Tuberculosis (TB) in goats (. Capra hircus) is due to infection with members of the Mycobacterium tuberculosis complex (MTC), mainly Mycobacterium bovis and Mycobacterium caprae. We report a comparative experimental infection of goats with M. bovis, M. caprae and M. tuberculosis strains. We hypothesized that goats experimentally infected with different members of the MTC would display different clinical pictures. Three groups of goats were challenged with either M. bovis SB0134 (group 1, n=. 5), M. caprae SB0157 (group 2, n=. 5) and M. tuberculosis SIT58 (group 3, n= 4). The highest mean total lesion score was observed in M. bovis challenged goats (mean 15.2, range 9-19), followed by those challenged with M. caprae (10.8, 2-23). The lowest score was recorded in goats challenged with M. tuberculosis (3, 1-6). Culture results coincided with the lesion scores in yielding more positive pools (7/15) in M. bovis challenged goats. By contrast, only three pools were positive from goats challenged M. tuberculosis (3/12) and with M. caprae (3/15), respectively. Differences in the performance of the intradermal and gamma-interferon (IFN-γ) tests depending of the group were observed since all goats from group 1 were diagnosed using intradermal test and these goats reacted earlier to the IFN-γ assay in comparison to the other groups. This study confirmed that goats experimentally infected with different members of the MTC display different clinical pictures and this fact may have implications for MTC maintenance and bacterial shedding.
Bibliographical noteFunding Information:
TB research funding is acknowledged to AGL2012-36171 and AGL2014-56305 (MINECO, Spain and FEDER) and EU FP7 grants WildTBvac #613779 and ANTIGONE #278976. Javier Bezos is recipient of a Torres-Quevedo contract (PTQ-12-05812) funded by the Ministry of Economy and Competitiveness and the European Social Fund . Authors are grateful to Marisa de la Cruz, Antonio Rodríguez-Bertos, Álvaro Fernández and Sergio González for the technical assistance.
- Animal tuberculosis
- Domestic goat
- Lesion score
- Strain genotype