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| Registros recuperados: 25 | |
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| Schmitt, Paulina; Wilmes, Miriam; Pugniere, Martine; Aumelas, Andre; Bachere, Evelyne; Sahl, Hans-georg; Schneider, Tanja; Destoumieux-garzon, Delphine. |
| Three oyster defensin variants (Cg-Defh1, Cg-Defh2, and Cg-Defm) were produced as recombinant peptides and characterized in terms of activities and mechanism of action. In agreement with their spectrum of activity almost specifically directed against Gram-positive bacteria, oyster defensins were shown here to be specific inhibitors of a bacterial biosynthesis pathway rather than mere membrane-active agents. Indeed, at lethal concentrations, the three defensins did not compromise Staphylococcus aureus membrane integrity but inhibited the cell wall biosynthesis as indicated by the accumulation of the UDP-N-acetylmuramyl-pentapeptide cell wall precursor. In addition, a combination of antagonization assays, thin layer chromatography, and surface plasmon... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12503/9369.pdf |
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| Vassiliadis, Gaelle; Destoumieux-garzon, Delphine; Peduzzi, Jean. |
| Class II microcins are 4.9- to 8.9-kDa polypeptides produced by and active against enterobacteria. They are classified into two subfamilies according to their structure and their gene cluster arrangement. While class ha microcins undergo no posttranslational modification, class Jib rnicrocins show a conserved C-terminal sequence that carries a salmochelin-like siderophore motif as a posttranslational modification. Aside from this C-terminal end, which is the signature of class IIb microcins, some sequence similarities can be observed within and between class II subclasses, suggesting the existence of common ancestors. Their mechanisms of action are still under investigation, but several class II microcins use inner membrane proteins as cellular targets,... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00073/18386/16447.pdf |
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| Vidal-dupiol, Jeremie; Ladriere, Ophelie; Destoumieux-garzon, Delphine; Sautiere, Pierre-eric; Meistertzheim, Anne-leila; Tambutte, Eric; Tambutte, Sylvie; Duval, David; Foure, Laurent; Adjeroud, Mehdi; Mitta, Guillaume. |
| Scleractinian corals are the most basal eumetazoan taxon and provide the biological and physical framework for coral reefs, which are among the most diverse of all ecosystems. Over the past three decades and coincident with climate change, these phototrophic symbiotic organisms have been subject to increasingly frequent and severe diseases, which are now geographically widespread and a major threat to these ecosystems. Although coral immunity has been the subject of increasing study, the available information remains fragmentary, especially with respect to coral antimicrobial responses. In this study, we characterized damicornin from Pocillopora damicornis, the first scleractinian antimicrobial peptide (AMP) to be reported. We found that its precursor has... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00039/14996/12433.pdf |
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| Duperthuy, Marylise; Schmitt, Paulina; Garzon, Edwin; Caro, Audrey; Rosa, Rafael D.; Le Roux, Frederique; Lautredou-audouy, Nicole; Got, Patrice; Romestand, Bernard; De Lorgeril, Julien; Kieffer-jaquinod, Sylvie; Bachere, Evelyne; Destoumieux-garzon, Delphine. |
| OmpU porins are increasingly recognized as key determinants of pathogenic host Vibrio interactions. Although mechanisms remain incompletely understood, various species, including the human pathogen Vibrio cholera, require OmpU for host colonization and virulence. We have shown previously that OmpU is essential for virulence in the oyster pathogen Vibrio splendidus LGP32. Here, we showed that V. splendidus LGP32 invades the oyster immune cells, the hemocytes, through subversion of host-cell actin cytoskeleton. In this process, OmpU serves as an adhesin/invasin required for beta-integrin recognition and host cell invasion. Furthermore, the major protein of oyster plasma, the extracellular superoxide dismutase Cg-EcSOD, is used as an opsonin mediating the... |
| Tipo: Text |
Palavras-chave: Host-pathogen interaction; Innate immunity; Invertebrate; Mollusk; Oxidative burst. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14177/12166.pdf |
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| Rosa, Rafael D.; Santini, Adrien; Fievet, Julie; Bulet, Philippe; Destoumieux-garzon, Delphine; Bachere, Evelyne. |
| Background: Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. Findings: Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3) that are... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00050/16096/13576.pdf |
