Isolation and identification of Japanese encephalitis virus XJ/08/01 strain and phylognetic analysis of its PrM/E gene.

In 2008,150 pig brain samples were collected from a pig farm in Shihezi Prefecture of Xinjiang Uygur Autonomous Region,China.Nucleic acid of NS1 gene of Japanese encephalitis virus(JEV) was detected by RT-PCR from the samples,and 32 out of them were positive.Suckling mice were inoculated with lapping liquids from the 32 positive samples,and one strain of JEV,XJ/08/01,was isolated successfully after 3 passages in the suckling mice.Then primers were designed to amplify JEV PrM/E gene from the brain samples of the inoculated suckling mice.Sequence analysis based on the amplified PrM/E gene indicated that XJ/08/01 shared 99.6% homology with that of JEV vaccine strain SA14-14-2.Genotyping results showed that the isolated XJ/08/01 represented JEV genotypeⅢ.