The Evolving AMR Landscape and Updates for ESBL- and AmpC-Producing Enterobacterales

The Infectious Diseases Society of America (IDSA) published its 2026 Guidance on the Treatment of Antimicrobial Resistant Gram-Negative Infections on July 30, replacing earlier versions of the document. The update offers treatment suggestions for ESBL-producing Enterobacterales, AmpC-producing Enterobacterales, carbapenem-resistant Enterobacterales (CRE), difficult-to-treat resistant Pseudomonas aeruginosa, carbapenem-resistant Acinetobacter baumannii (CRAB), and Stenotrophomonas maltophilia.

Contagion has developed a new short series discussing the findings of the guidelines. Two guidance authors join this peer-to-peer discussion: Emily L. Heil, PharmD, MS, FIDP, BCIDP, AAHIVP, professor in the Department of Practice, Sciences, and Health Outcomes Research at the University of Maryland School of Pharmacy and pharmacy director of the Antimicrobial Stewardship Program at the University of Maryland Medical Center, and Pranita D. Tamma, MD, MHS, of the Department of Pediatrics at the University of Pennsylvania School of Medicine, the guidance’s corresponding author.

In this first episode, Heil and Tamma discuss the spread of NDM carbapenemases, gaps in rapid diagnostics outside the bloodstream, and the ESBL and AmpC updates. These include new oral agents for uncomplicated UTI (gepotidacin, pivmecillinam, and sulopenem), an expanded role for cefepime-enmetazobactam, piperacillin-tazobactam as an alternative for complicated UTI, and the addition of Hafnia alvei as a moderate-risk AmpC organism.