What is the recommended treatment for a patient with a urinary tract infection (UTI) caused by Enterococcus faecalis?

Treatment for UTI Caused by Enterococcus faecalis

Nitrofurantoin 100mg twice daily for 5 days is the recommended first-line treatment for uncomplicated UTI caused by Enterococcus faecalis. 1

Treatment Selection Based on Susceptibility Testing

The urinalysis and culture results show:

• Positive leukocyte esterase (1+)
• Trace protein
• Trace ketones
• Enterococcus faecalis (25,000-50,000 CFU/mL)
• Susceptibility testing shows the organism is susceptible to ciprofloxacin, levofloxacin, nitrofurantoin, penicillin, and vancomycin, but resistant to tetracycline

First-line Treatment Options:

1. Nitrofurantoin 100mg twice daily for 5 days

   • Recommended by the American Urological Association as first-line therapy for uncomplicated UTIs 1
   • Excellent activity against Enterococcus faecalis, including vancomycin-resistant strains 2
   • 88% of enterococci are susceptible to nitrofurantoin in clinical studies 3
   • Contraindicated if CrCl <60 mL/min 1

2. Fosfomycin 3g single dose

   • Alternative if compliance is a concern 1
   • Preferred in patients with renal impairment (CrCl <60 mL/min) 1
   • Slightly lower efficacy than other options (77% clinical success) 1

3. Penicillin/Ampicillin

   • The susceptibility report indicates the organism is susceptible to penicillin
   • "Enterococci susceptible to penicillin are predictably susceptible to ampicillin, amoxicillin, ampicillin-sulbactam, amoxicillin-clavulanate, and piperacillin-tazobactam" (per lab report)

Treatment Considerations

Avoid These Options:

• Fluoroquinolones (ciprofloxacin, levofloxacin): Despite susceptibility, these should be reserved for more serious infections due to:

  • FDA warnings about serious adverse effects affecting tendons, muscles, joints, nerves, and central nervous system 1
  • CDC recommendation to avoid fluoroquinolones for uncomplicated UTIs 1

• Tetracycline: The organism is resistant to tetracycline (per lab report)

• Cephalosporins, trimethoprim-sulfamethoxazole, and clindamycin: "For Enterococcus species, aminoglycosides (except for high-level resistance screening), cephalosporins, clindamycin, and trimethoprim-sulfamethoxazole are not effective clinically" (per lab report)

Special Considerations:

• If the patient has renal impairment (CrCl <60 mL/min), avoid nitrofurantoin and use fosfomycin 3g single dose instead 1
• If the patient is pregnant at term (38-42 weeks) or has G6PD deficiency, nitrofurantoin is contraindicated 1

Follow-up Recommendations

• If symptoms persist after treatment, obtain a follow-up urine culture 1-2 weeks after completing therapy 1
• If bacteriuria recurs, select an alternative agent rather than repeating the same antibiotic 1
• Consider urological evaluation if there are recurrent infections, as enterococcal UTIs are associated with higher rates of anatomical abnormalities 4

Potential Complications

• Enterococcal UTIs are associated with higher rates of urinary tract abnormalities and worse prognosis in terms of renal scarring and recurrences 4
• The presence of kidney stones (as seen in some patients with enterococcal UTIs) may require additional urological intervention 5

Treatment Duration

• For uncomplicated lower UTI: 5 days of therapy is sufficient 1
• For complicated UTI: 7-14 days of therapy is recommended 1
• For pyelonephritis or upper UTI: 10-14 days of therapy is recommended 1