title: Bacterial adhesion to surfactant-modified silicone surfaces.
abstract: OBJECTIVE
  Ventricular shunt infections are a major contributor to morbidity in patients being treated for hydrocephalus. The majority of these infections are from Staphylococcus epidermidis. Prevention of bacterial adhesion to the silicone surface of a ventricular catheter could decrease shunt infections. We studied the effectiveness of a surfactant and/or 2% iodine prewash on preventing bacterial adhesion to Silastic catheter material.
  
  
  METHODS
  In a laboratory setting, various concentrations of a surfactant, Poloxamer-188 (P188), and a bactericidal agent, iodine, were compared against a control solution in their ability to prevent bacterial adhesion of S. epidermidis to a silicone surface. Silicone wafers were soaked for 1 hour in the test solution, then inoculated and incubated with S. epidermidis for 24 hours. Bacterial counts were then obtained and compared.
  
  
  RESULTS
  The most effective method tested in this study was 20% P188, which allowed only 3.02% bacterial adhesion compared with 22.2% bacterial adhesion in the control (P < 0.001). P188 at a 10% concentration or 20% mixed with iodine had the next most effective inhibition. Of the germicidal solutions, a 5-ppm solution of iodine was the most effective. The most ineffective method tested was 2 ppm iodine, which allowed 13.2% bacterial adhesion.
  
  
  CONCLUSIONS
  Use of a surfactant and/or a germicidal will provide some protection against bacteria attaching to silicone surfaces before they are surgically implanted. The use of a surfactant soak of 20% P188 or iodine at a concentration of 5 ppm before inoculation with S. epidermidis significantly decreased the bacterial adhesion to silicone wafers. This finding has relevance to clinical practice because it highlights a simple step undertaken before implanting a ventricular catheter that could reduce the adhesion rate of the most common contaminant of these catheters. This step may become an important factor in decreasing infection rates in shunt-dependent patients.
authors.affiliation: Division of Neurosurgery, Children's Hospital of San Diego, Suite 300, 8010 Frost Street, San Diego, CA 92123, USA. mlevy@chsd.org
authors.forename: Michael L
authors.initials: ML
authors.lastname: Levy
authors.forename: Truc
authors.initials: T
authors.lastname: Luu
authors.forename: Hal S
authors.initials: HS
authors.lastname: Meltzer
authors.forename: Rebecca
authors.initials: R
authors.lastname: Bennett
authors.forename: Derek A
authors.initials: DA
authors.lastname: Bruce
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects*; D015169:Colony Count, Microbial; D003470:Culture Media; D007455:Iodine / Q000494:pharmacology*; D020442:Poloxamer / Q000494:pharmacology*; D012825:Silicon; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000502:physiology; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D000891:Anti-Infective Agents, Local; D003470:Culture Media; D013501:Surface-Active Agents; D020442:Poloxamer; D007455:Iodine; D012825:Silicon