Experimental Infection of Goats with Mycobacterium avium subsp. hominissuis: a Model for Comparative Tuberculosis
J Schinköthe1, P Möbius2, H Köhler2
1Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Greifswald, Insel Riems, Germany.
Abstract:
Mycobacterium avium subsp. hominissuis (MAH) is an opportunistic pathogen that causes infections in man and animals. In this study, 18 goat kids were inoculated orally with a high dose of MAH. One group of goats (n = 9) developed severe clinical disease for up to 2-3 months post inoculation (mpi). At necropsy examination, there were ulcerative and granulomatous lesions in gut-associated lymphoid tissue and granulomas with extensive necrosis in the lymph nodes (LNs) of the cranial mesenteric lymphocentre (CMLNs). Culture revealed growth of MAH in all lesions with systemic spread. A second group of goats were healthy at the end of the trial (13 mpi); however, all had extensive granulomas in the CMLNs, but no extra-intestinal spread of bacteria. Moderate faecal shedding occurred in all goats up to 2 mpi. Microscopical characterization of the granulomas revealed solid non-necrotic, necrotic, calcified and fibrocalcified granulomas with resemblance to those seen in human and bovine tuberculosis. The two different courses of disease, with highly heterogenic lesions, systemic spread in goats with severe clinical disease and the development of granulomas of all stages in the surviving goats, makes the experimental infection of goats with MAH a valuable model for tuberculosis research. This model might allow new insights into host-pathogen interaction and anti-mycobacterial compound testing.
Insights
Mycobacterium avium subsp. hominissuis (MAH) causes varied disease in goats, from severe clinical signs to asymptomatic granulomas. This goat model offers valuable insights for tuberculosis research and drug testing.
Area of Science:
- Veterinary Medicine
- Infectious Diseases
- Pathology
Background:
- Mycobacterium avium subsp. hominissuis (MAH) is an opportunistic pathogen causing disease in humans and animals.
- Tuberculosis research requires robust animal models to study host-pathogen interactions and evaluate treatments.
Purpose of the Study:
- To investigate the pathogenesis of Mycobacterium avium subsp. hominissuis (MAH) infection in goats.
- To evaluate the suitability of experimentally infected goats as a model for tuberculosis research.
Main Methods:
- 18 goat kids were orally inoculated with a high dose of MAH.
- Animals were monitored for clinical signs, necropsied, and lesions examined.
- Mycobacterial cultures and histopathological analyses were performed on tissues.
Main Results:
- Two distinct disease outcomes were observed: severe clinical disease with systemic spread and asymptomatic infection with granulomas.
- Lesions included ulcerative and granulomatous inflammation in lymphoid tissues and extensive necrosis in lymph nodes.
- Granulomas exhibited various stages, including necrotic, calcified, and fibrocalcified forms, similar to tuberculosis.
Conclusions:
- Experimental MAH infection in goats presents a valuable model for studying tuberculosis.
- This model can facilitate research into host-pathogen interactions and the efficacy of anti-mycobacterial compounds.
