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

Proteomic techniques relaying upon mass spectrometry (MALDI_TOF) applied to nontuberculous mycobacteria (NTM) identification, constitute a difficult goal. Cell wall structure features complicates the protein extraction procedure. A total of 106 isolates belonging to a variety of MNTs species isolated from clinical samples taken at the Complejo Asistencial Universitario de León for a two years period (2019-20) were identified following a simplified method (MALDI-TOF Biotyper Bruker®) developped in our laboratory. The resultant identification was compared to a parallel one ruled on the Centro de Referencia de Majadahonda. A total of 22different MNTs species were tested, obtaining an agreement of 92,45%. Only 8 minor discrepancies between species belonging to same taxonomic group of MNTs were detected. The score obtained in the 67.92% of the cases was higher than 1.8. A time-saving of 24min compared to the manufacturer's proceeding was achieved.