Kinetic Properties of Four Plasmid-Mediated AmpC β-Lactamases
Open Access
- 1 October 2005
- journal article
- research article
- Published by American Society for Microbiology in Antimicrobial Agents and Chemotherapy
- Vol. 49 (10) , 4240-4246
- https://doi.org/10.1128/aac.49.10.4240-4246.2005
Abstract
The heterologous production in Escherichia coli , the purification, and the kinetic characterization of four plasmid-encoded class C β-lactamases (ACT-1, MIR-1, CMY-2, and CMY-1) were performed. Except for their instability, these enzymes are very similar to the known chromosomally encoded AmpC β-lactamases. Their kinetic parameters did not show major differences from those obtained for the corresponding chromosomal enzymes. However, the K m values of CMY-2 for cefuroxime, cefotaxime, and oxacillin were significantly decreased compared to those of the chromosomal AmpC enzymes. Finally, the susceptibility patterns of different E. coli hosts producing a plasmid- or a chromosome-encoded class C enzyme toward β-lactam antibiotics are mainly due to the overproduction of the β-lactamase in the periplasmic space of the bacteria rather than to a specific catalytic profile of the plasmid-encoded β-lactamases.Keywords
This publication has 22 references indexed in Scilit:
- Increase in ampC promoter strength due to mutations and deletion of the attenuator in a clinical isolate of cefoxitin-resistant Escherichia coli as determined by RT–PCRJournal of Antimicrobial Chemotherapy, 2005
- Extended Spectrum ??-Lactamase (ESBL)-Producing EnterobacteriaceaeDrugs, 2003
- EnvZ-OmpR Interaction and Osmoregulation in Escherichia coliJournal of Biological Chemistry, 2002
- Plasmid-Determined AmpC-Type β-LactamasesAntimicrobial Agents and Chemotherapy, 2002
- Structure of the Extended-Spectrum Class C β-Lactamase of Enterobacter cloacae GC1, a Natural Mutant with a Tandem Tripeptide Insertion,Biochemistry, 1999
- The β-lactamase cycle: a tale of selective pressure and bacterial ingenuityNatural Product Reports, 1999
- When drug inactivation renders the target irrelevant to antibiotic resistance: a case story with β‐lactamsMolecular Microbiology, 1999
- Beta‐lactamases and bacterial resistance to antibioticsMolecular Microbiology, 1995
- Sensitivity of Escherichia coli to various β‐lactams is determined by the interplay of outer membrane permeability and degradation by periplasmic β‐lactamases: a quantitative predictive treatmentMolecular Microbiology, 1987
- Role of permeability barriers in resistance to β-lactam antibioticsPharmacology & Therapeutics, 1985