title: Molecular characterization of a novel hepatitis E virus (HEV) strain obtained from a wild boar in Japan that is highly divergent from the previously recognized HEV strains.
abstract: Although a consensus classification system for hepatitis E virus (HEV) genotypes is currently unavailable, HEV variants (JBOAR135-Shiz09 and wbJOY_06) from wild boars (Sus scrofa leucomystax) have provisionally been classified into two novel genotypes (5 and 6). While performing a survey of HEV infections among 566 wild boars that were captured in Japan between January 2010 and August 2013, we found 24 boars (4.2%) with ongoing HEV infections: 13 had genotype 3 HEV, 10 had genotype 4 HEV and the remaining boar possessed a novel HEV variant (designated wbJNN_13). The entire wbJNN_13 genome comprised 7247 nucleotides excluding the poly(A) tail, and was highly divergent from known genotype 1 to 4 HEV isolates derived from humans, swine, wild boars, deer, mongoose and rabbits by 22.4-28.2%, JBOAR135-Shiz09 and wbJOY_06 by 19.6-21.9% and rat, ferret, bat and avian HEV isolates by 40.9-46.1% over the entire genome. Phylogenetic trees confirmed that wbJNN_13 is distantly related to all known HEV isolates. A Simplot analysis revealed no significant recombination among the existing HEV strains. These results indicate the presence of at least three genetic lineages of presumably boar-indigenous HEV strains. Further studies to fully understand the extent of the genomic heterogeneity of HEV variants infecting wild boars are warranted.
authors.affiliation: Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishizawa
authors.affiliation: Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nagashima
authors.affiliation: Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan.
authors.forename: Suljid
authors.initials: S
authors.lastname: Jirintai
authors.affiliation: Hepatology Research Center, Okayama Saiseikai General Hospital, Okayama-shi, Okayama 700-8511, Japan.
authors.forename: Manri
authors.initials: M
authors.lastname: Kawakami
authors.affiliation: Nara Municipal Tahara Clinic, Nara-shi, Nara 630-2174, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Sonoda
authors.affiliation: Tessei-cho Clinic, Niimi-shi, Okayama 719-3701, Japan.
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki-shi, Miyazaki 889-2155, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Yamamoto
authors.affiliation: Osaba Family Clinic, Yamaguchi-shi, Yamaguchi 753-0212, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shigemoto
authors.affiliation: Division of Internal Medicine, Okayama University Hospital Misasa Medical Center, Misasa, Tottori 682-0122, Japan.
authors.forename: Kozo
authors.initials: K
authors.lastname: Ashida
authors.affiliation: Kamiichi General Hospital, Kamiichi, Toyama 930-0391, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan. Electronic address: hokamoto@jichi.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D016679:Genome, Viral; D005838:Genotype; D016751:Hepatitis E / Q000662:veterinary* / Q000821:virology; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D034421:Sus scrofa / Q000821:virology*; D013552:Swine; D013553:Swine Diseases / Q000821:virology*
chemical_list: D012367:RNA, Viral
keywords: Genotype; Hepatitis E virus; Phylogeny; Wild boar