Introduction and objective:
Mycobacteriosis are diseases caused by acid-fast mycobacteria other than M. leprae and tuberculous mycobacteria. Animal mycobacteriosis is often caused by M. avium ssp. hominissuis. Many species of animals are susceptible to infection with this bacterium, even those kept in Zoological Gardens. The aim of the study was to determine the species of bacterium responsible for causing the disease in the tested animals.

Material and methods:
Tissue samples of two male sitatunga antelopes (Tragelaphus spekii) were analyzed. Lymph node and lung samples were subjected to anatomical examination and Ziehl-Neelsen staining. Real-time PCR was performed to confirm or rule out tuberculosis mycobacteria infection. In order to isolate the bacterial strain, tissue samples were inoculated on both solid and liquid media. HainLifescience CM tests, mass spectrometry and New Generation Sequencing were used to determine the mycobacterial species.

Results:
Results showed that atypical mycobacteria are responsible for the antelope disease. The results of the HainLifescience CM test and mass spectrometry indicated that the mycobacterium responsible for causing mycobacteriosis was M. avium. New Generation Sequencing helped to identified a subspecies that was M. avium ssp. hominissuis.

Conclusions:
The sitatunga antelope is an animal susceptible to infection by M. avium ssp. hominissuis. Considering the wide range of hosts and the easiness of interspecies transmission of the pathogen, as well as its zoonotic nature, the mycobacteriosis induced by this microorganism should not be underestimated.