Pranay M, Balasubramaniam A, Ponnusamy P, Balachandran P, Sukumar K
Department of Veterinary Microbiology, Veterinary College & Research Institute, Tamil Nadu Veterinary & Animal Sciences University, Namakkal - 637002, Tamil Nadu, India.
Department of Veterinary Pathology, Veterinary College & Research Institute, Tamil Nadu Veterinary & Animal Sciences University, Namakkal - 637002, Tamil Nadu, India.
Vet Ital. 2025 Jun 20;61(3). doi: 10.12834/VetIt.3760.34630.2.
Avian reovirus (ARV) is a major causative agent of viral arthritis (VA), tenosynovitis, and malabsorption syndrome (MAS) in chickens, with significant economic consequences due to growth retardation, reduced production performance, and immunosuppression. Despite routine vaccination of breeder chickens against ARV, cases of VA and MAS continue to be reported in commercial flocks in recent years. Moreover, there is a lack of recent data on the genetic characteristics of circulating field ARV strains in India. In light of these concerns, a study was conducted to investigate the involvement of ARV in chickens exhibiting clinical signs suggestive of VA or MAS. Samples were collected from 27 commercial broiler and desi-chicken flocks across the mid-western region of Tamil Nadu, South India. Molecular confirmation was performed using reverse transcription polymerase chain reaction (RT-PCR) targeting a partial region of the σC gene within the S1 segment. Of the 27 flocks sampled, only two samples - both from desi-chickens aged two and three weeks - tested positive for ARV. Sequence analysis of these positive samples, compared against available ARV sequences in GenBank (including vaccine strains) revealed that the identified strains clustered within ARV genogroup II. This represents the first report of cluster II ARV in India, indicating the circulation of genetically distinct ARV strains in Indian poultry populations. These findings underscore the need for routine molecular surveillance of ARV genotypes in India and highlight the potential mismatch between circulating field strains and current vaccine strains. Comprehensive genotype monitoring is essential to upgrade vaccine design and implement effective control strategies for ARV-associated diseases in Indian poultry production.
禽呼肠孤病毒（ARV）是鸡病毒性关节炎（VA）、腱鞘炎和吸收不良综合征（MAS）的主要病原体，由于生长发育迟缓、生产性能下降和免疫抑制，会造成重大经济损失。尽管种鸡常规接种了抗ARV疫苗，但近年来商业鸡群中仍不断有VA和MAS病例报告。此外，印度缺乏关于流行的田间ARV毒株遗传特征的最新数据。鉴于这些问题，开展了一项研究，以调查ARV在表现出VA或MAS临床症状的鸡中的感染情况。从印度南部泰米尔纳德邦中西部地区的27个商业肉鸡和本地鸡群中采集了样本。使用针对S1片段中σC基因部分区域的逆转录聚合酶链反应（RT-PCR）进行分子确认。在采集的27个鸡群中，只有两个样本——均来自两周龄和三周龄的本地鸡——检测出ARV呈阳性。将这些阳性样本的序列分析结果与GenBank中现有的ARV序列（包括疫苗株）进行比较，发现鉴定出的毒株聚集在ARV基因群II内。这是印度关于基因群II ARV的首次报告，表明印度家禽群体中存在基因不同的ARV毒株。这些发现强调了印度对ARV基因型进行常规分子监测的必要性，并突出了流行的田间毒株与当前疫苗株之间可能存在的不匹配。全面的基因型监测对于改进疫苗设计和实施印度家禽生产中ARV相关疾病的有效控制策略至关重要。
