Tackling the increasing threat of MBL-producing...

Antimicrobial resistance (AMR) continues to challenge healthcare systems worldwide, with carbapenem-resistant Gram-negative infections among the most urgent clinical threats. At a symposium held during ESCMID Global 2026, Dr Subramanian Swaminathan (India), Dr Paula Ramírez (Spain), Prof Gian Maria Rossolini (Italy), Prof Garyfallia Poulakou (Greece), and Prof Michele Bartoletti (Italy) explored the epidemiology, diagnosis, and management of infections caused by metallo-β-lactamase (MBL)-producing organisms, with a particular focus on carbapenem-resistant Enterobacterales (CRE) and Stenotrophomonas maltophilia.

MBL-producing pathogens: A growing global challenge

Dr Swaminathan highlighted the growing global impact of carbapenem-resistant Gram-negative infections. He noted that MBL-producing CRE are increasingly reported worldwide, particularly in the Asia-Pacific region, the Middle East, Africa, and Latin America, with the New Delhi MBL (NDM-1) emerging as the dominant MBL in many regions (Figure 1). [J Glob Antimicrob Resist 2024;37:168-175; ATLAS (Antimicrobial Testing Leadership and Surveillance. https:// atlas-surveillance.com. Accessed April 2026]

The clinical consequences are substantial. Infections caused by MBL-producing organisms are associated with increased mortality, prolonged hospitalisation, higher healthcare costs, and greater utilisation of intensive care resources. [Open Forum Infect Dis 2018; 5:ofy150; Antibiotics 2022;11:694] Studies showed significantly increased mortality among patients infected with MBL-producing pathogens than those infected with susceptible organisms. [PLoS One 2016;10:e0123337; Antimicrob Agents Chemother 2009;53:1868-1873; J Antimicrob Chemother 2020;75:697-708]

Prof Rossolini described MBL-producing CRE as “an increasing global challenge”. The ability of MBL genes to spread via mobile genetic elements further accelerates their dissemination across healthcare settings and geographical regions. [J Glob Antimicrob Resist 2024;36:123-131; Infect Dis Ther 2024;13:2423-2447]

Importantly, MBL-producing pathogens remain particularly difficult to treat because currently available β-lactamase inhibitors do not directly inhibit MBL enzymes. As a result, therapeutic options remain more limited than for infections caused by serine carbapenemases, such as KPC and OXA-48-like producers.

Resources

Tackling the increasing threat of MBL-producing pathogens and S. maltophilia: Key insights from ESCMID Global 2026