Detection of Mycobacterium tuberculosis in Captive Sloth Bears in Karnataka

Tuberculosis (TB) is contagious disease of zoonotic importance. The disease is caused by organisms belonging to the Mycobacterium spp. The important species responsible for TB are M. bovis, M. tuberculosis and M. avium. Mycobacteria infect a broad range of species including humans, wild mammals and birds in captivity and free-living state. Diagnosis of mycobacterial infection is very important from the public health perspective, particularlyin captive animals. In the present study a total of 25 sloth bears kept in bear rescue center, Bannerghatta National Park, Bengaluru, Karnataka, India were screened for tuberculosis. The Bronchial wash, direct tracheal tube smear and fecal samples from all the sloth bears were subjected for Ziehl-Neelsen staining technique. Among these samples, only one fecal sample was found positive for M. tuberculosis. None of the bronchial wash samples were positive by culturing in Lowenstein Jensen (LJ) media. Six samples yielded M. tuberculosis by culturing in Mycobacteria Growth Indicator Tube (MGIT) 960 media. Three out of 25 bronchial wash samples were positive for M. tuberculosis by RT micro PCR. None of the blood samples of sloth bears were positive for M. tuberculosis species by PCR. This study demonstrated that culturing in MGIT960 media and RT micro PCR are the useful diagnostic tests for detection and identification M. tuberculosis in captive sloth bears. This study will be helpful for the screening of the tuberculosis in animals and prevent the spreading of the infection to other wild animals and humans visiting to the Biological National Park.