Heterogeneous hydrolytic features for OXA-48-like β-lactamases.
- Oueslati S INSERM U914 'Emerging Resistance to Antibiotics', K.-Bicêtre, France LabEx LERMIT, Faculté de Médecine Paris Sud, K.-Bicêtre, France.
- Nordmann P INSERM U914 'Emerging Resistance to Antibiotics', K.-Bicêtre, France LabEx LERMIT, Faculté de Médecine Paris Sud, K.-Bicêtre, France Centre National Associé-Centre de Référence des Résistances aux Antibiotiques, K.-Bicêtre, France Medical and Molecular Microbiology, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland HFR-Hôpital Cantonal, Fribourg, Switzerland.
- Poirel L INSERM U914 'Emerging Resistance to Antibiotics', K.-Bicêtre, France LabEx LERMIT, Faculté de Médecine Paris Sud, K.-Bicêtre, France Centre National Associé-Centre de Référence des Résistances aux Antibiotiques, K.-Bicêtre, France Medical and Molecular Microbiology, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland laurent.poirel@unifr.ch.
- 2015-01-14
Published in:
- The Journal of antimicrobial chemotherapy. - 2015
carbapenemases
class D β-lactamases
enzymatic activity
Chromatography, Ion Exchange
Cloning, Molecular
Enterobacteriaceae
Gene Expression
Hydrolysis
Kinetics
Microbial Sensitivity Tests
Recombinant Proteins
Spectrophotometry, Ultraviolet
beta-Lactamases
beta-Lactams
English
OBJECTIVES
Carbapenem-hydrolysing class D β-lactamases of the OXA-48 type are increasingly reported from Enterobacteriaceae. β-Lactamase OXA-48 hydrolyses penicillins very efficiently, but carbapenems only weakly and spares broad-spectrum cephalosporins. Recently, diverse OXA-48-like β-lactamases have been identified worldwide (OXA-162, OXA-181, OXA-163, OXA-204 and OXA-232). They differ by few amino acid substitutions or by amino acid deletions.
METHODS
blaOXA-48, blaOXA-162, blaOXA-163, blaOXA-181, blaOXA-204 and blaOXA-232 were cloned into the same expression vector and expressed in the same Escherichia coli background. Kinetic studies were performed with enzymes purified by ion-exchange chromatography. Determination of hydrolytic activities was performed by UV spectrophotometry. MICs were determined for all recombinant strains, using as background either the WT E. coli TOP10 strain or a porin-deficient E. coli strain.
RESULTS
Kinetic studies showed that OXA-162 and OXA-204 shared the same hydrolytic properties as OXA-48. On the other hand, OXA-181 possessed a higher ability to hydrolyse carbapenems, while OXA-232 hydrolysed those substrates less efficiently. In contrast to the other OXA-48-like β-lactamases, OXA-163 hydrolysed broad-spectrum cephalosporins very efficiently, but did not possess significant carbapenemase activity. Although several of these OXA-48-like enzymes possess low activity against carbapenems, MICs of carbapenems were significantly elevated when determined for strains possessing permeability defects.
CONCLUSIONS
A detailed comparative analysis of the kinetic properties of the OXA-48-like β-lactamases is provided here. It clarifies the respective features of each OXA-48-like variant and their respective impacts in terms of carbapenem resistance.
Carbapenem-hydrolysing class D β-lactamases of the OXA-48 type are increasingly reported from Enterobacteriaceae. β-Lactamase OXA-48 hydrolyses penicillins very efficiently, but carbapenems only weakly and spares broad-spectrum cephalosporins. Recently, diverse OXA-48-like β-lactamases have been identified worldwide (OXA-162, OXA-181, OXA-163, OXA-204 and OXA-232). They differ by few amino acid substitutions or by amino acid deletions.
METHODS
blaOXA-48, blaOXA-162, blaOXA-163, blaOXA-181, blaOXA-204 and blaOXA-232 were cloned into the same expression vector and expressed in the same Escherichia coli background. Kinetic studies were performed with enzymes purified by ion-exchange chromatography. Determination of hydrolytic activities was performed by UV spectrophotometry. MICs were determined for all recombinant strains, using as background either the WT E. coli TOP10 strain or a porin-deficient E. coli strain.
RESULTS
Kinetic studies showed that OXA-162 and OXA-204 shared the same hydrolytic properties as OXA-48. On the other hand, OXA-181 possessed a higher ability to hydrolyse carbapenems, while OXA-232 hydrolysed those substrates less efficiently. In contrast to the other OXA-48-like β-lactamases, OXA-163 hydrolysed broad-spectrum cephalosporins very efficiently, but did not possess significant carbapenemase activity. Although several of these OXA-48-like enzymes possess low activity against carbapenems, MICs of carbapenems were significantly elevated when determined for strains possessing permeability defects.
CONCLUSIONS
A detailed comparative analysis of the kinetic properties of the OXA-48-like β-lactamases is provided here. It clarifies the respective features of each OXA-48-like variant and their respective impacts in terms of carbapenem resistance.
- Language
-
- English
- Open access status
- bronze
- Identifiers
-
- DOI 10.1093/jac/dku524
- PMID 25583748
- Persistent URL
- https://sonar.ch/global/documents/136814
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