PLOS ONE, 2015, 01, 1─9

Antifungal Susceptibilities of Bloodstream Isolates of Candida Species from Nine Hospitals in Korea: Application of New Antifungal Breakpoints and Relationship to Antifungal Usage

EunJeong Won, J Shin, M Choi, W Lee, Y Park, Y Uh

Abstract

We applied the new clinical breakpoints (CBPs) of the Clinical and Laboratory Standards Institute (CLSI) to a multicenter study to determine the antifungal susceptibility of bloodstream infection (BSI) isolates of Candida species in Korea, and determined the relationship between the frequency of antifungal-resistant Candida BSI isolates and antifungal use at hospitals. Four hundred and fifty BSI isolates of Candida species were collected over a 1-year period in 2011 from nine hospitals. The susceptibilities of the isolates to four antifungal agents were determined using the CLSI M27 broth microdilution method. By applying the species-specific CBPs, non-susceptibility to fluconazole was found in 16.4%(70/428) of isolates, comprising 2.6% resistant and 13.8%susceptible-dose dependent isolates. However, non-susceptibility to voriconazole, caspofungin, or micafungin was found in 0%(0/370), 0%(0/437), or 0.5% (2/437) of the Candida BSI isolates, respectively. Of the 450 isolates, 72 (16.0%) showed decreased susceptibility to fluconazole [minimum inhibitory concentration (MIC) 4 μg/ml]. The total usage of systemic antifungals varied considerably among the hospitals, ranging from 190.0 to 7.7 defined daily dose per 1,000 patient days, and fluconazole was the most commonly prescribed agent (46.3%). By Spearman’s correlation analysis, fluconazole usage did not show a significant correlation with the percentage of fluconazole resistant isolates at hospitals. However, fluconazole usage was significantly correlated with the percentage of fluconazole non-susceptible isolates (r = 0.733; P = 0.025) or the percentage of isolates with decreased susceptibility to fluconazole (MIC 4 μg/ml) (r = 0.700; P = 0.036) at hospitals. Our work represents the first South Korean multicenter study demonstrating an association

• ISBN or ISSN: 1932-6263

• 본 연구는 질병관리본부 연구개발과제(과제번호 2013-E44001-00) 연구비를 지원받아 수행되었습니다.
• This research was supported by a fund(code 2013-E44001-00) by Research of Korea Centers for Disease Control and Prevention.