芜湖市首例人感染A(H7N9)禽流感病毒基因组特征  

Genomic characterization of the first human infection caused by avian influenza A(H7N9)virus in Wuhu city

作　　者：王共飞[1] 王毅[1] 何军[2] Wang Gongfei;Wang Yi;He Jun(Wuhu Center for Disease Control and Prevention,Wuhu 241000,China;Anhui Provincial Center for Disease Control and Prevention,Hefei 230601,China)

机构地区：[1]芜湖市疾病预防控制中心,241000 [2]安徽省疾病预防控制中心,合肥230601

出　　处：《中华实验和临床病毒学杂志》2020年第5期551-555,共5页Chinese Journal of Experimental and Clinical Virology

摘　　要：目的分析芜湖市2014年首例人感染A(H7N9)禽流感病毒基因组特征。方法患者标本经Real-time RT-PCR检测A(H7N9)核酸阳性后送检中国国家流感中心分离毒株并进行全基因组测序,序列提交GenBank并Blast。运用生物信息学软件DNAStar Lasergene 7.1和MEGA7.0对该病毒基因组进行同源性、关键氨基酸位点突变及系统进化树分析。结果毒株命名为A/Wuhu/1/2014(H7N9),血凝素(hemagglutinin,HA)系统进化树分析属于W2-4分支,HA裂解位点为PEIPKGR↓G,对比高致病性疫苗株A/Guangdong/17SF003/2016(H7N9)缺失4个氨基酸KRTA插入序列。HA受体结合位点发生T160A、G186V和Q226L突变。神经氨酸酶(neuraminidase,NA)茎区69~73位缺失5个氨基酸QISNT。PB2出现L89V、M535L及E627K突变。PB1 I368V,PA V100A、K356R和S409N,NS1 P42S和N205S,NS2 T48A,M1 N30D和T215A均发生了位点突变。NA未发生E119V、R152K、H274Y和R292K突变,但M2出现了S31N突变。结论A/Wuhu/1/2014(H7N9)毒株来源为禽类,起源于长江三角洲地区,对人类受体有亲和力、不耐NA抑制剂、耐M2离子通道抑制剂以及对哺乳动物毒力和人类的适应性增强,属于低致病性A(H7N9)禽流感病毒。Objective To analyze the viral genome characteristics of the first human influenza A(H7N9)infection in Wuhu city in 2014.Methods Samples from a patient diagnosed as positive for the influenza virus A(H7N9)nucleic acid(detected by real-time RT-PCR)were sent to Chinese National Influenza Center for the isolation of strains and genome-wide sequencing.The sequences were submitted to GenBank and Blast was run.Analysis of the homology,key amino acid site mutations and phylogenetic tree of the viral genome were performed with the use of bioinformatics applications,DNAStar Lasergene 7.1 and MEGA7.0.Results The strain was named A/Wuhu/1/2014(H7N9).Phylogenetic tree analysis of hemagglutinin(HA)showed that the strain belonged to clade W2-4.The cleavage site of HA was PEIPKGR↓G.Compared with the highly pathogenic vaccine strain A/Guangdong/17SF003/2016(H7N9),it lacks 4 amino acid KRTA insertion sequences.T160A,G186V and Q226L mutations occurred in the HA receptor binding site.Five QISNT amino acids(position 69-73)were deleted in the neuraminidase(NA)stalk region.L89V,M535L and E627K mutations were found in PB2.Site mutations occurred in PB1 I368V,PA V100A,K356R and S409N,NS1 P42S and N205S,NS2 T48A,M1 N30D and T215A.The E119V,R152K,H274Y,and R292K mutations were not found in NA,while the S31N mutation appeared in M2.Conclusions The A/Wuhu/1/2014(H7N9)strain is derived from poultry and originated in the Yangtze River Delta.The virus has an affinity to human receptors and belongs to the low pathogenic avian influenza A(H7N9)viruses(LPAI H7N9).It is sensitive to NA inhibitors and resistant to M2 ion channel inhibitors.The strain has increased virulence in mammals and enhanced adaptability for humans.

关 键 词：低致病性禽流感病毒 A(H7N9) 基因组 系统进化分析 氨基酸突变 

分 类 号：R511.7[医药卫生—内科学] R440[医药卫生—临床医学]