Treatment Options for Group B Streptococcus UTI in Patients with Penicillin and Bactrim Allergies and Clindamycin Resistance
For patients with Group B Streptococcus (GBS) urinary tract infection who are allergic to penicillin and Bactrim (trimethoprim/sulfamethoxazole) and have clindamycin-resistant isolates, vancomycin is the recommended treatment option. 1, 2
Treatment Algorithm Based on Allergy Severity
Assessment of Penicillin Allergy:
- Determine if the penicillin allergy involves history of anaphylaxis, angioedema, respiratory distress, or urticaria (severe allergy) 1, 2
- For patients without severe reactions, cefazolin could be considered if cross-reactivity risk is deemed acceptable 1
First-Line Treatment for Severe Penicillin Allergy with Clindamycin Resistance:
- Vancomycin 1g IV every 12 hours is the recommended treatment when clindamycin resistance is confirmed 1, 2
- This recommendation is particularly important since the patient also has Bactrim allergy, further limiting treatment options 2
Antimicrobial Resistance Considerations
- GBS isolates have shown increasing resistance to clindamycin and erythromycin in recent years, making susceptibility testing crucial 1, 3
- While all GBS isolates remain susceptible to penicillin worldwide, this is not an option for penicillin-allergic patients 2
- Studies have shown high-level resistance to erythromycin and clindamycin among GBS isolates, highlighting the importance of alternative treatments 4
Important Clinical Considerations
- GBS in urine at concentrations of ≥10⁴ colony-forming units/ml should be reported and treated 1
- For non-pregnant adults with GBS UTI, treatment duration should follow standard UTI guidelines (typically 7 days for men, 5 days for women with uncomplicated infection) 5
- Consider consultation with an infectious disease specialist for complicated cases or when limited treatment options are available 2
Pitfalls and Caveats
- Avoid cephalosporins in patients with severe penicillin allergy due to risk of cross-reactivity (approximately 10% of patients with penicillin allergy) 2
- Do not use erythromycin as it is no longer recommended for GBS infections due to increasing resistance 2, 3
- Resistance to clindamycin has been increasing over time, with studies showing resistance rates of 21% or higher 3
- Always obtain susceptibility testing when treating GBS infections in patients with multiple antibiotic allergies to guide appropriate therapy 1, 2