Molecular characterization of mosquito-borne viruses strains newly isolated in Western Yunnan Province along the border of China and Myanmar, China

Abstract

Objective To analysis the molecular characterization of mosquito-borne viruses strains newly isolated in Western Yunnan Province along the border of China and Myanmar,China.Methods Mosquito samples was carried out with mosquito traps from Mangshi and Ruili counties of Dehong prefecture,Yunnan Province,once every month from Jan to Dec,2010.Mosquitoes were BHK-21 and C6/36 cells cul ture for viral isolation,and positive isolates were identified using RT-PCR and sequence analysis.Results A total of 69,209 mosquitoes comprised of 42 species representing seven genera were collected.Thirteen strains of Japanese encephalitis virus (JEV),four strains of Getah virus (GETV),one strain of Tibet orbivirus (TIBOV),seven strains of Culex pipiens pallens densovirus (CppDNV) were isolated from the mosquito pools.Phylogenetic analysis of E gene strowed that all the 13 JEV strains belonged to genotype I,and were closely related to isolates from other area of Yunnan Province and neighboring Chinese provinces,the most critical sites associated with viral virulence and antigenicity were conserved.The E2 gene of the four GETV strains shared high homology and closely relative with sequences of other GETVs from Yunnan Province.The VP1 gene of the newly-isolated Orbivirus shared closely related with sequeuces of TIBOV from Tibet Province,China,however,distinct difference with sequences of Yunnan orbivirus isolated from Yunnan Province.The NS1 gene of the seven CppDNV strains shared high homology and closdy relative with sequences of other CppDNVs from Yunnan Province and other provinces of China.Conclusion Genotype Ⅰ JEV,GETV,TIBOV and CppDNV were the first report in this area,suggested that these virus strains harbored relatively stable genetic characteristics and distinct regional features. Key words: Arbovirus;  Janpanese encephalitis virus;  Getah virus;  Tibet orbivirus;  Culex pipiens pallens densovirus;  Molecular characterization