title: Pseudomonas aeruginosa chronic colonization in cystic fibrosis patients.
abstract: OBJECTIVE
  Chronic infection with Pseudomonas aeruginosa is a leading cause of morbidity and mortality in individuals with cystic fibrosis despite the aggressive use of antibiotics. P. aeruginosa employs a number of strategies that promote chronic pulmonary colonization instead of acute infection. These include biofilm formation, evasion of the host immune system, and conversion to a mucoid phenotype. This review discusses recent advances regarding P. aeruginosa pathogenesis and biofilm behavior in the setting of chronic pulmonary disease.
  
  
  RESULTS
  Biofilm formation in the cystic fibrosis lung likely occurs under anaerobic conditions, is controlled by bacterial quorum-sensing mechanisms, and is enhanced by environmental components in the cystic fibrosis airway. P. aeruginosa possesses regulatory pathways that recognize environmental cues to favor either acute infection or chronic colonization. P. aeruginosa that inhabit the respiratory tract accumulate mutations favoring chronic colonization. Azithromycin, a macrolide with clinical benefit in cystic fibrosis, alters P. aeruginosa biofilm formation. Promising new therapies that target biofilm formation include molecules that disrupt quorum sensing.
  
  
  CONCLUSIONS
  Eradication of P. aeruginosa in cystic fibrosis patients remains problematic. As more information emerges about P. aeruginosa behavior in vivo, potential therapeutics directed against biofilms and mucoid P. aeruginosa are being developed.
authors.affiliation: Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8022, USA. thomas.s.muray@yale.edu
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Murray
authors.forename: Marie
authors.initials: M
authors.lastname: Egan
authors.forename: Barbara I
authors.initials: BI
authors.lastname: Kazmierczak
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects; D001988:Bronchiolitis / Q000188:drug therapy / Q000382:microbiology; D002648:Child; D003550:Cystic Fibrosis / Q000382:microbiology*; D006801:Humans; D008168:Lung / Q000382:microbiology*; D018942:Macrolides / Q000494:pharmacology / Q000627:therapeutic use*; D009093:Mucus / Q000382:microbiology; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000472:pathogenicity*; D015398:Signal Transduction; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides