Late-Onset Sepsis in Preterm Infants Caused by Clostridium ramosum: A Case Series and Literature Review

Clostridium ramosum is an opportunistic anaerobic gut commensal associated with invasive infections in immunocompromised adults. However, sepsis caused by C. ramosum in newborn infants, especially in preterm infants, is extremely scarce.

A retrospective case series of ten preterm infants with C. ramosum sepsis who were admitted to a neonatal intensive care unit since birth between 2022 and 2024. Clinical data including epidemiologic and demographic characteristics, management, and outcomes were collected. A literature review was also performed on published cases from 2010 to 2025.

All infants were preterm with multiple comorbidities, the median gestational age was 32⁺³ weeks. No significant temporal clustering was observed. Common presentations were feeding intolerance and bloody stool, with 80% of cases having necrotizing enterocolitis (NEC). Laboratory findings showed elevated inflammatory markers. All infants received meropenem-based therapy, and 40% of cases required surgical intervention. No acute infection-related mortality occurred. Literature review of adult cases (n=30) showed a direct mortality of 36.7%, often associated with unresolved infection sources and severe sepsis.

C. ramosum can cause severe sepsis in preterm infants, often associated with NEC. Early recognition, appropriate antimicrobial therapy based on susceptibility testing (e.g., a carbapenem), and prompt surgical intervention when indicated are crucial for favorable outcomes.