重庆市2009～2014年甲型 H1N1流感病毒分离株 HA基因变异分析

目的：对2009～2014年分离得到的甲型H1N1流感病毒进行血凝素（HA）基因测序分析，与世界卫生组织（WHO）推荐疫苗株A／California／07／2009（H1N1）比对，研究其基因变异情况。方法按分离时间及地点不同，选取47株2011～2014年分离得到的甲型H1N1流感病毒进行测序，同时选取既往已有的25株2009年甲型H1N1流感病毒的序列结果，经分子生物学软件进行核苷酸及氨基酸序列分析，并绘制系统进化树。结果2009、2011～2014年的新型甲型 H1N1流感病毒与疫苗株均位于一个大的分枝下，各病毒间的关系均较近。72株分离株的 H A基因总的核苷酸差异在0～2．7％之间，氨基酸差异在0～3．1％之间；与疫苗株A／California／07／2009（H1N1）的核苷酸差异在0．4％～2．4％之间，氨基酸差异在0．9％～3．1％之间。氨基酸变异情况随着年份增加累积得更多，但在氨基酸序列上仍显示为低致病性流感病毒特征；2009年有9株病毒株丢失481位的糖基化位点，2013年有6株病毒株增加位于162位的糖基化位点。结论 WHO推荐的甲型 H1N1疫苗总体上对重庆地区的人群仍有较好的保护作用，但随着时间推移，部分甲型 H1N1流感病毒株可能已发生抗原漂移，需继续对其监测。

Variation of HA gene of influenza A H1N1 influenza virus isolated from 2009 to 2014 in Chongqing city

Objective In order to analyze the variation of HA genes of influenza viruses (H1N1) by being compared with the vaccine strain A/California/07/2009(H1N1) recommended by WHO ,influenza viruses (H1N1) isolated from 2009 to 2014 were selected to do this study .Methods According to the different isolating time and place ,47 strains of H1N1 collected from 2011 to 2014 were selected .Then the 47 strains′ nucleotide sequence of HA genes which were sequenced in the study and other 25 se‐quences of HA genes which were sequenced in 2009 were collected .Nucleotide and amino acid sequences were analyzed by using molecular biology software ,and the phylogenetic trees were drawn .Results A total of 72 strains isolated from 2009 to 2014 were closely related to the vaccine strain A/California/07/2009(H1N1) ,the nucleotide variance and amino acid variance between the 72 strains were 0-2 .7% and 0-3 .1% respectively .Compared with the vaccine strain A/California/07/2009(H1N1) ,the nucleotide variance and amino acid sequence variance were 0 .4% -2 .4% and 0 .9% -3 .1% respectively .The amino acids sequence indicated that ,although the variance was increased by years ,the H1N1 viruses were still showed characteristics of low pathogenic influenza viruses .It was also found that there were 9 strains lost their potential glycosylation site at HA protein site 481 in 2009 ,while in 2013 there were 6 strains got new potential glycosylation sites at HA protein site 162 .Conclusion The vaccines (H1N1) recom‐mended by WHO was still protective to people in Chongqing .But as time goes by ,antigen drift may occur in some new antigenic drift strains and the routine monitoring of influenza viruses should be continued .