一例混合感染病例中季节性H3N2亚型流感病毒HA1和NA基因特异性分析

Analysis of seasonal H3N2 influenza virus HA1 and NA gene in one mixed infection case

目的了解一例新甲型H1N1和季节性H3N2亚型流感混合感染病例中季节性H3N2亚型流感病毒HA1和NA基因的变异情况。方法分离病毒毒株,提取核酸经反转录聚合酶链反应(RT-PCR)方法扩增HA1和NA基因,获得测序结果与WHO推荐2009年-2014年各年的疫苗株和疫苗相似毒株同源比对,使用生物信息软件绘制种系发生树。结果 HA1基因进化树分析表明该毒株与2013年各地区筛选毒株集中于同一分支,与2013年-2014年疫苗株比对共有8个位点的氨基酸发生变化。NA基因与2013年-2014年推荐疫苗相似株同源性比对有2个位点氨基酸发生变化,未出现耐药位点的变异。结论本次研究所分离毒株与2013年-2014年疫苗株和疫苗相似株比对其HA1和NA基因都有变异,并未发现耐药位点的变异。

Objective To analyze the HA1 and NA genetic characteristics of seasonal H3N2 influenza virus in one case of mixed infection with pandemic A（ H1N1 ） and seasonal H3N2. Methods The seasonal H3N2 influenza virus HA1 gene and NA gene were amplified by reverse transcription - polymerase chain reaction （ RT - PCR） and sequenced. The sequence results were compared with those of WHO（2009 -2014） vaccine strains and similar viral strains. Phylogenic analysis was performed by using bioinformatics software. Results HA1 gene analysis showed this seasonal H3N2 influenza virus and those strains from 2013 were in the same phylogenic tree branch. Compared to vaccine strains from 2013 -2014, 8 amino acid locus were found variation in HA1 gene, while NA gene had 2 amino acid mutation locus. The NA related drug resistance mutations were not found. Conclusion Compared to vaccine strains and vaccine - similar strains in 2013 and 2014, both HA1 gene and NA gene of the seasonal H3N2 influenza virus isolates were found genetic mutation and NA drug resistance mutations were not found.