Treatment of Enterococcus Prostatitis
For Enterococcus prostatitis, use ampicillin as first-line therapy for susceptible strains, or fluoroquinolones (levofloxacin or ofloxacin) for empiric treatment, with treatment duration of 4-6 weeks for acute bacterial prostatitis and longer courses for chronic bacterial prostatitis.
Pathogen Context and Clinical Significance
Enterococcus species, particularly Enterococcus faecalis, are recognized causative organisms in bacterial prostatitis, though they account for fewer than 10% of confirmed bacterial prostatitis cases 1. Chronic bacterial prostatitis encompasses a broader spectrum of species beyond the typical Enterobacterales seen in acute cases 1.
Antimicrobial Selection Strategy
First-Line Therapy for Susceptible Strains
- Ampicillin is the preferred agent for ampicillin-susceptible E. faecalis 2
- Fluoroquinolones demonstrate excellent activity against Enterococcus in prostatitis, with resistance rates of only 4.8% for levofloxacin and 9.7% for ciprofloxacin in Korean isolates 3
- Levofloxacin 500 mg orally daily or ofloxacin 200 mg orally twice daily are appropriate fluoroquinolone options based on urethritis treatment paradigms that can be extrapolated to prostatitis 1
Alternative Regimens
- For ampicillin-resistant strains, vancomycin is the recommended alternative 2
- For both ampicillin and vancomycin-resistant enterococci, linezolid or daptomycin should be used based on susceptibility testing 2
- Nitrofurantoin combined with rifampin for 6 weeks has demonstrated efficacy in vancomycin-resistant E. faecium prostatitis, though this is based on limited case report data 4
Agents to Avoid
Do not use tetracycline, erythromycin, or trimethoprim/sulfamethoxazole empirically due to high resistance rates (97.5%, 95%, and 31.5% respectively) in Enterococcus isolates from chronic bacterial prostatitis 3. Despite historical use of these agents for chronic prostatitis, resistance patterns make them unsuitable for enterococcal infections 3.
Treatment Duration
- For acute bacterial prostatitis: 4-6 weeks of therapy 1
- For chronic bacterial prostatitis: extended therapy beyond 6 weeks is often required 5
- The duration depends on symptom resolution and microbiological clearance 1
Diagnostic Considerations
- Obtain midstream urine culture in acute bacterial prostatitis to identify the causative organism and guide antibiotic selection 6
- Use the Meares-Stamey 2- or 4-glass test for chronic bacterial prostatitis to confirm prostatic localization 6
- Critical pitfall: Never perform prostatic massage in acute bacterial prostatitis, as this can precipitate bacteremia 6
Special Clinical Scenarios
Combination Therapy for Resistant Strains
For aminoglycoside-resistant enterococcal strains, ampicillin 2 g IV every 4 hours plus ceftriaxone 2 g IV every 12 hours for 6 weeks is reasonable 1. This double β-lactam regimen avoids aminoglycoside nephrotoxicity while maintaining efficacy 1.
Prosthetic Material or Endocarditis Concerns
If enterococcal bacteremia persists >4 days or if there is concern for endovascular infection, perform transesophageal echocardiography to evaluate for endocarditis 2. Failure to identify endocarditis leads to inadequate treatment duration and increased mortality 2.
Key Clinical Pitfalls
- Inadequate treatment duration is a common error, particularly when endovascular infection is missed 2
- Fluoroquinolones remain suitable despite concerns about resistance, given the low resistance rates (4.8-9.7%) in enterococcal prostatitis isolates 3
- Empiric anti-enterococcal therapy should be considered in healthcare-associated infections, particularly in immunocompromised patients or those with valvular heart disease 2
- Anatomical limitations of the prostate make achieving therapeutic antibiotic concentrations challenging, necessitating prolonged therapy 5, 7