Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Identification of Mycobacteria in Routine Clinical Practice
Open Access
- 13 September 2011
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 6 (9), e24720
- https://doi.org/10.1371/journal.pone.0024720
Abstract
Non-tuberculous mycobacteria recovered from respiratory tract specimens are emerging confounder organisms for the laboratory diagnosis of tuberculosis worldwide. There is an urgent need for new techniques to rapidly identify mycobacteria isolated in clinical practice. Matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS) has previously been proven to effectively identify mycobacteria grown in high-concentration inocula from collections. However, a thorough evaluation of its use in routine laboratory practice has not been performed. We set up an original protocol for the MALDI-TOF MS identification of heat-inactivated mycobacteria after dissociation in Tween-20, mechanical breaking of the cell wall and protein extraction with formic acid and acetonitrile. By applying this protocol to as few as 105 colony-forming units of reference isolates of Mycobacterium tuberculosis, Mycobacterium avium, and 20 other Mycobacterium species, we obtained species-specific mass spectra for the creation of a local database. Using this database, our protocol enabled the identification by MALDI-TOF MS of 87 M. tuberculosis, 25 M. avium and 12 non-tuberculosis clinical isolates with identification scores ≥2 within 2.5 hours. Our data indicate that MALDI-TOF MS can be used as a first-line method for the routine identification of heat-inactivated mycobacteria. MALDI-TOF MS is an attractive method for implementation in clinical microbiology laboratories in both developed and developing countries.Keywords
This publication has 42 references indexed in Scilit:
- Probable Zoonotic Leprosy in the Southern United StatesThe New England Journal of Medicine, 2011
- Rapid Identification of Mycobacterial Whole Cells in Solid and Liquid Culture Media by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass SpectrometryJournal of Clinical Microbiology, 2010
- Rapid Molecular Detection of Tuberculosis and Rifampin ResistanceThe New England Journal of Medicine, 2010
- Real-Time Identification of Bacteria and Candida Species in Positive Blood Culture Broths by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass SpectrometryJournal of Clinical Microbiology, 2010
- Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Direct Bacterial Identification from Positive Blood Culture PelletsJournal of Clinical Microbiology, 2010
- Rapid Identification of Bacteria in Positive Blood Culture Broths by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass SpectrometryJournal of Clinical Microbiology, 2010
- Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Nonfermenting Gram-Negative Bacilli Isolated from Cystic Fibrosis PatientsJournal of Clinical Microbiology, 2008
- Microscopic-Observation Drug-Susceptibility Assay for the Diagnosis of TBThe New England Journal of Medicine, 2006
- Identification of Mycobacteria by Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass SpectrometryJournal of Clinical Microbiology, 2006
- Inactivation of Cultured Mycobacterium tuberculosis Organisms Prior to DNA ExtractionJournal of Clinical Microbiology, 2006