Collagen binding in clinical isolates of Staphylococcus aureus

Collagen binding was examined in 90 strains of Staphylococcus aureus derived from patient samples. Slightly under one-half (39 of 90) of the S. aureus strains bound collagen. Collagen binding in S. aureus did not correlate with either immunoglobulin G or fibronectin binding by these organisms. Chi-square analysis of isolates obtained from patients with complicated bacteremia (bacteremia associated with deep tissue infection) compared with isolates from patients with uncomplicated bacteremia (bacteremia without other infection) showed that the former strains were significantly more likely to have collagen-binding ability. Subcloning of primary isolates from patients with bacteremia showed that all clones from individual patients were either all positive for collagen binding or all negative, suggesting a common clonal origin for this characteristic. The ability to bind collagen could not be induced in strains lacking collagen affinity by repeated subculture in media supplemented with collagen.