Prevalence of ciprofloxacin-resistant Escherichia coli in hematologic-oncologic patients

The objective of this study was to characterize the prevalence and clinical significance of ciprofloxacin-resistant Escherichia coli in perianal swabs of patients with hematologic malignancies in a German university hospital.

Weekly surveillance cultures were performed for 26 weeks. 294 perianal swabs were obtained from 104 consecutive patients. Species discrimination, susceptibility testing and genotyping using pulsed-field gelelectrophoresis (PFGE) was performed for all E. coli isolates. Preceding antibiotic prophylaxis and treatment as well as the frequency and duration of the hospital stay in the 6 months prior to the study were analyzed.

A total of 31 patients (29.8%) were colonized with E. coli. 11 patients (10.6%) carried ciprofloxacin-resistant E.coli strains. Although 81.8% of the patients colonized with ciprofloxacin-resistant E. coli had received former treatment with ciprofloxacin, this finding did not reach statistical significance, probably due to the small study population. During the surveillance period one of the colonized patients developed septicemia with a ciprofloxacin-resistant E. coli. Genotypic identity was demonstrated for the E. coli isolates from perianal swab and blood culture.

We propose that selective gut decontamination with ciprofloxacin should be discontinued as a routine measure for all neutropenic patients in the department under investigation. We propose waiving oral decontamination in low-risk patients with neutropenia of only a few days duration. For all other patients, a regimen with alternating prophylactic treatments of cotrimoxazol and a fluoroquinolone should be considered.