引起免疫失败的IBV分离株的生物学特性及结构基因分析  

Analysis of Biological Characteristics and Structural Genes of IBV Isolate from Chickens with Immunoprophylaxis Defeat

作　　者：磨美兰[1] 李孟[1] 陈秋英[1] 王秀英[1] 范文胜[1] 韦正吉[1] 韦平[1] 韦天超[1] 

机构地区：[1]广西大学动物科学技术学院,南宁530005

出　　处：《基因组学与应用生物学》2009年第2期275-280,共6页Genomics and Applied Biology

基　　金：国家自然科学基金(30700599);广西自然科学基金(桂科青0728003);广西高等学校优秀人才资助项目(桂教人才0802);硕士研究生科研创新项目(2007105930906M87)资助

摘　　要：本研究应用鸡胚尿囊腔接种的方法,从广西患传染性支气管炎的免疫失败的病鸡中分离到一株传染性支气管炎病毒(IBV)(命名GX-YL5),通过间接血凝试验、动物回归试验和气管环交叉中和试验对该毒株进行鉴定和主要生物学特性的研究,同时利用RT-PCR技术扩增克隆该病毒的S1基因和N基因并测定其核苷酸序列。结果表明:该病毒株有间接血凝性;致病性较强;血清型不同于常用疫苗株H120、Ma5、4/91。同源性分析表明,S1基因核苷酸和氨基酸序列与参考株的同源性分别为63.5%～81.2%和50.7%～78.8%;N基因核苷酸和氨基酸序列与参考株的同源性分别为85.7%～87.2%和89.5%～91.7%;S1基因和N基因系统进化分析表明分离株与其它参考毒株的亲缘关系较远。S1基因和N基因分型与血清学试验结果相吻合。本研究结果提示了广西分离株GX-YL5可能是一个新的变异株,这可能是目前免疫失败的重要因素,同时也为研制适合本地使用的IBV疫苗提供了科学依据和物质基础。Infectious bronchitis virus （IBV）, named GX-YL5, was isolated from flocks with immunoprophylaxis defeat in Guangxi by chick embryo allantoic cavity inoculation. The identification and analysis of important biological characteristics were carried out by indirect hemagglutination test, animal pathogenicity test, chick embryo tracheal organ cultures cross neutralization test. S1 and N gene of GX-YL5 were amplified by RT-PCR technique and the cDNA sequences were determined. The results showed that IBV （GX-YL5）, which was treated, could hemagglutinate chicken red blood cells, have high pathogenicity, and the serotype of GX-YL5 is different from that of three commonly used vaccine viruses H120, Ma5 and 4/91.The identity of the nucleotide sequence and the deduced amino acid sequence of S1 gene between GX-YL5 isolate and other IBV reference strains were from 63.5% to 81.2% and from 50.7% to 78.8%, respectively. The identity of the nucleotide sequence and the deduced amino acid sequence of N gene between GX-YL5 isolate and other IBV reference strains were from 85.7% to 87.2% and from 89.5% to 91.7%, respectively. The results ofphylogenetic analysis of S1 and N gene showed that GX-YL5 have less relation-ship with the reference strains, which agreed with that of serological test. The present study indicated that field isolate GX-YL5 may be a new variant, which was the major reason for the failure of immunological protection. The study provides a reliable scientific basis and substance foundation for developing effective vaccine of IBV in Guangxi.

关 键 词：支气管炎病毒(IBV) 生物学特性 结构基因 克隆 序列分析 

分 类 号：S852.65[农业科学—基础兽医学]