Determination of Resistance Rates of Candida albicans Species Isolated from Sterile Body Fluids to Triazoles by Microdilution Method

Abstract

Aim: Widespread and repeated use of azoles for prophylaxis or therapy has led to the development of resistance in Candida albicans species. In this study, it was aimed to determine the in vitro resistance rates of Candida albicans isolates isolated from sterile body fluid cultures to fluconazole, itroconazole and voriconazole. Material and Methods: Candida albicans species isolated from sterile body fluid cultures sent from various clinics between January 2020 and April 2021 were included in the study. Species-level identification was assessed using conventional methods and the BD Phoenix 100 (BD, USA) automated identification system. Antifungal susceptibility testing was performed by microdilution method using RPMI medium containing 2 % glucose according to EUCAST recommendations. For the triazoles fluconazole, itroconazole and voriconazole, the concentration in the well at which turbidity was reduced significantly (≥50%) was determined as the MIC50 value. C.albicans ATCC 90028 was used as control strain. Results: It was found that 51/99 (51.5%) of the candidemia agents were Candida albicans. 88.2% (n=45) of Candida albicans isolates were isolated from samples taken from intensive care units.Twenty-six (50.9%) of the samples were taken from female patients with a mean age of 68.6 ± 18.29 years, and 25 (49%) from male patients with a mean age of 62.22 ± 21.08 years. One (1.9 %) of the isolates were identified from cerebrospinal fluid, 1 (1.9 %) sterile body fluid, 1 (1.9 %) bronchoalveolar lavage, and 48 (94.1%) blood cultures. According to the antifungal susceptibility test results; 7 (12.2 %) of the species were resistant to fluconazole, 14 (27.4 %) to itroconazole, and 2 (3.9%) to 5 (9.8 %) voriconazole. Cross-resistance was detected in a total of 6 (11.7 %) samples. Conclusion: C. albicans is still the most frequently isolated species among the candidemia agents detected in our hospital. Cross-resistance to other triazoles was observed along with azole resistance. Therefore, antifungal susceptibility test results should be taken into account for appropriate treatment.