广州市甲型H1N1流感病毒的持续进化变异监测

  目的  通过对H1N1流感病毒进行基因进化变异监测，为H1N1流感的科学防控提供研究数据。  方法  对广州市2017-2019年132株H1N1流感病毒进行血凝素(Hemagglutinin, HA)和神经氨酸酶(Neuraminidase, NA)基因测序，分析不同流行年度病毒的分子变异特点。  结果  2017-2019年广州市H1N1流行株HA和NA基因均聚为一簇，提示具有相同进化起源。2019年分离株依次由2017年分离株经2018年分离株过度进化而来，呈现较为明显的时间进化趋势。HA基因持续变异的抗原位点主要分布在91、181、202位，其中2018年H1N1流行株HA蛋白抗原位点的变异具有较为明显的多样性。2017和2019年流行株中有3株病毒发生NA蛋白H274Y神经氨酸酶抑制剂的耐药突变。  结论  广州市2017-2019年H1N1流行株与同年度疫苗株的匹配性较好，但病毒基因在持续进化和变异，在抗原位点和耐药位点上不同流行年份表现基因多态性。

Continuous monitoring of evolution and variation of influenza A(H1N1)viruses in Guangzhou,2017-2019

Objective The characteristics of the evolution and variation of influenza A(H1N1)viruses in Guangzhou were monitored,which could provide research data for the scientific prevention and control of influenza A(H1N1).Methods The Hemagglutinin(HA)and Neuraminidase(NA)genes of 132 isolates of influenza A(H1N1)virus were sequenced isolated in Guangzhou from 2017 to 2019.The molecular characteristics of viruses in different epidemic years were analyzed.Results The HA and NA genes of H1N1 epidemic strains were clustered together,suggesting that they had the same evolutionary origin.The isolates in 2019 evolved from the isolates from 2017 to 2018 successively,which showed an obvious trend of evolution.The mutated antigenic sites of HA protein were at 91,181 and 202 sites.Especially,the antigenic variations of HA protein of H1N1 epidemic strain in 2018 had diversities.In 2017 and 2019,three isolates were detected,which had H274Y resistance mu-tation of neuraminidase inhibitor.Conclusions The match between H1N1 epidemic strains from 2017 to 2019 and vaccine strains in the same year in Guangzhou was good.But,the HA and NA genes were evolving and mutating continuously.Gene polymorphisms were found at antigen sites and drug resistance sites.