title: Prevention of initial biofilm formation on ureteral stents using a sustained releasing varnish containing chlorhexidine: in vitro study.
abstract: OBJECTIVE
  Ureteral stents are being used exceedingly in the field of urology, and with advancements in endourology, this trend is increasing. Bacterial colonization and proliferation on the stent surface may result in urinary tract infections (UTIs) necessitating the administration of antibiotics that, in turn, may lead to the development of antibiotic-resistant bacterial strains. Several studies have shown that sustained release varnish (SRV) combined with antibiotics or antiseptics can prevent the proliferation of bacteria on urethral catheters. This is the first study that evaluates this technique implemented on ureteral stents.
  
  
  METHODS
  We evaluated growth inhibition on ureteral stent segments coated with chlorhexidine (CHX) 1% SRV. The tests were conducted using common urinary pathogens: Enterococci, Pseudomonas, and Escherichia coli. Coated stent segments were inserted into bacterial suspensions. Controls included uncoated stent segments and stents coated with placebo SRV (without CHX).
  
  
  RESULTS
  Bacterial growth measured as turbidity and as colony-forming units showed a significant inhibition effect of initial bacteria adhesion to the CHX-SRV coated stent segments compared with the controls (P<0.001). This inhibitory effect was apparent in each of the bacteria tested and was confirmed by inspection of the stent segments under an electron microscope. In a kinetic experiment using CHX 2% SRV, we were able to prolong the growth inhibition effect from 1 week to nearly 2 weeks.
  
  
  CONCLUSIONS
  We believe this technique may play a significant role in reducing ureteral stent-associated UTIs. Further studies are needed before this approach can be implemented in clinical practice.
authors.affiliation: Department of Urology, Hadassah Medical Center, The Hebrew University, Ein Kerem, Jerusalem, Israel.
authors.forename: Genady
authors.initials: G
authors.lastname: Zelichenko
authors.forename: Doron
authors.initials: D
authors.lastname: Steinberg
authors.forename: Gideon
authors.initials: G
authors.lastname: Lorber
authors.forename: Michael
authors.initials: M
authors.lastname: Friedman
authors.forename: Batia
authors.initials: B
authors.lastname: Zaks
authors.forename: Eran
authors.initials: E
authors.lastname: Lavy
authors.forename: Guy
authors.initials: G
authors.lastname: Hidas
authors.forename: Ezekiel H
authors.initials: EH
authors.lastname: Landau
authors.forename: Ofer N
authors.initials: ON
authors.lastname: Gofrit
authors.forename: Dov
authors.initials: D
authors.lastname: Pode
authors.forename: Mordechai
authors.initials: M
authors.lastname: Duvdevani
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002710:Chlorhexidine / Q000494:pharmacology*; D020099:Coated Materials, Biocompatible / Q000494:pharmacology; D015169:Colony Count, Microbial; D003692:Delayed-Action Preparations; D013293:Enterococcus faecalis / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D010150:Paint; D016459:Prosthesis-Related Infections / Q000382:microbiology* / Q000517:prevention & control*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D015607:Stents / Q000382:microbiology*; D014513:Ureter / Q000187:drug effects*
chemical_list: D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D002710:Chlorhexidine