2009年-2011年江西省新型甲型H1N1流感病毒HA1基因进化分析

Evolution analysis of HA1 gene of pandemic influenza H1N1 virus in Jiangxi province during 2009-2011

目的分析江西省2009年-2011年新型甲型H1N1流感病毒HA1基因的特点,了解江西省流感病毒变异情况及WHO推荐疫苗株对人体的保护作用,为新型甲型H1N1流感的监测和防控提供理论依据。方法采集监测医院和疑似流感疫情的流感样病例鼻咽拭子标本进行流感病毒分离,从江西省流感监测网中随机选择19株新型甲型H1N1流感病毒,经核酸提取和one-step RT-PCR扩增HA1基因片段,双向序列测定,采用DNAStar 5.0和MEGA 3.0软件分析HA1基因特征。结果 2009年-2011年江西省新型甲型H1N1流感病毒HA1基因序列与疫苗推荐株具有高度同源性,但毒株变异位点逐年增加,部分变异在抗原决定簇位点。结论目前的疫苗仍对人群有保护作用,但存在新型甲型H1N1流感再次流行的风险。

Objective To analyze the characteristics of HA1 gene of pandemic influenza H1N1 virus in Jiangxi province during 2009 -2011, and know the mutation of influenza viruses in Jiangxi province and the protection effect of the vaccine strain rec- ommended by WHO, so as to provide basis for the surveillance of pandemic influenza H1 N1 virus. Methods The specimens of nasopharyngeal swabs were collected from influenza like cases of monitor hospitals and influenza epidemic situation. 19 strains of pandemic influenza H1N1 virus were randomly selected for detection and virus RNA were extracted. Fragments of HA1 genes were amplified by one -step RT- PCR and then were sequenced. The data obtained were analyzed with the software DNAStar 5.0 and MEGA 3.0. Results There was high homology of HA1 between pandemic influenza H1N1 virus isolates from Jiangxi province during 2009 -2011 and the vaccine strain recommended by WHO. However, strain variation sites increases every year and some mutation sites of amino acid existed in antigen determinant sites. Conclusion The vaccine produced by pandemic in- fluenza H1NI vaccine strain recommended by WHO had protective effect. There is still the risk of pandemic influenza H1 N1 ep- idemic.