1. Fast identification of dermatophytes by MALDI-TOF/MS using direct transfer of fungal cells on ground steel target plates
- Author
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Lionel Fontao, Renaud Piarroux, Anne-Cécile Normand, Keith Cássia da Cunha, Philipp P. Bosshard, Margarete Teresa Gottardo de Almeida, Jacques Schrenzel, Arnaud Riat, University of Zurich, and Fontao, Lionel
- Subjects
Microbiological Techniques ,0301 basic medicine ,Dermatophytes ,Microbiological Techniques/methods ,Specimen Handling/methods ,030106 microbiology ,610 Medicine & health ,Dermatology ,Direct transfer ,Biology ,medicine.disease_cause ,Mass spectrometry ,Specimen Handling ,2708 Dermatology ,03 medical and health sciences ,Mass spectroscopy ,Arthrodermataceae/chemistry/classification/isolation & purification ,Matrix-Assisted Laser Desorption-Ionization/methods ,medicine ,Dermatomycoses ,Humans ,MALDI ,ddc:616 ,Chromatography ,Spectrometry ,Arthrodermataceae ,TOF ,Ms analysis ,10177 Dermatology Clinic ,2725 Infectious Diseases ,General Medicine ,Mass ,Matrix-assisted laser desorption/ionization ,030104 developmental biology ,Infectious Diseases ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Dermatophyte ,Dermatomycoses/diagnosis/microbiology ,Identification (biology) - Abstract
Dermatophytes cause human infections limited to keratinised tissues. We showed that the direct transfer method allows reliable identification of non-dermatophytes mould and yeast by MALDI-TOF/MS. We aimed at assessing whether the direct transfer method can be used for dermatophytes and whether an own mass spectra library would be superior to the Bruker library. We used the Bruker Biotyper to build a dermatophyte mass spectra library and assessed its performance by 1/testing a panel of mass spectrum produced with strains genotypically identified and, 2/comparing MALDI-TOF/MS identification to morphology-based methods. Identification of dermatophytes using the Bruker library is poor. Our library provided 97% concordance between ITS sequencing and MALDI-TOF/MS analysis with a panel of 1104 spectra corresponding to 276 strains. Direct transfer method using unpolished target plates allowed proper identification of 85% of dermatophytes clinical isolates most of which were common dermatophytes. A homemade dermatophyte MSP library is a prerequisite for accurate identification of species absent in the Bruker library but it also improves identification of species already listed in the database. The direct deposit method can be used to identify the most commonly found dermatophytes such as T. rubrum and T. interdigitale/mentagrophytes by MALDI-TOF/MS.
- Published
- 2018