title: Does maternal intrapartum antibiotic treatment prolong the incubation time required for blood cultures to become positive for infants with early-onset sepsis?
abstract: BACKGROUND
  We hypothesized that maternal intrapartum antibiotic treatment delays the growth of the organism in the blood culture obtained during the work-up for infants with suspected early-onset sepsis (EOS).
  
  
  METHODS
  Single center, retrospective review of infants with blood culture-proven EOS over 13.5 years period. EOS was defined by isolation of a pathogen from blood culture obtained within 72 hours of birth and antibiotic treatment for  ≥ 5 days.
  
  
  RESULTS
  Among 81 infants with positive blood cultures, 38 were deemed to have EOS and 43 were deemed contaminants. The organisms grown were as follows: Escherichia coli in 17 infants, Group B streptococcus in 10 infants, and others in 11 infants. Overall, 17 infants with EOS did not receive intrapartum antibiotics and had blood cultures drawn for being symptomatic after birth. The other 21 infants who received intrapartum antibiotics had blood culture drawn primarily for maternal chorioamnionitis. The median (interquartile range [IQR]) incubation time to blood culture positivity was not different in infants who received intrapartum antibiotics compared with infants who did not (19.6 hours, IQR 16-28 hours vs. 19.5 hours, IQR 17.2-21.6 hours, p = 0.7489).
  
  
  CONCLUSIONS
  Maternal intrapartum antibiotic treatment did not delay the time to blood culture positivity in infants with EOS.
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics and Communicable Diseases, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan.
authors.forename: Siddhartha Sean
authors.initials: SS
authors.lastname: Sarkar
authors.affiliation: Department of Pediatrics, University of Wisconsin Hospitals and Clinics, Madison, Wisconsin.
authors.forename: Indira
authors.initials: I
authors.lastname: Bhagat
authors.affiliation: Pharmacy, Pediatrics and Communicable Diseases, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan.
authors.forename: Varsha
authors.initials: V
authors.lastname: Bhatt-Mehta
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics and Communicable Diseases, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan.
authors.forename: Subrata
authors.initials: S
authors.lastname: Sarkar
mesh_terms: D000667:Ampicillin / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis; D002821:Chorioamnionitis / Q000188:drug therapy; D004926:Escherichia coli / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D036801:Parturition; D011247:Pregnancy; D012189:Retrospective Studies; D018805:Sepsis / Q000097:blood* / Q000175:diagnosis*; D013292:Streptococcus agalactiae / Q000302:isolation & purification*
chemical_list: D000667:Ampicillin