Overestimation of Amphotericin B Resistance in Candida auris with Sensititre YeastOne Antifungal Susceptibility Testing: a Need for Adjustment for Correct Interpretation
Maria Siopi, Ilektra Peroukidou, Maria-Ioanna Beredaki, Bram Spruijtenburg, Theun de Groot, Jacques F. Meis, Georgia Vrioni, Athanasios Tsakris, Spyros Pournaras, Joseph Meletiadis
Abstract
Candida auris is an emerging and frequently multidrug-resistant fungal pathogen that accounts for life-threatening invasive infections and nosocomial outbreaks worldwide. Reliable AF is important for the choice of the optimal treatment. Commercial methods are frequently used without prior vigorous assessment. Resistance to AMB was over-reported with the commercial colorimetric method Sensititre YeastOne (SYO). SYO produced MICs that were 1 to 2 twofold dilutions higher than those of the reference CLSI method, resulting in 89% MaE. MaE were reduced using a SYO-specific colorimetric wild type upper limit MIC value of 8 mg/L (0%) or a 50% growth inhibition endpoint (3%).