三株传染性法氏囊病病毒重组毒株的致病性研究  

Pathogenicity of Three Recombinant Strains of Infectious Bursal Disease Virus

作　　者：杨坤 马静文 周新瑞 罗烈柱 刘喆 胡自强 武星辰 梁立滨 高诗敏 YANG Kun;MA Jingwen;ZHOU Xinrui;LUO Liezhu;LIU Zhe;HU Ziqiang;WU Xingchen;LIANG Libin;GAO Shimin(College of Veterinary Medicine,Shanxi Agricultural University,Taigu 030801,China)

机构地区：[1]山西农业大学动物医学学院,太谷030801

出　　处：《畜牧兽医学报》2024年第6期2550-2559,共10页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：山西省高等学校科技创新项目(2019L0371)。

摘　　要：鸡传染性法氏囊病(IBD)是由传染性法氏囊病毒(IBDV)引起雏鸡发病的一种高致病性免疫抑制性疾病,目前IBDV重组变异株性对鸡养殖业有严重危害。本研究对三株IBDV重组毒株进行全基因序列分析并测定其致病性差异。通过鸡胚分离鉴定并增殖三株IBDV毒株,利用Mega 11、MegAlign软件与参考毒株进行核苷酸同源性比对和氨基酸进化树绘制,将病原感染SPF鸡测定致病性,用实时荧光定量PCR方法检测脏器病毒拷贝量,结果显示:GD-1株属于A2dB3型,呈现新型变异A超强B特点,GD-2株和GD-3株同属于A3B1型,分别呈现超强A新型变异B和超强A早期变异B特点;三株病毒均未引起雏鸡死亡,GD-1株无明显临床症状,GD-2株和GD-3株在攻毒后7 d出现精神沉郁,卧地不起;引起其法氏囊显著萎缩、脾肿大,法氏囊载毒量要高于脾载毒量,在攻毒后第14天时GD-1株的法氏囊载毒量显著高于GD-2株和GD-3株;三组试验鸡法氏囊滤泡均发生萎缩,且GD-2组和GD-3组病变更严重,脾则是GD-1组病变更严重。本研究测定三株IBDV的序列、绘制进化树,测定致病性,显示三株病毒都有新型变异株的变异趋势,为研究IBDV致病机理和防控IBD提供参考。Infectious bursal disease is a highly contagious,immunosuppressive disease of young chickens caused by infectious bursal disease virus(IBDV).In recent years,recombinant IBDV mainly threats to the poultry industry.In our study,we characterized whole-gene sequence analysis of three recombinant strains of infectious bursal disease virus and assessed its pathogenicity in specific pathogen-free chickens.Three strains of virus were identified and amplified by chicken embryo isolation.The nucleotide homology and amino acid evolution tree were compared with the reference strain by Mega 11 and MegAlign software.The pathogen was infected with SPF chickens to determine the pathogenicity,and the viral copies in organs were detected by real-time fluorescence quantitative PCR.Phylogenetic analysis revealed that GD-1 strain belonged to type A2dB3,and showed the characteristics of new variant A,very virulent B;Strain GD-2 and strain GD-3 belong to type A3B1,showed the characteristics of very virulent A,new variant B and very virulent A,early variant B.Pathogenicity assays showed that none of the three strains caused the death of chicks,GD-1 strain had no obvious clinical symptoms,and GD-2 strain and GD-3 strain showed depression and lying on the ground 7 days after the attack.It caused significant atrophy of bursa of Fabricius and enlargement of spleen.The load of toxin in bursa of Fabricius was higher than that in spleen.On the day 14 days after challenge,the bursa of bursa of GD-1 strain was significantly higher than that of GD-2 strain and GD-3 strain.Three groups of experimental chickens bursa of fabricius follicles are shrinking,and GD-2 group and GD-3 pathological changes is more serious,the spleen is a GD-1 set of pathological changes is more serious.In this study,the sequence of the three strains was determined,the evolutionary tree was drawn,and the pathogenicity was determined.It may help to study the pathogenic mechanism and the prevention of infectious bursal virus in poultry.

关 键 词：传染性法氏囊病毒 序列分析 重组病毒 致病性 

分 类 号：S852.659.4[农业科学—基础兽医学]