title: Isolated microorganisms in plastic biliary stents placed for benign and malignant diseases.
abstract: BACKGROUND
  Biliary stenting is a well-established method to treat patients with malignant and benign biliary diseases. However, occlusion of plastic biliary stents is considered as a drawback and bacterial colonization seems to be the key factor in this process.
  
  
  METHODS
  During a 3-year period, 51 plastic biliary stents were extracted from 42 patients. Twenty three stents were inserted for treating malignant and 28 for benign diseases. Stent samples were taken under a strict protocol, and were immediately sent to microbiological laboratory for culturing.
  
  
  RESULTS
  A polymicrobial growth was present in nearly all stents. The most frequently isolated organisms wereEnterococcus spp(74%),Escherichia coli(E. coli) (62%), andKlebsiella spp(58%).E. coliwas more frequently encountered in benign vs. malignant disease (78% vs. 43%, P<0.05).Klebsiella spp,Pseudomonas spp, andCandida sppwere more frequently isolated in occluded vs. non-occluded stents, 68% vs. 37%, 22% vs. 0 and 40% vs. 6% respectively (P<0.05).E. coliandPseudomonas spphad 34% and 50% resistance rate to quinolones respectively.Enterobacter sppexpressed Amp-C derepression in 35%.Enterococcus spp,Klebsiella sppandPseudomonas spphad a low resistance rate.
  
  
  CONCLUSIONS
  Enterococcus spp,E. coliandKlebsiella sppare the most frequently associated organisms in plastic biliary stents. In occluded stentsPseudomonas sppandCandida sppshould be taken into account. Quinolones may not be adequate for the treatment of cholangitis associated with stent occlusion. In patients under chemotherapy for malignancy and stent occlusion-related biliary sepsis, antifungal and enterococcal covering should be considered.
authors.affiliation: First Department of Surgery, Tzaneio General Hospital, Piraeus (Paris Basioukas, Spyros Rizos), Greece.
authors.forename: Paris
authors.initials: P
authors.lastname: Basioukas
authors.affiliation: Second Department of Surgery and Endoscopic Unit, University of Athens, Aretaieio Hospital, Athens (Antonios Vezakis, George Fragulidis, Andreas Polydorou), Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Vezakis
authors.affiliation: Department of Microbiology, Tzaneio General Hospital, Piraeus (Olympia Zarkotou, Katerina Themeli-Digalaki), Greece.
authors.forename: Olympia
authors.initials: O
authors.lastname: Zarkotou
authors.affiliation: Second Department of Surgery and Endoscopic Unit, University of Athens, Aretaieio Hospital, Athens (Antonios Vezakis, George Fragulidis, Andreas Polydorou), Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Fragulidis
authors.affiliation: Department of Microbiology, Tzaneio General Hospital, Piraeus (Olympia Zarkotou, Katerina Themeli-Digalaki), Greece.
authors.forename: Katerina
authors.initials: K
authors.lastname: Themeli-Digalaki
authors.affiliation: First Department of Surgery, Tzaneio General Hospital, Piraeus (Paris Basioukas, Spyros Rizos), Greece.
authors.forename: Spyros
authors.initials: S
authors.lastname: Rizos
authors.affiliation: Second Department of Surgery and Endoscopic Unit, University of Athens, Aretaieio Hospital, Athens (Antonios Vezakis, George Fragulidis, Andreas Polydorou), Greece.
authors.forename: Andreas
authors.initials: A
authors.lastname: Polydorou
keywords: Biliary stents; antibiotic resistance; microbial growth; microorganisms; occlusion