Isolation and identification of arboviruses in Liaoning province, 2009

Objective To investigate the distribution of arboviruses in part of Liaoning province. Methods Mosquitoes were collected from Chaoyang, Anshan, Jinzhou and Huludao cities in Liaoning province in 2009. The mosquitoes were divided into pools and the homogenates were inoculated onto C6/36 and BHK-21cells.The new isolates were identified by antigenic test and molecular biological methods. The sequences were analyzed by bioinformatics. Results Totally 3600 mosquitoes were collected from the 4 cities, including Anopheles sinensis (47.2%), Culex pipiens pallens (26.4%), Aedes vexans (18.1%) and Culex tritaeniorhynchus (6.9%). The isolates produced CPE on BHK-21 cell line. Two isolate (LN0905 and LN0923) were identified as Japanese encephalitis virus (JEV). Phylogenetic analysis showed that the 2 JEV stains were clustered into genotype Ⅰ. Conclusion Genotype Ⅰ JEV was isolated from the mosquitoes collected in Aanshan and Chaoyang in Liaoning province. The sequence of the new isolates had close phylogenetic relationship with JEV strains isolated in Shanghai in 2001.