Christine Paillard

French National Centre for Scientific Research | CNRS · Institut universitaire européen de la mer (IUEM)

Résumé / Abstract Des spécimens de palourdes européennes Ruditapes decussatus provenant des fouilles de l’amas coquillier mésolithique (6e millénaire avant J.-C.) de Beg-an-Dorchenn (Bretagne, France) ont été étudiés afin d'évaluer leur période de collecte et de fournir un aperçu des reconstructions des paléo-températures. Les coquilles sectionnée...

The Manila clam (Ruditapes philippinarum) is the second most exploited bivalve in the world but remains threatened by diseases and global changes. Their associated microbiota play a key role in their fitness and acclimation capacities. This study aimed at better understanding the behavior of clam digestive glands and extrapallial fluids microbiota...

The Manila clam ( Ruditapes philippinarum) is the second most exploited bivalve in the world but remains threatened by diseases and global changes. Their associated microbiota play a key role in their fitness and acclimation capacities. This study aimed at better understanding the behavior of clam digestive glands and extrapallial fluids microbiota...

In bivalves, no clear-cut functional role of microbiota has yet been identified, although many publications suggest that they could be involved in nutrition or immunity of their host. In the context of climate change, integrative approaches at the crossroads of disciplines have been developed to explore the environment-host-pathogen-microbiota syst...

Environmental Vibrio strains represent a major threat in aquaculture, but the understanding of their virulence mechanisms heavily relies on the transposition of knowledge from human‐pathogen vibrios. Here, the genetic bases of the virulence of Vibrio harveyi ORM4 toward the European abalone Haliotis tuberculata were characterized. We demonstrated t...

Vibrio tapetis is a Gram-negative bacterium that causes infections of mollusk bivalves and fish. The Brown Ring Disease (BRD) is an infection caused by V. tapetis that primarily affects the Manila clam Ruditapes philippinarum . Recent studies have shown that a type IV secretion system (T4SS) gene cluster is exclusively found in strains of V. tapeti...

In mollusk aquaculture, a large number of Vibrio species are considered major pathogens. Conventional methods based on DNA amplification and sequencing used to accurately identify Vibrio species are unsuitable for monitoring programs because they are time-consuming and expensive. The aim of this study was, therefore, to develop the MALDI-TOF MS met...

Article available here -> https://authors.elsevier.com/a/1bTmjACeY5HTA Vibrio tapetis, the etiological agent of Brown Ring Disease, mainly affects the Manila clam Ruditapes philippinarum. Although this bacterium is mainly known as a clam pathogen, it has been isolated from several fish species. The main aim of the present study was to further explo...

The Manila clam Ruditapes philippinarum, a major cultured shellfish species, is threatened by infection with the microparasite Perkinsus olseni, whose prevalence increases with high water temperatures. Under the current trend of climate change, the already severe effects of this parasitic infection might rapidly increase the frequency of mass morta...

Ocean frontal systems are widespread hydrological features defining the transition zone between distinct water masses. They are generally of high biological importance as they are often associated with locally enhanced primary production by phytoplankton. However, the composition of bacterial communities in the frontal zone remains poorly understoo...

Aims: Brown Ring Disease (BRD) is an infection of the Manila clam Ruditapes philippinarum due to the pathogen Vibrio tapetis. During BRD, clams are facing immunodepression and shell biomineralization alteration. In this paper, we studied the role of pH on the growth of the pathogen and formulated hypothesis on the establishment of BRD by V. tapetis...

Digestive microbiota provides a wide range of beneficial effects on host physiology and are therefore likely to play a key role in marine intertidal bivalve ability to acclimatize to the intertidal zone. This study investigated the effect of intertidal levels on the digestive bacterial microbiota of oysters Crassostrea gigas and clams Ruditapes phi...

Paillard C. Faure D. Orlando L. Le séquençage à haut débit ouvre les archives fossiles de l’ADN ancien, dans 101 secrets de l’ADN. CNRS Editions. Editeurs D Faure, D. Joly, S Salamitou. 368 pages. 2019. ⟨ hal−02370904⟩

Marine mollusk aquaculture has more than doubled over the past twenty years, accounting for over 15% of total aquaculture production in 2016. Infectious disease is one of the main limiting factors to the development of mollusk aquaculture, and the difficulties inherent to combating pathogens through antibiotic therapies or disinfection have led to...

Marine mollusk aquaculture has more than doubled over the past twenty years, accounting for over 15% of total aquaculture production in 2016. Infectious disease is one of the main limiting factors to the development of mollusk aquaculture, and the difficulties inherent to combating pathogens through antibiotic therapies or disinfection have led to...

