摘要
目的了解北京市某区1例人感染H7N9禽流感病毒基因特征,为禽流感病例的早期发现、疫情控制提供参考。方法提取病例临床样本病毒核酸,反转录扩增后进行病毒血凝素基因(hemagglutinin, HA)、神经氨酸酶基因(neuraminidase, NA)序列测定。获得的病毒序列与全球流感共享数据库中H7N9禽流感病毒株进行序列分析,比较该病毒与北京市既往发现株和其他省市毒株同源性,构建系统发育树,并对部分耐药位点和糖基化位点进行分析。结果北京市某区1例H7N9禽流感病毒为低致病性禽流感。HA、NA与北京既往发现的29株毒株氨基酸同源性为97.2%~100%和96.8%~100%,基于系统进化分析与之最为相近的疫苗株为A/Hunan/02650/2016。HA蛋白受体结合位点发生了G186V、Q226L突变,HA和NA的糖基化位点均未发生变化。结论该区出现的H7N9病毒与北京地区既往发现H7N9毒株具有高度同源性,部分氨基酸位点存在变异,但未发生耐药突变。
Objective To study the genetic characteristics of avian influenza A(H7 N9)virus from one human infection case in a district of Beijing so as to provide references for early detection of avian influenza cases and control of the epidemic.Methods Nucleic acid of clinical sample of the case was extracted and detected by one-step RT-PCR.After the reverse transcription amplification,the coding regions of hemagglutinin(HA)and neuraminidase(NA)genes were sequenced.The results of sequencing were compared with their corresponding sequence in Global Initiative on Sharing All Influenza Data(GISAID)database,and homology analysis of the virus strain in this district and other ones previously detected in Beijing and other provinces and cities was conducted.A phylogeny tree was constructed.Sequence alignment and homology-modeling methods were used to study specific mutations regarding phenotypes,specifically addressing the human receptor binding properties.Results The results demonstrated that it was a low-pathogenic strain.There were minor differences in HA and NA proteins between 29 human H7 N9 strains previously detected in Beijing and the strain found in this district,with the homology of 97.2%-100%and 96.8%-100%,respectively.The strain was highly homologous to candidate vaccine viruses(A/Hunan/02650/2016)based on phylogenetic analysis.Viral amino acid variation showed that this strain had mutations at 186(G186 V)and 226(Q226 L)sites in HA protein.The HA and NA glycosylation sites were conservative.Conclusions The sequences of H7 N9 virus strain found in this district are highly homologous to those of the virus strains previously detected in Beijing.Though the strains have some significant mutations of amino acid in HA and NA proteins,all isolates show no drug-resistant mutations.
作者
吴杨
牛桓彩
庄鹏
李东迅
刘重程
李飒
舒高林
潘阳
WU Yang;NIU Huan-cai;ZHUANG Peng;LI Dong-xun;LIU Zhong-cheng;LI Sa;SHU Gao-lin;PAN Yang(Changping District Center for Disease Control and Prevention,Beijing 102200,China;Beijing Center for Disease Control and Prevention,Beijing 100013,China)
出处
《实用预防医学》
CAS
2020年第6期667-671,共5页
Practical Preventive Medicine
基金
北京市昌平区卫生科技发展专项(编号:昌卫科2018-2-05)。
关键词
H7N9
禽流感
序列分析
H7N9
avain influenza
sequencing analysis
