From the Guidelines
Treatment of Group B strep (Streptococcus agalactiae) infections primarily involves antibiotics, with penicillin or ceftriaxone being the first-line therapy, and gentamicin may be added for certain cases. The choice of antibiotic and duration of treatment depend on the severity and type of infection, as well as patient factors such as penicillin allergy. For example, in cases of endocarditis due to group B streptococci, antibiotic treatment is similar to that of oral streptococci, except that short-term therapy is not recommended, and gentamicin should be given for 2 weeks 1.
Some key considerations for treatment include:
- The use of penicillin or ceftriaxone as the primary antibiotic, with gentamicin added in certain cases, such as endocarditis
- The importance of treating for an adequate duration, which can vary from 10-14 days for bacteremia to 2-3 weeks for endocarditis
- The need for alternative antibiotics, such as vancomycin or clindamycin, in patients with penicillin allergy
- The critical role of prompt treatment in preventing morbidity and mortality, especially in invasive infections
In terms of specific treatment regimens, penicillin or ceftriaxone, often in combination with gentamicin, are commonly used, with the specific dosing and duration depending on the clinical context and patient factors, as outlined in guidelines such as those from the European Society of Cardiology 1.
From the FDA Drug Label
Serious infections, such as pneumonia and endocarditis, due to susceptible strains of streptococci (including S pneumoniae) and meningococcus 150,000 - 300,000 units/kg/day divided in equal doses every 4 to 6 hours; duration depends on infecting organism and type of infection
Infections of the respiratory tract and soft tissues. Patients weighing 40 kg (88 lbs) or more: 250 mg to 500 mg every 6 hours.
Adults: Parenteral (IM or IV Administration): Serious infections due to aerobic gram-positive cocci and the more susceptible anaerobes (NOT generally including Bacteroides fragilis, Peptococcus species and Clostridium species other than Clostridium perfringens): 600 mg to 1,200 mg per day in 2,3 or 4 equal doses
Treatment Options for Group B Strep Infections:
- Penicillin G (IV): 150,000 - 300,000 units/kg/day divided in equal doses every 4 to 6 hours
- Ampicillin (IV): 250 mg to 500 mg every 6 hours for patients weighing 40 kg or more
- Clindamycin (IV): 600 mg to 1,200 mg per day in 2,3 or 4 equal doses for serious infections due to aerobic gram-positive cocci and susceptible anaerobes 2, 3, 4
From the Research
Treatment Options for Group B Strep Infections
The treatment options for group B strep (Streptococcus agalactiae) infections include:
- Intrapartum antibiotic prophylaxis for pregnant women who test positive for GBS and have one or more risk factors, with penicillin G being the preferred antibiotic 5, 6, 7
- Alternative antibiotics such as ampicillin, erythromycin, and clindamycin for women who are allergic to penicillin 5, 6, 7
- Vancomycin for women who are allergic to penicillin and have resistance to clindamycin and erythromycin 5, 8, 9
- Observation for at least 24 hours for asymptomatic neonates born to GBS-colonized mothers, with diagnostic work-up and initiation of ampicillin and gentamicin if signs of sepsis appear 5
- Aggressive treatment of the neonate with ampicillin and gentamicin for late-onset GBS infection 7
Antibiotic Resistance Patterns
GBS isolates have shown resistance to certain antibiotics, including:
- Erythromycin and clindamycin, with resistance rates increasing over time 8, 9
- Fluoroquinolones and aminoglycosides, with rising resistance rates 9
- Reduced susceptibility to beta-lactam antibiotics, including penicillin, in some countries 9
- Vancomycin resistance, with two documented cases 9
Prevention Strategies
Prevention strategies for group B strep infections include: