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At least 19 recordsLinked to original sources
PubMed2025

A comprehensive reference catalog of human skin DNA virome reveals novel viral diversity and microenvironmental influences.

UNLABELLED: Human skin serves as a dynamic habitat for a diverse microbiome, including a complex array of viruses whose diversity and roles are not fully understood. A total of 2,760 skin metagenomes from 6 published skin studies were collected. A skin virome catalog was constructed using standard methods in the viromics field. Viral characteristics were identified through cross-cohort meta-analysis and used to characterize viral features across different skin environments. We identified 20,927 viral sequences, which clustered into 2,873 viral operational taxonomic units (vOTUs), uncovering a substantial breadth of viral diversity on human skin. The results also highlight significant differences in viral communities that are associated with varying skin microenvironments. The oily skin is enriched in Papillomaviridae, the dry skin area is enriched in Autographiviridae and Inoviridae, and the moist skin is enriched in Herelleviridae. We also investigated the relationship between bacteriophages and bacteria on the skin surface. We found that skin bacteria such as Pseudomonas, Klebsiella, and Staphylococcus are predicted to be infected by phages from the class Caudoviricetes. This comprehensive skin DNA viral catalog significantly advances our understanding of the virome's role within the skin ecosystem. IMPORTANCE: This study presents a comprehensive reference catalog of the human skin DNA virome, constructed from 2,760 metagenomic datasets collected globally. It identified 20,927 viral sequences, with 90.85% representing previously unknown viruses, greatly expanding our understanding of skin viral diversity. The findings reveal significant differences in viral communities between distinct skin microenvironments (oily, dry, and moist) and highlight close interactions between bacteriophages and their bacterial hosts, suggesting a potential role for the virome in maintaining microbial balance and skin health. This extensive skin viral catalog constitutes a crucial resource for future epidemiological and therapeutic research, potentially facilitating the development of novel phage therapies and diagnostic markers for skin disorders.

Humans↗
PubMed2025

Metagenomic analysis of viral diversity in Portuguese bats.

Bats are highly diverse mammals and known reservoirs of numerous zoonotic viruses. Their role in the ecology of emerging infectious diseases continues to be of significant interest. This study aimed to evaluate the occurrence of coronaviruses (CoVs) in Portuguese bats and predict the affinity of their spike proteins with the aminopeptidase N (APN) receptor of several host species. The study also explored the viral diversity in bat samples using metagenomic sequencing. Ten bats (five Myotis myotis and five Miniopterus schreibersii) were captured at an underground roost in 2022 (Central Portugal), and fecal samples, oral, and anal swabs were collected (n = 27). A Pan-CoV nested RT-PCR was used for initial screening, followed by viral metagenomic sequencing of all fecal samples and one CoV-positive buccal swab. In silico protein docking studies were performed between a Portuguese bat CoV spike protein and APNs of bats, pigs, and humans. Pan-CoV nested RT-PCR identified three positive samples: two fecal samples and one buccal sample. Metagenomic sequencing allowed us to determine two near complete CoV genomes. Protein docking predicted strong binding of this spike protein to bat, porcine, and human APN receptors. Metagenomics also identified picornaviruses, adenovirus, and dependoparvovirus in fecal samples. This study reports the first near complete genome sequences of two members of the Alphacoronavirus genus from a Portuguese bat The identification of other viral families highlights the diverse virome of these cave-dwelling bat species. Protein docking studies suggest a potential for cross-species transmission of this bat CoV between bats, porcines and humans, though further research is needed to confirm these interactions.

Animals↗
PubMed2025

The Aggregated Gut Viral Catalogue (AVrC): A unified resource for exploring the viral diversity of the human gut.

