title: Molecular characterization of a novel orthomyxovirus from rainbow and steelhead trout (Oncorhynchus mykiss).
abstract: A novel virus, rainbow trout orthomyxovirus (RbtOV), was isolated in 1997 and again in 2000 from commercially-reared rainbow trout (Oncorhynchus mykiss) in Idaho, USA. The virus grew optimally in the CHSE-214 cell line at 15°C producing a diffuse cytopathic effect; however, juvenile rainbow trout exposed to cell culture-grown virus showed no mortality or gross pathology. Electron microscopy of preparations from infected cell cultures revealed the presence of typical orthomyxovirus particles. The complete genome of RbtOV is comprised of eight linear segments of single-stranded, negative-sense RNA having highly conserved 5' and 3'-terminal nucleotide sequences. Another virus isolated in 2014 from steelhead trout (also O. mykiss) in Wisconsin, USA, and designated SttOV was found to have eight genome segments with high amino acid sequence identities (89-99%) to the corresponding genes of RbtOV, suggesting these new viruses are isolates of the same virus species and may be more widespread than currently realized. The new isolates had the same genome segment order and the closest pairwise amino acid sequence identities of 16-42% with Infectious salmon anemia virus (ISAV), the type species and currently only member of the genus Isavirus in the family Orthomyxoviridae. However, pairwise comparisons of the predicted amino acid sequences of the 10 RbtOV and SttOV proteins with orthologs from representatives of the established orthomyxoviral genera and a phylogenetic analysis using the PB1 protein showed that while RbtOV and SttOV clustered most closely with ISAV, they diverged sufficiently to merit consideration as representatives of a novel genus. A set of PCR primers was designed using conserved regions of the PB1 gene to produce amplicons that may be sequenced for identification of similar fish orthomyxoviruses in the future.
authors.affiliation: U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA 98115, USA. Electronic address: bbatts@usgs.gov.
authors.forename: William N
authors.initials: WN
authors.lastname: Batts
authors.affiliation: Research Division, Clear Springs Foods, Inc., Buhl, ID 83316, USA.
authors.forename: Scott E
authors.initials: SE
authors.lastname: LaPatra
authors.affiliation: U.S. Fish and Wildlife Service, La Crosse Fish Health Center, Onalaska, WI 54650, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Katona
authors.affiliation: U.S. Fish and Wildlife Service, La Crosse Fish Health Center, Onalaska, WI 54650, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Leis
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30329, USA.
authors.forename: Terry Fei Fan
authors.initials: TFF
authors.lastname: Ng
authors.affiliation: School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98105, USA.
authors.forename: Marine S O
authors.initials: MSO
authors.lastname: Brieuc
authors.affiliation: School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98105, USA.
authors.forename: Rachel B
authors.initials: RB
authors.lastname: Breyta
authors.affiliation: U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA 98115, USA.
authors.forename: Maureen K
authors.initials: MK
authors.lastname: Purcell
authors.affiliation: U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA 98115, USA.
authors.forename: Carla M
authors.initials: CM
authors.lastname: Conway
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Waltzek
authors.affiliation: Blood Systems Research Institute, San Francisco, CA 94118, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Delwart
authors.affiliation: U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA 98115, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Winton
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005393:Fish Diseases / Q000821:virology*; D049810:Genetic Speciation; D016679:Genome, Viral; D046829:Isavirus / Q000145:classification / Q000235:genetics; D017686:Oncorhynchus mykiss / Q000821:virology*; D009975:Orthomyxoviridae / Q000145:classification / Q000235:genetics*; D009976:Orthomyxoviridae Infections / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D012367:RNA, Viral
keywords: Fish virus; Oncorhynchus mykiss; Orthomyxovirus; Rainbow trout