title: Changes in urine composition after trauma facilitate bacterial growth.
abstract: BACKGROUND
  Critically ill patients including trauma patients are at high risk of urinary tract infection (UTI). The composition of urine in trauma patients may be modified due to inflammation, systemic stress, rhabdomyolysis, life support treatment and/or urinary catheter insertion.
  
  
  METHODS
  Prospective, single-centre, observational study conducted in patients with severe trauma and without a history of UTIs or recent antibiotic treatment. The 24-hour urine samples were collected on the first and the fifth days and the growth of Escherichia coli in urine from patients and healthy volunteers was compared. Biochemical and hormonal modifications in urine that could potentially influence bacterial growth were explored.
  
  
  RESULTS
  Growth of E. coli in urine from trauma patients was significantly higher on days 1 and 5 than in urine of healthy volunteers. Several significant modifications of urine composition could explain these findings. On days 1 and 5, trauma patients had an increase in glycosuria, in urine iron concentration, and in the concentrations of several amino acids compared to healthy volunteers. On day 1, the urinary osmotic pressure was significantly lower than for healthy volunteers.
  
  
  CONCLUSIONS
  We showed that urine of trauma patients facilitated growth of E. coli when compared to urine from healthy volunteers. This effect was present in the first 24 hours and until at least the fifth day after trauma. This phenomenon may be involved in the pathophysiology of UTIs in trauma patients. Further studies are required to define the exact causes of such modifications.
authors.affiliation: Site Xavier Bichat, INSERM U722 and Université Paris 7 Denis Diderot, 16 rue Henri Huchard, Paris 75018, France. cecile.aubron@free.fr
authors.forename: Cecile
authors.initials: C
authors.lastname: Aubron
authors.forename: Olivier
authors.initials: O
authors.lastname: Huet
authors.forename: Sylvie
authors.initials: S
authors.lastname: Ricome
authors.forename: Didier
authors.initials: D
authors.lastname: Borderie
authors.forename: Eric
authors.initials: E
authors.lastname: Pussard
authors.forename: Pierre-Etienne
authors.initials: PE
authors.lastname: Leblanc
authors.forename: Odile
authors.initials: O
authors.lastname: Bouvet
authors.forename: Eric
authors.initials: E
authors.lastname: Vicaut
authors.forename: Erick
authors.initials: E
authors.lastname: Denamur
authors.forename: Jacques
authors.initials: J
authors.lastname: Duranteau
mesh_terms: D000328:Adult; D016638:Critical Illness; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014552:Urinary Tract Infections / Q000652:urine; D014556:Urine / Q000737:chemistry* / Q000382:microbiology*; D014947:Wounds and Injuries / Q000382:microbiology* / Q000652:urine*; D055815:Young Adult