Treatment of Staphylococcus epidermidis Urinary Tract Infection
For Staphylococcus epidermidis UTI, obtain urine culture to confirm true infection (≥50,000 CFUs/mL in pure growth), then treat with vancomycin for methicillin-resistant strains or penicillinase-resistant penicillins for susceptible strains, with treatment duration of 7-14 days depending on symptom resolution. 1
Diagnosis Confirmation
Before initiating treatment, it's crucial to distinguish between colonization and true infection:
- Obtain a urine specimen for culture prior to starting antimicrobial therapy
- A pure growth of ≥50,000 CFUs/mL of S. epidermidis suggests true infection rather than contamination 1
- Consider patient symptoms and risk factors (indwelling catheters, nephrolithiasis, recent instrumentation) 2, 3
Risk Factors for S. epidermidis UTI
S. epidermidis is not a common uropathogen but can cause UTIs in specific situations:
- Indwelling urinary catheters or other devices 4, 5
- Recent urinary tract instrumentation 3
- Nephrolithiasis 2
- Immunocompromised status 4
- Anatomical abnormalities (especially in children) 3
Treatment Approach
First-line Treatment Options
For methicillin-resistant S. epidermidis (common in nosocomial infections):
- Vancomycin is the drug of choice 4
- Consider combination therapy with rifampin or gentamicin for serious infections 4
For methicillin-susceptible S. epidermidis:
- Penicillinase-resistant penicillins
- Cephalosporins (if susceptible) 4
Alternative Options (based on susceptibility testing)
- Doxycycline (69% of isolates susceptible in prosthetic joint infections) 6
- Linezolid (high susceptibility rates) 6
- Nitrofurantoin 100mg twice daily for uncomplicated cases 1
- Trimethoprim-sulfamethoxazole 160/800mg twice daily if susceptible 1
Treatment Duration
- 7 days for patients with prompt resolution of symptoms 1
- 10-14 days for those with delayed response 1
- For complicated UTIs (presence of risk factors, bacteremia), extend treatment to 10-14 days 1
Catheter Management
If a urinary catheter is present:
- If the catheter has been in place for ≥2 weeks, replace it to hasten symptom resolution 1
- Obtain urine culture specimens from freshly placed catheters 1
- Remove the catheter completely as soon as possible if no longer needed 1
Monitoring and Follow-up
- Monitor clinical response within 72 hours of initiating therapy 1
- Consider extending treatment duration, performing urologic evaluation, or adjusting antimicrobial regimen if no improvement occurs 1
- For patients with bacteremia, follow blood cultures to confirm clearance 2, 5
Special Considerations
- S. epidermidis can cause serious infections including bacteremia and septic shock, especially in debilitated patients 5
- Methicillin resistance is common in nosocomial S. epidermidis infections 4
- Standard susceptibility testing methods may not reliably detect methicillin resistance in S. epidermidis 4
- In patients with nephrolithiasis and S. epidermidis UTI, consider ureteral stenting in addition to antibiotic therapy 2
Common Pitfalls
- Dismissing S. epidermidis as a contaminant without considering clinical context 3
- Failing to use reliable methods for detecting methicillin resistance 4
- Not removing or replacing indwelling catheters when treating the infection 1
- Inadequate treatment duration for complicated infections 1
- Not considering underlying anatomical abnormalities, especially in children 3