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1. Tracking Animal Reservoirs of Pathogenic Leptospira: The Right Test for the Right Claim

Author

Koussay Dellagi, Patrick Mavingui, Pablo Tortosa, Yann Gomard, Steve Michael Goodman, Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-IRD-Centre National de la Recherche Scientifique (CNRS), Direction Internationale de l'Institut Pasteur, Institut Pasteur [Paris] (IP), Association Vahatra [Antananarivo, Madagascar], Field Museum of Natural History [Chicago, USA], The sampling of Mormopterus acetabulosus on Mauritius was supported by a grant from European Research Development Fund (ERDF) 'Pathogènes associés à la Faune Sauvage Océan Indien' #31189. Original serological data presented in this paper were obtained under a grant from ERDF known as InterregV ECOSPIR 'Eco-épidemiologie des leptospires endémiques de l’Océan Indien: des bactéries à risque pour les populations humaines?' (number RE6875)., Tortosa, Pablo, Centre National de la Recherche Scientifique (CNRS)-IRD-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de La Réunion (UR), and Institut Pasteur [Paris]

Subjects
Leptospira, 030231 tropical medicine, Zoology, Context (language use), Biology, Article, Microbiology, Serology, 03 medical and health sciences, 0302 clinical medicine, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Direct agglutination test, medicine, [SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology, One Health, 030304 developmental biology, 0303 health sciences, animal reservoir, MAT, [SDV.BA.MVSA]Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health, General Immunology and Microbiology, 030306 microbiology, Zoonosis, Public Health, Environmental and Occupational Health, [SDV.BA.MVSA] Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health, Gold standard (test), medicine.disease, biology.organism_classification, Leptospirosis, 3. Good health, Chronic infection, Infectious Diseases, [SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie, [SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Medicine, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, [SDV.MP.PAR] Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology
Abstract

Leptospirosis, caused by a pathogenic Leptospira bacteria, is the most prevalent zoonosis worldwide and in this context has been extensively investigated through a One Health framework. Diagnosis of human leptospirosis includes molecular and serological tools, with serological Microscopic Agglutination Test (MAT) still being considered as a gold standard. Mammals considered as biological reservoirs include species or populations that are able to maintain chronic infection and shed the bacteria via their urine in the environment. Leptospira bacteria are often investigated using the same diagnosis tool, serological MAT. However, MAT testing of putative animal reservoirs can lead to mis-interpretations as it can signal previous infection and not necessarily bring in robust information regarding the capacity of such sero-positive animals to maintain chronic infection. We use previously published data and present new results on introduced and endemic small mammals to show that MAT should not be used for the identification of reservoirs. By contrast, serological data are informative on the level of exposure of animals occupying a specific environment. Finally, we present a sequential methodology to investigate human leptospirosis in a One Health framework that associates molecular detection in humans and animals, together with MAT of human samples using Leptospira isolates obtained from reservoir animals occurring in the same environment.

Published
2021
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2. Molecular Mimicry: a Paradigm of Host-Microbe Coevolution Illustrated by Legionella

Author

Silke Schmidt, Carmen Buchrieser, Sonia Mondino, Biologie des Bactéries intracellulaires - Biology of Intracellular Bacteria, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Collège doctoral [Sorbonne universités], Sorbonne Université (SU), Work in the C.B. laboratory is financed by the Institut Pasteur, and funding has been received from the French Government (grants ANR-10-LABX-62-IBEID and ANR-15-CE17-0014-03 to C.B.) and the Fondation de la Recherche Médicale (grant EQU201903007847 to C.B.). S.S. is a scholar in the Pasteur-Paris University (PPU) international Ph.D. program and received a stipend from the Institut Pasteur., S.M., S.S., and C.B. contributed to the conception and the design of the minireview. S.M. and S.S. researched and wrote the paper. C.B. directed and contributed to the writing of the manuscript., ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), ANR-15-CE17-0014,ProgLegio,Biomarqueurs bactériens et humains d'intérêt pronostic pour les légionelloses sévères(2015), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), and Collège Doctoral

Subjects
Virulence Factors, Legionella, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Computational biology, medicine.disease_cause, Microbiology, Legionella pneumophila, Genome, Host-Microbe Biology, Biological Coevolution, 03 medical and health sciences, Bacterial Proteins, Virology, medicine, Humans, host-pathogen interactions, molecular mimicry, Gene, Coevolution, 030304 developmental biology, 0303 health sciences, Host Microbial Interactions, biology, 030306 microbiology, Host (biology), biology.organism_classification, eukaryotic-like proteins, QR1-502, Molecular mimicry, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, amoeba-resistant bacteria, Identification (biology), Minireview, Genome, Bacterial, Function (biology)
Abstract

