2018-2019年克拉玛依市新甲型H1N1流感病毒NA基因分析

Analysis of NA gene characteristics of new influenza A(H1N1)virus in Karamay city from 2018 to 2019

目的分析新疆克拉玛依市新甲型H1N1流感病毒NA基因特征及变异情况。方法采集2018年1月-2019年12月哨点医院流感样病例咽拭子,经MDCK细胞完成流感病毒分离后,随机抽取26株分离株测定其NA基因序列,并与疫苗株进行序列比对和分析。结果与疫苗株A/Michigan/45/2015 NA基因核苷酸相比,2018年分离株与其同源性为98.56%~99.28%,2019年分离株与其同源性为98.35%~98.71%;26株分离株与同期国内其他地区代表株和疫苗株A/Michigan/45/2015在同一进化分支;分离株T180699较疫苗株A/Michigan/45/2015少1个糖基化位点(42~44位),分离株T190041发生了I223V位点变异。结论相对于疫苗株A/Michigan/45/2015,2018-2019年克拉玛依市新甲型H1N1流感病毒NA基因抗原决定簇、糖基化位点和耐药相关位点已有改变;应继续加强流感监测,密切关注其基因变异情况。

Objective To analyze the NA gene characteristics and variation of new influenza A(H1N1)virus in Karamay,Xinjiang.Methods Throat swabs of influenza-like cases were collected from sentinel hospitals during the period of January2018 and December 2019.After the isolation of influenza virus by MDCK cells,26 strains were randomly selected and their NA gene sequences were determined and conducted sequence alignment and analysis with vaccine strains.Results Compared with the vaccine strain A/Michigan/45/2015,the nucleotide homology and amino acid homology were from98.35%to 99.28%and 97.35%to 99.14%for the isolates in 2018 and 2019,respectively.The 26 strains,vaccine strain A/Michigan/45/2015 and other strains in China in the same period were in the same evolutionary branch.One strain(Laboratory number T180699)was short of one glycosylation site(42-44)in comparison with the vaccine strain A/Michigan/45/2015,and the isolated strain T190041 occurred I223V site mutation.Conclusions The antigenic determinants,glycosylation sites and drug-resistance related sites of the NA gene of the new influenza A(H1N1)changes in Karamay from 2018 to 2019 by comparing with the vaccine strain A/Michigan/45/2015.Surveillance should be reinforced continuously to closely monitor the genetic variation.