title: Genetic and antigenic characterization of bovine viral diarrhea viruses isolated from cattle in Hokkaido, Japan.
abstract: In our previous study, we genetically analyzed bovine viral diarrhea viruses (BVDVs) isolated from 2000 to 2006 in Japan and reported that subgenotype 1b viruses were predominant. In the present study, 766 BVDVs isolated from 2006 to 2014 in Hokkaido, Japan, were genetically analyzed to understand recent epidemics. Phylogenetic analysis based on nucleotide sequences of the 5'-untranslated region of viral genome revealed that 766 isolates were classified as genotype 1 (BVDV-1; 544 isolates) and genotype 2 (BVDV-2; 222). BVDV-1 isolates were further divided into BVDV-1a (93), 1b (371) and 1c (80) subgenotypes, and all BVDV-2 isolates were grouped into BVDV-2a subgenotype (222). Further comparative analysis was performed with BVDV-1a, 1b and 2a viruses isolated from 2001 to 2014. Phylogenetic analysis based on nucleotide sequences of the viral glycoprotein E2 gene, a major target of neutralizing antibodies, revealed that BVDV-1a, 1b and 2a isolates were further classified into several clusters. Cross-neutralization tests showed that BVDV-1b isolates were antigenically different from BVDV-1a isolates, and almost BVDV-1a, 1b and 2a isolates were antigenically similar among each subgenotype and each E2 cluster. Taken together, BVDV-1b viruses are still predominant, and BVDV-2a viruses have increased recently in Hokkaido, Japan. Field isolates of BVDV-1a, 1b and 2a show genetic diversity on the E2 gene with antigenic conservation among each subgenotype during the last 14 years.
authors.affiliation: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Abe
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Tamura
authors.forename: Shiho
authors.initials: S
authors.lastname: Torii
authors.forename: Shiho
authors.initials: S
authors.lastname: Wakamori
authors.forename: Makoto
authors.initials: M
authors.lastname: Nagai
authors.forename: Kazuya
authors.initials: K
authors.lastname: Mitsuhashi
authors.forename: Junki
authors.initials: J
authors.lastname: Mine
authors.forename: Yuri
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Naofumi
authors.initials: N
authors.lastname: Nagashima
authors.forename: Fumi
authors.initials: F
authors.lastname: Yoshino
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Sugita
authors.forename: Takushi
authors.initials: T
authors.lastname: Nomura
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Okamatsu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kida
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakoda
mesh_terms: D000818:Animals; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000276:immunology / Q000821:virology*; D002417:Cattle / Q000821:virology; D001908:Diarrhea Viruses, Bovine Viral / Q000235:genetics* / Q000276:immunology; D016679:Genome, Viral / Q000235:genetics; D005838:Genotype; D007564:Japan / Q000453:epidemiology; D009500:Neutralization Tests / Q000662:veterinary; D010802:Phylogeny