From the Guidelines
Penicillin G is the recommended antibiotic for treating Streptococcus agalactiae (Group B strep) urinary tract infections (UTIs), given its narrow spectrum of activity and the fact that Group B strep remains universally susceptible to penicillins 1.
Treatment Options
- For women with symptomatic or asymptomatic GBS urinary tract infection detected during pregnancy, treatment should be according to current standards of care for urinary tract infection during pregnancy 1.
- Penicillin G, 5 million units intravenously initial dose, then 2.5 million units intravenously every 4 hours until delivery, is the preferred regimen for women without penicillin allergy 1.
- Alternative regimens include ampicillin, 2 g intravenously initial dose, then 1 g intravenously every 4 hours until delivery 1.
Considerations for Penicillin-Allergic Patients
- For penicillin-allergic women, cefazolin, 2 g intravenously initial dose, then 1 g intravenously every 8 hours until delivery, can be used for those not at high risk for anaphylaxis 1.
- Clindamycin and erythromycin susceptibility testing should be performed on isolates obtained during GBS prenatal carriage screening for women at high risk for anaphylaxis 1.
- Vancomycin, 1 g intravenously every 12 hours until delivery, can be used for women with immediate penicillin hypersensitivity if susceptibility testing is not possible or isolates are resistant to erythromycin or clindamycin 1.
Key Points
- Group B strep remains universally susceptible to penicillins because it has not developed beta-lactamase production.
- Treatment duration typically ranges from 5-7 days for uncomplicated UTIs to 10-14 days for complicated infections or pyelonephritis.
- Adequate hydration and follow-up urine cultures after treatment completion are recommended to ensure eradication of the infection.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Penicillin G Sodium for injection, USP may be given intravenously or intramuscularly. The usual dose recommendations are as follows: Adult Patients Clinical IndicationDosage Serious infections due to susceptible strains of streptococci (including S pneumoniae) and staphylococci-septicemia, empyema, pneumonia, pericarditis, endocarditis and meningitis 5 to 24 million units/day depending on the infection and its severity administered in equally divided doses every 4 to 6 hours
- Penicillin can be used to treat streptococcal infections, including those caused by Streptococcus agalactiae.
- The recommended dosage for serious infections due to susceptible strains of streptococci is 5 to 24 million units/day, depending on the infection and its severity.
- Ampicillin may also be effective against Streptococcus agalactiae, but the provided drug label does not specifically mention its use for this indication.
- It is essential to note that the treatment of Streptococcus agalactiae UTIs may require a different approach, and the provided information may not be directly applicable. 2
From the Research
Antibiotic Treatment for Streptococcus agalactiae UTIs
The following antibiotics can be considered for the treatment of Streptococcus agalactiae (Group B strep) urinary tract infections (UTIs):
- Ampicillin: High susceptibility rates have been reported, making it a potential first-line treatment option 3, 4
- Penicillin: Also shows high susceptibility rates, supporting its use as a first-line antibiotic 5, 4
- Cefazolin: Demonstrated susceptibility in some studies, making it another potential treatment option 4
- Clindamycin: May be considered for patients allergic to beta-lactam agents, although resistance rates vary 5, 4
- Erythromycin: Has been used in the past, but high resistance rates have been reported, making it a less favorable option 5, 4
- Vancomycin: Can be administered in cases where patients are allergic to penicillin and second-line antibiotics are ineffective 6
Important Considerations
- The increasing resistance rate to certain antibiotics, such as erythromycin and clindamycin, may lead to a new epidemiological situation 5
- A thorough examination and identification of infection foci, including those outside the urinary system, are crucial for successful treatment 3
- The choice of antibiotic should be based on individual patient needs and susceptibility patterns 3, 4