中山市2007—2014年1型登革病毒E基因分子特征分析

Molecular Characteristics of E Gene of Dengue Type 1 Viruses Isolated from 2007 to 2014 in Zhongshan City

目的分离、鉴定中山市2007—2014年1型登革病毒并获得E基因序列,从分子水平分析其系统进化和地域来源情况,了解该病毒各年份的流行性质。方法收集中山市2007—2014年登革热患者急性期血清,接种C6/36细胞分离登革病毒,应用RT-PCR技术扩增病毒的包膜蛋白E基因全长,并对序列进行系统进化和同源性分析。结果共分离到登革1型病毒流行株25株,参考国际标准株E基因序列将其分为GⅠ型和GⅤ型2个基因型。其中2007年3株,2012年3株,2013年3株,2014年7株聚集在GⅠ型中,2014年9株聚集在GⅤ型中。中山2014年登革病毒GⅠ型流行株与中山市2007年、2012年、2013年流行株E基因核苷酸(氨基酸)序列相似度分别为98.25%(99.40%)、98.18%(99.80%)、99.73%(100.00%),与珠三角2014年广州、珠海输入中山株的氨基酸序列相似度为100.00%;中山市2013年登革病毒GⅠ型流行株与广州、佛山的2013年流行株E基因核苷酸(氨基酸)序列相似度分别为99.67%(100.00%)、99.74%(100.00%)。结论 2007—2014年中山市流行的登革1型病毒有2个基因型(GⅠ型和GⅤ型)。2014年GⅤ型可能由国外输入,GⅠ型中2007年和2012年为国外输入株,2013年及2014年流行株E基因序列相似度高,2014年的登革流行可能与2013年流行株本地化有关。

Objective To obtain the E gene sequences of dengue type 1viruses isolated from2007 to 2014in Zhongshan city,and to analyze their phyletic evolution,geographic origin and epidemical features.Methods Dengue viruses were isolated in C6/36 cells from the acute phase serum of patients with dengue fever from 2007 to 2014.The envelope protein E gene was amplified by RT-PCR,and the homology and phylogeny were analyzed by sequencing.Results A total of 25 dengue type 1virus strains were isolated,which were identified as two genotypes:GⅠand GⅤ.Among the 25 strains,16were clustered in genotype GⅠ(3isolated in 2007,3in 2012,3in 2013,and 7in 2014),and 9in genotype GⅤ(isolated in 2014).The nucleotide(amino acid)sequence similarities of dengue virus strains isolated in 2014 to those isolated in 2007,2012 and 2013were98.25%(99.40%),98.18%(99.80%)and 99.73%(100.00%)in Zhongshan,respectively.Furthermore,the amino acid sequence similarities of dengue virus strains isolated in Zhongshan to those imported from Guangzhou and Zhuhai were both 100.00%in 2014.The nucleotide(amino acid)sequence similarities of dengue virus strains isolated in Zhongshan to those isolated from Guangzhou and Foshan were 99.67%(100.00%)and 99.74%(100.00%)in 2013,respectively.Conclusion Dengue type 1viruses isolated from Zhongshan between 2007 and 2014were identified as two genotypes.Among them,genotype GⅤstrains might be imported from abroad,and genotype GⅠstrains isolated in 2007 and 2012were foreign strains.The E gene sequences of dengue type 1viruses showed a high similarity between strains isolated in 2013 and strains isolated in2014,suggesting that dengue epidemic in 2014 may be correlated with strain localization in 2013.