Vaccination of white-tailed deer with Mycobacterium bovis bacillus Calmette-Guérin (BCG): Effect of Mycobacterium avium ssp. paratuberculosis infection

Authors: Palmer, Mitchell; Kanipe, Carly; LEHMAN, KIMBERLY - US Department Of Agriculture (USDA); THACKER, TYLER - US Department Of Agriculture (USDA); Putz, Ellie; Boggiatto, Paola

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2023
Publication Date: 10/4/2023
Citation: Palmer, M.V., Kanipe, C.R., Lehman, K.A., Thacker, T.C., Putz, E.J., Boggiatto, P.M. 2023. Vaccination of white-tailed deer with Mycobacterium bovis bacillus Calmette-Guérin (BCG): Effect of Mycobacterium avium ssp. paratuberculosis infection. Microorganisms. https://doi.org/10.3390/microorganisms11102488.
DOI: https://doi.org/10.3390/microorganisms11102488

Interpretive Summary: Bovine tuberculosis is caused by the bacterium, Mycobacterium bovis (M. bovis). M. bovis can cause tuberculosis in cattle and humans. Due to animal and public health concerns, in 1917 USDA initiated a bovine tuberculosis eradication program that is still in effect today. Although great progress has been made, eradication of the disease has not been achieved. One major obstacle is the presence of a wildlife reservoir of M. bovis in the form of white-tailed deer. Infected white-tailed deer mingle with cattle and often share feed with cattle, in the process transmitting disease. Since the discovery of M. bovis in wild white-tailed deer in Michigan, over 82 cattle herds have been infected. The source of infection has been found to be wild white-tailed deer. One approach to decreasing deer-to-deer and deer-to-cattle transmission would be vaccination of deer using the human tuberculosis vaccine known as BCG. BCG has been shown to decrease disease severity in experimentally infected deer. The efficacy of BCG vaccination may be influenced by prior exposure of deer to other mycobacteria, many of which are found in the environment and known as non-tuberculous mycobacteria (NTM). One NTM to which deer may be exposed, especially those near cattle farms is the NTM that causes Johne's disease in cattle and other ruminants. We showed that prior natural exposure to the causative agent of Johne's disease did not have an effect on BCG efficacy in experimentally deer. BCG should be effective in deer, even those exposed to NTM.

Technical Abstract: In many parts of the world, bovine tuberculosis eradication efforts are hampered by wildlife reservoirs of M. bovis, which serve as a constant source of M. bovis for nearby cattle. The human tuberculosis vaccine, M. bovis BCG has been investigated for use in several wildlife species, including deer. In the US, white-tailed deer in Michigan have been the source of infection for over 82 cattle herds since M. bovis was discovered in deer in 1995. The efficacy of BCG may be influenced by many factors including, prior exposure or infection with non-tuberculous mycobacteria, those species other than members of the M. tuberculosis complex. Mycobacterium avium subspecies paratuberculosis (Map) infection is not uncommon in ruminants such as deer. Using natural exposure to Map and experimental infection with M. bovis, we demonstrate that Map exposure or infection did not negatively impact BCG vaccine efficacy as measured by lesion severity scores.