title: Colorimetric assay for antifungal susceptibility testing of Aspergillus species.
abstract: A colorimetric assay for antifungal susceptibility testing of Aspergillus species (Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus nidulans, and Aspergillus ustus) is described based on the reduction of the tetrazolium salt 2,3-bis(2-methoxy-4-nitro-5-[(sulphenylamino)carbonyl]-2H-tetrazolium-hydroxide (XTT) in the presence of menadione as an electron-coupling agent. The combination of 200 microg of XTT/ml with 25 microM menadione resulted in a high production of formazan within 2 h of exposure, allowing the detection of hyphae formed by low inocula of 10(2) CFU/ml after 24 h of incubation. Under these settings, the formazan production correlated linearly with the fungal biomass and less-variable concentration effect curves for amphotericin B and itraconazole were obtained.
authors.affiliation: Department of Medical Microbiology, University Medical Center Nijmegen, Nijmegen, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Meletiadis
authors.forename: J W
authors.initials: JW
authors.lastname: Mouton
authors.forename: J F
authors.initials: JF
authors.lastname: Meis
authors.forename: B A
authors.initials: BA
authors.lastname: Bouman
authors.forename: J P
authors.initials: JP
authors.lastname: Donnelly
authors.forename: P E
authors.initials: PE
authors.lastname: Verweij
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001228:Aspergillosis / Q000382:microbiology; D001230:Aspergillus / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D003124:Colorimetry / Q000379:methods; D006801:Humans; D007202:Indicators and Reagents / Q000378:metabolism*; D008826:Microbial Sensitivity Tests / Q000379:methods; D013778:Tetrazolium Salts / Q000378:metabolism*; D024483:Vitamin K 3 / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D007202:Indicators and Reagents; D013778:Tetrazolium Salts; C059087:2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide; D024483:Vitamin K 3