Bloodstream infections due to extended-spectrum b-lactamase-producing Escherichia coli and Klebsiella pneumoniae: risk factors and clinical outcome

Abstract number: P2084

Colakoglu S., Turunc T., Aliskan H., Demiroglu Y., Arslan H.

Objectives: The bloodstream infections (BSIs) caused by extended-spectrum b-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae are a worlwide problem for hospitalised patients, since they markedly increase the rates of treatment failure and mortality. The purpose of this study is to evaluate the risk factors and clinical outcomes of BSIs by ESBL-producing E. coli and K. pneumoniae.

Methods: We analysed the episodes of E. coli and K. pneumoniae bacteraemia in Baskent University Adana Research and Practice Center between January 2006 and August 2007. The antibiotic susceptibilities and ESBL production of each isolate was determined by the disk diffusion method, employing the criteria of Clinical and Laboratory Standards Instutute. Descriptive data were extracted from the medical records of the patients with E. coli and K. pneumoniae bacteraemia. The data collected included age, sex, underlying disease, comorbit conditions, primary site of infection, severity of illness as calculated by the Acute Physiology and Chronic health Evaluation (APACHE) II score, duration of hospital stay, antimicrobial regimen, and any antimicrobial therapy in the 30 days prior to onset of bacteraemia. Each BSI episode was classified based upon Centers for Disease Control and Prevention guidelines. The major study outcome was survival status, which was calculated as the mortality rate within 30 days after the onset of bacteraemia.

Results: A total of 118 episodes of E. coli bacteraemia and 41 episodes of K. pneumoniae bacteraemia were identified. Of these, 40.7% (48/118) of the E. coli strains and 31.7% (13/41) of the K. pneumoniae strains were ESBL-producing organisms. Results are summarised in tables 1 and 2.

Conclusion: In our study, the vast majority (76.7%) of the patients acquired their bloodstream infection in the hospital. The patients with BSIs caused by ESBL-producing E. coli and K. pneumoniae strains were more likely to have had longer hospitalisations and ICU stay prior to infection, and to have higher APACHE II score than were the patients with BSIs caused by non-ESBL-producing. The invasive procedures, neutropenia, and previous antibiotic therapy were more common among ESBL-producing group than they were among non-ESBL group. Bacteraemia caused by ESBL-producing strains is associated with higher mortality rate (19.7%) than the non-ESBL group (9.2%).

Table l. Distribution of personal and clinical characteristics of patients with bloodstream infection caused by ESBL-producing and non-ESBL-producing strains of Escherichia coli and Klebsiella pneumoniae.

Table 2. Clinical outcomes for patients with BSIs caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates versus those for patients with BSIs caused by non-ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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