2013年深圳市新甲型H1N1流感病毒分子变异研究

The study of molecular variation of new influenza virus H1N1 in Shenzhen in 2013

目的了解2013年深圳市新甲型H1N1流感病毒的分子变异情况。方法用MDCK细胞进行流感病毒分离,收获病毒后提取病毒RNA作为模板,利用RT-PCR对其HA基因进行扩增,扩增产物经琼脂糖凝胶电泳鉴定后测序,测序结果用Clustal W2和MEGA3.1软件进行序列分析。结果 2013年的深圳毒株与同年国内外的流行株差异不大,但与同期国际疫苗株A/California/7/2009相比,在进化树上已经产生了明显的分离,且出现了2个不同的进化分支;HA分子有多个氨基酸位点发生了变异,其中有4个变异位点位于抗原决定簇区域内:抗原决定簇Sa的135位点由N变成了S,163位点的K出现了N/Q/I的多元突变;抗原决定簇Sb的185位点由S变成了T;抗原决定簇Ca1的203位点由S变成了T,这些变异的出现会导致病毒抗原性的改变。结论 2013年深圳市流行的新H1N1病毒有较大可能会形成一个新的优势流行株。

Objective To study the molecular variation of new influenza virus H1N1 in Shenzhen in 2013. Methods Influenza viruses were isolated by MDCK cell culture,and the RNA of received virus was extracted as model. HA genes were amplified by RT- PCR. After sequencing,phyletic evolution and molecular variation analysis of HA gene were conducted by Clustal W2 and MEGA3. 1 program. Results H1N1 viruses in 2013 in Shenzhen had little difference with the epidemic strains of this year.But it had already separated from the vaccine strain A / California /7 /2009 in the phylogenetic tree,and formed two different clades. HA molecular variation happened on multiple amino acids,of which there are four variable loci located in antigenic determinant cluster region,the 135 sites of antigenic determinant cluster Sa turned N into S,K on the 163 sites appeared multiple mutation N / Q / I; epitope sites of 185 Sb clusters turned S into T; these variations would lead to changes in the virus antigenicity. Conclusion The H1N1 virus in 2013 which predominated in Shenzhen is likely to form a new epidemic stains.