Treatment of Enterococcus faecalis in Urine with Colony Count of 10,000 to 49,000
Asymptomatic bacteriuria with Enterococcus faecalis in the range of 10,000 to 49,000 CFU/mL should not be treated with antibiotics unless the patient belongs to a specific high-risk group. This recommendation is based on current guidelines that emphasize avoiding unnecessary antibiotic use for asymptomatic bacteriuria.
Determining Whether Treatment is Necessary
Do Not Treat:
- Asymptomatic bacteriuria in most patients
- Patients with indwelling catheters without symptoms
- Elderly patients without symptoms
- Low colony counts (10,000-49,000 CFU/mL) in asymptomatic patients
Consider Treatment Only If:
- Symptomatic UTI (dysuria, frequency, urgency, suprapubic pain)
- Pregnant women
- Patients undergoing urologic procedures
- Recent renal transplant recipients (within 1 month of transplant) 1
- Neutropenic patients
Rationale for Non-Treatment
The Infectious Diseases Society of America (IDSA) guidelines for asymptomatic bacteriuria strongly recommend against treating asymptomatic bacteriuria in most patient populations 1. This recommendation is particularly relevant for Enterococcus faecalis at relatively low colony counts (10,000-49,000 CFU/mL), which often represents colonization rather than true infection.
Studies have shown that:
- Treatment of asymptomatic bacteriuria does not prevent symptomatic UTIs
- Unnecessary treatment contributes to antimicrobial resistance
- In renal transplant recipients >1 month post-surgery, treatment of asymptomatic bacteriuria does not prevent pyelonephritis or improve graft function 1
When Treatment is Indicated
If the patient is symptomatic or belongs to a high-risk group where treatment is indicated, the following options are recommended:
First-line options:
- Nitrofurantoin (100 mg twice daily for 5 days) - shows excellent efficacy against E. faecalis with minimal resistance patterns 2, 3
- Fosfomycin (single 3g dose) - FDA approved for UTI caused by E. faecalis 1
Alternative options:
- Ampicillin (500 mg orally every 8 hours) - if susceptible 1
- Amoxicillin-clavulanate (500/125 mg orally every 8 hours)
For resistant strains:
- Linezolid - for vancomycin-resistant E. faecalis 1, 4
- Daptomycin - active against E. faecalis, including vancomycin-resistant isolates 2
Important Considerations
Differentiate colonization from infection: E. faecalis in urine with colony counts of 10,000-49,000 CFU/mL without symptoms often represents colonization rather than infection 1.
Susceptibility testing: When treatment is necessary, obtain susceptibility testing as E. faecalis can have variable resistance patterns 2.
Catheter management: If the patient has an indwelling catheter, consider catheter removal or replacement rather than antimicrobial treatment for asymptomatic bacteriuria 2.
Avoid unnecessary treatment: Routine treatment of asymptomatic bacteriuria with E. faecalis contributes to antimicrobial resistance and provides no clinical benefit in most patient populations 1.
Check for urological abnormalities: E. faecalis UTIs are associated with higher rates of anatomical abnormalities of the urinary tract 5, so consider imaging studies if clinically indicated.
By following these evidence-based recommendations, clinicians can ensure appropriate management of E. faecalis in urine specimens while minimizing unnecessary antibiotic use and reducing the risk of antimicrobial resistance.