title: Molecular epidemiological analyses of Japanese encephalitis virus isolates from swine in Japan from 2002 to 2004.
abstract: To characterize Japanese encephalitis virus (JEV) strains recently prevalent in Japan, JEV surveillance was performed in pigs from 2002 to 2004. Eleven new JEV isolates were obtained and compared with previous isolates from Japan and other Asian countries. All of the isolates were classified into genotype 1 by nucleotide sequence analysis of the E gene. Two new isolates with different levels of neurovirulence and neuroinvasiveness, but with only one nucleotide difference in the E gene, Sw/Mie/34/2004 and Sw/Mie/40/2004, were isolated at the same farm on the same day. Sw/Mie/40/2004 displayed higher neurovirulence and neuroinvasiveness in mice than the other four new isolates. Another new isolate, Sw/Hiroshima/25/2002, was neutralized by antiserum to Beijing-1 at a level similar to the homologous Beijing-1 strain, whilst seven other new isolates were neutralized at 10-fold-lower titres. However, there were no amino acid differences in the E protein among these eight isolates. The present study indicated that the 11 new JEV isolates were genetically similar, but biologically and serologically heterogeneous.
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Nerome
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Takasaki
authors.affiliation: Mitsubishi Kagaku Bio-Clinical Laboratories Inc., Tokyo, Japan.|Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kotaki
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Chang-Kweng
authors.initials: CK
authors.lastname: Lim
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Ito
authors.affiliation: Mie Prefectural Institute of Public Health and Environmental Sciences, Mie, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sugiyama
authors.affiliation: Mie Prefectural Institute of Public Health and Environmental Sciences, Mie, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Yamauchi
authors.affiliation: Mie Prefectural Institute of Public Health and Environmental Sciences, Mie, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Yano
authors.affiliation: Kagawa Prefectural Institute of Environment and Health, Kagawa, Japan.
authors.forename: Taeko
authors.initials: T
authors.lastname: Kameyama
authors.affiliation: Kagawa Prefectural Institute of Environment and Health, Kagawa, Japan.
authors.forename: Ichiko
authors.initials: I
authors.lastname: Morishita
authors.affiliation: Hiroshima Prefectural Institute of Health and Environment, Hiroshima, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Kuwayama
authors.affiliation: Chiba Prefectural Institute of Public Health, Chiba, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ogawa
authors.affiliation: Shizuoka Prefectural Institute of Environment and Hygiene, Shizuoka, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Sahara
authors.affiliation: Shizuoka Prefectural Seibu Meat Inspection Center, Shizuoka, Japan.
authors.forename: Asaka
authors.initials: A
authors.lastname: Ikegaya
authors.affiliation: Shizuoka Prefectural Seibu Meat Inspection Center, Shizuoka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kanda
authors.affiliation: Shizuoka Prefectural Seibu Meat Inspection Center, Shizuoka, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hosoya
authors.affiliation: Okinawa Prefectural Institute of Health and Environment, Okinawa, Japan.
authors.forename: Kiyomasa
authors.initials: K
authors.lastname: Itokazu
authors.affiliation: Ishikawa Prefectural Institute of Public Health and Environmental Science, Ishikawa, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Onishi
authors.affiliation: The Public Health Institute of Kochi Prefecture, Kochi, Japan.
authors.forename: Seizou
authors.initials: S
authors.lastname: Chiya
authors.affiliation: Tokyo Metropolitan Institute of Public Health, Tokyo, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Yoshida
authors.affiliation: Tokyo Metropolitan Institute of Public Health, Tokyo, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Tabei
authors.affiliation: Kumamoto Prefectural Institute of Public Health and Environmental Science, Kumamoto, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Katsuki
authors.affiliation: Kumamoto Prefectural Institute of Public Health and Environmental Science, Kumamoto, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Tabata
authors.affiliation: Kumamoto Prefectural Institute of Public Health and Environmental Science, Kumamoto, Japan.
authors.forename: Seiya
authors.initials: S
authors.lastname: Harada
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases (NIID), Toyama, Shinjuku, Tokyo 162-8640, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kurane
mesh_terms: D000818:Animals; D001181:Arthropods / Q000821:virology; D001208:Asia / Q000453:epidemiology; D004664:Encephalitis Virus, Japanese / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D004672:Encephalitis, Japanese / Q000453:epidemiology* / Q000635:transmission / Q000662:veterinary*; D007564:Japan / Q000453:epidemiology; D008969:Molecular Sequence Data; D013552:Swine / Q000821:virology*; D013553:Swine Diseases / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D014774:Virulence