Expression of collagen-binding protein and types 5 and 8 capsular polysaccharide in clinical isolates of Staphylococcus aureus

In vitro collagen binding of 216 Staphylococcus aureus isolates from patients with various diagnoses was studied. Polymerase chain reaction was used to examine these isolates regarding the existence of the corresponding cnagene. Distribution of capsular polysaccharide (CP) types was examined. Fifty-six (57%) of 99 S. aureus isolates from patients with endocarditis or bacteremic bone or joint infection were cna-positive compared with 65 (56%) of 117 isolates from bacteremic patients without signs of bone or joint infection (P =.99). There was a good correlation between in vitro collagen binding and presence of the cna gene. These data suggest that collagen binding is not a prerequisite for the development of endocarditis, osteomyelitis, or septic arthritis. There was no significant difference in the distribution of CP types among various patient groups, although there was a strong association between CP type 8 and the existence of the cna gene.