Rodriguez-Temporal, DavidAlcaide, FernandoMareković, IvanaO'Connor, James AnthonyGorton, Rebeccavan Ingen, JakkoVan den Bossche, AnHéry-Arnaud, GenevieveBeauruelle, ClémenceOrth-Höller, DorotheaPalacios-Gutiérrez, Juan-JoséTudó, GriseldaBou, GermánCeyssens, Pieter-JanGarrigó, MontserratGonzález-Martin, JuliàGreub, GilbertHrabak, JaroslavIngebretsen, AndréMediavilla-Gradolph, Maria ConcepciónOviaño, MarinaPalop, BegoñaPranada, Arthur BQuiroga, LidiaRuiz-Serrano, Maria JesúsRodríguez-Sánchez, Belén2023-05-032023-05-032022-01-24http://hdl.handle.net/10668/19582The ability of MALDI-TOF for the identification of nontuberculous mycobacteria (NTM) has improved recently thanks to updated databases and optimized protein extraction procedures. Few multicentre studies on the reproducibility of MALDI-TOF have been performed so far, none on mycobacteria. The aim of this study was to evaluate the reproducibility of MALDI-TOF for the identification of NTM in 15 laboratories in 9 European countries. A total of 98 NTM clinical isolates were grown on Löwenstein-Jensen. Biomass was collected in tubes with water and ethanol, anonymized and sent out to the 15 participating laboratories. Isolates were identified using MALDI Biotyper (Bruker Daltonics). Up to 1330 MALDI-TOF identifications were collected in the study. A score ≥ 1.6 was obtained for 100% of isolates in 5 laboratories (68.2-98.6% in the other). Species-level identification provided by MALDI-TOF was 100% correct in 8 centres and 100% correct to complex-level in 12 laboratories. In most cases, the misidentifications obtained were associated with closely related species. The variability observed for a few isolates could be due to variations in the protein extraction procedure or to MALDI-TOF system status in each centre. In conclusion, MALDI-TOF showed to be a highly reproducible method and suitable for its implementation for NTM identification.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/HumansNontuberculous MycobacteriaReproducibility of ResultsSpecies SpecificitySpectrometry, Mass, Matrix-Assisted Laser Desorption-Ionizationresearch article35075208open access10.1038/s41598-022-05315-72045-2322PMC8786948https://www.nature.com/articles/s41598-022-05315-7.pdfhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC8786948/pdf