Does Staphylococcus epidermidis (S. epidermidis) in urine need to be treated during pregnancy?

Management of Staphylococcus epidermidis in Urine During Pregnancy

Staphylococcus epidermidis in urine during pregnancy does not typically require treatment unless there are symptoms of urinary tract infection or the patient is undergoing urologic procedures.

Understanding S. epidermidis in Urine During Pregnancy

Staphylococcus epidermidis is commonly considered a contaminant in urine cultures rather than a true pathogen. Unlike other organisms such as Group B Streptococcus (GBS), there are important distinctions to make:

• S. epidermidis primarily colonizes the skin and is a frequent contaminant in urine samples 1
• Studies show poor predictive value of S. epidermidis in voided urine specimens - when bladder puncture was performed to confirm true bacteriuria, none of the patients with S. epidermidis in voided specimens had bacteria in the aspirated urine 1
• This contrasts with true uropathogens like E. coli, where the same bacteria were found in the bladder in all cases 1

Evidence-Based Approach to Asymptomatic Bacteriuria in Pregnancy

The Infectious Diseases Society of America (IDSA) provides clear guidelines regarding asymptomatic bacteriuria (ASB) in pregnancy:

1. Screen and treat ASB in pregnancy (strong recommendation, moderate-quality evidence) 2
2. Treatment duration: 4-7 days of antimicrobial treatment is recommended rather than shorter courses 2

However, these recommendations apply specifically to true uropathogens, not contaminants:

• The IDSA guidelines focus on treating true bacteriuria that represents bladder colonization
• S. epidermidis is frequently a contaminant and rarely represents true bacteriuria 1
• A high proportion (33%) of women with apparent ASB may have Enterococcus species or other skin flora isolated, which would generally be considered contaminants 2

Algorithm for Management of S. epidermidis in Urine During Pregnancy

1. Determine if it's a true infection or contamination:

   • Was the sample properly collected? (mid-stream clean catch)
   • Is there a high colony count (≥105 CFU/ml)?
   • Are there symptoms of UTI?
   • Are there pyuria/leukocyte esterase/nitrites present?

2. If suspected contamination (most common with S. epidermidis):

   • Repeat urine culture with proper collection technique
   • If repeat culture is negative or shows different organisms, no treatment is needed

3. If confirmed true infection (rare with S. epidermidis):

   • Treat according to IDSA guidelines with 4-7 days of appropriate antibiotics 2
   • Follow up with a test of cure after completion of therapy

Special Considerations

• Urologic procedures: If the pregnant woman is undergoing urologic procedures, antimicrobial prophylaxis may be warranted regardless of the organism 2
• Symptoms: If the patient has symptoms of UTI, treatment should be initiated regardless of the organism isolated 2

Common Pitfalls to Avoid

1. Overtreatment: Treating contaminants like S. epidermidis can lead to unnecessary antibiotic exposure, potential side effects, and antimicrobial resistance 3

2. Misdiagnosis: Assuming all bacteria in urine represent true infection rather than contamination 1

3. Inadequate follow-up: If treatment is initiated, failure to confirm clearance of bacteriuria 3

4. Antimicrobial resistance: Rising prevalence of antimicrobial resistance in urinary tract infections during pregnancy is concerning, including methicillin resistance in Staphylococci 4

In conclusion, while asymptomatic bacteriuria with true uropathogens requires treatment in pregnancy, S. epidermidis in urine is most commonly a contaminant and does not typically warrant antimicrobial therapy unless there are symptoms of infection or the patient is undergoing urologic procedures.