IDENTIFICATION OF THE LEPROSY BACILLUS AND RELATED MYCOBACTERIA BY ANALYSIS OF MYCOCEROSATE PROFILES

Members of the phthiocerol dimycocerosate family of waxes were extract ed from Mycobacterium bovis BCG, Mycobacterium tuberculosis, Mycobacte rium kansasii, Mycobacterium marinum, Mycobacterium ulcerans and a ski n biopsy from a leprosy patient. The waxes were degraded by alkaline h ydrolysis and the mycocerosic acids converted to pentafluorobenzyl est er. Profiles of the esters, recorded using electron-capture gas-chroma tography, gave characteristic profiles for the mycocerosates from M. l eprae but those from M. bovis, M. tuberculosis and M. kansasii were su perficially similar. The mycocerosate profiles from M. marinum and M. ulcerans were similar, but distinct from the others. Selected ion moni toring negative ion-chemical ionisation gas chromatography-mass spectr ometry of of the pentafluorobenzyl esters allowed the analysis of myco cerosate isomers not revealed on gas chromatography alone. M. bovis an d M. tuberculosis had similar profiles of C29, C30 and C32 mycocerosat es; an additional C, component was also present in M. kansasii. The my cocerosates from M. marinum and M. ulcerans were C27, C29 and C30 and those from M. leprae were distinct in having C29, C30, C32, C, and C, components. These methods have excellent potential for use in the dete ction of mycobacterial disease by direct analysis of infected tissue w ithout prior cultivation of the causative agent.