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目的分析大连市2005-2009年流感病毒血凝素(HA)基因变异情况。方法采用MDCK细胞分离培养季节流感H1N1亚型28株;H3N2亚型9株;B型(Yamagata系)24株,采用RT-PCR法分节段扩增各毒株血凝素基因,并进一步对各片段进行核苷酸和氨基酸序列测定分析。结果 2005-2009年,大连市分离到的甲型H1N1病毒变异较大,其中2009年分离的一株H1N1亚型毒株A/liaoningxigang/136/2009(H1)与该年WHO推荐的疫苗株相比,抗原决定簇B区上有4个位点发生了突变,属于新的变种。2005、2007年分离的H3N2流感病毒株,与疫苗株相比序列同源性较高,并未发生大的变异;2007-2008年流行的B型Yamagata系病毒与疫苗株B/Shanghai/361/02相比,有7个氨基酸位点发生改变,其中两个位于抗原决定簇,并于196位增加一个糖基化位点。结论各年度WHO推荐的疫苗株与流行株之间匹配性不完全一致,每年由于核苷酸序列的变化而引起了不同程度的抗原性漂移。
Objective To analyze the genetic variation of influenza virus hemagglutinin (HA) gene in Dalian City from 2005 to 2009. Methods 28 strains of H1N1 influenza virus of seasonal flu, 9 strains of H3N2 subtype and 24 strains of type B (Yamagata strain) were isolated and cultured using MDCK cells. The hemagglutinin gene of each strain was amplified by RT-PCR. Each fragment was subjected to nucleotide and amino acid sequence analysis. Results In 2005-2009, there was a large variation in the type A H1N1 virus isolated in Dalian. One strain of H1N1 subtype A / liaoningxigang / 136/2009 (H1) isolated in 2009 and the vaccine strain recommended by the WHO in that year Compared to the antigenic determinant, B region has 4 mutations in the site, belonging to the new variant. The H3N2 influenza virus isolates isolated from 2005 and 2007 had higher sequence homology with the vaccine strains, with no major variation. The strains B / Shanghai / 361 / Compared with 02, seven amino acid sites were changed, of which two were located in the antigenic determinant and a glycosylation site was added at position 196. Conclusion The matching between the vaccine strains recommended by the WHO and the epidemic strains in each year is not exactly the same. Each year, due to the change of nucleotide sequence, some antigenic drift is caused.