What is the recommended treatment for Group B Streptococcus (GBS) urinary tract infection (UTI)?

Treatment of Group B Streptococcus (GBS) Urinary Tract Infection

Penicillin-based antibiotics are the first-line treatment for Group B Streptococcus urinary tract infections, with oral penicillin V (500 mg four times daily for 10 days) or amoxicillin (500 mg three times daily for 10 days) recommended as the primary options for non-pregnant adults. 1

First-Line Treatment Options

For non-pregnant adults with GBS UTI, the recommended treatment options include:

• First choice options:

  • Oral penicillin V: 500 mg four times daily for 10 days
  • Amoxicillin: 500 mg three times daily for 10 days 1

• Alternative first-line options:

  • Amoxicillin-clavulanic acid
  • Nitrofurantoin
  • Sulfamethoxazole-trimethoprim 1

Treatment for Penicillin Allergy

For patients with penicillin allergy, alternative options include:

• Cefazolin (if no history of anaphylaxis to penicillin)
• Clindamycin: 300 mg four times daily for 10 days
• Vancomycin (for severe allergies) 1

Special Considerations

Antibiotic Resistance

Recent evidence shows concerning resistance patterns that must be considered when selecting treatment:

• Penicillin resistance: up to 18.3%
• Ampicillin resistance: up to 81.6% (particularly concerning)
• Clindamycin resistance: up to 26.6% 2

These resistance patterns highlight the importance of obtaining culture and sensitivity testing when possible to guide therapy, especially in cases of treatment failure.

Pregnancy

GBS UTI during pregnancy requires special attention:

• Treat the acute infection as in non-pregnant adults
• Document GBS bacteriuria in the patient's record
• Provide intrapartum antibiotic prophylaxis (IAP) during labor regardless of whether treatment was previously given 1, 3

Recommended IAP regimens:

• Penicillin G: 5 million units IV initial dose, then 2.5-3.0 million units IV every 4 hours until delivery
• Ampicillin: 2 g IV initial dose, then 1 g IV every 4 hours until delivery
• Cefazolin (for penicillin allergy): 2 g IV initial dose, then 1 g IV every 8 hours until delivery 1

Treatment Algorithm

1. Confirm diagnosis with urine culture showing GBS
2. Assess for penicillin allergy:
   • If no allergy: Use penicillin V or amoxicillin
   • If mild allergy (no anaphylaxis): Consider cefazolin
   • If severe allergy: Use clindamycin or vancomycin
3. Consider local resistance patterns when selecting therapy
4. Treat for 10 days
5. Obtain follow-up urine culture 7 days after completing therapy to confirm clearance
6. For pregnant women: Document GBS bacteriuria and plan for IAP during labor

Pitfalls and Caveats

• Don't ignore GBS bacteriuria in pregnancy: Even asymptomatic bacteriuria with GBS requires treatment and subsequent IAP during labor 3
• Avoid fluoroquinolones for uncomplicated cases: Reserve these for pyelonephritis or severe cases 1
• Don't use carbapenems unless multidrug resistance is confirmed 1
• Be aware of increasing resistance: The high ampicillin resistance rate (81.6%) reported in some regions is concerning and may necessitate alternative therapy 2
• Remove infected catheters if present, as they can serve as a reservoir for infection 1