2015—2020年黑龙江省乙型流感病毒流行和基因特征分析

Epidemiological and genetic characteristics of influenza B viruses in Heilongjiang Province from 2015 to 2020

目的分析黑龙江省乙型流感病毒流行状况及基因进化特征,为防控乙型流感提供基础数据。方法对2015—2020年黑龙江省流感病毒病原学监测数据进行分析。选取10株B/Victoria系流感毒株及19株B/Yamagata系流感毒株,通过全基因组测序方法获得血凝素(hemagglutinin,HA)和神经氨酸酶(neuraminidase,NA)基因序列,并从全球共享流感数据倡议组织(Global Initiative on Sharing All Influenza Data,GISAID)获取黑龙江省6株B/Victoria系流感毒株基因序列。利用生物信息学软件对黑龙江省35株乙型流感病毒基因序列进行分析。结果16株B/Victoria系流感毒株HA基因均属于V1A分支,其中3株属于以162~164氨基酸位点缺失为特征的V1A.3分支;NA基因进化树与HA一致。19株B/Yamagata系毒株HA基因属于Y3分支;18株B/Yamagata系毒株NA基因属于Y3分支,1株B/Yamagata系毒株NA属于B/Victoria系的V1A分支,为HA-Y3/NA-V1A系间重配株。B/Victoria系毒株在HA蛋白的抗原表位发生了变异,B/Yamagata系毒株抗原表位变异少,未发现耐药位点的变异。结论黑龙江省B/Victoria系毒株在多个HA抗原位点上发生变异,需密切监测流行株的变异情况。

Objective To analyze the epidemiological patterns and genetic evolution of influenza B viruses in Heilongjang Province,providing fundamental data for influenza B prevention and control in the region.Methods Influenza virus etiological surveillance data in Heilongjiang Province from 2015 to 2020 were analyzed.Ten strains of B/Victoria lineage viruses and 19 strains of B/Yamagata lineage viruses were selected for full-genome sequencing to obtain the hemagglutinin(HA)and neuraminidase(NA)gene sequences.Additionally,HA gene sequences of 6B/Victoria lineage strains from Heilongjiang Province were obtained from the Global Initiative on Sharing All Influenza Data(GISAID).Bioinformatics software was used to analyze the genetic characteristics of 35 strains of influenza B viruses.Results The HA genes of 16 B/Victoria lineage strains all belonged to the V1A clade,with three strains belonging to the V1A.3 branch characterized by the deletion of 162-164 amino acid sites.The NA gene phylogenetic tree was consistent with the HA gene.The HA genes of 19 B/Yamagata lineage strains belonged to the Y3 branch;the NA genes of 18 B/Yamagata lineage strains belonged to the Y3 branch,and the NA gene of 1 B/Yamagata lineage strain belonged to the V1A branch of the B/Victoria lineage strain,which was a reassortant strain HA-Y3/NA-V1A.B/Victoria lineage strains had mutations in the HA antigenic sites,while B/Yamagata lineage strains had fewer antigenic site mutations,and no drug resistance mutations were identified.Conclusions B/Victoria lineage strains in Heilongjiang Province had mutations in multiple HA antigenic sites,requiring close monitoring of the evolving epidemic strains.