First Isolation and Characterization of Liao Ning Virus from Aedes Vexans Mosquitoes in Hokkaido, Japan, in 2022.

Abstract

Background: The Liao ning virus (LNV), belonging to the genus Seadornavirus within the family Sedoreoviridae, is a mosquito-borne virus. It was originally isolated from Aedes dorsalis mosquitoes in China. The original LNV strain, LNVS-NE97-31, was reported to infect several mammalian cell lines and cause hemorrhagic symptoms in mice. Subsequently, another LNV strain, LNV NSW B115745, was isolated from Australian mosquitoes; it was reported to exhibit insect-specific infection. Materials and Methods: Virus isolation was performed on mosquitoes collected in northern Hokkaido, Japan, in 2022. The isolated virus was subjected to genomic and growth kinetics analyses. Results: A LNV strain was isolated from Aedes vexans mosquitoes. Genomic sequencing and phylogenetic analysis revealed the new strain as 22WN03, and it formed a robust clade with the original Chinese strain, LNVS-NE97-31. Growth kinetics analysis did not reveal any mammalian or avian cell line susceptible to infection by the strain 22WN03. Conclusion: Overall, the results suggested that the strain 22WN03 has insect-specific infection characteristics, similar to as the Australian strain. Taken together, our findings could expand our knowledge of not only the diversity and geographical distribution of seadornaviruses in Asia but also the ecology of LNV.