Proteomic profiling of intact mycobacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
Hettick-JM; Kashon-ML; Simpson-JP; Siegel-PD; Mazurek-GH; Weissman-DN
Anal Chem 2004 Oct; 76(19):5769-5776
Current methods for the identification of mycobacteria in culture are time-consuming, requiring as long as 12 weeks for positive identification. One potential approach to rapid mycobacterial identification is to utilize proteomic profiling of cultures by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In this report, we have applied MALDI-TOF MS to proteomic profiling of cultured microorganisms representing six species of the genus Mycobacterium. We find that analysis of acetonitrile/trifluoroacetic acid cellular extracts produces data similar to that of the analysis of deposited whole cells, while minimizing human contact with the microorganisms and rendering them nonviable. A matrix composition of alpha-cyano-4-hydroxycinnamic acid with fructose yields highly reproducible MALDI-TOF spectra. Statistical analysis of MALDI-TOF MS data allows differentiation of each individual mycobacterial species on the basis of unique mass fingerprints. The methodology allows identification of a number of unique (potentially diagnostic) biomarkers as targets for protein identification by MS/MS experiments. In addition, we observe a number of signals common to all mycobacterial species studied by MALDI-TOF MS, which may be genus-specific biomarkers. The potentially genus-specific biomarkers occur at low mass (<2 kDa) and are likely to be lipids and cell wall components such as mycolic acids. This study demonstrates the potential for mass spectrometry-based identification/classification of mycobacteria.
Ionization; Mass-spectrometry; Microorganisms; Acetones; Statistical-analysis; Biomarkers; Bacteria; Diseases; Disaster-prevention; Infectious-diseases; Lasers
National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, 1095 Willowdale Road, Morgantown, WV 26505
Disease and Injury: Infectious Diseases