Li B D, He J, Li H Y, Zhang H, Xu C S, Yu D S, Li J B, He J
Gansu Provincial Center for Disease Control and Prevention, Lanzhou 730020, China.
Anhui Provincial Center for Disease Control and Prevention, Hefei 230601, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2020 Aug 10;41(8):1345-1351. doi: 10.3760/cma.j.cn112338-20190712-00518.
To analyze the genomic characteristics of human infection with H9N2 avian influenza virus in Gansu province. The etiological analysis was conducted for human infection with H9N2 avian influenza virus detected in influenza like illness cases in northwestern China in 2016. Molecular bioinformatics Mega 7.0 software was used to analyze the full genomic sequences of the viral isolate. The gene fragments of HA, NA, MP, NP, NS, PA, PB1 and PB2 of the isolate were highly similar (>90%) to those of H9N2 avian influenza virus strain isolated in external environment in Gansu from 2014 to 2019. The HA gene belonged to BJ/94-like branch, PB2 and MP belonged to G1/97-like branch, and the PB1, PA, NS, and NP genes belonged to F/98-like branch. MP and PB2 were closely related to H7N9, H10N8 and H5N6 viruses. Amino acid sequence alignment showed that the HA cleavage site was arranged in PSRSSR ↓ GLF, H183N and Q226L mutated which included 7 HA glycosylated sites; 62-64 sites of NA absented 3 amino acids (ITE); and M2-31N, NS1-42S, PA-356R, and PA-409N mutated. Apparently, this case of human infection with human infection with H9N2 avian influenza virus was an incidental. However, the isolates of H9N2 influenza virus in external environment of Gansu had a series of mammalian adaptive molecular markers, suggesting that the risk of human infection is higher. It is necessary to strengthen the surveillance by multi departments to deal with influenza pandemic.
分析甘肃省人感染H9N2禽流感病毒的基因组特征。对2016年中国西北部流感样病例中检测到的人感染H9N2禽流感病毒进行病原学分析。运用分子生物信息学Mega 7.0软件分析病毒分离株的全基因组序列。该分离株的HA、NA、MP、NP、NS、PA、PB1和PB2基因片段与2014年至2019年甘肃省外部环境中分离的H9N2禽流感病毒株高度相似（>90%）。HA基因属于BJ/94样分支，PB2和MP属于G1/97样分支，PB1、PA、NS和NP基因属于F/98样分支。MP和PB2与H7N9、H10N8和H5N6病毒密切相关。氨基酸序列比对显示，HA裂解位点排列为PSRSSR↓GLF，H183N和Q226L发生突变，其中包括7个HA糖基化位点；NA的62 - 64位点缺失3个氨基酸（ITE）；M2 - 31N、NS1 - 42S、PA - 356R和PA - 409N发生突变。显然，该例人感染H9N2禽流感病毒属于偶发事件。然而，甘肃省外部环境中的H9N2流感病毒分离株具有一系列适应哺乳动物的分子标记，提示人感染风险较高。有必要加强多部门监测以应对流感大流行。
