2013—2022年安徽省人感染H9N2亚型禽流感病毒分子进化分析

Molecular evolution of human infection with H9N2 subtype avian influenza virus in Anhui province from 2013 to 2022

目的分析2013—2022年安徽省人感染的H9N2亚型禽流感病毒与外环境毒株的遗传进化特点及分子特征,为人感染禽流感防控提供了监测经验。方法选取安徽省流感监测网络实验室中的外环境样本和人源样本,通过鸡胚分离得到63株病毒,采用RT-PCR法扩增后进行全基因组测序,对其生物信息进行分析,构建基因进化树并分析其遗传进化特征以及潜在糖基化位点。结果血凝素(HA)基因属于9.2.4.5支系,蛋白裂解位点绝大部分为"PSRSSR\GL",神经氨酸酶(NA)、碱性蛋白1(PB1)、酸性蛋白(PA)、非结构蛋白(NS)和核蛋白(NP)基因属于F/98支系,基质蛋白(MP)基因属于G1/97支系,碱性蛋白2(PB2)基因属于ST/7488支系。HA蛋白发生了T155N、R164Q、H183N、T189D/V、A190V/T和Q226L突变,NA蛋白发生了62~64位点缺失,PB2蛋白发生了T271A、I292V/M和E627V/L突变,PA蛋白发生了K356R和S409N突变。63株分离株存在6个潜在糖基化位点。结论2013—2022年安徽省外环境和人源采集的H9N2亚型禽流感病毒属于同一进化分支,氨基酸位点突变提示了病毒呈现出一种逐渐适应哺乳动物宿主环境的趋势,因而需进一步研究病毒的适应性进化情况以及开展相关的监测工作。

ObjectiveTo analyze the genetic and molecular characteristics of H9N2 subtype avian influenza viruses from external environment and humans in Anhui Province from 2013 to 2022.MethodsEnvironmental samples and human samples were collected from Anhui influenza surveillance network laboratory.Sixty-three strains of virus were isolated in chicken embryos.RT-PCR was used to amplify the virus and whole genome sequencing was performed.To construct gene evolutionary tree and analyze its genetic characteristics and potential glycosylation sites.ResultsThe hemagglutinin(HA)gene belongs to the 9.2.4.5 clade,and the protein cleavage sites are mostly"PSRSSR\GL".The neuraminidase(NA)gene,basic protein-1(PB1)gene,acidic protein(PA)gene,non-structural protein(NS)gene and nucleoprotein(NP)gene belong to the F/98 clade,the matrix protein(MP)gene belongs to the G1/97 clade,and the basic protein-2(PB2)gene belongs to the ST/7488 clade.Mutations of T155N,R164Q,H183N,T189D/V,A190V/T and Q226L occurred in HA protein,deletion of NA protein occurred at 62-64 sites,and mutations of T271A,I292V/M and E627V/L occurred in PB2 protein.At the same time,mutations of K356R and S409N occurred in the PA protein.ConclusionsThe H9N2 subtype avian influenza viruses collected from external environment and human sources in Anhui province from 2013 to 2022 belong to the same evolutionary branch,and amino acid site mutations suggest that the virus shows a tendency to gradually adapt to the mammalian host environment.Therefore,further studies on the adaptive evolution of the virus and related monitoring work are needed.