Through coevolution with host cells, microorganisms have acquired mechanisms to avoid the detection by the host surveillance system and to use the cell’s supplies to establish themselves. Indeed, certain pathogens have evolved proteins that imitate specific eukaryotic cell proteins, allowing them to manipulate host pathways, a phenomenon termed molecular mimicry. Bacterial “eukaryotic-like proteins” are a remarkable example of molecular mimicry. They are defined as proteins that strongly resemble eukaryotic proteins or that carry domains that are predominantly present in eukaryotes and that are generally absent from prokaryotes., Through coevolution with host cells, microorganisms have acquired mechanisms to avoid the detection by the host surveillance system and to use the cell’s supplies to establish themselves. Indeed, certain pathogens have evolved proteins that imitate specific eukaryotic cell proteins, allowing them to manipulate host pathways, a phenomenon termed molecular mimicry. Bacterial “eukaryotic-like proteins” are a remarkable example of molecular mimicry. They are defined as proteins that strongly resemble eukaryotic proteins or that carry domains that are predominantly present in eukaryotes and that are generally absent from prokaryotes. The widest diversity of eukaryotic-like proteins known to date can be found in members of the bacterial genus Legionella, some of which cause a severe pneumonia in humans. The characterization of a number of these proteins shed light on their importance during infection. The subsequent identification of eukaryotic-like genes in the genomes of other amoeba-associated bacteria and bacterial symbionts suggested that eukaryotic-like proteins are a common means of bacterial evasion and communication, shaped by the continuous interactions between bacteria and their protozoan hosts. In this review, we discuss the concept of molecular mimicry using Legionella as an example and show that eukaryotic-like proteins effectively manipulate host cell pathways. The study of the function and evolution of such proteins is an exciting field of research that is leading us toward a better understanding of the complex world of bacterium-host interactions. Ultimately, this knowledge will teach us how host pathways are manipulated and how infections may possibly be tackled.

Published
2020
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3. <scp>B</scp>acillus subtilisserine/threonine protein kinase<scp>YabT</scp>is involved in spore development via phosphorylation of a bacterial recombinase

Author

Céline Henry, Ivan Mijakovic, Alain Trubuil, Lei Shi, Magali Ventroux, Marie-Françoise Noirot-Gros, Ahasanul Kobir, Vladimir Bidnenko, Nathalie Pigeonneau, MICrobiologie de l'ALImentation au Service de la Santé (MICALIS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Unité de recherche Mathématiques et Informatique Appliquées (MIA), Institut National de la Recherche Agronomique (INRA), and This research was supported by the grant from the Institut National de la Recherche Agronomique to I. M. We are grateful to Stephanie Marsin (CEA, France) for the anti-RecA antiserum. We would like to dedicate the paper to the memory of Mirjana Petranovic, for her contribution to the field of bacterial DNA recombination.

Subjects
Spores, [SDV.SA]Life Sciences [q-bio]/Agricultural sciences, [SDV]Life Sciences [q-bio], Serine threonine protein kinase, Bacillus subtilis, Protein Serine-Threonine Kinases, Biology, Microbiology, AKT3, Serine, 03 medical and health sciences, YabT, Nucleoid, Phosphorylation, Molecular Biology, Research Articles, 030304 developmental biology, Serine/threonine-specific protein kinase, 0303 health sciences, Protein-Serine-Threonine Kinases, 030306 microbiology, biology.organism_classification, Rec A Recombinases, Biochemistry, bacteria, Protein Processing, Post-Translational, Gene Deletion
Abstract

International audience; We characterized YabT, a serine/threonine kinase of the Hanks family, from Bacillus subtilis. YabT is a putative transmembrane kinase that lacks the canonical extracellular signal receptor domain. We demonstrate that YabT possesses a DNA-binding motif essential for its activation. In vivoYabT is expressed during sporulation and localizes to the asymmetric septum. Cells devoid of YabT sporulate more slowly and exhibit reduced resistance to DNA damage during sporulation. We established that YabT phosphorylates DNA-recombinase RecA at the residue serine 2. A non-phosphorylatable mutant of RecA exhibits the same phenotype as the yabT mutant, and a phosphomimetic mutant of RecA complements yabT, suggesting that YabT acts via RecA phosphorylation in vivo. During spore development, phosphorylation facilitates the formation of transient and mobile RecA foci that exhibit a scanning-like movement associated to the nucleoid in the mother cell. In some cells these foci persist at the end of spore development. We show that persistent RecA foci, which presumably coincide with irreparable lesions, are mutually exclusive with the completion of spore morphogenesis. Our results highlight similarities between the bacterial serine/threonine kinase YabT and eukaryal kinases C-Abl and Mec1, which are also activated by DNA, and phosphorylate proteins involved in DNA damage repair.

