Current Antibiotic Options for the Treatment of Infections with AmpC-Producing Enterobacterales.

AmpC β-lactamases, found in certain Enterobacterales, confer resistance to third-generation cephalosporins, some β-lactam/β-lactamase inhibitor combinations, and cephamycins. They may be chromosomal or plasmid-mediated. Generally, third-generation cephalosporins are avoided in the treatment of high-risk AmpC producers, with cefepime or carbapenems being preferred for severe infections. Non-β-lactam options (fluoroquinolones, trimethoprim-sulfamethoxazole, and aminoglycosides) remain viable options if they test susceptible. New β-lactam/β-lactamase inhibitors and cefiderocol retain activity against AmpC, but are generally reserved for situations where AmpC coexists with carbapenemases. Optimal therapy remains unclear and should be informed by well-designed prospective studies or randomized controlled trials.