The growing interest in the role of the gut virome in human health and disease, has led to several recent large-scale viral catalogue projects mining human gut metagenomes each using varied computational tools and quality control criteria. Importantly, there has been to date no consistent comparison of these catalogues' quality, diversity, and overlap. In this project, we therefore systematically surveyed nine previously published human gut viral catalogues. While these catalogues collectively screened >40,000 human fecal metagenomes, 82% of the recovered 345,613 viral sequences were unique to one catalogue, highlighting limited redundancy between the ressources and suggesting the need for an aggregated resource bringing these viral sequences together. We further expanded these viral catalogues by mining 7,867 infant gut metagenomes from 12 large-scale infant studies collected in 9 different countries. From these datasets, we constructed the Aggregated Gut Viral Catalogue (AVrC), a unified modular resource containing 1,018,941 dereplicated viral sequences (449,859 species-level vOTUs). Using computational inference tools, annotations were obtained for each vOTU representative sequence quality, viral taxonomy, predicted viral lifestyle, and putative host. This project aims to facilitate the reuse of previously published viral catalogues by the research community and follows a modular framework to enable future expansions as novel data becomes available.

Humans↗
PubMed2026

Virome metatranscriptomic profiling of birch pollen reveals a diverse viral community.

INTRODUCTION: Viruses are increasingly recognized as integral components of plant-associated biological systems. However, their occurrence and diversity in the reproductive tissues of woody plants remain poorly understood. Birch (Betula spp.) produces large quantities of wind-dispersed pollen that can travel over long distances and may harbour viruses or virus-derived nucleic acids originating from the host plant and/or its associated microbiota. METHODS: We investigated the virome of birch pollen collected from trees growing in central and suburban Berlin, Germany. Metatranscriptomic analyses were performed on pooled pollen samples collected in 2020. These analyses were complemented by RT-PCR screening of individually processed pollen samples collected in 2025 from resampled trees. Primer walking was additionally used to recover an extended genome sequence of a pollen-associated birch toti-like virus. RESULTS: Multiple virus-associated contigs were identified in both pooled metatranscriptomic datasets. These included sequences corresponding to the cherry leaf roll virus (CLRV), the birch idaeovirus (BIV) and the birch toti-like virus (BTLV), as well as additional virus-like contigs provisionally assigned to lineages related to the Orthototiviridae, Botourmiaviridae, Endornaviridae, and Chrysoviridae families. RT-PCR analysis of individually processed pollen samples confirmed the continued detection of CLRV, BIV, and BTLV within the Berlin sampling framework. A near-complete genome sequence was recovered from a pollen-derived BTLV isolate from Berlin, showing high amino acid sequence identity to a recently described leaf-derived BTLV isolate from the United States. DISCUSSION: These findings demonstrate that birch pollen harbours a diverse assemblage of plant- and/or microbiome-associated viruses and expand the known tissue distribution and geographic range of BTLV. More broadly, they establish pollen as an underexplored ecological niche for virome research and provide a foundation for future studies on the ecology, transmission dynamics, and epidemiological significance of pollen-associated and pollen-transmitted viruses.

Betula↗
PubMed2025

Broad geographical circulation of a novel vesiculovirus in bats in the Mediterranean region.

Bats are the natural reservoirs for a variety of emerging and re-emerging viruses. Among them, rabies virus (genus Lyssavirus, family Rhabdoviridae) is one of the first and most emblematic described in these animals. Since its first description, several new bat lyssaviruses have been regularly identified. In addition to lyssaviruses, other bat rhabdoviruses have also been discovered, including members of the genera Vesiculovirus, Ledantevirus and, more recently, Alphanemrhavirus and Tupavirus. However, the family Rhabdoviridae is one of the most abundant and diverse viral families, with 434 officially recognized species, divided into 5 subfamilies and 56 different genera. The number of rhabdoviruses associated with bats is therefore probably higher than that currently available. In this study, we first developed and validated a combined nested RT-qPCR technique (pan-rhabdo RT-nqPCR) dedicated to the broad detection of animal rhabdoviruses. After validation, this technique was used for a large retrospective screening of archival bat samples (n = 1962), including blood (n = 816), brain (n = 723) and oral swab (n = 423). These samples were collected from various bat species over a 12-year period (2007-2019) in 9 different countries in Europe and Africa. A total of 23 samples (1.2%) from bat species Miniopterus schreibersii, Rhinolophus euryale and Rhinolophus ferrumequinum tested positive for rhabdovirus infection, including 17 (2.1%) blood and 6 (1.4%) oral swab samples, all collected from bats originating from the Mediterranean region. Complete virus genome sequences were obtained by next-generation sequencing for most of the positive samples. Molecular and phylogenetic analysis of these sequences demonstrated that the virus isolates, named Mediterranean bat virus (MBV), were closely related and represented a new species, Mediterranean vesiculovirus, within the genus Vesiculovirus. MBV was more specifically related to other bat vesiculoviruses previously described from China and North America, together clustering into a distinct group of bat viruses within this genus. Interestingly, our results suggest that MBV is widespread, at least in the western part of the Mediterranean region, where it circulates in the blood of several bat species. These results expand the host range and viral diversity of bat vesiculoviruses, and pave the way for further studies to determine the transmission route and dissemination dynamics of these viruses in bat colonies, as well as to assess their potential threat to public health.

