Evaluation of the Vitek-MS™ system in the identification of Candida isolates from bloodstream infections.

BACKGROUND: Matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF-MS) represents a revolution in the identification of microorganisms of clinical interest. Many studies have confirmed the accuracy and fastness of this tool with routine strains.

AIMS: To identify clinical isolates of Candida from patients diagnosed with candidemia.

METHODS: Vitek-MS™ system was used with a collection of 298 blood isolates of the genus Candida represented by 9 different species. Sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA cluster was used as the reference method.

RESULTS: The results of Vitek-MS™ were concordant with those obtained with the reference method for 279 (93.62%) isolates (Kappa coefficient (κ)=0.91). Vitek-MS™ misidentified 10 (3.36%) isolates and did not identify 9 (3.02%) isolates.

CONCLUSIONS: This study determines the potential of Vitek-MS™ in yeast identification, being a reliable and fast alternative in the clinical laboratory, with an acceptable sensitivity of 82% (IC 95%: 70-90.6%), in comparison with a 100% (IC 95%: 92.9-100%) sensitivity of the conventional methods.