Background and Purpose: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is widely used to discriminate among pathogenic
microorganisms in clinical
laboratories. The aim of this study was to assess the utility of MALDI-TOF MS in the routine identification of clinical dermatophyte isolates obtained from various geographical regions of Iran.
Materials and Methods: A total of 94 isolates, including Trichophyton interdigitale (n=44), T. rubrum (n=40), T. tonsurans (n=4), Microsporum canis (n=4), and Epidermophyton floccosum (n=1), were analyzed in this study. The identity of each
isolate was determined by polymerase chani reaction mplification and sequencing of the internal transcribed spacer (ITS) region of nuclear-encoded ribosomal DNA and also MALDI-TOF MS. The obtained data by molecular approach were compared with
Results: The MALDI-TOF MS led to the identification of 44 (47%) isolates at the species level by generating the spectral score values of ≥ 2.0. However, there was not sufficient agreement between the results of the molecular-based ITS identification methods and MALDI-TOF MS in the species identification of 16 (17%) isolates. The Bruker Daltonics database was also not able to identify protein spectra related to 12 isolates (13%), including
T. interdigitale (n=5), T. rubrum (n=4), M. canis (n=2), and T. tonsurans (n=1). Conclusion: According to the results, the utility of MALDI-TOF MS as a routine diagnostic tool for the accurate and reliable identification of dermatophytes can be justified whenever the protein spectra of a large set of worldwide clinical isolates are
included in the commercial libraries. In addition, MALDI-TOF MS can be alternatively used to construct an in-house reference database.
Mohammad Taghi Hedayati ,Saham Ansari ,Bahram Ahmadi ,Mojtaba Taghizadeh Armaki ,Tahereh Shokohi ,Mahdi Abastabar ,Halil Er ,Dilara Ogunc ,Betil Özhak ,Macit Ilkit ,Seyedmojtaba Seyedmousavi ,
Identification of clinical dermatophyte isolates obtained from Iran by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry,
22-26 . 10.18502/cmm.5.2.1157 Views : 0