两种基因型流行性乙型脑炎病毒在上海市共同流行

Co-prevalence of two genotypes of Japanese encephalitis virus in Shanghai,China

目的掌握上海市流行性乙型脑炎(乙脑)病毒基因型别特征。方法 2002-2005年在上海市奉贤县养猪场采集蚊虫标本,研磨处理后分离病毒,完成病毒细胞学、动物学、血清学及分子生物学鉴定。测定病毒全基因组序列,应用ATGC、ClustalX(1.83)、MegAlign、GeneDoc3.2和Mega5.0等生物学软件完成序列拼接、比对、核苷酸与氨基酸同源性分析、系统进化分析。结果共采集38347只蚊虫标本,主要是三带喙库蚊。分离到13株乙脑病毒。测定13株乙脑病毒全基因组序列,结合上海市其他年份分离的乙脑病毒及涵盖5个基因型别的其他乙脑病毒全基因组序列,通过系统进化分析发现,上海市2001、2003、2005和2007年分离的乙脑病毒属于基因Ⅰ型,2004年和2006年分离的乙脑病毒属于基因Ⅲ型。结论 2种基因型别乙脑病毒(Ⅰ、Ⅲ型)在上海市共同流行。

Objective To grasp the genotypic characteristics of Japanese encephalitis virus （JEV） in Shanghai, China. Methods Mosquito samples were collected from two pig farms in Fengxian county in Shanghai from 2002 to 2005. Viruses were isolated from ground samples and then identified by cytological, zoological, serological, and molecular biological methods. The whole genomes of viruses were sequenced. Sequence splicing, sequence alignment, nucleotide and amino acid homology analysis, and phylogenetic analysis were performed with biological sofiwares, such as ATGC, Clustal X （1.83）, MegAlign, GeneDoc 3.2, and Mega 5.0. Results A total of 38 347 mosquitoes were collected and the main species was Culex tritaeniorhynchus. Thirteen JEV strains were isolated and identified. The whole genomes of the 13 strains were sequenced. Phylogenetic analysis based on the whole genome sequences of other 5 genotypes of JEV and those JEV strains found in other years revealed that the JEV strains isolated in 2001, 2003, 2005, and 2007 belonged to genotype I and those isolated in 2004 and 2006 belonged to genotype III. Conclusion Two genotypes of JEV （ I and III） were co-prevalent in Shanghai, China.