Palmer Mitchell V, Kanipe Carly, Hwang Soyoun, Thacker Tyler C, Lehman Kimberly A, Ledesma Nicholas A, Gustafson Kristophor K, Boggiatto Paola M
Bacterial Diseases of Livestock Research Unit, National Animal Disease Center, United States Department of Agriculture, 1920 Dayton Ave, Ames, IA 50010, USA.
Center for Veterinary Biologics, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ames, IA 50010, USA.
Vet Sci. 2024 Aug 7;11(8):357. doi: 10.3390/vetsci11080357.
Bovine tuberculosis is caused by , a member of the complex of mycobacterial species that cause tuberculosis in humans and animals. Diagnosis of bovine tuberculosis has relied on examinations of cell-mediated immune responses to proteins using tuberculin skin testing and/or interferon gamma release assays. Even when using these methods, disease detection during the earliest phases of infection has been difficult, allowing a window for cattle-to-cattle transmission to occur within a herd. Alternative means of diagnosis could include methods to detect or DNA in bodily fluids such as nasal secretions, saliva, or blood. During the first 8 weeks after experimental aerosol infection of 18 calves, DNA was detected in nasal swabs from a small number of calves 5, 6, and 8 weeks after infection and in samples of saliva at 1, 7, and 8 weeks after infection. However, at no time could culturable be recovered from nasal swabs or saliva. DNA was not found in blood samples collected weekly and examined by real-time PCR. Interferon gamma release assays demonstrated successful infection of all calves, while examination of humoral responses using a commercial ELISA identified a low number of infected animals at weeks 4-8 after infection. Examination of disease severity through gross lesion scoring did not correlate with shedding in nasal secretions or saliva, and calves with positive antibody ELISA results did not have more severe disease than other calves.
牛结核病由结核分枝杆菌复合群中的成员引起，该复合群中的分枝杆菌可导致人和动物患结核病。牛结核病的诊断依赖于通过结核菌素皮肤试验和/或干扰素γ释放试验来检测机体对结核分枝杆菌蛋白的细胞介导免疫反应。即便使用这些方法，在感染的最初阶段检测疾病也很困难，这使得牛群中牛与牛之间的传播有了可乘之机。其他诊断方法可能包括检测体液（如鼻分泌物、唾液或血液）中结核分枝杆菌或其DNA的方法。在对18头犊牛进行实验性气溶胶感染后的前8周内，在感染后第5、6和8周，少数犊牛的鼻拭子中检测到了结核分枝杆菌DNA，在感染后第1、7和8周的唾液样本中也检测到了该DNA。然而，在任何时候都无法从鼻拭子或唾液中培养出可培养的结核分枝杆菌。每周采集血液样本并通过实时PCR检测，未在其中发现结核分枝杆菌DNA。干扰素γ释放试验表明所有犊牛均成功感染，而使用商业ELISA检测体液免疫反应时，在感染后第4 - 8周发现感染动物数量较少。通过大体病变评分检查疾病严重程度与鼻分泌物或唾液中的排菌情况无关，ELISA抗体检测结果呈阳性的犊牛并不比其他犊牛患有更严重的疾病。
