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6 results on '"Julien Cayron"'

1. Role of AcrAB-TolC multidrug efflux pump in drug-resistance acquisition by plasmid transfer

Author

Christian Lesterlin, Julien Cayron, Adeline Page, Frédéric Delolme, Sophie Nolivos, Annick Dedieu, Microbiologie moléculaire et biochimie structurale / Molecular Microbiology and Structural Biochemistry (MMSB), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), and Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.OT]Life Sciences [q-bio]/Other [q-bio.OT], Tetracycline, DNA, Single-Stranded, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Drug resistance, medicine.disease_cause, Antiporters, Bacterial genetics, F Factor, 03 medical and health sciences, Plasmid, Bacterial Proteins, Drug Resistance, Multiple, Bacterial, [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Escherichia coli, Protein biosynthesis, medicine, [CHIM]Chemical Sciences, 030304 developmental biology, Microscopy, 0303 health sciences, Multidisciplinary, 030306 microbiology, Chemistry, Escherichia coli Proteins, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, biochemical phenomena, metabolism, and nutrition, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Anti-Bacterial Agents, Cell biology, Conjugation, Genetic, Protein Biosynthesis, Horizontal gene transfer, Efflux, Carrier Proteins, medicine.drug
Abstract

A race against time Clinically relevant antimicrobial resistance is largely spread via plasmids that disperse among bacteria during conjugation. How quickly can a resistance gene be expressed after transfer? In susceptible bacterial cells, tetracycline should inhibit protein synthesis, including from the plasmid-transferred resistance gene tetA . Unexpectedly, Nolivos et al. found that TetA can be expressed despite the presence of tetracycline (see the Perspective by Povolo and Ackermann). Immediately after plasmid transfer into a cell, TetA synthesis starts because its repressor is slow to be expressed. In addition, the ubiquitous xenobiotic efflux pump AcrAB-TolC buys time for TetA translation by keeping tetracycline concentration below toxic levels. Science , this issue p. 778 ; see also p. 737

Published
2019

2. Bacterial filament division dynamics allows rapid post-stress cell proliferation

Author

Christian Lesterlin, Julien Cayron, and Dedieu A

Subjects
Chromosome segregation, Protein filament, medicine.anatomical_structure, Filamentation, Cell division, Chemistry, Min System, Cell growth, Cell, medicine, Nucleoid, Cell biology
Abstract

Many bacterial species grow into filaments under stress conditions. Initially regarded as an indicator of cell death, filamentation is now proposed to be a transient morphological change that improves bacterial survival in hostile environments. However, the mechanism of filament recovery remains poorly characterized. Using real-time microscopy in live-cells, we analysed the fate of filamentousEscherichia coliinduced by antibiotic-mediated specific inhibition of cell division, or by UV-induced DNA-damage that additionally perturbs chromosome segregation. Both filament types recover by successive and accelerated rounds of divisions, which are preferentially positioned asymmetrically at the tip of the cell by the Min system. Such division dynamics allows the rapid production of daughter cells with normal size, which DNA content depends on the progression of chromosome segregation prior to division. In most filaments, nucleoid segregation precedes tip-division, which produces nucleated daughter cells that resume normal growth. However, when segregation is deficient, tip-division occurs in the absence of DNA and produces anucleated cells. These findings uncover the mechanism by which bacterial filamentation allows efficient post-stress cell proliferation.One Sentence SummaryBacterial filaments recover by successive, frequent and Min-dependent asymmetric tip-divisions that rapidly produce multiple daughter cells with normal size and viability

Published
2020

3. Original sequence divergence among Pseudomonas putida CadRs drive specificity

Author

Julien Cayron, Géraldine Effantin, Agnès Rodrigue, Elsa Prudent, 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), Trafic et signalisation membranaires chez les bactéries (MTSB), 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), Institut Hospitalier Universitaire Méditerranée Infection (IHU Marseille), Microbes évolution phylogénie et infections (MEPHI), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU), ANR-11-ECOT-0009,COMBITOX,COnception d'un instrument pour la Mesure BIologique multiparamètrique en continu de TOXiques(2011), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Amino Acid Motifs, chemistry.chemical_element, Microbiology, Substrate Specificity, Metal, Metalloregulatory Protein, 03 medical and health sciences, Bacterial Proteins, Protein Domains, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Mercury detection, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Molecular Biology, Gene, 030304 developmental biology, Cadmium resistance, 0303 health sciences, Cadmium, biology, Pseudomonas putida, 030306 microbiology, Genetic Variation, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Gene Expression Regulation, Bacterial, Mercury, General Medicine, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Lead, Biochemistry, chemistry, Multigene Family, visual_art, Mutation, visual_art.visual_art_medium, Bacteria
Abstract

International audience; Bacteria, especially those living in soils, are in constant contact with metals. Transition metals like Fe or Zn, are required for proper growth. Some other metals like Cd or Hg are only toxic. Several systems exist to detoxify cells when these metals are present in concentrations harmful to biological systems. The expression of these systems is under control of specialized regulatory proteins able to detect metals and to regulate cognate detoxifying systems. In this work we report on the characterisation of the metallo-regulator CadR from P. putida KT2440. By using gene reporter assays, we investigated the repertoire of metals detected by CadR. We show that CadR is much more responsive to Hg than to Cd, as compared to CadR from P. putida 06909. CadR from P. putida KT2440 differs in only 3 amino-acids in its metal-binding domain with respect to CadR from P. putida 06909. We show that these residues are important determinants of metal selectivity by engineering a modified CadR.

