济宁市2017-2020年流感流行季甲型H3N2流感病毒血凝素和神经氨酸酶基因特征  

Genetic characteristics of hemagglutinin and neuraminidase genes of influenza A(H3N2) viruses circulating in Jining city during the 2017-2020 influenza seasons

作　　者：韩淑琪 王胜男 王玉宁[1] 江亚娟 焦伯延[1] Han Shuqi;Wang Shengnan;Wang Yuning;Jiang Yajuan;Jiao Boyan(Jining Municipal Center for Disease Control and Prevention,Jining 272000,Shandong,China)

机构地区：[1]济宁市疾病预防控制中心,山东济宁272000

出　　处：《中国疫苗和免疫》2022年第3期303-308,共6页Chinese Journal of Vaccines and Immunization

基　　金：山东省医药卫生科技发展计划项目(202112060725);济宁市重点计划研发项目[医学研究和临床医学类(2021018)]。

摘　　要：目的了解济宁市甲型H3N2流感病毒流行株血凝素(HA)和神经氨酸酶(NA)基因特征。方法于2017-2020年流感流行季在济宁市2家流感监测哨点医院和流感聚集疫情中选取流感样疾病(ILI)病例咽拭子标本中分离获得的19株甲型H3N2流感病毒,分析HA和NA基因序列同源性、HA基因进化特征、HA和NA基因位点的氨基酸差异。结果济宁市2017-2020年流感流行季ILI病例中甲型H3N2流感病毒检测阳性率为4.77%(218/4575),检测阳性数占流感病毒检测总阳性数的25.89%(218/842)。19株甲型H3N2流感病毒之间HA和NA氨基酸同源性分别为97.7%-100%和98.6%-99.5%,平均遗传距离分别为0.009和0.008。HA基因进化树显示,19株分离株均属3C.2a1b分支,与疫苗代表株A/Kansas/14/2017的亲缘性较远。与该疫苗代表株相比,分离株HA的33个位点存在氨基酸差异,包括10个抗原表位位点、4个受体结合位点、3个糖基化位点、1个潜在类泛素蛋白修饰分子化修饰位点和1个潜在泛素化修饰位点;NA的27个位点存在氨基酸差异,但NA的酶活性催化位点、耐药位点和糖基化位点均无氨基酸差异。结论济宁市2017-2020年流感流行季甲型H3N2流感病毒可能发生了抗原漂移;需加强甲型H3N2流感监测,为疫苗株筛选提供依据。ObjectiveTo explore genetic characteristics of hemagglutinin(HA) and neuraminidase(NA)genes of influenza A( H3N2) viruses circulating in Jining city.MethodsWe selected 19 influenza A(H3N2) virus strains isolated from influenza-like illness(ILI) cases from 2 monitoring settings and/or influenza clusters during the 2017-2020 influenza seasons in Jining. We analyzed homologies of nucleotide and amino acid sequences of HA and NA genes, phylogenetic characteristics of HA gene, and amino acid variations of HA and NA gene loci.ResultsThe positivity rate of influenza A(H3N2) virus was 4. 77%(218/4 575) among ILI cases during the 2017-2020 seasons in Jining;influenza A(H3N2)virus isolates accounted for 25. 89%(218/842) of all influenza virus isolates. Among the 19 influenza A(H3N2) virus isolates, homologies of amino acid sequences of HA and NA genes were 97. 7%-100%and 98. 6%-99. 5%, respectively, with genetic distances of 0. 009 and 0. 008. Phylogenetic analysis of HA genes showed that the 19 isolates belonged to 3C. 2a1b clade, far from the vaccine strain A/Kansas/14/2017. Compared with the vaccine strain, the isolates had amino acid variations at 33 HA gene loci(including 10 epitope sites, 4 receptor binding sites, 3 glycosylation sites, 1 potential small ubiquitinlike modifier site, and 1 potential ubiquitin modifier site), and 27 NA gene loci. No amino acid variations occurred at enzyme activity catalytic site, drug resistance site, and glycosylation site of NA genes.ConclusionsAntigenic drift of influenza A( H3N2) viruses occurred during the 2017-2020seasons in Jining. We should strengthen monitoring A(H3N2) influenza to provide supports for vaccine strain selection.

关 键 词：甲型H3N2流感病毒 血凝素 神经氨酸酶 抗原漂移 基因特征 

分 类 号：R373.1[医药卫生—病原生物学]