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| Duvic, B.; Jouan, V.; Essa, N.; Girard, P-a; Pages, S.; Khattar, Z. Abi; Volkoff, N-a; Givaudan, A.; Destoumieux-garzon, Delphine; Escoubas, Jean-michel. |
| An antimicrobial peptide (AMP) of the cecropin family was isolated by HPLC from plasma of the insect pest, Spodoptera frugiperda. Its molecular mass is 3910.9 Da as determined by mass spectrometry. Thanks to the EST database Spodobase, we were able to describe 13 cDNAs encoding six different cecropins which belong to the sub-families CecA, CecB, CecC and CecD. The purified peptide identified as CecB1 was chemically synthesized (syCecB1). It was shown to be active against Gram-positive and Gram-negative bacteria as well as fungi. Two closely related entomopathogenic bacteria, Xenorhabdus nematophila F1 and Xenorhabdus mauleonii VC01(T) showed different susceptibility to syCecB1. Indeed, X. nematophila was sensitive to syCecB1 whereas X. mauleonii had a... |
| Tipo: Text |
Palavras-chave: Humoral immunity; Innate immunity; Immunosuppression; Lepidopteran; Invertebrate. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19728/17485.pdf |
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| Rosa, Rafael Diego; Vergnes, Agnes; De Lorgeril, Julien; Goncalves, Priscila; Perazzolo, Luciane Maria; Saune, Laure; Romestand, Bernard; Fievet, Julie; Gueguen, Yannick; Bachere, Evelyne; Destoumieux-garzon, Delphine. |
| Antilipopolysaccharide factors (ALFs) have been described as highly cationic polypeptides with a broad spectrum of potent antimicrobial activities. In addition, ALFs have been shown to recognize LPS, a major component of the Gram-negative bacteria cell wall, through conserved amino acid residues exposed in the four-stranded beta-sheet of their three dimensional structure. In penaeid shrimp, ALFs form a diverse family of antimicrobial peptides composed by three main variants, classified as ALF Groups A to C. Here, we identified a novel group of ALFs in shrimp (Group D ALFs), which corresponds to anionic polypeptides in which many residues of the LPS binding site are lacking. Both Group B (cationic) and Group D (anionic) shrimp ALFs were produced in a... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00160/27077/25236.pdf |
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| Poirier, Aurore C.; Schmitt, Paulina; Rosa, Rafael D.; Vanhove, Audrey S.; Kieffer-jaquinod, Sylvie; Rubio, Tristan P.; Charriere, Guillaume M.; Destoumieux-garzon, Delphine. |
| Although antimicrobial histones have been isolated from multiple metazoan species, their role in host defense has long remained unanswered. We found here that the hemocytes of the oyster Crassostrea gigas release antimicrobial H1-like and H5-like histones in response to tissue damage and infection. These antimicrobial histones were shown to be associated with extracellular DNA networks released by hemocytes, the circulating immune cells of invertebrates, in response to immune challenge. The hemocyte-released DNA was found to surround and entangle vibrios. This defense mechanism is reminiscent of the neutrophil extracellular traps (ETs) recently described in vertebrates. Importantly, oyster ETs were evidenced in vivo in hemocyte-infiltrated interstitial... |
| Tipo: Text |
Palavras-chave: Antimicrobial Peptide (AMP); DNA; Innate Immunity; Invertebrate; Reactive Oxygen Species (ROS); NET; Mollusk. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00217/32866/31784.pdf |
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| Bachere, Evelyne; Rosa, Rafael Diego; Schmitt, Paulina; Poirier, Aurore; Merou, Nicolas; Charriere, Guillaume; Destoumieux-garzon, Delphine. |
| Oysters are sessile filter feeders that live in close association with abundant and diverse communities of microorganisms that form the oyster microbiota. In such an association, cellular and molecular mechanisms have evolved to maintain oyster homeostasis upon stressful conditions including infection and changing environments. We give here cellular and molecular insights into the Crassostrea gigas antimicrobial defense system with focus on antimicrobial peptides and proteins (AMPs). This review highlights the central role of the hemocytes in the modulation and control of oyster antimicrobial response. As vehicles for AMPs and other antimicrobial effectors, including reactive oxygen species (ROS), and together with epithelia, hemocytes provide the oyster... |
| Tipo: Text |
Palavras-chave: Mollusk; Immunity; Antimicrobial peptide; Hemocyte; Defensin. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36552/35097.pdf |
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| Le Roux, Frederique; Wegner, K. Mathias; Baker-austin, Craig; Vezzulli, Luigi; Osorio, Carlos R.; Amaro, Carmen; Ritchie, Jennifer M.; Defoirdt, Tom; Destoumieux-garzon, Delphine; Blokesch, Melanie; Mazel, Didier; Jacq, Annick; Cava, Felipe; Gram, Lone; Wendling, Carolin C.; Strauch, Eckhard; Kirschner, Alexander; Huehn, Stephan. |
