江苏省首例人感染H9N2禽流感病毒分子溯源研究  

Genetic origin of human infection with avian influenza A H9N2 virus in Jiangsu province

作　　者：邓斐[1] 祁贤[1] 余慧燕[1] 王慎骄[1] 许可[1] 黄昊頔 鲍倡俊[1] DENG Fei;QI Xian;YU Hui-yan;WANG Shen-jiao;XU Ke;HUANG Hao-di;BAO Chang-jun(Jiangsu Provincial Center for Disease Control and Prevention,Nanjing 210009,Jiangsu,China)

机构地区：[1]江苏省疾病预防控制中心,南京210009

出　　处：《医学研究生学报》2021年第10期1057-1061,共5页Journal of Medical Postgraduates

基　　金：江苏省重大科技示范项目(BE2017749);江苏省医学重点学科(ZDXKA2016008)。

摘　　要：目的近年来,H9N2亚型禽流感对人类健康的危害越来越受到关注。文中旨在对1例人感染H9N2禽流感病毒进行分子溯源研究。方法选取2019年3月18日江苏省疾病预防控制中心1份禽流感病毒感染患者的咽拭子标本及从患者住处附近的农贸市场采集禽类和外环境样本共40份。标本的流感病毒分型检测采用荧光定量PCR法,病毒分离采用SPF鸡胚,用特异性引物对病毒分离物进行全基因组测序,利用Blasts、ClustalX和Mega 6.1等软件进行序列比对和系统进化分析。结果标本中的病毒为A型H9N2亚型流感病毒。分子进化分析表明,4株病毒的HA和NA都属于H9N2禽流感Y280-like基因型。HA和NA进化树显示,人分离株和3株农贸市场分离病毒同处于一个进化分支上,遗传关系较近。HA蛋白的受体结合位点有4个氨基酸位点(包括I155T、H183N、A190T/V和Q226L)发生突变,增强了病毒对人类SAα2-6Gal受体的结合力。NA蛋白274(H→Y)位点没有发生突变。结论江苏省首例人感染H9N2禽流感病毒属于Y280-like基因型,对人类SAα2-6Gal受体的亲和力增加,跨种传播感染人的能力增强,病毒的进化值得关注。Objective To isolate and perform the gene characteristics of a H9N2 avian influenza virus from a human case.Methods Specimens were detected by real-time quantitative PCR method.Whole-genome sequences of original specimen and virus isolates were obtained by next-generation sequencing technology.Pairwise sequence alignments and phylogenetic analysis were performed by Blasts,ClustalX and Mega 6.1 softwares.Results In March 2019,a human case infected with avian influenza A H9N2 virus was confirmed.Eight H9N2 viruses were isolated from the live poultry market.Molecular evolution analysis showed that HA and Na of the four strains belonged to H9N2 avian influenza Y280-like genotype.The cleavage site of HA protein of four H9N2 strains contained one basic amino acid R,which belonged to low pathogenic avian influenza virus.Four amino acid sites(including I155T,H183N,A190T/V and Q226L)were mutated in the receptor binding sites of HA protein,which indicated that these viruses enhanced the binding capacity to human SAα2-6gal receptor.Conclusion A human case infected with a Y280-like genotype of H9N2 avian influenza virus is determined,suggesting that the surveillance of avian influenza virus and the study of cross species transmission should be strengthened.

关 键 词：禽流感病毒 H9N2亚型 Y280-like基因型 跨种传播 

分 类 号：R511[医药卫生—内科学]