Antifungal susceptibility of Candida species isolated from patients with candidemia in southern Taiwan, 2007-2012: impact of new antifungal breakpoints.

Abstract

The Clinical and Laboratory Standard Institute (CLSI) revised the clinical breakpoints (CBPs) for the azoles and echinocandins against Candida species in 2012. We aimed to report the epidemiology of candidemia and antifungal susceptibility of Candida species and evaluate the impact of new CBPs on antifungal susceptibility in our region. All blood isolates of Candida species were obtained from 2007 to 2012. The minimum inhibitory concentrations of fluconazole, voriconazole, echinocandins and flucytosine against Candida isolates were determined by Sensititre YeastOne system. Differences in susceptibility rates between the CBPs of previous and revised versions of CLSI were examined. Of 709 Candida isolates, the fluconazole-susceptible rate was 96.5% in Candida albicans, 85.8% in Candida tropicalis and 92.1% in Candida parapsilosis by the revised CBPs. Compared with the susceptibility results by previous CBPs, the marked reductions in susceptibility of C.albicans, C.tropicalis and C.parapsilosis to fluconazole, that of C.tropicalis and C.parapsilosis to voriconazole, that of C.tropicalis and Candida glabrata to anidulafungin and that of C.tropicalis, C.glabrata and Candida krusei to caspofungin by revised CBPs were found. In conclusion, Candida albicans and C.parapsilosis remain highly susceptible to fluconazole. The non-susceptible rates of Candida species to azoles and echinocandins increase with interpretation by the revised CBPs.