Identification of Mycobacterium phlei TMC 1523 and Mycobacterium smegmatis SN40 as Members of Mycobacterium smegmatis and Mycobacterium fortuitum, Respectively: Selective Inhibition by Trimethoprim

On the basis of a study of the effect of trimethoprim on the growth of 131 rapidly growing mycobacteria identified at the species level, it was found that two of the stains were possibly misidentified. This suspicion was confirmed by checking the salient phenotypic characters of the strains. It was found that strain TMC 1523 is not a strain of Mycobacterium phlei but of M. smegmatis and that strain SN40, previously identified as a member of M. smegmatis, is a strain of M. fortuitum.