Determining the persistence of Mycobacterium bovis bacille Calmette-Guerin Danish in select tissues of orally vaccinated feral swine (Sus scrofa ssp.).

ABSTRACT

Mycobacterium bovis bacille Calmette-Guerin (BCG) is being considered for vaccination of feral swine (Sus scrofa ssp.). Since BCG is a live bacterium, evaluation of its safety and persistence in tissues is important. Fifteen feral swine received approximately 4.5 × 10(6) colony forming units of BCG Danish via oral bait. Four animals received bait without BCG. At 1, 3, 6, and 9 months post-vaccination, four vaccinates were euthanized. Non-vaccinates were euthanized at 9 months. Clinical signs were not noted in vaccinated pigs at any time. Tissues from all 20 pigs were culture-negative for mycobacteria. Based on our data, BCG is safe and appears not to persist in feral swine tissues after one month post-oral vaccination. However, further work must be performed at higher doses, and on a larger number of animals representing the target population, and further evaluation of persistence in tissues within the first month post-vaccination is needed.