Murine Model of Urinary Tract Infection

Mice were inoculated with 10⁸ CFU of UPEC strain CFT073 or K. pneumoniae strain KPPR1 in 50 μl of phosphate-buffered saline, as previously described^{18 (link)}. Mice were anesthetized with tribromoethanol (250 mg/kg). Inoculum was transurethrally-instilled in the urinary bladder with a polyethylene tubing (outer diameter 0.061 mm)-protected needle controlled by a syringe pump (flow rate=100 μl/minute, Braintree Scientific) to avoid vesicoureteral reflux. Urine was collected prior to euthanasia at 6, 24, 48 hours or 7 days post-inoculation by holding the animals above a sterile Petri dish. Organs were removed aseptically after euthanasia, weighed and homogenized. Urine and organ homogenates were diluted, plated, and incubated aerobically at 37°C to determine CFU/g or ml.