Search

Your search keyword '"Laure Taupin"' showing total 33 results
Start Over Author "Laure Taupin"
33 results on '"Laure Taupin"'

1. Sensitivity of Legionella pneumophila to phthalates and their substitutes

Author

Alexandre Crépin, Audrey Thiroux, Aurélien Alafaci, Amine M. Boukerb, Izelenn Dufour, Eirini Chrysanthou, Joanne Bertaux, Ali Tahrioui, Alexis Bazire, Sophie Rodrigues, Laure Taupin, Marc Feuilloley, Alain Dufour, Jocelyne Caillon, Olivier Lesouhaitier, Sylvie Chevalier, Jean-Marc Berjeaud, and Julien Verdon

Subjects
Medicine, Science
Abstract

Abstract Phthalates constitute a family of anthropogenic chemicals developed to be used in the manufacture of plastics, solvents, and personal care products. Their dispersion and accumulation in many environments can occur at all stages of their use (from synthesis to recycling). However, many phthalates together with other accumulated engineered chemicals have been shown to interfere with hormone activities. These compounds are also in close contact with microorganisms that are free-living, in biofilms or in microbiota, within multicellular organisms. Herein, the activity of several phthalates and their substitutes were investigated on the opportunistic pathogen Legionella pneumophila, an aquatic microbe that can infect humans. Beside showing the toxicity of some phthalates, data suggested that Acetyl tributyl citrate (ATBC) and DBP (Di-n-butyl phthalate) at environmental doses (i.e. 10–6 M and 10–8 M) can modulate Legionella behavior in terms of motility, biofilm formation and response to antibiotics. A dose of 10–6 M mostly induced adverse effects for the bacteria, in contrast to a dose of 10–8 M. No perturbation of virulence towards Acanthamoeba castellanii was recorded. These behavioral alterations suggest that L. pneumophila is able to sense ATBC and DBP, in a cross-talk that either mimics the response to a native ligand, or dysregulates its physiology.

Published
2023
Full Text
View/download PDF

2. Identification of the quorum sensing signal of the opportunistic pathogen inducing bleaching disease in the red macroalga Halymenia floresii holobiont

Author

Shareen A Abdul Malik, Mahasweta Saha, Laure Taupin, Gilles Bedoux, Nathalie Bourgougnon, and Daniel Robledo

Subjects
Bleaching, Halymenia floresii, homoserine lactones, lambda-carrageenophyte, LC-MS, Quorum Sensing, Aquaculture. Fisheries. Angling, SH1-691, Environmental sciences, GE1-350
Abstract

Seaweed surface provides a suitable substratum for the settlement of microorganisms (bacteria, viruses, and plankton). These microbial partners may have either beneficial or detrimental effects on the host since surface microbiota can act either as a protective layer to the macroalgae (symbiotic beneficial relations) or, under changing environmental conditions, the microbial equilibrium may shift to a detrimental, pathogenic state thus inducing diseases in the host. In commercial aquaculture, seaweed diseases feature a growing concern. Pathogenicity of microorganisms that infect algal hosts is closely related to the release of virulence factors and the formation of biofilms, both of which are regulated by Quorum Sensing (QS). The main focus of this study is to determine the pathogenicity of the surface-associated bacteria of Halymenia floresii, a carrageenophyte that originated from distinct habitats. Twenty-five bacterial species isolated from the surface of H. floresii were individually tested for tip bleaching assay to evaluate their potential pathogenicity. Ten isolates significantly reduced the risk of tip bleaching in H. floresii and were designated as “significantly non-pathogenic”. Vibrio owensii was identified as a “significant pathogen” inducing bleaching disease in H. floresii. By using LC-MS, we here identified its HomoSerine Lactones (HSL) QS signal, as a C4-HSL (short-chain). This study thus suggests a possible involvement of QS signal (short-chain) in the disease-inducing bacterium from the aquaculture ponds (an integrated multitrophic aquaculture system). This study firstly reports on the surface-associated bacteria of a lambda-carrageenophyte. This study must contribute to the development of dedicated strategies for disease control based on HSL disruption in aquaculture.

Published
2022
Full Text
View/download PDF

3. Epinephrine affects motility, and increases adhesion, biofilm and virulence of Pseudomonas aeruginosa H103

Author

Mélyssa Cambronel, Damien Tortuel, Kelly Biaggini, Olivier Maillot, Laure Taupin, Karine Réhel, Isabelle Rincé, Cécile Muller, Julie Hardouin, Marc Feuilloley, Sophie Rodrigues, and Nathalie Connil

Subjects
Medicine, Science
Abstract

Abstract Microbial endocrinology has demonstrated for more than two decades, that eukaryotic substances (hormones, neurotransmitters, molecules of the immune system) can modulate the physiological behavior of bacteria. Among them, the hormones/neurotransmitters, epinephrine (Epi) and norepinephrine (NE), released in case of stress, physical effort or used in medical treatment, were shown to be able to modify biofilm formation in various bacterial species. In the present study, we have evaluated the effect of Epi on motility, adhesion, biofilm formation and virulence of Pseudomonas aeruginosa, a bacterium linked to many hospital-acquired infections, and responsible for chronic infection in immunocompromised patients including persons suffering from cystic fibrosis. The results showed that Epi increased adhesion and biofilm formation of P. aeruginosa, as well as its virulence towards the Galleria mellonella larvae in vivo model. Deciphering the sensor of this molecule in P. aeruginosa and the molecular mechanisms involved may help to find new strategies of treatment to fight against this bacterium.

Published
2019
Full Text
View/download PDF

4. Effect of Phthalates and Their Substitutes on the Physiology of Pseudomonas aeruginosa

Author

Mélissande Louis, Ali Tahrioui, Julien Verdon, Audrey David, Sophie Rodrigues, Magalie Barreau, Maëliss Manac’h, Audrey Thiroux, Baptiste Luton, Charly Dupont, Marie Le Calvé, Alexis Bazire, Alexandre Crépin, Maximilien Clabaut, Emilie Portier, Laure Taupin, Florian Defontaine, Thomas Clamens, Emeline Bouffartigues, Pierre Cornelis, Marc Feuilloley, Jocelyne Caillon, Alain Dufour, Jean-Marc Berjeaud, Olivier Lesouhaitier, and Sylvie Chevalier

Subjects
phthalates, Pseudomonas aeruginosa, virulence, biofilm, antibiotic susceptibility, Biology (General), QH301-705.5
Abstract

Phthalates are used in a variety of applications—for example, as plasticizers in polyvinylchloride products to improve their flexibility—and can be easily released into the environment. In addition to being major persistent organic environmental pollutants, some phthalates are responsible for the carcinogenicity, teratogenicity, and endocrine disruption that are notably affecting steroidogenesis in mammals. Numerous studies have thus focused on deciphering their effects on mammals and eukaryotic cells. While multicellular organisms such as humans are known to display various microbiota, including all of the microorganisms that may be commensal, symbiotic, or pathogenic, few studies have aimed at investigating the relationships between phthalates and bacteria, notably regarding their effects on opportunistic pathogens and the severity of the associated pathologies. Herein, the effects of phthalates and their substitutes were investigated on the human pathogen, Pseudomonas aeruginosa, in terms of physiology, virulence, susceptibility to antibiotics, and ability to form biofilms. We show in particular that most of these compounds increased biofilm formation, while some of them enhanced the bacterial membrane fluidity and altered the bacterial morphology.

Published
2022
Full Text
View/download PDF

5. Bioactivity of compounds secreted by symbiont bacteria of Nudibranchs from Indonesia

Author

Rhesi Kristiana, Gilles Bedoux, Gerard Pals, I. Wayan Mudianta, Laure Taupin, Christel Marty, Meezan Ardhanu Asagabaldan, Diah Ayuningrum, Agus Trianto, Nathalie Bourgougnon, Ocky Karna Radjasa, Agus Sabdono, and Muhammad Hanafi

Subjects
Nudibranch, Virgibacillus salarius, Pseudoalteromonas rubra, Antibiotic, HSV-1, Anti-MRSA activity, Medicine, Biology (General), QH301-705.5
Abstract

The aims of this work are to isolate bacterial symbionts from nudibranchs and subsequently to determine anti-Methicillin resistant Staphylococcus aureus (MRSA), cytotoxicity and anti-Herpes simplex virus type 1 (HSV-1) activities of bio compounds. A total of 15 species of nudibranchs were collected from Karimunjawa and five species from Bali, respectively. A total of 245 bacteria isolates were obtained. The anti-MRSA activity screening activity indicated two active bacteria. Ethyl acetate extracts from supernatants, indicating extracelullar compounds, showed an inhibition zone against MRSA at concentrations of 500–1,000 µg/ml. DNA sequence analysis showed that the strain KJB-07 from Phyllidia coelestis was closely related to Pseudoalteromonas rubra, whereas the strain NP31-01 isolated from Phyllidia varicosa was closely related to Virgibacillus salarius. The extract of Pseudoalteromonas rubra was cytotoxic to Vero cells at a concentration of 75 µg/ml. The extract of V. salarius presented no cytotoxicity at concentrations of 5–1,000 µg/ml. No anti HSV-1 was observed for both isolated bacteria. This is the first study describing research on anti-MRSA, cytotoxicity and anti HSV-1 activity of bacterial symbionts from the viscera of nudibranch. Compounds produced by Pseudoalteromonas rubra and V. salarius, had potential anti-MRSA activity. However, only extracts from Pseudoalteromonas rubra showed cytotoxic effects on Vero cells. Three compounds were identified by LC/MS after purification from culture supernatant.

