title: Comparison of disk diffusion, E-test and broth microdilution test in determination of susceptibility of Aspergillus species to amphotericin B, itraconazole and voriconazole.
abstract: In response to the recent increase in Aspergillus infections, new antifungal agents have become available accompanied by studies on antifungal susceptibility tests for epidemiological follow-up. The aim of this study was to compare the efficacy of Clinical Laboratory Standards Institute (CLSI) M 38-A broth microdilution test with the disk diffusion and E-test in determining the susceptibility of Aspergillus spp. to amphotericin B, itraconazole and voriconazole. The study was carried out on 18 A. fumigatus, 7 A. flavus, 5 A. niger and 2 A. versicolor strains isolated from clinical samples. The microdilution method was performed by following the instructions of CLSI M 38-A. The E-test and disk diffusion tests were performed according to the instructions of their manufacturers. The percent agreement between the E-test and CLSI M38-A broth microdilution test at 24 (48) h within +/- 2 dilutions was, respectively, 81% (69%) for amphotericin B, 75% (72%) for itraconazole and 85% (81%) for voriconazole. The disk diffusion test showed good correlation with the E-test but poor correlation with the broth microdilution test for the three antifungal agents we tested. In conclusion, E-test and disk diffusion test have their advantages such as ease of application and interpretation, but their correlation with the broth microdilution should be improved.
authors.affiliation: Dokuz Eylul University School of Medicine, Department of Infectious Disease and Clinical Microbiology, Izmur, Turkey. aydan.ozkutuk@deu.edu.tr
authors.forename: A
authors.initials: A
authors.lastname: Ozkutuk
authors.forename: C
authors.initials: C
authors.lastname: Ergon
authors.forename: D Y
authors.initials: DY
authors.lastname: Metin
authors.forename: M
authors.initials: M
authors.lastname: Yucesoy
authors.forename: S H
authors.initials: SH
authors.lastname: Polat
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D001230:Aspergillus / Q000187:drug effects* / Q000302:isolation & purification; D052978:Disk Diffusion Antimicrobial Tests; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D011743:Pyrimidines / Q000494:pharmacology*; D014230:Triazoles / Q000494:pharmacology*; D065819:Voriconazole
chemical_list: D000935:Antifungal Agents; D011743:Pyrimidines; D014230:Triazoles; D017964:Itraconazole; D000666:Amphotericin B; D065819:Voriconazole