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| Registros recuperados: 34 | |
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| Cumming, Graeme S.; Percy FitzPatrick Institute, DST/NRF Center of Excellence, University of Cape Town, Rondebosch, 7701, South Africa; graeme.cumming@uct.ac.za; Hockey, Philip A. R.; Percy FitzPatrick Institute, DST/NRF Center of Excellence, University of Cape Town, Rondebosch, 7701, South Africa; phil.hockey@uct.ac.za; Bruinzeel, Leo W.; Percy FitzPatrick Institute, DST/NRF Center of Excellence, University of Cape Town, Rondebosch, 7701, South Africa; lbruinze@adu.uct.ac.za; Du Plessis, Morne A.; Percy FitzPatrick Institute, DST/NRF Center of Excellence, University of Cape Town, Rondebosch, 7701, South Africa; mornedup@vodamail.co.za. |
| Global analyses of the potential for avian influenza transmission by wild birds have ignored key characteristics of the southern African avifauna. Although southern Africa hosts a variety of migratory, Holarctic-breeding wading birds and shorebirds, the documented prevalence of avian influenza in these species is low. The primary natural carriers of influenza viruses in the northern hemisphere are the anatids, i.e., ducks. In contrast to Palearctic-breeding species, most southern African anatids do not undertake predictable annual migrations and do not follow migratory flyways. Here we present a simple, spatially explicit risk analysis for avian influenza transmission by wild ducks in southern Africa. We developed a risk value for each of 16 southern... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Anatidae; Avian influenza; Botswana; Ducks; Influenza; Landscape ecology; Namibia; Pathogen; South Africa; Virus; Waterfowl; Zimbabwe.. |
| Ano: 2008 |
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| Cumming, Graeme S.; Percy FitzPatrick Institute, DST/NRF Centre of Excellence, University of Cape Town; graeme.cumming@uct.ac.za. |
| Pathogen dynamics are inseparable from the broader environmental context in which pathogens occur. Although some pathogens of people are primarily limited to the human population, occurrences of zoonoses and vector-borne diseases are intimately linked to ecosystems. The emergence of these diseases is currently being driven by a variety of influences that include, among other things, changes in the human population, long-distance travel, high-intensity animal-production systems, and anthropogenic modification of ecosystems. Anthropogenic impacts on ecosystems have both direct and indirect (food-web mediated) effects. Therefore, understanding disease risk for zoonoses is a social–ecological problem. The articles in this special feature focus on... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Disease; Framework; Health; Influenza; Pathogen; Resilience; Social– Ecological system. |
| Ano: 2010 |
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| Oliveira,Ademir Kleber M; Rizzi,Elvia Silvia; Pereira,Kelly Cristina L; Bono,José Antônio M; Matias,José Carlos Pina; Rosemary. |
| ABSTRACT The use of plant extracts can be an alternative to reduce the use of pesticides, to control diseases and pests that affect agricultural production. The aim of this study was the chemical characterization of the extract and fractions of Pouteria ramiflora leaves and to determine its fungistatic potential on Lasiodiplodia theobromae. The ethanolic extract of dried and crushed leaves was obtained by maceration. Part of this extract was sequentially partitioned and the following fractions were obtained: hexane, dichloromethane, chloroform, ethyl acetate, n-butyl, and hydromethanol for subsequent bioassay, and qualitative and quantitative phytochemical analysis. Experimental development comprises of adding a L. theobromae mycelial disk (5 mm), obtained... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pathogen; Natural products; Organic farming; Flavonoids. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362017000400564 |
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| Pernet, Fabrice; Lugue, Klervi; Petton, Bruno. |
| Competition between organisms interfere in host and pathogen dynamics in ways that are difficult to predict. By one side, competitors can reduce the food supply and cause nutritional stress. Such stress could further modulate the susceptibility to infection by altering immune response or metabolic rate of the host. Alternatively, competitors may trap pathogens before they reach the focal host, and therefore reduce, enhance, or have no effect on infection according to the competitor's susceptibility to the infection. To better understand how competition influences host and pathogen interactions, we experimentally assessed the relative importance of competition for pathogens and resources on the severity of a viral disease infecting the Pacific oyster... |
| Tipo: Text |
Palavras-chave: Competition; Crassostrea gigas; Disease ecology; Filtration; Ostreid herpesvirus 1; Pathogen. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00692/80375/83493.pdf |
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| Saulnier, Denis; De Decker, Sophie; Haffner, Philippe. |
| Because Vibrio aestuarianus is known to cause serious infections in Pacific oyster Crassostrea gigas, a real-time PCR assay was developed targeting the dnaJ gene of this bacterium. Only V. aestuarianus strains isolated from C. gigas mortality events in different geographic areas and the reference strain tested positive, whereas no amplification products was obtained with type strains belonging to 23 other species of Vibrio. Sensitivity and reproducibility of the method were assessed using either seawater or oyster homogenate samples spiked with one V aestuarianus strain. All these samples were stored at -20 degrees C in order to mimic retrospective or grouped natural sample analysis without quantification bias due to prolonged freezing. Analysis of... |
