Problem
The patient is a 18 yr old female with a history of a urinary tract infection (UTI) 4 months prior to admission for which she was treated with oral ampicillin without complications. Five days prior to this admission, whe began to note nausea without vomiting. One day later she developed left flank plain, fevers and chills, and increased urinary frequency. She noted foul-smelling urine on the day prior to admission. She presents with a temperature of 101.8oF, and physical examination shows left costovertebral angle tenderness. Urinalysis of a clean-catch urine sample is notable for >50 white blood cells/high power field, 3 to 10 erythrocytes/high power field, and 3+ bacteria. Urine culture is subsequently positive for >100,000 CFU of a gram negative, lactose-fermenting rod/ml; this bacterium was indole positive. What do the urinalysis findings indicate? Explain your answer. The bacterium responsible for the infection is the most common cause of UTI's. What is this pathogen? How do the biochemical reactions help in the diagnosis? Why are urinary tract infections more common in women than in men? Did this woman have cystitis or pyelonephritis? Why is it important to differentiate?