Peripartum maternal transmission of extended-spectrum β-lactamase organism to newborn infants.

The aim of this study was to determine whether the route of extended-spectrum β-lactamase (ESBL) transmission to hospitalized newborns was from their mothers during delivery. Neonatal intensive care unit (NICU) hospitalized newborns were sampled for ESBL presence by stool cultures on the first and fourth days of life. Mothers of ESBL-positive newborns were sampled for possible correlation detection. Bacteria isolates were molecularly identified and susceptibility tests for antibiotic agents were performed. Of the 225 newborns, 14 (6.2%) were ESBL positive, 10 (4.4%) were Escherichia coli positive, and 4 (1.7%) were Klebsiella pneumoniae positive. Among the 14 mothers of positive newborns, 13 (92.8%) were found ESBL positive and one mother of a newborn with E. coli carriage was found ESBL negative. Genes encoding for ESBL resistance were identified. Antibiotic sensitivity and resistance were tested. This study demonstrated that ESBL bacteria carrier neonates hospitalized in NICU may be a result of transmission from mother to baby during delivery.