What is the treatment approach for a Staphylococcus (Staph) epidermidis urinary tract infection (UTI)?

Treatment of Staphylococcus epidermidis Urinary Tract Infection

For Staphylococcus epidermidis UTI, treatment should include catheter removal if present, urine culture before starting antibiotics, and antimicrobial therapy with vancomycin for methicillin-resistant strains or penicillinase-resistant penicillins for susceptible strains for 7-14 days depending on symptom resolution.

Diagnosis Considerations

• Obtain urine specimen for culture prior to initiating antimicrobial therapy due to the wide spectrum of potential infecting organisms and increased likelihood of antimicrobial resistance 1
• S. epidermidis is often considered a contaminant, but can be a true pathogen in specific circumstances:
  • Patients with indwelling catheters or urinary devices 2
  • Patients with nephrolithiasis 3
  • Immunocompromised patients 2
  • Children with anatomic variants 4
• Differentiate between contamination and true infection:
  • Pure growth of ≥50,000 CFUs/mL of S. epidermidis suggests true infection 1, 5
  • Presence of pyuria or bacteriuria on urinalysis supports infection diagnosis 5

Catheter Management

• If an indwelling catheter has been in place for ≥2 weeks at the onset of UTI and is still indicated, replace the catheter to hasten symptom resolution and reduce risk of subsequent bacteriuria and UTI 1
• Obtain urine culture specimens from freshly placed catheters prior to initiating antimicrobial therapy 1
• If catheter is no longer needed, remove it completely 1

Antimicrobial Therapy

First-line options:

1. For methicillin-resistant S. epidermidis (MRSE):

   • Vancomycin is the drug of choice 2
   • Consider combination therapy with rifampin for serious infections 2

2. For methicillin-susceptible S. epidermidis:

   • Penicillinase-resistant penicillins (e.g., nafcillin, oxacillin) 2
   • Cephalosporins (if susceptible) 2

Duration of therapy:

• 7 days for patients with prompt resolution of symptoms 1
• 10-14 days for those with delayed response 1
• This recommendation applies regardless of whether the patient remains catheterized or not 1

Special Considerations

• S. epidermidis isolates from nosocomial infections frequently show methicillin resistance 2
• Cross-resistance between methicillin and cephalosporins can occur 2
• Susceptibility testing is crucial as S. epidermidis may appear susceptible to methicillin unless reliable testing methods are used 2
• For serious infections with methicillin-resistant strains, consider combination therapy with vancomycin plus rifampin or gentamicin 2

Monitoring and Follow-up

• Monitor clinical response within 72 hours of initiating therapy 1
• If no improvement occurs within 72 hours, consider:
  • Extending treatment duration
  • Performing urologic evaluation 1
  • Adjusting antimicrobial regimen based on culture and susceptibility results 1

Prevention Strategies

• Discontinue urinary catheters as soon as possible 1
• For patients with recurrent UTIs, consider preventive measures:
  • Increased fluid intake
  • Avoiding prolonged urine retention 5
  • For patients with nephrolithiasis, consider urologic evaluation 3

S. epidermidis UTI is uncommon but should be treated appropriately when confirmed by proper urine culture techniques, especially in patients with risk factors such as indwelling catheters or nephrolithiasis.