Direct Identification of Yeasts from Blood Cultures and Body Fluids Using MALDI-TOF MS with Concurrent Antifungal Susceptibility Testing

The rising incidence of invasive fungal infections has been accompanied by an increasing prevalence of antifungal resistance among fungal pathogens. Rapid identification of causative agents and their antifungal susceptibility profiles is critical for initiating timely, species-specific targeted therapy. In this context, we evaluated a MALDI-TOF MS-based method for the rapid identification of clinically relevant yeast species directly from blood cultures and body fluids, coupled with direct antifungal susceptibility testing (Direct-AFST). Our study evaluated over 700 yeast isolates, encompassing diverse Candida and non- Candida species, using MALDI-TOF MS. Additionally, antifungal susceptibility was assessed for 250 isolates, demonstrating excellent categorical agreement between Direct-AFST and conventional culture-based AFST (Culture-AFST). Our findings highlight the clinical utility of MALDI-TOF MS for accurate and rapid yeast identification directly from positive blood cultures, irrespective of microbial load or sample preparation method. Furthermore, the successful application of Direct-AFST underscores its potential for early detection of antifungal resistance, significantly reducing diagnostic turnaround times and improving patient management.