南京市2007-2013年H3N2流感HA分子进化特征分析

目的 分析2007—2013年南京市H3N2亚型流感HA基因分子学特征。方法 选择2007—2013年59株H3N2亚型流感分离株,自行设计HA片段引物扩增分离毒株HA片段并测序, 利用DNAStar、MEGA等软件对HA分子学特征进行分析;结果 发病时间存在明显的季节性;进化树分析2007—2013年分离株按年代分成3个分支;分离株较疫苗株及不同年份之间,发生多个抗原位点及受体结合位点氨基酸的替换;2007—2013年,我市H3N2亚型流感流行情况出现两次波动,可能同基因的突变、重组有关。结论 抗原位点及受体结合位点氨基酸的突变,对流感的防控及疫苗的保护效果产生极大的挑战。

Molecular evolution characteristics of HA gene of H3N2 human influenza A viruses between 2007 and 2013 in Nanjing,Jiangsu Province,China

We conducted analysis on the molecular characteristics of haemagglutinin of influenza A (H3N2) from 2007 to 2013 in Nanjing. Influenza A virus were isolated and cultured in MDCK cells, and then PCR amplifications and sequencing of the HA genes were carried out. Data were analyzed by DNAStar, MEGA software. Results showed that the incidence of crowd were under 15 years old. The onset time showed obviously seasonal. The phylogenetic tree of isolates strains from 2007 to 2013 could be divided into three branches; there are some antigen sites and receptor binding sites of amino acid substitutions between isolate strains and vaccine strains; the difference also occurred between isolate strains in different years. There are two waves appear of influenza A (H3N2) virus infection during 2007 to 2013 in Nanjing city, maybe result from genetic mutation and recombination. In conclusions, the amino acid mutations of antigen sites and receptor binding sites could make great challenges for influenza prevention and control and the protection effect of vaccine.