Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2002
Publication Date: N/A
Interpretive Summary: White-tailed deer are wildlife reservoirs of bovine tuberculosis within the United States. The presence of this reservoir host seriously threatens ongoing efforts to eradicate this disease from cattle. Captive deer, in addition to wild deer, may also become infected with this agent. Thus, it is of interest to develop tests to detect infected white-tailed deer. In the present study, it was determined that tuberculous deer produce antibodies to the bacterium and that these antibodies are detectable by simple laboratory methods. Since this technology is easily transferred to diagnostic laboratories, serological assays may prove practical for use in detecting tuberculosis infection in captive white-tailed deer. These findings will be useful for the development of improved methods of bovine tuberculosis control, thus, benefiting the cattle industry.
Technical Abstract: White-tailed deer (Odocoileus virginianus) have recently emerged as a source of Mycobacterium bovis infection for cattle within North America. The objective of this study was to evaluate the immunoglobulin reactivity to crude mycobacterial antigens of serum obtained from M. bovis-infected deer. Deer were experimentally inoculated with M. bovis strain 1315 either by intratonsilar instillation or by exposure to M. bovis-infected (i.e., in contact) deer. To determine the temporal kinetics of the response including affects of antigen administration for comparative cervical skin testing, serum was collected periodically and evaluated by ELISA for immunoglobulin (i.e., IgG heavy and light chains) reactivity to mycobacterial antigens. Reactivity to M. bovis purified protein derivative (PPDb) exceeded (p < 0.05) the reactivity to M. avium PPD (PPDa) only after in vivo administration of PPDa and PPDb for comparative cervical testing of infected deer. The mean immunoglobulin response, as measured by ELISA, of intratonsilar-inoculated deer to a proteinase k-digested whole cell sonicate of M. bovis strain 1315 exceeded (p < 0.05) that of pre-challenge responses to this antigen at approximately 1 month post inoculation and throughout the remainder of the study (i.e., ~ 11 months). This response also exceeded (p < 0.05) that of non-infected deer. While encouraging, further studies are necessary to validate the usage of proteinase k-digested M. bovis antigens in antibody-based assays of tuberculosis.