Published
2013
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4. Neutrophil Extracellular Traps are Involved in the Innate Immune Response to Infection with Leptospira

Author

Emilia Scharrig, María Florencia Ferrer, Agostina Carestia, Mathieu Picardeau, Maia Cédola, Ricardo Martín Gómez, Mirta Schattner, Gabriela Pretre, Ricardo Drut, CCT La Plata-CONICET-Facultad de Ciencias Veterinarias [La Plata, PBA, Argentine], Universidad Nacional de la Plata [Argentine] (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET), Children Hospital 'Superiora Sor María Ludovica' LA PLATA, Biologie des Spirochètes / Biology of Spirochetes, Institut Pasteur [Paris], This work was supported by PICTs grant 12-0434 (RMG) and 11-733 (MS) from ANPCyT. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript., Conceived and designed the experiments: MP MS RMG. Performed the experiments: ES AC MFF GP. Analyzed the data: MC RD. Contributed reagents/materials/analysis tools: MP. Wrote the paper: MS RMG., and Institut Pasteur [Paris] (IP)

Subjects
Male, lcsh:Arctic medicine. Tropical medicine, Neutrophils, lcsh:RC955-962, [SDV]Life Sciences [q-bio], Inflammation, Extracellular Traps, Microbiology, purl.org/becyt/ford/1 [https], Ciencias Biológicas, Mice, 03 medical and health sciences, neutrophils, Immunity, In vivo, Leptospira, medicine, Animals, Humans, leptospirosis, Leptospirosis, purl.org/becyt/ford/1.6 [https], Ciencias Exactas, 030304 developmental biology, 0303 health sciences, Innate immune system, biology, 030306 microbiology, lcsh:Public aspects of medicine, Public Health, Environmental and Occupational Health, lcsh:RA1-1270, Nets, Neutrophil extracellular traps, biology.organism_classification, Immunity, Innate, 3. Good health, Mice, Inbred C57BL, Infectious Diseases, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, medicine.symptom, Leptospira interrogans, Virología, Ex vivo, CIENCIAS NATURALES Y EXACTAS, Research Article
Abstract

NETosis is a process by which neutrophils extrude their DNA together with bactericidal proteins that trap and/or kill pathogens. In the present study, we evaluated the ability of Leptospira spp. to induce NETosis using human ex vivo and murine in vivo models. Microscopy and fluorometric studies showed that incubation of human neutrophils with Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 (LIC) resulted in the release of DNA extracellular traps (NETs). The bacteria number, pathogenicity and viability were relevant factors for induction of NETs, but bacteria motility was not. Entrapment of LIC in the NETs resulted in LIC death; however, pathogenic but not saprophytic Leptospira sp. exerted nuclease activity and degraded DNA. Mice infected with LIC showed circulating NETs after 2 days post-infection (dpi). Depletion of neutrophils with mAb1A8 significantly reduced the amount of intravascular NETs in LIC-infected mice, increasing bacteremia at 3 dpi. Although there was a low bacterial burden, scarce neutrophils and an absence of inflammation in the early stages of infection in the kidney and liver, at the beginning of the leptospiruric phase, the bacterial burden was significantly higher in kidneys of neutrophil-depleted-mice compared to non-depleted and infected mice. Surprisingly, interstitial nephritis was of similar intensity in both groups of infected mice. Taken together, these data suggest that LIC triggers NETs, and that the intravascular formation of these DNA traps appears to be critical not only to prevent early leptospiral dissemination but also to preclude further bacterial burden., Instituto de Biotecnologia y Biologia Molecular, Facultad de Ciencias Exactas, Facultad de Ciencias Médicas

Published
2015
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5. β-lactam antibiotics promote bacterial mutagenesis via an RpoS-mediated reduction in replication fidelity

Author

Jörg Vogel, Ivan Matic, S. Crussard, Jesús Blázquez, Luisa Laureti, Zeynep Baharoglu, Didier Mazel, F. Darfeuille, Alexandro Rodríguez-Rojas, Arnaud Gutierrez, Heni Abida, Robustesse et évolvabilité de la vie (U1001), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología [Madrid] (CNB-CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Plasticité du Génome Bactérien - Bacterial Genome Plasticity (PGB), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Régulations Naturelles et Artificielles (ARNA), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Bordeaux Ségalen [Bordeaux 2], Julius-Maximilians-Universität Würzburg (JMU), This work was supported by the FP7-HEALTH-F3-2010-241476 and ANR-09-BLAN-0251 grants. A.G. was supported by a fellowship from the French Ministry of Science and Education. D.M. was supported by the Institut Pasteur, Centre National de la Recherche Scientifique (CNRS-UMR 3525), the French National Research Agency (ANR-08-MIE-016), LABEX IBEID and the European Union Seventh Framework Programme EvoTAR. Z.B. was supported by a postdoctoral fellowship from the DIM Malinf. J.B. was supported by grants PI10/00105 (FIS) and REIPI (RD06/0008), both from Ministerio de Ciencia e Innovacion, Instituto de Salud Carlos III., We thank Dan Andersson’s lab (Uppsala University, Sweden) for providing the anti-DinB antibody, Marie Francoise Norel (Pasteur Institute, Paris) for providing the anti-RpoS antibody and Paul Modrich’s lab for providing the anti-MutS antibody., I.M., A.G., D.M., J.B., F.D. and J.V. designed the research and wrote the paper. A.G., L.L., H.A. and S.C. performed experiments with E. coli. Z.B. performed experiments and analysed data with V. cholerae. A.R.R. performed experiments and analysed data with P. aeruginosa. F.D. and J.V. performed in vitro experiments with SdsR and analysed data., ANR-09-BLAN-0251,bactadapt(2009), ANR-08-MIEN-0016,IIRE,Integrase d'integron recombinaison et expression(2008), European Project: 241476,EC:FP7:HEALTH,FP7-HEALTH-2009-single-stage,PAR(2010), European Project: 282004,EC:FP7:HEALTH,FP7-HEALTH-2011-single-stage,EVOTAR(2011), HOFFMANN, Isabelle, Blanc - - bactadapt2009 - ANR-09-BLAN-0251 - Blanc - VALID, Maladies Infectieuses et environnement - Integrase d'integron recombinaison et expression - - IIRE2008 - ANR-08-MIEN-0016 - MIE - VALID, Predicting antibiotic resistance - PAR - - EC:FP7:HEALTH2010-04-01 - 2013-03-31 - 241476 - VALID, Evolution and Transfer of Antibiotic Resistance - EVOTAR - - EC:FP7:HEALTH2011-10-01 - 2015-09-30 - 282004 - VALID, Centro Nacional de Biotecnologia, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), and Julius-Maximilians-Universität Würzburg [Wurtzbourg, Allemagne] (JMU)

