An isolated extracellular matrix-binding protein, designated as SdrD and its corresponding amino acid and nucleic acid sequences and motifs are described. The proteins, peptides, fragments thereof or antigenic portions thereof are useful for the prevention, inhibition, treatment and diagnosis of S. aureus infection and as scientific research tools. Further, antibodies or antibody fragments to the proteins, peptides, fragments thereof or antigenic portions thereof are also useful for the prevention, inhibition, treatment and diagnosis of S. aureus infection. In particular, the proteins or antibodies thereof may be administered to wounds or used to coat biomaterials to act as blocking agents to prevent or inhibit the binding of S. aureus to wounds or biomaterials.