= 28). The overall 30-day mortality rate was 21.9%, with 16.7% (95% confidence interval CI, 2.1%-48.4%) in the DTR group and 23.1% (95% CI, 12.5%-36.8%) in the non-DTR group. DOOR outcomes were similar between groups. Appropriate empiric and definitive therapy was less frequently administered in the DTR group. In this cohort, where IMP-type carbapenemases and non-DTR CRE are prevalent, DTR classification did not appear to correlate with 30-day mortality or DOOR outcomes. These findings underscore the importance of regional molecular epidemiology when interpreting clinical outcomes of CRE infections.IMPORTANCEDifficult-to-treat resistance (DTR) is increasingly used to assess the clinical impact of antimicrobial resistance, but its significance in carbapenem-resistant Enterobacterales (CRE) may vary across molecular epidemiologic settings. In this prospective multicenter study from Japan, where IMP-type carbapenemases predominated, most CRE infections were classified as non-DTR. Whole-genome sequencing also revealed a distinct local clonal structure. DTR was not associated with 30-day mortality or desirability of outcome ranking despite lower rates of appropriate empiric and definitive therapy. Our study highlights the importance of interpreting DTR in CRE within the context of regional molecular epidemiology and supports the need for continued regional multicenter studies to evaluate its clinical utility.
Ohyama et al. (Mon,) studied this question.