Subjects
DNA Replication, medicine.drug_class, [SDV]Life Sciences [q-bio], Antibiotics, General Physics and Astronomy, Sigma Factor, MESH: DNA Replication, Biology, beta-Lactams, medicine.disease_cause, General Biochemistry, Genetics and Molecular Biology, Microbiology, 03 medical and health sciences, Antibiotic resistance, Bacterial Proteins, MESH: beta-Lactams, MESH: Anti-Bacterial Agents, Escherichia coli, medicine, Vibrio cholerae, MESH: Bacterial Proteins, 030304 developmental biology, MESH: Mutagenesis, 0303 health sciences, Multidisciplinary, Bacteria, 030306 microbiology, Pseudomonas aeruginosa, MESH: Escherichia coli, Mutagenesis, MESH: Reactive Oxygen Species, MESH: Sigma Factor, General Chemistry, biochemical phenomena, metabolism, and nutrition, Anti-Bacterial Agents, 3. Good health, [SDV] Life Sciences [q-bio], MESH: Bacteria, Regulon, MESH: Pseudomonas aeruginosa, bacteria, Reactive Oxygen Species, rpoS, MESH: Vibrio cholerae
Abstract

Antimicrobials: mismatch excels when ampicillin runs low. [Nat Rev Microbiol. 2013]; International audience; Regardless of their targets and modes of action, subinhibitory concentrations of antibiotics can have an impact on cell physiology and trigger a large variety of cellular responses in different bacterial species. Subinhibitory concentrations of β-lactam antibiotics cause reactive oxygen species production and induce PolIV-dependent mutagenesis in Escherichia coli. Here we show that subinhibitory concentrations of β-lactam antibiotics induce the RpoS regulon. RpoS regulon induction is required for PolIV-dependent mutagenesis because it diminishes the control of DNA-replication fidelity by depleting MutS in E. coli, Vibrio cholerae and Pseudomonas aeruginosa. We also show that in E. coli, the reduction in mismatch-repair activity is mediated by SdsR, the RpoS-controlled small RNA. In summary, we show that mutagenesis induced by subinhibitory concentrations of antibiotics is a genetically controlled process. Because this mutagenesis can generate mutations conferring antibiotic resistance, it should be taken into consideration for the development of more efficient antimicrobial therapeutic strategies.

Published
2013
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6. Synchrotron FTIR microspectroscopy of Escherichia coli at single-cell scale under silver-induced stress conditions

Author

Claire Saulou, Muriel Mercier-Bonin, Isabelle Fourquaux, Paul Dumas, Claude Maranges, Frédéric Jamme, Muriel Cocaign-Bousquet, Laurence Girbal, Génie et Microbiologie des Procédés Alimentaires (GMPA), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP), Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT), Centre de Microscopie Électronique Appliquée à la Biologie (CMEAB), Toulouse Réseau Imagerie-Genotoul ( TRI-Genotoul), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), The authors gratefully acknowledge the 'BioPleasure' project of the Research National Agency (ANR-07-BLAN-0196-01) for funding., The research described in this paper was performed at the French national synchrotron facility SOLEIL (Gif-sur- Yvette, France), using the SMIS beamline (proposal no 20090556)., ANR-07-BLAN-0196,BIOPLEASURE,Plasma - surface engineering for biofilm prevention(2007), AgroParisTech-Institut National de la Recherche Agronomique (INRA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées, Institut National des Sciences Appliquées (INSA), Hôpital de Rangueil, CHU Toulouse [Toulouse]-CHU Toulouse [Toulouse]-Toulouse Réseau Imagerie-Genotoul ( TRI-Genotoul), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Recherche Agronomique (INRA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Hôpital de Rangueil, and CHU Toulouse [Toulouse]-CHU Toulouse [Toulouse]

