Resistance rates of non-albicans Candida infections in Taiwan after the revision of 2012 Clinical and Laboratory Standards Institute breakpoints.

Abstract

PurposeIn 2012, the Clinical and Laboratory Standards Institute (CLSI) revised its breakpoints for drugs and species because of the increase in non-albicans Candida infections and their drug resistance. Following global trends, the non-albicans candidemia resistance rate has increased in Taiwan as well. To update the antifungal susceptibility of non-albicans candidemia isolates, we conducted a multicenter study using the revised break points.Patients and methodsPatients with non-albicans candidemia infections were identified at five tertiary hospitals in Taiwan from July 1, 2011, to June 30, 2014. The broth microdilution method using a Sensititre YeastOne system was performed for the determination of minimum inhibitory concentration (MIC). The susceptibility was interpreted based on the guidelines of the CLSI (CLSI M27-S4 and M27-S3).ResultsCandida tropicalis was the predominant non-albicans candidemia pathogen (42.4%), and it showed increased fluconazole non-susceptibility (36.3%) when compared to the results from previous studies. In particular, C. tropicalis showed high cross-resistance to azole agents. C. tropicalis isolates that were found to be resistant to fluconazole also showed increased resistance to voriconazole (82.2%) and posaconazole (100%). The increased non-susceptibility of Candida glabrata to multiple antifungal agents, based on the revised break points, resulted from an increase in dose-dependent susceptibility (94.4%) rather than from an increase in resistance (5.6%).ConclusionThe resistance rate of non-albicans candidemia isolates is increasing, particularly for C. tropicalis and C. glabrata.