Carbapenem Therapy for Bacteremia due to Extended-spectrum ?-lactamase-producing Escherichia coli or Klebsiella pneumoniae: Implications of Ertapenem Susceptibility.
Antimicrob Agents Chemother. 2012 Mar 19;
Authors: Lee NY, Lee CC, Huang WH, Tsui KC, Hsueh PR, Ko WC
Abstract
A retrospective study was conducted at two medical centers in Taiwan to evaluate clinical characteristics, outcome, and risk factors of mortality among patients treated with a carbapenem for bacteremia caused by extended-spectrum beta-lactamase (ESBL)-producing organisms. A total of 251 patients with bacteremia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae treated by a carbapenem were identified. Among these ESBL-producing isolates, susceptibility rates of ertapenem (MICs ?0.25 ?g/ml) were 83.8% and 76.4%, meropenem 100% and 99.3%, and imipenem 100% and 97.9%, respectively. There were no significant differences in the critical illness (P=0.1) or sepsis-related mortality rate (P=0.2) among bacteremia caused by ESBL-producing K. pneumoniae (140 isolates, 55.8%) and E. coli (111, 44.2%) isolates. Multivariate analysis of variables related to sepsis-related mortality revealed that the presence of severe sepsis (odds ratio [OR], 15.9; 95% confidence interval [CI], 5.84-43.34; P<0.001), hospital-onset bacteremia (OR, 4.65; 95% CI, 1.42-15.24; P=0.01), and ertapenem-nonsusceptible isolates (OR, 5.12; 95% CI, 2.04-12.88; P=0.001) were independent risk factors. The patients receiving inappropriate therapy had a higher sepsis-related mortality than those with appropriate therapy (P=0.002), irrespective of ertapenem, imipenem, or meropenem therapy. Infections due to the ertapenem-susceptible isolates (MICs ?0.25 ?g/ml) were associated with a more favorable outcome than those due to ertapenem-nonsusceptible isolates (MICs >0.25 ?g/ml), if treated by a carbapenem. However, the mortality of bacteremic episodes due to isolates with MICs ?0.5 ?g/ml was similar to those with MICs >0.5 ?g/ml (P=0.8). Such a finding supports the rationale of the current CLSI-2011 criteria of carbapenems for Enterobacteriaceae.
PMID: 22430969 [PubMed - as supplied by publisher]