What is the recommended treatment for a patient with a urine analysis (UA) culture positive for Group B streptococcus (GBS) who is currently being treated with Augmentin (amoxicillin-clavulanate)?

Treatment of Group B Streptococcus in Urine Culture

Augmentin (amoxicillin-clavulanate) is an appropriate treatment choice for Group B streptococcus (GBS) bacteriuria, and should be continued as the current treatment.

Understanding GBS Bacteriuria

GBS in urine is a significant finding that requires proper management:

• GBS bacteriuria at any concentration during pregnancy is a marker for heavy genital tract colonization and increases risk for early-onset GBS disease in newborns 1
• Even in non-pregnant adults, GBS is a significant urinary pathogen, with urinary tract abnormalities (60%) and chronic renal failure (27%) being common underlying conditions 2
• GBS accounts for approximately 2% of positive urine cultures in non-pregnant adults 2

Treatment Recommendations

First-line Treatment Options:

• Amoxicillin-clavulanate (Augmentin) is a recommended first-line oral treatment option for GBS bacteriuria 1
• Augmentin is particularly effective because:
  • The clavulanic acid component reduces resistance in most Gram-negative urinary pathogens 3
  • Clinical trials have shown approximately 70% success rates even for amoxicillin-resistant organisms 3
  • GBS isolates have demonstrated high susceptibility to Augmentin 4

Dosing Considerations:

• For urinary tract infections, the FDA-approved dosing options include:
  • 875 mg/125 mg every 12 hours
  • 500 mg/125 mg every 8 hours
  • Both regimens show comparable efficacy, though the twice-daily regimen may have fewer severe diarrhea cases (1% vs 2%) 5

Special Considerations

For Pregnant Patients:

• If the patient is pregnant, additional management is required beyond the antibiotic treatment:
  • Women with GBS bacteriuria during any trimester of pregnancy should receive intrapartum antibiotic prophylaxis (IAP) during labor, regardless of subsequent negative cultures 1
  • Treating GBS colonization with oral antibiotics in pregnancy does not eliminate GBS from the genitourinary tract, and recolonization after treatment is common 1

For Non-pregnant Patients:

• Consider screening for underlying urinary tract abnormalities, as they are present in approximately 60% of non-pregnant adults with GBS UTI 2
• All GBS isolates should be tested for antibiotic susceptibility, especially in penicillin-allergic patients 1

Monitoring and Follow-up

• Monitor for common side effects of Augmentin, particularly diarrhea, which occurs in approximately 14-15% of patients 5
• Consider follow-up urine culture after completion of treatment to confirm eradication, especially in patients with risk factors for complications
• Be aware that oral antibiotics can cause temporary negative cultures in GBS-colonized patients, which may not represent true eradication 6

Alternative Antibiotics

If the patient has a penicillin allergy or Augmentin intolerance:

• Clindamycin can be used if susceptibility testing confirms sensitivity, but be aware that GBS has 14-26.6% resistance rates to clindamycin 1
• Nitrofurantoin and sulfamethoxazole-trimethoprim are also recommended by WHO as first-choice options for GBS urinary tract infections 1

Pitfalls to Avoid

• Don't rely on pyuria alone: A negative test for pyuria is not a reliable indicator of the absence of GBS bacteriuria 4
• Don't assume eradication after treatment: Oral antibiotics can cause temporary negative cultures in GBS-colonized patients 6
• Don't miss underlying conditions: GBS bacteriuria often signals underlying urinary tract abnormalities that should be evaluated 2