2022—2023年新疆甲型H3N2流感病毒血凝素和神经氨酸酶基因特征分析

Characterization of hemagglutinin gene and neuraminidase gene of influenza A(H3N2)virus in Xinjiang,2022-2023

目的分析新疆2022—2023年甲型H3N2流感病毒血凝素(hemagglutinin,HA)和神经氨酸酶(neuraminidase,NA)基因进化特征,为流感防控提供科学依据。方法从新疆15家国家级流感监测网络实验室分离上送的甲型H3N2流感毒株中随机选取15株,用二代测序技术进行HA和NA基因组序列测定,用Mega X和BioEdit软件进行基因序列特征及同源性分析。结果15株甲型H3N2流感病毒HA和NA基因序列与世界卫生组织推荐疫苗株A/Darwin/9/2021相比,核苷酸同源性为98.2%~98.4%、99.3%~99.4%,氨基酸同源性为97.8%~98.0%、99.3%~99.5%;系统进化树分析表明,甲型H3N2流感毒株与疫苗株有较高的亲缘关系,共同归属于3C.2al分支。所有分离株HA基因共涉及8个氨基酸突变位点,仅I156K(15/15)涉及HA蛋白的B区,N138D(12/15)发生在受体结合位点130环,其余6个均为非关键位点的改变;NA基因共发生3个氨基酸位点突变,但均不属于已报道的与耐药相关的关键性突变位点。结论2022—2023年新疆甲型H3N2流感病毒株的HA和NA基因与世界卫生组织当年推荐的疫苗株亲缘关系较近,未出现抗原漂移和耐药毒株。

Objective To analyze the genetic characteristics of hemagglutinin(HA)gene and neuraminidase(NA)gene of influenza A(H3N2)virus in Xinjiang from 2022 to 2023,to provide scientific basis for influenza prevention and control.Methods A total of 15 strains of influenza A(H3N2)virus were randomly selected from 15 influenza surveillance network laboratories in Xinjiang,HA and NA genes sequencing were determined by second-generation sequencing technology.Mega X and BioEdit softwares were used for gene sequence characterization and homology analysis.Results The nucleotide homology of HA gene and NA gene of H3N2 influenza virus isolates were 98.2%-98.4%and 99.3%-99.4%,the amino acid homology was 97.8%-98.0%and 99.3%-99.5%compared with that of the vaccine strain A/Darwin/9/2021 which World Health Organization recommended.The phylogenetic tree showed that 15 influenza H3N2 virus strains were closely related to the vaccine strain and belonged to the 3C.2al branch.The HA gene in all isolates involved 8 amino acid mutation sites,only I156K(15/15)involved the B region of HA protein,N138D(12/15)occurred in the 130 ring of receptor binding site,and the other 6 were non-critical site changes.There were 3 amino acid mutation sites in NA gene,none of which was reported to be the key mutation sites related to drug resistance.Conclusion The HA gene and NA gene of the H3N2 influenza virus strains in Xinjiang,2022-2023 were closely related to World Health Organization recommended vaccine strain in that year,and no antigenic drift and drug-resistant strains appeared.