Dizygotic twins discordant for early-onset Citrobacter koseri and group B streptococcal sepsis

Early-onset neonatal sepsis is usually a multisystem fulminant illness with prominent respiratory symptoms, and typically the infant has acquired the organism from the maternal genital tract during the intrapartum period. In this article, we report a rare case of dizygotic twins where each individual suffered early-onset sepsis caused by a different pathogen. Group B streptococcal (GBS) sepsis was diagnosed in twin A 1 day after birth; sepsis and meningitis caused by Citrobacter koseri was diagnosed in twin B at the age of the 4 days. The mother developed pre-eclampsia and fever and the twins were delivered via cesarean section at 35 week's gestation. Twin A received ampicillin treatment for 14 days and recovered fully. Twin B was treated with ceftriaxone for 4 weeks and follow-up brain ultrasound revealed persistent enlargement of the bilateral-lateral ventricles. When empiric antibiotic is considered for the symptomatic twin of a sibling with early-onset GBS infection, samples of blood and cerebrospinal fluid (CSF) should be obtained for culture study before treatment. Adjustment of antibiotic treatment based on the results of cultures and CSF Gram stain and antibiotic susceptibility test is essential.