Mass Spectrometry and Tandem Mass Spectrometry for Protein Biomarker Discovery and Bacterial Speciation

After culture, MALDI-MS protein profiling, for species characterization, is widely used. DNA-based identification of bacterial species (with or without prior culture) often involves PCR and/or sequencing. 16S rRNA sequence cataloging is the gold standard but discrimination is often only at the genus level. This chapter discusses protein marker discovery and chemotaxonomy for threat agents using MS and MS/MS. Characterization of small acid soluble proteins (SASPs) of Bacillus anthracis and related species are used for illustrative purposes. The ultimate goal of our studies is universal applicability with species-level certainty in these identifications including biodetection without culture.