| Global change has caused a worldwide increase in reports of Vibrio-associated diseases with ecosystem-wide impacts on humans and marine animals. In Europe, higher prevalence of human infections followed regional climatic trends with outbreaks occurring during episodes of unusually warm weather. Similar patterns were also observed in Vibrio-associated diseases affecting marine organisms such as fish, bivalves and corals. Basic knowledge is still lacking on the ecology and evolutionary biology of these bacteria as well as on their virulence mechanisms. Current limitations in experimental systems to study infection and the lack of diagnostic tools still prevent a better understanding of Vibrio emergence. A major challenge is to foster cooperation between... |
| Tipo: Text |
Palavras-chave: Global warming; Human health; Aquaculture; Interactions; Animal model; Bacterial disease; Genome plasticity; European network. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00278/38952/37494.pdf |
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| Vanhove, Audrey; Duperthuy, Marylise; Charriere, Guillaume; Le Roux, Frederique; Goudenege, David; Gourbal, Benjamin; Kieffer-jaquinod, Sylvie; Coute, Yohann; Wai, Sun Nyunt; Destoumieux-garzon, Delphine. |
| Vibrio tasmaniensis LGP32, a facultative intracellular pathogen of oyster haemocytes, was shown here to release outer membrane vesicles (OMVs) both in the extracellular milieu and inside haemocytes. Intracellular release of OMVs occurred inside phagosomes of intact haemocytes having phagocytosed few vibrios as well as in damaged haemocytes containing large vacuoles heavily loaded with LGP32. The OMV proteome of LGP32 was shown to be rich in hydrolases (25%) including potential virulence factors such as proteases, lipases, phospholipases, haemolysins and nucleases. One major caseinase/gelatinase named Vsp for vesicular serine protease was found to be specifically secreted through OMVs in which it is enclosed. Vsp was shown to participate in the virulence... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00199/31009/29459.pdf |
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| Petit, Vanessa W.; Rolland, Jean-luc; Blond, Alain; Cazevieille, Chantal; Djediat, Chakib; Peduzzi, Jean; Goulard, Christophe; Bachere, Evelyne; Dupont, Joelle; Destoumieux-garzon, Delphine; Rebuffat, Sylvie. |
| Background. Hemocyanins are respiratory proteins with multiple functions. In diverse crustaceans hemocyanins can release histidine-rich antimicrobial peptides in response to microbial challenge. In penaeid shrimp, strictly antifungal peptides are released from the C-terminus of hemocyanins. Methods. The three-dimensional structure of the antifungal peptide PvHCt from Litopenaeus vannamei was determined by NMR. Its mechanism of action against the shrimp pathogen Fusarium oxysporum was investigated using immunochemistry, fluorescence and transmission electron microscopy. Results. PvHCt folded into an amphipathic α-helix in membrane-mimicking media and displayed a random conformation in aqueous environment. In contact with F. oxysporum, PvHCt bound... |
| Tipo: Text |
Palavras-chave: Antimicrobial peptide; Amphipathic helix; Fungi; Membrane bilayer; Nuclear magnetic resonance (NMR); Fluorescence microscopy. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00301/41202/40362.pdf |
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| Abikhalil, Celina; Finkelstein, Darren S.; Conejero, Genevieve; Du Bois, Justin; Destoumieux-garzon, Delphine; Rolland, Jean-luc. |
| Exposure of the toxin-producing dinoflagellate Alexandrium catenella (A. catenella) was previously demonstrated to cause apoptosis of hemocytes in the oyster species Crassostrea gigas. In this work, a coumarin-labeled saxitoxin appeared to spread throughout the cytoplasm of the hemocytes. PSTs, including saxitoxin, were also shown to be directly responsible for inducing apoptosis in hemocytes, a process dependent on caspase activation and independent of reactive oxygen species (ROS) production. A series of in vitro labeling and microscopy experiments revealed that STX and analogs there of induced nuclear condensation, phosphatidylserine exposure, membrane permeability, and DNA fragmentation of hemocytes. Unlike in vertebrates, gonyautoxin-5 (GTX5), which... |
| Tipo: Text |
Palavras-chave: Shellfish; Toxin; Harmful algae; Phytoplankton. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00391/50272/50905.pdf |
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| De Lorgeril, Julien; Lucasson, Aude; Petton, Bruno; Toulza, Eve; Montagnani, Caroline; Clerissi, Camille; Vidal-dupiol, Jeremie; Chaparro, Cristian; Galinier, Richard; Escoubas, Jean Michel; Haffner, Philippe; Degremont, Lionel; Charriere, Guillaume; Lafont, Maxime; Delort, Abigail; Vergnes, Agnes; Chiarello, Marlene; Faury, Nicole; Rubio, Tristan; Leroy, Marc; Perignon, Adeline; Regler, Denis; Morga, Benjamin; Alunno-bruscia, Marianne; Boudry, Pierre; Le Roux, Frederique; Destoumieux-garzon, Delphine; Gueguen, Yannick; Mitta, Guillaume. |
