In vitro susceptibility of isolates of Sporothrix schenckii to terbinafine and itraconazole

Abstract

The study objective was to determine the in vitro activity of terbinafine and itraconazole through the microdilution technique in broth (NCCLSM27-A2), adapted for dimorphic fungus, in relation to 12 isolates of Sporothrix schenckii. Six were from feline sporotrichosis, three from human sporotrichosis, one from a dog and two from human isolates originating from Instituto Oswaldo Cruz. The inoculum and antifungal concentrates were distributed on microplates that were incubated at 35°C for five days. Minimum inhibitory concentration readings were made at the end of this period. The MIC for terbinafine ranged from 0.055µg/ml to 0.109µg/ml, and the MIC for itraconazole ranged from 0.219µg/ml to 1.75µg/ml. For both drugs, the MIC from the isolates from IOC was 0.875µg/ml. The present study demonstrates the high susceptibility of Sporothrix schenckii to terbinafine. Further studies to correlate the in vitro susceptibility tests with the clinical response of patients with sporotrichosis are needed.

Sporothrix schenckii; Susceptibility; Terbinafine; Itraconazole