Infection of swine with Mycobacterium bovis as a model of human tuberculosis

Abstract

Swine were infected with Mycobacterium bovis to develop a model for pulmonary and disseminated tuberculosis in humans. Pigs were inoculated with various doses of M. boris by intravenous (iv), intratracheal (int), or tonsillar routes. Animals were euthanized between 17 and 60 days after inoculation, and tissues were collected for culture and histopathologic examination. Lesions of disseminated tuberculosis were found in pigs given 104 or 108 cfu of M. bovis iv or int; localized pulmonary disease was found in pigs given 102 or 103 cfu of M. bovis int. Lesions ranged from well- organized tubercles with coagulative necrosis, epithelioid macrophages, and fibrosis to large expansive tubercles with liquefactive necrosis and extracellular growth of M. bovis. Tuberculous meningitis was observed in animals given M. bovis iv. Swine infected with M. bovis are a useful animal model for elucidating the mechanisms of pathogenesis and host defense to tuberculosis in humans.