ARS | Publication request: Experimental Infection of Reindeer (Rangifer Tarandus)with Mycobacterium Bovis; Pathological and Immunological Findings

Submitted to: Wildlife Disease Association Annual Meeting
Publication Acceptance Date: August 27, 2004
Publication Date: August 27, 2004
Citation: Palmer, M.V., Waters, W.R., Thacker, T.C., Stoffregen, W.C., Slaughter, R.E., Jones, S.L., Pitzer, J.E., Minion, F.C. 2004. Experimental Infection Of Reindeer (Rangifer Tarandus)with Mycobacterium Bovis; Pathological And Immunological Findings [abstract]. Wildlife Disease Association. P.402-403.

Technical Abstract: In the United States all species of Cervidae are included in the uniform rules and methods for the eradication of bovine tuberculosis. However, in reindeer, infection with M. bovis is rare and false positive results on diagnostic tests are common. In order to describe the pathologic changes associated with M. bovis infection and evaluate the effectiveness of intradermal tuberculin testing and a blood based assay for interferon-gamma (IFN-gamma) as means of diagnosis of tuberculosis in reindeer, 11 reindeer were inoculated intratonsilarly with 2 x 10**4 CFU of M. bovis. Four non-inoculated reindeer served as negative controls. The comparative cervical test (CCT) was done on all reindeer 3 and 8 months after inoculation. Blood was collected monthly for IFN-gamma analysis. Thirteen months after inoculation, all reindeer were euthanized and examined. Lesions in reindeer were fewer in number and less widely disseminated than those seen in white-tailed deer similarly inoculated. The CCT accurately identified M. bovis-inoculated reindeer, but false positive results were common among negative control reindeer. Modifications in the USDA's method for interpretation of the CCT decreased false positive results. A blood-based assay to measure IFN-gamma production showed that mycobacteria-specific IFN-gammma responses by M. bovis-infected reindeer exceeded those of negative control reindeer. As with the CCT, positive IFN-gamma responses to crude mycobacterial antigens were also detected in negative control reindeer. ESAT-6 and CFP-10 are antigens unique to Mycobacteria spp. within the tuberculosis complex. While use of these antigens did not interfere with detection of M. bovis-infected reindeer, it did decrease the number of false positive results in negative control reindeer.