Identification of fungal clinical isolates by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry

Rev Esp Quimioter. 2013 Sep;26(3):193-7.

Abstract

Background: Recently, bacterial identification by MALDI-TOF MS has acquired a high relevance in terms of speed and reliability. Conventional mycological identification has some disadvantages: it is frequently slow, reliability is sometimes low, and an extensive experience is required. The risk population for fungal infections, and therefore their clinical significance has progressively increased in recent years.

Methods: 153 yeast and mould clinical isolates were analyzed by MALDI-TOF MS and conventional identification. When both methods were discrepant to the genus or species level, ITS-2 sequencing was performed. Results. The correlation in yeasts identification between conventional identification methods and MALDI-TOF MS was extremely high (99.2% to the species level and 100% to the genus level). The only discrepancy was checked by ITS-2 sequencing and confirmed the MALDI-TOF identification. The correlation in moulds identification was more heterogeneous. 68.7% of the isolates showed correlation at least to the genus level and 40.6% to the species level. Therefore, the correlation between conventional identification and MALDI-TOF MS in fungal identification was, in whole, 87% to the species level, and 93.5% to the genus level.

Conclusions: Identification of fungi by MALDI-TOF MS is reliable and shows potential advantages over conventional identification methods.

MeSH terms

  • Data Interpretation, Statistical
  • Fungi / chemistry*
  • Humans
  • Microbiological Techniques
  • Mycoses / microbiology*
  • Reproducibility of Results
  • Species Specificity
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Yeasts / chemistry