2008年甘肃省新分离乙脑病毒的分子生物学特征

目的 对2008年甘肃省新分离乙脑病毒的PrM和E基因区段进行序列测定和分析,明确新分离病毒的基因型别并对E基因序列的分子特征进行分析.方法 对新分离乙脑病毒的PrM和E基因区段进行PCR扩增并测定序列.使用ClustalX2.09、MegAlign和Mega4软件对核苷酸和氨基酸序列进行分析并绘制系统发生树.结果 系统进化分析结果显示6株病毒均为基因Ⅰ型乙脑病毒,并且与2001和2002年越南分离株、2004年日本分离株及2004年我国四川省分离株进化关系较近.新分离株与减毒活疫苗株SA14-14-2相比,E基因核苷酸同源性为87.5%～87.9%,氨基酸同源性为96.8%～97.2%.新分离株与疫苗株在E基因区段存在11处共同位点的氨基酸差异.结论 2008年甘肃省分离的乙脑病毒均为基因Ⅰ型乙脑病毒,新分离株E基因氨基酸序列与疫苗株相比有部分差异,但均不属于决定抗原性的关键位点.

Molecular characterization of Japanese Encephalitis Virus isolated from Gansu province in 2008

Objective To sequence PrM and E gene of the Japanese encephalitis virus isolated from Gansu province in 2008 and analysis the genotype of new JEV isolates and the molecular characterization of E gene. Methods Computer software was used to analyze nucleic acid sequence and deduced amino acid sequence, and draw phylogenetic trees, including ClustalX2.09, MegAlign and Mega4. Results The six JEV strains were clustered in genotype Ⅰ. 87.5%-87.9% identity in nucleotide sequence and 96.8%--97.2% identity in amino acid sequence were found in E gene when compared with the vaccine strain SA14-14-2. Eleven common amino acid differences were observed in E protein between new isolates and the vaccine strain. Conclusion Genotype Ⅰ JEVs were isolated from mosquitoes collected in Gansu province. The amino acid difference occurred in sites that were not the key ones affecting the antigenic of JEV.