LOCALIZATION OF STAPHYLOCOCCUS-AUREUS IN INFECTED AIRWAYS OF PATIENTSWITH CYSTIC-FIBROSIS AND IN A CELL-CULTURE MODEL OF STAPHYLOCOCCUS-AUREUS ADHERENCE

Staphylococcus aureus causes chronic respiratory tract infections in p atients with cystic fibrosis (CF). Using immunofluorescence and scanni ng and transmission electron microscopy we located S. aureus in lung s pecimens of three infected CF patients, in a nasal polyp of one CF pat ient, and in a suspension cell culture system of primary nasal epithel ial cells in vitro. Very little of S. aureus was attached to the lung epithelium, whereas abundant S. aureus was detectable in the mucus of obstructed airways. Similarly, S. aureus adhered to components of secr eted mucus on primary nasal epithelial cells of CF patients and health y control subjects, grown as cell balls in vitro (bacteria/cell +/- SD : CF: 21.9 +/- 1.5; controls: 22.0 +/- 5.8). Mucus depletion of cell b alls prior to incubation with S. aureus resulted in a significantly re duced binding (bacteria/cell +/- SD: CF: 4.2 +/- 0.3; P < 0.001; contr ols: 5.0 +/- 1.3; P < 0.007). Binding of S. aureus to cell balls from CF patients or control subjects did not differ significantly. When cel l balls were treated with human neutrophil elastase, hypersecretion ca used removal of S. aureus from cell-associated mucus. The results sugg est that S, aureus adheres primarily to mucus components of the respir atory epithelium and that significant differences do not exist in bind ing of S. aureus to CF or non-CF cells.