Published
2020
Full Text
View/download PDF

6. Biocontrol of Biofilm Formation: Jamming of Sessile-Associated Rhizobial Communication by Rhodococcal Quorum-Quenching

Author

Yvann Bourigault, Sophie Rodrigues, Alexandre Crépin, Andrea Chane, Laure Taupin, Mathilde Bouteiller, Charly Dupont, Annabelle Merieau, Yoan Konto-Ghiorghi, Amine M. Boukerb, Marie Turner, Céline Hamon, Alain Dufour, Corinne Barbey, and Xavier Latour

Subjects
communication, biofilm, lifestyle switch, Rhizobium (Agrobacterium) rhizogenes, hairy root, quorum-sensing, Biology (General), QH301-705.5, Chemistry, QD1-999
Abstract

Biofilms are complex structures formed by a community of microbes adhering to a surface and/or to each other through the secretion of an adhesive and protective matrix. The establishment of these structures requires a coordination of action between microorganisms through powerful communication systems such as quorum-sensing. Therefore, auxiliary bacteria capable of interfering with these means of communication could be used to prevent biofilm formation and development. The phytopathogen Rhizobium rhizogenes, which causes hairy root disease and forms large biofilms in hydroponic crops, and the biocontrol agent Rhodococcus erythropolis R138 were used for this study. Changes in biofilm biovolume and structure, as well as interactions between rhizobia and rhodococci, were monitored by confocal laser scanning microscopy with appropriate fluorescent biosensors. We obtained direct visual evidence of an exchange of signals between rhizobia and the jamming of this communication by Rhodococcus within the biofilm. Signaling molecules were characterized as long chain (C14) N-acyl-homoserine lactones. The role of the Qsd quorum-quenching pathway in biofilm alteration was confirmed with an R. erythropolis mutant unable to produce the QsdA lactonase, and by expression of the qsdA gene in a heterologous host, Escherichia coli. Finally, Rhizobium biofilm formation was similarly inhibited by a purified extract of QsdA enzyme.

Published
2021
Full Text
View/download PDF

7. Highlighting of quorum sensing lux genes and their expression in the hydrothermal vent shrimp Rimicaris exoculata ectosymbiontic community. Possible use as biogeographic markers.

Author

Simon Le Bloa, Lucile Durand, Valérie Cueff-Gauchard, Josiane Le Bars, Laure Taupin, Charlotte Marteau, Alexis Bazire, and Marie-Anne Cambon-Bonavita

Subjects
Medicine, Science
Abstract

Rimicaris exoculata is a caridean shrimp that dominates the fauna at several hydrothermal vent sites of the Mid-Atlantic Ridge. It has two distinct and stable microbial communities. One of these epibiontic bacterial communities is located in the shrimp gut and has a distribution and role that are poorly understood. The second colonizes its enlarged gill chamber and is involved in host nutrition. It is eliminated after each molt, and has colonization processes reminiscent of those of a biofilm. The presence and expression of genes usually involved in quorum sensing (QS) were then studied. At four sites, Rainbow, TAG, Snake Pit and Logatchev, two lux genes were identified in the R. exoculata epibiontic community at different shrimp molt stages and life stages. RT-PCR experiments highlighted lux gene expression activity at TAG, Snake Pit and Rainbow vent sites. Their potential QS activity and their possible roles in epibiont colonization processes are discussed. Moreover, phylogenetic analysis has shown the presence of three clades for luxS (Epsilonproteobacteria) and four clades for luxR (Gammaproteobacteria) genes, each clade being restricted to a single site. These genes are more divergent than the 16S rRNA one. They could therefore be used as biogeographical genetic markers.

Published
2017
Full Text
View/download PDF

8. Effect of GABA, a Bacterial Metabolite, on Pseudomonas fluorescens Surface Properties and Cytotoxicity

Author

Marc G. J. Feuilloley, Nicole Orange, Laure Taupin, Sylvie Chevalier, Cécile Duclairoir-Poc, Lily Mijouin, Mélanie Hillion, Annelise Chapalain, and Audrey Dagorn

Subjects
host-microbial interactions, cytotoxicity, virulence, bacterial adhesion, lipopolysaccharide, biofilms, pyoverdine, Biology (General), QH301-705.5, Chemistry, QD1-999
Abstract

Different bacterial species and, particularly Pseudomonas fluorescens, can produce gamma-aminobutyric acid (GABA) and express GABA-binding proteins. In this study, we investigated the effect of GABA on the virulence and biofilm formation activity of different strains of P. fluorescens. Exposure of a psychotropic strain of P. fluorescens (MF37) to GABA (10−5 M) increased its necrotic-like activity on eukaryotic (glial) cells, but reduced its apoptotic effect. Conversely, muscimol and bicuculline, the selective agonist and antagonist of eukaryote GABAA receptors, respectively, were ineffective. P. fluorescens MF37 did not produce biosurfactants, and its caseinase, esterase, amylase, hemolytic activity or pyoverdine productions were unchanged. In contrast, the effect of GABA was associated to rearrangements of the lipopolysaccharide (LPS) structure, particularly in the lipid A region. The surface hydrophobicity of MF37 was marginally modified, and GABA reduced its biofilm formation activity on PVC, but not on glass, although the initial adhesion was increased. Five other P. fluorescens strains were studied, and only one, MFP05, a strain isolated from human skin, showed structural differences of biofilm maturation after exposure to GABA. These results reveal that GABA can regulate the LPS structure and cytotoxicity of P. fluorescens, but that this property is specific to some strains.

Published
2013
Full Text
View/download PDF

9. Different Dose-Dependent Modes of Action of C-Type Natriuretic Peptide on Pseudomonas aeruginosa Biofilm Formation

Author

Florie Desriac, Thomas Clamens, Thibaut Rosay, Sophie Rodrigues, Ali Tahrioui, Jérémy Enault, Lucille Roquigny, Pierre-Jean Racine, Laure Taupin, Alexis Bazire, Alain Dufour, Jérôme Leprince, Emeline Bouffartigues, Sylvie Chevalier, Marc G. J. Feuilloley, and Olivier Lesouhaitier

Subjects
biofilm, hormones, peptides, bacterial adaptation, lung, cystic fibrosis, Medicine
Abstract

We have previously shown that the C-type Natriuretic Peptide (CNP), a peptide produced by lungs, is able to impact Pseudomonas aeruginosa physiology. In the present work, the effect of CNP at different concentrations on P. aeruginosa biofilm formation was studied and the mechanisms of action of this human hormone on P. aeruginosa were deciphered. CNP was shown to inhibit dynamic biofilm formation in a dose-dependent manner without affecting the bacterial growth at any tested concentrations. The most effective concentrations were 1 and 0.1 µM. At 0.1 µM, the biofilm formation inhibition was fully dependent on the CNP sensor protein AmiC, whereas it was only partially AmiC-dependent at 1 µM, revealing the existence of a second AmiC-independent mode of action of CNP on P. aeruginosa. At 1 µM, CNP reduced both P. aeruginosa adhesion on glass and di-rhamnolipid production and also increased the bacterial membrane fluidity. The various effects of CNP at 1 µM and 0.1 µM on P. aeruginosa shown here should have major consequences to design drugs for biofilm treatment or prevention.

Published
2018
Full Text
View/download PDF

10. In Planta Biocontrol of Pectobacterium atrosepticum by Rhodococcus erythropolis Involves Silencing of Pathogen Communication by the Rhodococcal Gamma-Lactone Catabolic Pathway.

Author

Corinne Barbey, Alexandre Crépin, Dorian Bergeau, Asma Ouchiha, Lily Mijouin, Laure Taupin, Nicole Orange, Marc Feuilloley, Alain Dufour, Jean-François Burini, and Xavier Latour

Subjects
Medicine, Science
Abstract

The virulence of numerous Gram-negative bacteria is under the control of a quorum sensing process based on synthesis and perception of N-acyl homoserine lactones. Rhodococcus erythropolis, a Gram-positive bacterium, has recently been proposed as a biocontrol agent for plant protection against soft-rot bacteria, including Pectobacterium. Here, we show that the γ-lactone catabolic pathway of R. erythropolis disrupts Pectobacterium communication and prevents plant soft-rot. We report the first characterization and demonstration of N-acyl homoserine lactone quenching in planta. In particular, we describe the transcription of the R. erythropolis lactonase gene, encoding the key enzyme of this pathway, and the subsequent lactone breakdown. The role of this catabolic pathway in biocontrol activity was confirmed by deletion of the lactonase gene from R. erythropolis and also its heterologous expression in Escherichia coli. The γ-lactone catabolic pathway is induced by pathogen communication rather than by pathogen invasion. This is thus a novel and unusual biocontrol pathway, differing from those previously described as protecting plants from phytopathogens. These findings also suggest the existence of an additional pathway contributing to plant protection.

Published
2013
Full Text
View/download PDF

11. Quorum sensing signaling molecules produced by reference and emerging soft-rot bacteria (Dickeya and Pectobacterium spp.).

Author

Alexandre Crépin, Corinne Barbey, Amélie Beury-Cirou, Valérie Hélias, Laure Taupin, Sylvie Reverchon, William Nasser, Denis Faure, Alain Dufour, Nicole Orange, Marc Feuilloley, Karin Heurlier, Jean-François Burini, and Xavier Latour

Subjects
Medicine, Science
Abstract

BackgroundSeveral small diffusible molecules are involved in bacterial quorum sensing and virulence. The production of autoinducers-1 and -2, quinolone, indole and γ-amino butyrate signaling molecules was investigated in a set of soft-rot bacteria belonging to six Dickeya or Pectobacterium species including recent or emerging potato isolates.Methodology/principal findingsUsing bacterial biosensors, immunoassay, and chromatographic analysis, we showed that soft-rot bacteria have the common ability to produce transiently during their exponential phase of growth the N-3-oxo-hexanoyl- or the N-3-oxo-octanoyl-l-homoserine lactones and a molecule of the autoinducer-2 family. Dickeya spp. produced in addition the indole-3-acetic acid in tryptophan-rich conditions. All these signaling molecules have been identified for the first time in the novel Dickeya solani species. In contrast, quinolone and γ-amino butyrate signals were not identified and the corresponding synthases are not present in the available genomes of soft-rot bacteria. To determine if the variations of signal production according to growth phase could result from expression modifications of the corresponding synthase gene, the respective mRNA levels were estimated by reverse transcriptase-PCR. While the N-acyl-homoserine lactone production is systematically correlated to the synthase expression, that of the autoinducer-2 follows the expression of an enzyme upstream in the activated methyl cycle and providing its precursor, rather than the expression of its own synthase.Conclusions/significanceDespite sharing the S-adenosylmethionine precursor, no strong link was detected between the production kinetics or metabolic pathways of autoinducers-1 and -2. In contrast, the signaling pathway of autoinducer-2 seems to be switched off by the indole-3-acetic acid pathway under tryptophan control. It therefore appears that the two genera of soft-rot bacteria have similarities but also differences in the mechanisms of communication via the diffusible molecules. Our results designate autoinducer-1 lactones as the main targets for a global biocontrol of soft-rot bacteria communications, including those of emerging isolates.