Subjects
In situ, Analytical chemistry, medicine.disease_cause, Biochemistry, Analytical Chemistry, 03 medical and health sciences, Stress, Physiological, Spectroscopy, Fourier Transform Infrared, medicine, Escherichia coli, Fourier transform infrared spectroscopy, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Protein secondary structure, 030304 developmental biology, 0303 health sciences, biology, Ionic silver, 030306 microbiology, Chemistry, Synchrotron FTIR-ATR microspectroscopy, Single-cell scale, [CHIM.MATE]Chemical Sciences/Material chemistry, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Antibacterial effect, Transmission electron microscopy, Attenuated total reflection, Ultrastructure, Biophysics, Silver Nitrate, Single-Cell Analysis, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Synchrotrons, Bacteria
Abstract

International audience; The present work was focused on elucidating biochemical changes in the model bacterium Escherichia coli exposed to ionic silver mediated stress, at a single-cell scale. In order to achieve this, in situ synchrotron Fourier-transform infrared (sFTIR) microspectroscopy was performed, for the first time, on individual cells by attenuated total reflectance (ATR) combined with the use of zinc-selenide hemisphere for high spatial resolution. In a first part, the potential of the method was evaluated on bacteria subjected to a lethal 100 μM AgNO3 concentration for 2 h compared to untreated 100 % viable cells. Differences in cell composition were assessed for the C–H stretching and protein spectral regions, indicating that the inhibitory action was targeted against both fatty acids and proteins. Transmission electron microscopy (TEM) confirmed morphological damages of the cell ultrastructure. The relevance of ATR-sFTIR microspectroscopy for highlighting the heterogeneity in Ag+-mediated effects within a given bacterial population was also pointed out. In a second part, cells were exposed to sub-lethal Ag+ concentrations (

Published
2013
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7. RNA sequencing revealed novel actors of the acquisition of drug resistance in Candida albicans

Author

Jean-Yves Coppée, Gaëlle Lelandais, Odile Sismeiro, Sophie Lemoine, Frédéric Devaux, Stéphane Le Crom, Rajendra Prasad, Maria Bernard, Sanjiveeni Dhamgaye, Membrane Biology Laboratory, Jawaharlal Nehru University (JNU), Institut de biologie de l'ENS Paris (UMR 8197/1024) (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Dynamique des Structures et Interactions des Macromolécules Biologiques - Pôle de La Réunion (DSIMB Réunion), Biologie Intégrée du Globule Rouge (BIGR (UMR_S_1134 / U1134)), Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université des Antilles (UA)-Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université des Antilles (UA), Transcriptome et Epigénome (PF2), Institut Pasteur [Paris], Génomique des Microorganismes (LGM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), The work presented in this paper has been supported in part by grants to R.P. from Indo-French Center for the Promotion of Advanced Scientific Research (IFC-3403-2/2006) and DST INT/SWISS/P-31/2009., Institut de biologie de l'ENS Paris (IBENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Institut Pasteur [Paris] (IP), BMC, Ed., Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Biologie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Université des Antilles (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Université des Antilles (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Candida albicans, beta-Glucans, lcsh:QH426-470, lcsh:Biotechnology, Repressor, RNA-Seq, Drug resistance, Multidrug resistance, Fungal Proteins, 03 medical and health sciences, Drug Resistance, Fungal, lcsh:TP248.13-248.65, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Transcriptional regulation, Genetics, CZF1, Gene, 030304 developmental biology, 0303 health sciences, biology, 030306 microbiology, Sequence Analysis, RNA, Gene Expression Profiling, biology.organism_classification, Yeast, 3. Good health, Multiple drug resistance, Gene expression profiling, lcsh:Genetics, [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], RNA-seq, Biotechnology, Transcription Factors, Research Article
Abstract

Background Drug susceptible clinical isolates of Candida albicans frequently become highly tolerant to drugs during chemotherapy, with dreadful consequences to patient health. We used RNA sequencing (RNA-seq) to analyze the transcriptomes of a CDR (Candida Drug Resistance) strain and its isogenic drug sensitive counterpart. Results RNA-seq unveiled differential expression of 228 genes including a) genes previously identified as involved in CDR, b) genes not previously associated to the CDR phenotype, and c) novel transcripts whose function as a gene is uncharacterized. In particular, we show for the first time that CDR acquisition is correlated with an overexpression of the transcription factor encoding gene CZF1. CZF1 null mutants were susceptible to many drugs, independently of known multidrug resistance mechanisms. We show that CZF1 acts as a repressor of β-glucan synthesis, thus negatively regulating cell wall integrity. Finally, our RNA-seq data allowed us to identify a new transcribed region, upstream of the TAC1 gene, which encodes the major CDR transcriptional regulator. Conclusion Our results open new perspectives of the role of Czf1 and of our understanding of the transcriptional and post-transcriptional mechanisms that lead to the acquisition of drug resistance in C. albicans, with potential for future improvements of therapeutic strategies.

