Testing of the In Vitro Susceptibilities of Madurella mycetomatis to Six Antifungal Agents by Using the Sensititre System in Comparison with a Viability-Based 2,3-Bis(2-Methoxy-4-Nitro-5-Sulfophenyl)-5- [(Phenylamino)Carbonyl]-2 H -Tetrazolium Hydroxide (XTT) Assay and a Modified NCCLS Method

Abstract

ABSTRACT The in vitro susceptibilities of 36 clinical isolates of Madurella mycetomatis , the prime agent of eumycetoma in Africa, to ketoconazole, itraconazole, fluconazole, voriconazole, amphotericin B, and flucytosine were determined by the Sensititre YeastOne system. This system appeared to be a rapid and easy test, and by use of hyphal suspensions it generated results comparable to those of a modified NCCLS method. After 10 days of incubation, the antifungal activities of ketoconazole (MIC at which 90% of isolates were inhibited [MIC 90 ], 0.125 μg/ml), itraconazole (MIC 90 , 0.064 μg/ml), and voriconazole (MIC 90 , 0.125 μg/ml) appeared superior to those of fluconazole (MIC 90 , 128 μg/ml) and amphotericin B (MIC 90 , 1 μg/ml), with MICs in the clinically relevant range. All isolates were resistant to flucytosine (all MICs above 64 μg/ml). Based on the relatively broad range of MICs obtained for the antifungal agents, routine testing of M. mycetomatis isolates for susceptibility to antifungal agents seems to be relevant to adequate therapeutic management.