Establishment of a Urinary Tract Infection Model in Female Mice

After anesthetizing a female mouse, according to an approved protocol, place the animal supine, and apply medium pressure to the lower abdomen to empty the bladder of urine. Full bladders feel like a pea under the skin between the iliac crests.

When the bladder is empty, using the non-dominant hand, place the thumb on the tail and a finger of the same hand on the abdomen of the mouse, and apply gentle pressure in opposing directions to hold the mouse firmly in place. Next, place the tip of the catheter perpendicular to the mouse at the urethral orifice. Then, with gentle pressure, slide the catheter into the urethra until the hub meets the urethral orifice while simultaneously lowering the syringe so that it is parallel to the working surface.

Once the catheter is in place, use a finger from the non-dominant hand that's resting on the mouse's abdomen to very gently pull the abdominal skin towards the head of the mouse. Note that the urethral orifice will not move. However, if the catheter is in the vagina, the tissue will move up and away from the catheter. With the hub of the catheter against the urethral orifice, slowly dispense 50 microliters of the bacterial inoculum.

A slow installation rate minimizes vesicoureteral reflux into the kidney. Slowly remove the catheter to prevent leakage, then, place the animal in its cage in a supine position.