传染性法氏囊病病毒超强毒株ZHA001株的分离及鉴定

Isolation and Identification of Very Virulent Infectious Bursal Disease Virus Strain ZHA001

关键词:  传染性法氏囊病病毒 VP2基因 序列分析

Key words:  infectious bursal disease virus  vp2 gene  sequence analysis

摘要:

为探索一个已免疫传染性法氏囊病活疫苗的817肉鸡场在免疫后发生IBD的原因，本研究对病料进行病毒分离，通过RT-PCR扩增分离株VP2基因后进行相关分析，并对分离株的致病性进行测定。结果显示，分离到一株传染性法氏囊病病毒，将其命名为ZHA001株；ZHA001株 VP2 基因序列与参考株的同源性为 90.1%～97.9%，与超强毒株氨基酸序列同源性大于99%；具有超强毒株的特征性氨基酸位点；遗传进化分析发现，ZHA001株属于超强毒株分支；致病性试验中，发病率为100%，致死率为90%。结果表明：IBDV ZHA001株为超强毒病毒。

Abstract:

To investigate the reasons of infectious bursal disease (IBD) infection in the 817 broiler flocks immunized with IBD live vaccine. A IBDV strain designated as ZHA001 was isolated, the vp2 gene was amplified and determined after virus isolation, IBDV isolate was further characterized by the pathogenicity evaluation. The VP2 gene sequence of ZHA001 had 90.1% to 97.9% homology with the reference strains, and the homology of the amino acid sequence was above 99% with the vvIBDV strains, the VP2 amino acid sequence of IBDV ZHA001 strain was consistent with the characteristics of other vvIBDV strains，phylogenetic analysis showed that ZHA001 was belonged to the branch of vvIBDV strains, the mortality of the infected SPF chickens was 90%.The results showed that the ZHA001 isolate was a very virulent IBDV, this study provided a reference for the prevention and control of IBD.