菏泽市2016-2021年乙型B-Victoria系流感病毒全基因组测序分析

Whole-genome Sequencing of the B-Victoria Strain of Influenza Virus in Heze City,China,from 2016 to 2021

为了解2016-2021年菏泽市B-Victoria系流感病毒的遗传突变机制,掌握流感病毒的分子进化规律以及流感疫苗的研发提供依据。选取菏泽市2016-2021年B-Victoria系流感病毒毒株16株,利用二代Ilumina MiSeq测序得到全基因组顺序,利用生物信息学软件构建体系进化树,解析HA和NA基因组的突变规律。16株流感病毒可分成四个进化分支,2株毒株(2016年)隶属V1A进化分支,8株毒株(4株2019年,4株2020年)隶属V1A.3进化分支,4株毒株(2021年)隶属V1A.3a.1进化分枝,2株毒株(2021年)为V1A.3a.2进化分枝。以疫苗株B/Brisbane/60/2008为标准株,HA基因中共有16个位点出现突变,其中有10个位点设在抗原决定簇上。NA基因变目前已有21个位点出现了突变,在关键耐药位点上还未监测到变异。糖基化位点分析结果显示,2021年病毒株HA基因与其他病毒株相比少一个糖基化位点197NET,NA基因组糖基化位点并没有改变。结果提示2019年和2021年菏泽市BVictoria系流感病毒HA基因可能发生了抗原漂移,但所有毒株NA基因突变均未涉及到耐药位点突变,表明菏泽市B-Victoria流感的NA基因耐药性尚未发生改变。

We wished to analyze the genetic characteristics of the B-Victoria strain of influenza viruses in Heze City,China from 2016 to 2021,and provide a reference for influenza vaccines.Sixteen B-Victoria influenza virus strains were collected in Heze City,China from 2016 to 2021.Whole-genome sequences of nucleic acids were obtained on the MiSeq M platform(Ilumina).Bioinformatics analysis was done by constructing 4V phylogenetic trees and screening variants of amino acids in HA and NA genes.Sixteen B-Victoria influenza virus strains were categorized into four clade lineages.Two strains(2016)were attached to the V1A clade.Eight strains(2019,2020)were attached to the V1A.3 clade.Eight strains(2019,2020)were attached to the V1A.3 clade.Four strains(2021)were attached to the V1A.3a.1 clade.Two strains(2021)were attached to the V1A.3a.2 clade.Sixteen amino-acid changes(of which 10 were located in antigenic determinants)were detected in the HA gene.Twenty-one amino-acid changes(of which none occurred at enzyme catalytic sites)were detected in the NA gene.Glycosylation analysis revealed deletion of a 197NET glycosylation site in the HA gene(2021),and a mutation was not found in the NA gene.In 2019 and 2021,the HA gene of the BVictoria influenza virus in Heze City,China may have antigenic drift,but the NA-gene mutation of all strains did not involve mutation of drug-resistance sites.Hence,the NA-gene resistance of the B-Victoria influenza virus in Heze City,China has not changed.