Colonization of the Preterm Neonatal Gut with Carbapenem-resistant Enterobacteriaceae and Its Association with Neonatal Sepsis and Maternal Gut Flora

BACKGROUND: Multidrug-resistant Gram-negative neonatal sepsis is associated with high mortality and morbidity. Mucosal colonization with these organisms in hospitals may predispose neonates to septicemia. AIMS: The aim of the study was to determine the prevalence and pattern of colonization of neonatal preterm gut with carbapenem-resistant Enterobacteriaceae and identify risk factors associated with colonization. SETTINGS AND DESIGN: The study was a prospective observational study done in a Level 3 neonatal unit of a tertiary care hospital. METHODS: Stool samples from preterm babies were collected soon after birth and at 1 and 3 weeks of age after consent. Maternal stool sample was collected within 48 h after the delivery. Predetermined antenatal, neonatal, and environmental risk factors were recorded. Isolation and identification of organisms was done in a standardized manner; antibiotic susceptibility was done by the Kirby–Bauer method and results interpreted according to the Clinical and Laboratory Standards Institute guidelines. RESULTS: Seventy-one percent of the babies were colonized by Gram-negative bacteria (GNB) at birth, and 100% were colonized by the end of the 1(st) week. The organisms commonly isolated were Escherichia coli, Klebsiella, NFGNB (Nonfermenting Gram-Negative Bacilli), Pseudomonas, and Enterobacter. Sixty-eight percent of the babies were colonized with extended-spectrum beta-lactamase-producing organisms, and 5% of the babies were colonized with carbapenem-resistant organisms (CROs). In the babies who developed culture-positive sepsis, 21% had concordance of strains in the gut and blood. There was no association between maternal and neonatal colonization. CONCLUSIONS: The results show that neonatal gut is colonized by GNB from birth onward. However, the rate of colonization with CRO is low. An association was also observed between colonization and late-onset sepsis.