Pyelonephritis: The Daily PANCE Blueprint

The answer is A) Escherichia coli

The patient’s presentation is consistent with acute pyelonephritis, characterized by symptoms such as fever, flank pain, and urinary symptoms, along with laboratory findings of pyuria. The most common cause of acute pyelonephritis is Escherichia coli, accounting for the majority of cases. This gram-negative bacterium is a frequent colonizer of the gastrointestinal tract and can ascend the urinary tract, leading to infection.

Incorrect Answer Explanations:

• B) Klebsiella pneumoniae: While Klebsiella species are a cause of urinary tract infections, they are less common than E. coli and are more often associated with hospital-acquired infections.
• C) Staphylococcus saprophyticus: This organism is a common cause of urinary tract infections in sexually active young women but is less common than E. coli and is not typically associated with acute pyelonephritis.
• D) Pseudomonas aeruginosa: This pathogen is more commonly associated with hospital-acquired infections and infections in patients with structural abnormalities of the urinary tract or those who have undergone recent instrumentation, not typically the primary cause in otherwise healthy individuals.
• E) Enterococcus faecalis: Enterococci can cause urinary tract infections, particularly in older adults and in healthcare settings, but they are not the most common cause of acute pyelonephritis in otherwise healthy young women.