title: Antifungal Susceptibility Testing of Aspergillus spp. by Using a Composite Correlation Index (CCI)-Based Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Method Appears To Not Offer Benefit over Traditional Broth Microdilution Testing.
abstract: Aspergillusspp. cause serious invasive lung infections, andAspergillus fumigatusis the most commonly encountered clinically significant species. Voriconazole is considered to be the drug of choice for treatingA. fumigatusinfections; however, rising resistance rates have been reported. We evaluated a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for the differentiation between wild-type and non-wild-type isolates of 20Aspergillusspp. (including 2 isolates ofAspergillus ustusand 1 ofAspergillus calidoustusthat were used as controls due their intrinsic low azole susceptibility with respect to thein vitroresponse to voriconazole). At 30 and 48 h of incubation, there was complete agreement between Cyp51A sequence analysis, broth microdilution, and MALDI-TOF MS classification of isolates as wild type or non-wild type. In this proof-of-concept study, we demonstrated that MALDI-TOF MS can be used to accurately detectA. fumigatusstrains with reduced voriconazole susceptibility. However, rather than proving to be a rapid and simple method for antifungal susceptibility testing, this particular MS-based method showed no benefit over conventional testing methods.
authors.affiliation: Multi-Organ Transplant Unit, University Health Network, Toronto, ON, Canada.
authors.forename: Melissa R
authors.initials: MR
authors.lastname: Gitman
authors.affiliation: Public Health Ontario, Toronto, ON, Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: McTaggart
authors.affiliation: Public Health Ontario, Toronto, ON, Canada.
authors.forename: Joanna
authors.initials: J
authors.lastname: Spinato
authors.affiliation: Public Health Ontario, Toronto, ON, Canada.
authors.forename: Rahgavi
authors.initials: R
authors.lastname: Poopalarajah
authors.affiliation: Public Health Ontario, Toronto, ON, Canada.
authors.forename: Erin
authors.initials: E
authors.lastname: Lister
authors.affiliation: Multi-Organ Transplant Unit, University Health Network, Toronto, ON, Canada.|Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Shahid
authors.initials: S
authors.lastname: Husain
authors.affiliation: Public Health Ontario, Toronto, ON, Canada julianne.kus@oahpp.ca.|Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
authors.forename: Julianne V
authors.initials: JV
authors.lastname: Kus
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001230:Aspergillus / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D000075082:Proof of Concept Study; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D065819:Voriconazole / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D065819:Voriconazole
keywords: Aspergillus; MALDI-TOF MS; antifungal susceptibility testing; composite correlation index; voriconazole; voriconazole resistance