Bacteremia due to extended-spectrum beta-lactamase-producing Enterobacteriaceae other than Escherichia coli and Klebsiella

Abstract

Background and purpose: Carbapenems are considered the drugs of choice for the treatment of serious infections caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella and Escherichia coli. However, controversy exists about the antibiotic choice for infections due to ESBL-producing organisms of other genera.

Methods: This retrospective study evaluated the risk factors and outcomes of 54 adult patients with bacteremia due to ESBL-producing Enterobacteriaceae other than Klebsiella spp. or E. coli treated at a tertiary care hospital in northern Taiwan from January 2001-December 2003. Patients were categorized into carbapenem (n = 22) and non-carbapenem (n = 32) treatment groups. All patients had at least one positive blood culture together with fever or other clinical features compatible with systemic infection.

Results: Higher Acute Physiology and Chronic Health Evaluation II score, glucocorticoid use, and presentation of septic shock were significant risk factors for mortality (p<0.05). Patients treated with a carbapenem had a better 14-day or overall survival rate (i.e., survived to discharge) than those treated with non-carbapenem antibiotics, although this difference was not significant. Among patients in the non-carbapenem group, the overall survival rates of ciprofloxacin, aminoglycoside, and ceftazidime were 70% (14/20), 62.5% (5/8), and 50% (2/4), respectively (p=0.877). The overall survival rates of the carbapenem (72.7%) and ciprofloxacin (70.0%) groups were similar.

Conclusions: The results suggest that ciprofloxacin, when indicated based on antimicrobial susceptibility testing, may serve as an alternative choice for infections caused by ESBL-producing Enterobacteriaceae other than E. coli or Klebsiella spp. and may not affect the clinical outcome at discharge.