甘肃省两例人感染欧亚类禽H1N1猪流感病毒的HA、NA基因特性和抗原性分析

Characteristics of HA,NA genes and antigenicity of two strains of Eurasian avian H1N1 swine influenza virus from two human cases in Gansu province

目的分析甘肃省发现的2例人感染欧亚类禽H1N1猪流感病毒(EAS-H1N1)的抗原性和基因特性,为疾病预防控制提供科学参考。方法对甘肃省2021年2月以来发现的2例人感染EAS-H1N1进行抗原性和基因组对比分析,并使用Mega7.0等软件分析其基因组特征。结果2例人感染EAS-H1N1病例,均有相关环境暴露史,获得2株毒株:A/Gansu-Xifeng/1143/2021和A/Gansu-Xifeng/1194/2021。2株毒株的HA、NA基因均来自欧亚类禽H1N1猪流感病毒,与河北、天津的人感染EAS-H1N1病毒和山东的貂体内分离的EAS-H1N1病毒亲缘关系较近;2株毒株的HA受体结合位点均发生E190D、D225E突变,NA蛋白均未发生H274Y和N294S突变。结论甘肃省人感染EAS-H1N1病毒基因组发生了部分重要分子突变,可能导致其毒力增强,并具备潜在的人际间传播能力。加强EAS-H1N1基因特征研究分析有助于从分子水平上监测病毒变异突变并对疫情进行科学防控。

Objective To analyze the antigenicity and genetic characteristics of two strains of Eurasian avian H1N1 swine influenza virus(EAS-H1N1)isolated from 2 human cases found in Gansu province to provide scientific reference for disease prevention and control.Methods Two cases of human infection with EAS-H1N1 discovered in Gansu province since February 2021 were analyzed for antigenicity and genome comparison,and their genome characteristics were analyzed using software such as Mega7.0.Results Two human infections with EAS-H1N1 had related environmental exposure history.Two strains were obtained:A/Gansu-Xifeng/1143/2021 and A/Gansu-Xifeng/1194/2021.The two strains of HA,NA genes were all from the Eurasian avian H1N1 swine influenza virus,and are closely related to the human infection EAS-H1N1 virus in Hebei and Tianjin and the EAS-H1N1 virus isolated from the mink in Shandong;the HA receptor binding sites of 2 strains E190D and D225E mutations occurred in all spots,and there were no H274Y and N294S mutations in NA protein.Conclusions Some important molecular mutations occurred in the genome of people infected with EAS-H1N1 virus in Gansu province,which may lead to increased virulence and potential human-to-human transmission.Strengthening the research and analysis of EAS-H1N1 gene characteristics will help to monitor the mutation and mutation of the virus at the molecular level and scientifically prevent and control the epidemic.