Published
2012
Full Text
View/download PDF

12. Epinephrine affects motility, and increases adhesion, biofilm and virulence of Pseudomonas aeruginosa H103

Author

Damien Tortuel, Julie Hardouin, Sophie Rodrigues, Olivier Maillot, Nathalie Connil, Karine Réhel, Kelly Biaggini, Mélyssa Cambronel, Laure Taupin, Marc G. J. Feuilloley, Isabelle Rincé, Cécile Muller, Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Unité de Recherche Risques Microbiens (U2RM), and Université de Caen Normandie (UNICAEN)

Subjects
0301 basic medicine, Epinephrine, Science, 030106 microbiology, Motility, Virulence, medicine.disease_cause, Article, Bacterial Adhesion, Cell Line, Microbiology, 03 medical and health sciences, Immune system, In vivo, medicine, Humans, Multidisciplinary, biology, Chemistry, Pseudomonas aeruginosa, Biofilm, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Galleria mellonella, 030104 developmental biology, [SDU]Sciences of the Universe [physics], Biofilms, Medicine, Pathogens, Bacteria
Abstract

Microbial endocrinology has demonstrated for more than two decades, that eukaryotic substances (hormones, neurotransmitters, molecules of the immune system) can modulate the physiological behavior of bacteria. Among them, the hormones/neurotransmitters, epinephrine (Epi) and norepinephrine (NE), released in case of stress, physical effort or used in medical treatment, were shown to be able to modify biofilm formation in various bacterial species. In the present study, we have evaluated the effect of Epi on motility, adhesion, biofilm formation and virulence of Pseudomonas aeruginosa, a bacterium linked to many hospital-acquired infections, and responsible for chronic infection in immunocompromised patients including persons suffering from cystic fibrosis. The results showed that Epi increased adhesion and biofilm formation of P. aeruginosa, as well as its virulence towards the Galleria mellonella larvae in vivo model. Deciphering the sensor of this molecule in P. aeruginosa and the molecular mechanisms involved may help to find new strategies of treatment to fight against this bacterium.

Published
2019

13. Stress tolerance and photoadaptation to solar radiation in Rhodymenia pseudopalmata (Rhodophyta) through mycosporine-like amino acids, phenolic compounds, and pigments in an Integrated Multi-Trophic Aquaculture system

Author

Hugo Pliego-Cortés, Nathalie Bourgougnon, Gilles Bedoux, Daniel Robledo, Romain Boulho, Laure Taupin, Yolanda Freile-Pelegrín, Laboratoire de Biotechnologie et Chimie Marine (LBCM), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Bretagne Sud (UBS), Institut Universitaire Européen de la Mer (IUEM), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, Photoinhibition, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, DPPH, 01 natural sciences, 03 medical and health sciences, Pigment, chemistry.chemical_compound, otorhinolaryngologic diseases, [CHIM]Chemical Sciences, 14. Life underwater, Food science, Integrated multi-trophic aquaculture, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, 010604 marine biology & hydrobiology, Thallus, Salinity, chemistry, 13. Climate action, Photosynthetically active radiation, Photoprotection, visual_art, visual_art.visual_art_medium, Agronomy and Crop Science
Abstract

Rhodymenia pseudopalmata lives in the intertidal zone receiving high doses of solar radiation, including the potentially harmful UVR. Previous studies proved it ability to adapt to different artificial light intensities and salinity concentrations. The aim of this study was to describe the differences on the Mycosporine-like amino acids (MAAs), phenolic compounds, and pigments of R. pseudopalmata due to exposure to high solar radiation. Vegetative thalli were exposed to solar radiation using a Solar Exposure Chambers System (SECS) under an Integrated Multi-Trophic Aquaculture (IMTA) approach with marine fish culture. Samples from natural populations in Playa de Carmen, Mexico were included as reference. The biosynthesis of MAAs, and phenolic compounds were stimulated as a response to the stress caused by the exposure to high solar irradiation. Liquid Chromatography-Mass Spectrometry (LC-MS) revealed seven MAAs and their precursor deoxygadusol. Five MAAs were partially characterized through MS2 and fragmentation patterns suggested a common fragmentation pattern pathway. After seven days (D7), the MAAs total content was significant five-fold higher compared to wild populations (0.26 ± 0.1 mg g−1 DW). The Individual composition increased from four MAAs at D0, up to eight at D7, including deoxygadusol, palythene and usujirene, MAAs with high antioxidant activity. At D7, phenolic compounds increased up to 20%, and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity reduced the IC50 to 4.0 ± 0.6 mg mL−1. The pigment content, Phycoerythrin (PE):Chl-a, and MAAs:Chl-a ratios might confer a unique photoprotection role from PE and MAAs to Chl-a. Similarly, Fv/Fm which was adapted to the variations of Photosynthetic Active Radiation (PAR) indicated a process of dynamic photoinhibition. Overall, our results evidenced the ability of this species to tolerate the stress to high solar irradiance and suggested the photoadaptation of the thalli. Farming possibilities, expected MAAs productivity, potential applications of MAAs and ecological considerations are also discussed.

Published
2019

14. New insights into Pseudomonas aeruginosa adaptive response to sublethal concentrations of tobramycin

Author

Ali Tahrioui, Rachel Duchesne, Emeline Bouffartigues, Sophie Rodrigues, Olivier Maillot, Damien Tortuel, Julie Hardouin, Laure Taupin, Marie-Christine Groleau, Alain Dufour, Éric Déziel, Marc Feuilloley, Nicole Orange, Olivier Lesouhaitier, Pierre Cornelis, sylvie CHEVALIER, Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Polymères Biopolymères Surfaces (PBS), Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Institut Normand de Chimie Moléculaire Médicinale et Macromoléculaire (INC3M), Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Armand Frappier (INRS-IAF), and Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP)

Subjects
[SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BBM.MN]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular Networks [q-bio.MN], biochemical phenomena, metabolism, and nutrition, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

International audience; Background: Biofilms are structured microbial communities that are the leading cause of numerous chronic infections which are difficult to eradicate. Within the lungs of individuals with cystic fibrosis, Pseudomonas aeruginosa causes persistent biofilm infection that is commonly treated with aminoglycoside antibiotics such as tobramycin. However, exposure to sublethal concentrations of the aminoglycoside tobramycin were previously shown to increase biofilm formation by P. aeruginosa Objectives: In the current study, we sought to elucidate potential adaptive mechanisms shaping the tobramycin-enhanced biofilm formation in P. aeruginosa. Methods: We combined confocal laser scanning microscope analyses, proteomics profiling, gene expression assays and phenotypic studies to unravel P. aeruginosa potential adaptive mechanisms in response to tobramycin exposure during biofilm growth. Results: We show that the modified biofilm architecture is related at least in part to increased extracellular DNA (eDNA) release, most likely as a result of biofilm cell death. Furthermore, the activity of quorum sensing (QS) systems was increased, leading to higher production of QS molecules. We also demonstrate upon tobramycin exposure an increase in expression of the small RNAs PrrF1 and PrrF2, known for promoting 4-hydroxy-2-alkylquinolines production, as well as expression of iron uptake systems. Remarkably, biofilm biovolumes and eDNA relative abundances in pqs and prrF1,F2 mutant strains decrease in the presence of tobramycin. Overall, our findings offer experimental evidences for a potential adaptive mechanism linking PrrF1/F2 sRNAs, QS signaling, biofilm cell death, eDNA release, and tobramycin-enhanced biofilm formation in P. aeruginosa.

Published
2019

15. Extracellular DNA release, quorum sensing, and PrrF1/F2 small RNAs are key players in Pseudomonas aeruginosa tobramycin-enhanced biofilm formation

Author

Sophie Rodrigues, Olivier Maillot, Nicole Orange, Gérard Brenner-Weiss, Eric Déziel, Emeline Bouffartigues, Alain Dufour, Pierre Cornelis, Rachel Duchesne, Marie-Christine Groleau, Laure Taupin, Marc G. J. Feuilloley, Julie Hardouin, Damien Tortuel, Sylvie Chevalier, Ali Tahrioui, Olivier Lesouhaitier, Vriendenkring VUB, Microbiology, Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Polymères Biopolymères Surfaces (PBS), Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Institut Normand de Chimie Moléculaire Médicinale et Macromoléculaire (INC3M), Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), Karlsruhe Institute of Technology (KIT), The LMSM is supported by the Région Normandie (France), Evreux Portes de Normandie (France), European FEDER funds and the French Association 'Vaincre la Mucoviscidose'. A.T. is supported by a post-doctoral fellowship from European Union (FEDER) and Région Normandie (France). D.T. and R.D. were supported by doctoral fellowships from the Région Normandie (France)., Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Institut Normand de Chimie Moléculaire Médicinale et Macromoléculaire (INC3M), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
DNA, Bacterial, Proteomics, Life sciences, biology, Cell signaling, [SDV]Life Sciences [q-bio], Mutant, medicine.disease_cause, Applied Microbiology and Biotechnology, Microbiology, Article, lcsh:Microbial ecology, 03 medical and health sciences, Bacterial Proteins, Stress, Physiological, ddc:570, Gene expression, Tobramycin, medicine, 030304 developmental biology, 0303 health sciences, Microscopy, Confocal, Antimicrobials, 030306 microbiology, Pseudomonas aeruginosa, Chemistry, Gene Expression Profiling, Aminoglycoside, Biofilm, Quorum Sensing, biochemical phenomena, metabolism, and nutrition, Anti-Bacterial Agents, Quorum sensing, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Biofilms, RNA, Small Untranslated, lcsh:QR100-130, Pathogens, Biotechnology, medicine.drug
Abstract

