2011 - 2016年云浮地区新甲型H1N1流感病毒血凝素基因进化与变异

目的 分析2011 - 2016年云浮地区新甲型H1N1流感病毒血凝素（HA）基因进化特征及抗原表位变异特征。方法 收集流感监测哨点医院流感样病例咽拭子标本，通过MDCK细胞对标本进行病毒分离。按时间顺序选取19株云浮地区新甲型H1N1流感毒株，对HA基因进行测序。与Genbank中13株参考毒株相应序列比较，用BioEdit5.0、MEGA6.0软件构建HA基因系统进化树，进行核苷酸序列同源性和氨基酸位点变异分析。结果 19株毒株HA核苷酸序列高度相似；进化树可分为三大分支，各具基因特征。在19株毒株HA中发现45个氨基酸位点变异，其中有6个高频变异位点:P100S 、S202T/N、S220T、I338V、E391K、S468N；发生在抗原决定簇上的变异位点有位于Sa区的N142S、G172E、S179N、K180Q，Sb区的S202T/N和Ca区S220T；2016年分离的3株毒株中，抗原决定簇发生了Sa区S179N和K180Q、Sb区S202T和Ca区S220T变异。结论 云浮地区新甲型H1N1流感病毒HA蛋白在某些氨基酸位点发生了突变，抗原决定簇Sa、Sb 和Ca区的氨基酸位点发生了变异，2016年云浮地区可能出现了新甲型H1N1流感新变异株。

Evolution and mutation of hemagglutinin gene of novel influenza (H1N1) virus in Yunfu area from 2011 to 2016

Objective The study aimed to analyze the characteristics of hemagglutinin(HA) gene evolution and mutation of antigenic epitopes of novel influenza(H1N1) virus in Yunfu area from 2011 to 2016. Methods Throat swab specimens of influenza-like cases were collected from surveillance sentinel hospitals, and influenza viruses were isolated by MDCK cells. 19 H1N1 virus strains were selected in chronological order, and the HA gene was sequenced. Compared with the corresponding sequence of 13 reference strains in Genbank, the phylogenetic tree of HA gene was constructed by BioEdit5.0 and MEGA6.0 software, and the nucleotide sequence homology and the variation of amino acid site were analyzed. Results The nucleotide sequence of HA in 19 strains were highly similar. Phylogenetic trees of all 19 were divided into 3 branches, each with genetic characteristics. 45 amino acid sites were found in 19 strains of HA. There were 6 high frequency variation sites, P100S, S202T/N, S220T, I338V, E391K, S468N, respectively. The mutation sites occurring on antigenic determinants included N142S, G172E, S179N, K180Q in Sa region, S202T/N at Ca region and S220T in Sb region. Among the 3 strains isolated in 2016, the antigenic determinants developed S179N and K180Q in the Sa region, S202T in the Sb region, and S220T mutation in the Ca region. Conclusion The HA gene of H1N1 virus in Yunfu area has been mutated at some amino acid sites, and the amino acid sites in the epitope Sa, Sb and Ca regions of the antigen epitopes have been mutated. A new variant of H1N1 strain may appear in Yunfu area in 2016.