend, although overall inter-group differences were not significant, whereas leaf endophytes showed a weaker response. Relative MGE abundance decreased significantly in both compartments, and lower assembly-level ARG-MGE co-occurrence reflected fewer ARGs detected in MGE-associated genomic contexts, whereas fewer multi-ARG contigs suggested reduced ARG clustering and potential co-selection. Putative host-reservoir analysis associated key efflux determinants with bacterial families whose relative representation declined following CeO2 NP exposure. Transcriptomic profiling of representative putative ARG hosts revealed host-specific responses, including downregulation of genes involved in central metabolism and Sec-dependent trafficking. Complementary host assays showed reduced apparent envelope permeability and lower recovery of tetracycline-resistant recipient-identity colonies in the plasmid-associated host system. Together, under the tested elevated-loading conditions, CeO2 NP exposure was associated with lower relative ARG signals and weaker mobility-linked resistome features across the soil-lettuce continuum, providing mechanistic insight into nanoparticle-resistome interactions in soil-plant systems.

ARG dissemination↗

PubMed2025

Pooled PPIseq: Screening the SARS-CoV-2 and human interface with a scalable multiplexed protein-protein interaction assay platform.

Protein-Protein Interactions (PPIs) are a key interface between virus and host, and these interactions are important to both viral reprogramming of the host and to host restriction of viral infection. In particular, viral-host PPI networks can be used to further our understanding of the molecular mechanisms of tissue specificity, host range, and virulence. At higher scales, viral-host PPI screening could also be used to screen for small-molecule antivirals that interfere with essential viral-host interactions, or to explore how the PPI networks between interacting viral and host genomes co-evolve. Current high-throughput PPI assays have screened entire viral-host PPI networks. However, these studies are time consuming, often require specialized equipment, and are difficult to further scale. Here, we develop methods that make larger-scale viral-host PPI screening more accessible. This approach combines the mDHFR split-tag reporter with the iSeq2 interaction-barcoding system to permit massively-multiplexed PPI quantification by simple pooled engineering of barcoded constructs, integration of these constructs into budding yeast, and fitness measurements by pooled cell competitions and barcode-sequencing. We applied this method to screen for PPIs between SARS-CoV-2 proteins and human proteins, screening in triplicate >180,000 ORF-ORF combinations represented by >1,000,000 barcoded lineages. Our results complement previous screens by identifying 74 putative PPIs, including interactions between ORF7A with the taste receptors TAS2R41 and TAS2R7, and between NSP4 with the transmembrane KDELR2 and KDELR3. We show that this PPI screening method is highly scalable, enabling larger studies aimed at generating a broad understanding of how viral effector proteins converge on cellular targets to effect replication.

Humans↗

PubMed2025

Phyllosphere microbiomes in grassland plants harbor a vast reservoir of novel antimicrobial peptides and biosynthetic diversity.

INTRODUCTION: The phyllosphere microorganisms colonizing plant surface harbor capacities to synthesize diverse specialized metabolites that mediate communication and interactions with environment and host. However, most known metabolites are derived from a few culturable microorganisms, and the genomic diversity and biosynthetic potential of the vast majority of bacteria associated with plants remain largely unexplored. OBJECTIVES: Here, we aim to explore the genome architecture, biosynthetic ability, and host specific adaptability of grassland ecosystems, uncovering new perspectives on grassland phyllosphere microbial resources. METHODS: We employed ultra-deep metagenomic sequencing, functional analysis, host-associated characterization, and bioactivity assays to explore the phyllosphere microbiome across 221 grassland plant samples representing 45 families. This approach revealed host preference in biosynthetic gene clusters (BGCs) and validated the antimicrobial efficacy of phyllosphere-derived antimicrobial peptides (AMPs). RESULTS: Grassland plant phyllosphere microbiomes encode diverse BGCs. We identified 885,396 potential AMPs from over 68 million non-redundant gene sequences. Then, we reconstructed hundreds of near-complete genomes from phyllosphere metagenomes, and 32.61 % of reconstructed genomes were identified as unclassified genomes, primarily within Pseudomonadota, Actinomycetota, Bacillota and Bacteroidota phyla. Of the near-complete genomes, 91.97 % of the BGCs and 99.76 % of the identified AMPs were previously uncharacterized. Host phylogenetic analysis revealed functional divergence. Poaceae-associated Pseudomonas genomes contain an average of 28 BGCs, significantly higher than those in Asteraceae-associated genomes (mean = 14.76, P = 0.033). Similarly, Poaceae-associated Pantoea genomes carried an average of 9 BGCs, exhibiting significant enrichment compared to genomes from Asteraceae (mean = 7.13, P = 6.1e-05), Lamiaceae (mean = 7, P = 0.015), Ranunculaceae (mean = 8.22, P = 0.0053), and Rosaceae (mean = 7.75, P = 0.00069). ParaFit analyses further confirmed that host phylogeny significantly structures microbial functional repertoires, with intra-family hosts sharing more KEGG pathways than inter-family hosts. These results suggest that host evolutionary relationships are associated with metabolic specialization in phyllosphere microbiomes. All 13 AMPs synthesized via solid-phase peptide synthesis demonstrated antimicrobial activity, inhibiting the growth of at least one tested bacterial strain. CONCLUSION: This study demonstrates the promise of grassland plant phyllosphere microbiome as a rich source for novel antimicrobial agents.

Antimicrobial Peptides↗

PubMedDate not supplied

[Incidence of Arbovirus isolated from mosquitoes in the forest region of South Cameroun, region of Yaoundé ].

The authors give results of a survey of arboviruses isolated from mosquitoes in the neighborhood of Yaoundé, Southern Cameroon, from 1964 to 1972. During this period of nine years 127.520 female mosquitoes including at least 72 species were collected and processed for attempt of virus isolation. 55 strains belonging to 12 viral types were recovered from at least 19 species of mosquitoes. The appearance of different viruses over the years was quite intermittent. A possible reason for this is the need for viruses to move in search of susceptible vertebrate hosts. There was not definite evidence of vector host specificity except likely for Anopheles gambiae s. l. as a vector of Tataguine. However, among the more infected species, some ones show by their host preferences they could be true vectors of the viruses isolated from them.

Aedes↗