Shah Abid Ullah, Peddireddi Lalitha, Wood Beverly, Hemida Maged Gomaa
Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, Brookville, NY 11548NY, USA.
North Carolina Veterinary Diagnostic Laboratory Services, 4400 Reedy Creek Rd, Raleigh, NC 27607, United States of America.
Infect Genet Evol. 2025 Apr;129:105723. doi: 10.1016/j.meegid.2025.105723. Epub 2025 Jan 30.
Avian infectious bronchitis virus (AIBV) infection remains one of the significant challenges for the poultry industry due to the high rates of morbidity, mortality, and poor production performance. The AIBV genome is prone to frequent changes due to the possibility of drift and recombination between various genotypes. Despite the massive administration of several types of vaccines, many outbreaks of AIBV continue to be reported worldwide. One of the major goals of this study was to monitor genetic changes in the viral genomes of some recent field isolates of the AIBV from broiler chickens. To achieve these goals, we tested several pools of tissue specimens (trachea and kidneys) from some suspected AIBV outbreaks in broiler chickens by quantitative real-time PCR (q-RT-PCR). We selected two samples, one from the trachea (IBV-4) and one from the kidney (AIBV-6), for the next-generation sequencing (NGS). The full-length genomes of these two isolates were deposited in the GenBank (Accession Numbers: PQ468962 and PQ468963). The viral genome size of AIBV-4 and AIBV-6 was 27,475 and 27,469 nucleotides in length. AIBV-4 have typical AIBV genome organization (5'UTR, ORF1a, ORF1b, S, 3a, 3b, E, M, 4b, 5a, 5b, N, and 3'UTR), while AIBV-6 lack 5b. These two AIBV isolates belong to sublineage-1 of the genotype GI-1 based on the phylogenetic using the full-length, the S, and the N protein sequences. The S1/S2 cleavage sites show polybasic amino acid sequences (RR-F-RR) as direct evidence of virulence of these isolates. The analysis shows multiple recombination events of these isolates with some natural and vaccine strains. The potential major parent for both AIBV-4 and AIBV-6 was AIBV Beaudette. Active and vigilant monitoring of the AIBV sequences of the currently circulating strains in chickens is highly encouraged to help develop novel vaccines and diagnostic assays that match the field circulating strains.
禽传染性支气管炎病毒（AIBV）感染仍是家禽业面临的重大挑战之一，因为其发病率、死亡率高且生产性能不佳。由于不同基因型之间可能发生漂移和重组，AIBV基因组容易频繁变化。尽管大量接种了多种疫苗，但全球仍不断有AIBV暴发的报道。本研究的主要目标之一是监测肉鸡中一些近期AIBV野外分离株病毒基因组的遗传变化。为实现这些目标，我们通过定量实时PCR（q-RT-PCR）检测了来自肉鸡一些疑似AIBV暴发的多个组织标本库（气管和肾脏）。我们选择了两个样本，一个来自气管（IBV-4），一个来自肾脏（AIBV-6），用于下一代测序（NGS）。这两个分离株的全长基因组已存入GenBank（登录号：PQ468962和PQ468963）。AIBV-4和AIBV-6的病毒基因组大小分别为27475和27469个核苷酸。AIBV-4具有典型的AIBV基因组结构（5'UTR、ORF1a、ORF1b、S、3a、3b、E、M、4b、5a、5b、N和3'UTR），而AIBV-6缺少5b。根据全长、S和N蛋白序列的系统发育分析，这两个AIBV分离株属于基因型GI-1的亚分支-1。S1/S2裂解位点显示多碱性氨基酸序列（RR-F-RR），作为这些分离株毒力的直接证据。分析表明这些分离株与一些自然毒株和疫苗株发生了多次重组事件。AIBV-4和AIBV-6的潜在主要亲本是AIBV Beaudette。强烈建议对鸡群中当前流行毒株的AIBV序列进行积极和警惕的监测，以帮助开发与野外流行毒株相匹配的新型疫苗和诊断方法。