The Brown Ring Disease is an infection caused by the bacterium Vibrio tapetis on the Manila clam Ruditapes philippinarum. The process of infection, in the extrapallial fluids (EPFs) of clams, involves alteration of immune functions, in particular on hemocytes which are the cells responsible of phagocytosis. Disorganization of the actin-cytoskeleton...

Infectious agents such as the bacteria Vibrio aestuarianus or Ostreid herpesvirus 1 (OsHV‐1) have been repeatedly associated with dramatic disease outbreaks of Crassostrea gigas beds in Europe. Beside roles played by these pathogens microbial infections in C. gigas may derive from the contribution of a larger number of microorganisms than previousl...

Marine pathogenic bacteria are able to form biofilms on many surfaces, such as mollusc shells, and they can wait for the appropriate opportunity to induce their virulence. Vibrio tapetis can develop such biofilms on the inner surface of shells of the Ruditapes philippinarum clam, leading to the formation of a brown conchiolin deposit in the form of...

Ocean acidification is a major global stressor that leads to substantial changes in seawater carbonate chemistry, with potentially significant consequences for calcifying organisms. Marine shelled mollusks are ecologically and economically important species providing essential ecosystem services and food sources for other species. Because they use...

Vibrio campbellii BAA-1116 is renowned for its bioluminescence properties, and genetic tools are available to genetically track this strain. However, many other ecologically important V. harveyi strains exist, for which only few genetic tools are available. In this study, a rapid electroporation protocol was developed to transform replicative plasm...

Stable associations between marine invertebrates and their chemosynthetic bacterial symbionts are predicated on both the adequate transfer of resources and the restriction of bacterial cells to a finite population within host tissues. In symbioses between thyasirid bivalves and thiotrophic bacteria, symbionts are extracellular, acquired from a free...

The Brown Ring Disease (BRD) caused high mortality rates since 1986 in the Manila clam Venerupis philippinarum introduced and cultured in Western Europe from the 1970s. The causative agent of BRD is a Gram-Negative bacterium, Vibrio tapetis, which is also pathogenic to fish. Here we report the first assembly of the complete genome of V. tapetis CEC...

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 mul...

Marine mollusc shells enclose a wealth of information on coastal organisms and their environment. Their life history traits as well as (palaeo-) environmental conditions, including temperature, food availability, salinity, and pollution, can be traced through the analysis of their shell (micro-) structure and biogeochemical composition. Adding to t...

Since 1997, populations of the European abalone Haliotis tuberculata suffer mass mortalities attributed to the bacterium Vibrio harveyi. These mortalities occur at the spawning season, when the abalone immune system is depressed, and when temperatures exceed 17 °C, leading to favorable conditions for V. harveyi proliferation. In order to identify m...

VIVALDI, A H2020 EUROPEAN PROJECT AIMING AT PREVENTING ET MITIGATING FARMED BIVALVE DISEASES Isabelle Arzul1*, Stephen Feist2, Antonio Figueras3, Sylvie Lapègue1, Christine Paillard4 and Dolors Furones5 1 Ifremer, SG2M, France 2 CEFAS, United Kingdom 3 CSIC, Instituto Investigaciones Marinas, Spain 4 IUEM, UMR CNRS 6539, France 5 IRTA, Spain THE...

Abstract : Brown Ring Disease (BRD) is used as a case study to describe an ecological approach to understanding host-pathogen interactions. BRD is caused by a bacterial microparasite, Vibrio tapetis, which elicits the inhibition of the calcification process. Epidemiological studies of BRD are facilitated by the use of characteristic clinic signs on...

The Gram-negative bacterium Vibrio tapetis is known as the causative agent of Brown Ring Disease (BRD) in the Manila clam Venerupis (= Ruditapes ) philippinarum . This bivalve is the second most important species produced in aquaculture and has a high commercial value. In spite of the development of several molecular methods, no survey has been yet...

Photography of the 18 incubation tanks

Abstract The wide polarity range and highly polar compounds of two selected red seaweed, Grateloupia turuturu and Palmaria palmata, were extracted using two different types of solvent, dichloromethane/methanol and methanol/water. Monthly in vitro antibacterial activities were studied using the microplate method against the marine bacteria Vibrio ha...

Vibrio tapetis is a marine bacterium causing Brown Ring Disease (BRD) in the Manila clam Ruditapes philippinarum. V. tapetis biofilm formation remains unexplored depite the fact that it might be linked to pathogenicity. Our objectives were to characterize the in vitro biofilm formation of V. tapetis and evaluate the effects of culture conditions. B...

Tréguier A.M., Floc’H-Laizet C., 22 others, Paulet Y.M. and V. Pichereau, 2015.- LabexMER, A changing Ocean; 2012-2014 report. 90 p. available at http://www.labexmer.eu/fr/en/labexmer-2012-2014-report.pdf. Abstract: The cluster of excellence LabexMER was created in November 2011 in the framework of the French “investments for the future” program....