Biofilms are structured microbial communities that are the leading cause of numerous chronic infections which are difficult to eradicate. Within the lungs of individuals with cystic fibrosis (CF), Pseudomonas aeruginosa causes persistent biofilm infection that is commonly treated with aminoglycoside antibiotics such as tobramycin. However, sublethal concentrations of this aminoglycoside were previously shown to increase biofilm formation by P. aeruginosa, but the underlying adaptive mechanisms still remain elusive. Herein, we combined confocal laser scanning microscope analyses, proteomics profiling, gene expression assays and phenotypic studies to unravel P. aeruginosa potential adaptive mechanisms in response to tobramycin exposure during biofilm growth. Under this condition, we show that the modified biofilm architecture is related at least in part to increased extracellular DNA (eDNA) release, most likely as a result of biofilm cell death. Furthermore, the activity of quorum sensing (QS) systems was increased, leading to higher production of QS signaling molecules. We also demonstrate upon tobramycin exposure an increase in expression of the PrrF small regulatory RNAs, as well as expression of iron uptake systems. Remarkably, biofilm biovolumes and eDNA relative abundances in pqs and prrF mutant strains decrease in the presence of tobramycin. Overall, our findings offer experimental evidences for a potential adaptive mechanism linking PrrF sRNAs, QS signaling, biofilm cell death, eDNA release, and tobramycin-enhanced biofilm formation in P. aeruginosa. These specific adaptive mechanisms should be considered to improve treatment strategies against P. aeruginosa biofilm establishment in CF patients’ lungs.

Published
2019

16. Photo-protective compounds in red macroalgae from Brittany: Considerable diversity in mycosporine-like amino acids (MAAs)

Author

Fanny Lalegerie, Laure Taupin, Valérie Stiger-Pouvreau, Sirine Lajili, Solène Connan, Gilles Bedoux, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Bretagne Sud (UBS), Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, Pigments, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, Algae, Ultraviolet Rays, Red algae, Aquatic Science, Oceanography, 010603 evolutionary biology, 01 natural sciences, Pigment, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Botany, otorhinolaryngologic diseases, Metabolites, Photo-protection, 14. Life underwater, MAAs, Amino Acids, Carotenoid, Phylogeny, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, Abiotic component, chemistry.chemical_classification, Diversity, biology, Chemistry, 010604 marine biology & hydrobiology, Phycobiliprotein, ACL, General Medicine, Seaweed, biology.organism_classification, Adaptation, Physiological, Pollution, Amino acid, visual_art, Rhodophyta, visual_art.visual_art_medium, Screening, Composition (visual arts), France, HPLC
Abstract

International audience; To cope with the biotic and abiotic stresses experienced within their environment, marine macroalgae have developed certain defence mechanisms including the synthesis of photo-protective molecules against light and particularly harmful UV radiation. The aim of this study was to screen selected red algae, a highly diverse phylogenetic group, for the production of photo-protective molecules. The pigment content and composition (Le. chlorophyll-a, phycobiliproteins and carotenoids) and the composition of mycosporine-like amino acids (MAAs) were studied in 40 species of red macroalgae collected in Brittany (France), at two distinct periods (i.e. February and July 2017). A high inter-specific variability was demonstrated in terms of pigment content and MAA composition. Twenty-three potential MAAs were detected by HPLC, and six were identified by LC-MS (i.e. shinorine, palythine, asterina-330, porphyra-334, usurijene and palythene). This is the first study to report on the composition of pigments and MAAs in a diverse group of red seaweeds from Brittany, including some species for which the MAA composition has never been studied before. Nevertheless, the results suggested that some species of red algae are more likely to cope with high levels of light radiation since those species such as Bostrychia scorpioides, Porphyra dioica, Gracilaria vermiculophylla and Vertebrata lanosa are living in environments exposed to higher levels of irradiation, and had various MAAs in addition to their photo-protective pigments.

Published
2019

17. Régulation et Rôle de CmpX chez Pseudomonas aeruginosa

Author

Emeline Bouffartigues, Damien Tortuel, Olivier Maillot, Audrey David, Jordane Omnes, Ali Tahiroui, Cecil Azuama, Laure Taupin, Ségolène Depayras, Cécile Duclairoir Poc, Heipieper, Hermann J., Alain Dufour, Olivier Lesouhaitier, Nicole Orange, Marc Feuilloley, Pierre Cornelis, sylvie CHEVALIER, Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Environmental Biotechnology [UFZ Leipzig], Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ), and DUCLAIROIR POC, Cécile

Subjects
[SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, [SDV.BC.IC] Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

International audience; Les canaux ioniques mécanosensibles sont des protéines ubiquitaires dont l’ouverture sous l’effet de contraintes membranaires permet le passage d’ions ou de molécules selon la sélectivité de celui-ci. Chez Escherichia coli, le canal de faible conductance MscS est l’un des plus étudiés. Il est impliqué dans la régulation de la pression de turgescence lors d’un abaissement brusque de l’osmolarité du milieu et son gène est régulé par RpoS, le facteur sigma de phase stationnaire. Chez Pseudomonas aeruginosa, CmpX, qui possède 52% de similarité de séquence avec MscS, est une protéine de fonction inconnue. Nous avons montré que son gène fait partie avec cfrX d’une unité transcriptionnelle localisée en amont de sigX et d’oprF. SigX est un facteur sigma à fonction extracytoplasmique (ECF) de réponse au stress d’enveloppe, qui contrôle de manière directe l’expression de cfrX-cmpX, et dont l’activité est régulée négativement par CfrX à partir de la fin de phase exponentielle. OprF, la protéine majoritaire de la membrane externe est impliquée dans l’intégrité de l’enveloppe et la perception de l’environnement. Dans le but de préciser rôle de CmpX, un mutant de délétion a été construit chez la souche H103 et caractérisé aux niveaux moléculaire (qRT-PCR) et phénotypique pour (i) sa résistance à des chocs thermiques, (ii) sa fluidité (polarisation généralisée et de fluorescence) et sa composition membranaire (FAME), (iii) sa production de facteurs de virulence. Nous montrons que l’absence de CmpX provoque en phase stationnaire une diminution de la fluidité des régions profondes du core hydrophobe des membranes, l’activation de la réponse au stress d’enveloppe et une augmentation de l’expression de relA et spoT dont les produits sont impliqués dans le métabolisme du ppGpp. Ces altérations membranaires sont associées à une diminution de la production de rhamnolipides, un facteur de virulence sous le contrôle du système de communication Rhl. Ces travaux suggèrent que CmpX joue un rôle primordial dans l’homéostasie de l’enveloppe et la pathogénicité chez P. aeruginosa dans des conditions de stress telles que la phase stationnaire

Published
2018

18. Different Dose-Dependent Modes of Action of C-Type Natriuretic Peptide on Pseudomonas aeruginosa Biofilm Formation

Author

Thomas Clamens, Jérôme Leprince, Ali Tahrioui, Sophie Rodrigues, Olivier Lesouhaitier, Jérémy Enault, Lucille Roquigny, Alexis Bazire, Alain Dufour, Sylvie Chevalier, Thibaut Rosay, Florie Desriac, Laure Taupin, Marc G. J. Feuilloley, Emeline Bouffartigues, Pierre-Jean Racine, Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Différenciation et communication neuronale et neuroendocrine (DC2N), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), and Neuroendocrinologie cellulaire et moléculaire

Subjects
0301 basic medicine, Microbiology (medical), medicine.drug_class, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, 030106 microbiology, bacterial adaptation, lcsh:Medicine, Peptide, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, Bacterial growth, medicine.disease_cause, biofilm, lung, cystic fibrosis, 03 medical and health sciences, [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Membrane fluidity, medicine, Natriuretic peptide, Immunology and Allergy, Mode of action, Molecular Biology, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, General Immunology and Microbiology, hormones, Pseudomonas aeruginosa, lcsh:R, Biofilm, Adhesion, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, peptides, Infectious Diseases, chemistry, Biophysics, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology
Abstract

International audience; We have previously shown that the C-type Natriuretic Peptide (CNP), a peptide produced by lungs, is able to impact Pseudomonasaeruginosa physiology. In the present work, the effect of CNP at different concentrations on P. aeruginosa biofilm formation was studied and the mechanisms of action of this human hormone on P. aeruginosa were deciphered. CNP was shown to inhibit dynamic biofilm formation in a dose-dependent manner without affecting the bacterial growth at any tested concentrations. The most effective concentrations were 1 and 0.1 µM. At 0.1 µM, the biofilm formation inhibition was fully dependent on the CNP sensor protein AmiC, whereas it was only partially AmiC-dependent at 1 µM, revealing the existence of a second AmiC-independent mode of action of CNP on P. aeruginosa. At 1 µM, CNP reduced both P. aeruginosa adhesion on glass and di-rhamnolipid production and also increased the bacterial membrane fluidity. The various effects of CNP at 1 µM and 0.1 µM on P. aeruginosa shown here should have major consequences to design drugs for biofilm treatment or prevention.

