A term newborn presents at 12 hours of life with temperature 39.2°C, irritability, and bulging fontanelle. CSF shows 350 cells/mm3 (90% PMN), glucose 18 mg/dL, protein 280 mg/dL. Gram stain shows gram-negative diplococci. Which organism and what is the recommended antibiotic for this condition?

• A Neisseria meningitidis — ceftriaxone
• B Listeria monocytogenes — ampicillin plus gentamicin
• C Group B Streptococcus — benzylpenicillin
• D E. coli K1 — ampicillin plus cefotaxime ✓

Explanation

Gram-negative diplococci in neonatal CSF is classically attributed to E. coli K1 (which can appear as paired cocci on gram stain despite being a rod on closer examination) — E. coli is the most common cause of late-onset gram-negative neonatal meningitis. However, in practice, for neonatal gram-negative meningitis, ampicillin plus cefotaxime is the empirical regimen of choice; ceftriaxone is avoided in neonates as it displaces bilirubin from albumin, increasing risk of kernicterus. Neisseria meningitidis is very rare in the neonatal period. Listeria and GBS are gram-positive.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.