The assosiation of necrotizing enterocolitis with integrons and antibiotic resistance genes in the gut microbiota of preterm infants

Abstract

Preterm infants are more susceptible to colonization by opportunistic pathogens that may result in necrotizing enterocolitis (NEC). This condition is associated with high morbidity and mortality and often requires excessive antibiotic treatment. Antibiotic treatments can disturb the microbiota and select for antibiotic resistant bacteria. The knowledge about the prevalence of these bacteria and antibiotic resistance genes in the preterm gut microbiota and their contribution in the development of NEC is limited. Therefore, this study investigates the prevalence and persistence of integrons - genetic elements harboring antibiotic resistance genes - in the fecal microbiota from a cohort of preterm infants with and without NEC. Through quantitative PCR and shotgun metagenome sequencing, we detected a higher abundance of integrons, persistence of integrons in several patients and a variety of antibiotic resistance genes in the preterm infants with NEC. Therefore, it is reason to believe that integrons can be associated with NEC. In addition, taxonomic classification through 16S rRNA sequencing revealed a significantly higher abundance of Escherichia coli in the preterm infants with NEC. This bacterium has previously been associated with NEC in other studies. However, this study is of our knowledge the first to associate integrons with NEC. It therefore provides a foundation for further understanding about the preterm gut microbiota as a reservoir for antibiotic resistance genes and integrons, as this may play an important role in the pathogenesis of NEC.