Microbiologic and Clinical Comparison of Patients Harboring <i>Escherichia coli</i> Blood Isolates with and without Extended-Spectrum <i>β</i>-Lactamases

Abstract

The clinical and microbiologic characteristics of 34 patients with extended-spectrum β-lactamase (ESBL) positive E. coli isolated from blood were compared to 66 bacteremic patients with ESBL negative E. coli, from January 2007 through December 2009. Of the 21 ESBL positive isolates available for PCR analysis, 13 were positive for CTX-M, 8 for TEM, 4 for SHV β-lactamases, with 6 possessing multiple enzymes. Twenty of 34 (59%) ESBL-positive and 41 of 66 (62%) ESBL-negative blood isolates were considered community-associated. All but one isolate in both groups had MICs of ≤1.0 µg/ml to meropenem. However, when compared to ESBL-negative isolates, ESBL-positive isolates were more frequently resistant to levofloxacin, trimethoprim/sulfamethoxazole and had higher MICs to gentamicin, tobramycin and piperacillin/tazobactam. The use of intravenous and urinary catheters was strongly associated with the isolation of E. coli bloodstream isolates in both groups of patients. Although hospital stay was similar in both groups, appropriate therapy was given in 87% of patients with ESBL positive vs. 98% of patients with ESBL negative isolates and mortality was greater for patients with ESBL positive isolates (26% vs. 17%). Since a large proportion of E. coli blood isolates were ESBL-positive and community-associated, carbapenems should be considered as initial empiric therapy for such infections in our locale.

Evaluation of the health and healthcare system burden due to antimicrobial-resistant Escherichia coli infections in humans: a systematic review and meta-analysis

“…However, only five studies could be included in the meta-analysis; they reported total LOS results as a mean with standard deviation [ 40 , 75 , 89 , 92 , 95 ]. Eight studies could not be included in the meta-analysis because they reported total LOS using a median and interquartile range [ 74 , 90 , 94 , 97 , 99 ], or did not consistently report both a measure of central tendency and variability [ 43 , 88 , 108 ]. The five included studies reported an increase in the mean LOS in the third-generation cephalosporin-resistant patients compared to third-generation cephalosporin-susceptible patients, and the mean difference was significant in four of the five studies.…”