Carmeli Y, Price M, Daikos GL, Falcone M, Gales AC, Hagel S, Omrani AS, Ramirez P, Todi S, Wang M, Gheorghe M, Hauber B, Little CJ, Townsend A. Management of metallo-β-lactamase-producing Enterobacterales infections: a modified Delphi study. JAC-Antimicrob Resis. 2026 Mar 2;8(1):dlag030. doi: 10.1093/jacamr/dlag030

BACKGROUND AND OBJECTIVES: Metallo-β-lactamase (MBL)-producing Enterobacterales infections are an urgent global healthcare problem with limited treatment options. To obtain greater understanding of international perspectives on optimal management of serious infections due to MBL-producing Enterobacterales, we used a modified Delphi process to elicit experts' opinion and establish consensus.

METHODS A Delphi panel comprising 10 expert physicians experienced in antimicrobial-resistant bacterial infection management were surveyed on epidemiology, disease, testing and management of MBL-producing Enterobacterales infections. Consensus statements were based on survey responses and reviewed by the panel for endorsement or revisions to achieve consensus during a virtual meeting.

RESULTS: All panellists acknowledged MBL-producing Enterobacterales as a key source of antimicrobial resistance and infection in most countries. All agreed these infections have high morbidity and mortality, leading to the need for critical-level care, longer hospital stays and significant healthcare costs. The negative clinical and economic consequences of MBL-producing Enterobacterales are compounded by inappropriate use of multidrug antimicrobial regimens. Therefore, a specific MBL-targeting agent is considered desirable. When aztreonam-avibactam and cefiderocol are available, the preferred first-line treatment is aztreonam-avibactam, per in vitro data showing aztreonam-avibactam activity against >90% of New Delhi MBL-producing Enterobacterales. If aztreonam-avibactam or cefiderocol are unavailable, treatment options are limited to co-administration of antimicrobials. Regional differences made it difficult to achieve unanimous consensus across all survey questions due to differences in patient factors, local epidemiology and testing availability.

CONCLUSIONS: The Delphi panel reached consensus on optimal management of MBL-producing Enterobacterales, confirming need for targeted MBL treatment, with monotherapy preferred where available.