title: The pulmonary clearance of smooth and rough strains of Pseudomonas aeruginosa.
abstract: Upper airway colonization with rough strains of Pseudomonas is associated with clinical deterioration in patients with cystic fibrosis. These rough strains are less toxic than smooth strains in the burned mouse model and in vitro assays. We measured the 4-h pulmonary clearance of 10(4) and 10(6) rough and smooth Pseudomonas after intrabronchial inoculation. After 10(4) Pseudomonas, rough strains were cleared more efficiently than smooth strains (89 +/- 13% versus 140 +/- 19% of the original inoculum, respectively, p less than 0.05). This was associated with more total bronchoalveolar lavage PMNs after inoculation with rough as compared with smooth Pseudomonas (1.60 +/- 0.38 x 10(5) versus 0.55 +/- 0.09 x 10(5), respectively, p less than 0.05). After inoculation with 10(6) Pseudomonas, rough were cleared less efficiently than smooth Pseudomonas (380 +/- 45% versus 134 +/- 12% of the original inoculum, respectively, p less than 0.05). There was no difference in the BAL PMNs of the animals inoculated with either bacterial strain at this inoculum (8.1 +/- 0.6 x 10(5) and 9.4 +/- 1.0 x 10(5) for the rough and smooth Pseudomonas, respectively). When PMN differences were abolished in C5-deficient mice, 10(4) rough were cleared less efficiently than smooth Pseudomonas. The relatively poor clearance of rough Pseudomonas could not be explained by in vitro differences in PMN killing or BAL toxicity or by intrinsic growth rates.
authors.affiliation: Department of Medicine, Northwestern University Medical School, Chicago, IL 60611.
authors.forename: H G
authors.initials: HG
authors.lastname: Martin
authors.forename: J R
authors.initials: JR
authors.lastname: Warren
authors.forename: M M
authors.initials: MM
authors.lastname: Dunn
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D003550:Cystic Fibrosis / Q000382:microbiology; D008168:Lung / Q000276:immunology / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009079:Mucociliary Clearance; D009504:Neutrophils / Q000276:immunology; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000276:immunology*; D013997:Time Factors