Antimicrobial Resistances of Escherichia coli Isolates Causing Bacteremia (2004-2009)
Introduction: Escherichia coli is the most frequently isolated microorganism causing nosocomial and community-onset bacteremia. The aim of the present study was to investigate antimicrobial resistance trends of E. coli isolates causing bacteremia. Materials and Methods: In this retrospective study c...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Bilimsel Tip Yayinevi
2010-12-01
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| Series: | Flora Infeksiyon Hastalıkları ve Klinik Mikrobiyoloji Dergisi |
| Subjects: | |
| Online Access: | http://www.floradergisi.org/getFileContent.aspx?op=REDPDF&file_name=2010-15-4-147-152.pdf |
| Summary: | Introduction: Escherichia coli is the most frequently isolated microorganism causing nosocomial and community-onset bacteremia. The aim of the present study was to investigate antimicrobial resistance trends of E. coli isolates causing bacteremia. Materials and Methods: In this retrospective study conducted at the University of Mersin, antimicrobial resistances were evaluated in a total of 323 E. coli isolates causing bacteremia between January 2004 and January 2010. All E. coli species were isolated from the blood using the BACTEC 9240 system (Becton Dickinson, INC, Sparks, MD). Isolates were identified and antimicrobial susceptibility testing was performed using standard techniques. Extended-spectrum beta-lactamase production was assessed by the double-disk synergy test. Nosocomial bacteremia was defined as an infection not present or incubating at the time of hospital admission, with onset at least 48 hours after admission to the hospital. Antimicrobial resistance trends of E. coli isolates during two three-year periods (2004- 2006 and 2007-2009) were prospectively recorded, evaluated and compared. SPSS ver. 16 (Chicago, IL) statistical package program was used for statistical analysis. Results: Patients were analyzed; 58.2% were male, the mean age was 52.7 ± 24.7 (1-96) years, and duration of bacteremia was 7.9 ± 4.6 (1-23). Of these patients, 92.3% had nosocomial bacteremia due to E. coli. Overall mortality was 27.2%. Extended-spectrum beta-lactamase-producing strains were reported in 136 (42.1%) cases. During the six-year study period, resistance rates of E. coli isolates causing bacteremia increased from 42.6% to 67.9% for cefuroxime axetil (p=0.002), from 42.3% to 62.3% for trimethoprimsulfamethoxazole (p=0.003), from 37% to 57.9% for ciprofloxacin (p= 0.018), and from 29.6% to 53.6% for gentamicin (p=0.004). Resistance rates to imipenem remained very low and stable (from 1.1% to 1.9%). Quinolone resistance was significantly associated with extended- spectrum beta-lactamase-production (p=0.0001). Conclusion: We demonstrated a trend of increasing resistance among E. coli isolates causing bacteremia to four different classes of antimicrobials. Increasing resistance may have an impact on the choice of empirical antimicrobial therapy in patients with bacteremia. |
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| ISSN: | 1300-932X 1300-932X |