Résumé : Ce document constitue le bilan détaillé des résultats du projet DEDUCTION (2007-2010) , action par action. Le projet DEDUCTION "DEveloppement DUrable de la Crevetticulture, Traitement de l’Information et Observatoire du système en Nouvelle-Calédonie" est un projet de recherche et de développement en soutien à la filière crevetticole néo-calédonienne. C'est un programme très horizontal et pluridisciplinaire en poursuivant et développant les ouvertures scientifiques, techniques et thématiques établies à la faveur de DESANS. Son ossature s’articule autour de 4 actions : 3 actions de recherche et une action transversale devant faciliter les interfaces entre la recherche et sa finalité, entre les chercheurs et les partenaires locaux (GFA, Provinces, Gouvernement, Haut-Commissariat), en intégrant les résultats "ferme" à l'échelle de la filière. Une tâche de « Communication et de Transfert des connaissances » a été ajoutée en facteur commun des 4 actions scientifiques afin de répondre à la question fondamentale des échanges entre acteurs.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00199/31006/35663.pdf
http://archimer.ifremer.fr/doc/00199/31006/

Éditeur(s) : PSIC 11 - 11th Pacific Science Inter-Congress : Pacific Countries and their Ocean: Facing Local and Global Changes / 2nd Symposium on French Research in the Pacific. March 2 - 6, 2009 Tahiti, French Polynesia.
Résumé : Experimental infections together with epidemiological studies have shown that pathogenic and non‐pathogenic isolates of V. nigripulchritudo co‐existed in shrimp farm environment (2, 3). Moreover, obtained results also demonstrated that the “summer syndrome”was caused by a single, possibly emerging, cluster of virulent strains. Consequently, it was hypothesized that pathogenic strains of V. nigripulchritudo may persist from one year to the next in the shrimp farm environment and re‐develop inside the grow‐out system at the following rearing cycle (3). This study was therefore aimed at determining whether V. nigripulchritudo isolates may survive, or not, in a shrimp pond bottom soil during a 18‐week drying period. To this end, V.nigripulchritudo mapping was performed with recently developed molecular tools and classical culture‐dependent techniques.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00197/30874/29242.pdf
http://archimer.ifremer.fr/doc/00197/30874/

Résumé : Seawater, algae, micro-diets and Artemia are the main inputs in shrimp larval rearing. Each of them are potential carriers of pathogenic bacteria in the rearing media and weaken the animal in its early life stages. Daily monitoring of rearing water and larvae showed a bacterial spike after the first live feed meal. Vibrio settlement can be enhancedby giving Artemia with their incubation water where vibrio concentration can reach up to 105 CFU per milliliter. This study showed that simple measures such as rinsing and supplying Artemia with freshwater allowed a significant drop in their bacterial load.
L’élevage larvaire de crevettes nécessite l’utilisation de plusieurs intrants que sont l’eau de mer, les algues, les micro-particules et les Artemia. Chacun de ces intrants peut être une porte d’entrée potentielle de bactéries pathogènes et affaiblir l’animal dans les stades précoces. Des analyses bactériennes de l’eau d’élevage et des larves au quotidien montrent que c’est après l’introduction des proies vivantes que la flambée bactérienne est observée. La présence de vibrio peut être favorisée par la distribution des artémies dans leur eau d’incubation où il a pu être dénombré jusqu’à 105 CFU/ml. Cette fiche biotechnique montre qu’une mesure simple et efficace telle que le rinçage et la distribution des proies vivantes dans l’eau douce permet de réduire significativement la quantité de bactéries apportée par les Artemia.