Published
2020

4. Identification of a Contact-Dependent Growth Inhibition (CDI) System That Reduces Biofilm Formation and Host Cell Adhesion of Acinetobacter baumannii DSM30011 Strain

Author

Morgane Roussin, Sedera Rabarioelina, Laurence Cluzeau, Julien Cayron, Christian Lesterlin, Suzana P. Salcedo, Sarah Bigot, Microbiologie moléculaire et biochimie structurale / Molecular Microbiology and Structural Biochemistry (MMSB), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
Microbiology (medical), lcsh:QR1-502, medicine.disease_cause, Microbiology, biofilm, lcsh:Microbiology, 03 medical and health sciences, chemistry.chemical_compound, medicine, Escherichia coli, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, Strain (chemistry), 030306 microbiology, contact-dependent growth inhibition, Biofilm, biology.organism_classification, Phenotype, Acinetobacter baumannii, cell adhesion ability, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, chemistry, Growth inhibition, Acinectobacter baumannii, Bacteria, DNA, type V secretion system
Abstract

Acinetobacter baumannii is a multidrug-resistant nosocomial opportunistic pathogen that is becoming a major health threat worldwide. In this study, we have focused on the A. baumannii DSM30011 strain, an environmental isolate that retains many virulence-associated traits. We found that its genome contains two loci encoding for contact-dependent growth inhibition (CDI) systems. These systems serve to kill or inhibit the growth of non-sibling bacteria by delivering toxins into the cytoplasm of target cells, thereby conferring the host strain a significant competitive advantage. We show that one of the two toxins functions as a DNA-damaging enzyme, capable of inducing DNA double-stranded breaks to the chromosome of Escherichia coli strain. The second toxin has unknown catalytic activity but stops the growth of E. coli without bactericidal effect. In our conditions, only one of the CDI systems was highly expressed in the A. baumannii DSM30011 strain and was found to mediate interbacterial competition. Surprisingly, the absence of this CDI system promotes adhesion of A. baumannii DSM30011 to both abiotic and biotic surfaces, a phenotype that differs from previously described CDI systems. Our results suggest that a specific regulation mediated by this A. baumannii DSM30011 CDI system may result in changes in bacterial physiology that repress host cell adhesion and biofilm formation.

Published
2019

5. Pushing the limits of nickel detection to nanomolar range using a set of engineered bioluminescent Escherichia coli

Author

Camille Escoffier, Agnès Rodrigue, Marie-Andrée Mandrand-Berthelot, Daniel Garcia, David Pignol, Julien Cayron, Erwan Gueguen, Elsa Prudent, 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), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Trafic et signalisation membranaires chez les bactéries (MTSB), 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), Microbiologie Environnementale et Moléculaire (MEM), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT), ANR-11-ECOT-0009,COMBITOX,COnception d'un instrument pour la Mesure BIologique multiparamètrique en continu de TOXiques(2011), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and 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)

Subjects
0301 basic medicine, Health, Toxicology and Mutagenesis, chemistry.chemical_element, Biosensing Techniques, macromolecular substances, Biology, medicine.disease_cause, Sensitivity and Specificity, 03 medical and health sciences, Genes, Reporter, Nickel, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Escherichia coli, medicine, Environmental Chemistry, Bioluminescence, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Promoter Regions, Genetic, Detection limit, Reporter gene, Escherichia coli Proteins, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Gene Expression Regulation, Bacterial, General Medicine, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Pollution, Molecular biology, Repressor Proteins, Luminescent Proteins, 030104 developmental biology, Biochemistry, chemistry, Regulatory circuit, Efflux, Biosensor
Abstract

International audience; The detection of nickel in water is of great importance due to its harmfulness for living organism. A way to detect Ni is the use of whole-cell biosensors. The aim of the present work was to build a light-emitting bacterial biosensor for the detection of Ni with high specificity and low detection limit properties. For that purpose, the regulatory circuit implemented relied on the RcnR Ni/Co metallo-regulator and its rcnA natural target promoter fused to the lux reporter genes. To convert RcnR to specifically detect Ni, several mutations were tested and the C35A retained. Deleting the Ni efflux pump rcnA and introducing genes encoding several Ni-uptake systems lowered the detection thresholds. When these constructs were assayed in several Escherichia coli strains, it appeared that the detection thresholds were highly variable. The TD2158 wild-type E. coli gave rise to a biosensor ten times more active and sensitive than its W3110 E. coli K12 equivalent. This biosensor was able to confidently detect Ni concentrations as little as 80 nM (4.7 μg l −1), which makes its use compatible with the norms governing the drinking water quality.