Animals↗
PubMed2024

Soil keystone viruses are regulators of ecosystem multifunctionality.

Ecosystem multifunctionality reflects the capacity of ecosystems to simultaneously maintain multiple functions which are essential bases for human sustainable development. Whereas viruses are a major component of the soil microbiome that drive ecosystem functions across biomes, the relationships between soil viral diversity and ecosystem multifunctionality remain under-studied. To address this critical knowledge gap, we employed a combination of amplicon and metagenomic sequencing to assess prokaryotic, fungal and viral diversity, and to link viruses to putative hosts. We described the features of viruses and their potential hosts in 154 soil samples from 29 farmlands and 25 forests distributed across China. Although 4,460 and 5,207 viral populations (vOTUs) were found in the farmlands and forests respectively, the diversity of specific vOTUs rather than overall soil viral diversity was positively correlated with ecosystem multifunctionality in both ecosystem types. Furthermore, the diversity of these keystone vOTUs, despite being 10-100 times lower than prokaryotic or fungal diversity, was a better predictor of ecosystem multifunctionality and more strongly associated with the relative abundances of prokaryotic genes related to soil nutrient cycling. Gemmatimonadota and Actinobacteria dominated the host community of soil keystone viruses in the farmlands and forests respectively, but were either absent or showed a significantly lower relative abundance in that of soil non-keystone viruses. These findings provide novel insights into the regulators of ecosystem multifunctionality and have important implications for the management of ecosystem functioning.

Soil Microbiology↗
PubMed2026

Viral community structure in New Zealand's aquatic birds is associated with scavenging behavior.

Wild migratory birds play a major role in the global spread of viruses, yet the ecological drivers underpinning viral diversity and transmission, particularly host behavior, remain poorly understood. Aotearoa/New Zealand provides a powerful system to address this, including unique species that reflect its geographical isolation, yet with international connections provided by migratory birds across the East Asian-Australasian Flyway and Antarctic regions. Herein, we conducted a large-scale metatranscriptomic survey of wild birds across New Zealand and its subantarctic islands, in which we collected 1,348 samples from 690 individuals across 31 host species spanning four avian orders. We identified 118 avian viruses from 17 families, including 107 novel species, expanding our knowledge of avian viral diversity. Notably, viral community composition was most strongly associated with bird scavenging behavior, which explained more variation than host taxonomy, geography, or migratory status. Scavenging birds and opportunistic scavengers harbored more diverse viromes than non-scavengers, consistent with increased viral exposure across trophic levels. This was supported by the detection of 12 mammalian-associated viruses, primarily in scavengers, including hedgehog hepatovirus, rabbit hemorrhagic disease virus 2, and sea lion astroviruses, with host sequence data confirming dietary origin. We also detected viruses of epidemiological and evolutionary interest, including a low-pathogenic avian influenza A(H1N9) virus from red knots (Calidris canutus) and a divergent tobanivirus from Auckland Island teal (Anas aucklandica), which represented the first putative avian member of the Tobaniviridae. These findings suggest that virome structure in wild birds is associated with scavenging behavior, thus highlighting the importance of incorporating host ecology into viral surveillance and risk assessment.

New Zealand↗
PubMed2025

Metagenomics reveals cryptic circulation of zoonotic viruses in Nigeria.

