Fibrinogen release and deposition on urinary catheters placed during urologic procedures

Catheter-associated urinary tract infections (CAUTI) account for ∼40% of all hospital-acquired infections worldwide, with more than one million cases diagnosed annually. Recent data from a CAUTI animal model has shown that inflammation induced by catheterization releases host fibrinogen that accumulates on the catheter.

Further, Enterococcus faecalis catheter colonization was found to be dependent on EbpA, a fibrinogen binding adhesin. We sought to evaluate this mechanism in a human model.

Urinary catheters were collected from human subjects hospitalized for surgical or non-surgical urologic procedures. Catheters were subjected to immunofluorescence analyses by incubating them with anti-fibrinogen antibody and then stained for fluorescence. The fluorescence intensity was compared to standard catheters. Catheters were incubated with strains of Enterococcus faecalis, Staphylococcus aureus, or Candida to assess their binding to fibrinogen-laden catheters.

Fifty catheters were collected after various surgical and urological procedures. In vivo dwell time ranged from 1 hour to 59 days. All catheters had fibrinogen deposition and its accumulation was dependent on dwell time but not on surgical procedure or catheter material. Catheters were probed ex vivo with E. faecalis, S. aureus, and Candida albicans, which bound to catheters only in those regions where fibrinogen was deposited.

Taken together, these data show that urinary catheters act as a binding surface for accumulation of fibrinogen, which is released due to inflammation resulting from a urological procedure or from catheter placement, creating a niche that can be exploited by uropathogens to cause CAUTI.

The Journal of urology. 2016 Jan 28 [Epub ahead of print]

Ana L Flores-Mireles, Jennifer N Walker, Tyler M Bauman, Aaron M Potretzke, Henry L Schreiber, Alyssa M Park, Jerome S Pinkner, Michael G Caparon, Scott J Hultgren, Alana Desai

Department of Molecular Microbiology; Center for Women's Infectious Disease Research. , Department of Molecular Microbiology; Center for Women's Infectious Disease Research. , Division of Urologic Surgery, Washington University School of Medicine, Saint Louis, MO 63110-1093, USA. , Division of Urologic Surgery, Washington University School of Medicine, Saint Louis, MO 63110-1093, USA. , Department of Molecular Microbiology; Center for Women's Infectious Disease Research. , Division of Urologic Surgery, Washington University School of Medicine, Saint Louis, MO 63110-1093, USA. , Department of Molecular Microbiology; Center for Women's Infectious Disease Research. , Department of Molecular Microbiology; Center for Women's Infectious Disease Research. , Department of Molecular Microbiology; Center for Women's Infectious Disease Research. , Division of Urologic Surgery, Washington University School of Medicine, Saint Louis, MO 63110-1093, USA. 

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