| Tipo: Text |
Palavras-chave: V. aestuarianus; Vibrio; Taqman; Real time PCR; Pathogen; Oyster; Crassostrea gigas. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6447.pdf |
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| Goarant, Cyrille; Reynaud, Yann; Ansquer, Dominique; De Decker, Sophie; Merien, Fabrice. |
| In a previous study, we demonstrated the existence of an emerging cluster of Vibrio nigripulchritudo that proved to be associated with shrimp mortality events in New Caledonia. Using sequence polymorphisms evidenced in this previous MultiLocus Sequence Typing study, we developed two new quantitative PCR assays permitting the detection and quantification of V. nigripulchritudo at the genospecies level using SYBR Green I chemistry and at the emerging cluster level using Fluorescence Resonance Energy Transfer technology with hybridization probes. The use of this molecular diagnostic tool evidenced the colonization of the shrimp pond ecosystem by the pathogenic cluster at least at the onset of the disease. This new tool will allow better investigation of the... |
| Tipo: Text |
Palavras-chave: Shrimp; Cluster specific; Vibrio; Pathogen; Mariculture; Real time PCR. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2729.pdf |
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| Le Guyader, Soizick; Atmar, Robert; Maalouf, Haifa; Le Pendu, Jacques. |
| Shellfish can be a vector for human pathogens. Despite regulation based on enteric bacteria, shellfish are still implicated in viral outbreaks. Oysters are the most common shellfish associated with outbreaks, and noroviruses, which cause acute gastroenteritis, are the most frequently identified pathogen in these outbreaks. Analysis of shellfish-related outbreak data worldwide shows an unexpected high proportion of NoV GI strains. Recent studies performed in vitro, in vivo and in the environment indicate that oysters are not just a passive filter, but can selectively accumulate norovirus strains based on virus carbohydrate ligands shared with humans. These observations may help explain the GI/GII bias observed in shellfish-related outbreaks compared to... |
| Tipo: Text |
Palavras-chave: Shellfish; Noroviruses; Oyster contamination; Pathogen. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00150/26093/24313.pdf |
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| Le Guyader, Soizick; Loisy, Fabienne; Atmar, R; Hutson, A; Estes, M; Ruvoen-clouet, N; Pommepuy, Monique; Le Pendu, J. |
| The primary pathogens related to shellfishborne gastroenteritis outbreaks are noroviruses. These viruses show persistence in oysters, which suggests an active mechanism of virus concentration. We investigated whether Norwalk virus or viruslike particles bind specifically to oyster tissues after bioaccumulation or addition to tissue sections. Since noroviruses attach to carbohydrates of the histo-blood group family, tests using immunohistochemical analysis were performed to evaluate specific binding of virus or viruslike particles to oyster tissues through these ligands. Viral particles bind specifically to digestive ducts (midgut, main and secondary ducts, and tubules) by carbohydrate structures with a terminal N-acetylgalactosamine residue in an alpha... |
| Tipo: Text |
Palavras-chave: Bioaccumulation; Shellfish; Escherichia coli; Pathogen; Oyster digestive tissue; Noroviruses. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1542.pdf |
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| Soletchnik, Patrick; Goulletquer, Philippe; Cochennec, Nathalie; Renault, Tristan; Geairon, Philippe. |
| A population of Pacific ovsters, Crassostrea gigas, infected with a Chlamydia-like procaryote was reared to compare infection trends under three different feeding conditions: a starved condition, an intermediate condition with a diet of Skeletonema costatllm, and a mixed algal diet. Several physiological and pathological criteriJ: presence of gill abnormality; microscopic examination, basophilic intracytoplasmic inclusions, Feulgen reaction; condition index, filtration, food consumptiQn; fecal production and respiration were used to compare the various modalities one month after the initiation of the experiment. The Irodality of starved oysters showed reduce physiological performances in terms of scope for growth and condition index compared to oysters... |
| Tipo: Text |
Palavras-chave: Pathogen; Chlamydia; Procaryote; Crassostrea gigas; Oyster; Ecophysiology; Pathogène; Chlamydia; Procaryote; Crassostrea gigas; Huître; Ecophysiologie. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-2741.pdf |
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| Berthe, Franck. |
| In 1999, the world aquaculture production of molluscs was estimated at 9.4 million tonnes which represents approximately a 23% contribution to the global aquaculture production. Aquaculture of molluscs has been growing at an average annual rate of 11% over the past decades, although some activities - such as aquaculture of pectens or abalones - were growing even more rapidly. In many countries, there is a significant mollusc aquaculture, traditionally based on wild stocks. However, these natural populations frequently do not fulfil market demand, because of low value of the product, over-fishing of the resource and/or mass mortality outbreaks caused by diseases. A frequent answer to this situation has been the introduction of new stocks or new species in... |
