2013年宜春市甲型H1N1流感病毒分离鉴定及HA基因分子进化分析

目的 对2013年江西省宜春市甲型H1N1流感病毒HA基因序列及其编码的氨基酸序列进行分子进化分析,为防控甲型H1N1流感大流行和常规监测提供科学根据。方法 随机选择11株2013年宜春市疾病预防控制中心流感监测实验室分离到的甲型H1N1流感病毒毒株,提取病毒RNA,One-step RT-PCR扩增HA基因并双向测序。以世界卫生组织疫苗推荐株A/California/07/2009(H1N1)(GenBank:CY121680)和几株国内外近几年分离的流感甲型H1N1毒株的HA基因为参考序列,采用DNAStar 7.0和Mega 5.0软件对HA基因及其编码的氨基酸序列进行比对,绘制分子进化树,进行HA变异分析。结果 2013年宜春市11株所测甲型H1N1流感病毒与疫苗推荐株亲缘性较近,进一步参考几株国内外近几年分离到的流感甲型H1N1毒株,HA没有发生较大变异;其HA基因序列二硫键、糖基化位点未发生变异;尽管有7株毒株同时在抗原决定簇区A区和受体结合位点130环或其附近发生单个位点氨基酸替换变异,但未形成流行病学变异新种。结论 目前的甲型H1N1流感疫苗仍对人群有保护作用,而抗原决定簇和受体结合位点的变异提示仍需要密切关注甲型H1N1流感的再次流行。

HA gene molecular evolution analysis of influenza A (H1N1) pdm09 virus in Yichun, 2013

Objective To understand the molecular evolution of HA genes and encoding amino acid sequence of influenza A (H1N1) pdm09 virus in Yichun in 2013, and provide scientific evidence for the prevention and control of the infection with influenza A (H1N1) pdm9 virus. Methods Eleven strains of influenza A (H1N1) pdm09 virus isolated in Yichun CDC influenza laboratory were randomly selected, and the virus RNA were extracted. The fragments of HA genes were amplified by using one-step RT-PCR and then sequenced. The nucleotide sequences and amino acid sequences of HA genes were analyzed with software DNAStar 7.0 and Mega 5.0. Results There was a high homology of HA genes between the 11 virus strains isolated in Yichun in 2013 and the vaccine strain A/California/07/2009 (H1N1) (GenBank:CY121680) recommended by WHO, HA did not have a large variation. The disulfide bonds and glycosylation sites of HA gene sequences did not mutate. Although there were 7 strains with simultaneously single site amino acid substitution mutation in the antigen determinant region A and the receptor binding site ring 130 or its vicinity, the new species variation with epidemiological significance did not form. Conclusion The vaccine of pandemic influenza H1N1 recommended by WHO still had certain protective effect. However, the variations of epitope region A and receptor binding site suggested that it is still needed to pay a close attention to the epidemic caused by influenza A (H1N1) pdm09 virus.