Abstract
MALDI-TOF MS has become increasingly popular for microorganism identification in the routine laboratory. Compared with conventional morphology-based techniques, MALDI-TOF is relatively inexpensive (per-unit identification), involves a rapid result turnaround time and yields more accurate results without the need for highly qualified staff. However, this technology has been technically difficult to implement for filamentous fungi identification. Identification of dermatophytes, a type of filamentous fungi, remains particularly challenging, partly due to the lack of clear species definition for some taxa or within some species complexes. Review of the ten studies published between 2008 and 2015 shows that the accuracy of MALDI-TOF MS-based identification varied between 13.5 and 100 % for dermatophytes. This variability was partly due to inconsistencies concerning critical steps of the routine clinical laboratory process. Use of both a complete formic acid-acetonitrile protein extraction step and a manufacturer library supplemented with homemade reference spectra is essential for an accurate species identification. This technique is conversely unaffected by variations in other routine clinical laboratory conditions such as culture medium type, incubation time and type of mass spectrometry instrument. Provided that a reference spectra library is adequate for dermatophyte identification, MALDI-TOF MS identification is more economical and offers an accuracy comparable to that of DNA sequencing. The technique also represents an advantageous alternative to the protracted and labor-intensive dermatophyte identification via macroscopic and microscopic morphology in the routine clinical laboratory.
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Effendy I, Lecha M, Feuilhade de Chauvin M, Di Chiacchio N, Baran R. European onychomycosis observatory. Epidemiology and clinical classification of onychomycosis. J Eur Acad Dermatol Venereol. 2005;19(Suppl 1):8–12.
Gräser Y, Scott J, Summerbell R. The new species concept in dermatophytes-a polyphasic approach. Mycopathologia. 2008;166:239–56.
Kanbe T. Molecular approaches in the diagnosis of dermatophytosis. Mycopathologia. 2008;166:307–17.
Nenoff P, Erhard M, Simon JC, et al. MALDI-TOF mass spectrometry—a rapid method for the identification of dermatophyte species. Med Mycol. 2013;51:17–24.
Aluyi HA, Drucker DB. Fingerprinting of carbohydrates of Streptococcus mutans by combined gas–liquid chromatography–mass spectrometry. J Chromatogr. 1979;78:209–18.
Fisher-Hoch S, Hudson MJ, Thompson MH. Identification of a clinical isolate as Legionella pneumophila by gas chromatography and mass spectrometry of cellular fatty acids. Lancet. 1979;2:323–5.
Murray PR. What is new in clinical microbiology-microbial identification by MALDI-TOF mass spectrometry: a paper from the 2011 William Beaumont hospital symposium on molecular pathology. J Mol Diagn. 2012;14:419–23.
Fagerquist CK, Garbus BR, Miller WG, et al. Rapid identification of protein biomarkers of Escherichia coli O157:H7 by matrix-assisted laser desorption ionization-time-of-flight-time-of-flight mass spectrometry and top-down proteomics. Anal Chem. 2010;82:2717–25.
Erhard M, Hipler UC, Burmester A, Brakhage AA, Wöstemeyer J. Identification of dermatophyte species causing onychomycosis and tinea pedis by MALDI-TOF mass spectrometry. Exp Dermatol. 2008;17:356–61.
Amiri-Eliasi B, Fenselau C. Characterization of protein biomarkers desorbed by MALDI from whole fungal cells. Anal Chem. 2001;73:5228–31.
Marklein G, Josten M, Klanke U, et al. Matrix-assisted laser desorption ionization-time of flight mass spectrometry for fast and reliable identification of clinical yeast isolates. J Clin Microbiol. 2009;47:2912–7.
Cassagne C, Ranque S, Normand AC, et al. Mould routine identification in the clinical laboratory by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. PLoS One. 2011;6:e28425.
Ranque S, Normand AC, Cassagne C, et al. MALDI-TOF mass spectrometry identification of filamentous fungi in the clinical laboratory. Mycoses. 2014;57:135–40.
Santos C, Paterson RR, Venâncio A, Lima N. Filamentous fungal characterizations by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. J Appl Microbiol. 2010;108:375–85.
Alshawa K, Beretti JL, Lacroix C, et al. Successful identification of clinical dermatophyte and Neoscytalidium species by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol. 2012;50:2277–81.