Published
2018

19. Tobramycine et biofilm : une histoire revisitée

Author

Ali Tahrioui, Rachel Duchesne, Julie Hardouin, Olivier Maillot, Laure Taupin, Alain Dufour, Éric Déziel, Nicole Orange, Marc Feuilloley, Emeline Bouffartigues, sylvie CHEVALIER, Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Polymères Biopolymères Surfaces (PBS), Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Institut Normand de Chimie Moléculaire Médicinale et Macromoléculaire (INC3M), Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), Tahrioui, Ali, and Université de Brest (UBO)-Université de Bretagne Sud (UBS)-Institut Universitaire Européen de la Mer (IUEM)

Subjects
[SDV.BBM.MN] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular Networks [q-bio.MN], [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BBM.MN]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular Networks [q-bio.MN], [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

International audience; Pseudomonas aeruginosa est un pathogène opportuniste de l'Homme, qui en mode de vie biofilm, entraîne des infections de type chronique principalement au niveau des systèmes respiratoire et urinaire. La tobramycine, un antibiotique de la famille des aminoglycosides, provoque en concentration subinhibitrice, une augmentation de la formation du biofilm. L'observation en microscopie confocale à balayage laser de l'effet d'une telle concentration sur P. aeruginosa montre une modification de l'architecture du biofilm, avec notamment une augmentation de la quantité d'ADN extracellulaire dans la matrice. Dans ce contexte l'objectif principal de ce travail est de comprendre les mécanismes moléculaires impliqués dans l'augmentation de biofilm chez P. aeruginosa en réponse à une concentration subinhibitrice de tobramycine. L'analyse globale du protéome par spectrométrie de masse en tandem (LTQ-Orbitrap) de P. aeruginosa cultivée en biofilm montre une dérégulation de la production de 174 protéines appartenant principalement aux classes fonctionnelles (PseudoCAP), « Facteurs sécrétés », « Facteurs impliqués dans la transcription, et le métabolisme des ARNs », et « Métabolismes (énergétique, carboné, acides aminés, nucléotides ». L'expression de différentes cibles, choisies dans chaque classe fonctionnelle, a été évaluée en RT-PCR quantitative, et différents essais phénotypiques pour conforter ces données ont été réalisés. De manière remarquable, en plus d'induire la biosynthèse des pompes à efflux impliquées dans la réponse aux aminoglycosides, les résultats montrent que la tobramycine induit chez P. aeruginosa cultivée en biofilm une augmentation de la production des molécules du quorum sensing (N-acyl-homosérine lactones et 2-alkyl-4-quinolones) et de l'expression de plusieurs petits ARNs non codants. L'ensemble de ces données suggère différents modes d'action moléculaires de la tobramycine qui pourrait contribuer à l'augmentation de la formation de biofilm chez P. aeruginosa.

Published
2017

20. Chemical characterization and photoprotective activity measurement of extracts from the red macroalga Solieria chordalis

Author

Laurent Vandanjon, Christel Marty, Gilles Bedoux, Kevin Hardouin, Nathalie Bourgougnon, Laure Taupin, Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Mines Nantes (Mines Nantes)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_classification, Chromatography, medicine.diagnostic_test, palythenic acid, Carboxylic acid, [SDV]Life Sciences [q-bio], Extraction (chemistry), Solieria chordalis, mycosporine-like amino acid, Plant Science, Aquatic Science, Amino acid, chemistry.chemical_compound, Mycosporine-like amino acid, chemistry, Biochemistry, Spectrophotometry, Chlorophyll, medicine, Dodecanol, Carotenoid, photoprotective activity, Ecology, Evolution, Behavior and Systematics
Abstract

The photoadaptive responses of macroalgal communities to abiotic stresses have been studied, and a number of UV-absorbing molecules have been identified. Among these compounds, photoprotective compounds such as mycosporine-like amino acids and carotenoids have been isolated from various red macroalgal species. However, several substances still need to be characterized. We describe the preparation of photoprotective extracts obtained from Solieria chordalis. Two solvents, 2-octyl dodecanol and octyldodecyl ester of l-pyrrolidone carboxylic acid, were selected based on their cosmetic functions for performing an ultrasound-assisted extraction. The efficiency of extraction was monitored by spectrophotometry and in vitro photoprotective activity measurements. 2-Octyl dodecanol and octyldodecyl ester of l-pyrrolidone carboxylic acid extracts showed maximum absorption wavelengths ranging from 280 to 340 nm and 270 to 350 nm, respectively. The anti UV-B capacity for protecting a synthetic chlorophyll solution was assessed by measuring its pseudo first-order degradation kinetics at room temperature. Under irradiation at 312 nm, chlorophyll introduced in the 2-octyl dodecanol S. chordalis extract showed the slowest degradation kinetics with a half-life t1/2 of 121.0 min. Several compounds were detected in the seaweed extract by high-performance liquid chromatography. Among them, the mycosporine-like amino acid, palythenic acid, was detected in the algal extract.

Published
2014

21. Effect of GABA, a Bacterial Metabolite, on Pseudomonas fluorescens Surface Properties and Cytotoxicity

Author

Cécile Duclairoir-Poc, Audrey Dagorn, Sylvie Chevalier, Laure Taupin, Marc G. J. Feuilloley, Nicole Orange, Annelise Chapalain, Lily Mijouin, Mélanie Hillion, Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Pathogenèse des légionelles- Legionella pathogenesis (LegioPath), Centre International de Recherche en Infectiologie - UMR (CIRI), Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), CHEVALIER, Sylvie, Centre International de Recherche en Infectiologie (CIRI), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Lipopolysaccharides, MESH: Cell Death, MESH: gamma-Aminobutyric Acid, lcsh:Chemistry, Diffusion, Lipid A, chemistry.chemical_compound, MESH: Animals, lcsh:QH301-705.5, MESH: GABA-A Receptor Antagonists, MESH: Receptors, GABA-A, gamma-Aminobutyric Acid, Spectroscopy, 0303 health sciences, Pyoverdine, Cell Death, biology, host-microbial interactions, cytotoxicity, virulence, bacterial adhesion, lipopolysaccharide, biofilms, pyoverdine, Muscimol, GABAA receptor, MESH: Diffusion, General Medicine, Computer Science Applications, Biochemistry, MESH: Oligopeptides, MESH: Neuroglia, Neuroglia, Oligopeptides, medicine.drug, MESH: Rats, Surface Properties, Pseudomonas fluorescens, MESH: Biofilms, Bicuculline, Article, Catalysis, Microbiology, Inorganic Chemistry, MESH: Pseudomonas fluorescens, 03 medical and health sciences, Caseinase, MESH: Bicuculline, medicine, Animals, Humans, GABA-A Receptor Agonists, GABA-A Receptor Antagonists, MESH: Bacterial Adhesion, MESH: GABA-A Receptor Agonists, Physical and Theoretical Chemistry, Molecular Biology, 030304 developmental biology, MESH: Surface Properties, MESH: Humans, 030306 microbiology, Organic Chemistry, Biofilm, Receptors, GABA-A, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Rats, lcsh:Biology (General), lcsh:QD1-999, chemistry, nervous system, MESH: Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, biology.protein, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, MESH: Lipopolysaccharides, MESH: Muscimol
Abstract

International audience; Different bacterial species and, particularly Pseudomonas fluorescens, can produce gamma-aminobutyric acid (GABA) and express GABA-binding proteins. In this study, we investigated the effect of GABA on the virulence and biofilm formation activity of different strains of P. fluorescens. Exposure of a psychotropic strain of P. fluorescens (MF37) to GABA (10-5 M) increased its necrotic-like activity on eukaryotic (glial) cells, but reduced its apoptotic effect. Conversely, muscimol and bicuculline, the selective agonist and antagonist of eukaryote GABAA receptors, respectively, were ineffective. P. fluorescens MF37 did not produce biosurfactants, and its caseinase, esterase, amylase, hemolytic activity or pyoverdine productions were unchanged. In contrast, the effect of GABA was associated to rearrangements of the lipopolysaccharide (LPS) structure, particularly in the lipid A region. The surface hydrophobicity of MF37 was marginally modified, and GABA reduced its biofilm formation activity on PVC, but not on glass, although the initial adhesion was increased. Five other P. fluorescens strains were studied, and only one, MFP05, a strain isolated from human skin, showed structural differences of biofilm maturation after exposure to GABA. These results reveal that GABA can regulate the LPS structure and cytotoxicity of P. fluorescens, but that this property is specific to some strains.

Published
2013

22. Gamma-aminobutyric acid acts as a specific virulence regulator in Pseudomonas aeruginosa

Author

Sylvie Chevalier, Laure Taupin, Marc G. J. Feuilloley, Annelise Chapalain, Mélanie Hillion, Julien Vieillard, Olivier Lesouhaitier, Cécile Duclairoir Poc, Audrey Dagorn, Franck Le Derf, Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), Chimie Organique et Bioorganique : Réactivité et Analyse (COBRA), Institut Normand de Chimie Moléculaire Médicinale et Macromoléculaire (INC3M), Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie Organique Fine (IRCOF), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Proteome, Virulence Factors, Bacterial Toxins, Virulence, Biology, medicine.disease_cause, Microbiology, gamma-Aminobutyric acid, 03 medical and health sciences, medicine, Pseudomonas exotoxin, Animals, Secretion, Caenorhabditis elegans, gamma-Aminobutyric Acid, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, 030306 microbiology, Pseudomonas aeruginosa, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Biofilm, Gene Expression Regulation, Bacterial, Survival Analysis, Elongation factor, Quorum sensing, nervous system, Biochemistry, Locomotion, medicine.drug
Abstract

Gamma-aminobutyric acid (GABA) is widespread in the environment and can be used by animal and plants as a communication molecule. Pseudomonas species, in particular fluorescent ones, synthesize GABA and express GABA-binding proteins. In this study, we investigated the effects of GABA on the virulence of Pseudomonas aeruginosa. While exposure to GABA (10 µM) did not modify either the growth kinetics or the motility of the bacterium, its cytotoxicity and virulence were strongly increased. The Caenorhabditis elegans ‘fast killing test’ model revealed that GABA acts essentially through an increase in diffusible toxin(s). GABA also modulates the biofilm formation activity and adhesion properties of PAO1. GABA has no effect on cell surface polarity, biosurfactant secretion or on the lipopolysaccharide structure. The production of several exo-enzymes, pyoverdin and exotoxin A is not modified by GABA but we observed an increase in cyanogenesis which, by itself, could explain the effect of GABA on P. aeruginosa virulence. This mechanism appears to be regulated by quorum sensing. A proteomic analysis revealed that the effect of GABA on cyanogenesis is correlated with a reduction of oxygen accessibility and an over-expression of oxygen-scavenging proteins. GABA also promotes specific changes in the expression of thermostable and unstable elongation factors Tuf/Ts involved in the interaction of the bacterium with the host proteins. Taken together, these results suggest that GABA is a physiological regulator of P. aeruginosa virulence.

