EASY DIFFERENTIATION OF MYCOBACTERIUM-MUCOGENICUM FROM OTHER SPECIES OF THE MYCOBACTERIUM-FORTUITUM COMPLEX BY THIN-LAYER AND GAS-CHROMATOGRAPHY OF FATTY ESTERS AND ALCOHOLS

The mycolate pattern of a recently recognized mycobacterial pathogen, Mycobacterium mucogenicum (formerly Mycobacterium chelonae-like organi sm), was established for the first time. The reference strains, togeth er with 31 environmental and clinical isolates belonging to this speci es, were examined for their mycolate composition by thin-layer chromat ography. All strains tested exhibited the same mycolate profile. Mycol ates were identified as belonging to the type without additional oxyge nated chemical groups (mycolate I) and the type with a dicarboxylic gr oup (mycolate VI); the identification of the latter was reinforced by the presence of 2-octadecanol, as seen by gas-liquid capillary chromat ography. This mycolate profile permits the clear differentiation of M. mucogenicum from other related species, as members of the Mycobacteri um fortuitum complex. This fact is especially important because strain s of M. mucogenicum are Very difficult to differentiate from other spe cies of the M. fortuitum complex by means of conventional biochemical tests. Moreover, the characteristic mycolate profile exhibited by the strains of M. mucogenicum supports the recent proposal which considers them as members of a new species.