RESUMO
Bovine tuberculosis is a zoonotic disease, and although its incidence has dramatically decreased in developed countries where effective control measures are applied, it still remains a potential health hazard in the developing world. Tuberculosis of the oral cavity is extremely rare and is usually secondary to pulmonary involvement. We present the unusual case of an immunocompetent 6-year-old child residing in an urban area with primary oral tuberculosis due to Mycobacterium bovis, which was confirmed by the application of a molecular genetic approach. M. bovis belongs to Mycobacterium tuberculosis complex which comprises species with close genetic relationship, and for this reason, the use of new molecular techniques is a useful tool for the differentiation at species level of the closely related members of this complex.