Published
2013

23. Quorum Sensing Signaling Molecules Produced by Reference and Emerging Soft-Rot Bacteria (Dickeya and Pectobacterium spp.)

Author

Nicole Orange, Alexandre Crépin, Sylvie Reverchon, Valérie Hélias, Jean-François Burini, Corinne Barbey, Denis Faure, Karin Heurlier, Xavier Latour, William Nasser, Amélie Beury-Cirou, Alain Dufour, Laure Taupin, Marc G. J. Feuilloley, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Chromatine et Régulation de la Pathogénie bactérienne (CRP), Microbiologie, adaptation et pathogénie (MAP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), European Union, Conventions Industrielles de Formation par la Recherche (CIFRE), Conseil Regional de Haute-Normandie & Ministere delegue a l'Enseignement Superieur et a la Recherche through the Grand Reseau de recherche Regional Vegetal, Agronomie, Sols et Innovations, National Association of Technical Research through the Compte d'Affectation Speciale pour le Developpement Agricole et Rural, [CAS-DAR AAP 7124], Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
MESH: Signal Transduction, TO-CELL COMMUNICATION, Pectobacterium, MESH: gamma-Aminobutyric Acid, Acyl-Butyrolactones, Quinolones, MESH: Multienzyme Complexes, ACYL-HOMOSERINE LACTONE, CAROTOVORA SUBSP ATROSEPTICA, III SECRETION SYSTEM, PLANT PATHOGEN PECTOBACTERIUM, N-ACYLHOMOSERINE LACTONES, ERWINIA-CAROTOVORA, PSEUDOMONAS-AERUGINOSA, AGROBACTERIUM-TUMEFACIENS, SALMONELLA-TYPHIMURIUM, MESH: Quorum Sensing, Lactones, Plant Microbiology, 4-Butyrolactone, MESH: Bacterial Proteins, MESH: Homoserine, gamma-Aminobutyric Acid, MESH: Acyl-Butyrolactones, 0303 health sciences, Multidisciplinary, biology, MESH: Kinetics, MESH: Pectobacterium, Tryptophan, Quorum Sensing, Agriculture, Bacterial Pathogens, Host-Pathogen Interaction, Biochemistry, Medicine, MESH: Lactones, Signal Transduction, Research Article, Cell signaling, MESH: Indoleacetic Acids, Science, Virulence, Dickeya, Crops, MESH: Solanum tuberosum, Microbiology, 03 medical and health sciences, MESH: Enterobacteriaceae, Integrated Control, Bacterial Proteins, Enterobacteriaceae, Multienzyme Complexes, Microbial Control, Homoserine, RNA, Messenger, Biology, MESH: Tryptophan, 030304 developmental biology, MESH: RNA, Messenger, Solanum tuberosum, MESH: Quinolones, Indoleacetic Acids, 030306 microbiology, Crop Diseases, Computational Biology, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Crop Management, Signaling Networks, Quorum sensing, Metabolic pathway, Kinetics, MESH: 4-Butyrolactone, Pest Control, Dickeya solani, Bacteria
Abstract

International audience; BACKGROUND: Several small diffusible molecules are involved in bacterial quorum sensing and virulence. The production of autoinducers-1 and -2, quinolone, indole and γ-amino butyrate signaling molecules was investigated in a set of soft-rot bacteria belonging to six Dickeya or Pectobacterium species including recent or emerging potato isolates. METHODOLOGY/PRINCIPAL FINDINGS: Using bacterial biosensors, immunoassay, and chromatographic analysis, we showed that soft-rot bacteria have the common ability to produce transiently during their exponential phase of growth the N-3-oxo-hexanoyl- or the N-3-oxo-octanoyl-l-homoserine lactones and a molecule of the autoinducer-2 family. Dickeya spp. produced in addition the indole-3-acetic acid in tryptophan-rich conditions. All these signaling molecules have been identified for the first time in the novel Dickeya solani species. In contrast, quinolone and γ-amino butyrate signals were not identified and the corresponding synthases are not present in the available genomes of soft-rot bacteria. To determine if the variations of signal production according to growth phase could result from expression modifications of the corresponding synthase gene, the respective mRNA levels were estimated by reverse transcriptase-PCR. While the N-acyl-homoserine lactone production is systematically correlated to the synthase expression, that of the autoinducer-2 follows the expression of an enzyme upstream in the activated methyl cycle and providing its precursor, rather than the expression of its own synthase. CONCLUSIONS/SIGNIFICANCE: Despite sharing the S-adenosylmethionine precursor, no strong link was detected between the production kinetics or metabolic pathways of autoinducers-1 and -2. In contrast, the signaling pathway of autoinducer-2 seems to be switched off by the indole-3-acetic acid pathway under tryptophan control. It therefore appears that the two genera of soft-rot bacteria have similarities but also differences in the mechanisms of communication via the diffusible molecules. Our results designate autoinducer-1 lactones as the main targets for a global biocontrol of soft-rot bacteria communications, including those of emerging isolates.

Published
2012

24. N-acyl homoserine lactone production by bacteria within the sponge Suberites domuncula (Olivi, 1792) (Porifera, Demospongiae)

Author

Gaël Le Pennec, Jasnizat Bin Saïdin, Laure Taupin, Alain Dufour, Johan Gardères, Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Bazire, Alexis

Subjects
Aquatic Science, Microbiology, 03 medical and health sciences, chemistry.chemical_compound, Bioluminescence, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Ecology, biology, 030306 microbiology, food and beverages, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, In vitro, Suberites domuncula, Sponge, N-Acyl homoserine lactone, chemistry, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Lactone, Bacteria, Suberites
Abstract

Many bacteria live in close association with sponges. Within these consortia, molecules of communication such as quorum-sensing and hormone-like molecules may occur in order to regulate the partnership. Of particular interest, bacterial N-acyl-l-homoserine lactones (AHLs) were screened in supernatants from Suberites domuncula-associated bacteria using an E. coli bioluminescent reporter system. These sponge-associated bacteria were beforehand isolated on several media supplemented or not with a sponge extract to attempt to isolate sponge-specific bacteria. Out of 81 AHL-producing bacteria, three strains requiring sponge extract to grow were selected for AHL characterization. The in vitro produced AHLs, that is, in bacterial culture supernatants, were identified as N-(3-butanoyl)-l-homoserine lactone and N-(3-oxododecanoyl)-l-homoserine lactone and quantified using LC–ESI–MS/MS. The in vivo production of AHLs by sponge-associated bacteria has also been demonstrated in a healthy host for the first time: N-(3-oxododecanoyl)-l-homoserine lactone, N-(3-hexanoyl)-l-homoserine lactone, and N-(3-heptanoyl)-l-homoserine lactone. This AHL production in sponges may suggest a potential role of these molecules between sponge-associated bacteria and/or between sponge-associated bacteria and the sponge.

Published
2012

25. Full virulence of Pseudomonas aeruginosa requires OprF

Author

Nathalie Connil, Alain Dufour, Laurène Fito-Boncompte, Bertrand Toussaint, Sylvie Chevalier, Hichem Chaker, Alexis Bazire, Qing Wei, Wilfried Veron, Eric Déziel, Pierre Cornelis, Laure Taupin, Marc G. J. Feuilloley, Emeline Bouffartigues, Koki Shioya, Amar Madi, Gwendoline Gicquel, Nicole Orange, Annelise Chapalain, Olivier Lesouhaitier, Department of Bio-engineering Sciences, Microbial Interactions, Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), TheREx, Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications, Grenoble - UMR 5525 (TIMC-IMAG), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratory of Microbial Interactions, Vrije Universiteit Brussel (VUB)-Flanders institute of biotechnology-DEPARTMENT OF MOLECULAR AND CELLULAR INTERACTIONS, and This work was supported by the Communauté d'Agglomération d'Evreux, France (doctoral fellowship to L.F.-B.), European FEDER funds to the LBCM and to the LMDF-SME, and the Ministère de la Recherche et de la Technologie, France (postdoctoral fellowship to K.S.).

Subjects
[SDV.BIO]Life Sciences [q-bio]/Biotechnology, MESH: Virulence, Quinolones, medicine.disease_cause, MESH: Quorum Sensing, Virulence factor, Type three secretion system, Chicory, chemistry.chemical_compound, MESH: Reverse Transcriptase Polymerase Chain Reaction, MESH: Animals, [INFO.INFO-BT]Computer Science [cs]/Biotechnology, MESH: Bacterial Secretion Systems, MESH: Bacterial Proteins, Bacterial Secretion Systems, 0303 health sciences, MESH: Gene Expression Regulation, Bacterial, Virulence, Reverse Transcriptase Polymerase Chain Reaction, MESH: Pseudomonas Infections, Quorum Sensing, MESH: Plant Leaves, Infectious Diseases, Pseudomonas aeruginosa, OprF, Porin, MESH: Pseudomonas aeruginosa, Pseudomonas aeruginosa, MESH: Caco-2 Cells, Virulence Factors, Immunology, Biology, Microbiology, 03 medical and health sciences, Pyocyanin, Bacterial Proteins, MESH: Caenorhabditis elegans, medicine, Animals, Humans, Secretion, Pseudomonas Infections, Caenorhabditis elegans, 030304 developmental biology, MESH: Virulence Factors, MESH: Quinolones, MESH: Humans, 030306 microbiology, Gene Expression Regulation, Bacterial, Molecular Pathogenesis, Plant Leaves, chemistry, MESH: Chicory, Parasitology, Caco-2 Cells, Exotoxin
Abstract

OprF is a general outer membrane porin of Pseudomonas aeruginosa , a well-known human opportunistic pathogen associated with severe hospital-acquired sepsis and chronic lung infections of cystic fibrosis patients. A multiphenotypic approach, based on the comparative study of a wild-type strain of P. aeruginosa , its isogenic oprF mutant, and an oprF -complemented strain, showed that OprF is required for P. aeruginosa virulence. The absence of OprF results in impaired adhesion to animal cells, secretion of ExoT and ExoS toxins through the type III secretion system (T3SS), and production of the quorum-sensing-dependent virulence factors pyocyanin, elastase, lectin PA-1L, and exotoxin A. Accordingly, in the oprF mutant, production of the signal molecules N -(3-oxododecanoyl)- l -homoserine lactone and N -butanoyl- l -homoserine lactone was found to be reduced and delayed, respectively. Pseudomonas quinolone signal (PQS) production was decreased, while its precursor, 4-hydroxy-2-heptylquinoline (HHQ), accumulated in the cells. Taken together, these results show the involvement of OprF in P. aeruginosa virulence, at least partly through modulation of the quorum-sensing network. This is the first study showing a link between OprF, PQS synthesis, T3SS, and virulence factor production, providing novel insights into virulence expression.

