Isolation and identification of Japanese encephalitis virus in Liaoning Province

<p><b>BACKGROUND</b>To study arboviruses carried by mosquitoes in Liaoning Province in 2002.</p><p><b>METHODS</b>Totally 4927 mosquitoes were collected from Liaoning Province in July 2002. Virus strains were isolated by inoculating BHK-21, C6/36 and Vero cells. The newly isolated strains were identified by serological (ELISA and IFA) and molecular methods (Real-Time PCR and RT-PCR).</p><p><b>RESULTS</b>Two strains were isolated from mosquitoes causing cytopathogenic effect (CPE) on cells and were fatal to suckling mice. Serological tests showed that both were positive for the antibody to JEV. The PrM and E gene were cloned and sequenced. The phylogenetic analysis showed that the new isolates belonged to genotype I, JEV. Sequence analysis showed that the homology of nucleotide sequences and amino acid (AA) sequences between the two strains was 100%. Compared with the nucleotide sequences between the two strains and the standard JEV vaccine strain SA14-14-2, the difference was up to 4.11%, and the difference of AA was 0.6%.</p><p><b>CONCLUSION</b>Two strains of JEV were isolated and identified in Liaoning province, both belonged to genotype I JEV.</p>