2013-2017年内蒙古自治区甲型H1N1流感病毒基因特征分析

Analysis of genomic characteristics of influenza A (H1N1) pdm09 viruses in Inner Mongolia, 2013-2017

目的了解内蒙古自治区甲型H1N1流感病毒基因变异特征和规律,为评估疫苗防治效果和防控甲型H1N1流感提供科学依据。方法随机选择2013—2017年内蒙古自治区16株甲型H1N1流感病毒分离株,通过RT-PCR和测序方法获得血凝素(hemagglutinin,HA)和神经氨酸酶(neuraminidase,NA)基因组序列,运用生物信息学软件对全基因序列特征进行分析。结果相对于A/California/07/2009疫苗株,2014年起内蒙古自治区的甲型H1N1流感病毒变异较大,与疫苗株匹配效果不佳,但与A/Michigan/45/2015疫苗株匹配效果较好;部分毒株HA基因中出现D222N和D222G变异,增加了病毒结合人体下呼吸道的能力;部分毒株NA基因中出现E119K和H275Y变异,提示病毒对NA抑制剂出现耐药。结论随着时间推移,甲型H1N1流感病毒已逐渐发生变异,WHO推荐疫苗相对滞后。人群中出现毒力增强株和耐药株,需加强流感病毒基因监测以及时发现新变异株,为流感防控提供依据。

Objective To evaluate the effect of vaccine and provide scientific evidence for prevention and control of influenza virus,this study aims to analyze the characteristics of genomic variation of influenza A(H1N1)pdm09 viruses in Inner Mongolia.Methods The 16 viral strains were selected randomly according to the influenza A(H1N1)pdm09 viruses isolated from network laboratories in Inner Mongolia,2013-2017.The hemagglutinin(HA)and neuraminidase(NA)genomic sequences were obtained by using RT-PCR and sequencing,and genomic characteristics were analyzed via bioinformatics.Results Compared to the A/California/07/2009 vaccine strain,the relatively obvious variation of antigen of influenza A(H1N1)pdm09 viruses in Inner Mongolia since 2014,and the vaccine provided a poor protection to influenza A(H1N1)pdm09 virus infection,while the A/Michigan/45/2015 vaccine strain recommended by WHO recently has a satisfactory protective effects.Several viral isolates from Inner Mongolia increased the binding force of virus in human upper respiratory tract because of D222N and D222G substitution within HA.E119K and H275Y substitution within NA gene of viral strains,suggesting that the viruses were resistant to NA inhibitors.Conclusions The influenza A(H1N1)pdm09 viruses had gradual variations as time went on,and the WHO recommended vaccine was relatively lagging.Virulent strains and drug-resistant strains appeared in the population,and the genetic characteristics of influenza virus surveillance should be strengthened to find the new mutants of virus in time,which provide evidence for the prevention and control of influenza.