The 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.

Biomedical Center Faculty of Medicine in Plzen Plzen Czech Republic

Department of Clinical and Molecular Microbiology University Hospital Centre Zagreb Zagreb Croatia

Department of Clinical Microbiology and Infectious Diseases Hospital General Universitario Gregorio Marañón Madrid Spain

Department of Medical Microbiology MVZ Dr Eberhard and Partner Dortmund Dortmund Germany

Dept of Biological Sciences Munster Technological University Cork Ireland

Division of Human Bacterial diseases Sciensano Brussels Belgium

Division of Hygiene and Medical Microbiology Medical University of Innsbruck Innsbruck Austria

Health Services Laboratories London UK

Institut de Microbiologie Université de Lausanne Lausanne Switzerland

Laboratorie de Bactériologie Plateforme de Biologie Hôpital Cavale Blanche Brest France

Laboratorio de Microbiologia Hospital de la Santa Creu i Sant Pau Barcelona Spain

Laboratorio de Microbiología Hospital Regional de Málaga Málaga Spain

Oslo University Hospital Oslo Norway

Radboud University Medical Centre Nijmegen The Netherlands

Servei de Microbiologia CDB Hospital Clínic de Barcelona ISGlobal Departament Fonaments Clínics Facultat de Medicina i Ciències de la Salut Universitat de Barcelona Barcelona Spain

Servei de Microbiologia Hospital Universitari de Bellvitge IDIBELL Departament de Patologia i Terapèutica Experimental Facultat de Medicina i Ciències de la Salut Universitat de Barcelona Hospitalet de Llobregat Spain

Servicio de Microbiología Hospital Universitario A Coruña Coruña Spain

Servicio de Microbiología Hospital Universitario Central de Asturias Oviedo Spain

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Porvaznik I, Solovic I, Mokry J. Non-tuberculous mycobacteria: Classification, diagnostics, and therapy. Adv. Exp. Med. Biol. 2017;944:19–25. doi: 10.1007/5584_2016_45. PubMed DOI

van Ingen J. Microbiological diagnosis of nontuberculous mycobacterial pulmonary disease. Clin. Chest Med. 2015;36:43–54. doi: 10.1016/j.ccm.2014.11.005. PubMed DOI

Griffith DE, et al. An official ATS/IDSA statement: Diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. Am. J. Respir. Crit. Care Med. 2007;175:367–416. doi: 10.1164/rccm.200604-571ST. PubMed DOI

Haworth CS, et al. British Thoracic Society guidelines for the management of non-tuberculous mycobacterial pulmonary disease (NTM-PD) Thorax. 2017;72:ii1–ii64. doi: 10.1136/thoraxjnl-2017-210927. PubMed DOI

Rodriguez-Sanchez B, et al. Evaluation of MALDI biotyper mycobacteria library v3.0 for identification of nontuberculous mycobacteria. J. Clin. Microbiol. 2016;54:1144–1147. doi: 10.1128/JCM.02760-15. PubMed DOI PMC

Rodriguez-Temporal D, Perez-Risco D, Struzka EA, Mas M, Alcaide F. Impact of updating the MALDI-TOF MS database on the identification of nontuberculous mycobacteria. J. Mass Spectrom. 2017;52:597–602. doi: 10.1002/jms.3944. PubMed DOI

Tudo G, et al. Implementation of MALDI-TOF MS technology for the identification of clinical isolates of Mycobacterium spp. in mycobacterial diagnosis. Eur. J. Clin. Microbiol. Infect. Dis. 2015;34:1527–1532. doi: 10.1007/s10096-015-2381-2. PubMed DOI

Lotz A, et al. Rapid identification of mycobacterial whole cells in solid and liquid culture media by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J. Clin. Microbiol. 2010;48:4481–4486. doi: 10.1128/JCM.01397. PubMed DOI PMC

Saleeb PG, Drake SK, Murray PR, Zelazny AM. Identification of mycobacteria in solid-culture media by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J. Clin. Microbiol. 2011;49:1790–1794. doi: 10.1128/JCM.02135. PubMed DOI PMC

