Thomas Clamens

Université de Rouen Normandie

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Olivier Lesouhaitier

Normandie Université

Sylvie Chevalier

Université de Rouen Normandie

Emeline Bouffartigues

Université de Rouen Normandie

Marc Feuilloley

Université de Rouen Normandie

Alain Dufour

Laboratoire de Biotechnologie et Chimie Marines

Thibaut Rosay

The University of Texas Southwestern Medical Center

Ali Tahrioui

Université de Rouen Normandie

Florie Desriac

Normandie Université

Alexis Bazire

Institut Universitaire Européen de la Mer

Julien Vieillard

Institut National des Sciences Appliquées Rouen Normandie

Cooperative Institutions

Université de Rouen Normandie

Normandie Université

Centre National de la Recherche Scientifique

Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail

Inserm

Institut National des Sciences Appliquées Rouen Normandie

Laboratoire COBRA

Université de Caen Normandie

Génétique Moléculaire Génomique Microbiologie

Communication Bactérienne et Stratégie Anti-infectieuses

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Development of a novel functional core-shell-shell nanoparticles: From design to anti-bacterial applications

Journal of Colloid and Interface Science (2017)

Nabil Bouazizi R. Bargougui Pascal Thébault Thomas Clamens Florie Desriac

Triethoxysilane

Surface Modification

Zeta potential

10.1016/j.jcis.2017.11.074

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Citations (16)

The involvement of the ami operon in Pseudomonas aeruginosa virulence regulation and biofilm formation reveals new functions for the amidase AmiE

HAL (Le Centre pour la Communication Scientifique Directe) (2017)

Thomas Clamens Florie Desriac Thibaut Rosay Alexandre Crépin Alain Dufour

We have previously shown that the C-type Natriuretic Peptide (CNP), a peptide produced by the lung, prevents Pseudomonas aeruginosa biofilm formation. In the present study, we identified AmiC as the bacterial target explaining CNP effects, and we studied the involvement of the aliphatic amidase AmiE in these effects. Comparison of 3D structures of human natriuretic peptide receptors and Pseudomonas proteins revealed that the bacterial protein AmiC shows significant similarity with the human C-type natriuretic peptide receptor (hNPR-C). Recombinant protein AmiC was purified and protein/peptide interactions assessed using MicroScale Thermophoresis. Results showed that both CNP and hNPR-C agonists bind the AmiC protein. The amiC gene belongs to the ami operon. This operon also encodes the aliphatic amidase AmiE which hydrolyses short-chain aliphatic amides to their corresponding organic acids. We investigated AmiE potential alternative functions in P. aeruginosa. We observed that over expression of AmiE protein altered biofilm formation, bacterial motilities and quorum sensing molecules production. Using several infection models, we demonstrated that AmiE overproduction led to a strong decrease in P. aeruginosa virulence both in vitro and in vivo, suggesting that in addition to its carbon-nitrogen metabolic process activities, AmiE would have multiple other functions. We demonstrate that the bacterial protein AmiC is an ortholog of the eukaryotic receptor hNPR-C, acting as a CNP sensor in P. aeruginosa. Our data show that the whole ami operon has new functions in bacteria, allowing to modulate the switch between chronic and acute infection depending on exposition to host factors.

Amidase

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Study of key RNA metabolism proteins inEnterococcus faecalis

RNA Biology (2020)

Marine Salze Cécile Muller Benoı̂t Bernay Axel Hartke Thomas Clamens

The control of mRNA turnover is essential in bacteria to allow rapid adaptation, especially in opportunistic pathogen like Enterococcus faecalis. This mechanism involves RNase and DEAD-box helicases that are key elements in RNA processing and their associations form the degradosome with accessory proteins. In this study, we investigated the function of four RNases (J1, J2, Y and III) and three DEAD-box helicases (CshA, CshB, CshC) present in most Enterococci. The interactions of all these RNA metabolism actors were investigated in vitro, and the results are in accordance with a degradosome structure close to the one of Bacillus subtilis. At the physiological level, we showed that RNase J1 is essential, whereas RNases J2 and III have a role in cold, oxidative and bile salts stress response, and RNase Y in general fitness. Furthermore, RNases J2, Y and III mutants are affected in virulence in the Galleria mellonella infection model. Concerning DEAD-box helicases, all of them are involved in cold shock response. Since the ΔcshA mutant was the most stress impacted strain, we studied this DEAD-box helicase CshA in more detail. This showed that CshA autoregulates its own expression by binding to its mRNA 5ʹUnstranslated Region. Interestingly, CshC is also involved in the expression control of CshA by a hitherto unprecedented mechanism.

