title: Developmental dynamics of the preterm infant gut microbiota and antibiotic resistome.
abstract: Development of the preterm infant gut microbiota is emerging as a critical research priority(1). Since preterm infants almost universally receive early and often extended antibiotic therapy(2), it is important to understand how these interventions alter gut microbiota development(3-6). Analysis of 401 stools from 84 longitudinally sampled preterm infants demonstrates that meropenem, cefotaxime and ticarcillin-clavulanate are associated with significantly reduced species richness. In contrast, vancomycin and gentamicin, the antibiotics most commonly administered to preterm infants, have non-uniform effects on species richness, but these can be predicted with 85% accuracy based on the relative abundance of only two bacterial species and two antibiotic resistance (AR) genes at treatment initiation. To investigate resistome development, we functionally selected resistance to 16 antibiotics from 21 faecal metagenomic expression libraries. Of the 794 AR genes identified, 79% had not previously been classified as AR genes. Combined with deep shotgun sequencing of all stools, we find that multidrug-resistant members of the genera Escherichia, Klebsiella and Enterobacter, genera commonly associated with nosocomial infections, dominate the preterm infant gut microbiota. AR genes that are enriched following specific antibiotic treatments are generally unique to the specific treatment and are highly correlated with the abundance of a single species. The most notable exceptions include ticarcillin-clavulanate and ampicillin, both of which enrich for a large number of overlapping AR genes, and are correlated with Klebsiella pneumoniae. We find that all antibiotic treatments are associated with widespread collateral microbiome impact by enrichment of AR genes that have no known activity against the specific antibiotic driver.
authors: Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri, USA.
authors: Molly K
authors: MK
authors: Gibson
authors: Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri, USA.|Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri, USA.
authors: Bin
authors: B
authors: Wang
authors: Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri, USA.|Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri, USA.
authors: Sara
authors: S
authors: Ahmadi
authors: Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri, USA.|Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, USA.
authors: Carey-Ann D
authors: CA
authors: Burnham
authors: Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, USA.|Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA.
authors: Phillip I
authors: PI
authors: Tarr
authors: Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, USA.
authors: Barbara B
authors: BB
authors: Warner
authors: Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri, USA.|Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri, USA.|Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA.|Department of Biomedical Engineering, Washington University, St Louis, Missouri, USA.
authors: Gautam
authors: G
authors: Dantas
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D041981:Gastrointestinal Tract / Q000382:microbiology*; D005798:Genes, Bacterial; D006801:Humans; D007234:Infant, Premature; D008137:Longitudinal Studies; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents