title: [Bacteremia caused by Escherichia coli and Klebsiella pneumoniae producing extended-spectrum betalactamases: mortality and readmission-related factors].
abstract: OBJECTIVE
  The incidence of bloodstream-infections caused by extended-spectrum betalactamases (ESBL)-producing bacteria has increased exponentially. The objective of this study is to determine the factors related to mortality and readmission in these patients.
  
  
  METHODS
  Socio-epidemiological, clinical and laboratory data has been collected (from January, 1st 2008 to April, 31th 2011). They were classified as nosocomial, healthcare-associated or community-acquired data. A descriptive research was conducted to determine the main differences in terms of responsible bacteria and variables associated with mortality and readmission rates. The following techniques were used to compare variables: Student's t-test, one-way ANOVA test, χ(2)-test and Fisher's exact test. A logistic-regression analysis was performed to identify variables independently related to mortality and readmission, using SPSS(®) statistics software v18.
  
  
  RESULTS
  A total of 68 patients were included in the study: 73.5% of the infections were caused by Escherichia coli (E. coli), and 26.5% by Klebsiella pneumoniae (K. pneumoniae). Nosocomial origin, critical condition of patients, and abdominal location were more frequent when K. pneumoniae was isolated; urinary tract was the most frequent site of E. coli infections. The in-hospital mortality reached 20.6%, and 24% during the follow-up period. The main factor associated to in-hospital mortality was previous antibiotic treatment (OR 8.37; CI 95%: 1.094-64.091); within the follow-up period, the first mortality factor was central venous catheterization (OR 8.416; CI 95%: 1.367-51.821). Readmission was required in 55.5% of patients. The main variables associated were nosocomial origin (OR 4.801; CI 95%: 1.057-21.802) and previous antibiotic treatment (OR 4.715; CI 95%: 1.125-19.766). Inadequate antibiotic treatment was not associated with increased mortality or readmission. Conclusions ESBL-producing E. coli and K. pneumoniae bloodstream-infections are linked to a high mortality and readmission risk. Previous antibiotic treatment is the main factor associated to a poor outcome.
authors.affiliation: Servicio de Medicina Interna, Hospital Universitario de Salamanca, Salamanca, España.
authors.forename: María Electra
authors.initials: ME
authors.lastname: Perianes-Díaz
authors.affiliation: Servicio de Medicina Interna, Hospital Universitario de Salamanca, Salamanca, España. Electronic address: ignacio.novo.veleiro@gmail.com.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Novo-Veleiro
authors.affiliation: Servicio de Medicina Interna, Hospital Universitario de Salamanca, Salamanca, España.
authors.forename: Katia
authors.initials: K
authors.lastname: Solís-Díaz
authors.affiliation: Servicio de Medicina Interna, Hospital Universitario de Salamanca, Salamanca, España.
authors.forename: Andrea
authors.initials: A
authors.lastname: Prolo-Acosta
authors.affiliation: Servicio de Microbiología, Hospital Universitario de Salamanca, Salamanca, España.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: García-García
authors.affiliation: Servicio de Medicina Interna, Hospital Universitario de Salamanca, Salamanca, España.
authors.forename: Gloria
authors.initials: G
authors.lastname: Alonso-Claudio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D015415:Biomarkers / Q000378:metabolism; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D004926:Escherichia coli / Q000201:enzymology; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers; D001618:beta-Lactamases
keywords: Bacteremia; Bacteriemia; Betalactamasas de espectro extendido; Escherichia coli; Extended-spectrum betalactamases; Klebsiella pneumoniae; Mortalidad; Mortality; Readmission; Reingreso