title: Alginate overproduction affects Pseudomonas aeruginosa biofilm structure and function.
abstract: During the course of chronic cystic fibrosis (CF) infections, Pseudomonas aeruginosa undergoes a conversion to a mucoid phenotype, which is characterized by overproduction of the exopolysaccharide alginate. Chronic P. aeruginosa infections involve surface-attached, highly antibiotic-resistant communities of microorganisms organized in biofilms. Although biofilm formation and the conversion to mucoidy are both important aspects of CF pathogenesis, the relationship between them is at the present unclear. In this study, we report that the overproduction of alginate affects biofilm development on an abiotic surface. Biofilms formed by an alginate-overproducing strain exhibit a highly structured architecture and are significantly more resistant to the antibiotic tobramycin than a biofilm formed by an isogenic nonmucoid strain. These results suggest that an important consequence of the conversion to mucoidy is an altered biofilm architecture that shows increasing resistance to antimicrobial treatments.
authors.affiliation: Department of Microbiology, Technical University of Denmark, 2800 Lyngby, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Hentzer
authors.forename: G M
authors.initials: GM
authors.lastname: Teitzel
authors.forename: G J
authors.initials: GJ
authors.lastname: Balzer
authors.forename: A
authors.initials: A
authors.lastname: Heydorn
authors.forename: S
authors.initials: S
authors.lastname: Molin
authors.forename: M
authors.initials: M
authors.lastname: Givskov
authors.forename: M R
authors.initials: MR
authors.lastname: Parsek
mesh_terms: D000464:Alginates / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D004352:Drug Resistance, Microbial; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006801:Humans; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014031:Tobramycin / Q000494:pharmacology
chemical_list: D000464:Alginates; D000900:Anti-Bacterial Agents; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D014031:Tobramycin