A neonate born at 32 weeks gestation develops temperature instability, poor feeding and bulging fontanelle at 10 days of life. CSF shows 200 cells/mm3 (90% neutrophils), protein 180 mg/dL, glucose 18 mg/dL with concurrent blood glucose of 60 mg/dL. The most likely causative organism in this late-onset neonatal meningitis is:

• A Coagulase-negative Staphylococcus ✓
• B Group B Streptococcus
• C Escherichia coli
• D Listeria monocytogenes

Explanation

Late-onset neonatal sepsis (after 72 hours, especially in premature NICU infants) is most commonly caused by coagulase-negative Staphylococcus (CoNS), particularly Staphylococcus epidermidis, related to line or device colonization. Group B Streptococcus and E. coli predominate in early-onset sepsis (0–72 h). Listeria is rare and typically presents with granulomatosis infantiseptica in early-onset disease. The CSF profile described is consistent with bacterial meningitis.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.