The effect of subinhibitory concentrations of antibiotics on adherence of Pseudomonas aeruginosa to cystic fibrosis (CF) and non-CF-affected trachealepithelial cells

Objectives: this project investigated the proposition that Pseudomonas aeru ginosa binds preferentially to cystic fibrosis (CF) respiratory cells, In a ddition, disadherence of P. aeruginosa by subinhibitory concentrations of a ntibiotics was examined as a possible explanation for clinical improvement seen in chronically colonized patients when treated with anti-pseudomonal a gents, Methods: we used a distinctive HPV-transformed respiratory cell line to com pare adherence of two strains of P. aeruginosa to CF and non-CF respiratory cells, The effect of subinhibitory concentrations of antipseudomonal antib iotics on adherence of P, aeruginosa to cell monolayers was measured. Results: piliated P. aeruginosa bound significantly better to CF than non-C F-affected cells (P=0.003). Adherence was significantly reduced when organi sms were preincubated in subinhibitory concentrations of antibiotics overni ght (P<0.001). Conclusions: these results support the presence of an altered receptor pres ent on CF-affected cells that binds piliated strains of P. aeruginosa. Bact erial disadherence due to subinhibitory concentrations of antibiotics may p artially explain why clinical improvement is observed in CF patients with a cute respiratory exacerbations.