Evaluation of susceptibility of Trichophyton mentagrophytes and Trichophyton rubrum clinical isolates to antifungal drugs using a modified CLSI microdilution method (M38-A).

Onychomycosis is a common adult human mycosis, and dermatophytes of the Trichophyton genera are the most common causative agent. Many antimycotic agents are safe and highly effective for the treatment of dermatophytosis, and are available for clinical practice. Successful treatment depends on the ability of antifungal drugs to eradicate the fungal isolates.

Antifungal susceptibility testing of Trichophyton rubrum by E-test.

Trichophyton rubrum isolates were used in susceptibility testing for azoles by E-test. Voriconazole was the most and fluconazole was the less-active drug. Our results are in agreement with susceptibility data observed by researchers that used others' methodologies.

In vitro susceptibility of isolates of Sporothrix schenckii to amphotericin B, itraconazole, and terbinafine: comparison of yeast and mycelial forms.

Forty-three clinical isolates of Sporothrix schenckii derived from humans and animals were evaluated in vitro for their susceptibility to amphotericin B, itraconazole, and terbinafine. MICs were determined by the method of micro dilution in liquid media, using protocols M27-A2 for the yeast form and M38-A for the mycelial form, both standardized by the Clinical Laboratory Standards Institute. In general, higher MICs were found for the mycelial form (intervals of up to two dilutions).

In vitro methods for antifungal susceptibility testing of Trichophyton spp.

In general, methods to test the susceptibility of fungi to antifungal drugs require standardized techniques, but so far there is no methodology that is widely applicable to dermatophytes. Here we introduced modifications to the protocols from documents of the National Committee for Clinical Laboratory Standards (CLSI) M38-A and the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) that are usually applied to moulds and fermentative yeasts, in order to adjust the conditions for the growth of dermatophytes. The modifications included: growth on potato dextrose agar supplemented with 2% in-house rice flour to encourage sporulation, the addition of 2% glucose to the culture media (RPMI-1640), and an incubation temperature of 28 degrees C.

Determination of susceptibility/resistance to antifungal drugs of Trichophyton mentagrophytes isolates by a macrodilution method.

Onychomycosis is a common adult human mycosis, and dermatophytes of the Trichophyton genera are the most frequently isolated microorganism. Globally, from 3% to 10% of the human population is attacked by ony cho mycosis, and many cases involve toenails. The aim of this work was to determine the minimal inhibitory concentrations (MICs) of antifungal drugs (fluconazole, ketoconazole, itraconazole, terbinafine, and griseofulvin) often used for the treatment of ungueal dermatophytosis caused by Trichophyton mentagrophytes.