A novel rat model of catheter-associated urinary tract infection

The authors aimed to establish a rat model of catheter-associated UTIs using a complete urethral catheter. Bacterial growth in biofilms on urethral catheters was analyzed using standard culture methods to validate this model. A total of 15 rats were divided into the following three groups according to the duration of indwelling catheter placement: a 2-week group (n = 5, group 1), a 4-week group (n = 5, group 2), and a 6-week group (n = 5, group 3). A urethral catheter was inserted with the distal end buried just beneath the urethra, and it was fixed inside of the urethra with a single suture starting at the vagina so that the suture knot was hidden inside of the vagina, preventing the rats from biting it off. A standard culture method was used to analyze bacterial growth in the biofilms. All 15 urethral catheters were intact at the end of the experiment. Pseudomonas aeruginosa, Escherichia coli, Enterococcus spp., Enterococcus faecalis, and Corynebacterium spp. were identified in the biofilms on the urethral catheters. Our rat UTI model consisting of a complete urinary catheter is feasible. Our study may provide fundamental data for future biofilm studies incorporating molecular techniques, and even clinical studies.