Department of Pathology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh.
French Agency for Food, Environmental and Occupational Health Safety (ANSES) Ploufragan-Plouzané-Niort Laboratory, Avian and Rabbit Epidemiology and Welfare Unit, OIE Reference Laboratory for Infectious Bursal Disease Ploufragan, France.
Avian Pathol. 2021 Apr;50(2):190-206. doi: 10.1080/03079457.2021.1873245. Epub 2021 Feb 8.
Infectious bursal disease virus (IBDV) of chickens is a birnavirus with a bi-segmented double-stranded RNA genome, the segments designated as A and B. We performed phylogenetic analysis using a 366-bp fragment of segment A (nt 785-1150) and a 508-bp fragment of segment B (nt 328-835) of IBDV. A total of 463 segment A and 434 segment B sequences from GenBank, including the sequences of eight recent Bangladeshi isolates, were used in the analysis. The analysis revealed eight genogroups of segment A under serotype 1, designated as A1 (classical), A2 (US antigenic variant), A3 (very virulent), A4 (dIBDV), A5 (atypical Mexican), A6 (atypical Italian), A7 (early Australian) and A8 (Australian variant), and a single genogroup under serotype 2, designated as A0. On the other hand, segment B could be categorized into five genogroups irrespective of serotype, these being B1 (classical-like), B2 (very virulent-like), B3 (early Australian-like), B4 (Polish & Tanzanian) and B5 (Nigerian). Segment B of serotype 2 strains clustered within genogroup B1. With the bi-segmented genome of IBDV, these differences would allow for a total of 45 possible assortments. Based on the combinations of segment A and segment B genogroups observed in 463 IBDV strains, a total of 15 genotypes could be recognized. Recent Bangladeshi IBDV strains, isolated in 2016, appeared to be segment reassortants having segment A of genogroup A3 (very virulent) and segment B of genogroup B3 (early Australian-like). An extended system of nomenclature of IBDV strains is proposed.
鸡传染性腔上囊病病毒（IBDV）是一种具有双分段双链 RNA 基因组的双 RNA 病毒，该基因组分为 A 段和 B 段。我们使用 IBDV 的 A 段 366bp 片段（nt 785-1150）和 B 段 508bp 片段（nt 328-835）进行了系统进化分析。总共使用了来自 GenBank 的 463 个 A 段和 434 个 B 段序列，其中包括 8 个最近的孟加拉国分离株的序列。分析显示，血清型 1 的 A 段有 8 个基因型，分别命名为 A1（经典型）、A2（美国抗原变异型）、A3（非常强毒力型）、A4（dIBDV）、A5（非典型墨西哥型）、A6（非典型意大利型）、A7（早期澳大利亚型）和 A8（澳大利亚变异型），而血清型 2 只有一个基因型，命名为 A0。另一方面，B 段可以分为 5 个基因型，无论血清型如何，这些基因型为 B1（经典样）、B2（非常强毒力样）、B3（早期澳大利亚样）、B4（波兰和坦桑尼亚）和 B5（尼日利亚）。血清型 2 菌株的 B 段聚类在 B1 基因型内。由于 IBDV 的双分段基因组，这些差异总共可以产生 45 种可能的组合。根据在 463 株 IBDV 中观察到的 A 段和 B 段基因型的组合，总共可以识别出 15 种基因型。2016 年分离的最近的孟加拉国 IBDV 株似乎是具有 A 段为 A3 基因型（非常强毒力）和 B 段为 B3 基因型（早期澳大利亚样）的片段重组体。提出了一种扩展的 IBDV 株命名系统。
