Comparison of the Filamentous Fungi Library v4.0 MALDI Biotyper Platform vs MSI-2 performance for identifying filamentous fungi from liquid cultures

Author: mycolabadmin
1/31/2025
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Summary

This study compared two advanced technologies for identifying dangerous fungi in clinical samples. The MALDI Biotyper FFLv4.0 system identified about 96% of fungi correctly when using liquid culture samples, outperforming the MSI-2 database which identified about 78.5%. Both systems had difficulty with certain difficult-to-distinguish species, especially within Aspergillus and Fusarium groups, but performed well with Mucorales fungi. The findings suggest that continuous updating of these fungal identification libraries is essential for improving patient care.

Background

Filamentous fungi are emerging pathogens causing invasive fungal infections with significant morbidity and mortality in immunocompromised patients. Rapid and reliable identification is crucial for timely diagnosis and antifungal therapy. MALDI-TOF mass spectrometry has revolutionized clinical microbiology for identifying bacteria and yeasts, but its application to filamentous fungi has been limited by reduced diversity in commercial libraries.

Objective

This study compared the performance of the Filamentous Fungi Library v4.0 (FFLv4.0) MALDI Biotyper platform versus the MSI-2 database for identifying filamentous fungi from clinical isolates. The comparison used molecular sequencing as the reference standard to evaluate identification accuracy at genus, section, species complex, and species levels.

Results

FFLv4.0 achieved 96% correct identification at genus/section/species complex level compared to 78.5% for MSI-2, and 69% species-level accuracy versus 53% for MSI-2. Non-identification rates were 4% for FFLv4.0 and 21.5% for MSI-2. FFLv4.0 had higher misidentification rates at the species level (19.5% vs 6.5%), particularly for Aspergillus section Nigri and Fusarium species.

Conclusion

The FFLv4.0 MALDI Biotyper outperformed MSI-2 when analyzing spectra from liquid culture media. Mucorales, Fusarium, and Aspergillus species were reliably identified at genus, species complex, and section levels respectively. Both commercial and public libraries require continuous updating and curation to improve clinical mycology diagnostics.

Published in:Journal of Clinical Microbiology,
Study Type:Comparative Clinical Laboratory Study,
Source: 10.1128/jcm.01371-24, PMID: 39887202