Nationwide cohort of 156 MBL-producing Enterobacterales bloodstream infections.

30-day mortality reached 23%, with ICU admission as a key risk factor.

Early active therapy and source control improved survival outcomes.

Cefiderocol resistance observed in 27.9% of isolates.

Higher level (54.9%) cefiderocol resistance in NDM-5 producing E. coli.

Bloodstream infections (BSI) due to metallo-β-lactamase (MBL)-producing Enterobacterales are linked to high mortality, but data from France remain limited.

We conducted a retrospective multicentre study in 86 French hospitals including 156 adult patients with confirmed BSI due to MBL-producing Enterobacterales (January 2023–February 2025). The primary outcome was 30-day all-cause mortality. Secondary outcomes included in-hospital mortality and resistance profiles. Clinical features, treatment, and mortality risk factors were assessed.

Day-7, 30-day and in-hospital mortality rates were 11.5%, 23.1% and 26.3%, respectively. Common treatments were ceftazidime-avibactam plus aztreonam (n = 91), cefiderocol (n = 24), and other active antibiotics (n = 21). Independent predictors of mortality were ICU admission (aOR 2.96, 95% CI [1.12–7.88]), delay in active therapy (aOR per day 1.19, 95% CI [1.02–1.40]), and lack of source control (aOR 4.0, 95% CI [1.14–14.3]). Among patients receiving active therapy, 30-day mortality did not differ by regimen. Cefiderocol resistance (27.9%) was mainly seen in NDM-producing E. coli strains harbouring penicillin-binding protein 3 (PBP3) modifications and CMY-type β-lactamases.

MBL-producing Enterobacterales BSIs are associated with high mortality. Early appropriate therapy and source control are critical. Resistance to last-line agents such as cefiderocol and aztreonam-avibactam calls for optimised empirical treatment guided by rapid diagnostics.

Carbapenemase-producing enterobacterales

New-Delhi metallo-beta-lactamase

Ceftazidime-avibactam

Cefiderocol

© 2025 The Author(s). Published by Elsevier Ltd.