Comparison of Extended-Spectrum β-Lactamase-ProducingEscherichia coliandKlebsiella pneumoniaeBloodstream Infection Epidemiology

Abstract

Background: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae are main pathogens of bloodstream infection. We compared the epidemiology of ESBL-producing E. coli and K. pneumoniae. Methods: From January 2003 through March 2007, we retrospectively investigated the clinical characteristics and comorbidities of patients with bloodstream infection by ESBL-producing E. coli and K. pneumoniae. Results: During the study period, 79 patients (54 with E. coli and 25 with K. pneumoniae) with blood cultures positive for ESBL-producing E. coli or K. pneumoniae were studied. When comparing the source of bloodstream infections, urinary tract infections (UTIs) were more commonly caused by E. coli (24% vs. 0; P=0.007), and respiratory tract and soft tissue infection (36% vs. 15%; P=0.04, 12% vs. 0; P=0.03, respectively) were more commonly associated with K. pneumoniae. Among hospital-acquired bloodstream infection, third-generation cephalosporin was more commonly used in patients with E. coli than patients with K. pneumoniae (81% vs. 24%, P<0.001). Medical devices (central venous catheter and urinary catheter) were more commonly used in patients with K. pneumoniae. Conclusion: ESBL-producing E. coli bloodstream infection is more common in urinary tract infections. ESBL-producing K. pneumoniae is more common in respiratory tract infections and in skin and soft tissue infections. In hospital-acquired infections, ESBL-producing E. coli bloodstream infection is more common in biliary tract infection. ESBL-producing E. coli was more commonly associated with prior frequent antibiotics use and K. pneumoniae was more commonly associated with use of medical devices.