一起牛呼吸道综合征病原分析和鉴定

Identification and pathogen analysis of bovine respiratory disease complex

牛呼吸疾病综合征(bovine respiratory disease complex,BRDC)是由多种病原和环境共同作用引起的多症状疾病,给牛养殖业带来了巨大经济损失。2023年3月陕西某肉牛场暴发BRDC,为了解造成此次病情的病原,采集4份发病牛的鼻腔深部棉拭子和4份病死牛组织样品,采用qPCR和RT-qPCR方法,分别对样品进行牛支原体(Mycoplasma bovis,M.bovis)、牛副流感病毒3型(bovine parainfluenza virus type 3,BPIV-3)、牛传染性鼻气管炎病毒(infectious bovine rhinotracheitis virus,IBRV)、牛冠状病毒(bovine coronavirus,BCoV)、牛呼吸道合胞体病毒(bovine respiratory syncytial virus,BRSV)、多杀性巴氏杆菌(Pasteurella multocida,P.multocida)、溶血性曼氏杆菌(Mannheimia haemolytica,M.haemolytica)、化脓隐秘杆菌(Arcanobacterium pyogenes,A.pyogenes)、昏睡嗜血杆菌(Histophilus somnus,H.somnus)共9种BRDC相关病原开展核酸检测。结果显示,M.bovis、P.multocida和H.somnus阳性率均为75%、M.haemolytica阳性率为50%、A.pyogenes阳性率为62%、BCoV阳性率为25%,证实该场BRDC病情由以上6种病原混合感染引起;对病原进行分离鉴定获得1株溶血曼氏杆菌和1株巴氏杆菌,并开展了药敏实验分析。研究结果为该牛场犊牛呼吸道疾病防控和针对性治疗提供了参考依据。

Bovine respiratory disease complex(BRDC)is a multi-symptom disease caused by various pathogens and environmental factors,resulting in significant economic losses for cattle farming industry.In March 2023,BRDC broke out in a beef cattle farm in Shanxi province.To detect the pathogens,4 swabs from the deep nasal cavity of infected cattle and 4 tissue samples from dead cattle were collected.These samples were detected by qPCR and RT-qPCR for 9 pathogens related to BRDC,including M.bovis,bovine parainfluenza virus type 3(BPIV-3),infectious bovine rhinotracheitis virus(IBRV),bovine coronavirus(BCoV),bovine respiratory syncytial virus(BRSV),P.multocida,M.haemolytica,Arcanobacterium pyogenes(A.pyogenes)and Histophilus somnus(H.somnus).The results indicated that the positive rate of M.bovis,P.multocida andH.somnus was 75%,the positive rate of M.haemolytica was 50%,A.pyogenes was 62%,the positive rates of BCoV were 25%.It was proved that the BRDC was caused by the mixed infection of the above 6 pathogens.The pathogens were isolated and identified to obtain 1 strain of M.hemolytia and 1 strain of P.multocida,and the drug susceptibility test was carried out.The results provided a reference for the prevention and control of calf respiratory diseases and the formulation of targeted treatment measures.