Dermatophyte Test Medium: Evaluation with Nondermatophytic Pathogens

The growth and color change produced on dermatophyte test medium (DTM) by 25 strains of zoopathogenic fungi associated with human skin lesions were evaluated quantitatively. DTM only partially suppressed the development of nondermatophytes, with total growth in most instances comparable with that observed with dermatophytes. Whereas all dermatophytes induced a rapid color change on DTM, several nondermatophytic pathogens induced an equally intense and almost as rapid conversion. The rapidity of this color change and the colonial morphology of these forms on DTM could cause their misidentification as dermatophytes under clinical conditions.