Zoonotic spillover events pose an ongoing threat to global health, with historic and recent viral diseases of international concern emerging from animal reservoirs 1-6. In Nigeria, limited surveillance of animal hosts at the human and animal interface continues to hinder our understanding of viruses that are cryptically circulating in animals near human dwellings with potential for consequential spillover events. We performed unbiased metagenomic next-generation sequencing (mNGS) on tissue and swab samples collected from 240 individual animals across 11 taxa (rodents, shrews, bats, goats, sheep, pigs, dogs, cats, chickens, cattle egrets, and lizards) in two Lassa-affected Nigerian states (Ondo and Ebonyi). Host-depleted sequencing reads were assembled into contigs, taxonomically classified, and subjected to phylogenetic analyses to characterize viral diversity, host associations, and evidence of cross-species transmission. Across all samples, we identified 214 distinct viral taxa spanning 33 families, of which 41% (n = 83) represent novel species by ICTV criteria. Positive-sense RNA viruses dominated (Coronaviridae, Picornaviridae, Astroviridae), followed by negative-sense RNA, single- and double-stranded DNA, and double-stranded RNA viruses. Notably, human-associated enteroviruses-including Hepatitis A virus (genotype 1b), echoviruses, coxsackieviruses, and noroviruses-were detected in goats, pigs, dogs, and chickens, indicating cryptic circulation of human pathogens in peridomestic and domesticated animals. Phylogenetic reconstructions revealed multiple cross-species viral sharing events, particularly among rodents, goats, sheep, and pigs, and extensive recombination within Nigerian Betacoronavirus 1 lineages. Interestingly we found a putative novel avian like coronavirus in rodents, goats and sheep. Ecological modelling demonstrated that host species identity, sample type, and sampling effort were primary drivers of viral richness and abundance, and that higher overall viral diversity strongly predicted cross-species transmission potential. Our integrated mNGS approach uncovered a rich and dynamic virome within animals inhabiting human-dominated environments in Nigeria, including undetected circulation of human enteric viruses. These findings underscore the importance of broad-taxonomic, real-time surveillance at human-animal interfaces to inform early-warning systems and pandemic preparedness, particularly in low-resource settings.

Journal Article↗
PubMed2024

Large language models improve annotation of prokaryotic viral proteins.

Viral genomes are poorly annotated in metagenomic samples, representing an obstacle to understanding viral diversity and function. Current annotation approaches rely on alignment-based sequence homology methods, which are limited by the paucity of characterized viral proteins and divergence among viral sequences. Here we show that protein language models can capture prokaryotic viral protein function, enabling new portions of viral sequence space to be assigned biologically meaningful labels. When applied to global ocean virome data, our classifier expanded the annotated fraction of viral protein families by 29%. Among previously unannotated sequences, we highlight the identification of an integrase defining a mobile element in marine picocyanobacteria and a capsid protein that anchors globally widespread viral elements. Furthermore, improved high-level functional annotation provides a means to characterize similarities in genomic organization among diverse viral sequences. Protein language models thus enhance remote homology detection of viral proteins, serving as a useful complement to existing approaches.

Viral Proteins↗
PubMed2024

Diverse RNA viruses discovered in multiple seagrass species.

Seagrasses are marine angiosperms that form highly productive and diverse ecosystems. These ecosystems, however, are declining worldwide. Plant-associated microbes affect critical functions like nutrient uptake and pathogen resistance, which has led to an interest in the seagrass microbiome. However, despite their significant role in plant ecology, viruses have only recently garnered attention in seagrass species. In this study, we produced original data and mined publicly available transcriptomes to advance our understanding of RNA viral diversity in Zostera marina, Zostera muelleri, Zostera japonica, and Cymodocea nodosa. In Z. marina, we present evidence for additional Zostera marina amalgavirus 1 and 2 genotypes, and a complete genome for an alphaendornavirus previously evidenced by an RNA-dependent RNA polymerase gene fragment. In Z. muelleri, we present evidence for a second complete alphaendornavirus and near complete furovirus. Both are novel, and, to the best of our knowledge, this marks the first report of a furovirus infection naturally occurring outside of cereal grasses. In Z. japonica, we discovered genome fragments that belong to a novel strain of cucumber mosaic virus, a prolific pathogen that depends largely on aphid vectoring for host-to-host transmission. Lastly, in C. nodosa, we discovered two contigs that belong to a novel virus in the family Betaflexiviridae. These findings expand our knowledge of viral diversity in seagrasses and provide insight into seagrass viral ecology.

