Binding of type‐I and type‐II collagens to Staphylococcus aureus strains isolated from patients with toxic shock syndrome compared to other staphylococcal infections

Toxic shock syndrome toxin‐1 (TSST‐1) producing strains of Staphylococcus aureus isolated from 18 patients with toxic shock syndrome (TSS) and from 56 patients with other diagnoses were compared for capacity to interact with various serum and connective tissue proteins. TSS associated isolates showed significantly stronger binding of Type‐I collagen (Cn‐I) and Cn‐II than non‐TSS strains, in a particle agglutination assay (PAA) as well as in 125 I labelled Cn uptake experiments. 125 I Cn‐IV binding, was similar between the two groups, whereas in PAA, a stronger interaction was observed for non‐TSS than TSS associated strains. The median binding of 125 I Cn to TSS‐associated strains were 52.2 (Cn‐I), 30.6 (Cn‐II) and 20.0 (Cn‐IV) compared to 20.0 (Cn‐I), 14.4 (Cn‐II) and 24.4 (Cn‐IV) values of non‐TSS strains. A saturation with 125 I Cn‐I and Cn‐II binding was established for TSS (30 min) and non‐TSS (15 min) strains. 125 I Cn‐IV binding reached a saturation in 10 min and 90 min with TSS and non‐TSS strains respectively. Finally, the binding profiles of TSS associated and non‐TSS strains to fibronectin, fibrinogen, laminin and IgG did not differ in both PAA and radioisotope assays. In scanning electron microscopy, cells of TSS associated strains bound to the reprecipitated native Cn‐I fibrils. In contrast, most cells of non‐TSS strains were localized to the distal end or were trapped between the Cn fibrils. The stronger interaction with Cn‐I and II in particular, shown by TSS associated strains, might enhance submucosal localization, thereby facilitating entry of toxins into the blood and establishment of TSS.