Antifungal resistance to fluconazole and echinocandins is not emerging in yeast isolates causing fungemia in a Spanish tertiary care center.

Antifungal resistance to fluconazole and echinocandins is not emerging in yeast isolates causing fungemia in a Spanish tertiary care center.

Antimicrob Agents Chemother. 2014 May 27;

Authors: Marcos-Zambrano LJ, Escribano P, Sánchez C, Muñoz P, Bouza E, Guinea J

Abstract
Accurate knowledge of the fungemia epidemiology requires identification of strains to 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 only been studied using CLSI M27-A3 methodology. We assessed the fungemia epidemiology in a large tertiary institution in Madrid, Spain by identifying isolates to molecular level and performing antifungal susceptibility testing according to the updated breakpoints of EUCAST EDEF 7.2. We studied 613 isolates causing 598 episodes of fungemia 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, posaconazole, voriconazole, micafungin, and anidulafungin. Resistance was defined using EUCAST species-specific breakpoints, and ECOFFs were applied as tentative breakpoints. Most episodes were caused by C. albicans (46%), C. parapsilosis (28.7%), C. glabrata (9.8%), and C. tropicalis (8%). Molecular identification enabled us to better detect cryptic species of C. guilliermondii and C. parapsilosis complexes and episodes of polyfungal fungemia. The overall percentage of fluconazole-resistant isolates was 5%, although this 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 resistant non-Candida species. Resistance mainly affected non-Candida yeasts. The rate of resistance to fluconazole and echinocandins did not change considerably during the study period.

PMID: 24867979 [PubMed - as supplied by publisher]