河南省唐河县分离到基因1型乙型脑炎病毒

目的 从河南省唐河县采集的蚊虫标本中分离乙型脑炎病毒(JEV)并确定其基因分型及E基因区段氨基酸序列特征.方法对2004年采集蚊虫标本进行病毒分离,对新分离的乙脑病毒进行生物学、血清学及分子生物学鉴定.逆转录聚合酶链反应(RT-PCR)扩增新分离JEV的PrM、E区段核苷酸序列,测序后应用Clustal X软件做碱基配对分析,MEGA3.1完成病毒进化分析,GENEDOS(3.2)软件完成氨基酸位点分析.结果共采集3722只蚊虫标本,包括:库蚊、骚扰阿蚊、伊蚊及按蚊.从库蚊标本中分离到3株属于基因1型的乙脑病毒,E区段核苷酸和氨基酸与减毒活疫苗株SA14-14-2株的同源性分别为86.9%～87.7%,氨基酸同源性为95.2%～97.0%,存在12处共同的氨基酸位点差异.结论从河南省唐河县首次分离到基因1型的乙脑病毒.E基因与疫苗株相比有部分氨基酸差异,但现行疫苗株理论上可以保护新分离乙脑病毒.

Isolation and identification of Japanese encephalitis virus in Tanghe county, Henan Province

OBJECTIVE: To isolate Japanese encephalitis virus (JEV) from mosquitoes collected in Tanghe County, Henan province and analyze the genotype of the newly isolated JEV strains and the characteristics of amino acid in the E gene. METHODS: Viruses were isolated from mosquitoes collected in 2004 and identified by biological, serological and molecular biologic methods. PrM and E segments of the newly isolated JEV were amplified by RT-PCR, the PCR products were purified and sequenced. Multiple alignment, phylogenetic and amino acid (AA) analysis were carried out by Clustal X (1.8) program, MEGA 3.1 and GENEDOS (3.2). RESULTS: Totally 3722 mosquitoes were collected including Culex, Armigeres, Aedes, Anopheline. Three new JEV strains isolated from Culex belonged to genotype 1. The homologue of nucleotide and amino acid of E gene between new JEV strains and live attenuated vaccine strain SA14-14-2 was 86.9-87.7% and 95.2%-97.0%, respectively. Totally there were 12 common sites of amino acid differences in E gene between them. CONCLUSION: Newly isolated viruses in Henan province belonged to JEV genotype 1. It suggests that the vaccine strain SA14-14-2 currently used for preventing JE is able to protect people from JEV infection, although there are some amino acid differences between them.