Ann Lab Med.  2013 May;33(3):167-173. 10.3343/alm.2013.33.3.167.

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

• Jang MJ
• Shin JH
• Lee WG
• Kim MN
• Lee K
• Lee HS
• Lee MK
• Chang CL
• Jang HC
• Song ES
• Kim SH
• Shin MG
• Suh SP
• Ryang DW

• KMID: 1781321
• DOI: http://doi.org/10.3343/alm.2013.33.3.167

Abstract

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.

Keyword

Candida; Fluconazole; Voriconazole; EUCAST; CLSI; epidemiological cutoff value

MeSH Terms

Antifungal Agents/*pharmacology
Candida/*drug effects/isolation & purification
Candidiasis/epidemiology/microbiology
Drug Resistance, Fungal/drug effects
Fluconazole/*pharmacology
Humans
Microbial Sensitivity Tests
Pyrimidines/*pharmacology
Republic of Korea
Triazoles/*pharmacology
Antifungal Agents
Pyrimidines
Triazoles
Fluconazole

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