title: Relationship of phylogenetic background, biofilm production, and time to detection of growth in blood culture vials with clinical variables and prognosis associated with Escherichia coli bacteremia.
abstract: In patients with Escherichia coli bacteremia, data on the relationship of phylogenetic background, biofilm production, and degree of bacteremia with clinical variables and prognosis are scarce. During a 1-year period, all adults with bacteremia due to Escherichia coli diagnosed at a university center were enrolled. Determination of phylogenetic background, biofilm production, and genotyping was performed with all strains, and the time to positivity of blood culture vials was recorded. A total of 185 episodes of diverse-source E. coli bacteremia was analyzed. Strains of phylogroup D were predominant (52%). Phylogroup A isolates were associated with pneumonia and prior antibiotic intake, B1 with an abdominal source of infection, B2 with the absence of urological abnormalities, and D with urological abnormalities and age below 65 years. Resistance to antibiotics and no biofilm production were concentrated in phylogroup A strains. Biofilm production was not associated with any clinical variable. An immunocompromising condition (odds ratio [OR] = 5.01, 95% confidence interval [CI] = 1.4 to 17.9), peritonitis (OR = 17, 95% CI = 3.32 to 87), pneumonia (OR = 9.97, 95% CI = 1.96 to 50.6), and </=7 h to bacteremia detection (OR = 4.37, 95% CI = 1.38 to 13.8) were the best predictors of a fatal outcome. Results from this study suggest that the distribution of phylogenetic backgrounds among E. coli strains involved in diverse-source bacteremia may be subject to geographical variation and that, in afflicted individuals, some high-risk sources, the patient's underlying condition, and the degree of bacteremia are more important than microbial factors in determining the outcome. Time to positivity of blood culture vials may be a variable of potential clinical impact.
authors.affiliation: Department of Infectious Diseases, Hospital Clínic, Villarroel 170, 08036 Barcelona, Spain. jamarti@clinic.ub.es
authors.forename: Jose A
authors.initials: JA
authors.lastname: Martínez
authors.forename: Sara
authors.initials: S
authors.lastname: Soto
authors.forename: Anna
authors.initials: A
authors.lastname: Fabrega
authors.forename: Manel
authors.initials: M
authors.lastname: Almela
authors.forename: Josep
authors.initials: J
authors.lastname: Mensa
authors.forename: Alex
authors.initials: A
authors.lastname: Soriano
authors.forename: Francesc
authors.initials: F
authors.lastname: Marco
authors.forename: María T
authors.initials: MT
authors.lastname: Jimenez de Anta
authors.forename: Jordi
authors.initials: J
authors.lastname: Vila
mesh_terms: D000368:Aged; D016470:Bacteremia / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D018441:Biofilms / Q000254:growth & development*; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D004927:Escherichia coli Infections / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D011379:Prognosis