title: Biofilm formation by Enterococcus faecalis on intraocular lens material.
abstract: OBJECTIVE
  To compare biofilm formation by Enterococcus faecalis on different intraocular lens (IOL) materials.
  
  
  METHODS
  E. faecalis biofilms were cultivated on disks of IOL material (silicone, PMMA [polymethylmethacrylate], or acrylic). Biofilms were stained with crystal violet (CV), which served as an index of biofilm formation. The bacterial population was enumerated after biofilm homogenization. Biofilms were also examined by confocal microscopy.
  
  
  RESULTS
  At 24 hr, there was no significant difference in biofilm formation, or the population within biofilms, among the three materials tested. However, after 48 and 72 hr, it was observed that silicone supported the least amount of biofilm formation (p < 0.05); biomass on PMMA and acrylic IOLs continued to increase, with acrylic demonstrating the greatest amount of stainable biofilm (p < 0.0005). The population on PMMA was significantly greater than the other IOL materials (p < 0.005). Confocal microscopy confirmed the lack of biomass on silicone.
  
  
  CONCLUSIONS
  Among three IOL materials, E. faecalis biofilms formed more readily on PMMA and acrylic compared to silicone.
authors.affiliation: Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kobayakawa
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Jett
authors.forename: Michael S
authors.initials: MS
authors.lastname: Gilmore
mesh_terms: D000180:Acrylic Resins; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000502:physiology*; D007910:Lenses, Intraocular / Q000382:microbiology*; D018613:Microscopy, Confocal; D019904:Polymethyl Methacrylate; D012826:Silicone Elastomers
chemical_list: D000180:Acrylic Resins; D012826:Silicone Elastomers; D019904:Polymethyl Methacrylate