Degradosome

Enterococcus faecalis

RNA Helicase A

Cold-shock domain

10.1080/15476286.2020.1728103

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Citations (14)

Le « C-type Natriuretic Peptide » (CNP) comme arme dans la lutte contre les biofilms de Pseudomonas aeruginosa : Présentation du mécanisme d’action

HAL (Le Centre pour la Communication Scientifique Directe) (2016)

Thomas Clamens Takfarinas Kentache Julie Hardouin Pascal Cosette Alexis Bazire

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The absence of SigX results in impaired carbon metabolism and membrane fluidity in Pseudomonas aeruginosa

Scientific Reports (2018)

Maud Fléchard Rachel Duchesne Ali Tahrioui Emeline Bouffartigues Ségolène Depayras

Abstract In Pseudomonas aeruginosa , SigX is an extra-cytoplasmic function σ factor that belongs to the cell wall stress response network. In previous studies, we made the puzzling observation that sigX mutant growth was severely affected in rich lysogeny broth (LB) but not in minimal medium. Here, through comparative transcriptomic and proteomic analysis, we show that the absence of SigX results in dysregulation of genes, whose products are mainly involved in transport, carbon and energy metabolisms. Production of most of these genes is controlled by carbon catabolite repression (CCR), a key regulatory system than ensures preferential carbon source uptake and utilization, substrate prioritization and metabolism. The strong CCR response elicited in LB was lowered in a sigX mutant, suggesting altered nutrient uptake. Since the absence of SigX affects membrane composition and fluidity, we suspected membrane changes to cause such phenotype. The detergent polysorbate 80 (PS80) can moderately destabilize the envelope resulting in non-specific increased nutrient intake. Remarkably, growth, membrane fluidity and expression of dysregulated genes in the sigX mutant strain were restored in LB supplemented with PS80. Altogether, these data suggest that SigX is indirectly involved in CCR regulation, possibly via its effects on membrane integrity and fluidity.

10.1038/s41598-018-35503-3

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Citations (24)

Relationships between Pf4 phage, biofilm and virulence in Pseudomonas aeruginosa.

HAL (Le Centre pour la Communication Scientifique Directe) (2018)

Damien Tortuel Ali Tahrioui Co. Azuama Sophie Rodrigues Thomas Clamens

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The aliphatic amidase AmiE is involved in regulation of Pseudomonas aeruginosa virulence

Scientific Reports (2017)

Thomas Clamens Thibaut Rosay Alexandre Crépin Teddy Grandjean Takfarinas Kentache

Abstract We have previously shown that the eukaryotic C-type natriuretic peptide hormone (CNP) regulates Pseudomonas aeruginosa virulence and biofilm formation after binding on the AmiC sensor, triggering the amiE transcription. Herein, the involvement of the aliphatic amidase AmiE in P. aeruginosa virulence regulation has been investigated. The proteome analysis of an AmiE over-producing strain (AmiE + ) revealed an expression change for 138 proteins, including some that are involved in motility, synthesis of quorum sensing compounds and virulence regulation. We observed that the AmiE + strain produced less biofilm compared to the wild type, and over-produced rhamnolipids. In the same line, AmiE is involved in P. aeruginosa motilities (swarming and twitching) and production of the quorum sensing molecules N -acyl homoserine lactones and Pseudomonas Quinolone Signal (PQS). We observed that AmiE overproduction reduced levels of HCN and pyocyanin causing a decreased virulence in different hosts (i.e. Dictyostelium discoideum and Caenorhabditis elegans ). This phenotype was further confirmed in a mouse model of acute lung infection, in which AmiE overproduction resulted in an almost fully virulence decrease. Taken together, our data suggest that, in addition to its role in bacterial secondary metabolism, AmiE is involved in P. aeruginosa virulence regulation by modulating pilus synthesis and cell-to-cell communication.

Pyocyanin

Swarming motility

Amidase

10.1038/srep41178

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Citations (30)

The hormone C-type natriuretic peptide (CNP) effects on P. aeruginosa: a new natural weapon against biofilm formation

HAL (Le Centre pour la Communication Scientifique Directe) (2019)

Mélissande Louis Thomas Clamens Sophie Rodrigues Ali Tahrioui F. Desriac

NPR2

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Nouvelles fonctions pour les produits de l’opéron ami de Pseudomonas aeruginosa: Régulation de la virulence et du biofilm bactérien.

HAL (Le Centre pour la Communication Scientifique Directe) (2017)

Thomas Clamens Thibaut Rosay Teddy Grandjean Julie Hardouin Pascal Cosette

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Silver nanoparticle embedded copper oxide as an efficient core–shell for the catalytic reduction of 4-nitrophenol and antibacterial activity improvement

Dalton Transactions (2018)

Nabil Bouazizi Julien Vieillard Pascal Thébault Florie Desriac Thomas Clamens

A facile and eco-friendly method was developed to prepare a microporous CuO@Ag0 core-shell with high catalytic and antibacterial activities. Scanning and transmission electron microscopy revealed a preponderance of nearly spherical 50 nm particles with slight structure compaction. Comparison of the hysteresis loops confirmed the structure compaction after AgNP incorporation, and a significant decrease of the specific surface area from 55.31 m2 g-1 for CuO to 8.03 m2 g-1 for CuO@Ag0 was noticed. A kinetic study of 4-nitrophenol (4-NP) reduction into 4-aminophenol (4-AP) with sodium borohydride revealed a first order reaction that produces total conversion in less than 18 minutes. CuO@Ag0 also exhibited appreciable antibacterial activity against Staphylococcus aureus. The antibacterial effects were found to strongly depend on the size, contact surface, morphology and chemical composition of the catalyst particles. The addition of Ag0-NPs produced more reactive oxygen species in the bacteria medium. These results open promising prospects for its potential applications as a low cost catalyst in wastewater treatment and antibacterial agent in cosmetics.

4-Nitrophenol

Selective catalytic reduction

Nitrophenol

Copper oxide

10.1039/c8dt02154f

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Citations (61)