Integrase-mediated recombination of the bel-1 gene cassette encoding the extended-spectrum β-lactamase BEL-1

Bouheraoua, Nacim; Poirel, Laurent; Bourreau, Baptiste; Bonnin, Rémy; Laroche, Laurent; Naas, Thierry; Nordmann, Patrice

doi:10.1128/AAC.00030-18

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Journal article

Integrase-mediated recombination of the bel-1 gene cassette encoding the extended-spectrum β-lactamase BEL-1

Bouheraoua, Nacim Quinze-Vingts National Ophthalmology Hospital, UPMC-Sorbonne Universities, Paris, France
Poirel, Laurent Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, 3INSERM European Unit (IAME, France), University of Fribourg, Switzerland - Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), University of Fribourg, Switzerland
Bourreau, Baptiste EA7361, Université Paris-Sud, Université Paris-Saclay, LabEx Lermit, Bacteriology-Hygiene unit, APHP, Hôpital Bicêtre, Le Kremlin-Bicêtre, France - EERA ?Evolution and Ecology of Resistance to Antibiotics? Unit, Institut Pasteur-APHP-Université Paris Sud, Paris, France - Associated French National Reference Center for Antibiotic Resistance ?Carbapenemase-producing Enterobacteriaceae?, University of Lausanne, Switzerland
Bonnin, Rémy Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, 3INSERM European Unit (IAME, France), University of Fribourg, Switzerland - Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), University of Fribourg, Switzerland
Laroche, Laurent Quinze-Vingts National Ophthalmology Hospital, UPMC-Sorbonne Universities, Paris, France
Naas, Thierry EA7361, Université Paris-Sud, Université Paris-Saclay, LabEx Lermit, Bacteriology-Hygiene unit, APHP, Hôpital Bicêtre, Le Kremlin-Bicêtre, France - EERA ?Evolution and Ecology of Resistance to Antibiotics? Unit, Institut Pasteur-APHP-Université Paris Sud, Paris, France - Associated French National Reference Center for Antibiotic Resistance ?Carbapenemase-producing Enterobacteriaceae?, University of Lausanne, Switzerland
Nordmann, Patrice Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, 3INSERM European Unit (IAME, France), University of Fribourg, Switzerland - Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), University of Fribourg, Switzerland - Institute for Microbiology, University of Lausanne and University Hospital Centre, Lausanne, Switzerland

26.02.2018

Published in:

Antimicrobial Agents and Chemotherapy. - 2018, p. AAC.00030-18

English Integrons are genetic elements that can acquire and rearrange gene cassettes. The blaBEL-1 gene encodes an extended-spectrum β-lactamase, BEL-1, that is present at second position of the variable region of class 1 integrons identified in Pseudomonas aeruginosa. The mobility of the bel-1 gene cassette was analyzed in physiological conditions and with the integrase gene being overexpressed. Cassette mobility in Escherichia coli was detected by excision/integration into the recipient integron In3 on the conjugative plasmid R388, with the over-produced integrase. Despite several antibiotic pressures, the bel-1 cassette remained at the second position in the integron, highlighting its stability in P. aeruginosa. Overexpression of the integrase gene in E. coli induced the bel-1 cassette recombination. However, cassettes containing two genes (blaBEL-1/smr2 or blaBEL-1/aacA4) were excised suggesting that the bel-1 cassette attC site was defective. We showed that bel-1 is a stable gene cassette under physiological growth conditions irrespective of the selective antibiotic pressure, that may be mobilized upon over-overexpression of the integrase gene.

Faculty

Faculté des sciences et de médecine

Department

Médecine 3ème année

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