Cross-resistance to cefiderocol and ceftazidime–avibactam in KPC β-lactamase mutants and the inoculum effect

Abstract

We observed that most of the CZA-resistant KPC variants have a possible impact on cefiderocol by increasing the cefiderocol MICs. In addition, cefiderocol is greatly impacted by the inoculum effect, suggesting that precautions should be taken when treating infections with a suspected high inoculum.