LOOT, Céline; MILLOT, Gael; RICHARD, Egill; VIT, Claire; DARRACQ, Baptiste; PARISSI, Vincent; LEMOINE, Frédéric; NIAULT, Théophile; CURY, Jean; ROCHA, Eduardo; MAZEL, Didier

doi:10.1101/2022.09.11.507474

Langue

Document de travail - Pré-publication

Résumé en anglais

Integrons are genetic elements found exclusively in bacteria. They are well known for their role in disseminating antibiotic resistance genes among pathogens and more generally for enabling bacteria to rapidly adapt to changing environmental conditions. Integrons constitute a natural system to capture, stockpile, shuffle, express and disseminate genes embedded in cassettes. All these events are governed by the integron integrase through site-specific recombination between integron att sites (attC and attI sites). Here, we demonstrate that integron integrase can efficiently catalyze the insertion of cassettes in bacterial genomes, outside the att sites carried by the integron system. Surprisingly, analysis of more than 5 × 10 to the power of 5 independent clones revealed that the genome recombination sites differ greatly, in terms of sequence and structure, from both classical attC and attI recombination sites. We named theses new sites attG. Notably, among these a few are driving integration at very high rates. We also showed that, once inserted in genomes, cassettes can be expressed if located near a bacterial promoter. Moreover, even if occurring at low frequency, genome inserted cassettes can be excised precisely or imprecisely, inducing in this latter case, chromosomal modifications. These results unveil a new route for antibiotic resistance dissemination and expand the role of integrons in bacterial genome evolution.< Réduire

Mots clés en anglais

Bacterial evolution

antibiotic resistance

site-specific recombination

Integron

cassette dynamics

attC sites

genome-wide mapping

URI

https://oskar-bordeaux.fr/handle/20.500.12278/182187

DOI

http://dx.doi.org/10.1101/2022.09.11.507474

Project ANR

Etude de l'impact des intégrons chromosiques sur l'évolution des bactéries - ANR-21-CE12-0002
Integrative Biology of Emerging Infectious Diseases - ANR-10-LABX-0062

Unités de recherche

MFP (Laboratoire Microbiologie Fondamentale et Pathogénicité) - UMR 5234

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A new route for integron cassette dissemination among bacterial genomes

Langue

Résumé en anglais

Mots clés en anglais

URI

DOI

Project ANR

Unités de recherche