Calderaro A, Motta F, Montecchini S, et al. Identification of dermatophyte species after implementation of the in-house MALDI-TOF MS database. Int J Mol Sci. 2014;15:16012–24.
De Respinis S, Tonolla M, Pranghofer S, et al. Identification of dermatophytes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Med Mycol. 2013;51:514–21.
De Respinis S, Monnin V, Girard V, et al. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry using the Vitek MS system for rapid and accurate identification of dermatophytes on solid cultures. J Clin Microbiol. 2014;52:4286–92.
Karabıçak N, Karatuna O, İlkit M, Akyar I. Evaluation of the Bruker matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) system for the identification of clinically important dermatophyte species. Mycopathologia. 2015;180:165–71.
L’Ollivier C, Cassagne C, Normand AC, et al. A MALDI-TOF MS procedure for clinical dermatophyte species identification in the routine laboratory. Med Mycol. 2013;51:713–20.
Packeu A, De Bel A, l’Ollivier C, et al. Fast and accurate identification of dermatophytes by matrix-assisted laser desorption ionization-time of flight mass spectrometry: validation in the clinical laboratory. J Clin Microbiol. 2014;52:3440–3.
Theel ES, Hall L, Mandrekar J, Wengenack NL. Dermatophyte identification using matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol. 2011;49:4067–71.
Carbonnelle E, Beretti JL, Cottyn S, et al. Rapid identification of staphylococci isolated in clinical microbiology laboratories by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol. 2007;45:2156–61.
Pennanec X, Dufour A, Haras D, Réhel K. A quick and easy method to identify bacteria by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Rapid Commun Mass Spectrom. 2010;24:384–92.
Chalupová J, Raus M, Sedlářová M, Sebela M. Identification of fungal microorganisms by MALDI-TOF mass spectrometry. Biotechnol Adv. 2014;32:230–41.
Hettick JM, Green BJ, Buskirk AD, et al. Discrimination of Penicillium isolates by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry fingerprinting. Rapid Commun Mass Spectrom. 2008;22:2555–60.
Welham KJ, Domin MA, Johnson K, Jones L, Ashton DS. Characterization of fungal spores by laser desorption/ionization time-of-flight mass spectrometry. Rapid Commun Mass Spectrom. 2000;14:307–10.
Tholey A, Heinzle E. Ionic (liquid) matrices for matrix-assisted laser desorption/ionization mass spectrometry-applications and perspectives. Anal Bioanal Chem. 2006;386:24–37.
Cassagne C, Normand AC, L’Ollivier C, Ranque S, Piarroux R. Performance of MALDI-TOF MS platforms for fungal identification. Mycoses. 2016 Apr. 8. doi: 10.1111/myc.12506. [Epub ahead of print] Review. PMID: 27061755.
Normand AC, Cassagne C, Ranque S, et al. Assessment of various parameters to improve MALDI-TOF MS reference spectra libraries constructed for the routine identification of filamentous fungi. BMC Microbiol. 2013;13:76.
Irinyi L, Serena C, Garcia-Hermoso D, et al. International Society of Human and Animal Mycology (ISHAM)-ITS reference DNA barcoding database—the quality controlled standard tool for routine identification of human and animal pathogenic fungi. Med Mycol. 2015;53:313–37.
Martiny D, Cremagnani P, Gaillard A, et al. Feasibility of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) networking in university hospitals in Brussels. Eur J Clin Microbiol Infect Dis. 2014;33:745–54.
Robert R, Pihet M. Conventional methods for the diagnosis of dermatophytosis. Mycopathologia. 2008;166:295–306.
Hay R. Literature review. Onychomycosis. J Eur Acad Dermatol Venereol. 2005;19(Suppl 1):1–7.
Hollemeyer K, Jager S, Altmeyer W, Heinzle E. Proteolytic peptide patterns as indicators for fungal infections and nonfungal affections of human nails measured by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Anal Biochem. 2005;338:326–31.
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We thank Sandra Moore for proofreading the manuscript.
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L’Ollivier, C., Ranque, S. MALDI-TOF-Based Dermatophyte Identification. Mycopathologia 182, 183–192 (2017). https://doi.org/10.1007/s11046-016-0080-x
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DOI: https://doi.org/10.1007/s11046-016-0080-x