title: Escherichia coli adhesion, biofilm development and antibiotic susceptibility on biomedical materials.
abstract: The aim of this work was to test materials typically used in the construction of medical devices regarding their influence in the initial adhesion, biofilm development and antibiotic susceptibility of Escherichia coli biofilms. Adhesion and biofilm development was monitored in 12-well microtiter plates containing coupons of different biomedical materials--silicone (SIL), stainless steel (SS) and polyvinyl chloride (PVC)--and glass (GLA) as control. The susceptibility of biofilms to ciprofloxacin and ampicillin was assessed, and the antibiotic effect in cell morphology was observed by scanning electron microscopy. The surface hydrophobicity of the bacterial strain and materials was also evaluated from contact angle measurements. Surface hydrophobicity was related with initial E. coli adhesion and subsequent biofilm development. Hydrophobic materials, such as SIL, SS, and PVC, showed higher bacterial colonization than the hydrophilic GLA. Silicone was the surface with the greatest number of adhered cells and the biofilms formed on this material were also less susceptible to both antibiotics. It was found that different antibiotics induced different levels of elongation on E. coli sessile cells. Results revealed that, by affecting the initial adhesion, the surface properties of a given material can modulate biofilm buildup and interfere with the outcome of antimicrobial therapy. These findings raise the possibility of fine-tuning surface properties as a strategy to reach higher therapeutic efficacy.
authors.affiliation: LEPABE - Department of Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, Porto, Portugal.
authors.forename: L C
authors.initials: LC
authors.lastname: Gomes
authors.forename: L N
authors.initials: LN
authors.lastname: Silva
authors.forename: M
authors.initials: M
authors.lastname: Simões
authors.forename: L F
authors.initials: LF
authors.lastname: Melo
authors.forename: F J
authors.initials: FJ
authors.lastname: Mergulhão
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects / Q000502:physiology*; D001672:Biocompatible Materials / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002470:Cell Survival / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D010933:Plankton / Q000187:drug effects / Q000254:growth & development; D013499:Surface Properties; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials
keywords: Escherichia coli; antibiotic susceptibility; bacterial adhesion; biofilm formation; surface hydrophobicity