Chequerboard titration of cephalosporin CXA-101 (FR264205) and tazobactam versus -lactamase-producing Enterobacteriaceae

BackgroundThe developmental oxyimino-cephalosporin CXA-101 (FR264205) is notable for having greater antipseudomonal activity than ceftazidime. It is active against Enterobacteriaceae too, but is compromised by extended-spectrum, AmpC and carbapenem-hydrolysing β-lactamases. We investigated the tazobactam concentrations needed to potentiate this cephalosporin against strains with these mechanisms.