Patient and bacterial determinants involved in symptomatic urinary tract infection caused by Escherichia coli with and without bacteraemia.

Risk-factors for bacteraemia were determined in a case-control study of patients with Escherichia coli urinary tract infection. Cases were defined as patients with E. coli urinary source bacteraemia, and controls were chosen from among patients with E. coli urinary tract infection without bacteraemia. Patient characteristics were collected prospectively and the bacterial traits were determined. The phylogenetic background and virulence factors of E. coli isolates did not differ between cases and controls. In multivariate analysis, being female and having a urinary catheter were significantly less prevalent among patients with urinary source bacteraemia than among patients with uncomplicated urinary tract infection.