2013年云南省禽流感病毒H9N2亚型监测及其血凝素基因序列分析  

Surveillance and sequencing analysis of hemagglutinin gene of H9N2 subtype avian influenza virus from Yunnan province in 2013

作　　者：胡媛媛[1] 张文东[2] 宋建领[3] 刘庆亮[4] 曾伟[4] 王锐[1] 郑锦玲[1] 彭洁[1] 保志鹏[1] 张应国[2] 范泉水[5] 赵焕云[2] 张富强[5] 

机构地区：[1]云南农业职业技术学院,云南昆明650031 [2]云南省动物疫病预防控制中心,云南昆明650051 [3]云南省热带亚热带动物病毒病重点实验室,云南昆明650224 [4]云南农业大学,云南昆明650223 [5]成都军区疾病预防控制中心,四川成都100021

出　　处：《中国预防兽医学报》2015年第1期10-14,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：云南省科技计划项目(2012CH002);国家公益性行业专项(201103008);军队科技计划项目(CWS12J075;13BJYZ37;A12005);云南省教育厅科学研究基金项目

摘　　要：为了解H9N2亚型禽流感病毒（AⅣ）的变异情况,本研究对2013年云南省16个地区的3 622份家禽临床样品进行AⅣ的鸡胚分离和RT-PCR检测,其中分离鉴定到97份H9N2亚型AⅣ分离株,并选取21个分离株进行HA基因测序及系统进化分析,结果表明：21份H9N2亚型AⅣ分离株的HA基因核苷酸序列同源性为86.0 ％～99.4％,均属于欧亚分支的类A/Chicken/BeiJing/1/1994亚分支,而且又进一步划分为Ⅲ-1、Ⅲ-2两个小分支.其中Ⅲ-2分支为云南地区新出现的进化分支.氨基酸比对分析显示,测序的21个HA基因编码蛋白的裂解位点基序均具有低致病性病毒分子特征;与现用疫苗株相比,HA推导氨基酸序列中存在多个氨基酸位点差异;其中,Ⅲ-1与Ⅲ-2分支的AⅣ的HA氨基酸序列多个位点存在各自特有的点突变（氨基酸替换）,这种变异具有一定的进化（亚）分支特异性.此外,HA基因多个受体结合位点氨基酸存在变异,其中234位氨基酸全部变为L,呈现了人流感受体结合特性;部分糖基化位点、抗原表位关键性氨基酸也存在变异.A total of 3,622 throat swab samples were collected from 16 different areas of Yunnan province in 2013, and detected by RT-PCR for surveillance of H9N2 subtype avian influenza virus （AIV）, of which 97 samples were positive for H9N2 subtype AIV. In addition, the 21 selected representative isolates were purified by chicken embryonic eggs and the HA genes weresequenced. The results of sequence alignment showed that the homology of these HA genes were from 86.0% to 99.4%, belong to the A/Chicken/BeiJing/1/1994 phylogenetical lineage, which were further divided into 2 subgroup （Ⅲ-1 and Ⅲ-2）, the clade Ⅲ-2 was the new emerged clade in Yunnan area. The HA cleavage site of these isolates belonged to the low pathogenicity. The HA proteins between the isolates of Ⅲ-1 and Ⅲ-2 subgroup had some unique point mutations, which had the evolution （sub） branch specificity. Furthermore, some mutations in HA were found comparing with H9N2 subtype vaccine strain. While, the point mutations of HA existed in the receptor-binding sites, especially at aa234 mutated to L in all the 21 isolates, showing a receptor- binding characteristics of human influenza virus, and partal glycosylation sites and antigenic epitope sites also existed some mutations in the HA proteins.

关 键 词：禽流感监测 H9N2亚型 血凝素 序列分析 

分 类 号：S852.65[农业科学—基础兽医学]