title: β-Lactam/β-lactam inhibitor combinations for the treatment of bacteremia due to extended-spectrum β-lactamase-producing Escherichia coli: a post hoc analysis of prospective cohorts.
abstract: BACKGROUND
  Extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) is an important cause of invasive infections. Alternatives to carbapenems--considered the drugs of choice--are needed because of the emergence of carbapenemase-producing enterobacteria. The efficacy of ß-lactam/ß-lactam inhibitors (BLBLI) in such infections is controversial.
  
  
  METHODS
  The authors performed a post hoc analysis of patients with bloodstream infections due to ESBL-EC from 6 published prospective cohorts. Mortality and length of hospital stay in patients treated with an active BLBLI (amoxicillin-clavulanic acid [AMC] and piperacillin-tazobactam [PTZ]) or carbapenem were compared in 2 cohorts: the empirical therapy cohort (ETC) and the definitive therapy cohort (DTC). Confounding was controlled by multivariate analysis; for patients in the ETC, a propensity score for receiving carbapenem was also used.
  
  
  RESULTS
  The ETC included 103 patients (BLBLI, 72; carbapenem, 31), and the DTC included 174 (BLBLI, 54; carbapenem, 120). Mortality rates at day 30 for those treated with BLBLI versus carbapenems were 9.7% versus 19.4% for the ETC and 9.3% versus 16.7% for the DTC, respectively (P > .2, log-rank test). After adjustment for confounders, no association was found between either empirical therapy with BLBLI (adjusted hazard ratio [HR], 1.14; 95% confidence interval [CI], .29-4.40; P = .84) or definitive therapy (adjusted HR, 0.76; 95% CI, .28-2.07; P = .5) and increased mortality. Furthermore, BLBLI therapy, with respect to carbapenem, was not found to influence length of hospital stay.
  
  
  CONCLUSIONS
  These results suggest that AMC and PTZ are suitable alternatives to carbapenems for treating patients with bloodstream infections due to ESBL-EC if active in vitro and would be particularly useful as definitive therapy.
authors: Unidad Clínica de Enfermedades Infecciosas y Microbiología, Hospital Universitario Virgen Macarena, Spain. jesusrb@us.es
authors: Jesús
authors: J
authors: Rodríguez-Baño
authors: María Dolores
authors: MD
authors: Navarro
authors: Pilar
authors: P
authors: Retamar
authors: Encarnación
authors: E
authors: Picón
authors: Álvaro
authors: Á
authors: Pascual
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use; D000077725:Piperacillin, Tazobactam Drug Combination; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013030:Spain / Q000453:epidemiology; D018440:beta-Lactam Resistance; D065093:beta-Lactamase Inhibitors
chemical_list: D000900:Anti-Bacterial Agents; D065093:beta-Lactamase Inhibitors; D000077725:Piperacillin, Tazobactam Drug Combination; D019980:Amoxicillin-Potassium Clavulanate Combination; D010397:Penicillanic Acid; D010878:Piperacillin