Sporothrix schenckii sensitivity to voriconazole, itraconazole and amphotericin B

One hundred clinical isolates of Sporothrix schenckii were tested against voriconazole, itraconazole and amphotericin B using a modification of the NCCLS M27-A in vitro yeast susceptibility testing procedure. NCCLS M38-P for moulds was not used because yeast forms may have been present when the test isolates were incubated at 35 +/- 1 degrees C. The minimum inhibitory concentration (MIC) values were: voriconazole 0.5-8 (geometric mean titer 6.50) microg ml(-1) ; itraconazole 0.03-8 (geometric mean titer 1.56) microg ml(-1); and amphotericin B 0.25-2 (geometric mean titer 1.23) microg ml(-1). The minimum fungicidal concentration (MFC) values were: voriconazole 2-8 (geometric mean titer 7.67) microg ml(-1); itraconazole 0.125-8 (geometric mean titer 7.41) microg ml(-1); and amphotericin B 0.125-2 (geometric mean titer 1.53) microg ml(-1). Based upon MIC values, sensitivity to amphotericin B is strain-dependent. S. schenckii is more sensitive to itraconazole than voriconazole based upon a comparison of MIC geometric means, even though the MIC ranges were essentially the same.