title: Empiric Antibiotics for Serious Bacterial Infection in Young Infants: Opportunities for Stewardship.
abstract: OBJECTIVE
  To evaluate the causative agents of serious bacterial infection (SBI) in young infants and the optimal approach to empiric antibiotic therapy for infants with SBI.
  
  
  METHODS
  From May 1, 2011, to December 1, 2013, pertinent clinical data were collected on previously well infants 60 days or younger with SBI as defined by a positive bacterial culture from a sterile site. Infants were identified by prospective surveillance of admissions and daily review of microbiology records.
  
  
  RESULTS
  Two hundred sixty-five infants with SBI were identified. Mean age was 32 days (SD ±16.6 days). Twenty-nine infants had meningitis, 66 had bacteremia (37 with concomitant urinary tract infection), and 170 had urinary tract infection alone. No methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus sp., or penicillin-resistant Streptococcus pneumoniae were identified. Four extended-spectrum β-lactamase-producing gram-negative bacilli were seen. Empiric therapy was ampicillin and gentamicin (n = 116, 44%) or third-generation cephalosporin based (n = 149, 56%). Ampicillin and gentamicin, with third-generation cephalosporins reserved for cases where meningitis is suspected, would have provided effective coverage for 98.5% of infants and unnecessarily broad therapy for 4.3%. Third-generation cephalosporins with ampicillin would have been effective for 98.5% of infants and unnecessarily broad for 83.8%. Third-generation cephalosporin monotherapy was less effective than either combination (P < 0.001). Fifty-seven percent of broad spectrum empiric therapy was continued despite culture results allowing de-escalation.
  
  
  CONCLUSIONS
  Ampicillin/gentamicin remains an effective empiric regimen for infants 60 days or younger with suspected SBI. Use of a third-generation cephalosporin for suspected meningitis is appropriate, but cerebrospinal fluid must be obtained promptly to guide appropriate therapy.
authors.affiliation: From the *Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX; †Department of Pediatrics, Universidad del Valle and Centro de Estudios en Infectologia Pediatrica, Cali, Colombia; and ‡Department of Pharmacology, Children's Medical Center; §Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Cantey
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lopez-Medina
authors.forename: Sean
authors.initials: S
authors.lastname: Nguyen
authors.forename: Christopher
authors.initials: C
authors.lastname: Doern
authors.forename: Carla
authors.initials: C
authors.lastname: Garcia
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology; D001419:Bacteria / Q000302:isolation & purification; D001424:Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016920:Meningitis, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D011446:Prospective Studies; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents