Identification of Mycobacterium Species by MALDI-TOF Mass Spectrometry
Matrix-assisted laser desorption ionization – time-of-flight (MALDI-TOF) mass spectrometry enables to identify microorganisms by comparison of the protein content with reference spectra in the database. The aim of this study was to evaluate the efficacy of phenotypic identification of mycobacteria by MALDI-TOF mass spectrometry in laboratory practice. Seventy five isolates of mycobacteria were identified by molecular and phenotypic method, and the results were compared by MALDI-TOF. For MALDI-TOF, material was processed according to the Bruker Daltonics protocol and Mycobacterial Library database version 2.0, with 313 reference mycobacteria spectra. All except one of the 72 isolates agreed with regard to the species and genus by both methods. Forty three isolates were identified as the M. tuberculosis complex by MALDI-TOF. Thirty one isolates of nontuberculous mycobacteria were consistently identified by both methods to the species level. We conclude that MALDI-TOF mass spectrometry is an accurate method of bacterial identification. Simplicity, speed, and economic availability of the method makes it suitable for mycobacteria identification in a routine laboratory.
KeywordsBacterial isolates Mass spectrometry Mycobacterium tuberculosis Phenotype bacterial identification Protein identification
Supported by project KEGA 032UK-4/2015 – Modern Education for Knowledge Society of the Ministry of Education, Slovak Republic.
Conflicts of Interest
The authors declare no conflicts of interest in relation to this article.
- Dixon P, Davies P, Hollingworth W, Stoddart M, MacGowan A (2015) A systematic review of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry compared to routine microbiological methods for the time taken to identify microbial organisms from positive blood cultures. Eur J Clin Microbiol Infect Dis 34:863–876CrossRefPubMedGoogle Scholar
- Griffith DE, Aksamit T, Brown-Elliot BA, Catanzaro A, Daley C, Gordin F, Holland SM, Horsburgh R, Huitt G, Iademarco MF, Iseman M, Olivier K, Ruoss S, von Reyn CF, Wallace RJ Jr, Winthrop K, ATS Mycobacterial Diseases Subcommittee; American Thoracic Society; Infectious Disease Society of America (2007) An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial disease. Am J Respir Crit Care Med 175:367–416CrossRefPubMedGoogle Scholar
- Pranada AB, Timke M, Witt E, Kostrzewa M (2015) Mycobacteria identification by MALDI Biotyper System: evolution of database content and evaluation criteria. 25th ECCMID, Copenhagen, Poster 1190; https://www.escmid.org/escmid_publications/escmid_elibrary/material/?mid=29197. Accessed 18 Oct 2016
- Quinlan P, Phelan E, Doyle M (2015) Matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry (MS) for the identification of mycobacteria from MBBacT ALERT 3D liquid cultures and Lowenstein-Jensen (LJ) solid cultures. J Clin Pathol 68:229–235CrossRefPubMedGoogle Scholar
- Tonolla M, Benagli C, Rossi V, Fragoso C, Petrini O (2010) MALDI-TOF MS: a new laboratory option for the diagnosis of clinical infections. Pipette 3:6–10Google Scholar