Two tissue samples were collected from chickens suspected of Newcastle disease in a chicken farm of Urumqi in Xinjiang, and two isolates were obtained by incubating the chicken embryos and unimmunized chickens with the treated tissue samples and then identefied by hemagglutination test,electron microscopy and pathogenicity determination respectively. The results indicated that the two strains could cause typical pathological change of Newcastle disease on chicken embryos and non-immunized chickens. The hemagglutination test showed that two isolates had haemaggluting property and could be inhibited by the positive antiserum of Newcastle disease virus. Electron microscopy result showed that two isolates were of the same size as Newcastle disease virus. Pathogenicity determination indicated that EID50 was 10-8.0/0.1 mL and 10-8.6/0.1 mL respectively,mean death time of chicken embryos(MDT) was 57.6h and 52.8h respectively,the intracerebral pathogenicity index(ICPI)was 1.875 and 1.925 respectively,and the intravenous pathogenicity index(IVPI)was 2.39 and 2.82 respectively. All these results demonstrated that the two isolated strains were high virulent Newcastle disease virus. In addition,Immunogenicity tests showed that two strains had good immunogenicity,and the immune protective rate were 90% and 80% respectively.% 从新疆乌鲁木齐市郊区疑似新城疫的发病鸡场采集了2份病料,处理后接种鸡胚和非免疫鸡分离鉴定病毒,同时检测病毒血凝特性,观察病毒形态并测定病毒致病力.试验结果表明,分离株均能致死鸡胚,非免疫鸡出现典型的鸡新城疫病病理变化；分离毒株均有血凝特性,而且可被新城疫阳性血清所抑制；病毒形态结构与鸡新城疫病毒一致；EID50分别为10-8.0/0.1 mL、10-8.6/0.1 mL,MDT分别为57.6 h、52.8 h,ICPI分别为1.875、1.925,IVPI分别为2.39、2.82,均有很强的致病力,符合NDV强毒株的毒力标准.所有结果显示,以上2个分离株均为新城疫强毒力毒株.病毒免疫原性结果显示,2株病毒均有有良好的免疫原性,同源保护率分别为90%、80%
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