Identification of extended-spectrum, AmpC, and carbapenem- hydrolyzing beta-lactamases in Escherichia coli and Klebsiella pneumoniae by disk tests

Abstract

Antibiotic disks with and without clavulanic acid, 3-aminophenylboronic acid, or EDTA were tested with a set of 55 Klebsiella pneumoniae and Escherichia coli strains producing well-characterized extended-spectrum, AmpC, or carbapenem-hydrolyzing beta-lactamases. A relatively simple scheme was devised for distinguishing beta-lactamase types in clinical isolates with or without intact outer membrane porins.