title: First isolation and characterization of a mosquito-borne orbivirus belonging to the species Umatilla virus in East Asia.
abstract: An orbivirus was isolated from a sample from the ornithophilic mosquito Culex sasai in Japan. The virus, designated Koyama Hill virus (KHV), replicated to high titer in a mosquito cell line and to a low titer in an avian cell line, but the release of progeny viruses was not observed in mammalian cell lines inoculated with KHV. Electron microscopic examination of KHV-infected mosquito cells showed approximately 70-nm virus particles and viral tubules typical of members of the genus Orbivirus, family Reoviridae. KHV efficiently replicated in Cx. sasai mosquitoes, suggesting a potential vector species for KHV transmission in nature. Full-length viral genome sequencing and phylogenetic analysis revealed that KHV is closely related to Umatilla virus (UMAV) and Stretch Lagoon orbivirus (SLOV). This suggests that KHV is a new member of the species Umatilla virus, an orbivirus species not previously observed in East Asia. The KHV genome segment encoding NS1 contains a notable sequence deletion and heterogeneity compared with a prototype UMAV, which may affect its growth properties and pathogenicity in host cells. These results provide new insights into the genetic diversity and geographic distribution of members of the species Umatilla virus.
authors.affiliation: Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ejiri
authors.forename: Ryusei
authors.initials: R
authors.lastname: Kuwata
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tsuda
authors.forename: Toshinori
authors.initials: T
authors.lastname: Sasaki
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Yukita
authors.initials: Y
authors.lastname: Sato
authors.forename: Kyoko
authors.initials: K
authors.lastname: Sawabe
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Isawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003465:Culex / Q000821:virology; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D018163:Orbivirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D012088:Reoviridae Infections; D017422:Sequence Analysis, DNA; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D014779:Virus Replication / Q000502:physiology
chemical_list: D012367:RNA, Viral; D017361:Viral Nonstructural Proteins