The Role of Nanoscale Distribution of Fibronectin in the Adhesion of <i>Staphylococcus aureus</i> Studied by Protein Patterning and DNA-PAINT.

Abstract

<i>Staphylococcus aureus</i> is a widespread and highly virulent pathogen that can cause superficial and invasive infections. Interactions between <i>S. aureus</i> surface receptors and the extracellular matrix protein fibronectin mediate the bacterial invasion of host cells and is implicated in the colonization of medical implant surfaces. In this study, we investigate the role of distribution of both fibronectin and cellular receptors on the adhesion of <i>S. aureus</i> to interfaces as a model for primary adhesion at tissue interfaces or biomaterials. We present fibronectin in patches of systematically varied size (100-1000 nm) in a background of protein and bacteria rejecting chemistry based on PLL-<i>g</i>-PEG and studied <i>S. aureus</i> adhesion under flow. We developed a single molecule imaging assay for localizing fibronectin binding receptors on the surface of <i>S. aureus</i> via the super-resolution DNA points accumulation for imaging in nanoscale topography (DNA-PAINT) technique. Our results indicate that <i>S. aureus</i> adhesion to fibronectin biointerfaces is regulated by the size of available ligand patterns, with an adhesion threshold of 300 nm and larger. DNA-PAINT was used to visualize fibronectin binding receptor organization <i>in situ</i> at ∼7 nm localization precision and with a surface density of 38-46 μm^-2, revealing that the engagement of two or more receptors is required for strong <i>S. aureus</i> adhesion to fibronectin biointerfaces.