Candida Species Distribution and Antifungal Susceptibility Testing According to EUCAST and New vs. Old CLSI Clinical Breakpoints: a Six-Year Prospective Candidemia Survey from the Fungal Infection Network of Switzerland (FUNGINOS).

We analyzed the species distribution of Candida blood isolates (CBI), prospectively collected between 2004 and 2009 within FUNGINOS, and compared their antifungal susceptibility according to clinical breakpoints defined by: EUCAST in 2013, CLSI in 2008 (old CLSI breakpoints) and 2012 (new CLSI breakpoints). CBI were tested for susceptiblity to fluconazole, voriconazole and caspofungin by microtitre broth dilution (Sensititre(®) YeastOne(TM) test panel). Of 1090 CBI, 675 (61.9%) were C. albicans, 191 (17.5%) C. glabrata, 64 (5.9%) C. tropicalis, 59 (5.4%) C. parapsilosis, 33 (3%) C. dubliniensis, 22 (2%) C. krusei and 46 (4.2%) rare Candida species. Independently of the breakpoints applied, C. albicans was almost uniformely (>98%) susceptible to all 3 antifungal agents. In contrast, the proportions of fluconazole- and voriconazole- susceptible C. tropicalis and F-susceptible C. parapsilosis were lower according to EUCAST/new CLSI breakpoints than to the old CLSI breakpoints. For caspofungin, non-susceptibility occurred mainly in C. krusei (63.3%) and C. glabrata (9.4%). Nine isolates (5 C. tropicalis, 3 C. albicans, 1 C. parapsilosis) were cross-resistant to azoles according to EUCAST breakpoints compared to 3 isolates (2 C. albicans, 1 C. tropicalis) according to new and 2 (2 C. albicans) to old CLSI breakpoints. Four species (C. albicans, C. glabrata, C. tropicalis, C. parapsilosis) represented >90% of all CBI. In vitro resistance to fluconazole, voriconazole and caspofungin was rare among C. albicans, but an increase of non-susceptibile isolates was observed among C. tropicalis/C. parapsilosis for the azoles and C. glabrata/C. krusei for caspofungin according to EUCAST and new CLSI breakpoints compared to old CLSI breakpoints. This article is protected by copyright. All rights reserved