Published
2011

26. Influence of growth temperature on cyclopeptides production and on adhesion behaviour in environmental strains of Pseudomonas fluorescens

Author

Anne Groboillot, Josselin Bodilis, Cécile Duclairoir-Poc, Thierry Meylheuc, MarcG.J. Feuilloley, Nicole Orange, Laure Taupin, ra Ngoya, Annabelle Merieau, Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Bioadhésion et Hygiène des Matériaux (BHM), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), and Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0303 health sciences, biology, Strain (chemistry), 030306 microbiology, Chemistry, Mutant, Biosurfactant, Pseudomonas fluorescens, Adhesion, Growth temperature, 16S ribosomal RNA, biology.organism_classification, Cyclolipopeptides, High-performance liquid chromatography, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Microbiology, 03 medical and health sciences, Secretion, Food science, Bacteria, 030304 developmental biology
Abstract

International audience; The present study deals with the influence of growth temperature on biosurfactant production and the adhesion process in the psychrotrophic species Pseudomonas fluorescens. We studied a strain panel composed of nine wild cyclolipopeptide (CLPs) producers and by two biosurfactant mutants. Where cyclolipopeptide production was characterized at either 8°C or 17°C, cyclolipopeptide production was highlighted by hemolytic and tensiometric methods. Their ionic charge was evaluated by a double diffusion test and their identification was made as amphisin- or viscosin- or viscosinamide-like biosurfactants by Reverse Phase- High Performance Liquid Chromatography- Mass Spectroscopy.This categorization was corroborated by the 16S rRNA phylogenetic study. In Pseudomonas fluorescens, the number and relative quantity of cyclolipopeptide produced and bacterial adhesion differed with the growth temperature. Seven new cyclolipopeptides were characterized, of which three belong to the viscosinamide family. Biosurfactant secretion is intensive at 17°C and the highest adhesion is obtained at a lower temperature (8°C). Cyclolipopeptides appeared to antagonize the adhesion process. Strain hydrophobicity was wholly independent of growth temperature and could not be correlated with the initial attachment of bacteria, which was thermoregulated. Our study demonstrates that bacterialadhesion is controlled by the growth temperature but not by cyclolipopeptides or cell hydrophobicity.

Published
2011

27. C-type natriuretic peptide modulates quorum sensing molecule and toxin production in Pseudomonas aeruginosa

Author

Nicole Orange, Eloïse Gerault, Karine Réhel, Alexis Bazire, Laure Taupin, Marc G. J. Feuilloley, Wilfried Veron, Christian Hulen, Julien Vieillard, Olivier Lesouhaitier, Anne-Sophie Blier, Franck Le Derf, Alain Dufour, Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Chimie Organique et Bioorganique : Réactivité et Analyse (COBRA), Institut Normand de Chimie Moléculaire Médicinale et Macromoléculaire (INC3M), Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie Organique Fine (IRCOF), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
MESH: Natriuretic Peptide, C-Type, MESH: Signal Transduction, Cyclic AMP Receptor Protein, MESH: ADP Ribose Transferases, MESH: Hydrogen Cyanide, medicine.disease_cause, MESH: Quorum Sensing, Ligases, chemistry.chemical_compound, Hydrogen Cyanide, MESH: Reverse Transcriptase Polymerase Chain Reaction, Natriuretic Peptide, Brain, Natriuretic peptide, Pseudomonas exotoxin, MESH: Animals, MESH: Natriuretic Peptide, Brain, MESH: Bacterial Proteins, ADP Ribose Transferases, 0303 health sciences, MESH: Gene Expression Regulation, Bacterial, biology, Reverse Transcriptase Polymerase Chain Reaction, Quorum Sensing, MESH: Transcription Factors, Brain natriuretic peptide, Standard, Biochemistry, MESH: Ligases, Pseudomonas aeruginosa, MESH: Pseudomonas aeruginosa, Signal Transduction, Pseudomonadaceae, MESH: 4-Quinolones, Virulence Factors, medicine.drug_class, Bacterial Toxins, Exotoxins, Virulence, Microbiology, 03 medical and health sciences, Pyocyanin, Bacterial Proteins, MESH: Caenorhabditis elegans, medicine, Animals, RNA, Messenger, Caenorhabditis elegans, 030304 developmental biology, MESH: RNA, Messenger, MESH: Virulence Factors, 4-Quinolones, 030306 microbiology, Natriuretic Peptide, C-Type, MESH: Cyclic AMP Receptor Protein, Gene Expression Regulation, Bacterial, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, MESH: Exotoxins, Quorum sensing, chemistry, MESH: Bacterial Toxins, Cell and Molecular Biology of Microbes, Pyocyanine, MESH: Pyocyanine, Transcription Factors
Abstract

Pseudomonas aeruginosa coordinates its virulence expression and establishment in the host in response to modification of its environment. During the infectious process, bacteria are exposed to and can detect eukaryotic products including hormones. It has been shown that P. aeruginosa is sensitive to natriuretic peptides, a family of eukaryotic hormones, through a cyclic nucleotide-dependent sensor system that modulates its cytotoxicity. We observed that pre-treatment of P. aeruginosa PAO1 with C-type natriuretic peptide (CNP) increases the capacity of the bacteria to kill Caenorhabditis elegans through diffusive toxin production. In contrast, brain natriuretic peptide (BNP) did not affect the capacity of the bacteria to kill C. elegans. The bacterial production of hydrogen cyanide (HCN) was enhanced by both BNP and CNP whereas the production of phenazine pyocyanin was strongly inhibited by CNP. The amount of 2-heptyl-4-quinolone (HHQ), a precursor to 2-heptyl-3-hydroxyl-4-quinolone (Pseudomonas quinolone signal; PQS), decreased after CNP treatment. The quantity of 2-nonyl-4-quinolone (HNQ), another quinolone which is synthesized from HHQ, was also reduced after CNP treatment. Conversely, both BNP and CNP significantly enhanced bacterial production of acylhomoserine lactone (AHL) [e.g. 3-oxo-dodecanoyl-homoserine lactone (3OC12-HSL) and butanoylhomoserine lactone (C4-HSL)]. These results correlate with an induction of lasI transcription 1 h after bacterial exposure to BNP or CNP. Concurrently, pre-treatment of P. aeruginosa PAO1 with either BNP or CNP enhanced PAO1 exotoxin A production, via a higher toxA mRNA level. At the same time, CNP led to elevated amounts of algC mRNA, indicating that algC is involved in C. elegans killing. Finally, we observed that in PAO1, Vfr protein is essential to the pro-virulent effect of CNP whereas the regulator PtxR supports only a part of the CNP pro-virulent activity. Taken together, these data reinforce the hypothesis that during infection natriuretic peptides, particularly CNP, could enhance the virulence of PAO1. This activity is relayed by Vfr and PtxR activation, and a general diagram of the virulence activation cascade involving AHL, HCN and exotoxin A is proposed.

Published
2011

28. The Major Outer Membrane Protein Oprf is Required for Rhamnolipid Production in Pseudomonas aeruginosa

Author

Emeline Bouffartigues, Gwendoline Gicquel, Alexis Bazire, Laurène Fito-Boncompte, Laure Taupin, Olivier Maillot, Anne Groboillot, Poc Duclairoir, C., Nicole Orange, Marc Feuilloley, Alain Dufour, sylvie CHEVALIER, Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Bazire, Alexis

Subjects
[SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

International audience; The OprF porin is the major outer membrane protein of bacteria belonging to the Pseudomonas genus, and is partially exposed on the cellular surface. A study based on the comparison between P. aeruginosa H103 and its oprFdeficient mutant led to the finding that the absence of OprF abolished swarming but not swimming and twitching motilities. These phenotypes were explained at least in part by the inability of the oprF mutant to produce biosurfactant rhamnolipids. The levels of mRNAs encoding the rhamnolipid biosynthetic enzymes RhlA and RhlB were strongly decreased in the absence of OprF, indicating that rhamnolipid production was impaired at the transcriptional level. We suggest that the presence of OprF in the outer membrane of P. aeruginosa is required for environments colonization, making thus OprF a serious target for limiting P. aeruginosa spreading in case of cystic fibrosis.

Published
2011

29. The Major Outer Membrane Protein Oprf is Required for Rhamnolipid Production in Pseudomonas aeruginosa

Author

Olivier Maillot, Sylvie Chevalier, Cécile Poc-Duclairoir, Gwendoline Gicquel, Laurène Fito-Boncompte, Alexis Bazire, Laure Taupin, Marc G. J. Feuilloley, Emeline Bouffartigues, Normandie Sécurité, Nicole Orange, Alain Dufour, and Anne Groboillot

Subjects
biology, Pseudomonas aeruginosa, Mutant, Pseudomonas, Rhamnolipid, Motility, biology.organism_classification, medicine.disease_cause, Microbiology, chemistry.chemical_compound, chemistry, Porin, medicine, Bacterial outer membrane, Bacteria
Abstract

The OprF porin is the major outer membrane protein of bacteria belonging to the Pseudomonas genus, and is partially exposed on the cellular surface. A study based on the comparison between P. aeruginosa H103 and its oprFdeficient mutant led to the finding that the absence of OprF abolished swarming but not swimming and twitching motilities. These phenotypes were explained at least in part by the inability of the oprF mutant to produce biosurfactant rhamnolipids. The levels of mRNAs encoding the rhamnolipid biosynthetic enzymes RhlA and RhlB were strongly decreased in the absence of OprF, indicating that rhamnolipid production was impaired at the transcriptional level. We suggest that the presence of OprF in the outer membrane of P. aeruginosa is required for environments colonization, making thus OprF a serious target for limiting P. aeruginosa spreading in case of cystic fibrosis.

