Comparative Evaluation of MALDI-TOF MS and ITS Barcoding for the Identification of Clinical and Environmental Yeast Isolates

다국어 초록 (Multilingual Abstract)

Background: ITS barcoding is the "gold standard" method for fungal identification. However, it is associated with high costs, requires specialized expertise, and entails lengthy turnaround times. MALDI-TOF MS represents a more rapid and lower-cost alternative, but it is generally less sensitive and less specific than ITS barcoding.
Objective: This study aimed to investigate and assess MALDI-TOF MS and ITS barcoding for identifying yeast strains isolated from patients and domestic environments.
Methods: A total of 115 yeast strains, including 89 pathogenic and 26 environmental, were identified using MALDI-TOF MS and ITS barcoding with phylogenetic analyses. The identification results from the two methods were compared and assessed.
Results: ITS barcoding identified 115 strains, including ascomycetous yeasts (5 Candida species and 9 non-Candida species) and basidiomycetous yeasts (5 species and 1 species complex). In contrast, MALDI-TOF MS identified 74.78% (86/115) of the isolates, with an accuracy of 96.51% (83/86). The MS showed substantial agreement with ITS barcoding (κ = 0.65, p < 0.001) when all isolates were included, and this agreement strengthened (κ = 0.76, p < 0.001) when the analysis was restricted to species represented in the MS database. Furthermore, almost perfect agreement was observed (κ = 0.81, p < 0.001) for common pathogenic Candida species, achieving 100% identification rate and accuracy for C. albicans and C. tropicalis.
Conclusion: ITS barcoding remains the gold standard method for yeast identification. MALDI-TOF MS is a viable option for routine clinical use, but it requires database expansion and technical improvements for uncommon species or species complexes