What is the recommended treatment for a patient with a urine culture positive for Group B Streptococcus (GBS), specifically beta-hemolytic streptococci?

From the Guidelines

The recommended treatment for a patient with a urine culture positive for Group B Streptococcus (GBS) is typically a course of antibiotics, with penicillin being the first-line treatment, as indicated by the most recent guidelines 1. For non-pregnant adults, amoxicillin 500 mg three times daily for 3-7 days is often prescribed. Alternatives for penicillin-allergic patients include cephalexin 500 mg four times daily, or clindamycin 300 mg four times daily for the same duration. For pregnant women, treatment is particularly important due to the risk of neonatal transmission, with penicillin G 5 million units IV initially, then 2.5 million units every 4 hours until delivery being the standard for intrapartum prophylaxis, as stated in the guidelines 1. GBS in urine requires treatment even in asymptomatic patients during pregnancy, as it indicates heavy colonization and increased risk of neonatal disease. Some key points to consider in the treatment of GBS include:

• The presence of GBS bacteriuria in any concentration in a pregnant woman is a marker for heavy genital tract colonization, and therefore, women with any quantity of GBS bacteriuria during pregnancy should receive intrapartum chemoprophylaxis 1.
• GBS can cause both symptomatic and asymptomatic urinary tract infections, which should be diagnosed and treated according to current standards of care for urinary tract infections in pregnancy 1.
• Women with GBS urinary tract infections during pregnancy should receive appropriate treatment at the time of diagnosis as well as intrapartum GBS prophylaxis 1.
• The American Academy of Pediatrics (AAP) updates guidelines for the management of at-risk infants, recommending early-onset GBS antibiotic prophylaxis, with penicillin G and ampicillin continuing to be recommended for intrapartum antibiotic prophylaxis 1.
• Cefazolin is recommended for women allergic to penicillin who are at low risk of anaphylaxis, while clindamycin should be administered to those colonized with GBS that is known to be susceptible to clindamycin, and vancomycin is recommended for women colonized with clindamycin-resistant GBS isolates who are allergic to penicillin and at high risk of anaphylaxis 1. Treatment is necessary because GBS can cause urinary tract infections, and in pregnant women, it can lead to chorioamnionitis, preterm labor, and serious neonatal infections. GBS remains highly susceptible to penicillins, which effectively eliminate the bacteria by inhibiting cell wall synthesis. It is essential to follow the most recent guidelines and consider the individual patient's circumstances, including pregnancy status and allergy history, when determining the best course of treatment for GBS.

From the Research

Treatment for Group B Streptococcus

The recommended treatment for a patient with a urine culture positive for Group B Streptococcus (GBS), specifically beta-hemolytic streptococci, is as follows:

• Penicillin is the drug of choice for GBS eradication 2
• Vancomycin could be the choice in the case of penicillin hypersensitivity 2, 3
• For patients with GBS bacteriuria, nitrofurantoin is recommended 3

Antibiotic Resistance Patterns

The antibiotic resistance patterns of GBS clinical isolates have been studied, and the results show:

• All isolates were sensitive to vancomycin, ofloxacin, ampicillin, ciprofloxacin, nitrofurantoin, and penicillin 3
• Some isolates exhibited intermediate or decreased sensitivity to ampicillin, penicillin, ciprofloxacin, and nitrofurantoin 3
• A significant percentage of isolates were resistant to azithromycin, ceftriaxone, clindamycin, cefazolin, and cefamandole 3

Antibiotic Susceptibility Testing

Antibiotic susceptibility testing is important in guiding the choice of antibiotic for intrapartum chemoprophylaxis:

• The susceptibility of GBS to six commonly used antibiotics has been studied, and the results show that all isolates were susceptible to penicillin, ampicillin, cefazolin, and vancomycin 4
• The proportion of isolates susceptible to clindamycin and erythromycin was lower, at 91% and 79%, respectively 4

Current Practices

Current practices in antibiotic prescribing for GBS positive obstetric patients with penicillin allergy have been studied:

• Cefazolin and vancomycin were the most frequently prescribed antibiotics for intrapartum neonatal sepsis prophylaxis in patients with penicillin allergy 5
• Antibiotic susceptibility testing was performed on the GBS isolate in 74.2% of patients with penicillin allergy 5