Sadek, Mustafa Juhas, Mario Poirel, Laurent Nordmann, Patrice 2020-11-17 Metallo-β-lactamase (MBL)-producing Escherichia coli isolates resistant to the newly developed β-lactam/β-lactamase inhibitor drug combination aztreonam-avibactam (ATM-AVI) have been reported. Here, we analyzed a series of 118 clinical MBL- producing E. coli isolates of various geographical origins for susceptibility to ATM-AVI. The nature of the PBP3 protein sequence and the occurrence of blaCMY genes for susceptibility to ATM-AVI were investigated. We showed here that elevated MICs of ATM-AVI among MBL-producing E. coli isolates resulted from a combination of different features, including modification of PBP3 protein sequence through specific amino acid insertions and production of CMY-type enzymes, particularly, CMY-42. We showed here that those insertions identified in the PBP3 sequence are not considered the unique basis of resistance to ATM-AVI, but they significantly contribute to it. application/pdf https://folia.unifr.ch/global/documents/309112 https://folia.unifr.ch/documents/309112/files/nor_gfl.pdf https://folia.unifr.ch/documents/309112/files/nor_gfl_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1128/AAC.01659-20 info:eu-repo/semantics/openAccess License undefined Antimicrobial Agents and Chemotherapy. - 2020, vol. 64, no. 12, p. 10.1128/aac.01659-20 info:eu-repo/classification/udc/57 Genetic features leading to reduced susceptibility to aztreonam-avibactam among metallo-β-lactamase-producing escherichia coli isolates http://purl.org/coar/resource_type/c_6501