Trichophyton rubrum: Relationship between susceptibilities to antifungal agents and species specificities / 第二军医大学学报

ABSTRACT

Objective: To study the relationship between susceptibilities of Trichophyton rubrum strains to antifungal agents and their species specificities. Methods: The susceptibilities of Trichophyton rubrum strains to itraconazole, ketoconazole, fluconazole, terbinafine, naftifine, 5-flucytosine and amphotericin B were evaluated using a modified microdilution method. The relationship between susceptibilities and genotypes and phenotypes of Trichophyton rubrum strains with different origins was analyzed by random amplified polymorphic DNA (RAPD). Results: The Trichophyton rubrum strains showed narrow minimum inhibitory concentration (MIC) ranges to terbinafine (0.016-0.032 μg/ml), naftifine (0.032-0.063 μg/ml) and itraconazole (0.25-1 μg/ml), whereas they showed broader MIC ranges to ketoconzole (0.25-2 μg/ml) and fluconazole (1-32 μg/ml). MICs of Trichophyton rubrum strains to terbinafine (M0 = 0.032 μg/ml) and naftifine (M0 = 0.032 μg/ml) were the lowest among 7 antifungal agents. Wilcoxon test (Kruskal-Wallis test) suggested that there was no significant relationship of MICs to terbinafine, naftifine, itraconazole and amphotericin B with the genotypes, phenotypes and origins of the Trichophyton rubrum strains. Conclusion: The antifungal susceptibility of Trichophyton rubrum strains may not be related to their genotypes, phenotypes or from which part of the body they are isolated.