Evaluation of a new extraction protocol for yeast identification by mass spectrometry

• Rapid and safe pretreatment procedure for MALDI-TOF yeast avoiding formic acid.
• Performance of glass bead new extraction method for the accurate identification of pathogenic Candida species.
• Creation and validation of yeast database library using clinical isolates.

In this paper, we evaluate a rapid and safe pretreatment procedure using glass beads for MALDI-TOF yeast identification in a routine clinical laboratory avoiding the use of formic acid. We created a new yeast database library using 1186 yeasts, including 11 references strains. The database was tested using 2131 clinical isolates allowing accurate species-level identification in 98.9% (2107/2131) of cases with a score over 1.9 and in 99% (2123/2131) of the strains at the genus level. The new protocol is a rapid, reliable and safe procedure for the accurate identification of pathogenic Candida strains and requires minimal handling.