Molecular detection of Mycobacterium tuberculosis complex (MTBC) in a wild Asian elephant (Elephas maximus) from Assam, India

Tuberculosis (TB) is a highly contagious bacterial disease caused by members of the Mycobacterium tuberculosis complex (MTBC), most notably Mycobacterium tuberculosis and Mycobacterium bovis. The present investigation was conducted on the carcass of an elephant found in a forest area near the Western Range, Bagori, of Kaziranga National Park, Assam, in 2024. To detect MTBC infection, TB-suspected tissue samples were collected from the dead elephant and processed aseptically in the laboratory for gross pathological examination, bacteriological analysis, and molecular confirmation of MTBC infection. Laboratory investigations confirmed the presence of MTBC infection in the elephant through the detection of acid-fast bacilli by Ziehl-Neelsen staining and the amplification of a 441 bp of Mycobacterium genus-specific hsp65 gene and a 123 bp of MTBC-specific IS6110 insertion sequence and M.bovis specific 500 bp fragment by polymerase chain reaction (PCR). These findings highlight the importance of integrated diagnostic approaches and enhanced surveillance at the wildlife-human interface to improve understanding of tuberculosis epidemiology in endangered Asian elephants.