2022年河南省安阳市甲型H3N2流感病毒基因特征

Genetic characterization of influenza A(H3N2)virus in Anyang City,Henan Province in 2022

目的分析河南省安阳市2022年甲型H3N2流感病毒基因特征,为科学防控流感提供依据。方法利用测序技术对2022年安阳市17株甲型H3N2流感病毒进行全基因组序列测定,运用生物信息学软件对甲型H3N2流感病毒的血凝素(HA)和神经氨酸酶(NA)基因序列进行比对,构建分子进化树,分析基因特征。结果安阳市17株甲型H3N2流感病毒分离株间核苷酸序列的同源性为98.7%~100.0%,氨基酸序列的同源性为98.1%~100.0%;与疫苗株A/Cambodia/e0826360/2020(H3N2)比较,核苷酸序列的同源性为95.7%~99.4%,氨基酸序列的同源性为96.9%~98.6%。17株甲型H3N2流感病毒分离株均属于3C.2a1b.2a.1a.1分支,与疫苗株A/Cambodia/e0826360/2020(H3N2)相比,HA基因共发生16处氨基酸位点变异,但变异位点均没有在HA抗原决定簇和RBS的位置;NA基因共发生13处氨基酸位点变异,与目前已知报道的耐药相关的变异位点不同,HA和NA潜在N-糖基化位点在数量和位置上均发生变化。结论2022年安阳市甲型H3N2流感病毒在流行过程中未发生明显变异;但HA和NA多个氨基酸位点的变异提示仍需加强对甲型H3N2流感病毒分子水平的动态监测。

Objective To analyze the genetic characteristics of influenza A(H3N2)virus in Anyang City,Henan Province in 2022,so as to provide an evidence for scientific prevention and control of influenza.Methods The whole genome sequence of 17 influenza A(H3N2)viruses in Anyang City in 2022 was determined by sequencing technology;HA and NA gene sequences of influenza A(H3N2)viruses were compared by bioinformatics software;the molecular phylogenetic tree was constructed and the genetic characteristics were analyzed.Results The nucleotide homology of the 17 influenza virus isolates in Anyang City was from 98.7%to 100.0%,and the homology of amino acid sequences was from 98.1%to 100.0%.Compared with the vaccine strain A/Cambodia/e0826360/2020(H3N2),the homology of nucleotide sequence was from 95.7%-99.4%,and the homology of amino acid sequence was from 96.9%-98.6%.The 17 influenza A H3N2 virus isolates all belonged to the 3C.2a1b.2a.1a.1 clade,and compared with the vaccine strain A/Cambodia/e0826360/2020(H3N2),there were 16 amino acid site mutations in HA gene,among which none of the amino acid mutation sites were in the HA antigenic determinant cluster and RBS.A total of 13 amino acid sites were mutated in the NA gene,different from the currently reported mutation sites related to drug resistance.The number and location of potential N-glycosylation sites in HA and NA all changed.Conclusions In 2022,the influenza A(H3N2)virus in Anyang City did not mutate significantly during the epidemic.However,the mutation of multiple amino acid sites in HA and NA suggests that dynamic monitoring of influenza A(H3N2)virus at the molecular level still needs to be strengthened.