【摘要】 本试验利用鸡传染性法氏囊病超强毒Gx及其致弱疫苗毒Gt为对象,研究超强毒与弱毒株在鸡体主要免疫器官内的复制情况,以探讨两类毒株表现不同生物特性的原因。分别利用鸡胚半数致死量和鸡胚成纤维细胞半数感染量对超强毒Gx和疫苗株Gt进行病毒滴度的测定;再利用荧光定量RT-PCR对两类毒株进行病毒量的校准。以相同量的病毒对2周龄SPF鸡进行攻毒。攻毒试验表明超强毒Gx能造成47.5%的死亡,法氏囊、脾脏、胸腺等免疫器官均严重损伤;而疫苗毒Gt无致死,且未能造成任何病理可见的损伤。病毒的体内复制情况表明超强毒相对于疫苗毒复制更为迅速,病毒载量更高。更多还原

【Abstract】 To study biological characteristics of infectious bursal disease viruses,the very virulent infectious bursal disease virus (vvIBDV) Gx and vaccine strain Gt were used to compare the replication property in main immune organs of specific-pathogen-free (SPF) chicken. The titer of Gx was measured by 50% chicken embryo lethal dose (ELD50) and the titer of Gt was measured by 50% tissue culture infectious dose (TCID50). The viral loads of Gx and Gt were detected by realtime RT-PCR. Two-week-old SPF chickens were challenged by the same dose of Gx or Gt. The results of virus challenge assay showed that the mortality of Gx was 47.5%,and bursa,spleen and thymus were damaged severely in Gx challenge group. No deaths or any histopathological changes were observed in Gt group. The data of viral replication of Gx and Gt indicated that Gx replicated faster than Gt in vivo,and higher load of virus was detected in bursa of Gx than that of Gt.更多还原