IN VITRO THIOCARBAMATE RESISTANCE OF TRICHOPHYTON MENTAGROPHYTES

Abstract

The in vitro resistance of Trichophyton mentagrophytes to piritetrate (M-732), a new thiocarbamate antidermatophytic compound, was studied in comparison with a reference thiocarbamate, tolnaftate. It was found that this fungus was not readily able to develop resistance to either of these compounds. After a long period of serial subculturing of six strains in Sabouraud dextrose broths and on Sabouraud dextrose agar slants containing increasing concentrations of compound, only one strain of each eventually became highly resistant to tolnaftate in either media. None of the strains acquired resistance to piritetrate. The two tolnaftate-resistant strains thus obtained manifested morphological, biochemical and pathological changes and showed partial cross-resistance to piritetrate.