2013-2018年度滨州市B型流感病毒血凝素和神经氨酸酶基因进化特征分析

目的  分析滨州市2013-2018监测年度B型流感病毒血凝素(hemagglutinin, HA)、神经氨酸酶(neuraminidase, NA)基因突变及其抗原变异特征。 方法  采集滨州市2013-2018年的流感监测哨点医院流感样病例(influenza-like illness, ILI)咽拭子标本进行病毒分离, 选取29株B型流感分离代表毒株进行HA、NA基因序列测定, 通过基因分析软件进行同源性比对、构建HA、NA基因进化树。 结果  2013-2018各年度B型流感占比分别为47.0%、23.0%、31.0%、7.2%和65.1%, 差异有统计学意义(χ²=1 485.143, P < 0.001)。2013-2014年度分离株与当年世界卫生组织推荐的疫苗株匹配度差。2013-2014年度流行的B型流感病毒为Yamagata系HA与Victoria系NA基因的重配株。 结论  2013-2018监测年度, 滨州市B型流感病毒的进化是通过系间基因重配、不同谱系共流行、连续不断的不同抗原谱系的更替来完成的。

Phylogenetic analysis of influenza B hemagglutinin and neuraminidase gene in Binzhou City from 2013 to 2018

Objective To investigate the mutation of hemagglutinin(HA),neuraminidase(NA)gene and amino acid variation of influenza B.Methods Throat swab specimens were taken from patient with influenza-like illness(ILI)and were investigated for the influenza virus identification from 2013 to 2018,and 29 strains of influenza B viruses were selected.HA,NA gene sequencing of the viruses were performed and were aligned using molecular evolutionary genetics analysis software.The phylogenetic tree was constructed.Results During the influenza seasons from 2013 to 2018,the detection rates of influenza B virus were 47.0%,23.0%,31.0%,7.2%and 65.1%,respectively.Statistically significant differences between the proportion of influenza B viruses were observed(χ~2=1485.143,P<0.001).The isolates from 2013 to 2014 did not correspond to vaccine strain,which was recommended by world health organization for the influenza season.Conclusions The evolution of influenza B virus was achieved through interlineal gene recombination,co-prevalence of different lineages,and continuous replacement of different antigenic lineages in Binzhou from 2013 to 2018.