Cefiderocol Activity Against Clinical<i>Pseudomonas aeruginosa</i>Isolates Exhibiting Ceftolozane-Tazobactam Resistance

Abstract

Our findings suggest that alterations in the target binding sites of <i>P. aeruginosa</i>-derived AmpC β-lactamases have the potential to reduce the activity of 3 of 4 novel β-lactams (ie, ceftolozane-tazobactam, ceftazidime-avibactam, and cefiderocol) and potentially increase susceptibility to imipenem-relebactam. These findings are in need of validation in a larger cohort.