Antibiotic Prophylaxis and Treatment of Neonatal Group B Streptococcus Disease in the Era of Antimicrobial Resistance.

Group B Streptococcus (GBS) remains a major cause of early- and late-onset neonatal sepsis worldwide, despite the widespread use of intrapartum antibiotic prophylaxis (IAP). β-lactam antibiotics, including penicillin G and ampicillin, remain the cornerstone of both GBS prophylaxis and neonatal treatment, supported by sustained susceptibility, favorable pharmacokinetics, and extensive clinical experience. However, increasing global resistance to macrolides and lincosamides has markedly reduced the reliability of clindamycin and erythromycin, which are commonly used as second-line agents in women with severe penicillin allergy. This narrative review summarizes current evidence on antibiotic strategies for the prevention and treatment of neonatal GBS disease, with a particular focus on antimicrobial resistance patterns and their clinical implications. Available surveillance data demonstrate substantial geographic variability in resistance but consistently low resistance to β-lactams and vancomycin. These trends have expanded the role of vancomycin in IAP for women with high-risk β-lactam allergy and in neonatal treatment when first-line agents are contraindicated. Alternative agents such as linezolid and teicoplanin exhibit activity against GBS, but their use remains limited by sparse neonatal data and pharmacokinetic variability. Ongoing antimicrobial surveillance, susceptibility-guided therapy, and stewardship initiatives are essential to preserve effective GBS prevention and treatment strategies.