Published
2012
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8. An rpoB signature sequence provides unique resolution for the molecular typing of cyanobacteria

Author

Simonetta Gribaldo, Virginie Gaget, Nicole Tandeau de Marsac, Collection des Cyanobactéries, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Biologie Moléculaire du Gène chez les Extrêmophiles (BMGE), Institut Pasteur [Paris], We wish to thank the CAE (Centre d'Analyses Environnementales) of Veolia Environment, the Institut Pasteur and CNRS URA-2172 for funding this work. We are grateful to the CAE of Veolia Environment for providing a thesis fellowship to V. G., and to K. Delabre and F. Enguehard for constant support during this study. We express our gratitude to T. Rose for his advice on three-dimensional predictions and thank J. P. Rasmussen for helpful comments and his revision of the English during the preparation of this paper., Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris] (IP)

Subjects
DNA, Bacterial, NJ, [SDV]Life Sciences [q-bio], Biology, Cyanobacteria, Microbiology, MESH: Bacterial Typing Techniques, MESH: INDEL Mutation, 03 medical and health sciences, chemistry.chemical_compound, Bacterial Proteins, INDEL Mutation, maximum-parsimony, RNA polymerase, Indel, Gene, MESH: Bacterial Proteins, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, Genetics, 0303 health sciences, MESH: Molecular Typing, 030306 microbiology, MP, DNA-Directed RNA Polymerases, General Medicine, MESH: Cyanobacteria, rpoB, 16S ribosomal RNA, ML, neighbour-joining, MESH: DNA, Bacterial, Bacterial Typing Techniques, MESH: DNA-Directed RNA Polymerases, Molecular Typing, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, chemistry, Evolutionary biology, Metagenomics, maximum-likelihood, Subgenus, DNA
Abstract

The use of morphological characters for the classification of cyanobacteria has often led to ambiguous strain assignment. In the past two decades, the availability of sequences, such as those of the 16S rRNA,nif,cpcandrpoC1genes, and the use of metagenomics, has steadily increased and has made the reconstruction of evolutionary relationships of some cyanobacterial groups possible in addition to improving strain assignment. Conserved indels (insertions/deletions) are present in all cyanobacterial RpoB (βsubunit of RNA polymerase) sequences presently available in public databases. These indels are located in the Rpb2_6 domain of RpoB, which is involved in DNA binding and DNA-directed RNA polymerase activity. They are variable in length (6–44 aa) and sequence, and form part of what appears to be a longer signature sequence (43–81 aa). Indeed, a number of these sequences turn out to be distinctive among several strains of a given genus and even among strains of a given species. These signature sequences can thus be used to identify cyanobacteria at a subgenus level and can be useful molecular markers to establish the taxonomic positions of cyanobacterial isolates in laboratory cultures, and/or to assess cyanobacterial biodiversity in space and time in natural ecosystems.

Published
2011
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9. Mus spretus SEG/Pas mice resist virulent Yersinia pestis, under multigenic control

Author

C. Fayolle, Elisabeth Carniel, Marek Szatanik, Geneviève Milon, Charlène Blanchet, Jean-Jacques Panthier, Xavier Montagutelli, Jean Jaubert, Génétique Fonctionnelle de la Souris, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Yersinia, Institut Pasteur [Paris] (IP), Immunophysiologie et Parasitisme Intracellulaire, CB is a recipient of a DGA (Délégation Générale pour l’Armement) fellowship. This work was supported by a grant from Aventis Pharma (Sanofi-Aventis group) and Bayer Pharma as part of a multi-organism call for proposal. The Mouse functional Genetics Unit is supported by Merck Serono., We thank Jean-Louis Guénet for his constant interest and challenging discussions. We are grateful to Colin Crist for critical reading and suggestions on the paper, to Isabelle Lanctin for careful breeding of the SEG/Pas colony, and to the CNG (Centre National de Génotypage) for the SNP genotyping of BC mice., Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris]

Subjects
Male, Yersinia pestis, Mus spretus, Quantitative Trait Loci, Immunology, MESH: Yersinia pestis, Virulence, Quantitative trait locus, Mice, 03 medical and health sciences, Species Specificity, Genetics, Animals, MESH: Species Specificity, MESH: Animals, Allele, MESH: Mice, Genetics (clinical), 030304 developmental biology, 0303 health sciences, [SDV.GEN]Life Sciences [q-bio]/Genetics, biology, 030306 microbiology, Wild type, biology.organism_classification, Phenotype, Immunity, Innate, MESH: Male, MESH: Quantitative Trait Loci, 3. Good health, Backcrossing, Female, MESH: Immunity, Innate, MESH: Female
Abstract

International audience; Laboratory mice are well known to be highly susceptible to virulent strains of Yersinia pestis in experimental models of bubonic plague. We have found that Mus spretus-derived SEG/Pas (SEG) mice are exceptionally resistant to virulent CO92 and 6/69 wild type strains. Upon subcutaneous injection of 10(2) colony-forming units (CFU), 90% of females and 68% of males survived, compared with only an 8% survival rate for both male and female C57BL/6 mice. Furthermore, half of the SEG mice survived a challenge of up to 10(7) CFU. The time required for mortality was similar between B6 and SEG, suggesting that survival is dependent on early rather than late processes. The analysis of 322 backcross mice identified three significant quantitative trait loci (QTLs) on chromosomes 3, 4 and 6, with dominant SEG protective alleles. Each QTL increased the survival rate by approximately 20%. The three QTLs function additively, thereby accounting for 67% of the difference between the parental phenotypes. Mice heterozygous for the three QTLs were just as resistant as SEG mice to Y. pestis challenge. The SEG strain therefore offers an invaluable opportunity to unravel mechanisms and underlying genetic factors of resistance against Y. pestis infection.

