鸡肾型传染性支气管炎病毒的分离及鉴定

Isolation of Nephrotropic Avian Infectious bronchitis Virus and Identification of Its Biological property

本试验从天津某鸡场、呼和浩特市两个鸡场发病鸡群分离到３个肾型ＩＢＶ毒株，分别命名为Ｔ、Ｈ、Ｗ株，并对其培养特性、形态特性、血凝性、致病性、对新城疫病毒的干扰性等方面进行研究。结果表明，３个毒株很快适应于鸡胚，引起鸡胚出血、萎缩、绒毛尿囊膜增厚；３个毒株也适应于鸡胚肾、肺细胞，适应性有差异；病毒增殖后制负染样品，在电镜下观察，可看到直径约１００ｎｍ左右，病毒囊膜外有疏松刺突的冠状病毒。用接毒的肾、肺细胞制成超薄切片后电镜下观察，可看到胞浆内的典型的ＩＢＶ；分离株对鸡的红细胞无凝集性，但用１％胰酶处理后表现不同程度的血凝性；３个分离株均能抑制鸡新城疫病毒Ｂ＿１株在鸡胚中繁殖；分离株回归４２日龄雏鸡后从第３天开始发病，发病率为１００％，病死率为６０－９０％。

Three strains of nephrotropic avian infectious bronchitis(IB) virus , named T,H,and Wstrains,respectively, were isolated from the kidneys of sick chickens from one farm in TianJin. and twofarms in Huhhot.Culture, hemagglutination, pathogenicity and NDV interference trials were carried out. The results indicated that the three isolated strains could rapidly adapte to chicken embryos, causing chickenembryo hemorrhage,atrophy and chorionic thickening. They also adapted to chicken embryo kidney cells(CK) and lung cells(CL), but there were differences in their adaptability. Undder the electron microscope,the virion was a coronavirus, 100nm in diameter and had sparse projections on the envelope in the negativestained sample prepared from propagated virus. There was typical IBV intracellular in the ultrathin sectionsprepared from inoculated CK and CL. The isolates lacked the ability to agglutinate chicken erythrocytes,butshowed hemgglutination to different degrees after treatment with 1%trypsin, Three strains could inhibitNDV-B_1strain propagation in chicken embryos. Forty-two days-old chickens Inoculated with the strains,showed clinical signs of IB at three days postinoculation.The morbidity rate was 100%and the mortality ratewas 60-90%。