Category: Basic Science: Stones

MP2-17 - Conditioning film components on ureteral stents provide bacterial binding sites- a possible mechanism of stent-related urinary tract infection

Thu, Sep 20
4:00 PM - 6:00 PM

Introduction & Objective : Indwelling ureteral stents are thought to serve as a nidus for infection. The mechanism underlying stent-associated infection has been postulated to involve the formation of a conditioning film—a layer of extracellular material from the deposition of urinary constituents. Bacteria have been shown to associate with elements of this conditioning film, thus resulting in biofilm. We previously identified some of the constituents of stent-bound conditioning film. We now investigate the distribution of the most common components, fibrinogen, uromodulin, and albumin and their interaction with common bacterial uropathogens. We aimed to better characterize the distribution of the conditioning film and associated bacterial biofilm across the stent material surface. We hypothesized that bacteria would bind to common conditioning film components on stents removed from patients.

Methods : Indwelling ureteral stents were obtained from patients after cystoscopic removal. Stents were incubated with Escherichia coli, Enterococcus faecalis or Staphylococcus aureus. Immunofluorescence experiments were performed to identify and localize binding of these bacteria to the conditioning film components fibrinogen, uromodulin and albumin.

Results : Binding of fibrinogen, uromodulin and albumin to stents was demonstrated with adherence of the bacteria at similar stent locations. Biofilm deposition was noted to be non-uniform. Conditioning film components attached preferentially to the outer stent surface with minimal deposition in the inner lumen.

Conclusions : We have confirmed co-localization of bacterial species and conditioning film components on ureteral stents. Understanding this binding process will improve our approach to novel stent development and prevention of stent associated infections.

Kymora B. Scotland

Endourology Fellow
University of British Columbia
Vancouver, British Columbia, Canada

Ryan Paterson

Vancouver, British Columbia, Canada

Ben H. Chew

Associate Professor, Department of Urologic Sciences
University of British Columbia
Vancouver, British Columbia, Canada

Dr. Chew is a urologist and the Director of Clinical Research at the Stone Centre at Vancouver General Hospital and an Associate Professor of Urology at the University of British Columbia in Vancouver, Canada. His main interests lie in the treatment and research of the pathophysiology of kidney stone disease. His research focus includes metabolic stone disease as well as biomaterials used in the urinary tract for ureteral stents. He has worked on various stent designs, stent coatings and drug-eluting ureteral stents to try and improve the quality of life for patients with kidney stone disease. He continues work on a degradable ureteral stent and has completed the first-in-human trials. Current studies include attempting to understand second messenger systems that are activated within the kidney and ureter once a ureteral stent has been placed. These could be exploited as future therapeutic targets for new drug eluting ureteral stents or designs to reduce symptoms.
He has authored over 80 peer-reviewed manuscripts and book chapters. He is a member of the Endourologic Disease Group for Excellence (EDGE) research consortium ( and the Wisconsin Quality of Life (WISQoL) research consortium. Dr. Ben Chew is also the Chair of Research for the Endourology Society. The role of the Research Chair is to facilitate and help improve research for the entire society.

Dirk Lange

Associate Professor
Dept. of Urologic Sciences, University of British Columbia
Vancouver, British Columbia, Canada