Which organism is a common cause of neonatal sepsis?

• A. Staphylococcus aureus
• B. Streptococcus agalactiae
• C. Escherichia coli
• D. Listeria monocytogenes

Answer: (A)

Neonatal sepsis is most often driven by organisms transmitted from the mother during delivery. The leading cause is Streptococcus agalactiae (Group B Streptococcus), which commonly colonizes the maternal genital tract and can be passed to the newborn during birth, leading to early-onset sepsis within the first days of life. While Escherichia coli is also a frequent culprit, GBS remains the most common pathogen in this setting. Listeria monocytogenes is important but less common, and Staphylococcus aureus can cause sepsis but is not the top offender. Prevention with maternal GBS screening and intrapartum antibiotic prophylaxis has significantly reduced early-onset neonatal disease.