Antifungal susceptibility evaluation of Candida albicans isolated from buccal lesions of hiv-positive and HIV-negative patients

The antifungal minimal inhibitory concentrations (MIC) were determined to 35 samples of Candida albicans; 14 of them were isolated from HIV-positive patients, and 21 from HIV-negative patients with oral erythematous candidosis. The aim of this study was to evaluate the performance of agar dilution method in the determination of susceptibility of Candida albicans isolated from buccal lesions of HIV-positive and negative patients to some antifungals and compare the results with the plasmatic concentration reached by each one of these drugs. The samples were evaluated in vitro by the agar dilution method and showed higher MIC values to ketoconazole, fluconazole, itraconazole and amphotericin B than the concentrations achieved by these antifungals in plasma. 88.9% of the samples presented in vitro resistance to ketoconazole and the plasmatic levels of this antifungal varied from 1 to 8 μg/mL. Regarding fluconazole and itraconazole, most samples presented MIC larger than 128 μg/mL and plasmatic concentration varying from 0.4 to 8 μg/mL. Only 11.9% of the samples were susceptible in vitro to fluconazole and 2.7% of them to itraconazol. The usage concentrations prescribed for the topical antifungals nystatin, fenticonazole and miconazole are markedly higher than the values of MIC obtained. Related to nystatin, it was verified that its MIC values were between 1 and 4 μg /mL. The plasmatic levels to this drug are extremely low. Fenticonazole presented a MIC value larger than 128 μg/mL. Relating to miconazole, the plasmatic levels vary from 1 to 8 μg/mL and 11.9% of the samples presented in vitro susceptibility to this drug. No significant differences (p<0.05) were found in the susceptibility profiles of the samples obtained from HIV-positive and HIV-negative patients.