Organisms: GBS > E. coli > Listeria (and other gram-negatives in preterms).
Item
Choice
Empiric
IV ampicillin + gentamicin
Meningitis suspected / CSF abnormal
Ampicillin + cefotaxime (or ceftazidime/cefepime where cefotaxime unavailable) ± gentamicin
Culture negative, baby well
Stop at 36–48 h
GBS bacteremia
Penicillin G or ampicillin 10 days
Gram-negative bacteremia
10–14 days, by sensitivity
Any ill-appearing newborn: blood culture and antibiotics now. Well-appearing at-risk babies (PROM >18 h, chorioamnionitis, inadequate GBS prophylaxis): risk calculator or close observation.
Ampicillin is always part of neonatal empiric therapy because Listeria is resistant to all cephalosporins. Avoid ceftriaxone in neonates (bilirubin displacement; precipitates with IV calcium).
Late-onset neonatal sepsisAfter 72 h–7 days: community vs NICU acquiredFREENeonatology
Setting
Likely organisms
Empiric
Home (term baby, 1–4 weeks)
GBS, E. coli, Listeria, S. aureus
Ampicillin + gentamicin; ampicillin + cefotaxime if meningitis possible
NICU, central line, preterm
CoNS, S. aureus (MRSA), Klebsiella, Pseudomonas, Candida
Vancomycin + gentamicin (or + cefepime/meropenem by unit flora)
Vesicles, seizures, high ALT, CSF pleocytosis
HSV
Add IV acyclovir
Do a full work-up: blood culture, urine culture (catheter/SPA), LP. Remove infected lines. Persistent fever/thrombocytopenia on antibiotics in an extremely preterm baby on broad-spectrum agents: think Candida (amphotericin B/fluconazole).
Late-onset GBS (7–89 days) presents as bacteremia or meningitis; intrapartum prophylaxis prevents early-onset but NOT late-onset GBS.
Neonatal meningitisGBS, E. coli, Listeria — regimen and durationFREENeonatology
Empiric: IV ampicillin (meningitic dose 300 mg/kg/day) + cefotaxime; ampicillin + gentamicin is acceptable if cefotaxime is not an option (bank answer when cefotaxime is not offered).
Organism
Definitive
Duration
GBS
Penicillin G or ampicillin
14 days
Listeria
Ampicillin + gentamicin
14–21 days
E. coli / gram-negatives
Cefotaxime (meropenem if ESBL)
21 days (or 14 days after sterile CSF, whichever longer)
Repeat LP at 24–48 h for gram-negative meningitis; MRI near the end of treatment; hearing test before discharge.
Dexamethasone is not recommended in neonatal meningitis. Citrobacter/Cronobacter meningitis = brain abscess — image.