What is the recommended treatment for Enterococcus (a type of bacteria) urinary tract infection (UTI)?

Treatment of Enterococcus Urinary Tract Infections

For Enterococcus urinary tract infections, ampicillin (1-2g IV q6h) or amoxicillin (500mg PO q8h) is the preferred treatment for susceptible strains, while nitrofurantoin (100mg PO twice daily for 5 days) and fosfomycin (3g single dose) are excellent oral options for uncomplicated cystitis caused by vancomycin-resistant enterococci (VRE). 1

Treatment Algorithm for Enterococcus UTIs

Step 1: Confirm Diagnosis

• Obtain urine culture before initiating therapy
• Differentiate between asymptomatic bacteriuria (which should not be treated) and symptomatic infection

Step 2: Select Appropriate Treatment Based on Susceptibility

For Ampicillin-Susceptible Enterococci:

• Uncomplicated cystitis:

  • Amoxicillin 500mg PO q8h for 3-5 days 1
  • Alternative: Nitrofurantoin 100mg PO twice daily for 5 days (if CrCl >60 mL/min) 1
  • Alternative: Fosfomycin 3g single dose 1

• Complicated UTI or pyelonephritis:

  • Ampicillin 1-2g IV q6h for 7-14 days 1
  • Step down to oral amoxicillin when clinically improved 1

For Vancomycin-Resistant Enterococci (VRE):

• Uncomplicated cystitis:

  • Nitrofurantoin 100mg PO twice daily for 5 days (if CrCl >60 mL/min) 1
  • Alternative: Fosfomycin 3g single dose 1

• Complicated UTI or pyelonephritis:

  • Linezolid 600mg PO/IV q12h (63% cure rate for VRE urinary infections) 1, 2
  • Alternative: Daptomycin (for upper/bacteremic UTIs) 3, 4

Step 3: Treatment Duration

• Uncomplicated cystitis: 3-5 days 1
• Complicated UTI or pyelonephritis: 7-14 days 1

Special Considerations

Catheter-Associated UTIs

• Remove indwelling catheters when possible to aid in clearance 1, 4
• Asymptomatic bacteriuria with enterococci should not be treated 1

Assessment of Response

• Assess clinical response within 48-72 hours 1
• If symptoms persist or recur within 2 weeks, repeat urine culture and select a different antibiotic class 1

High-Level Aminoglycoside Resistance

• For serious infections with high-level aminoglycoside resistance, ampicillin, penicillin, or vancomycin alone may be used 5
• Combination therapy with aminoglycosides is only effective if the strain does not demonstrate high-level aminoglycoside resistance 5, 6

Prevention of Recurrent UTIs

For patients with recurrent enterococcal UTIs (≥3 UTIs per year or ≥2 UTIs in the last 6 months):

• Non-antimicrobial approaches:

  • Increased fluid intake (premenopausal women)
  • Vaginal estrogen replacement (postmenopausal women)
  • Methenamine hippurate
  • Consider probiotics, cranberry products, D-mannose 1

• Antimicrobial prophylaxis:

  • Consider when non-antimicrobial interventions have failed
  • Options include continuous or post-coital prophylaxis 1

Common Pitfalls to Avoid

1. Treating asymptomatic bacteriuria: Enterococcal colonization of the urinary tract without symptoms should not be treated 1, 3

2. Overuse of broad-spectrum antibiotics: Tailor therapy based on susceptibility results to minimize resistance 1

3. Failure to remove urinary catheters: Indwelling catheters should be removed when possible to aid in clearance 1, 4

4. Inadequate treatment duration: Ensure appropriate duration based on infection severity (3-5 days for uncomplicated cystitis, 7-14 days for complicated UTI/pyelonephritis) 1

5. Not recognizing VRE: Vancomycin-resistant enterococci require specific treatment approaches with limited options 1, 2, 3

6. Inappropriate use of linezolid: Reserve linezolid for more serious VRE infections rather than uncomplicated cystitis 1, 2