Oral Candida albicans isolates with reduced susceptibility to fluconazole in Swedish HIV-infected patients

A total of 62 patients with HIV-related conditions were examined for clinical and mycological oral findings. Cultures from 51 patients were positive for yeasts and included 49 Candida albicans and 8 non-albicans isolates. Of patients with positive culture, 35% had pseudomembranous thrush. In vitro susceptibility testing of 49 C. albicans isolates revealed that the minimal inhibitory concentration for 50% of the strains (MIC50) was 2.0 mg/l for fluconazole, and the MIC50 was < or = 0.125 mg/l for both ketoconazole and itraconazole. Fluconazole resistance (MIC > or = 32.0 mg/l) was found for 14% of the C. albicans isolates tested. Two C. albicans isolates showed cross-resistance to ketoconazole and itraconazole. Associations between reduced susceptibility to fluconazole and low CD4+ cell counts, the length of time since the first AIDS-defining illness and the interval from the first fluconazole treatment, indirectly reflecting the total fluconazole exposure, were observed.