552 - Impact of early antibiotic exposure on the risk of colonization with potential pathogens in very low birth weight infants: a retrospective cohort analysis

Poster Number: 552
Publication Number: 552.428

Caren Bubser, Universitätsklinikum Tübingen, Neonatologie der Klinik für Kinder- und Jugendmedizin, Tübingen, Baden-Wurttemberg, Germany; Christian F. Poets, Tuebingen University Hospital, Tuebingen, Baden-Wurttemberg, Germany; Natascha Köstlin-Gille, University Children´s Hospital Tübingen, Tübingen, Baden-Wurttemberg, Germany; Christian Gille, Heidelberg University Childrens Hospital, Heidelberg, Baden-Wurttemberg, Germany

Background: Sepsis is one of the most important complications in preterm infants. Preterm infants have an increased vulnerability to infections because of an immaturity of their mucosal barriers and alterations in their immune responses compared to adults. For this reason, most preterm infants receive antibiotics during their first postnatal week. Since 2013, a weekly colonization screening has been installed in German neonatal intensive care units (NICUs), including multi-drug resistant organisms (MDRO) and pathogens with increased epidemic potential (Serratia marcescens, P. aeruginosa, Enterobacter spp.). We here investigated the impact of early antibiotic exposure on the colonization with these pathogens.

Objective: We investigated the impact of early antibiotic exposure on the colonization with multi-drug resistant organisms (MDRO) and pathogens with increased epidemic potential (Serratia marcescens, P. aeruginosa, Enterobacter spp.).

Design/Methods: We conducted a retrospective cohort analysis using prospectively collected data. Data from 1407 preterm infants with gestational age < 32 0/7 weeks born in three German NICUs between January 2014 and December 2019 were analysed. Infants who died before postnatal day 35 were excluded. Data on antibiotic therapy were collected for all infants from birth up to postnatal day 7. Any dose of an intravenously or orally administered antibiotic during this period was classified as “antibiotic therapy in the first postnatal week”. Screening targeted pathogens (STP) were defined according to the recommendations of the German Commission for Hospital Hygiene and Infection Prevention (KRINKO). From all infants included, weekly throat and anal/rectal swabs were taken and screened for the indicated STP. Any pathogen detection up to and including day 35 after birth was recorded.

Results: Antibiotics were administered to 64.7% of all included infants during their first postnatal week. STP were detected in 38.9% of participants. Early antibiotic exposure did not increase the risk of colonization with STP. The only independent risk factor for colonisation with potential pathogens was the perinatal center. Interestingly, longer antibiotic therapy (> seven days) decreased the risk for acquiring pathogens with increased epidemic potential.Conclusion(s): Early antibiotic exposure did not impact the risk for colonization with MDRO or highly epidemic bacterial pathogens in preterm infants. Further studies are needed to identify risk factors for the acquisition of MDRO and highly epidemic pathogens and potential associations with long-term outcome.