2017—2018年广东省H9亚型禽流感病毒HA基因序列分析

Analysis on Hemagglutinin Gene Sequence of H9 Subtype Avian Influenza Virus in Guangdong Province during 2017 to 2018

为了解广东省H9亚型禽流感病毒HA基因变异情况,对2017—2018年从广东省活禽市场获得的13株H9亚型禽流感病毒HA基因进行序列分析,发现13个毒株均属于h9.4.2.5分支;潜在的糖基化位点均为8个,主要变异表现在218~220aa处1个位点缺失和313~315aa处1个位点增加;受体结合位点主要表现为K149N、A150T、V198T、Q234L和Q235M突变,其中234~236aa位点突变为LMG,与人源受体相同,具有可感染人的分子特征;抗原性相关位点除201aa位点较为保守外,其余6个位点主要表现为G90E、S145D、D153G、N167G、A168N、T200R位点的突变,此外168aa由天冬氨酸(D)突变为天冬酰胺(N),并成为主要氨基酸。以上基因突变提示,当前流行毒株的抗原性可能发生了较大变异,现有疫苗株可能对流行毒株不能提供有效的保护,需要研发新的疫苗毒株。

In order to identify all variations of hemagglutinin(HA)gene of H9 subtype avian influenza virus(AIV) in Guangdong province,the HA gene of 13 strains of H9 AIV collected from live poultry markets in the province from 2017 to 2018 was sequenced and analyzed,it was found that all the 13 strains belonged to h9.4.2.5 branch,with eight potential glycosylation loci,and the main variations included a missing locus at 218–220 aa and an increasing one at 313–315 aa. The variations of K149N,A150T,V198T,Q234L and Q235M mainly appeared in receptor binding loci,of which 234–236 aa locus mutated into LMG,with the molecular characteristics that could infect human same as human receptors. For antigen correlation loci,the variations of G90E,S145D,D153G,N167G,A168N and T200R mainly occurred in six loci,except 201 aa that was more conservative. As the main amino acid,168 aa mutated into asparaginate(Asn)from aspartate(Asp). Therefore,as it was indicated that great variations might appear in the antigenicity of current strains that might not be effectively controlled by current vaccines,so it was necessary to develop new vaccines.