Oral Antibiotic Transition in Patients with Bacteremia with a Urinary Source Due to Extended-Spectrum beta-Lactamase-Producing Escherichia coli

Transitioning from intravenous to oral antibiotic therapy for Escherichia coli bacteremia could reduce the length of hospital stay and drug costs without compromising efficacy. Despite the expansion of extended-spectrum beta-lactamase (ESBL)-producing E. coli, limited data are available regarding the effectiveness of switching to oral antibiotic therapy in patients with bacteremia caused by this organism. To compare clinical outcomes between oral transition therapy and intravenous therapy in patients with bacteremia due to ESBL-producing E. coli with a urinary source, we conducted a retrospective cohort study at 3 Japanese hospitals. The effects were estimated by Cox hazard analysis using propensity scores. Among 996 patients with bacteremia due to E. coli, 73 were included in the study. In the adjusted analysis weighted by propensity scores including 26 patients in the oral switch group and 47 in the intravenous group, oral transition did not increase the risk of treatment failure within 60 days (adjusted hazard ratio 0.86, 95% confidence interval 0.18-4.10), whereas the length of hospital stay was shorter in the oral switch group than in the intravenous group (median, 12 days vs. 19 days, P = 0.04). Intravenous-to-oral transition may be an effective treatment option that shortens the hospital stay.