Activity of novel ceftibuten-avibactam, ceftazidime-avibactam, and comparators against a challenge set of Enterobacterales from outpatient centers and nursing homes across the United States (2022–2024)

Abstract

Ceftibuten is being developed in combination with the oral prodrug of avibactam. Outpatient isolates (n = 500) from 11 US states underwent susceptibility testing with manual broth microdilution. Ceftibuten had susceptibility rates of 64% (CLSI) and 23% (EUCAST). Ceftibuten-avibactam achieved 96.4% inhibition at MIC ≤ 1 µg/mL. Susceptibility rates were as follows: cefpodoxime (2.6%), ceftriaxone (1%), ceftazidime-avibactam (99.6%), tebipenem (89%), ertapenem (94.4%), levofloxacin (26.6%), trimethoprim-sulfamethoxazole (40.2%), and fosfomycin (96.8%). Ceftibuten-avibactam demonstrates potent in vitro activity against cephalosporin non-susceptible isolates.