| Tipo: Text |
Palavras-chave: Mortality; Mollucs; Pathogen. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-2780.pdf |
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| Garnier, Matthieu; Labreuche, Yannick; Nicolas, Jean-louis. |
| Eleven Vibrio isolates invading the hemolymph of live and moribund oysters (Crassostrea gigas) collected in the field and from a hatchery in France, were characterized by a polyphasic approach. Phylogenetic analysis of 16S rRNA, gyrB and toxR genes indicated high homogeneity between these strains and the Vibrio aestuarianus type strain (ATCC35048(T)), and confirmed previous 16S rRNA analysis. In contrast, DNA:DNA hybridization was from 61% to 100%, while phenotypic characters and virulence tests showed a large diversity between the strains. Nevertheless, several common characters allowed the isolates to be distinguished from the reference strain. On the basis of several distinct phenotypic characteristics, it is proposed to establish two subspecies within... |
| Tipo: Text |
Palavras-chave: Polyphasic approach; Summer mortalities; Crassostrea gigas; Pathogen; French isolates; Vibrio aestuarianus. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4961.pdf |
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| Gatesoupe, Joel. |
| Many recent papers have deepened the state of knowledge about lactic acid bacteria (LAB) in fish gut. In spite of high variability in fish microbiota, LAB are sometimes abundant in the intestine, notably in freshwater fish. Several strains of Streptococcus are pathogenic to fish. S. iniae and Lactococcus garvieae are major fish pathogens, against which commercial vaccines are available. Fortunately, most LAB are harmless, and some strains have been reported for beneficent effects on fish health. A major step forward of the recent years was those converging evidences that LAB can stimulate the immune system in fish. An open question is whether viability can affect immunostimulation. The issue is crucial to commercialise live probiotics rather than... |
| Tipo: Text |
Palavras-chave: Probiotic; Pathogen; Lactic acid bacteria; Gastrointestinal microbiota; Fish. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2589.pdf |
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| Lassalle, Damien; Tetreau, Guillaume; Pinaud, Silvain; Galinier, Richard; Crickmore, Neil; Gourbal, Benjamain; Duval, David. |
| Biomphalaria glabrata is a freshwater Planorbidae snail. In its environment, this mollusk faces numerous microorganisms or pathogens, and has developed sophisticated innate immune mechanisms to survive. The mechanisms of recognition are quite well understood in Biomphalaria glabrata, but immune effectors have been seldom described. In this study, we analyzed a new family of potential immune effectors and characterized five new genes that were named Glabralysins. The five Glabralysin genes showed different genomic structures and the high degree of amino acid identity between the Glabralysins, and the presence of the conserved ETX/MTX2 domain, support the hypothesis that they are pore-forming toxins. In addition, tertiary structure prediction confirms that... |
| Tipo: Text |
Palavras-chave: Pore-forming toxin; Cry toxin; Invertebrate; Biomphalaria glabrata; Host; Pathogen; Vector snail; Innate immunity. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00601/71267/69655.pdf |
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| Lassudrie Duchesne, Malwenn; Hegaret, Helene; Wikfors, Gary H; Mirella Da Silva, Patricia. |
| Bivalves were long thought to be “symptomless carriers” of marine microalgal toxins to human seafood consumers. In the past three decades, science has come to recognize that harmful algae and their toxins can be harmful to grazers, including bivalves. Indeed, studies have shown conclusively that some microalgal toxins function as active grazing deterrents. When responding to marine Harmful Algal Bloom (HAB) events, bivalves can reject toxic cells to minimize toxin and bioactive extracellular compound (BEC) exposure, or ingest and digest cells, incorporating nutritional components and toxins. Several studies have reported modulation of bivalve hemocyte variables in response to HAB exposure. Hemocytes are specialized cells involved in many functions in... |
| Tipo: Text |
Palavras-chave: Bivalve; Harmful algal blooms (HABs); Pathogen; Hemocyte; Disease. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72401/71346.pdf |
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| Degremont, Lionel; Garcia, Celine; Allen, Standish K., Jr.. |
| Oyster species suffer from numerous disease outbreaks, often causing high mortality. Because the environment cannot be controlled, genetic improvement for disease resistance to pathogens is an attractive option to reduce their impact on oyster production. We review the literature on selective breeding programs for disease resistance in oyster species, and the impact of triploidy on such resistance. Significant response to selection to improve disease resistance was observed in all studies after two to four generations of selection for Haplosporidium nelsoni and Roseovarius crassostrea in Crassostrea virginica, OsHV-1 in Crassostrea gigas, and Martelia sydneyi in Saccostrea glomerata. Clearly, resistance in these cases was heritable, but most of the studies... |
| Tipo: Text |
Palavras-chave: Disease resistance; Oyster; Selection; Pathogen; Genetic; Mortality. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00269/38049/36139.pdf |
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| Registros recuperados: 34 | |
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