Harris PNA, et al. – Authors here described the regional differences in therapy for bloodstream infection (BSI) caused by extended–spectrum β–lactamase–producing Enterobacteriaceae (ESBL–E) or carbapenemase–producing Enterobacteriaceae (CPE). Findings revealed existence of regional variation in therapy for BSI caused by ESBL–producers or CPE, even after adjustment for patient factors. A better understanding of what influenced therapeutic choices for these infections would aid antimicrobial stewardship efforts.

• Authors included 1,482 patients in 12 countries from an observational study of BSI caused by ESBL–E or CPE.
• They used multivariate logistic regression to calculate adjusted odds ratios (aORs) for the influence of country of recruitment on empirical use of β–lactam/β–lactamase inhibitors (BLBLI) or carbapenems, targeted use of BLBLI for ESBL–E and use of targeted combination therapy for CPE.
• BLBLI for empirical therapy was used least frequently in sites from Israel (aOR 0.34, 95% CI 0.14–0.81), Greece (aOR 0.49, 95% CI 0.26–0.94) and Canada (aOR 0.31, 95% CI 0.11–0.88) but more likely in Italy (aOR 1.58, 95% CI 1.11–2.2) and Turkey (aOR 2.09, 95% CI 1.14–3.81), compared to Spain as a reference.
• They observed more frequent use of empirical carbapenems in sites from Taiwan (aOR 1.73, 95% CI 1.03–2.92) and USA (aOR 1.89; 95% CI 1.05–3.39), and less likely in Italy (aOR 0.44, 95% CI 0.28–0.69) and Canada (aOR 0.10, 95% CI 0.01–0.74).
• In sites from Italy, targeted BLBLI for ESBL–E was more frequently used.
• In this study, treatment at sites within Israel, Taiwan, Turkey and Brazil was associated with less combination therapy for CPE.