Biochemical correlation of M. vaccae with M. leprae

The biochemical tests, namely, niacin, catalase, nitrate reduction, tween hydrolysis, tellurite reduction, arylsulfatase and urease tests were carried out for all the mycobacteria which are immunogenically closely related to M. leprae. Among them only M. vaccae shows closest relationship with M. leprae when compared with its communicated data. Except for the tellurite reduction test which was variable in case of M. leprae, all the other tests were found similar to that of M. leprae. In the next experiment, the thin-layer chromatographic pattern of mycolates from M. leprae has been compared with that of M. leprae. The presence of Keto-mycolate in the cell wall structure of both M. vaccae and M. leprae also reflects their biochemical relationship at their ultrastructural level.