PURPOSE: Catheter-associated urinary tract infections (CAUTI) are one of the most common healthcare-associated infections frequently complicated by encrustation, causing blockage of the catheter lumen.
Preclinical research is limited by the lack of relevant high-throughput and cost effective animal models. Current models are restricted to female mice, associated with major transurethral loss of catheter materials during micturition, highly invasive and complex. We present an ultrasound-guided, minimally-invasive model enabling CAUTI and catheter encrustation studies in both genders of mice.
MATERIALS AND METHODS: Implantation of 4mm catheter segments into murine bladders was performed percutaneously (n=15 males; n=5 females) or transurethrally (n=15 females) using the Seldinger technique under ultrasound guidance. Proteus mirabilis was instilled intraluminally. Catheter encrustation was monitored by ultrasound. Bacteria were quantified from urine and catheters and encrustation analyzed on days 6 or 21.
RESULTS: Percutaneous and transurethral catheter implantations were performed efficiently (mean time: 3.6±0.8min vs 2.5±0.5min) in all animals. Ultrasound confirmed that 100% vs 66%, of implanted catheters remained indwelling over the study period. Catheter encrustation developed in P.mirabilis-infected urine 48h post instillation and its increase over time was detectable with ultrasonography. FTIR analysis of the encrustation confirmed a typical struvite spectrum. Control catheters remained sterile over 21 days.
CONCLUSIONS: Our minimally-invasiveand reproducible percutaneous technique is suitable to study CAUTI in both genders. Infecting urine with P.mirabilis generates a preclinical model of catheter encrustation within 3 days. The progression of encrustation can be monitored in vivo using ultrasonography, making this image-based model suitable to assess novel antibacterial and anti-encrustation therapies.
Janssen C, Lo J, Jäger W, Moskalev I, Law A, Chew BH, Lange D. Are you the author?
The Stone Centre at Vancouver General Hospital, Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada; Department of Urology, Johannes Gutenberg University, Mainz, Germany; Department of Urology, Johannes Gutenberg University, Mainz, Germany; Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.
Reference: J Urol. 2014 May 24. pii: S0022-5347(14)03685-4.