title: Multicenter study of anidulafungin and micafungin MIC distributions and epidemiological cutoff values for eight Candida species and the CLSI M27-A3 broth microdilution method.
abstract: Since epidemiological cutoff values (ECVs) using CLSI MICs from multiple laboratories are not available for Candida spp. and the echinocandins, we established ECVs for anidulafungin and micafungin on the basis of wild-type (WT) MIC distributions (for organisms in a species-drug combination with no detectable acquired resistance mechanisms) for 8,210 Candida albicans, 3,102 C. glabrata, 3,976 C. parapsilosis, 2,042 C. tropicalis, 617 C. krusei, 258 C. lusitaniae, 234 C. guilliermondii, and 131 C. dubliniensis isolates. CLSI broth microdilution MIC data gathered from 15 different laboratories in Canada, Europe, Mexico, Peru, and the United States were aggregated to statistically define ECVs. ECVs encompassing 97.5% of the statistically modeled population for anidulafungin and micafungin were, respectively, 0.12 and 0.03 μg/ml for C. albicans, 0.12 and 0.03 μg/ml for C. glabrata, 8 and 4 μg/ml for C. parapsilosis, 0.12 and 0.06 μg/ml for C. tropicalis, 0.25 and 0.25 μg/ml for C. krusei, 1 and 0.5 μg/ml for C. lusitaniae, 8 and 2 μg/ml for C. guilliermondii, and 0.12 and 0.12 μg/ml for C. dubliniensis. Previously reported single and multicenter ECVs defined in the present study were quite similar or within 1 2-fold dilution of each other. For a collection of 230 WT isolates (no fks mutations) and 51 isolates with fks mutations, the species-specific ECVs for anidulafungin and micafungin correctly classified 47 (92.2%) and 51 (100%) of the fks mutants, respectively, as non-WT strains. These ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin and micafungin due to fks mutations.
authors.affiliation: JMI Laboratories, North Liberty, Iowa, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Pfaller
authors.forename: A
authors.initials: A
authors.lastname: Espinel-Ingroff
authors.forename: B
authors.initials: B
authors.lastname: Bustamante
authors.forename: E
authors.initials: E
authors.lastname: Canton
authors.forename: D J
authors.initials: DJ
authors.lastname: Diekema
authors.forename: A
authors.initials: A
authors.lastname: Fothergill
authors.forename: J
authors.initials: J
authors.lastname: Fuller
authors.forename: G M
authors.initials: GM
authors.lastname: Gonzalez
authors.forename: J
authors.initials: J
authors.lastname: Guarro
authors.forename: C
authors.initials: C
authors.lastname: Lass-Flörl
authors.forename: S R
authors.initials: SR
authors.lastname: Lockhart
authors.forename: E
authors.initials: E
authors.lastname: Martin-Mazuelos
authors.forename: J F
authors.initials: JF
authors.lastname: Meis
authors.forename: L
authors.initials: L
authors.lastname: Ostrosky-Zeichner
authors.forename: T
authors.initials: T
authors.lastname: Pelaez
authors.forename: G
authors.initials: G
authors.lastname: St-Germain
authors.forename: J
authors.initials: J
authors.lastname: Turnidge
mesh_terms: D000077612:Anidulafungin; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D002177:Candidiasis / Q000453:epidemiology / Q000382:microbiology; D054714:Echinocandins / Q000494:pharmacology*; D005060:Europe / Q000453:epidemiology; D005656:Fungal Proteins / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D055666:Lipopeptides / Q000494:pharmacology*; D000077551:Micafungin; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009656:North America / Q000453:epidemiology; D013020:South America / Q000453:epidemiology
chemical_list: D000935:Antifungal Agents; D054714:Echinocandins; D005656:Fungal Proteins; D055666:Lipopeptides; D000077612:Anidulafungin; D000077551:Micafungin