Establishing Lower Urinary Tract Candidiasis in Swiss Webster Mice

Introduction: Urinary tract infections caused by Candida species are common in immunosuppressed patients in hospital and assisted-living settings, The purpose of this study was to establish and characterize a urinary tract Candida albicans infection in mice that could be used to evaluate antifungal drugs for treating this infection. Methods: Swiss Webster mice were immunosuppressed with cyclophosphamide d-3, sedated and challenged d0 with 1.8X10ex5 C. albicans using an intraurinary catheter. Tissues were collected from subgroups of mice each day (n=5/day) up to day +5 to monitor fungal burdens over time. Bladder, liver, spleen, and kidneys were homogenized and plated on Sabouraud's dextrose agar to determine fungal load (CFU/g). Results: On d+1, the highest fungal burden was in the kidneys (4.1 X 10ex3), with lower, but similar levels, in the bladder, liver and spleen. From d+2 to d+5 the fungal burden in the bladder and kidneys was higher (2.1 X 10ex3 and 4.1 X 10ex4, respectively) than in the liver and spleen (7.5 X 10ex0 and 1.4 X 10ex1, respectively). Notably, by d+5, there was no detectable yeast in the liver and spleen although there was still a lot of infection in the bladder and kidneys (5.1 X 10ex4 and 1.1 X 10ex3, respectively). Conclusion: We were able to establish a urinary tract infection in immunosuppressed mice which could be sustained in the bladder and kidneys over a 5 day period. Thus, this urinary tract model can be used to evaluate antifungal drug regimens to treat this infection. Keywords: urinary tract, Candida, mouse mode