连云港地区2018年甲型H1N1流感病毒NA基因特征

Phylogenetic analysis of influenza A (H1N1) virus isolated in Lianyungang in 2018

目的了解连云港地区2018年甲型H1N1流感病毒神经氨酸酶(NA)基因突变及抗原变异情况。方法随机提取2018年春季连云港地区分离的3株甲型H1N1流感病毒株,用RT-PCR方法对NA基因进行扩增,利用生物软件对基因序列特征及变化情况进行分析。结果 3株甲型H1N1流感病毒株的NA基因与流感疫苗株A/California/07/2009(H1N1)比对,NA区20个氨基酸位点发生变异,根据NA基因进化树分析发现,3株甲型H1N1流感毒株在同一分支上,与2017年分离到的甲型H1N1流感毒株亲缘关系近,与疫苗株A/Califonia/07/2009(H1N1)亲缘关系远。结论 2018年春季连云港地区的流感流行株相对于国际疫苗株已经出现抗原改变,对本地区流感防控工作带来更大挑战。

Objective To understand genetic mutation in NA of influenza A(H1 N1) viruses isolated in Lianyungang in 2018. Methods Three strains of H1 N1 influenza virus isolated in Lianyungang in 2018 were randomly selected. The NA gene sequence was amplified by RT-PCR and the sequence characteristics and changes were analyzed by using biological software. Results The NA gene of 3 strains of H1 N1 influenza virus were compared with the influenza vaccine strain A/California/07/2009(H1 N1). 20 amino acid residues in NA region were replaced. The phylogenetic tree of NA gene showed that 3 strains of H1 N1 were on the same branch and were closely related to H1 N1 influenza viruses isolated in 2017, and more distantly related to the vaccine strain A/California/07/2009(H1 N1). Conclusion In 2018, the influenza A(H1 N1) virus prevalent in Lianyungang have antigenic drift compared with international vaccine strains, and it′s greater challenges to influenza prevention and control.