Phylogenetic and virulence analysis of tick-borne encephalitis viruses from Japan and far-Eastern Russia.
We have previously reported that tick-borne encephalitis (TBE) is endemic in a specific area of Hokkaido, Japan. In Oshima, the southern part of Hokkaido, TBE virus was isolated from sentinel dogs, ticks and rodents in 1995 and 1996. To identify when these TBE viruses emerged in Hokkaido, the times of divergence of TBE virus strains isolated in Oshima and far-eastern Russia were estimated. TBE virus was isolated in Khabarovsk in 1998 and the nucleotide sequences of viral envelope protein genes of isolates from Oshima and Khabarovsk were compared. From the synonymous substitution rate of these virus strains, the lineage divergence time of these TBE virus strains was predicted phylogenetically to be about 260-430 years ago. Furthermore, the virulence of TBE virus isolates from Oshima and Khabarovsk were compared in a mouse model. The results showed that the isolates possessed very similar virulence in mice. This report provides evidence that the Oshima strains of TBE virus in Hokkaido emerged from far-eastern Russia a few hundred years ago and this explains why these strains possess virulence similar to the TBE viruses isolated in Russia.
Hayasaka
Daisuke
D
Laboratory of Public Health, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan1.
Suzuki
Yoshiyuki
Y
Center for Information Biology, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka-ken 411-8540, Japan2.
Kariwa
Hiroaki
H
Laboratory of Public Health, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan1.
Ivanov
Leonid
L
Plague Control Station of Khabarovsk, Khabarovsk 680311, Russia3.
Volkov
Vladimir
V
Plague Control Station of Khabarovsk, Khabarovsk 680311, Russia3.
Demenev
Vladimir
V
Public Health Interregional Association of Economic Interaction in Far East and Transbaical Area, Khabarovsk 680002, Russia4.
Mizutani
Tetsuya
T
Laboratory of Public Health, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan1.
Gojobori
Takashi
T
Center for Information Biology, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka-ken 411-8540, Japan2.
Takashima
Ikuo
I
Laboratory of Public Health, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan1.
D000595:Amino Acid Sequence; D000818:Animals; D004283:Dog Diseases / Q000821:virology; D004285:Dogs; D004669:Encephalitis Viruses, Tick-Borne / Q000235:genetics* / Q000472:pathogenicity*; D004675:Encephalitis, Tick-Borne / Q000662:veterinary / Q000821:virology*; D006801:Humans; D007564:Japan; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D012426:Russia; D013987:Ticks / Q000821:virology; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics; D014774:Virulence
D014759:Viral Envelope Proteins; C065696:glycoprotein E, Flavivirus