title: Impact of bacterial biofilm formation on in vitro and in vivo activities of antibiotics.
abstract: The impact of bacterial adherence on antibiotic activity was analyzed with two isogenic strains of Staphylococcus epidermidis that differ in the features of their in vitro biofilm formation. The eradication of bacteria adhering to glass beads by amikacin, levofloxacin, rifampin, or teicoplanin was studied in an animal model and in a pharmacokinetically matched in vitro model. The features of S. epidermidis RP62A that allowed it to grow on surfaces in multiple layers promoted phenotypic resistance to antibiotic treatment, whereas strain M7 failed to accumulate, despite initial adherence on surfaces and growth in suspension similar to those for RP62A. Biofilms of S. epidermidis M7 were better eradicated than those of strain RP62A in vitro (46 versus 31%; P < 0.05) as well as in the animal model (39 versus 9%; P < 0.01).
authors.affiliation: Department of Internal Medicine, University Hospital Zurich, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Schwank
authors.forename: Z
authors.initials: Z
authors.lastname: Rajacic
authors.forename: W
authors.initials: W
authors.lastname: Zimmerli
authors.forename: J
authors.initials: J
authors.lastname: Blaser
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D003470:Culture Media; D004352:Drug Resistance, Microbial; D006168:Guinea Pigs; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media