Binding of collagen, fibronectin, lactoferrin, laminin, vitronectin and heparan sulphate to Staphylococcus aureus strain V8 at various growth phases and under nutrient stress conditions.

ABSTRACT

We have examined how Staphylococcus aureus strain V8 cells interact with 125I-labelled extracellular matrix (ECM) and serum proteins (collagen type I and IV), fibronectin, lactoferrin, laminin, vitronectin, and heparan sulphate at various phases of the growth cycle. Maximal binding of these glycoproteins and heparan sulphate to the bacteria occurred after 17 to 20 h in the late stationary phase except for fibronectin-binding, which was maximal after 12 to 14 h. Binding of the glycoproteins and heparan sulphate to S. aureus V8 under nutrient stress conditions exhibited complex patterns based on different starving conditions and various binding ligands. In general, bacteria starved in distilled water and 0.02 M potassium phosphate buffer (pH 7.2) at room temperature showed high susceptibility to all binding ligands within the first 18 h, followed by entering a lower binding period (except for collagen-binding which still remained high). The binding was not correlated to cell surface charge or hydrophobicity of the bacteria. Furthermore, extracellular and cell-associated proteolytic activity of starved cells against ECM and serum proteins was found to be greater than for non-starved cells. Thus, S. aureus could sustain its ability to bind various connective tissue and cell surface components during a long period of time even in the absence of energy-yielding substrates.