title: ATR-FTIR Spectroscopy Highlights the Problem of Distinguishing Between Exophiala dermatitidis and E. phaeomuriformis Using MALDI-TOF MS.
abstract: The present study compared two chemical-based methods, namely, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, to understand the misidentification of Exophiala dermatitidis and Exophiala phaeomuriformis. The study utilized 44 E. dermatitidis and 26 E. phaeomuriformis strains, which were partially treated with strong acids and bases for further evaluation. MALDI-TOF MS and ATR-FTIR spectroscopy data of the two Exophiala species were compared. Data groupings were observed for the chromic acid- and nitric acid-treated species when the black yeast sources were categorized as creosoted-oak sleepers, concrete sleepers, or dishwasher isolates. The MALDI-TOF MS data for the metalloenzyme-containing regions were consistent with the ATR-FTIR spectroscopy data. These results indicated that environmental isolates might contain metals not found in human isolates and might interfere with chemical-based identification methods. Therefore, MALDI-TOF MS reference libraries should be created for clinical strains and should exclude petroleum-associated environmental isolates.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey. cagri@pau.edu.tr.
authors.forename: Çağrı
authors.initials: Ç
authors.lastname: Ergin
authors.affiliation: Chemistry Department, Faculty of Science and Arts, Pamukkale University, Denizli, Turkey.
authors.forename: Yaşar
authors.initials: Y
authors.lastname: Gök
authors.affiliation: Chemistry Department, Faculty of Science and Arts, Pamukkale University, Denizli, Turkey.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Bayğu
authors.affiliation: Department of Microbiology, Gülhane Military Medical Academy, Ankara, Turkey.
authors.forename: Ramazan
authors.initials: R
authors.lastname: Gümral
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Akdeniz, Antalya, Turkey.
authors.forename: Betil
authors.initials: B
authors.lastname: Özhak-Baysan
authors.affiliation: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Mersin, Mersin, Turkey.
authors.forename: Aylin
authors.initials: A
authors.lastname: Döğen
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Akdeniz, Antalya, Turkey.
authors.forename: Dilara
authors.initials: D
authors.lastname: Öğünç
authors.affiliation: Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey.
authors.forename: Macit
authors.initials: M
authors.lastname: Ilkit
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.|Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.|Invasive Fungi Research Center, Mazandaran University Medical Center, Sari, Iran.
authors.forename: Seyedmojtaba
authors.initials: S
authors.lastname: Seyedmousavi
mesh_terms: D005093:Exophiala / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification; D006801:Humans; D016533:Mycological Typing Techniques / Q000379:methods*; D060446:Phaeohyphomycosis / Q000382:microbiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
keywords: Chemical analysis; MALDI mass spectrometry; Taxonomy; İdentification; İnfrared spectroscopy