Runyon group III atypical mycobacteria as a cause of tuberculosis in a rhesus monkey

Bilateral draining fistulas which communicated with the cheek pouches were noted in the threat region of an adult femal Macaca mulatta receiving isoniazid for tuberculosis prophylaxis. Necrospy findings included enlargedregional lymph nodes and ulceration of cheek pouch mucous membranes. Acid-fast bacilli were demonstrated in tissue section. Cultures of the regional lymph nodes and cheek pouch mucous membrane yielded Runyon Group III mycobacteria. Intrapalpebral tuberculin tests with homologous mycobacterial antigen (Battery strain PPD) and Kochs Old Tuberculin were performed in an unsuccessful attempt to identify additional infected monkeys. This case is considered significant because of the unusual manifestation of mycobacterial disease and its occurrence in an animal receiving isoniazid at levels considered sufficient for the prevention of tuberculosis.