Published
2011
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10. Malaria risk in Corsica, former hot spot of malaria in France

Author

Gilbert Le Goff, Céline Toty, Hélène Barré, Daniel Couret, Nil Rahola, Didier Fontenille, Isabelle Larget-Thiery, Caractérisation et contrôle des populations de vecteurs, Institut de Recherche pour le Développement (IRD), Direction de la Solidarité et de la Santé de Corse et de Corse-du-Sud, Sciences pour l'environnement (SPE), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), Centre de Production et Infection des Anophèles (plateforme) - Center for the Production and Infection of Anopheles (platform) (CEPIA), Institut Pasteur [Paris], The paper is catalogued by the EDEN Steering Committee as EDEN 232 http://www.eden-fp6project.net/., Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), Institut Pasteur [Paris] (IP), and Centre de Production et Infection des Anophèles (Plateforme) (CEPIA)

Subjects
Risk, Entomology, lcsh:Arctic medicine. Tropical medicine, lcsh:RC955-962, 030231 tropical medicine, Plasmodium vivax, Plasmodium falciparum, MESH: Malaria, Zoology, MESH: Insect Vectors, Biology, Plasmodium, Polymerase Chain Reaction, lcsh:Infectious and parasitic diseases, MESH: Anopheles, 03 medical and health sciences, 0302 clinical medicine, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Anopheles, parasitic diseases, medicine, Animals, Humans, MESH: Animals, lcsh:RC109-216, MESH: Plasmodium falciparum, 0303 health sciences, MESH: Humans, MESH: Risk, 030306 microbiology, Ecology, Research, Outbreak, MESH: Polymerase Chain Reaction, medicine.disease, biology.organism_classification, 3. Good health, Insect Vectors, Malaria, MESH: Plasmodium vivax, MESH: France, Infectious Diseases, Parasitology, France
Abstract

Background The prevalence of Plasmodium falciparum and Plasmodium vivax malaria was very high in Corsica just before the Second World War. The last outbreak was in 1972 and the most recent indigenous case was in 2006. Results Analysis of historical data shows that anopheline vectors were abundant. Recent surveys demonstrated that potential vectors are still present in Corsica, despite the likely disappearance of Anopheles sacharovi. Moreover, P. falciparum can develop experimentally into these mosquitoes, notably Anopheles labranchiae, which is locally abundant, and parasites are regularly introduced into the island. Discussion, Conclusions The presence of vectors, the introduction of parasites and the conducive climate raise questions about the possibility of malaria re-emerging and becoming re-established in Corsica. Analysis of historic and current parasitological and entomological data shows that the current theoretical risk of indigenous cases or malaria foci is negligible, particularly since there is very little contact between humans and Anopheles mosquitoes, Plasmodium carriers are reliably treated and there is a widespread vector control on the island.

Published
2010
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11. Characterization of Staphylococcus aureus strains associated with food poisoning outbreaks in France

Author

Jacques-Antoine Hennekinne, Annaëlle Kerouanton, L. Petit, C. Letertre, Anne Brisabois, O. Chesneau, M.L. De Buyser, Agence Française de Sécurité Sanitaire des Aliments (AFSSA), Agents antibactériens, Institut Pasteur [Paris], We acknowledge the technical assistance of Trinh Tam Dao, Marie-Odile Delbart, Muriel Marault, and Anne Morvan. We dedicate this paper to the memory of Névine El Solh who contributed to the phage-typing and who passed away in January 2005., and Institut Pasteur [Paris] (IP)

Subjects
Salmonella, Enterotoxin, MESH: Base Sequence, medicine.disease_cause, SmaI, Disease Outbreaks, MESH: Genotype, Enterotoxins, Genotype, MESH: Staphylococcus aureus, MESH: Enterotoxins, Cluster Analysis, MESH: Disease Outbreaks, MESH: Phylogeny, Phylogeny, 2. Zero hunger, 0303 health sciences, General Medicine, PFGE, 3. Good health, Electrophoresis, Gel, Pulsed-Field, Phenotype, MESH: Electrophoresis, Gel, Pulsed-Field, Staphylococcus aureus, MESH: Staphylococcal Food Poisoning, France, Staphylococcal Food Poisoning, Food Contamination, Biology, MESH: Phenotype, Microbiology, Food-poisoning, 03 medical and health sciences, medicine, Pulsed-field gel electrophoresis, Humans, MESH: Food Microbiology, 030304 developmental biology, MESH: Humans, Base Sequence, 030306 microbiology, Outbreak, MESH: Food Contamination, MESH: Cluster Analysis, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, MESH: France, Food Microbiology, Food Science
Abstract

