2009至2016年中国甲型H1N1流感病毒神经氨酸酶基因进化分析及流行趋势预测

Evolution analysis and trend prediction of neuraminidase gene of influenza A/H1N1(09pdm) virus in China from 2009 to 2016

目的分析2009至2016年中国甲型H1N1流感病毒神经氨酸酶基因(NA)进化特征,预测其流行趋势,为流感疫苗评价提供依据。方法从全球共享禽流感数据倡议组织(GISAID)数据库及美国国家生物技术中心(NCBI)数据库下载甲型H1N1流感病毒NA基因序列1 141条。利用邻接法进行系统进化分析和遗传变异分析,利用Bayesian skyline Plot预测流行趋势。结果 2009至2016年中国甲型H1N1毒株NA基因与参考毒株的同源性逐年降低。遗传进化分析显示同一年份的毒株在系统进化树上基本呈现集中分布。除2012年,其余各年份的毒株均通过不同模型得到正向压力选择位点。动力学分析显示2017年甲型H1N1可能达到一个流行高峰。结论甲型H1N1流感病毒NA基因所编码的氨基酸逐年变异,需进一步加强流感监测。

Objective To analyze the evolutionary characteristics and predict the variation trend of neuraminidase（ NA） gene of influenza A/H1N1（ 09pdm） virus in China from 2009 to 2016 in order to provide the basis of assessment for flu vaccines. Methods A total of 1 141 sequences of NA gene of influenza A/H1N1（ 09pdm） virus were screened out from the Global Initiative on Sharing All Influenza Data and National Center for Biotechnology Information. The phylogenetic trees and the mutations of amino acids sequences were constructed and analyzed by biological softwares. The prediction for epidemic trend of influenza was analyzed by Bayesian skyline Plot. Results Compared with the sequence of reference strain,the homology of nucleic acid sequence of NA gene decreased year by year from 2009 to 2016. The phylogenetic analysis showed that NA gene clustered nearly on the identical phylogenetic tree in one year.The positive selection pressure site of NA strain was observed by different models in each year except 2012. The dynamics analysis showed that the popularity of influenza A/H1N1 virus may continue to increase to a peak in 2017. Conclusion The amino acid encoded by NA gene of influenza A/H1N1 virus is varying gradually,so the importance of surveillance for influenza virus should be reinforced for every year.