title: In vitro evaluation of antibiotic prophylaxis in the prevention of biliary stent blockage.
abstract: BACKGROUND
  Bacterial adherence and biofilm formation are important factors in the blockage of biliary stents. Clinical studies with oral antibiotic prophylaxis to prevent stent blockage have produced conflicting results. The aim of this study was to evaluate the in vitro effect of single antibiotic (ciprofloxacin, ceftazidime, or ampicillin) treatment on adherence of Escherichia coli and Enterococcus to plastic stents.
  
  
  METHODS
  Selected clinical isolates of E coli and Enterococcus were perfused through a modified Robbins device containing segments of polyethylene stents. The stents were removed daily and the number of bacteria attached was measured. The effect of antibiotic treatment on bacterial adherence was tested by the perfusion of individual antibiotics into separate modified Robbins devices using a side-arm adaptor and the results were compared with saline controls.
  
  
  RESULTS
  Compared with the saline controls, ciprofloxacin and ceftazidime caused a 10- to 100-fold reduction in the number of E coli attached to the stents, whereas ampicillin had no effect on adherence of E coli. Ampicillin caused a 5- to 10-fold reduction in Enterococcus adherence but there was no change with ceftazidime. Sustained reduction in E coli adherence was observed with prolonged ciprofloxacin perfusion.
  
  
  CONCLUSIONS
  Timely treatment with appropriate antibiotics reduced bacterial adherence in vitro and may be potentially beneficial in the prevention of stent blockage.
authors.affiliation: Division of Gastroenterology, University of California, Davis Medical Center, Sacramento, California, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Leung
authors.forename: Y L
authors.initials: YL
authors.lastname: Liu
authors.forename: T D
authors.initials: TD
authors.lastname: Desta
authors.forename: E D
authors.initials: ED
authors.lastname: Libby
authors.forename: J F
authors.initials: JF
authors.lastname: Inciardi
authors.forename: K
authors.initials: K
authors.lastname: Lam
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms; D002442:Ceftazidime / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D016983:Enterococcus / Q000187:drug effects* / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D010406:Penicillins / Q000494:pharmacology; D020959:Polyethylene; D015607:Stents
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D002511:Cephalosporins; D010406:Penicillins; D002939:Ciprofloxacin; D000667:Ampicillin; D020959:Polyethylene; D002442:Ceftazidime