Published
2011

30. A HPLC-UV method for the determination of angiotensin I-converting enzyme (ACE) inhibitory activity

Author

Karine Réhel, Dominique Haras, Laure Taupin, Véronique Lahogue, Patrick Allaume, Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Bazire, Alexis

Subjects
chemistry.chemical_classification, Chromatography, Chemistry, 010401 analytical chemistry, Size-exclusion chromatography, Substrate (chemistry), Peptide, Captopril, 04 agricultural and veterinary sciences, General Medicine, 040401 food science, 01 natural sciences, High-performance liquid chromatography, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Hydrolysate, 0104 chemical sciences, Analytical Chemistry, Hydrolysis, Fish hydrolysate, 0404 agricultural biotechnology, medicine, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, ComputingMilieux_MISCELLANEOUS, Food Science, medicine.drug
Abstract

To determine the angiotensin-converting enzyme (ACE) inhibitory activity of a fish hydrolysate, different methods were tested. Finally, a sensitive, extraction-free HPLC method using N-(3-[2-furylacryloyl)-Phe-Gly-Gly (FAPGG) as substrate was preferred. This method relies on the UV-titration of the peptide 2-furylacryloyl- l -Phe (FAP) resulting from the hydrolysis of the FAPGG after a chromatographic separation on a reverse phase column. The experimental conditions (enzyme/substrate ratio, incubation time, NaCl concentration) were optimised for linearity, sensitivity and precision. The assay was adequate for the study of ACE inhibition by Captopril, used as reference, and several peptides. Captopril and the fish hydrolysate had IC50 values, respectively of 0.19 ng and 43 μg with standard deviations of 0.09 ng and 5 μg. Afterwards, the determination of the Hill coefficient sustained the hypothesis that active peptides present in the fish hydrolysate were low-molecular weight molecules. This result was confirmed by the activity measurement of the fish hydrolysate fractions obtained by gel filtration.

Published
2010

31. Effects of Osmotic Stress on Rhamnolipid Synthesis and Time-Course Production of Cell-To-Cell Signal Molecules by Pseudomonas aeruginosa

Author

Alexis Bazire, Farès Diab, Sophie Rodrigues, Laure Taupin, Alain Dufour, Mohamed Jebbar, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de microbiologie des environnements extrêmophiles (LM2E), Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), and Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Osmotic stress, Osmotic shock, Biology, Article, 03 medical and health sciences, chemistry.chemical_compound, Betaine, Biosynthesis, Homoserine lactone, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, General Immunology and Microbiology, 030306 microbiology, Rhamnolipid, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Quorum sensing, Enzyme, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, chemistry, Biochemistry, Glycine, Pseudomonas Quinolone Signal, Pseudomonas aeruginosa, Osmoprotectant
Abstract

Equipe OB devenue Equipe Dualité ou Universalité de l'Adaptation lors d'un Stress (DUALS); International audience; Biosynthesis of biosurfactant rhamnolipids by Pseudomonas aeruginosa depends on two hierarchical quorum sensing systems, LasRI and RhlRI, which synthesize and sense the signal molecules N-(3-oxododecanoyl)-L-homoserine lactone (3OC(12)-HSL) and N-butyryl-L-homoserine lactone (C(4)-HSL), respectively. The Pseudomonas Quinolone Signal (PQS) is a third cell-to-cell signal molecule connecting these two systems, and its precursor, 2-heptyl-4-quinolone (HHQ), also constitutes a signal. The chronology of the production of signal molecules and rhamnolipids was determined during growth in PPGAS medium. Hyperosmotic condition (0.5 M NaCl) moderately affected growth, and led to intra-cellular accumulation of compatible solutes. Production of signal molecules was delayed and their highest concentrations were 2.5 to 5 fold lower than in NaCl-free PPGAS, except for HHQ, the highest concentration of which was increased. The presence of NaCl prevented rhamnolipid synthesis. When the osmoprotectant glycine betaine was added to PPGAS/NaCl medium, it was imported by the cells without being metabolized. This did not improve growth, but reestablished the time-courses of HSL and HHQ accumulation and fully or partially restored the HSL and PQS levels. It also partially restored rhamnolipid production. Quantification of mRNAs encoding enzymes involved in HSL, PQS, and rhamnolipid biosyntheses confirmed the effect of hyperosmotic stress and glycine betaine at the gene expression level.

Published
2009

32. In Planta Biocontrol of Pectobacterium atrosepticum by Rhodococcus erythropolis Involves Silencing of Pathogen Communication by the Rhodococcal Gamma-Lactone Catabolic Pathway

Author

Jean-François Burini, Nicole Orange, Alain Dufour, Laure Taupin, Marc G. J. Feuilloley, Lily Mijouin, Dorian Bergeau, Alexandre Crépin, Xavier Latour, Corinne Barbey, Asma Ouchiha, Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Microbiologie du Froid – Signaux et Micro-Environnement (LMDF-SME), Université de Rouen Normandie (UNIROUEN), and Normandie Université (NU)-Normandie Université (NU)

Subjects
Pectobacterium, lcsh:Medicine, Plant Science, Acyl-Butyrolactones, Mass Spectrometry, chemistry.chemical_compound, Plant Microbiology, Vegetables, Lactonase, Gram Negative, Rhodococcus, lcsh:Science, Pathogen, Chromatography, High Pressure Liquid, 0303 health sciences, Microscopy, Confocal, Multidisciplinary, biology, Quorum Sensing, food and beverages, Agriculture, Plants, Bacterial Pathogens, Plant Tubers, Research Article, Plant Pathogens, Homoserine, Virulence, Crops, Horticulture, Microbiology, 03 medical and health sciences, Bacterial Proteins, Microbial Control, Escherichia coli, Biology, Pectobacterium atrosepticum, Solanum tuberosum, 030304 developmental biology, 030306 microbiology, lcsh:R, Crop Diseases, Plant Pathology, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Sustainable Agriculture, Agronomy, Quorum sensing, chemistry, biology.protein, lcsh:Q, Heterologous expression
Abstract

International audience; : The virulence of numerous Gram-negative bacteria is under the control of a quorum sensing process based on synthesis and perception of N-acyl homoserine lactones. Rhodococcus erythropolis, a Gram-positive bacterium, has recently been proposed as a biocontrol agent for plant protection against soft-rot bacteria, including Pectobacterium. Here, we show that the γ-lactone catabolic pathway of R. erythropolis disrupts Pectobacterium communication and prevents plant soft-rot. We report the first characterization and demonstration of N-acyl homoserine lactone quenching in planta. In particular, we describe the transcription of the R. erythropolis lactonase gene, encoding the key enzyme of this pathway, and the subsequent lactone breakdown. The role of this catabolic pathway in biocontrol activity was confirmed by deletion of the lactonase gene from R. erythropolis and also its heterologous expression in Escherichia coli. The γ-lactone catabolic pathway is induced by pathogen communication rather than by pathogen invasion. This is thus a novel and unusual biocontrol pathway, differing from those previously described as protecting plants from phytopathogens. These findings also suggest the existence of an additional pathway contributing to plant protection.

Published
2013

33. New key players in Pseudomonas aeruginosa tobramycin-enhanced biofilm formation

Author

Ali Tahrioui, Rachel Duchesne, Emeline Bouffartigues, Sophie Rodrigues, Olivier Maillot, Damien Tortuel, Julie Hardouin, Laure Taupin, Marie-Christine Groleau, Alain Dufour, Éric Déziel, Marc Feuilloley, Nicole Orange, Olivier Lesouhaitier, Pierre Cornelis, sylvie CHEVALIER, Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Polymères Biopolymères Surfaces (PBS), Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Institut Normand de Chimie Moléculaire Médicinale et Macromoléculaire (INC3M), Institut de Chimie du CNRS (INC)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Armand Frappier (INRS-IAF), and Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP)

Subjects
[SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BBM.MN]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular Networks [q-bio.MN], biochemical phenomena, metabolism, and nutrition, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

International audience; Introduction: Biofilms are structured microbial communities that are the leading cause of numerous chronic infections which are difficult to eradicate. Within the lungs of individuals with cystic fibrosis, Pseudomonas aeruginosa causes persistent biofilm infection that is commonly treated with aminoglycoside antibiotics such as tobramycin. However, exposure to sublethal concentrations of the aminoglycoside tobramycin were previously shown to increase biofilm formation by P. aeruginosa.Hypothesis and aims: In the current study, we sought to elucidate potential adaptive mechanisms shaping the tobramycin-enhanced biofilm formation in P. aeruginosa.Methodology: We combined confocal laser scanning microscope analyses, proteomics profiling, gene expression assays and phenotypic studies to unravel P. aeruginosa potential adaptive mechanisms in response to tobramycin exposure during biofilm growth.Results: We show that the modified biofilm architecture is related at least in part to increased extracellular DNA (eDNA) release, most likely as a result of biofilm cell death. Furthermore, the activity of quorum sensing (QS) systems was increased, leading to higher production of QS molecules. We also demonstrate upon tobramycin exposure an increase in expression of the small RNAs PrrF1 and PrrF2, known for promoting 4-hydroxy-2- alkylquinolines production, as well as expression of iron uptake systems. Remarkably, biofilm biovolumes and eDNA relative abundances in pqs and prrF1,F2 mutant strains decrease in the presence of tobramycin.Conclusion: Our findings offer experimental evidences for a potential adaptive mechanism linking PrrF1/F2 sRNAs, QS signaling, biofilm cell death, eDNA release, and tobramycin- enhanced biofilm formation in P. aeruginosa.

Catalog

Books, media, physical & digital resources
See catalog results