What is the recommended treatment for an E. coli (Escherichia coli) urinary tract infection (UTI)?

Treatment for E. coli Urinary Tract Infection (UTI)

For uncomplicated E. coli UTIs, first-line treatment options include nitrofurantoin, fosfomycin, or trimethoprim-sulfamethoxazole (if local resistance is <20%), with fluoroquinolones reserved as second-line options due to increasing resistance concerns. 1

Treatment Algorithm for Uncomplicated UTIs

• Check local resistance patterns before selecting empiric therapy, as this significantly impacts treatment success 1

• First-line options:

  • Nitrofurantoin for 5 days 1
  • Fosfomycin tromethamine as a single 3g dose 1
  • Trimethoprim-sulfamethoxazole (160/800mg twice daily) if local resistance is <20% and patient has not used this antibiotic in the previous 3-6 months 1, 2

• Second-line options (when first-line options cannot be used):

  • Oral cephalosporins such as cephalexin or cefixime 1
  • Fluoroquinolones (only if local resistance <10% and patient has not used fluoroquinolones in the last 6 months) 3, 4
  • Amoxicillin-clavulanate 1, 5

Treatment for Complicated UTIs and Pyelonephritis

• For complicated UTIs with systemic symptoms, recommended empirical treatment includes: 3

  • Amoxicillin plus an aminoglycoside
  • A second-generation cephalosporin plus an aminoglycoside
  • An intravenous third-generation cephalosporin

• For pyelonephritis: 1

  • Oral fluoroquinolone (ciprofloxacin 500mg twice daily for 7 days) if local resistance <10%
  • Trimethoprim-sulfamethoxazole (160/800mg twice daily for 14 days) only if susceptibility is confirmed
  • If using oral β-lactams, start with an initial IV dose of ceftriaxone 1g or aminoglycoside

• For hospitalized patients with pyelonephritis: 1

  • Initial IV therapy with fluoroquinolone, aminoglycoside (with/without ampicillin), extended-spectrum cephalosporin/penicillin, or carbapenem
  • Tailor therapy based on culture and susceptibility results

Duration of Treatment

• Uncomplicated cystitis: 5 days for nitrofurantoin, single dose for fosfomycin 1
• Complicated UTIs: 7-14 days (14 days for men when prostatitis cannot be excluded) 3
• When the patient is hemodynamically stable and has been afebrile for at least 48 hours, a shorter treatment duration (e.g., 7 days) may be considered 3

Special Considerations

Multidrug-Resistant E. coli

• For ESBL-producing E. coli, consider nitrofurantoin, fosfomycin, pivmecillinam, or carbapenems based on susceptibility testing 5
• For carbapenem-resistant E. coli, options include ceftazidime-avibactam, meropenem-vaborbactam, or imipenem-cilastatin-relebactam 1

Recurrent UTIs

• E. coli causing persistence or relapse are more often from phylogenetic group B2 and have higher virulence factor scores 6
• Biofilm formation capacity is higher in E. coli strains causing persistence or relapse, suggesting this may be an important determinant for developing recurrent UTIs 6
• For recurrent UTIs, consider prophylactic strategies, including post-coital antibiotics for premenopausal women with infection related to sexual activity 1

Common Pitfalls to Avoid

• Using fluoroquinolones as first-line therapy for uncomplicated UTIs due to increasing resistance and risk of adverse effects 1, 4
• Not obtaining urine culture before treatment in patients with recurrent UTIs, complicated UTIs, or risk factors for resistant organisms 1
• Using antibiotics with known high local resistance rates (>20%) for empiric therapy 1, 5
• Inadequate treatment duration for pyelonephritis (should be 7-14 days depending on antibiotic choice) 1
• Treating asymptomatic bacteriuria in women with recurrent UTIs, as it fosters antimicrobial resistance and increases recurrence episodes 1

Urinalysis as a Predictor of Causative Agent

• Positive urinalysis results (positive leukocyte esterase, positive nitrites, elevated WBC count) are more likely associated with E. coli infections 7
• Negative urinalysis results with strong suspicion of UTI may suggest non-E. coli organisms, which could influence empiric antibiotic selection 7