Comparative activity of ceftibuten combinations with avibactam, ledaborbactam, and xeruborbactam against recombinant β-lactamase-producing Escherichia coli and contemporary WGS-characterized strains of carbapenemase-producing Enterobacterales

We evaluated the activity of ceftibuten combinations with avibactam, ledaborbactam, and xeruborbactam against isogenic Escherichia coli and clinical Enterobacterales isolates producing broad-spectrum β-lactamases. Avibactam and ledaborbactam enhanced ceftibuten activity against transformants producing serine-β-lactamases. Ceftibuten/xeruborbactam was also active against VIM and some IMP producers. All combinations were active against OXA-48- and KPC-producing clinical isolates. Ceftibuten/xeruborbactam also retained activity against VIM-producing clinical strains. Susceptibility rates for MBL producers varied, depending on the CLSI or EUCAST breakpoints applied.