Which pathogen is associated with early-onset neonatal pneumonia?

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

Answer: (B)

Early-onset neonatal pneumonia comes from organisms the baby picks up around the time of birth, through the birth canal. The most classic and strongest association is with Group B Streptococcus. When a mother carries GBS, transmission during labor can seed the newborn’s lungs, leading to pneumonia and often sepsis within the first 72 hours of life. This is why prenatal GBS screening and intrapartum antibiotic prophylaxis have such a big impact in reducing these early cases. While other pathogens like Escherichia coli or Listeria monocytogenes can also cause early neonatal infection, Group B Streptococcus remains the best-known link to early-onset pneumonia. Staphylococcus aureus is more commonly linked to skin infections and can cause pneumonia, but not as classically associated with the early-onset neonatal pattern.