Antifungal Resistance to Fluconazole and Echinocandins Is Not Emerging in Yeast Isolates Causing Fungemia in a Spanish Tertiary

Accurate knowledge of fungemia epidemiology requires identification of strains to the molecular level. Various studies have shown that the rate of resistance to fluconazole ranges from 2.5 % to 9 % in Candida spp. isolated from blood samples. However, trends in antifungal resistance have received little attention and have been studied only using CLSI M27-A3methodology. We assessed the fungemia epidemiology in a large tertiary care institution inMadrid, Spain, by identifying isolates to the molecular level and performing antifungal susceptibility testing according to the updated breakpoints of European Committee for Antimi-crobial Susceptibility Testing (EUCAST) definitive document (EDef) 7.2. We studied 613 isolates causing 598 episodes of funge-mia in 544 patients admitted to our hospital (January 2007 to December 2013). Strains were identified after amplification and sequencing of the ITS1-5.8S-ITS2 region and further tested for in vitro susceptibility to amphotericin B, fluconazole, posacona-zole, voriconazole, micafungin, and anidulafungin. Resistance was defined using EUCAST species-specific breakpoints, and epi-demiological cutoff values (ECOFFs) were applied as tentative breakpoints. Most episodes were caused by Candida albicans (46%), Candida parapsilosis (28.7%), Candida glabrata (9.8%), and Candida tropicalis (8%). Molecular identification enabled us to better detect cryptic species of Candida guilliermondii and C. parapsilosis complexes and episodes of polyfungal fungemia. The overall percentage of fluconazole-resistant isolates was 5%, although it was higher in C. glabrata (8.6%) and non-Candida yeast isolates (47.4%). The rate of resistance to echinocandins was 4.4 % and was mainly due to the presence of intrinsically resis