Mycobacterium orygis and its unseen impact: re-evaluating zoonotic tuberculosis in animal and human populations

Globally, the incidence and burden of zoonotic tuberculosis (zTB) in humans are underestimated. Earlier, it was considered that Mycobacterium bovis (M. bovis) was the sole etiology of zTB; however, novel zoonotic species of mycobacteria, namely, Mycobacterium orygis (M. orygis), is also implicated and often neglected pathogen, which necessitates more attention. M. orygis has been recently included under the members of the Mycobacterium tuberculosis complex (MTBC), and it shares genetic similarities with other members of this complex. M. orygis can cause tuberculosis (TB) in animals and humans. This bacterium is harbored by a wide range of host species; however, the exact host spectrum is not well understood. In recent years, M. orygis has received considerable interest due to its frequent isolation in zTB infections that often originated from tuberculosis-endemic countries than non-endemic countries. Therefore, the zoonotic potential of this bacterium highlights the importance of "One Health" approaches in understanding its possible routes of transmission, reservoir, ecology, and pathogenicity. Moreover, the occurrence of M. orygis in tuberculosis-endemic countries with limited resources poses further challenges in disease surveillance and identification, emphasizing the significance of collaborative measures across multiple sectors to monitor and control its spread. This review focuses on the current knowledge of M. orygis and underscores the importance of this neglected pathogen, which has potential impacts on both human and animal health.