Objectives: The aims of this study were to evaluate risk factors, clinical presentation, outcome and antimicrobial susceptibility in patients with
Escherichia coli bacteremia occurring over seven ...years in a single cancer hospital.
Methods: Sixty five episodes of bacteremia from
E. coli appearing over seven years from 12,301 admissions in a single cancer institution were retrospectively analyzed.
Results: The proportion of bacteremia caused by
E. coli among Gram-negative bacteremia was 20.8% (the second most common organism after
Pseudomonas aeruginosa), and infection-associated mortality was 17%.The incidence in 1989–1995 varied from 14.3 to 24.7%. The most common risk factors were: solid tumors as the underlying disease (70.7%); central venous catheter insertion (32.3%); prior surgery (46.2%), and prior chemotherapy within 48 h (44.4%). Neutropenia and urinary catheters did not place patients at high risk in any of the subgroups. When we compared the two subgroups of 61 cases of bacteremia — monomicrobial and polymicrobial (when
E. coli was isolated from blood culture with another microorganism) — we found that acute leukemia and breakthrough (recurrence while receiving antibiotics) bacteremia were more frequently associated with polymicrobial
E. coli bacteremia. There was also a difference in infection-associated mortality: monomicrobial bacteremia due to
E. coli only had a significantly lower mortality in comparison with polymicrobial
E. coli bacteremia (8.9 vs 35.0%, respectively; P<0.03).
Conclusion: The susceptibility of 115
E. coli strains isolated from 65 episodes of bacteremia was stable. Only two episodes caused by quinolone-resistant strains occurred, both in 1995, after six years of using ofloxacin for prophylaxis in neutropenic patients in our hospital. We found that 85.2–91.3% of all strains were susceptible to aminoglycosides, 97.8% to quinolones, and 90–100% to third generation cephalosporins and imipenems.The patients most commonly infected had solid tumors and the mortality was only 17%.
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