Jiang Nan, Wang Yulong, Zhang Wenying, Niu Xinxin, Gao Yulong, Gao Li, Li Kai, Cui Hongyu, Liu Aijing, Pan Qing, Liu Changjun, Zhang Yanping, Wang Xiaomei, Qi Xiaole
Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150069, PR China; Jiangsu Co-innovation Centre for Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou 225009, PR China.
Virus Res. 2021 Sep;302:198498. doi: 10.1016/j.virusres.2021.198498. Epub 2021 Jul 2.
Infectious bursal disease virus (IBDV), the causative agent of infectious bursal disease (IBD), mainly damages the bursa of Fabricius, which is a central immune organ of birds. As an RNA virus, IBDV is prone to mutation owing to a combination of factors including natural selection pressure. In this study, a naturally occurring mutated IBDV associated with bursa damage was identified, IBDV-HeN20-7103 strain, in an infected chicken flock in central China. Its full-length genome was cloned, and sequence analysis showed that the IBDV-HeN20-7103 strain was located along with the attenuated IBDV, which corresponds to genotype A8B1 of the recently proposed classification scheme, on the branch of the phylogenetic tree. The amino acid sequence comparisons further highlighted the specific characteristics of IBDV-HeN20-7103 with mutation H253Q compared to the attenuated strain. Animal experiments showed that IBDV-HeN20-7103 could induce serious bursal lesions without mortality, which revealed a unique cause of disease in this flock. The identification of such a strain reaffirms the complexity of IBDV evolution and prevalence.
传染性法氏囊病病毒（IBDV）是传染性法氏囊病（IBD）的病原体，主要损害法氏囊，而法氏囊是禽类的一个中枢免疫器官。作为一种RNA病毒，由于包括自然选择压力在内的多种因素共同作用，IBDV易于发生突变。在本研究中，在中国中部一个受感染的鸡群中鉴定出一种与法氏囊损伤相关的自然发生的突变IBDV，即IBDV-HeN20-7103株。克隆了其全长基因组，序列分析表明，IBDV-HeN20-7103株与减毒IBDV位于一起，在系统发育树的分支上，这与最近提出的分类方案中的A8B1基因型相对应。氨基酸序列比较进一步突出了IBDV-HeN20-7103与减毒株相比具有H253Q突变的特异性特征。动物实验表明，IBDV-HeN20-7103可诱导严重的法氏囊病变但无死亡，这揭示了该鸡群中独特的致病原因。这种毒株的鉴定再次证实了IBDV进化和流行的复杂性。
