title: Early empiric antibiotic use in preterm infants is associated with lower bacterial diversity and higher relative abundance of Enterobacter.
abstract: OBJECTIVE
  To determine the impact of empiric ampicillin and gentamicin use in the first week of life on microbial colonization and diversity in preterm infants.
  
  
  METHODS
  The 16s ribosomal DNA community profiling was used to compare the microbiota of 74 infants born ≤32 weeks gestational age by degree of antibiotic use in the first week of life. The degree of antibiotic use was classified as 0 days, 1-4 days, and 5-7 days of antibiotic administration. All of the antibiotic use was empiric, defined as treatment based solely on clinical suspicion of infection without a positive culture result.
  
  
  RESULTS
  Infants who received 5-7 days of empiric antimicrobial agents in the first week had increased relative abundance of Enterobacter (P = .016) and lower bacterial diversity in the second and third weeks of life. Infants receiving early antibiotics also experienced more cases of necrotizing enterocolitis, sepsis, or death than those not exposed to antibiotics.
  
  
  CONCLUSIONS
  Early empiric antibiotics have sustained effects on the intestinal microbiota of preterm infants. Intestinal dysbiosis in this population has been found to be associated with elevated risk of necrotizing enterocolitis, sepsis, or death.
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH; Division of Neonatology, Advocate Children's Hospital, Oak Lawn, IL.
authors: Corryn
authors: C
authors: Greenwood
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH; Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH; Division of Biostatistics and Epidemiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH.
authors: Ardythe L
authors: AL
authors: Morrow
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.
authors: Anne J
authors: AJ
authors: Lagomarcino
authors: Division of Biostatistics and Epidemiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH.
authors: Mekibib
authors: M
authors: Altaye
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH; Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH.
authors: Diana H
authors: DH
authors: Taft
authors: Department of Biology, Boston College, Chestnut Hill, MA.
authors: Zhuoteng
authors: Z
authors: Yu
authors: Department of Biology, Boston College, Chestnut Hill, MA.
authors: David S
authors: DS
authors: Newburg
authors: Broad Institute, Cambridge, MA.
authors: Doyle V
authors: DV
authors: Ward
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH. Electronic address: kurt.schibler@cchmc.org.
authors: Kurt R
authors: KR
authors: Schibler
mesh_terms: D000667:Ampicillin / Q000009:adverse effects / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000627:therapeutic use*; D044822:Biodiversity; D015331:Cohort Studies; D016172:DNA Fingerprinting; D004275:DNA, Ribosomal / Q000235:genetics; D004754:Enterobacter / Q000187:drug effects*; D005260:Female; D005839:Gentamicins / Q000009:adverse effects / Q000627:therapeutic use; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007422:Intestines / Q000382:microbiology*; D008137:Longitudinal Studies; D008297:Male; D064307:Microbiota / Q000187:drug effects*; D009820:Ohio; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004275:DNA, Ribosomal; D005839:Gentamicins; D012336:RNA, Ribosomal, 16S; D000667:Ampicillin