| Infectious diseases are mostly explored using reductionist approaches despite repeated evidence showing them to be strongly in fluenced by numerous interacting host and environmental factors. Many diseases with a complex aetiology therefore remain misunderstood. By developing a holistic approach to tackle the complexity of interactions, we decipher the complex intra-host interactions underlying Pacific oyster mortality syndrome affecting juveniles of Crassostrea gigas, the main oyster species exploited worldwide. Using experimental infections reproducing the natural route of infection and combining thorough molecular analyses of oyster families with contrasted susceptibilities, we demonstrate that the disease is caused by multiple infection with an initial... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57234/59228.pdf |
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| Lopez-joven, Maria-carmen; Rolland, Jean-luc; Haffner, Philippe; Caro, Audrey; Roques, Cecile; Carre, Claire; Travers, Marie-agnes; Abadie, Eric; Laabir, Mohamed; Bonnet, Delphine; Destoumieux-garzon, Delphine. |
| Vibrio species have been associated with recurrent mass mortalities of juvenile oysters Crassostrea gigas threatening oyster farming worldwide. However, knowledge of the ecology of pathogens in affected oyster farming areas remains scarce. Specifically, there are no data regarding (i) the environmental reservoirs of Vibrio populations pathogenic to oysters, (ii) the environmental factors favoring their transmission, and (iii) the influence of oyster farming on the persistence of those pathogens. This knowledge gap limits our capacity to predict and mitigate disease occurrence. To address these issues, we monitored Vibrio species potentially pathogenic to C. gigas in 2013 and 2014 in the Thau Lagoon, a major oyster farming region in the coastal French... |
| Tipo: Text |
Palavras-chave: Vibrio; Shellfish farming; Bivalve mollusks; Mortality outbreak; Phytoplankton; Zooplankton. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57479/59598.pdf |
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| Nguyen, An Ngoc; Disconzi, Elena; Charriere, Guillaume; Destoumieux-garzon, Delphine; Bouloc, Philippe; Le Roux, Frederique; Jacq, Annick. |
| CsrBs are bacterial highly conserved and multiple-copy noncoding small RNAs (sRNAs) that play major roles in cell physiology and virulence. In the Vibrio genus, they are known to be regulated by the two-component system VarSNarA. They modulate the well-characterized quorum sensing pathway controlling virulence and luminescence in Vibrio cholerae and Vibrio harveyi, respectively. Remarkably, Vibrio tasmaniensis LGP32, an oyster pathogen that belongs to the Splendidus Glade, was found to have four copies of csrB, named csrB1-4, compared to two to three copies in other Vibrio species. Here, we show that the extra csrB4 copy results from a csrB3 gene duplication, a characteristic of the Splendidus Glade. Interestingly, csrB genes are regulated in different... |
| Tipo: Text |
Palavras-chave: Bacterial gene regulation; Bacterial sRNAs; Transcriptomics; Vibrio pathogenic to oysters; Host-pathogen interactions. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00476/58785/61319.pdf |
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| Destoumieux-garzon, Delphine; Mavingui, Patrick; Boetsch, Gilles; Boissier, Jerome; Darriet, Frederic; Duboz, Priscilla; Fritsch, Clementine; Giraudoux, Patrick; Le Roux, Frederique; Morand, Serge; Paillard, Christine; Pontier, Dominique; Sueur, Cedric; Voituron, Yann. |
| Over the past decade, a significant increase in the circulation of infectious agents was observed. With the spread and emergence of epizootics, zoonoses, and epidemics, the risks of pandemics became more and more critical. Human and animal health has also been threatened by antimicrobial resistance, environmental pollution, and the development of multifactorial and chronic diseases. This highlighted the increasing globalization of health risks and the importance of the human–animal–ecosystem interface in the evolution and emergence of pathogens. A better knowledge of causes and consequences of certain human activities, lifestyles, and behaviors in ecosystems is crucial for a rigorous interpretation of disease dynamics and to drive public policies. As a... |
| Tipo: Text |
Palavras-chave: One health; EcoHealth; Infectious disease; Non-communicable disease; Multifactorial disease; Ecotoxicology; Interdisciplinary research; Public health. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00425/53676/54518.pdf |
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| Registros recuperados: 25 | |
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