RNA Viruses↗
PubMed2026

Dental wastewater reveals a hidden reservoir of oral bacteriophage diversity.

Bacteriophages (phages) are being explored as alternatives or complements to antibiotics because of their ability to selectively kill bacterial pathogens. However, phages that infect many oral bacteria remain undiscovered. Here, we discovered that dental wastewater harbors previously underexplored phage diversity. Viral particles concentrated from dental wastewater displayed diverse morphologies, including abundant filamentous phage-like particles. Deep long-read metagenomic sequencing of concentrated viral particles generated 7.4 billion bases of sequence data and yielded 255 medium- to high-quality viral operational taxonomic units (vOTUs), including 46 predicted complete genomes. Comparison with large phage databases revealed that 63 of these 255 vOTUs had no detectable match, indicating that extensive sequencing of dental wastewater substantially expands the number of potential bacteriophages associated with the human oral microbiome. Host prediction linked many vOTUs to oral-associated bacterial taxa, including species with few or no previously reported phages, such as Porphyromonas gingivalis, Tannerella forsythia, and Candidatus Saccharibacteria. Functional annotation identified diverse genes associated with antiphage defense systems within a subset of vOTUs, suggesting that oral phages may contribute to the movement of genes encoding bacterial immune functions within the oral microbiome. Together, these findings expand the known oral phageome and show that dental wastewater contains a largely untapped diversity of phages.IMPORTANCEThe human oral cavity contains a diverse microbial community, but the bacteriophages (phages) that infect many oral bacteria remain poorly characterized. This gap limits our understanding of how phages shape oral microbial communities. Here, we show that dental wastewater is an underexplored source of oral phage diversity. Deep long-read metagenomic sequencing revealed 255 medium- to high-quality phage operational taxonomic units, many of which are not present in existing oral phage databases. These genomes include predicted phages of periodontal disease-associated bacteria and other oral taxa with few or no known phages. Dental wastewater therefore expands the known human oral phageome and reveals candidate phages linked to bacteria associated with oral health and disease.

Bacteriophages↗
PubMed2026

A small viral protein suppresses immune amplification by two distinct mechanisms.

Diverse viral suppressors of RNA interference (RNAi) and RNA silencing (VSRs) interact directly with core protein and/or RNA components of the host RNAi pathway. However, the specific counter-defense function of any VSR biochemical activity is fully validated only when it is shown as essential for viral infection in the wild-type but not mutant hosts defective in antiviral RNAi. Here, we investigated the role of VSR activities for direct binding to small-interfering RNA duplexes (siRNA), long double-stranded RNA (dsRNA), or RNA-dependent RNA polymerase 1 (RDR1) during plant infection by wild-type and mutant cucumber mosaic virus (CMV), a positive-strand RNA virus expressing the 110-residue 2b protein as its VSR. We demonstrate that a C-terminally truncated 2b mutant (2b1-93) active in direct binding to siRNA and dsRNA, but not RDR1, was able to suppress the amplification of virus-derived siRNAs (vsiRNA) and antiviral RNAi mediated by RDR6, but not RDR1. By contrast, an N-terminally truncated 2b mutant (2b18-110) inactive in direct binding to siRNA or dsRNA was able to suppress vsiRNA amplification and antiviral RNAi mediated by RDR1, but not RDR6, and was less effective to promote systemic CMV infection and disease development than 2b1-93. Together, our results show that whereas RDR1 suppression requires direct binding of VSR-2b to RDR1, but not siRNA or dsRNA, RDR6 suppression depends on direct binding to siRNA and dsRNA, but not RDR1. Therefore, CMV, through its VSR-2b, suppresses two parallel vsiRNA amplification pathways by distinct molecular mechanisms, and this unique property may account for the unusually wide host range of CMV.IMPORTANCEHost amplification of antiviral immunity is essential for robust control of viral infections. However, little is known about the mechanisms that viruses have evolved to suppress immune amplification in plants. Here, we characterized whole plant infection by cucumber mosaic virus (CMV) with its viral suppressor of RNA interference (RNAi) mutated to become inactive in direct binding to small-interfering RNA duplexes (siRNA), long double-stranded RNA (dsRNA), or RNA-dependent RNA polymerase 1 (RDR1). We demonstrate maximal suppression of both RDR1- and RDR6-mediated antiviral RNAi amplification by the CMV 2b protein, a viral suppressor of RNAi (VSR). Notably, whereas RDR1 suppression requires direct binding of 2b to RDR1 but not siRNA or dsRNA, RDR6 suppression depends on direct binding to siRNA and dsRNA, but not RDR1. Our findings reveal a novel counter-defense strategy evolved by a wide host range positive-strand RNA virus to suppress two pathways of immune amplification by distinct mechanisms.

