Mycobacterium orygis – Associated Tuberculosis in Free - Ranging Rhinoceros , Nepal , 2015

contamination by interaction with wildlife. Furthermore, an additional case of M. microti infection in a cat reported in 2011 in the same region also had the SB0118 spoligotype (7), which demonstrated that this bacillus is actively circulating in animals from this area. M. microti was previously isolated on the basis of a skin test–positive result for cattle in the United Kingdom (8), which demonstrated the risk for infection in livestock. These findings raise concern on reliability of diagnostic tests used for bovine tuberculosis surveillance. M. microti, which is phylogenetically similar to M. bovis or M. caprae and widely disseminated in the environment, could be responsible for misleading diagnostic results, as demonstrated in this study. Highly specific tests are needed to accurately identify M. bovis (or M. caprae) infection at antemortem examination through use of specific antigens, such as ESAT 6 and CFP10, which are absent in M. microti and are currently used in the interferon-g test in France (9). In addition, at postmortem diagnosis, use of specific molecular tools capable of rapidly distinguishing members of the MTBC should be considered. Histopathologic analysis lacks specificity, and obtaining results for bacterial culture takes too much time for these particularly slow-growing and fastidious mycobacteria. M. microti has already been reported to cause tuberculosis in immunocompromised and immunocompetent patients in France (10). Thus, potential risk for infection of humans by consumption of raw goat milk cheese cannot be ruled out.