Proteomics in studies of Staphylococcus aureus virulence

Staphylococcus aureus is a widespread, opportunistic pathogen that causes community and hospital acquired infections. Its high pathogenicity is driven by multifactorial and complex mechanisms determined by the ability of the bacterium to express a wide variety of virulence factors. The proteome secreted into extracellular milieu is a rich reservoir of such factors which include mainly nonenzymatic toxins and enzymes. Simultaneously, membrane proteins, membrane-cell wall interface proteins and cell wall-associated proteins also strongly influence staphylococcal virulence. Proteomics shows a great potential in exploring the role of the extracellular proteome in cell physiology, including the pathogenic potential of particular strains of staphylococci. In turn, understanding the bacterial physiology including the interconnections of particular factors within the extracellular proteomes is a key to the development of the ever needed, novel antibacterial strategies. Here, we briefly overview the latest applications of gel-based and gel-free proteomic techniques in the identification of the virulence factors within S. aureus secretome and surfacome. Such studies are of utmost importance in understanding the host-pathogen interactions, analysis of the role of staphylococcal regulatory systems and also the detection of posttranslational modifications emerging as important modifiers of the infection process.