Genotype I of Japanese encephalitis virus as the dominant genotype among mosquitoes in Shandong

Abstract

Objective To analysis the genotype of Japanese encephalitis virus (JEV) in mosquitoes from Shandong province. Methods Mosquitoes were collected between August and September in Weishan county, Junan county, and Kenli county of Shandong province in 2016. Viruses were isolated by BHK-21 cell and identified by molecular method . Real-Time RT-PCR was conducted to detect the Japanese encephalitis virus carried by the mosquitoes. Results A total of 8418 mosquitoes divided into 81 pools including 3 species, Culex tritaeniorhynchus, Anopheles sinensis and Armigeres obturbans. Eight Japanese encephalitis viruses were isolated; 23 pools were positive by JEV specific real-time RT-PCR. Phylogenetic analysis on E sequence of JEV showed all JEV strains belonged to genotype Ⅰ JEV, and new strains that were homogenous with previous JEV strains isolated from Shandong. Conclusions Genotype Ⅰ JEV was the dominant genotype in Shandong province. Key words: Japanese encephalitis virus; Phylogenetic analysis; Virus isolation