Published
2015

6. Bacterial host and reporter gene optimization for genetically encoded whole cell biosensors

Author

Nicolas Ginet, Elodie C. T. Descamps, Géraldine Adryanczyk-Perrier, Louis Dumas, Agnès Rodrigue, David Pignol, Arjan de Groot, Julien Cayron, Elsa Prudent, Sandra Prévéral, Camille Escoffier, Manon Ricquebourg, Catherine Brutesco, Daniel Garcia, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Microbiologie Environnementale et Moléculaire (MEM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), 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), Bioénergie et Microalgues (EBM), Trafic et signalisation membranaires chez les bactéries (MTSB), 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), ANR-11-ECOT-0009,COMBITOX,COnception d'un instrument pour la Mesure BIologique multiparamètrique en continu de TOXiques(2011), Biologie végétale et microbiologie environnementale - UMR7265 ( BVME ), Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Aix Marseille Université ( AMU ), Ecologie microbienne ( EM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Vétérinaire de Lyon ( ENVL ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS ), Centre Sciences des Processus Industriels et Naturels ( SPIN-ENSMSE ), École des Mines de Saint-Étienne ( Mines Saint-Étienne MSE ), Institut Mines-Télécom [Paris]-Institut Mines-Télécom [Paris], Département GéoSciences et Environnement ( GSE-ENSMSE ), Institut Mines-Télécom [Paris]-Institut Mines-Télécom [Paris]-SPIN, Environnement Ville Société ( EVS ), École normale supérieure - Lyon ( ENS Lyon ) -Université Lumière - Lyon 2 ( UL2 ) -Université Jean Moulin - Lyon III-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -École Nationale des Travaux Publics de l'État ( ENTPE ) -Ecole Nationale Supérieure des Mines de Saint-Etienne-École nationale supérieure d'architecture de Lyon ( ENSAL ) -Centre National de la Recherche Scientifique ( CNRS ), 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 ), Laboratoire de chimie bactérienne ( LCB ), Aix Marseille Université ( AMU ) -Centre National de la Recherche Scientifique ( CNRS ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, and Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon)

Subjects
0301 basic medicine, Arsenites, Health, Toxicology and Mutagenesis, Biosensing Techniques, macromolecular substances, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, 010501 environmental sciences, medicine.disease_cause, 01 natural sciences, Gene Expression Regulation, Enzymologic, Microbiology, [ SDE ] Environmental Sciences, 03 medical and health sciences, chemistry.chemical_compound, Genes, Reporter, Metals, Heavy, Escherichia coli, medicine, Environmental Chemistry, Bioluminescence, Deinococcus, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Promoter Regions, Genetic, [ SDV.BBM ] Life Sciences [q-bio]/Biochemistry, Molecular Biology, 0105 earth and related environmental sciences, Arsenite, Reporter gene, [SDV.GEN]Life Sciences [q-bio]/Genetics, biology, [ SDV.BC ] Life Sciences [q-bio]/Cellular Biology, technology, industry, and agriculture, Water, Gene Expression Regulation, Bacterial, General Medicine, biology.organism_classification, Deinococcus deserti, Pollution, Luciferases, Bacterial, 030104 developmental biology, chemistry, Biochemistry, [SDE]Environmental Sciences, [ SDV.GEN ] Life Sciences [q-bio]/Genetics, Biosensor, Water Pollutants, Chemical, Bacteria, Environmental Monitoring
Abstract

International audience; Whole-cell biosensors based on reporter genes allow detection of toxic metals in water with high selectivity and sensitivity under laboratory conditions; nevertheless, their transfer to a commercial inline water analyzer requires specific adaptation and optimization to field conditions as well as economical considerations. We focused here on both the influence of the bacterial host and the choice of the reporter gene by following the responses of global toxicity biosensors based on constitutive bacterial promoters as well as arsenite biosensors based on the arsenite-inducible P-ars promoter. We observed important variations of the bioluminescence emission levels in five different Escherichia coli strains harboring two different lux-based biosensors, suggesting that the best host strain has to be empirically selected for each new biosensor under construction. We also investigated the bioluminescence reporter gene system transferred into Deinococcus deserti, an environmental, desiccation- and radiation-tolerant bacterium that would reduce the manufacturing costs of bacterial biosensors for commercial water analyzers and open the field of biodetection in radioactive environments. We thus successfully obtained a cell survival biosensor and a metal biosensor able to detect a concentration as low as 100 nM of arsenite in D. deserti. We demonstrated that the arsenite biosensor resisted desiccation and remained functional after 7 days stored in air-dried D. deserti cells. We also report here the use of a new near-infrared (NIR) fluorescent reporter candidate, a bacteriophytochrome from the magnetotactic bacterium Magnetospirillum magneticum AMB-1, which showed a NIR fluorescent signal that remained optimal despite increasing sample turbidity, while in similar conditions, a drastic loss of the lux-based biosensors signal was observed.

Published
2017

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