Neonatal antibiotic resistance

The standard prophylactic use of antibiotics in newborns to prevent early-onset sepsis can adversely affect the neonatal gut microbiome, with potential long-term health impacts. Research into the escalating issue of antimicrobial resistance in preterm infants and antibiotic practices in neonatal intensive care units (NICUs) is limited. A deeper understanding of the effects of early antibiotic intervention on antibiotic resistance in preterm infants is crucial. This retrospective study employed metagenomic sequencing to evaluate antibiotic resistance genes (ARGs) in the meconium and subsequent stool samples of preterm infants enrolled in the Routine Early Antibiotic Use in Symptomatic Preterm Neonates (REASON) study. Microbial metagenomics was conducted using a subset of fecal samples from thirty preterm infants for taxonomic profiling and ARG identification. All preterm infants exhibited ARGs, with 175 unique ARGs identified, predominantly associated with Beta-lactam, Tetracycline, and Aminoglycoside resistance. Notably, 23% of ARGs were found in preterm infants without direct or intrapartum antibiotic exposure. Postnatal exposure to antibiotics increases the beta-lactam and tetracycline resistance. Microbial profiling revealed 774 bacterial species, with antibiotic-naive Preterm infants showing higher alpha diversity (p =0.005) in their microbiota and resistome compared to the treatment group, suggesting a more complex ecosystem. High ARG prevalence in Preterm infants was observed irrespective of direct antibiotic exposure and intensifies with age. Prolonged membrane ruptures and maternal antibiotic use during gestation and delivery are linked to alterations in the preterm infant resistome and microbiome, which are pivotal in shaping the ARG profiles in the neonatal gut.