What is the 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

First-Line Options:

• Nitrofurantoin 100mg twice daily for 5 days 1, 2
• Fosfomycin tromethamine 3g single dose 1, 2
• Trimethoprim-sulfamethoxazole 160/800mg twice daily for 3 days (only if local E. coli resistance is <20% and no use of this antibiotic in previous 3-6 months) 1, 3

Second-Line Options:

• Fluoroquinolones (e.g., ciprofloxacin) - should be reserved for situations where first-line agents cannot be used due to increasing resistance and risk of adverse effects 1, 4
• Oral cephalosporins (e.g., cephalexin, cefixime) 2
• Amoxicillin-clavulanate 2

Treatment for Complicated UTIs/Pyelonephritis

Oral Treatment Options:

• Ciprofloxacin 500mg twice daily for 7 days (if local resistance <10%) 1, 4
• Trimethoprim-sulfamethoxazole 160/800mg twice daily for 14 days (only if susceptibility confirmed) 1
• If using oral β-lactams, start with an initial IV dose of ceftriaxone 1g 1

Parenteral Treatment for Hospitalized Patients:

• Initial IV therapy options include: 1
  • Fluoroquinolones
  • Aminoglycosides (with/without ampicillin)
  • Extended-spectrum cephalosporins
  • Carbapenems

Treatment for Pediatric UTIs

• For febrile infants with UTI, parenteral options include: 5

  • Ceftriaxone 75 mg/kg every 24h
  • Cefotaxime 150 mg/kg per day divided every 6-8h
  • Gentamicin 7.5 mg/kg per day divided every 8h

• Oral options for pediatric UTIs include: 5

  • Amoxicillin-clavulanate 20-40 mg/kg per day in 3 doses
  • Cefixime 8 mg/kg per day in 1 dose
  • Cephalexin 50-100 mg/kg per day in 4 doses

• Total course of therapy for pediatric UTIs should be 7-14 days 5

Special Considerations

For Multidrug-Resistant (MDR) E. coli:

• For ESBL-producing E. coli: nitrofurantoin, fosfomycin, or pivmecillinam for uncomplicated UTIs 2
• For carbapenem-resistant E. coli (CRE): 5
  • Ceftazidime-avibactam 2.5g IV q8h (for complicated UTIs)
  • Meropenem-vaborbactam 4g IV q8h or imipenem-cilastatin-relebactam 1.25g IV q6h
  • Single-dose aminoglycoside for simple cystitis due to CRE

For Recurrent UTIs:

• Biofilm formation capacity may be an important factor in recurrent UTIs 6
• E. coli strains belonging to phylogenetic group B2 are associated with higher rates of persistence and relapse 6
• Consider longer treatment duration (7 days vs. 3 days) for infections with E. coli strains from phylogenetic group B2 6

Common Pitfalls to Avoid

• Using fluoroquinolones as first-line therapy for uncomplicated UTIs due to increasing resistance and risk of adverse effects 1, 2
• Using antibiotics with known high local resistance rates (>20%) for empiric therapy 1
• Using nitrofurantoin for treatment of pyelonephritis or febrile UTIs in infants, as it does not achieve therapeutic concentrations in the bloodstream 5
• Inadequate treatment duration for pyelonephritis (should be 7-14 days depending on antibiotic choice) 1
• Failing to obtain pre-treatment urine culture in patients with recurrent UTIs 1
• Not considering local resistance patterns when selecting empiric therapy 2, 7

Monitoring and Follow-up

• Tailor therapy based on culture and susceptibility results when available 1
• For pediatric patients with febrile UTIs, renal and bladder ultrasonography should be considered to detect anatomic abnormalities 5
• For recurrent UTIs, evaluate for underlying structural or functional abnormalities 1
• Monitor for increasing resistance patterns, as over 50% of E. coli isolates in some communities show resistance to beta-lactams and quinolones 7