2009年新型甲型H1N1流感病毒全基因组序列重组分析及同源性比对

目的 分析2009年新型甲型H1N1流感爆发以来流感病毒的全基因组进化变异及重组情况.方法 从NCBI基因数据库下载2009年新型甲型H1N1流感病毒(A/H1N1)代表性全基因组序列,先用MEGA4.0软件对8个基因序列片段进行比对和拼接;然后将历史上流行的H1N1、H5N1、H3N2等不同宿主(人、禽、猪)的流感病毒全基因组序列用MEGA做比对拼接,并用NJ法构建进化树.采用Simplot 3.5.1软件分析2009年新型甲型H1N1流感病毒基因重组情况.结果 自2009年3月爆发新型甲型H1N1流感以来,截至9月,病毒基因没有出现变异,同源性为99.69%～99.93%.基因重组分析显示,新型甲型H1N1病毒株PIE、PBI、PA、HA、NP和NS基因来源于近年来北美地区猪源人H1N1,同源性分别为95.25%,95.08%,95.21%,93.52%,95.23%,94.78%;NA和MP与欧洲地区猪H1N1同源性较高,分别为90.21%,94.43%.全基因序列同源性分析发现2009年新型甲型H1N1流感病毒与北美地区猪H1N1病毒同源性最高,为92.22%.结论 2009年新型甲型H1N1流感病毒是由2005年北美地区猪H1N1病毒与欧洲猪H1N1的NA和MP片段重排进化而成,新病毒暂未发生变异,H1N1新流感疫苗具有保护作用.

Recombination analysis and homology alignment of full-length genome sequences of die novel A/H1N1 influenza virus in 2009

Objective To analyze the genetic variation and recombination of the novel A/H1N1 influenza pandemic virus in 2009. Methods Full-length sequence of typical novel A/H1N1 influenza virus was downloaded from NCBI database. MEGA4.0 software was used to connect and align the eight fragments of the virus. Then the fragments of different subtypes such as H1N1, H5N1 and H3N2 of the historical strains from different hosts, including human, poultry and pigs, were connected and aligned in the same way. A phylogenetic tree was constructed by NJ method. The recombination analysis of 2009 pandemic virus was made with Simplot 3. 5.1 software. Results There was no clear variation (identity was 99.69% - 99. 93%) in the novel A/H1N1 influenza virus from April to September, 2009. Simplot and MEGA analysis indicated that the PB2, PB1, PA, HA, NP and NS of the novel A/H1N1 virus might originally evolve from the swine and human H1N1 virus isolated in North America (identity was 95. 25%, 95.08%, 95.21%, 93.52%, 95.23% and 94.78%, respectively). NA and MP showed high homology with the European swine H1N1 virus, the identity was 90.21% and 94.43%, respectively. Full-length sequence of the novel A/H1N1 influenza virus had a highest similarity with swine H1N1 virus isolated from North America (identity was 92.22%). Conclusions The novel A/H1N1 influenza pandemic virus in 2009 was originated from the reassortment and evolution of swine H1N1 2005 pandemic virus in North America, and the NA and MP fragments of European swine H1N1. There is no clear variation in novel influenza virus up to now. The novel A/H1N1 influenza vaccine possesses protective effect.