title: MALDI-TOF MS-based identification of black yeasts of the genus Exophiala.
abstract: In this study, we investigated the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of Exophiala species. The analysis included a total of 110 Exophiala isolates, including 15 CBS strains representing 4 species, Exophiala dermatitidis (61), E. phaeomuriformis (36), E. crusticola (9), and E. heteromorpha (4), that had been previously identified based on internal transcribed spacer (ITS) regions. We also compared the relative efficacies of Sabouraud glucose agar (SGA) and Columbia agar (CA) for use in MALDI-TOF MS. Remarkably, we obtained a log-score value ≥2.0 by using either SGA or CA for all 15 CBS strains, indicating species-level identification. The remaining 95 Exophiala strains were identified to the genus or species levels, with identification rates of 96.8% and 90.5%, using SGA or CA, respectively. Most of the E. dermatitidis (100% and 92.9%), E. phaeomuriformis (80.6% and 83.9%), E. crusticola (50% and 100%), and E. heteromorpha (100% and 100%) isolates were correctly identified using SGA or CA, respectively. Furthermore, 58.9% and 26.3% of the strains had log-score values of ≥2.0 by using SGA and CA, respectively. Our results indicate that MALDI-TOF MS is a rapid and reliable technique with high rates of correct taxonomic identification.
authors: Department of Microbiology, Faculty of Medicine, University of Akdeniz, Antalya, Turkey.
authors: Betil
authors: B
authors: Özhak-Baysan
authors: Department of Microbiology, Faculty of Medicine, University of Akdeniz, Antalya, Turkey.
authors: Dilara
authors: D
authors: Öğünç
authors: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Mersin, Mersin, Turkey.
authors: Aylin
authors: A
authors: Döğen
authors: Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey milkit@cu.edu.tr.
authors: Macit
authors: M
authors: Ilkit
authors: CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands Research Center for Medical Mycology, Peking University Health Science Center, Beijing, China Sun Yat-sen Hospital, Sun Yat-sen University, Guangzhou, China Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China Basic Pathology Department, Federal University of Paraná State, Curitiba, Paraná, Brazil King Abdulaziz University, Jeddah, Saudi Arabia.
authors: G Sybren
authors: GS
authors: de Hoog
mesh_terms: D003470:Culture Media / Q000737:chemistry; D005093:Exophiala / Q000737:chemistry* / Q000166:cytology* / Q000254:growth & development; D008828:Microbiological Techniques / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013997:Time Factors
chemical_list: D003470:Culture Media
keywords: ITS sequencing; MALDI mass spectrometry; black yeasts; database; species