2015—2018年广东省H3N2亚型流感病毒分子特征研究

摘要

目的 了解广东省2015—2018年H3N2亚型流感病毒的抗原特性、基因变异情况和进化趋势.方法 测定广东省2015—2018年分离的60株H3N2亚型流感毒株血凝素(hemaglutinin,HA)基因和神经氨酸酶(neuramindase,NA)基因序列,对HA和NA基因的分子特征进行分析.结果 与2015—2018年各年度疫苗株相比,分离的60株病毒中,HA基因的共同氨基酸变异位点为P194L(B区),其中,57株分离株均出现S138A突变.此外,所有分离株中多了4个氨基酸突变位点,即R140I、G142K、V186G和Y219S.分离株NA基因的共同氨基酸变异位点为I231V,比2016—2017年和2017—2018年疫苗株多了K148T突变.结论 广东省2015—2018年优势流行株与我国整体优势流行株稍有差异.多株分离株发生关键氨基酸位点N121K和R142G/K突变,表明H3N2亚型流感病毒有持续突变的趋势,需要引起重视.%Objective To understand the antigenic characteristics, genetic variation and evolutionary trend of influenza A(H3N2) virus strains in Guangdong province from 2015 to 2018. Methods The hemaglutinin (HA) gene and neuramindase (NA) gene of 60 strains of influenza A(H3N2) isolated from 2015 to 2018 in Guangdong province were sequenced and the molecular characterizations of HA gene and NA gene were analyzed. Results Comparing to the vaccine stains from 2015 to 2018, the common amino acid mutation site on the HA genes of the 60 isolated strains was P194L (region B) among which 57 stains showed the mutation of S138A. The four more amino acid mutations on HA gene of all isolated strains were R140I, G142K, V186G and Y219S. The common amino acid mutation site on the NA gene of all isolated strains was I231V. The one extra amino acid mutation on the NA gene of all isolated strains was K148T comparing to vaccine strains of 2016-2017 and 2017-2018. Conclusions The isolated stains in Guangdong province from 2015 to 2018 showed slightly difference from the predominant stains in China. Key mutations, N121K and R142G/K occurred in a number of stains, indicating a trend of persistent mutations in influenza A(H3N2) virus and should be concerned.