一株GⅠ-19基因型禽传染性支气管炎病毒基因序列分析及致病性研究  

Gene Sequence Analysis and Pathogenicity of a Strain of GⅠ-19 Genotype Avian Infectious Bronchitis Virus

作　　者：武奇 徐梦成 魏邓乐 张雪花[1,2,3] 李丁 梅梅 WU Qi;XU Mengcheng;WEI Dengle;ZHANG Xuehua;LI Ding;MEI Mei(Institute of Veterinary Immunology&Engineering,Jiangsu Academy of Agricultural Sciences,Nanjing,Jiangsu 210014;National Veterinary Biological Products Engineering Technology Research Center,Nanjing,Jiangsu 210014;GuoTai(Taizhou)Center of Technology Innovation for Veterinary Biologicals,Taizhou,Jiangsu 225300;Key Laboratory for Avian Preventive Medicine,Ministry of Education,College of Veterinary Medicine,Yangzhou University,Yangzhou,Jiangsu 225009)

机构地区：[1]江苏省农业科学院动物免疫工程研究所,江苏南京210014 [2]国家兽用生物制品工程技术研究中心,江苏南京210014 [3]兽用生物制品(泰州)国泰技术创新中心,江苏泰州225300 [4]扬州大学兽医学院教育部禽类预防医学重点实验室,江苏扬州225009

出　　处：《中国家禽》2024年第9期94-102,共9页China Poultry

基　　金：国家自然科学基金项目(32202797);江苏省自然科学基金项目(BK20220745);江苏省农业自主创新项目(CX(22)3026)。

摘　　要：为了解传染性支气管炎病毒(IBV)的遗传变异及致病性,试验对江苏某鸡场发病鸡进行病原分离和鉴定,并对分离株S1基因进行同源性、遗传进化树、糖基化位点、S蛋白裂解位点和致病性分析。结果显示:从发病鸡肾脏组织中分离并鉴定到1株IBV,该分离株经SPF鸡胚盲传5代后,可引起典型的侏儒胚特征病变,其S1基因大小为1620 bp,分离株被命名为CK/CH/WJ215;CK/CH/WJ215与GⅠ-19基因型毒株S1核苷酸序列相似性为94.3%,与流行优势基因型GⅠ-19属于同一分支;RDP4重组分析显示该分离株S1蛋白不存在重组事件;进一步糖基化位点分析表明,与常用疫苗株相比,CK/CH/WJ215 S1蛋白在第51、77、103、138、163、178、247、276、283、530位点出现变异,值得注意的是,与H120疫苗株和QXL87疫苗株相比,CK/CH/WJ215 S1蛋白分别在138和530位出现了新的糖基化位点;7日龄SPF鸡致病性试验显示,该分离株可导致SPF鸡100%(15/15)发病,66.7%(10/15)死亡,并且导致严重的肾脏病变;感染鸡从第2天开始持续排毒,直到第21天气管和泄殖腔排毒率仍为80%(4/5)和100%(5/5)。研究表明,从江苏某鸡场发病鸡群种分离的GⅠ-19基因型IBV对SPF雏鸡具有很强的致病性,结果为该地区传染性支气管炎流行病学及防控提供参考。In order to understand the genetic variation and pathogenicity of infectious bronchitis virus(IBV),the pathogen was isolated and identified in infected chickens from a chicken farm in Jiangsu province.The S1 gene homology,phylogenetic tree,poten⁃tial glycosylation sites,proteolytic cleavage sites and pathogenicity analysis of the isolate were carried out.The results showed that a strain of IBV was isolated and identified from the kidney tissue of disease chickens.After 5 generations of blind transmission in SPF chicken embryos,the isolate could cause typical dwarf embryo characteristic lesions with 1620 bp of S1 gene,which was named CK/CH/WJ215.Then,the nucleotide sequence homology between CK/CH/WJ215 and GⅠ-19 genotype strain was 94.3%,and CK/CH/WJ215 and the GⅠ-19 genotype belonged to the same branch.The RDP4 recombination analysis results indicated that the S1 pro⁃tein of the isolate did not undergo any recombination events.Further analysis of glycosylation sites showed the CK/CH/WJ215 S1 protein varied at sites 51,77,103,138,163,178,247,276,283 and 530 compared to common vaccination strains.Interestingly,when the isolate protein was compared to H120 and QXL87 vaccine strains,it revealed novel glycosylation sites at sites 138 and 530,respectively.Furthermore,pathogenicity tests performed on SPF chickens at 7 days of age revealed that the isolates were capable of inflicting significant kidney lesions and 100%(15/15)morbidity,as well as 66.7%(10/15)mortality in SPF chickens.Notably,the vi⁃rus excretion experiment indicated that the virus-shedding from infected chickens started 2 until 21 days post inculation.The virus detection rates in trachea and cloaca were 80%(4/5)and 100%(5/5),respectively.In summary,a strain of GⅠ-19 genotype IBV iso⁃lated in Jiangsu province was highly pathogenic to SPF chicks,which provided a theoretical basis and reference for epidemiology,prevention and control of infectious bronchitis in this region.

关 键 词：传染性支气管炎病毒 GⅠ-19基因型 S1基因 致病性 

分 类 号：S855.3[农业科学—临床兽医学]