The presence of fluconazole-resistant Candida dubliniensis strains among Candida albicans isolates from immunocompromised or otherwise debilitated HIV-negative Turkish patients.

The newly described species Candida dubliniensis phenotypically resembles Candida albicans in many respects and so it could be easily misidentified. The present study aimed at determining the frequency at which this new Candida species was not recognized in the authors’ university hospital clinical laboratory and to assess antifungal susceptibility. In this study six identification methods based on significant phenotypic characteristics each proposed as reliable tests applicable in mycology laboratories for the differentiation of the two species were performed together to assess the clinical strains that were initially identified as C. albicans. Only the isolates which have had the parallel results in all methods were assessed as C. dubliniensis. One hundred and twentynine C. albicans strains isolated from deep mycosis suspected patients were further examined. Three of 129 C. albicans ( two from oral cavity, one from sputum) were reidentified as C. dubliniensis. One of the strains isolated from oral cavity and that from sputum were obtained at two months intervals from the same patient with acute myeloid leukemia, while the other oral cavity strain was obtained from a patient who had previously been irradiated for a laryngeal malignancy. Isolates were all susceptible in vitro to amphotericin B, with the MIC range 0.125 to 0.5 µg/ml, resistant to fluconazole, with the MICs ≥ 64 µg/ml, and resistant to ketoconazole, with the MICs ≥ 16 µg/ml, dose-dependent to itraconazole with the MIC range 0.25-0.5 µg/ml, and susceptible to flucytosine, with the MIC range 1-4 µg/ml.