Evaluation of the E test for fluconazole susceptibility testing of Candida albicans isolates from oropharyngeal candidiasis

The aim of the present study was to evaluate the utility of the E test in determining the antifungal susceptibility of Candida albicans, Reproducibility of the E test was determined for amphotericin B, fluconazole, and itraconazole using three different solid media: RPMI 1640, Casitone, and yeast nitrogen base agar, Minimum inhibitory concentrations (MICs) were comparable (results at +/-2 dilutions) in 92% of the tests for amphotericin B and in 100% for fluconazole and itraconazole, Determination of MIC endpoints was easiest on Casitone agar, Candida albicans isolates from 23 patients undergoing fluconazole therapy for oropharyngeal candidiasis were tested for fluconazole susceptibility, Good correlation was obtained between the MICs of fluconazole and clinical outcome, Clinical failure was associated with strains for which MICs were greater than or equal to 48 mu g/ml. These results suggest that the E test has potential utility for fluconazole susceptibility testing of clinical yeast isolates.