2019年南宁市季节性甲型H3N2流感病毒流行情况及HA和NA遗传特性分析  

The prevalence and genetic characteristics of the HA&NA genes of seasonal influenza A(H3N2)influenza viruses in the City of Nanning in 2019

作　　者：范云燕[1] 覃健敏[1] 欧嵩凤 汤洪洋[1] 石健[1] FAN Yun-yan;QIN Jian-min;OU Song-feng;TANG Hong-yang;SHI Jian(Nanning Center for Disease Control and Prevention,Nanning 530023,China)

机构地区：[1]南宁市疾病预防控制中心,广西南宁530023

出　　处：《中国病原生物学杂志》2021年第2期193-197,202,共6页Journal of Pathogen Biology

基　　金：广西壮族自治区卫生健康委员会自筹经费科研基金(No.Z20191014)。

摘　　要：目的分析南宁市2019年H3N2流感病毒流行情况及血凝素(HA)基因和神经氨酸酶基因(NA)分子特征,及时掌握本地流感病毒流行动态和进化方向,为流感治疗及疫苗株的筛选提供科学依据。方法从全球共享禽流感数据倡议组织(GISAID)数据库获得2019年南宁市H3N2 HA和NA全长核苷酸序列。用MEGA V7.0和Interactive Tree of Life V5(iTOL V5)软件构建系统发育树,利用NetN Glyc1.0软件预测HA、NA基因糖基化位点,用DNAstar V8.1.3软件对流感病毒的HA和NA同源性、氨基酸变异情况进行分析。结果14株流感病毒的HA和NA基因在系统发育树上均聚成4个类群,进化分类基本一致。本地毒株HA、NA基因与2019-2020年疫苗毒株A/Kansas/14/2017同源性较低。与A/Kansas/14/2017相比,14个毒株HA基因449位点发生突变,导致糖基化位点的减少,1个毒株在142位点增加一个糖基化位点;NA基因无糖基化位点的变化。相对于A/Kansas/14/2017,南宁毒株HA1区蛋白分子上有6(135、137、144、159、160和190)个的氨基酸发生了替换,且涉及到2~3个抗原决定簇位点;受体结合位点突变主要集中在2个位点;NA基因有1个抗原位点整体发生突变,耐药位点非常保守。结论南宁市2019年H3N2亚型流感病毒在流行过程中相对2019-2020疫苗株发生了一定的变异,其匹配度低于2018-2019及2020-2021年疫苗毒株,尤其是HA的变异可能导致疫苗对本地区人群保护作用降低,导致流感流行。Objective To analyze the prevalence and characteristics of the HA&NA genes of seasonal influenza A(H3 N2)viruses in the City of Nanning in 2019 and to ascertain their spread and evolutionary direction in order to provide a scientific basis for influenza treatment and selection of vaccine strains.Methods The full-length nucleotide sequences of the HA and NA genes of A(H3 N2)influenza viruses prevalent in Nanning in 2019 were obtained from the Global Initiative on Sharing Avian Influenza Data(GISAID)database.A phylogenetic tree was constructed using Mega v7.0 and Interactive Tree of Life V5(iTOLV5).Glycosylation sites were predicted using the software NetN Glycine 1.0,and the homology and amino acid variation of HA and NA were analyzed using the software DNAStar v8.1.3.Results The HA and NA genes of 14 strains were clustered into 4 groups,and the evolutionary classification was basically the same.The HA and NA genes of the local strain had the least similarity to vaccine strain A/Kansas/14/2017 from 2019 to 2020.Compared to A/Kansas/14/2017,the HA gene in 14 strains was mutated at site 449 e,resulting in a reduction in glycosylation sites,and 1 strain had an addition of a glycosylation site at site 142.There were no changes in glycosylation sites in the NA gene.Compared to A/Kansas/14/2017,6 amino acids(135,137,144,159,160,and 190)were substituted in the HA1 region of the Nanning virus,and 2-3 antigen sites were involved;a mutation in a receptor binding site mainly occurred at 2 sites.Overall,1 antigen site of the NA gene had mutated,but its drug resistance sites were highly conserved.Conclusion The A(H3 N2)influenza virus prevalent in Nanning in 2019 varied to an extent compared to the vaccine strains in 2019-2020,and it was less concordant with vaccine strains in 2018-2019 and 2020-2021.Variation in HA in particular may lead to a decrease in the protective effect of vaccines in the local population and the spread of influenza.

关 键 词：H3N2亚型流感病毒 流行分析 HA和NA基因 特性分析 

分 类 号：R373.13[医药卫生—病原生物学]