Isolation and identification of Japanese encephalitis virus in Guangxi, 2005

Objective To isolate and identify Japanese encephalitis virus from mosquitoes collected in Guangxi, 2005. Methods Mosquito samples were collected in Beiliu and Jingxi, Guangxi autonomous region. Japanese encephalitis virus was isolated by incubating C6/36 and BHK21 cells with mosquito homogenizations. RT-PCR was used to identify the isolates. E genes of the virus were sequenced and genotype of the virus was analyzed by bioinformatics software. Results A total of 1,196 mosquitoes (771 Culex tritaeniorhynchus and 425 Armigeres subalbatus) were collected and processed for virus isolation. 3 strains of genotype 1 Japanese encephalitis virus were obtained from Culex tritaeniorhynchus. E gene nucleic acid and amino acid homology of the 3 isolates was up to 99.3% and 99.8% respectively. The homology of 3 isolates and E gene nucleic acid and amino acid of Vietnam Japanese encephalitis strains was up to 98.4% and 99.6% respectively. Conclusion 3 strains of Japanese encephalitis virus were isolated from mosquitoes collected in Guangxi. This was the first report of isolation of genotype 1 Japanese encephalitis virus in Guangxi.