Resumo

Candida yeasts are the main fungal pathogens involved in human infections. Due to the increased propensity of these yeasts to antimicrobial resistance, studies are needed to assess a possible change in the sensitivity profile. In this study we analysed a total of 102 Candida spp isolates from blood cultures of patients admitted at the Hospital Universitário de Londrina between the years 2006-2007 and 2010-2011. The reference strains ATCC 22019 and ATCC 6258 were used as controls. The antifungal activity was performed by determining the Minimum Inhibitory Concentration (MIC) by broth microdilution technique defined by AFST-EUCAST, 2008. The antifungal agents used in susceptibility tests were amphotericin B, fluconazole, itraconazole and voriconazole. Regarding the antifungal amphotericin B, only one isolate of C. albicans was resistant (0.98%) among all strains tested. Concerning the antifungal fluconazole, high MICs (16 μg/ml-32 μg/ml) were found for 90% of C. glabrata isolates. The frequency of resistance among isolates of C. parapsilosis was 30.4%, while it was only 3.7% for C. albicans and 3.2% for C. tropicalis. Resistance was uncommon with respect to antifungal voriconazole among isolates of C. albicans (3.7%) and C. tropicalis (3.2%). Regarding the C. parapsilosis was not found resistance of voriconazole. However, MICs greater than 0.125 μg/ml were common among C. glabrata (90%) and C. krusei (100%). The isolates of C. glabrata and C.krusei that showed high MICs for voriconazole also presented MICs to fluconazole. This phenomenon also occurred for isolates of C. albicans and C. tropicalis, indicating cross-resistance to azoles. Concerning the antifungal itraconazole, MIC50 of 0.03 μg/ml was observed for isolates of C. albicans, C. tropicalis and C. parapsilosis. On the other hand, for C. krusei and C. glabrata the MIC50 values were higher, being 0.125 μg/ml-0,25 μg/ml and 0.5 μg/ml, respectively. Among the studied antifungal, amphotericin B showed better results against the Candida isolates tested. The isolates of C. krusei and C. glabrata needs a special attention in the treatment selection due the high MICs found.