Vaccination with Mycobacterium bovis BCG Strains Danish and Pasteur in White‐tailed Deer (Odocoileus virginianus) Experimentally Challenged with Mycobacterium bovis

Abstract

Wildlife reservoirs of Mycobacterium bovis represent serious obstacles to the eradication of tuberculosis in domestic livestock and the cause for many faltering bovine tuberculosis eradication programmes. One approach in dealing with wildlife reservoirs of disease is to interrupt inter-species and intraspecies transmission through vaccination of deer or cattle. To evaluate the efficacy of BCG vaccination in white-tailed deer, 35 deer were assigned to one of three groups; one s.c. dose of 10(7) CFU of M. bovis BCG Pasteur (n = 12); 1 s.c. dose of 10(7) CFU of M. bovis BCG Danish (n = 11); or unvaccinated deer (n = 12). After vaccination, deer were inoculated intratonsilarly with virulent M. bovis. Lesion severity scores of the medial retropharyngeal lymph node, as well as all lymph nodes combined, were reduced in vaccinated deer compared to unvaccinated deer. BCG Danish vaccinated deer had no late stage granulomas characterized by coalescent caseonecrotic granulomas containing numerous acid-fast bacilli compared to BCG Pasteur vaccinated or unvaccinated deer where such lesions were present. Both BCG strains were isolated as late as 250 days after vaccination from deer that were vaccinated but not challenged. In white-tailed deer, BCG provides protection against challenge with virulent M. bovis. Issues related to vaccine persistence, safety and shedding remain to be further investigated.

T-Cell mRNA Expression in Response toMycobacterium bovisBCG Vaccination andMycobacterium bovisInfection of White-Tailed Deer

“…After infection, BCG Danish-vaccinated animals did not have lesions in heador lung-associated lymph nodes; however, they did have minimal lung lesions (24). In contrast, BCG Pasteur-vaccinated animals had lesions in head-and lung-associated lymph nodes but none in the lungs (24). Differential gene expression in peripheral blood may explain, in part, the observed difference in lesion location.…”

“…2D). The relevance of induction of GATA3 by BCG Pasteur is not clear; however, these animals did not have lesions in the lung (24).…”

“…Unexpectedly, BCG Pasteur vaccination elicited greater GATA3 expression than vaccination with BCG Danish. After infection, BCG Danish-vaccinated animals did not have lesions in heador lung-associated lymph nodes; however, they did have minimal lung lesions (24). In contrast, BCG Pasteur-vaccinated animals had lesions in head-and lung-associated lymph nodes but none in the lungs (24).…”

“…Vaccination of WTD with the M. bovis BCG strain Danish (20) or BCG strain Pasteur (23) has been shown to be efficacious as measured by a reduction in pathology (24). To deter-mine T-cell-mediated responses induced by vaccination with these BCG strains and to correlate these responses to protection/pathology, WTD were vaccinated with either BCG Danish or BCG Pasteur and subsequently infected with virulent M. bovis.…”

Testing a molasses-based bait for oral vaccination of white-tailed deer (Odocoileus virginianus) against Mycobacterium bovis

“…BCG Danish is known to provide protection against bTB in experimentally infected deer, is commercially available, and is frequently used in vaccine efficacy trials with other host species (Palmer et al 2009;Carter et al 2012;Tompkins et al 2013;Ballesteros et al 2009b). Aseptically prepared baits were cooled in a biological safety cabinet following baking.…”