Which pair of pathogens are commonly involved in meningitis in neonates?

• A. Neisseria meningitidis and Streptococcus pneumoniae
• B. Haemophilus influenzae and Listeria monocytogenes
• C. Group B Streptococcus and Listeria monocytogenes
• D. Group B Streptococcus and Escherichia coli

Answer: (D)

Neonatal meningitis is most often due to organisms acquired at birth from the mother’s flora. The two pathogens most commonly responsible are Group B Streptococcus and Escherichia coli. Group B Streptococcus frequently colonizes the maternal birth canal and can invade the neonatal CNS during delivery, while E. coli is a common member of the newborn gut and can reach the meninges in the perinatal period. Together they account for the majority of meningitis cases in the first weeks of life. Other organisms like Neisseria meningitidis and Streptococcus pneumoniae tend to cause meningitis in older children and adults, Haemophilus influenzae has become less common due to vaccination, and Listeria monocytogenes can occur but is less prevalent than the GBS–E. coli combination.