title: Neonatal Escherichia coli Bloodstream Infections: Clinical Outcomes and Impact of Initial Antibiotic Therapy.
abstract: BACKGROUND
  Escherichia coli is a common cause of bloodstream infections (BSIs) in infants and is associated with high mortality and morbidity among survivors. The clinical significance of antibiotic resistance and timing of appropriate antimicrobial therapy in this population is poorly understood.
  
  
  METHODS
  We identified all infants with E. coli BSIs discharged from 77 neonatal intensive care units managed by the Pediatrix Medical Group in 2012. We used multivariable logistic regression to evaluate the association between 30-day mortality and ampicillin-resistant E. coli BSI, as well as the number of active empiric antimicrobial agents administered, controlling for gestational age, small-for-gestational age status, early-onset versus late-onset BSI, oxygen requirement, ventilator support and inotropic support on the day of the first positive blood culture.
  
  
  RESULTS
  We identified 258 episodes of E. coli BSI, including 123 (48%) ampicillin-resistant isolates. Unadjusted 30-day mortality did not significantly differ between infants with ampicillin-resistant versus ampicillin-susceptible E. coli BSI [11 of 123 (9%) vs. 7 of 135 (5%); P = 0.33; adjusted odds ratio = 1.37 (95% confidence interval: 0.39, 4.77)]. Among ampicillin-resistant E. coli BSIs, 30-day mortality was not significantly lower for infants treated with at least one empiric antimicrobial active against ampicillin-resistant E. coli versus infants receiving no active empiric agent [adjusted odds ratio = 1.50 (0.07, 33.6)].
  
  
  CONCLUSIONS
  In this population of infants with E. coli BSI, ampicillin resistance was not associated with significantly increased mortality. Among the subset of infants with ampicillin-resistant E. coli, appropriate empirical antibiotic therapy was not associated with lower mortality.
authors.affiliation: From the *Department of Medicine, †Department of Pediatrics, and ‡Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina; and §Pediatrix-Obstetrix Center for Research and Education, Sunrise, Florida.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Bergin
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Thaden
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Ericson
authors.forename: Heather
authors.initials: H
authors.lastname: Cross
authors.forename: Julia
authors.initials: J
authors.lastname: Messina
authors.forename: Reese H
authors.initials: RH
authors.lastname: Clark
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Benjamin
authors.forename: Christoph P
authors.initials: CP
authors.lastname: Hornik
authors.forename: P Brian
authors.initials: PB
authors.lastname: Smith
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects*; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents