Original Article

Ann Lab Med 2013; 33(3): 167-173

Published online May 1, 2013

Copyright © Korean Society for Laboratory Medicine.

In Vitro Fluconazole and Voriconazole Susceptibilities of Candida Bloodstream Isolates in Korea: Use of the CLSI and EUCAST Epidemiological Cutoff Values

Min Joong Jang, M.D.1, Jong Hee Shin, M.D.1, Wee Gyo Lee, M.D.2, Mi-Na Kim, M.D.3, Kyungwon Lee, M.D.4,
Hye Soo Lee, M.D.5, Mi-Kyung Lee, M.D.6, Chulhun L. Chang, M.D.7, Hee-Chang Jang, M.D.1, Eun Song Song, M.D.1,
Soo Hyun Kim, M.D.1, Myung-Geun Shin, M.D.1, Soon-Pal Suh, M.D.1, and Dong-Wook Ryang, M.D.1

Department of Laboratory Medicine1, Chonnam National University Medical School and Chonnam National University Hospital, Gwangju; Department of Laboratory Medicine2, Ajou University, Suwon; Department of Laboratory Medicine3, University of Ulsan College of Medicine and Asan Medical Center, Seoul; Department of Laboratory Medicine4, Yonsei University College of Medicine, Seoul; Department of Laboratory Medicine5, Chonbuk National University Medical School, Jeonju; Department of Laboratory Medicine6, Chung-Ang University College of Medicine, Seoul; Department of Laboratory Medicine7, Pusan National University College of Medicine, Busan, Korea

Correspondence to: Jong Hee Shin
Department of Laboratory Medicine, Chonnam National University Medical School, 671 Jebong-ro, Dong-gu, Gwangju 501-757, Korea
Tel: +82-62-220-5342
Fax: +82-62-224-2518

Received: August 27, 2012; Revised: October 24, 2012; Accepted: January 24, 2013

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background: At present, the clinical breakpoints (CBPs) of both fluconazole and voriconazole are available only for 3 common Candida species in the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methods. Epidemiological cutoff values (ECVs) were recently applied to both methods to detect the emergence of acquired resistance (i.e., non-wild-type isolates) among 5 common Candida species.
Methods: We performed a nationwide study to determine the fluconazole and voriconazole susceptibility of Candida bloodstream isolates (BSIs) using both the CLSI and EUCAST methods. A total of 423 BSIs of 5 Candida species were collected from 8 hospitals. The azole susceptibilities were assessed on the basis of the species-specific CBPs and ECVs.
Results: Of the 341 BSIs of 3 common Candida species (i.e., C. albicans, C. tropicalis, and C. parapsilosis), 0.3% and 0.9%, 0.0% and 1.5% of isolates were categorized as fluconazole and voriconazole resistant according to the CLSI and EUCAST CBPs, respectively. Of 423 total BSIs, 1.4% and 2.6% had fluconazole minimum inhibitory concentrations (MICs) exceeding the ECVs according to the CLSI and EUCAST, respectively; 1.0% and 2.1% had voriconazole MICs exceeding the ECVs according to the CLSI and EUCAST, respectively. Categorical agreement between the methods using ECVs was 98.3% for fluconazole and 98.3% for voriconazole.
Conclusions: The EUCAST and CLSI methods using ECVs provide highly concordant results. Moreover, non-wild-type isolates with possibly acquired azole resistance were rare among the BSIs of 5 common Candida species in Korea.

Keywords: Candida, Fluconazole, Voriconazole, EUCAST, CLSI, epidemiological cutoff value