mPseudomonas aeruginosa isolates defective in function of the LasR quorum sensing regulator are frequent in diverse environmental niches

Groleau, Marie-Christine; Taillefer, Hélène; Vincent, Antony T.; Constant, Philippe ORCID: https://orcid.org/0000-0003-2739-2801 et Déziel, Éric ORCID: https://orcid.org/0000-0002-4609-0115 (2021). mPseudomonas aeruginosa isolates defective in function of the LasR quorum sensing regulator are frequent in diverse environmental niches Environmental microbiology , vol. 24 , nº 3. pp. 1062-1075. DOI: 10.1111/1462-2920.15745.

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Résumé

The saprophyte Pseudomonas aeruginosa is a versatile opportunistic pathogen causing infections in immunocompromised individuals. To facilitate its adaptation to a large variety of niches, this bacterium exploits population density-dependent gene regulation systems called quorum sensing (QS). In P. aeruginosa, three distinct but interrelated QS systems (las, rhl and pqs) regulate the production of many survival and virulence functions. In prototypical strains, the las system, through its transcriptional regulator LasR, is important for the full activation of the rhl and pqs systems. Still, LasR-deficient isolates have been reported, mostly sampled from the lungs of people with cystic fibrosis, where they are considered selected by the chronic infection environment. In this study, we show that a defect in LasR activity appears to be an actually widespread mechanism of adaptation in this bacterium. Indeed, we found abundant LasR-defective isolates sampled from hydrocarbon-contaminated soils, hospital sink drains and meat/fish market environments, using an approach based on phenotypic profiling, supported by gene sequencing. Interestingly, several LasR-defective isolates maintain an active rhl system or are deficient in pqs system signalling. The high prevalence of a LasR-defective phenotype among environmental P. aeruginosa isolates questions the role of QS in niche adaptation.

Type de document:	Article
Mots-clés libres:	=
Centre:	Centre INRS-Institut Armand Frappier
Date de dépôt:	22 juin 2022 19:32
Dernière modification:	31 déc. 2023 05:00
URI:	https://espace.inrs.ca/id/eprint/12341

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