Comparison of MALDI-TOF/MS and LC-QTOF/MS methods for the identification of enteric bacteria

Two complementary mass spectrometric techniques were evaluated for their applicability as methods for foodborne pathogen characterization, biomarker candidate discovery and identification. Ten clinical isolates of closely related organisms, Escherichia coli, Shigella sonnei and Shigella flexneri, were chosen for this study. Whole cell lysates were analyzed using both matrix assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF/MS) and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). Evaluation of isolate mass spectra revealed unique protein profile patterns and potential biomarkers capable of species and sub-species identification. Strengths of each MS method, in addition to their advantages over traditional methods, are highlighted and a brief discussion of their potential as standard tools in the laboratory is presented.

Graphical abstractA comparison of MALDI-TOF/MS and LC-QTOF/MS for the analysis of intact proteins.Figure optionsDownload full-size imageDownload high-quality image (155 K)Download as PowerPoint slide