新型H1N1流感病毒HA基因特性分析

Analysis on the HA gene Characteristics of Novel Influenza A(1H1N1) Virus

目的:了解新甲型H1N1流感病毒HA基因特性。方法:设计3对引物,对9株天津地区新甲型H1N1流感病毒阳性的咽拭子标本核酸进行RT-PCR扩增,后对产物测序,将测序结果通过软件进行拼接,得到HA基因全长,分析序列特征并绘制种系发生树。结果:9株新甲型H1N1流感病毒HA基因片段测序成功,经序列拼接后,长度为1778 bp,截取开放读码框内1702 bp核苷酸,绘制了种系发生树。新甲型H1N1流感病毒HA基因与经典的猪流感病毒亲缘关系最近,聚在一个分支上。天津地区新甲型H1N1流感病毒HA蛋白氨基酸与WHO推荐的疫苗株A/California/07/2009(H1N1)及中国的代表株A/Sichuan/1/2009(H1N1)相比,同源性很高,为98.8%～99.6%。氨基酸序列与WHO推荐的疫苗株A/California/07/2009(H1N1)相比,有4个位点发生变异,与中国的代表株A/Sichuan/1/2009(H1N1)相比,有3个位点不同。结论:新甲型H1N1流感病毒HA基因源于经典猪流感病毒,目前的新甲型H1N1流感病毒的HA蛋白变异还很小,但应密切关注该病毒的变异情况。

Objective：To understand the genetic characteristics of novel influenza A（H1N1） viruses circulated in 2009.Methods： 3 pairs of primers were designed to amplify the HA gene of 9 novel influenza A（H1N1） viruses detected in Tianjin.Then PCR products were sequenced,and were spliced together to obtain the complete HA gene.Phylogenetic and characteristic analysis of HA gene were performed.Results： All the HA sequences of 9 novel influenza A（H1N1） viruses were amplified successfully.After splicing,the complete HA gene was 1778bp in length.Phylogenetic tree was constructed using 1702 bp in open reading frame.HA genes of novel influenza A（H1N1） viruses gathered together with classical swine influenza A（H1N1）.The high identities（98.8%-99.6%） of HA gene were observed between novel influenza A（H1N1） isolated in Tianjin and WHO recommended vaccine strain A/California/07/2009（H1N1） and China representative strain A/Sichuan/1/2009（H1N1）.The amino acid sequences on HA domain protein were similar to A/California/07/2009（H1N1） and A/Sichuan/1/2009（H1N1）,but still have 4 and 3,respectively,amino acid sequence differences.Conclusion： HA gene of novel influenza A（H1N1） viruses originated from classical swine influenza viruses.The variation of HA gene in novel influenza A（H1N1） viruses was not so significant,but we still have to surveillance the variation closely.