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Updated: Mar 20, 2026
12:32
Quantification of Plasmid-Mediated Antibiotic Resistance in an Experimental Evolution Approach
Published on: December 14, 2019
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Spread of Plasmids Carrying Multiple GES Variants.
Gaelle Cuzon1, Pierre Bogaerts2, Caroline Bauraing2
1Bactériologie-Hygiene Unit, APHP, Bicêtre Hospital, Le Kremlin-Bicêtre, France Université Paris Sud, Université Paris Saclay, LabEx Lermit, Faculty of Medicine, Le Kremlin-Bicetre, France French National Reference Center for Antibiotic Resistance: Carbapenemase-Producing Enterobacteriaceae, Le Kremlin-Bicêtre, France.
Antimicrobial Agents and Chemotherapy
|May 25, 2016
Summary
This study identified five Enterobacteriaceae isolates with two GES beta-lactamase variants, including a carbapenemase. These findings highlight the in vivo spread of antibiotic resistance genes on plasmids.
Area of Science:
- Microbiology
- Molecular Biology
- Infectious Diseases
Background:
- Extended-spectrum β-lactamase (ESBL) and carbapenemase production in Enterobacteriaceae are significant public health concerns.
- The GES enzyme family includes variants with diverse hydrolytic activities against β-lactam antibiotics.
Purpose of the Study:
- To characterize Enterobacteriaceae isolates producing two GES variants with extended-spectrum β-lactamase (ESBL) and carbapenemase activities.
- To investigate the genetic context and dissemination mechanisms of these resistance genes.
Main Methods:
- Phenotypic detection of ESBL production.
- Identification of GES variants using molecular methods.
- Whole-genome sequencing of isolates.
- Plasmid analysis, including size and conjugation.
Main Results:
- Five Enterobacteriaceae isolates harbored both GES-7 ESBL and GES-6 carbapenemase variants.
- Both GES alleles were located on the same integron within an 80-kb IncM1 self-conjugative plasmid.
- Whole-genome sequencing indicated horizontal gene transfer of the plasmid and clonal spread of Enterobacter cloacae.
Conclusions:
- This is the first report in Europe of Enterobacteriaceae isolates co-carrying two GES β-lactamases, one with carbapenem-hydrolyzing activity.
- The findings underscore the role of self-conjugative plasmids in the in vivo dissemination of multidrug resistance genes.
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