Susceptibility of Candida albicans blood isolates to 3 antifungal drugs: retrospective study in Rio Grande do Sul, Brazil, 1999-2009]

Background: Candidiasis is one of the most important among recurrent invasive yeast infections in patients, thus antifungal treatment becomes a challenge. Aims: The aim of this study was to evaluate the in vitro activity of clinical Candida albicans isolates from blood cultures to fluconazole, amphotericin B and anidulafungin, in a hospital from Rio Grande do Sul, Brazil. Methods: The susceptibility of 153 isolates to the 3 drugs mentioned was tested according to Clinical and Laboratory Standars Institute. Minimal inhibitory and fungicidal concentrations (MIC, MFC, respectively) of each drug were determined, as well as the epidemiological cutoff value (ECV). Results: All of the isolates were susceptible to anidulafungin, MIC and MFC <= 1 mu g/ml; however, when compared with ECV, 3% of the isolates exhibited higher values against fluconazole, 96% were susceptible, 3% susceptible dose-dependent, and 1% resistant. Also, it was observed that 21% of the isolates exhibited higher values than ECV. One isolate was resistant to amphotericin B; the other ones, susceptible, based on the MFC; furthermore, 1.5% of the isolates exhibited higher values. Conclusions: C albicans isolates exhibited more susceptibility to anidulafungin, and 90% of them (MIC90) exhibited the lowest values against amphotericin B. Based on ECV and Pfaller classification, isolates could be resistant to fluconazole, demonstrating the importance of the combination of these parameters. (C) 2012 Revista Iberoamericana de Micologia. Published by Elsevier Espana, S.L. All rights reserved.