ATR-FTIR Spectroscopy Highlights the Problem of Distinguishing Between Exophiala dermatitidis and E-phaeomuriformis Using MALDI-TOF MS

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Ergin C., Gok Y., Baygu Y., GUMRAL R., Ozhak-Baysan B., Dogen A., ...More

MICROBIAL ECOLOGY, vol.71, no.2, pp.339-346, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 71 Issue: 2
  • Publication Date: 2016
  • Doi Number: 10.1007/s00248-015-0670-z
  • Journal Name: MICROBIAL ECOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.339-346
  • Keywords: Chemical analysis, Identification, Infrared spectroscopy, MALDI mass spectrometry, Taxonomy, MASS-SPECTROMETRY, RAPID IDENTIFICATION, BLACK YEASTS, FUNGI, CREOSOTE, TIME, ENVIRONMENTS, HYDROCARBONS, PROTEINS, TURKEY
  • Çukurova University Affiliated: Yes

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.