title: Evaluation of disk diffusion method compared to broth microdilution for antifungal susceptibility testing of 3 echinocandins against Aspergillus spp.
abstract: We tested the susceptibility of caspofungin, micafungin, and anidulafungin against Aspergillus spp. isolates by the new Clinical and Laboratory Standards Institute M51-A disk diffusion (DD) and the broth microdilution methods. A total of 65 clinical isolates of Aspergillus spp. were evaluated. The DD assay was performed on nonsupplemented Müeller-Hinton agar using caspofungin 2-μg, micafungin 1-μg, and anidulafungin 2-μg disks. Echinocandin minimal effective concentrations (MECs) and inhibition zones (IZs) were read after 24 to 48 (A. terreus) h at 35 °C. Caspofungin MECs for all Aspergillus spp. strains tested were ≤ 0.25 μg/mL; IZs were ≥ 15 mm for most species except for A. terreus (11-22 mm). Both micafungin and anidulafungin MECs were ≤ 0.015 μg/mL, but micafungin IZs were ≥ 14 mm while anidulafungin IZs were ≥ 22 mm. As for caspofungin, the DD method could be a useful method for susceptibility testing of micafungin and anidulafungin against Aspergillus spp.
authors.affiliation: Microbiology Service, Valme University Hospital, Seville, Spain. aisabel_martos@hotmail.com
authors.forename: Antonia Isabel
authors.initials: AI
authors.lastname: Martos
authors.forename: Estrella
authors.initials: E
authors.lastname: Martín-Mazuelos
authors.forename: Ana
authors.initials: A
authors.lastname: Romero
authors.forename: Carmen
authors.initials: C
authors.lastname: Serrano
authors.forename: Trinidad
authors.initials: T
authors.lastname: González
authors.forename: Carmen
authors.initials: C
authors.lastname: Almeida
authors.forename: Beatriz
authors.initials: B
authors.lastname: Puche
authors.forename: Emilia
authors.initials: E
authors.lastname: Cantón
authors.forename: Javier
authors.initials: J
authors.lastname: Pemán
authors.forename: Ana
authors.initials: A
authors.lastname: Espinel-Ingroff
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001228:Aspergillosis / Q000382:microbiology; D001230:Aspergillus / Q000187:drug effects* / Q000302:isolation & purification; D003470:Culture Media / Q000737:chemistry; D054714:Echinocandins / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods
chemical_list: D000935:Antifungal Agents; D003470:Culture Media; D054714:Echinocandins