Virome Profiling Of Rodents In Xinjiang,China:Isolation And Characterization Of A New Wenzhou Mammarenavirus Variant

Rodents(order Rodentia),as the most diverse and widest distributed mammals,are a natural reservoir of many zoonotic viruses.However,little is known about the viral diversity harbored by rodents in China.The Xinjiang Uygur autonomous region,located in northwestern China,provides an important terrestrial corridor of the Silk Road connecting China and central Asia and Europe.This vast region,with a temperate continental climate,consists mostly of desert and grassland,the latter supporting well developed animal husbandry and agricultural industries as well as an ecosystem of 86 known rodent species.Consequently,viruses carried by rodents in this vast region have been poorly investigated,although they potentially pose a major risk to public health,particularly to agricultural workers in direct or indirect contact with infected animals.Here we performed viral metagenomic analyses of 314 wild rodents covering 7 species,sampled in northwest China,with results revealing 7,067 reads(0.14%)being annotated to viruses of 24 families including some potentially pathogenic to humans and other animals such as arenaviruses,paramyxoviruses,dicistroviruses,parvoviruses and bunyaviruses.The virus-like reads of mammal-or arthropod-infecting were selected and assembled into contigs and subsequently employed for phylogenetic analyses.We further conducted a systematic virological characterization of a novel mammarenavirus,QARn1,identified after isolation from a brown rat(Rattus norvegicus).Full genomic and phylogenetic analyses showed that QARn1 was a variant of Wenzhou mammarenavirus(WENV)and formed a new branch within the WENV clade.Experimental infection of Sprague-Dawley rats with QARn1 did not present overt pathology,but specific humoral immune responses developed,and mild hemorrhage and immunocyte infiltration of the lungs and thymus were observed.These observations have expanded the geographic distribution of WENV to Central Asia,and have suggested that R.norvegicus rats are natural hosts of this virus,although its public threat to humans and other animals requires further investigation.This study provided the basic data for the Patho-ecology studies about the rodent-borne viruses in Xinjiang.