#Genetic characterization of the #marmot gut #virome in high-altitude #Qinghai Province and identification of novel #viruses with zoonotic potential

ABSTRACT

The high-altitude ecosystems of Qinghai Province, China, harbor unique viral communities shaped by extreme environmental conditions and host adaptations. This study presents a comprehensive genetic characterization of the marmot gut virome, revealing novel viral strains with zoonotic potential. Using viral metagenomics, we analyzed intestinal contents from 70 marmots collected from Chengduo and Maqin counties. Sequencing on the Illumina NovaSeq 6000 platform identified 19 viral genomes belonging to four major families: Adenoviridae, Astroviridae, Parvoviridae, and Picornaviridae, along with four novel circular Rep-encoding single-stranded DNA (CRESS DNA) viruses. Phylogenetic analyses demonstrated close relationships between marmot-derived strains and viruses from humans, bats, and other mammals, highlighting potential cross-species transmission risks. Notably, bat-associated adenoviruses showed closer phylogenetic proximity to human strains, while novel parvoviruses formed a distinct clade within the Dependoparvovirus genus. The discovery of a novel astrovirus with low sequence similarity to known genera underscores the need for taxonomic reclassification. Additionally, a novel picornavirus related to Sapelovirus and four divergent CRESS DNA viruses were identified, expanding our understanding of viral diversity in high-altitude rodents. These findings emphasize the role of marmots as viral reservoirs and highlight the importance of high-altitude ecosystems as hotspots for zoonotic pathogen emergence. This study provides critical insights into viral evolution, host adaptation, and zoonotic risks, advocating for integrated surveillance strategies to mitigate future spillover events.

IMPORTANCE

Viruses are the most abundant and diverse biological entities on Earth, yet their presence in wildlife from extreme environments remains poorly understood. High-altitude ecosystems, shaped by harsh conditions like intense UV radiation and low oxygen levels, create unique settings for virus evolution. This study is the first to comprehensively profile the gut virome of marmots in Qinghai Province, uncovering novel viral strains and highlighting how extreme environments drive viral diversity. Marmots, as key species in these regions, can act as bridges for virus transmission among wildlife, livestock, and humans, posing zoonotic risks. Understanding these viral communities is essential for predicting and preventing future outbreaks. Our findings emphasize the urgent need for integrated, One Health-based surveillance strategies to safeguard both public health and biodiversity in fragile high-altitude ecosystems.

Source: mSphere, https://journals.asm.org/doi/full/10.1128/msphere.00297-25?af=R

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Ten Previously Unassigned #Human #Cosavirus #Genotypes Detected in Feces of #Children with Non-Polio #AFP in #Nigeria in 2020

Abstract

Since its discovery via metagenomics in 2008, human cosavirus (HCoSV) has been detected in the cerebrospinal fluid (CSF) and feces of humans with meningitis, acute flaccid paralysis (AFP), and acute gastroenteritis. To date, 34 HCoSV genotypes have been documented by the Picornaviridae study group. However, the documented genetic diversity of HCoSV in Nigeria is limited. Here we describe the genetic diversity of HCoSV in Nigeria using a metagenomics approach. Archived and anonymized fecal specimens from children (under 15 years old) diagnosed with non-polio AFP from five states in Nigeria were analyzed. Virus-like particles were purified from 55 pools (made from 254 samples) using the NetoVIR protocol. Pools were subjected to nucleic acid extraction and metagenomic sequencing. Reads were trimmed and assembled, and contigs classified as HCoSV were subjected to phylogenetic, pairwise identity, recombination analysis, and, when necessary, immuno-informatics and capsid structure prediction. Fifteen pools yielded 23 genomes of HCoSV. Phylogenetic and pairwise identity analysis showed that all belonged to four species (eleven, three, three, and six members of Cosavirus asiani, Cosavirus bepakis, Cosavirus depakis, and Cosavirus eaustrali, respectively) and seventeen genotypes. Ten genomes belong to seven (HCoSV-A3/A10, A15, A17, A19, A24, D3, and E1) previously assigned genotypes, while the remaining thirteen genomes belonged to ten newly proposed genotypes across the four HCoSV species, based on the near-complete VP1 region (VP1*) of the cosavirus genome. Our analysis suggests the existence of at least seven and eight Cosavirus bepakis and Cosavirus eaustrali genotypes, respectively (including those described here). We report the first near-complete genomes of Cosavirus bepakis and Cosavirus depakis from Nigeria, which contributes to the increasing knowledge of the diversity of HCoSV, raising the number of tentative genotypes from 34 to over 40. Our findings suggest that the genetic diversity of HCoSV might be broader than is currently documented, highlighting the need for enhanced surveillance.

Source: Viruses, https://www.mdpi.com/1999-4915/17/6/844

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Phylogeographic Characterizations of Recent (2015–2023) #Senecavirus A Isolates from #Canada

Abstract

Senecavirus A (SVA) continues to cause vesicular lesions in swine in Canada and many regions worldwide. Since the vesicular lesions caused by SVA are similar to those caused by foot and mouth disease virus, swine vesicular disease virus and vesicular stomatitis virus, a foreign animal disease investigation must be initiated to rule out these diseases. SVA isolates from pigs displaying vesicular lesions in Canada from 2015 to 2023 were sequenced, and phylogeographic analysis was performed using the complete genome sequences. The results infer that SVA has spread between the United States and Canada several times. In addition, the results suggest that SVA spreads from different regions. SVA spread was inferred from Canada into Thailand, India and Mexico and inferred from the United States to Brazil, Columbia, Chile and China with ten separate introductions. Furthermore, recombination was observed in SVA genomes from Canada, the United States and China.

Source: Viruses, https://www.mdpi.com/1999-4915/17/2/141

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