Fecal Carriage and Intrafamilial Spread of Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae Following Colonization at the Neonatal ICU

Abstract

OBJECTIVE: Fecal carriage of extended-spectrum β-lactamase-producing enterobacteriaceae may contribute to the spread of extended-spectrum β-lactamase-producing enterobacteriaceae into the community. The objective of this study was to assess the duration of fecal carriage after discharge and the occurrence of intrafamilial transmission. DESIGN: Case series. SETTING: Quaternary care children's hospital. PATIENTS: Patients colonized with extended-spectrum β-lactamase-producing enterobacteriaceae at the neonatal ICU and the respective household members. INTERVENTIONS: Screening for intestinal extended-spectrum β-lactamase-producing enterobacteriaceae colonization was done at 1, 2, 4, 6, 9, and 12 months after discharge. Genetic relatedness of isolated extended-spectrum β-lactamase-producing enterobacteriaceae strains was determined using automated rep-PCR. RESULTS: Twenty-five neonates (case-patients) colonized with extended-spectrum β-lactamase-producing enterobacteriaceae (one extended-spectrum β-lactamase-Escherichia coli; six extended-spectrum β-lactamase-Klebsiella pneumoniae; 11 extended-spectrum β-lactamase-Klebsiella oxytoca; and seven extended-spectrum β-lactamase-Serratia marcescens) were included. Duration of fecal carriage was longer (up to 1 yr) in case-patients colonized with Klebsiella species than in case-patients colonized with Serratia marcescens (<4 months). During follow-up, strains and species of extended-spectrum β-lactamase-producing enterobacteriaceae different from the primary strain were found in four and three case-patients, respectively. In nine of 49 (18.4%) included household members, extended-spectrum β-lactamase-producing enterobacteriaceae were found during the follow-up period. In two of nine colonized household members, the isolated extended-spectrum β-lactamase-producing enterobacteriaceae was identical to the primary strains of the respective case-patients. CONCLUSIONS: After intestinal colonization with extended-spectrum β-lactamase-producing enterobacteriaceae at the neonatal ICU, infants potentially remain carriers during the first year after discharge. Intrafamilial spread has been proven.