International audience; Enterotoxins produced by Staphylococcus aureus are responsible for staphylococcal food-poisoning outbreaks (SFPO). In France, SFPO are the second cause of food-borne diseases after Salmonella. However, very little is known about the strains involved. The objective of this study was to characterize the staphylococcal strains related to these SFPO through phenotypic and genotypic analyses. A total of 178 coagulase-positive staphylococcal isolates recovered from 31 SFPO (1981-2002) were screened through biotyping. Thirty-three strains representative of the different biotypes in each SFPO were further examined for SmaI macrorestriction-type, phage-type, resistance to various antimicrobial drugs, presence of staphylococcal enterotoxin (se) genes sea to sei, and production of enterotoxins SEA to SED. All these 33 strains were identified as S. aureus species: 27 were of human biotypes and six ovine or non-host-specific biotypes. Most (74.1%) strains reacted with group III phages. Eleven strains were resistant to at least two classes of antibiotics and among them, two were resistant to methicillin. Twenty-nine strains carried one or several of the eight se genes tested; the gene sea was most common (n=23), and often linked to sed (n=12) or seh (n=5). The novel se genes seg-i were in all cases associated with se genes sea to sed except for one strain which carried only seg and sei. Pulsed-Field Gel Electrophoresis (PFGE) of SmaI macrorestriction digests of the 33 strains discriminated 32 PFGE patterns grouped into nine biotype-specific clusters. All five strains carrying sea and seh were grouped together into the same sub-cluster. Three of the four se-gene-negative strains were in one PFGE cluster: all four should be tested for se genes not included in this study and, if negative, be further investigated for the presence of unidentified SEs.

Published
2007
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12. Shigella flexneri 2a strain 2457T expresses three members of the H-NS-like protein family: characterization of the Sfh protein

Author

Christophe Beloin, Padraig Deighan, Charles J. Dorman, Marie Doyle, Génétique des Biofilms, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), University of Dublin, This work was supported by European Training and Mobility of Researchers Award ERBFMRXCT98-0164, Wellcome Trust Award 064284/Z01/Z and Enterprise Ireland Award SC/2002/22. P. Deighan was supported by a Wellcome Trust Prize Fellowship. The research described in this paper was performed in compliance with current laws governing genetic experimentation in the Republic of Ireland, We thank Philippe Bertin for the E. coli strains BE1414 and YK3421, Maria Mavris for S. flexneri strains, and Pablo Garcia Bravo and Antonio Cerqueira for help with protein purification., and Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS)

Subjects
MESH: Operon, MESH: Shigella flexneri, Protein family, [SDV]Life Sciences [q-bio], Virulence, Plasmid R27, Shigella flexneri, H-NS protein, 03 medical and health sciences, Plasmid, Bacterial Proteins, MESH: Plasmids, Operon, Genetics, Escherichia coli, MESH: Phylogeny, MESH: Bacterial Proteins, Molecular Biology, Gene, Phylogeny, 030304 developmental biology, Regulator gene, Regulation of gene expression, MESH: Gene Expression Regulation, Bacterial, 0303 health sciences, biology, MESH: Escherichia coli, 030306 microbiology, Structural gene, Sfh protein, General Medicine, Gene Expression Regulation, Bacterial, biology.organism_classification, Molecular biology, DNA-Binding Proteins, StpA protein, MESH: DNA-Binding Proteins, Plasmids
Abstract

Shigella flexneri 2a is known to express the H-NS nucleoid-structuring protein and the paralogous protein StpA. Using bioinformatic analysis we have now discovered a third member of the H-NS protein family, Sfh (S higella f lexneri H-NS-like protein), in strain 2457T. This protein is encoded by the sfh gene, which is located on a high-molecular-mass plasmid that is closely related to the self-transmissible plasmid R27. When expressed in Escherichia coli, the Sfh protein can complement an hns null mutation, restoring wild-type Bgl, porin protein, and mucoidy phenotypes, and wild-type expression of the fliC and proU genes. While a knockout mutation in the sfh gene alone had no effect on the expression of virulence genes in S. flexneri, an additive effect on virulence gene derepression was seen when the sfh lesion was combined with a mutation in hns. Over-expression of the sfh gene repressed expression of the VirB virulence regulatory protein and transcription of a VirB-dependent structural gene promoter. The purified Sfh protein bound specifically to DNA sequences containing the promoters of the virF and virB virulence regulatory genes. These findings show that Sfh has the ability to influence genetic events beyond the genetic element that encodes it, including the expression of the S. flexneri virulence genes. They raise the possibility of a triangular relationship among three closely related proteins with broad consequences for genetic events in the bacterium that harbours them.

Published
2003
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