摘要
为研究已免疫传染性法氏囊病(IBD)疫苗的蛋鸡群发生非典型IBD的原因,从2019年检测为传染性法氏囊病病毒(IBDV)阳性的病料中进行病毒分离,并对分离株进行生物学特性测定。结果显示,从5份阳性病料中分离到5株IBDV,5株分离株均不致死SPF鸡,剖检后仅发现法氏囊萎缩,无其它典型病变;对5株分离株VP2基因的遗传进化分析发现,5株IBDV均属于新型变异株分支,而且5株IBDV分离株均具有IBDV变异株的特征性氨基酸位点222T、249K、286I、318D,另外也具有新型变异株的独特氨基酸位点221K、252I和299S;攻毒保护试验表明,使用当前的IBD灭活疫苗对IBDV经典强毒株可提供100%保护,对2019年分离的IBDV流行株保护率为50%~80%。研究提示,IBDV新型变异株已在部分蛋鸡群中流行,而且当前疫苗不能对鸡群提供完全保护,有必要研发用来预防IBDV新型变异株感染的疫苗。
To elucidate the reasons of atypical infectious bursal disease(IBD) infection in the layer flocks immunized with IBD vaccines, virus isolation was performed from infectious bursal disease virus(IBDV) positive materials detected in 2019, and the biological characteristics of isolated strains were carried out. The results showed that five isolated virus strains were all IBDV-positive samples, none of them were lethal to SPF chickens, and no other typical lesions were found except the bursa of Fabricius was atrophy. Phylogenetic analysis of the VP2 gene showed that five isolated virus strains were all belonged to the branch of novel variant strains. Additionally, four typical amino acid sites(222 T, 249 K,286 I, 318 D) of IBDV variant strains and three typical amino acid sites(221 K, 252 I, 299 S) of IBDV novel variant strains were also identified. Furthermore, the immune challenge experiment indicated that the inactivated IBD vaccine could provide complete protection against the classic virulent IBDV, however, the protection ratio were only from 50%to 80% against the epidemic strains. This study showed that the novel variant strains of IBDV were already prevalent in some layer flocks, and the current IBD vaccine does not provided complete protection, therefore, new IBD vaccines for preventing the IBDV novel variant strains infection in layer flocks should be developed as soon as possible.
作者
崔平
牛晓赛
董新荣
李军朝
杨灵芝
朱杰
CUI Ping;NIU Xiaosai;DONG Xinrong;LI Junzhao;YANG Lingzhi;ZHU Jie(Management and Service Center of Animal Husbandry and Veterinary of Binzhou,Binzhou,Shandong 256600;Shandong Binzhou Wohua Biological Engineering Co.,Ltd.,Binzhou,Shandong 256600)
出处
《中国家禽》
北大核心
2020年第9期35-39,共5页
China Poultry
基金
滨州沃华生物基金项目([WH]201901QB01-02)。
关键词
传染性法氏囊病病毒
分离
遗传进化分析
变异株
infectious bursal disease virus
isolation
phylogenetic analysis
variant strain
作者简介
崔平(1979-),女,本科,兽医师,主要从事动物疫病预防控制及畜牧新技术推广工作,E-mail:13954350070@163.com;通讯作者:朱杰(1989-),男,博士,助理研究员,主要从事动物疫病防控技术研究,E-mail:zhujievet@qq.com。
