Infect Chemother.  2003 Dec;35(6):365-369.

Antimicrobial Susceptibility of Escherichia coli and Klebsiella pneumoniae Blood Isolates over 5 years:Influence of Extended-Spectrum Beta-Lactamase-Producing Organisms

• Kang CI
• Kim DM
• Yi JY
• Park WB
• Lee KD
• Kim HB
• Oh MD
• Kim EC
• Choe KW

Abstract

BACKGROUND: Escherichia coli and Klebsiella pneumoniae are major Gram-negative pathogens causing bloodstream infection. Antibiotic-resistant mutant strains that produce extended-spectrum beta-lactamase (ESBL) have emerged among E. coli and K. pneumoniae and are increasingly being recognized.
METHODS
The database at the Clinical Microbiology Department was retrospectively reviewed in order to identify the patients with E. coli and K. pneumoniae bacteremia. The archived blood isolates of E. coli and K. pneumoniae, isolated and stored from Jan 1998 to Dec 2002, were tested for ESBL production using the NCCLS guidelines and/or double-disk synergy test, and antimicrobial susceptibility by disk diffusion method using NSSCL guidelines.
RESULTS
A total of 1045 strains of E. coli and 535 strains of K. pneumoniae were analyzed. The antimicrobial susceptibility of E. coli strains were as follows; cefotaxime 91%, ceftazidime 93%, imipenem 100%, amikacin 97%, gentamicin 75%, tobramycin 79%, and ciprofloxacin 75%. The antimicrobial susceptibility of K. pneumoniae strains were as follows; cefotaxime, 84%, ceftazidime, 87%, imipenem, 100%, amikacin, 94%, gentamicin, 87%, tobramycin, 84%, and ciprofloxacin, 87%. The overall prevalence of ESBL-producing organisms was 8.6% in E. coli and 14.2% in K. pneumoniae. In ESBL-producing organisms, all strains were susceptible to imipenem, whereas 40% of K. pneumoniae strains and 30% of E. coli strains were susceptible to ciprofloxacin.
CONCLUSION
The overall prevalence of ESBL-producing organisms was 8.6% in E. coli blood isolates and 14.2% in K. pneumoniae blood isolates. Among the ESBL-producing strains, only 40% of K. pneumoniae strains and 30% of E. coli strains were susceptible to ciprofloxacin.

Keyword

Escherichia coli; Klebsiella pneumoniae; Beta-lactamase; Antimicrobial drug resistance

MeSH Terms

Amikacin
Bacteremia
beta-Lactamases
Cefotaxime
Ceftazidime
Ciprofloxacin
Diffusion
Drug Resistance, Microbial
Escherichia coli*
Escherichia*
Gentamicins
Humans
Imipenem
Klebsiella pneumoniae*
Klebsiella*
Pneumonia
Prevalence
Retrospective Studies
Tobramycin
Amikacin
Cefotaxime
Ceftazidime
Ciprofloxacin
Gentamicins
Imipenem
Tobramycin
beta-Lactamases