UTI Flashcards
Which of the following bacteria is the most common cause of uncomplicated urinary tract infections (UTIs)?
A) Escherichia coli
B) Staphylococcus saprophyticus
C) Klebsiella pneumoniae
D) Proteus mirabilis
Answer: A) Escherichia coli
Rationale:
E. coli is responsible for 75–90% of cases of acute uncomplicated cystitis in the U.S., making it the most common uropathogen. Other bacteria, such as Staphylococcus saprophyticus, Klebsiella pneumoniae, and Proteus mirabilis, can also cause UTIs but are less frequent.
Which of the following is a major risk factor for recurrent UTI in postmenopausal women?
A) Lack of circumcision
B) Frequent sexual intercourse
C) Use of fluoroquinolones
D) History of premenopausal UTI
Answer: D) History of premenopausal UTI
Rationale:
In postmenopausal women, a history of UTI before menopause, along with anatomic factors affecting bladder emptying (e.g., cystoceles, incontinence, and residual urine), are major risk factors for recurrent UTIs. Frequent sexual intercourse is a known risk factor for UTIs in premenopausal women but not a primary factor in postmenopausal women.
What is the distinguishing clinical feature between cystitis and pyelonephritis?
A) Dysuria
B) Urinary frequency
C) High-grade fever
D) Hematuria
Answer: C) High-grade fever
Rationale:
Fever is the key feature differentiating pyelonephritis from cystitis. While cystitis typically presents with dysuria, frequency, and urgency, pyelonephritis often includes systemic symptoms such as high fever, chills, nausea, vomiting, and flank pain.
Which of the following antibiotics should be avoided for treating uncomplicated cystitis due to its high collateral damage?
A) Nitrofurantoin
B) Fosfomycin
C) Ciprofloxacin
D) TMP-SMX
Answer: C) Ciprofloxacin
Rationale:
Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) are highly effective against UTIs, but they should be avoided for uncomplicated cystitis unless no other options are available due to their broad-spectrum activity, which leads to increased resistance and significant disruption of normal flora.
Which of the following is NOT an indication for treating asymptomatic bacteriuria (ASB)?
A) Pregnant women
B) Patients undergoing urologic surgery
C) Diabetic patients
D) Renal transplant recipients
Answer: C) Diabetic patients
Rationale:
ASB generally does not require treatment except in specific populations: pregnant women, individuals undergoing urologic surgery, and possibly renal transplant recipients or neutropenic patients. Diabetic patients, while at higher risk for UTIs, do not automatically require treatment for ASB unless symptomatic.
What is the recommended first-line treatment for uncomplicated pyelonephritis?
A) Nitrofurantoin
B) Fosfomycin
C) Ciprofloxacin
D) Ceftriaxone
Answer: C) Ciprofloxacin
Rationale:
Fluoroquinolones (e.g., ciprofloxacin) are the first-line therapy for uncomplicated pyelonephritis due to their high effectiveness. Nitrofurantoin and fosfomycin do not reach adequate tissue levels to treat pyelonephritis, while ceftriaxone may be used as an initial IV dose if resistance is a concern.
