2001-2016年广州市登革3型病毒E基因序列及系统进化树分析

Molecular characterization and phylogenetic analysis of the envelope gene of dengue virus type 3 in Guangzhou,China,2001-2016

目的了解2001-2016年广州市登革3型病毒的流行情况,掌握毒株的进化情况和趋势。方法将登革热确诊病例的血清用荧光PCR检测,阳性血清用C6/36细胞进行病毒分离,测定分离毒株的E基因序列,与NCBI的毒株序列相比较,利用Mega 4.0软件构建系统进化树。结果 2001-2016年共分离到登革3型病毒24株,从基因型上分类属于基因亚型Ⅰ、Ⅱ、Ⅲ和Ⅴ型,基因亚型Ⅲ在流行年份和分离毒株数上稍占优势。流行病学调查和序列分析均显示与东南亚国家流行的登革热相关度较高。结论广州市登革3型病毒以输入为主,随着输入压力增大、基因亚型增多和转换,可能会使广州市登革热流行传播更为复杂,流行风险进一步增高。

We investigated the epidemiological characteristics of dengue virus serotype 3 in Guangzhou.By analyzing the E gene of the isolated strains,phylogenetic tree were constructed to know about the evolution and trend of the strains.Strains were isolated from the sera,which were detected positive by real-time PCR,of dengue fever patients using the C6/36 cell line.E gene of the isolated strains were sequenced and compared with the sequences in NCBI.Phylogenetic tree was drawn by Mega4.0.Twenty-four strains were isolated in 2001-2016.The strains clustered in genotype Ⅰ,Ⅱ,Ⅲ and Ⅴ.Genotype Ⅲ was predominate.The strains isolated in Guangzhou showed epidemiology connection and a high identity to the Southeast Asian strains.Dengue virus serotype 3 in Guangzhou is mainly imported.There are close connections between the Guangzhou strains and Southeast Asian strains.Guangzhou is in a high risk of imported dengue fever,and outbreak of dengue haemorrhagic fever and dengue shock syndrome.Increase of genotypes and shifts between genotypes may make the epidemic of DENV3 in Guangzhou more complex and raise the risk of outbreaks.