Rodriguez-Temporal D, Perez-Risco D, Struzka EA, Mas M, Alcaide F. Evaluation of two protein extraction protocols based on freezing and mechanical disruption for identifying nontuberculous mycobacteria by matrix-assisted laser desorption ionization-time of flight mass spectrometry from liquid and solid cultures. J. Clin. Microbiol. 2018 doi: 10.1128/JCM.01548-17. PubMed DOI PMC

Alcaide F, et al. How to: identify non-tuberculous Mycobacterium species using MALDI-TOF mass spectrometry. Clin. Microbiol. Infect. 2018;24:599–603. doi: 10.1016/j.cmi.2017.11.012. PubMed DOI

Marekovic I, et al. Evaluation of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in identification of nontuberculous mycobacteria. Chemotherapy. 2016;61:167–170. doi: 10.1159/000442517. PubMed DOI

Ceyssens PJ, et al. Matrix-assisted laser desorption ionization-time of flight mass spectrometry for combined species identification and drug sensitivity testing in mycobacteria. J. Clin. Microbiol. 2017;55:624–634. doi: 10.1128/JCM.02089-16. PubMed DOI PMC

Walker J, Fox A, Edward-Jones V, Gordon D. Intact cell mass spectrometry (ICMS) used to type methicillin-resistant Staphylococcus aureus: Media effects and inter-laboratory reproducibility. J. Microbiol. Methods. 2002;48:117–126. doi: 10.1016/s0167-7012(01)00316-5. PubMed DOI

Wunschel SC, et al. Bacterial analysis by MALDI-TOF mass spectrometry: An inter-laboratory comparison. J. Am. Soc. Mass Spectrom. 2005;16:456–462. doi: 10.1016/j.jasms.2004.12.004. PubMed DOI

Mellmann A, et al. High interlaboratory reproducibility of matrix-assisted laser desorption ionization-time of flight mass spectrometry-based species identification of nonfermenting bacteria. J. Clin. Microbiol. 2009;47:3732–3734. doi: 10.1128/JCM.00921-09. PubMed DOI PMC

Veloo ACM, et al. A multi-center ring trial for the identification of anaerobic bacteria using MALDI-TOF MS. Anaerobe. 2017;48:94–97. doi: 10.1016/j.anaerobe.2017.07.004. PubMed DOI

Lau AF, et al. Multicenter study demonstrates standardization requirements for mold identification by MALDI-TOF MS. Front. Microbiol. 2019;10:2098. doi: 10.3389/fmicb.2019.02098. PubMed DOI PMC

Veloo AC, Elgersma PE, Friedrich AW, Nagy E, van Winkelhoff AJ. The influence of incubation time, sample preparation and exposure to oxygen on the quality of the MALDI-TOF MS spectrum of anaerobic bacteria. Clin. Microbiol. Infect. 2014;20:O1091–1097. doi: 10.1111/1469-0691.12644. PubMed DOI

Rodriguez-Temporal D, Rodriguez-Sanchez B, Alcaide F. Evaluation of MALDI biotyper interpretation criteria for accurate identification of nontuberculous mycobacteria. J. Clin. Microbiol. 2020 doi: 10.1128/JCM.01103-20. PubMed DOI PMC

Wilson RW, et al. Mycobacterium immunogenum sp. nov., a novel species related to Mycobacterium abscessus and associated with clinical disease, pseudo-outbreaks and contaminated metalworking fluids: an international cooperative study on mycobacterial taxonomy. Int. J. Syst. Evol. Microbiol. 2001;51:1751–1764. doi: 10.1099/00207713-51-5-1751. PubMed DOI

Whipps CM, Butler WR, Pourahmad F, Watral VG, Kent ML. Molecular systematics support the revival of Mycobacterium salmoniphilum (ex Ross 1960) sp. nov., nom. rev., a species closely related to Mycobacterium chelonae. Int. J. Syst. Evol. Microbiol. 2007;57:2525–2531. doi: 10.1099/ijs.0.64841-0. PubMed DOI

O'Connor JA, et al. Improved matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based identification of Mycobacterium spp. by use of a novel two-step cell disruption preparatory technique. J. Clin. Microbiol. 2016;54:495–496. doi: 10.1128/JCM.02998-15. PubMed DOI PMC