苏州市甲型H1N1流感病毒HA基因的分子演变和遗传特征分析

目的 对新型H1N1从2009年在苏州出现至2011年度基本消失整个过程中,苏州分离株血凝素( haemagglutinin,HA)基因的变化和分子特征进行了分析.方法 提取苏州分离株的RNA,以WHO推荐的引物扩增HA基因并测序.采用生物信息学软件对苏州毒株的HA进行详细的分子特征分析,并与疫苗株及全球和全国的代表性毒株进行比对分析.结果 与疫苗株相比,5株苏州株的核苷酸序列同源性在98.8％ ～99.4％之间,氨基酸序列同源性在98.8％～99.4％之间.5株苏州株中3株在1个抗原位点突变,2株有2个抗原位点突变,且有2个抗原位点突变的都是2011年分离株.糖基化位点、二硫键和受体结合位点都没有发生改变.5株苏州株和各地的分离株都表现出按年份聚类的特点.结论 详细分析了苏州地区新型H1N1流感病毒HA的分子特征,表明苏州毒株的抗原位点上出现氨基酸残基的变化,但仍处于稳态.

Genetic characterization of haemagglutinin of novel H1N1 influenza viruses in Suzhou City

Objective To investigate the genetic variation and molecular characteristics of HA gene of influenza A （H1N1） virus isolated in Suzhou during from2009 to 2011. Methods Viral RNA of 5 Suzhou isolates was isolated and their HA gene were amplified and sequenced by the primers and protocol recommended by WHO, and the sequences together with other sequences downloaded from GenBank were analyzed by several bioinformatics software. Results Compared with vaccine strain, the average homogeneity of nucleotide and amino acids of 5 Suzhou isolates were between 98.8-99. 4% and 98.8-99.4% respectively. All of the 5 strains have 1 amino acids replacement in Sb region and 2 strains have 2 amino acids replacement in Ca region. Strains from and outside Suzhou both showed a trend of clustering by collection year. Conclusion The Suzhou strains are still in stable condition although 1-2 amino acids replacement had happened in antigenic sites.