title: Escherichia coli bacteremia in children: age and portal of entry are the main predictors of severity.
abstract: BACKGROUND
  Escherichia coli bacteremia is a major cause of severe sepsis in children. Little is known about predictors of severity.
  
  
  METHODS
  We analyzed 84 children ≤ 18 years of age with E. coli bacteremia from the prospective COLIBAFI study performed during 2005-2007. The severity of bacteremia was defined as occurrence of death or transfer to intensive care unit. Studied characteristics included age, gender, birth weight, history of prematurity, immunodepression, nosocomial infection, portal of entry, phylogenetic group and subgroup belonging, O-type, virulence gene content and antimicrobial susceptibility. We compared bacterial characteristics in urinary- versus digestive-source bacteremia, in children ≤ 3 versus >3 month of age, and in children versus adults. We also searched for risk factors of severity.
  
  
  RESULTS
  Median age was 2.4 months, 57% males. Most frequent portals of entry were urinary (66.2%) and digestive (19.5%) tracts. Most isolates (63.1%) belonged to B2 phylogroup. Strains in children ≤ 3 months of age exhibited more virulence genes, especially neuC and fyuA/irp2, and were less resistant to antibiotics than in children >3 months of age. Comparing community-acquired urinary-source bacteremia between children and adults, we found that bacteremia were less severe in children, whose strains exhibited a specific virulence gene repertoire and had a higher resistance score than in adults. Seventeen children (20.2%) had a severe bacteremia and 8 died. Non-urinary portal of entry and age ≤ 3 months of age were the only risk factors associated with severity.
  
  
  CONCLUSIONS
  E. coli strains responsible for bacteremia exhibit specific characteristics according to age of children. However, host characteristics and portal of entry are the main determinants of severity of E. coli bacteremia in children, as observed in adults.
authors.affiliation: From the *AP-HP, Hôpital Bichat, Service de Biostatistiques; †IAME, UMR 1137, INSERM, Univ Paris Diderot, Sorbonne Paris Cité; ‡EA 3105, Univ Paris Diderot, Sorbonne Paris Cité; §AP-HP, Hôpital Robert-Debré, Laboratoire de Microbiologie; ¶AP-HP, Hôpital Robert Debré, Service de Néonatologie, Paris; and ‖AP-HP, Hôpital Beaujon, Service de Médecine Interne, Clichy, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Burdet
authors.forename: Olivier
authors.initials: O
authors.lastname: Clermont
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bonacorsi
authors.forename: Cédric
authors.initials: C
authors.lastname: Laouénan
authors.forename: Edouard
authors.initials: E
authors.lastname: Bingen
authors.forename: Yannick
authors.initials: Y
authors.lastname: Aujard
authors.forename: France
authors.initials: F
authors.lastname: Mentré
authors.forename: Agnès
authors.initials: A
authors.lastname: Lefort
authors.forename: Erick
authors.initials: E
authors.lastname: Denamur
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016470:Bacteremia / Q000382:microbiology* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors