SENSITIVITY OF YEAST ISOLATED FROM SURVEILLANCE SPECIMENS INPATIENT WITH HAEMATOLOGICAL MALIGNANCIES IN YEAR 1992–2005

Abstract

BACKGROUND Yeasts of the genus Candida are among the most frequent causative agents of opportunisticinfections. In the last decades, the increased incidence of fungal infections led to increasedconsumption of antifungal agents. Our study compared the sensitivity of Candidaalbicans and Candida glabrata isolated in two time periods 1992–1996 and 2003–2005.The aim of our study was to determine whether the sensitivity of yeasts changed due toincreased consumption of antifungal agents. METHODS All isolates were isolated from surveillance specimens of patients, hospitalized in the Departmentof Hematology, University Clinical Center Ljubljana. In all yeast isolates minimalinhibitory concentrations (MIC) of fluconazole, voriconazole, itraconazole and amphotericinB were determined using the E-test. Mann-Whitney’s U test was used for statisticalanalysis. RESULTS Statistical comparison generally indicated lower antifungal drug sensitivity of yeasts inyears 1992–1996, in comparison to the period 2003–2005. MICs of all tested antifungalagents in C. albicans isolates were higher in years 1992–1996. Differences in MICs ofitraconazole and voriconazole were observed in C. glabrata isolates. MICs of itraconazolewere higher in years 1992–1996 and MICs of voriconazole were higher in years 2003–2005. However, no statistically significant differences in MICs of fluconazole and amphotericinB were observed.We have also studied the influence of antifungal prophylactic therapy on MICs of antifungalagents. For C. albicans the influence was shown for fluconazole and amphotericin B,while we could not show any influence for C. glabrata, most probably due to low number ofisolates. CONCLUSIONS According to the results of our study, the hypothesis about decreased sensitivity of yeastsdue to increased consumption of antifungal agents in the last decades was rejected