Medically important Candida spp. identification: an era beyond traditional methods

Authors: EBRU EVREN, JULİDE SEDEF GÖÇMEN, ELVAN HORTAÇ İŞTAR, ŞÜKRAN YAVUZDEMİR, FAZIL ALPER TEKELİ, YASEMİN YAVUZ, ZEYNEP CEREN KARAHAN

Abstract: Background/aim: Candida infections are gaining more attention for the last few decades so diagnostic tools are very important for early diagnosis. Conventional identification of yeasts is time-consuming, molecular methods are more complicated and relatively expensive gold-standard methods. Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) was put into the market due to its speed and high accuracy. The aim of this study was to evaluate the performance of corn meal tween-80 agar (CMTA), CHROMagar Candida medium, and MALDI-TOF MS and to compare the obtained results with DNA sequencing. Materials and methods: The CHROMagar Candida medium, CMTA, and MALDI-TOF MS Biotyper System were used to test 416 isolates. The isolates with discrepant results by at least one of the three methods were subjected to sequence analysis. Results: The identification results of the 351 (%84.4) were compatible with all three methods. When compared to the sequencing results, the most accurate results were obtained by the MALDI-TOF MS, especially for rare Candida species. Conclusion: MALDI-TOF MS is found to be the most accurate identification tool for clinically important Candida strains. CMTA alone should not be used for the final identification of Candida species and the chromogenic medium should always be considered presumptive.

Keywords: Candida identification, MALDI-TOF MS, CHROMagar Candida, corn meal tween-80 agar, sequencing

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