title: Adherence and kinetics of biofilm formation of Staphylococcus epidermidis to different types of intraocular lenses under dynamic flow conditions.
abstract: OBJECTIVE
  To compare the adherence and biofilm formation of Staphylococcus epidermidis under in vitro flow conditions on intraocular lenses (IOLs) made of 4 biomaterials: poly(methyl methacrylate) (PMMA), silicone, hydrophilic acrylic, and hydrophobic acrylic.
  
  
  METHODS
  Department of Ophthalmology, Croix-Rousse University Hospital and University Research Laboratory, Lyon, France.
  
  
  METHODS
  Intraocular lenses were placed in a bioreactor designed to replicate intraocular conditions. The model consisted of Tygon tubing connected to a vial. Three septa allowed the entry and elimination of the artificial aqueous humor and inoculation of the bacterial suspension. The first of 2 pumps moved the aqueous humor along the circuit; the second pump regulated the flow at which the nutritive environment was regenerated. At various times (12, 16, 24, 40, 48, 60, and 72 hours), IOLs were taken from this environment and the bound bacteria were removed and counted. The distribution of bacterial adhesion on the IOLs was modeled using polynomial Poisson regression. To test the effect of the IOL biomaterial on bacterial adhesion, likelihood ratio tests were performed.
  
  
  RESULTS
  The model provided the kinetics of S epidermidis biofilm growth on IOLs. The biofilm growth on each of the 4 biomaterials occurred in 3 phases: latent, dynamic or accelerated growth, and linear growth. The extent of bacterial binding to IOLs increased from hydrophilic acrylic polymer to PMMA, hydrophobic acrylic, and silicone. The differences were statistically significant.
  
  
  CONCLUSIONS
  Bacterial adhesion to and biofilm development on the IOL surface depended on the characteristics of the biomaterial.
authors.affiliation: Department of Ophthalmology, Croix-Rousse University Hospital, Lyon, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Baillif
authors.forename: René
authors.initials: R
authors.lastname: Ecochard
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Casoli
authors.forename: Jean
authors.initials: J
authors.lastname: Freney
authors.forename: Carole
authors.initials: C
authors.lastname: Burillon
authors.forename: Laurent
authors.initials: L
authors.lastname: Kodjikian
mesh_terms: D000180:Acrylic Resins; D001082:Aqueous Humor / Q000378:metabolism*; D001422:Bacterial Adhesion / Q000502:physiology*; D001672:Biocompatible Materials; D018441:Biofilms / Q000254:growth & development*; D015169:Colony Count, Microbial; D007700:Kinetics; D007910:Lenses, Intraocular / Q000382:microbiology*; D019904:Polymethyl Methacrylate; D012826:Silicone Elastomers; D013212:Staphylococcus epidermidis / Q000502:physiology*
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D012826:Silicone Elastomers; D019904:Polymethyl Methacrylate