Review Question - QID 106731

This patient presents with a urinary tract infection (UTI), most likely caused by E. coli. The P fimbriae virulence factor of E. coli enables binding to uroepithelial cells and allows for cystitis and pyelonephritis.

UTIs are infections affecting the lower or upper urinary tract. They are often referred to as "honeymoon cystitis" due to their association with increased sexual activity. Common symptoms of lower UTIs include increased frequency, dysuria, and increased urge. E. coli is the most common cause of UTIs, followed, in order, by Staphylococcus saprophyticus and Klebsiella pneumoniae. E. coli contains a number of virulence factors including fimbriae, K capsule, and LPS endotoxin. The P fimbriae virulence factor of E. coli enables binding to uroepithelial cells, leading to cystitis and pyelonephritis. Treatment of UTI is most commonly with antibiotics such as trimethoprim-sulfamethoxazole.

Incorrect Answers:
Answer 1: The LPS endotoxin of E. coli is the virulence factor which contributes to septic shock.
Answer 2: The K capsule of E. coli is the virulence factor which contributes to pneumonia and neonatal meningitis.
Answer 4: The majority of E. coli strains do not possess a flagella. Furthermore, flagella presence would not contribute to the pathogenesis of UTIs.
Answer 5: Exotoxin produced by E. coli contributes to its gastrointestinal pathogenicity (ex: EHEH, Shiga-like toxin) but does contribute to the pathogenesis of UTI's.