Cucumovirus↗
PubMed2026

Complete Genome Sequence of Atractylodes virus A, a Novel Carlavirus Infecting Atractylodes lancea.

Atractylodes lancea is an important medicinal crop, but viral diseases have become increasingly severe in recent years. Viruses in the genus Carlavirus are common plant pathogens that are primarily transmitted by aphids and can cause stunted growth and reduced yields in their host plants. In this study, a novel carlavirus, tentatively named Atractylodes virus A (AVA), was identified from A. lancea plants exhibiting virus-like symptoms. The full-length genome of AVA is 8,817 nt in length and contains six open reading frames, displaying the typical genomic organization of the genus Carlavirus. The replicase and CP exhibit 53.43% and 56.72% amino acid identity, respectively, with those of previously characterized carlaviruses, indicating that AVA represents a novel species in the genus Carlavirus. This study expands our understanding of viral diversity in A. lancea and provides a scientific foundation for the prevention and control of viral diseases as well as for resistance breeding.

Genome, Viral↗
PubMed2026

Uncovering viral protein acquisition events and human-specific folds with pairwise comparisons of predicted protein structures.

Pairwise sequence comparisons are at the center of molecular evolutionary analyses. However, viral pairwise comparisons are challenging because extreme mutation rates and evolutionary pressure cause genomes to diverge rapidly, limiting detectable sequence similarity to fewer than 3% of virus pairs. To overcome these limitations, we compared viruses based on structural similarity, using predicted protein structures from ColabFold and Foldseek to define protein fold clusters. We represented each virus genome by its protein structural content. Pairwise similarities between viruses were then quantified using the Jaccard index based on the presence or absence of protein fold clusters. Using a recently established viral protein fold database, we compared all pairs of eukaryotic viruses in RefSeq. This approach increased the proportion of comparable viral genome pairs from 2.4% to 16.5%. Using this protein-fold representation of viruses, we were able to accurately predict viral families with an average sensitivity of 85.9%. Investigation of viral families showing limited sensitivity with this approach uncovered a laterally transferred structural cluster (Rep/NS1) broadly shared across diverse viral families and found in the avian lineage of adenoviruses. Sequence homology suggests that this Rep was acquired from Parvoviridae, but the protein is mutant in the ATPase active site, indicating possible exaptation toward a purely DNA-binding function. In Gammapapillomaviruses, several E4 clusters were associated with human tropism. In summary, by representing viruses with structural protein clusters, we can classify highly divergent viruses, trace lateral gene transfer, and uncover features associated with viral host range.

Humans↗
PubMed2025

Molecular characterisation of a novel citrus-infecting emaravirus, citrus emaravirus 1.

The application of high-throughput sequencing (HTS) has accelerated the discovery of novel viruses and the genome sequencing of poorly characterised viruses in fruit crops, revealing a greater complexity of plant viromes than previously understood. Here, we report the identification and genomic characterisation of a novel emaravirus, tentatively named "citrus emaravirus 1" (CiEV1), from Citrus limon leaves collected in the North West Province of South Africa. HTS analysis identified contigs corresponding to the four conserved emaravirus genomic segments (RNA1-RNA4), each encoding characteristic proteins: RNA-dependent RNA polymerase, glycoprotein, nucleocapsid, and movement protein. Comparison of terminal sequences and phylogenetic analysis suggest placing CiEV1 within clade D of the genus Emaravirus (family Fimoviridae). To date, no association with symptoms has been identified. This is the first report of an emaravirus detected in citrus, expanding the known host range of the genus and contributing to the growing evidence of viral diversity in citrus. Further investigation is required to determine the epidemiological significance of CiEV1 in citrus orchards.

