Two Rhabdoviruses, One Novel, Isolated from Armigeres subalbatus in China

Abstract

The family Rhabdoviridae contain important human and mammalian pathogens that are vectored by different arthropod species. The ground supernatants of mosquitoes were used to inoculate in BHK-21 and C6/36 cells for virus isolation. Then, the viral complete genome sequence was obtained and used for phylogenetic analysis. In this study, we observed a cytopathic effect (CPE) in mosquito cells (C6/36) and rod-like virion after inoculating a pool of Armigeres subalbatus samples collected in Shanxi Province, China, in 2019 (SX1916). Meta-transcriptomics sequencing revealed the presence of two distinctive rhabdoviruses with similar abundance levels, namely, Shanxi Armigeres subalbatus rhabdovirus (SXARV) and Shanxi Arboretum virus (SXABTV). Despite the fact that the SXARV genome (9590 nt) was much shorter than that of SXABTV (11,480 nt), both belonged to the Almendravirus group within Rhabdoviridae whose genomes encoded five proteins (N, P, M, G, and L) and a small hydrophobin (U1) and the difference in lengths is mainly caused by a substantially shorter N protein encoded by SXARV. On the phylogenetic tree, SXABTV was closely related (90.7% amino acid identity at L protein) with the Arboretum virus isolated from Psorophora albigenu mosquitoes in Peru in 2014, whereas SXARV was distantly related to Rio Chico virus (63.3% amino acid identity), a genetic distance large enough to be defined as a new species within Rhabdoviridae. Collectively, we report a simultaneous isolation of two related rhabdoviruses from Armigeres subalbatus that marked the circulation of almendraviruses in Shanxi, China.