Impact of extended-spectrum chromosomal AmpC (ESAC) of Escherichia coli on susceptibility to cefiderocol

Abstract

ABSTRACT The impact of chromosomally encoded wild-type or extended-spectrum (ESAC) AmpC β-lactamases of Escherichia coli on susceptibility to ceftazidime, cefepime, and cefiderocol was evaluated in different genetic backgrounds, including wild-type, PBP3-modified, and porin-deficient E. coli strains. Recombinant E. coli strains possessing the different backgrounds and producing variable ESACs were evaluated. Although ESAC enzymes conferred resistance to ceftazidime and decreased susceptibility to cefepime as expected, we showed here that cefiderocol was also a substrate of ESAC enzymes.IMPORTANCEWe showed here that chromosomally encoded intrinsic extended-spectrum cephalosporinases of Escherichia coli may impact susceptibility not only to ceftazidime and cefepime but also to cefiderocol.

Keywords

• AmpC
• Escherichia coli
• ESAC
• cefiderocol