Identification and genetic characterization of Xiabuqu River virus: A novel member of the Iflaviridae family detected in soft ticks from Tibet, China

Soft ticks, an important group of blood-sucking arthropods in nature, are widely distributed globally and can carry a wide range of pathogens, including Theileria ovis, Anaplasma ovis, Rickettsia spp. and African swine fever virus. In this study, we identified a novel single positive-stranded RNA virus, tentatively named Xiabuqu River virus (XRV), for the first time from soft ticks collected in Shigatse, Tibet. A total of 96 engorged soft ticks were collected from Tibetan sheep, with each tick assigned to a separate pool for analysis. The complete coding sequence of XRV was determined through next-generation sequencing, revealing a sequence length of 9277 nucleotides that includes a single open reading frame (ORF) encoding proteins such as the capsid protein, RNA helicase, and RNA-dependent RNA polymerase (RDRP). Quantitative RT-PCR and nested PCR were utilized to investigate the distribution of XRV within the tick sample. Pairwise distance analysis revealed that all obtained viral sequences shared a high nucleotide identity. Phylogenetic analysis demonstrated that XRV clustered with Lhasa Iflav tick virus 1, Fuyun tick virus 2, and Hubei tick virus 2. Further analyses indicated that XRV is a new member of the unclassified genus Iflavirus within the family Iflaviridae.