一株肾型鸡传染性支气管炎病毒RP-NR22株的分离鉴定及致病性研究OA

During February 2022,a contagious illness leading to significant kidney impairment was identified in a flock of white-feathered broiler chickens at a large farm in Shandong Province,China.However,the specific etiological factors remain unclear.In order to ascertain the causative agent of the disease,samples were gathered for RT-PCR testing,virus isolation,and S1 gene sequencing analysis.A nephropathogenic strain of avian infectious bronchitis virus(IBV)was isolated and designated as RP-NR22.Through analysis of genetic evolution centered on the S1 gene,it was determined that this strain is part of the GI-19 lineage and showcases mutations at critical glycosylation sites.In order to explore the pathogenic features of RP-NR22,the virus was administered to SPF chickens to evaluate its pathogenicity.Animal experiments have validated that RP-NR22 induced kidney lesions in all SPF chickens(10/10)and resulted in a mortality rate of 40%(4/10).The commercially available IBV ELISA kits commonly used at present have shown an inability to identify antibody responses in chickens infected with the virus.This report marks the initial identification of a nephropathogenic IBV strain isolated from both domestic and international sources.The findings of this study offer foundational resources and information for advancing research on the pathogenic pathways of nephropathogenic IBV and the development of effective preventive and control measures.