Citrus↗
PubMed2024

Tapping the treasure trove of atypical phages.

With advancements in genomics technologies, a vast diversity of 'atypical' phages, that is, with single-stranded DNA or RNA genomes, are being uncovered from different ecosystems. Though these efforts have revealed the existence and prevalence of these nonmodel phages, computational approaches often fail to associate these phages with their specific bacterial host(s), while the lack of methods to isolate these phages has limited our ability to characterize infectivity pathways and new gene function. In this review, we call for the development of generalizable experimental methods to better capture this understudied viral diversity via isolation and study them through gene-level characterization and engineering. Establishing a diverse set of new 'atypical' phage model systems has the potential to provide many new biotechnologies, including potential uses of these atypical phages in halting the spread of antibiotic resistance and engineering of microbial communities for beneficial outcomes.

Bacteriophages↗
PubMed2027

Protocol for Detecting and Sequencing Chikungunya Virus from Field-Collected Mosquitoes.

Arboviral diseases represent a major public health challenge, especially in tropical regions where environmental conditions may favor the proliferation and spread of mosquito vectors. Thus, early and accurate detection of chikungunya virus (CHIKV) in mosquito populations can be a valuable tool for effective surveillance of circulating variants and for identifying new viral introductions. Given the challenges of detecting arboviruses in field-captured mosquitoes, we describe an integrated workflow for CHIKV molecular detection and whole-genome sequencing. This protocol includes mosquito homogenization using a bead-based mechanical disruptor, RNA extraction using TRIzol reagent with minor modifications, molecular screening using CHIKV-specific RT-qPCR, and whole-genome amplification followed by sequencing on Illumina platforms. Despite the protocol being optimized for individual mosquitoes, it results in high-quality RNA suitable for both entomological surveillance and genomic analysis. As this protocol allows recovery of complete CHIKV genomes from mosquito specimens, it can serve as a basis for genomic epidemiology studies, enabling monitoring of viral diversity and lineage dynamics, and facilitating early detection of emerging variants to support timely and targeted public health interventions in endemic and at-risk regions.

Animals↗
PubMed2026

Identification and masking of artifactual and misleading within-host variants in deep-sequencing SARS-CoV-2 data.

Deep-sequencing data are increasingly used to study within-host viral diversity and to inform evolutionary inference. For SARS-CoV-2, analyses based on intra-host single-nucleotide variants (iSNVs) have been widely applied to quantify within-host diversity and infer transmission dynamics. However, these applications critically depend on the reliable identification of low-frequency variants, which remain vulnerable to systematic and technical artifacts. In this study, we show that recurrent artifactual iSNVs are common in large-scale SARS-CoV-2 sequencing data and can persist even under conservative minor allele frequency thresholds. Using data from the UK's Office for National Statistics COVID-19 Infection Survey, we demonstrate that such artifacts are predominantly sequencing center-specific rather than primer-specific. Each center exhibits a modest, distinct set of recurrent artifactual variants showing little overlap with sites routinely masked at the consensus level. To address this, we developed a systematic, dataset-aware framework that uses recurrence within sequencing datasets to identify small, noise-adapted sets of artifactual iSNVs to mask. Applying this framework reduces spurious sharing of low-frequency variants between samples and qualitatively alters downstream inferences, including estimates of within-host diversity and transmission bottleneck sizes. Although this study focused on SARS-CoV-2, it is likely that recurrent artifactual iSNVs will be problematic for other viruses as mass-sequencing becomes increasingly routine. Together, these findings highlight the importance of explicit, dataset-aware artifact control for robust inference from within-host variation, particularly as genomic studies increasingly seek to exploit sub-consensus diversity in rapidly evolving pathogens.

Humans↗