Virulence factors produced by Staphylococcus  aureus biofilms have a moonlighting function contributing to biofilm integrity.

Virulence factors produced by Staphylococcus aureus biofilms have a moonlighting function contributing to biofilm integrity. Mol Cell Proteomics. 2019 Mar 08;: Authors: Graf AC, Leonard A, Schäuble M, Rieckmann LM, Hoyer J, Maaß S, Lalk M, Becher D, Pané-Farré J, Riedel K Abstract Staphylococcus aureus is the causative agent of various biofilm-associated infections in humans causing major healthcare problems worldwide. This type of infection is inherently difficult to treat due to a reduced metabolic activity of biofilm-embedded cells and the protective nature of a surrounding extracellular matrix (ECM). However, little is known about S. aureus biofilm physiology and in particular the proteinaceous composition of the ECM. Thus, we cultivated S. aureus biofilms in a flow system and comprehensively profiled intracellular and extracellular (ECM and flow-through (FT)) biofilm proteomes, as well as the extracellular metabolome in comparison to planktonic cultures. Our analyses revealed the expression of many pathogenicity factors within S. aureus biofilms as indicated by a high abundance of capsule biosynthesis proteins along with various secreted virulence factors, including hemolysins, leukotoxins, and lipases as a part of the ECM. The activity of ECM virulence factors was confirmed in a hemolysis assay and a Galleria mellonella pathogenicity model. In addition, we uncovered a so far unacknowledged moonlighting function of sec...
Source: Molecular and Cellular Proteomics : MCP - Category: Molecular Biology Authors: Tags: Mol Cell Proteomics Source Type: research