A case of Mycobacterium terrae infection in cattle in Bosnia and Herzegovina
Non-tuberculous Mycobacteria (NTM) are worldwide opportunist pathogens which can infect both humans and animals. Infections with these mycobacteria can have various clinical manifestations and may cause allergic sensitisation of the infected animals. Besides the potential zoonotic risk these infections in cattle can interfere with intradermal tuberculin test and hamper the in vivo diagnosis of bovine tuberculosis resulting in significant economic losses due to unnecessary restrictions and culling of reactor animals. Here we describe a case of Mycobacterium terrae infection in a cow on a small dairy household in Central Bosnia and Herzegovina. For the identification of the disease and causative agent comparative tuberculin skin test (TST), pathomorphology, microbiology and molecular methods were applied. At necropsy of a cow that was positive on annual routine tuberculin skin testing, severe multifocal granulomatous dermatitis and paniculitis were observed. Furthermore, moderate granulomatous (parasitic) colitis was also noted. Histopathology revealed granulomatous dermatitis. Ziehl-Neelsen staining was negative for acid fast bacteria. Regional and thoracic lymph nodes, and skin lesions were submitted for microbiology examinations. Isolated bacteria were identified by molecular methods as Mycobacterium terrae. Our findings confirms the difficulties that non- tuberculous mycobacteria can cause in the in vivo diagnosis of mycobacterial infections, especially in conjunction with parasitic infestations.