Influence of mucin on serum and connective tissue protein binding to Staphylococcus aureus isolated from nasal carriage and clinical sources.

A total of 89 Staphylococcus aureus strains were tested for [125I]-labelled fibronectin (Fn), type I (Cn-I), type II (Cn-II), type IV (Cn-IV) collagens and laminin (Lm) binding, and nasal carriage isolates (54 strains) demonstrated higher degree of interaction than clinical isolates (35 strains). Strains belonging to nasal carriage group, after preincubation with mucin demonstrated a significant decline in binding to Fn (39.4%), Cn-I (44.7%), Cn-IV (42.0%) and Lm (43.5%) compared with inhibition of binding of clinical isolates to Fn (13.3%), Cn-I (8.0%), Cn-IV (9.8%) and Lm (11.2%). S. aureus strain Nig-6 demonstrated a mucin concentration (in the range 0.01 to 100 mg/ml) dependent decrease of [125I]-labelled serum and connective tissue protein binding. Mucin concentrations of 100, 150, 175 and 250 micrograms/ml when incubated with 10(9) cells, caused 50% displacement of [125I]-labelled Lm, Cn-I, Cn-IV and Fn uptake respectively. Mucin interaction with bacterial cells seems probably important in the pathomechanism of staphylococcal adhesion and colonization.