A rapid proteomic system (MALDI-TOF) for nontuberculous-mycobacteria identification

Area of Science:

• Clinical microbiology
• Proteomics
• Mass spectrometry

Background:

• Nontuberculous mycobacteria (NTM) identification is challenging due to complex cell wall structures.
• Standard proteomic techniques using MALDI-TOF require intricate protein extraction procedures.

Purpose of the Study:

• To develop and evaluate a simplified MALDI-TOF mass spectrometry method for NTM identification.
• To assess the accuracy and efficiency of the simplified method compared to a reference standard.

Main Methods:

• A simplified MALDI-TOF Biotyper Bruker® method was developed in-house.
• 106 clinical NTM isolates from León, Spain (2019-20) were analyzed.
• Results were compared against identification performed at the Reference Center in Majadahonda.

Main Results:

• The simplified method identified 22 different NTM species with 91.5% agreement compared to the reference method.
• Minor discrepancies (9 cases) occurred only between species within the same taxonomic group.
• High identification scores (>1.8) were achieved in 67.92% of cases.
• A time saving of 24 minutes per sample was realized compared to the manufacturer's protocol.

Conclusions:

• The simplified MALDI-TOF method offers a rapid and accurate approach for NTM identification.
• This technique streamlines laboratory workflows and reduces diagnostic turnaround times.
• The method demonstrates high concordance with established identification standards, facilitating clinical application.