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

Abstract

A total of 89 Staphylococcus aureus strains were tested for |125 I|-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 a higher degree of interaction than clinical isolates (35 strains). Strains belonging to the 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 (sV/u). 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 [125 I]-Iabelled serum and connective tissue protein binding. Mucin concentrations of 100. 150, 175 and 250 µg/ml when incubated with 109 cells, caused 50% displacement of [ 125 I]-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.