What is the treatment for a urinary tract infection caused by Staphylococcus epidermidis in urine?

Treatment of Staphylococcus epidermidis in Urine

Staphylococcus epidermidis isolated from urine should NOT be routinely treated in most clinical scenarios, as it typically represents either contamination or asymptomatic bacteriuria that does not warrant antimicrobial therapy. 1

Key Clinical Decision Points

When NOT to Treat (Most Common Scenario)

Asymptomatic bacteriuria with S. epidermidis should not be treated, even when isolated from properly collected urine specimens 1. The evidence is clear:

• Coagulase-negative staphylococci (including S. epidermidis) are explicitly listed as organisms that are "not considered clinically relevant urine isolates for otherwise healthy children" 1
• Treatment of asymptomatic bacteriuria increases antimicrobial resistance, costs, and adverse drug effects without improving outcomes 1
• Screening for and treating asymptomatic bacteriuria is harmful in most populations 1

When to Consider Treatment (Specific Exceptions)

Treatment should be considered ONLY in the following specific clinical scenarios:

1. Symptomatic UTI with Confirmed S. epidermidis

If the patient has:

• Fever, dysuria, flank pain, or other UTI symptoms AND
• Properly collected urine culture (catheterized or suprapubic) showing ≥50,000 CFU/mL of S. epidermidis as a single pathogen 1

Then treat with targeted antimicrobial therapy based on susceptibility testing 1, 2:

• Obtain urine culture BEFORE initiating therapy 1
• Duration: 7 days for prompt symptom resolution, 10-14 days for delayed response 1
• Ciprofloxacin is FDA-approved for UTIs caused by methicillin-susceptible S. epidermidis 2

2. Catheter-Associated UTI

For patients with indwelling urinary catheters:

• Replace the catheter if it has been in place ≥2 weeks before starting antimicrobial therapy 1
• Antibiotic therapy alone without catheter removal/replacement will likely fail due to biofilm formation 1
• If the catheter cannot be removed, expect treatment failure and relapse 1

3. Pre-Procedure Screening (Endoscopic Urologic Surgery)

Screen for and treat asymptomatic bacteriuria (including S. epidermidis) ONLY before endoscopic urologic procedures with mucosal trauma (e.g., TURP, ureteroscopy, lithotripsy) 1, 3:

• Obtain urine culture prior to procedure 1, 3
• Use short-course therapy: 1-2 doses of targeted antimicrobial 1
• Administer 30-60 minutes before the procedure 1, 3

4. High-Risk Populations Requiring Investigation

S. epidermidis causing true UTI (not contamination) suggests underlying pathology 4, 5, 6, 7:

• Children with urinary tract abnormalities (vesicoureteral reflux, anatomic variants) 4, 5, 7
• Patients with nephrolithiasis (kidney stones) 6
• Patients on continuous antibiotic prophylaxis 4
• Immunocompromised patients or those with indwelling devices 4, 6

If S. epidermidis is isolated with significant colony counts and symptoms in these populations, workup for underlying urinary tract abnormalities is indicated 5, 7.

Common Pitfalls to Avoid

• Do NOT dismiss S. epidermidis as contamination if the patient has symptoms AND properly collected urine (catheterized/suprapubic specimen) 4, 5, 7
• Do NOT treat asymptomatic bacteriuria in routine scenarios - this increases resistance and harms patients 1
• Do NOT use antimicrobials without removing/replacing long-term catheters - biofilm makes eradication impossible 1
• Do NOT use empiric therapy without culture - obtain cultures first to guide targeted therapy 1

Antimicrobial Selection When Treatment is Indicated

When treatment is necessary based on the criteria above:

• Base selection on local susceptibility patterns and adjust according to culture results 1
• Ciprofloxacin is FDA-approved for UTIs caused by methicillin-susceptible S. epidermidis 2
• Many S. epidermidis strains are methicillin-resistant, requiring susceptibility-guided therapy 4, 6
• Obtain susceptibility testing before finalizing antimicrobial choice 1