Streptococcus agalactiae

Background

Microbiology

• Gram-positive coccus in chains
• The most common group B Streptococcus of clinical concern
• Identified with the help of a CAMP test, where β-hemolysis is induced by the presence of Staphylococcus aureus

Epidemiology

• Previously the most common cause of neonatal sepsis, until screening and prophylaxis during pregnancy and deliverybecame routine

Clinical Manifestations

Neonatal

• May be either early-onset (< 7 days old) or late-onset (7 to 90 days old)
• Presents with bacteremia, sepsis, pneumonia, and meningitis

Older Children and Adults

• Similar spectrum of illness to Streptococcus pyogenes, including bacteremia
• Rare cause of community-acquired meningitis in adults, with high mortality1
  • Risk factors include immunocompromised state, CSF leak, and endocarditis

Management

• Treated with penicillin, amoxicillin, or a first-generation cephalosporin