2013-2017年中国甲型H7N9流感病毒血凝素基因进化分析

发布时间：2018-03-07 04:06

本文选题：甲型HN流感病毒　切入点：血凝素　出处：《医学研究生学报》2017年10期 　论文类型：期刊论文

【摘要】：目的甲型H7N9亚型流感病毒对人具有较高致死率,了解该病毒在我国的流行态势具有重要意义。文中旨在研究2013-2017年中国地区H7N9亚型禽流感病毒血凝素(HA)基因的变异情况和进化特征。方法从全球共享禽流感数据倡议组织和美国国家生物技术中心流感病毒数据库下载2013-2017年中国地区甲型H7N9流感病毒HA基因序列,利用生物信息软件进行基因同源性分析、HA分子特征分析、系统进化分析及选择性压力分析。结果同源性分析结果显示,2013-2017年毒株的HA基因与参考毒株的同源性分别为99.0%~99.9%、98.7%~99.5%、98.4%~99.6%、76.8%~99.4%、69.9%~98.2%,同源性逐年降低。HA分子特征分析结果显示,与参考毒株相比,抗原位点发生变异的有21处,其中A区的148位、C区的285位氨基酸位点的突变频率最高;N285D的变异在2015年最高,达到23%;R148K的突变率逐年升高,在2016年和2017年分别达到65%和78.5%。系统进化分析结果显示,2013-2017年同一年份的H7N9亚型流感病毒毒株在系统进化树当中基本呈现集中分布状态;2013年大部分来自广东的毒株存在T140A的氨基酸替换。2014年毒株分布范围最广。选择性压力分析结果显示,2015年序列通过FEL和IFEL模型均得到正向选择压力位点65,2016年和2017年毒株未得到正向选择压力位点。结论甲型H7N9流感病毒逐年发生变异,且H7N9的毒株变异来源逐渐增加,加大了预防和控制的难度,应进一步加强监测,以应对病毒对宿主的不断适应和突变。
[Abstract]:Objective A H7N9 subtype influenza virus has a high mortality in human. It is important to understand the epidemic situation of H7N9 avian influenza virus in China. The aim of this paper is to study the variation and evolutionary characteristics of H7N9 avian influenza virus hemagglutinin (H7N9) gene in China during 2013-2017. The organization and the National Center for Biotechnology of the United States downloaded the HA gene sequence of influenza A H7N9 virus from 2013-2017 in China. Using bioinformatics software to analyze the homology of genes and the molecular characteristics of HA. Phylogenetic analysis and selective pressure analysis. Results the homology of HA gene and reference strain in 2013-2017 were 99.00.99. 9% and 98.775%, respectively. The homology of HA gene decreased year by year. Compared with the reference strain, the homology of HA gene decreased year by year, compared with the reference strain, and the homology of HA gene decreased year by year, compared with the reference strain, the homology analysis showed that the homology of HA gene and the reference strain were 99.0%, 99.7% and 99.7%, respectively, and the results showed that the homology of HA gene was significantly lower than that of the reference strain. The mutation frequency of the 285 amino acid loci in A region 148 and C was the highest in 2015, and the mutation rate of 23g R148K was increased year by year, and the mutation frequency of N285D was the highest in 2015. It reached 65% and 78.5 in 2016 and 2017, respectively. The results of phylogenetic analysis showed that the H7N9 subtype influenza virus strains in the same year 2013-2017 showed a concentrated distribution in the phylogenetic tree, and most of the strains from Guangdong existed in 2013. Amino acid substitution in T140A. In 2014, the virus strain was the most widely distributed. The results of selective pressure analysis showed that the positive selective pressure sites 65 were obtained by FEL and IFEL models in 2015, and no forward selective pressure sites were obtained in 2016 and 2016 strains. Conclusion A H7N9 influenza virus mutates year by year. The source of strain variation of H7N9 increased gradually, which increased the difficulty of prevention and control, so the surveillance should be further strengthened to cope with the constant adaptation and mutation of the virus to the host.
【作者单位】：南京大学生命科学学院;江苏省疾病预防控制中心急性传染病科;
【基金】：国家自然科学基金(31370079)
【分类号】：R511.7

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