Since late 1980’s, manila clams (Ruditapes philippinarum) have been affected by the Brown Ring Disease (BRD) caused by Vibrio tapetis. Although several studies have investigated the effects of environmental parameters such as salinity, temperature, and sediment on this host-pathogen relationship, the effect of food quality has never been investigat...

Brown Ring Disease (BRD) is a bacterial infection affecting the economically-important clam Ruditapes philippinarum. The disease is caused by a bacterium, Vibrio tapetis, that colonizes the edge of the mantle, altering the biomineralization process and normal shell growth. Altered organic shell matrices accumulate on the inner face of the shell lea...

Vibrio tapetis causes the brown ring disease in the Japanese clam Ruditapes philippinarum while Vibrio aestuarianus is associated with massive oyster mortalities. As extracellular proteins are often associated with the virulence of pathogenic bacteria, we undertook a proteomic approach to characterize the secretomes of both vibrios. The extracellul...

Vibrio tapetis CECT4600 is a pathogenic Gram-negative bacterium causing the brown ring disease in the Manila clam Ruditapes philippinarum. This vibriosis is induced by bacterial attachment on the periostracal lamina, yielding a decalcification of the bivalve shell. As in many bacterial species, pathogenesis is likely related to biofilm formation. T...

Introduction World aquaculture production of molluscs, with an average in 2011 of 14.4 million tonnes, is the second fastest growing aquaculture sector in the world (FAO). But diseases in this sector are now a primary constraint, impeding the aquaculture development in many countries (Subasinghe et al. 2009). An important example is the bacteria Vi...

Vibrio harveyi is a marine bacterial pathogen responsible for episodic epidemics generally associated with massive mortalities in many marine organisms, including the European abalone Haliotis tuberculata. The aim of this study was to identify the portal of entry and the dynamics of infection of V. harveyi in the European abalone. The results indic...

Increasing temperature of seawater is often associated with increased exposure incidence of disease in field and in aquaculture populations. Numerous episodic mass mortalities of the abalone Haliotis tuberculata have been observed along the northern Brittany coast of France caused by a complex interaction between the host, patho- gen and environmen...

Coastal zones and the biosphere as a whole show signs of cumulative degradation due to the use and disposal of plastics. To better understand the manifestation of plastic pollution in the Atlantic Ocean, we partnered with local communities to determine the concentrations of micro-plastics in 125 beaches on three islands in the Canary Current: Lanza...

Wild or farmed abalone are regularly exposed to stressors, such as air exposure and handling. Immune and transcriptional responses as well as susceptibility to vibriosis of sexually mature or immature European abalone acclimated at 16 or 19°C were determined following handling or air exposure. Hemocyte density and H2O2 production increased while he...

Haemolymph-associated microbiota of marine bivalves was explored for antibacterial activity against important aquaculture pathogens. A collection of 843 strains were cultured from the haemolymph of four bivalve species (Crassostrea gigas, Mytilus edulis, Pecten maximus and Tapes rhomboides) collected by deep-sea diving in the Glenan Archipelago (Fr...

Manila clams, Venerupis philippinarum (Adams and Reeve, 1850), were experimentally challenged with two Vibrio tapetis strains, V. tapetis strain CECT4600 the causative agent of Brown Ring Disease (BRD) and V. tapetis strain LP2 supposed to be non-pathogenic to V. philippinarum. Changes in phenoloxidase (PO) and superoxide dismutase (SOD), two major...

Manila clams, Venerupis philippinarum (Adams and Reeve, 1850), were experimentally infected with two different bacterial strains at two different temperatures. Bacterial strains used in this study were Vibrio tapetis strain CECT4600, the causative agent of Brown Ring Disease (BRD) and V. tapetis strain LP2, supposed non pathogenic to V. philippinar...

Vibrio tapetis CECT4600 is a pathogenic bacterium causing the Brown Ring Disease in Manila clam Ruditapes philippinarum. This vibriosis is induced by bacterial adhesion on the periostracal lamina, yielding a decalcification of bivalve shell. As in many bacterial species, pathogenesis is likely related to biofilm formation. In this study, V. tapetis...

The decline of European abalone Haliotis tuberculata populations has been associated with various pathogens including bacteria of the genus Vibrio. Following the summer mortality outbreaks reported in France between 1998 and 2000, Vibrio harveyi strains were isolated from moribund abalones, allowing in vivo and in vitro studies on the interactions...

Brown ring disease (BRD) is a bacterial infection affecting the economically-important clam Ruditapes philippinarum. The disease is caused by a bacterium, Vibrio tapetis, that colonizes the edge of the mantle, altering the biomineralization process and normal shell growth. Altered organic shell matrices accumulate on the inner face of the shell lea...