The effect of subinhibitory concentrations of antibiotics on adherence of Pseudomonas aeruginosa to cystic fibrosis (CF) and non-CF-affected tracheal epithelial cells.
OBJECTIVE
this project investigated the proposition that Pseudomonas aeruginosa binds preferentially to cystic fibrosis (CF) respiratory cells. In addition, disadherence of P. aeruginosa by subinhibitory concentrations of antibiotics was examined as a possible explanation for clinical improvement seen in chronically colonized patients when treated with anti-pseudomonal agents.


METHODS
we used a distinctive HPV-transformed respiratory cell line to compare adherence of two strains of P. aeruginosa to CF and non-CF respiratory cells. The effect of subinhibitory concentrations of antipseudomonal antibiotics on adherence of P. aeruginosa to cell monolayers was measured.


RESULTS
piliated P. aeruginosa bound significantly better to CF than non-CF-affected cells (P=0.003). Adherence was significantly reduced when organisms were preincubated in subinhibitory concentrations of antibiotics overnight (P<0.001).


CONCLUSIONS
these results support the presence of an altered receptor present on CF-affected cells that binds piliated strains of P. aeruginosa. Bacterial disadherence due to subinhibitory concentrations of antibiotics may partially explain why clinical improvement is observed in CF patients with acute respiratory exacerbations.
Wolter
J M
JM
University of Queensland Department of Medicine, Mater Adult Hospital, South Brisbane, Australia.
McCormack
J G
JG
D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects*; D002461:Cell Line, Transformed; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000382:microbiology; D006801:Humans; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000166:cytology / Q000187:drug effects*; D013045:Species Specificity; D014132:Trachea / Q000166:cytology / Q000187:drug effects / Q000382:microbiology
D000900:Anti-Bacterial Agents