title: Pseudomonas aeruginosa in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Pseudomonas aeruginosa is isolated from adults with chronic obstructive pulmonary disease (COPD) in cross-sectional studies. However, patterns of carriage and the role of P. aeruginosa in COPD are unknown.
  
  
  OBJECTIVE
  To elucidate carriage patterns, phenotypes of strains, clinical manifestations, and the antibody response to P. aeruginosa in COPD.
  
  
  METHODS
  A prospective study of adults with COPD was conducted. Isolates of P. aeruginosa were subjected to genotypic and phenotypic analysis. Sputum samples were studied for P. aeruginosa DNA, and immune responses were assayed.
  
  
  RESULTS
  We analyzed longitudinal clinical data, sputum cultures, pulsed-field gel electrophoresis of bacterial DNA, polymerase chain reaction of sputum, and immunoblot assays of serum. Fifty-seven episodes of acquisition of strains of P. aeruginosa were observed in 39 of 126 patients over 10 years. Acquisition of a new strain was associated with exacerbation. Thirty-one episodes of carriage were followed by clearance of the strain; 16 were of short (<1 mo) duration. Thirteen strains demonstrated persistence, and 13 strains were of indeterminate duration. Six strains were mucoid and were more likely to persist than nonmucoid strains (P = 0.005). Antibody responses developed in 53.8% of persistent carriage and in only 9.7% of short-term carriage episodes (P = 0.003). Antibiotics did not account for clearance.
  
  
  CONCLUSIONS
  Two distinct patterns of carriage by P. aeruginosa were observed: (1) short-term colonization followed by clearance and (2) long-term persistence. Mucoid strains showed persistence. Acquisition of P. aeruginosa is associated with the occurrence of an exacerbation. Serum antibody responses do not mediate clearance of P. aeruginosa.
authors.affiliation: Medical Research 151, Buffalo Veterans Affairs Medical Center, 3495 Bailey Avenue, Buffalo, NY 14215, USA. murphyt@buffalo.edu
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Murphy
authors.forename: Aimee L
authors.initials: AL
authors.lastname: Brauer
authors.forename: Karen
authors.initials: K
authors.lastname: Eschberger
authors.forename: Phyllis
authors.initials: P
authors.lastname: Lobbins
authors.forename: Lori
authors.initials: L
authors.lastname: Grove
authors.forename: Xueya
authors.initials: X
authors.lastname: Cai
authors.forename: Sanjay
authors.initials: S
authors.lastname: Sethi
mesh_terms: D000368:Aged; D002353:Carrier State / Q000276:immunology / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006787:Hospitals, Veterans; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D010641:Phenotype; D011552:Pseudomonas Infections / Q000145:classification / Q000503:physiopathology*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000276:immunology / Q000472:pathogenicity*; D029424:Pulmonary Disease, Chronic Obstructive / Q000382:microbiology* / Q000503:physiopathology; D013183:Sputum / Q000382:microbiology*