Droits : 2008 Ifremer
http://archimer.ifremer.fr/doc/00118/22971/20801.pdf
http://archimer.ifremer.fr/doc/00118/22971/

Éditeur(s) : The 11th Pacific Science Inter-Congress : Pacific Countries and their Ocean: Facing Local and Global Changes. March 2 - 6, 2009 Tahiti, French Polynesia
Résumé : New Caledonian shrimp farming feasibility studies started in the mid-seventies. Today ca. 2000 tons of Litopenaeus stylirostris, introduced in 1978, are semi-intensively produced each year. Since fifteen years, production has been impacted by two seasonal vibriosis, the “Summer” syndrome caused by Vibrio nigripulchritudo in relation to pond bottom and water column quality, and the “Winter Syndrome” caused by Vibrio penaeicida in relation to drastic temperature drops . With the ambition of elucidating processes possibly leading to mortality outbreaks in ponds, Ifremer has been conducting a research program since 2003 under the DESANS project (2003-2006) and the present DEDUCTION project, equally funded by the South and North Provinces and by the Government of New Caledonia. This program has been designed in a multidisciplinary approach integrating the suspected multifactorial origin of shrimp mortalities. Environment quality in ponds (either sediment or water column) plays a major role in the shrimp ecophysiological status, influencing sensitivity to pathogens . DEDUCTION focuses on a better knowledge of phytoplankton composition and biogeochemical fluxes at the sediment-water interface in ponds. Impact of farm discharges is also investigated. In addition, a more fundamental work is conducted to understand the pathogenicity mechanisms of these two Vibrio species but also to prevent the occurrence of viral infections through a RNA interference approach. Markers of the ecophysiological status of broodstock, larvae, post-larvae and reared animals, such as enzymes testifying from an oxidative stress, are developed. Gain of performance (resistance to pathogens and growth) were obtained on hybrids of the New Caledonian and introduced Hawaiian strains. Finally the database Stylog is exploited in view of discriminating “good” from “bad” rearings on the basis of relevant indicators.
Les études de faisabilité de l'aquaculture de crevettes ont débuté en Nouvelle-Calédonie dans les années soixante dix. Aujourd'hui environ 2000 tonnes de Litopenaeus stylirostris, introduite en 1978, sont produites chaque année de façon semi-intensive. Depuis quinze ans la production a été impactée par deux vibrioses : le syndrome d'été provoqué par Vibrio nigripulchritudo en relation avec la qualité de la tranche d'eau et des fonds de bassins et le syndrome d'hiver provoqué par Vibrio penaeicida en relation avec des chutes rapides de température. Dans le but d'élucider les processus entrainant des mortalités dans les élevages, Ifremer a conduit un programme de recherche depuis 2003 dans le cadre du projet DESANS (2003-2006) puis du présent projet DEDUCTION co-financé par les provinces Nord et Sud et le Gouvernement de la Nouvelle-Calédonie. Ce programme se construit dans une démarche multidisciplinaire intégrant les origines supposées multifactorielles des mortalités de crevettes. La qualité environnementale dans les bassins (les fonds et la colonne d'eau) joue un rôle majeur dans l'état physiologique des animaux, influençant leur sensibilité aux pathogènes. DEDUCTION se focalise sur une meilleure compréhension de la composition phytoplanctonique et des flux bio-géochimiques à l'interface eau/sédiment dans les bassins.L'impact des rejets des fermes est également étudié. En outre, un travail plus fondamental est conduit pour connaître les mécanismes de pathogénicité de ces deux espèces de Vibrio mais aussi pour prévenir les occurences d'infections virales par des approches ARN Interférence. Des marqueurs de l'état physiologique des oeufs, larves, post-larves et animaux en élevage, tels que les enzymes du stress oxydant sont utilisés.Les gains de performance (résistance aux pathogènes et croissance) sont obtenus sur des hybrides issus du croisement de la souche locale avec une souche hawaienne. Finalement la base de données STYLOG est exploitée dans le but de distinguer les bonnes des mauvaises pratiques sur la base d'indicateurs fiables.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00143/25438/23591.pdf
http://archimer.ifremer.fr/doc/00143/25438/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
: Previously, we demonstrated that eicosapentaenoic acid enhanced ethanol-induced oxidative stress and cell death in primary rat hepatocytes via an increase in membrane fluidity and lipid raft clustering. In this context, another n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), was tested with a special emphasis on physical and chemical alteration of lipid rafts. Pretreatment of hepatocytes with DHA reduced significantly ethanol-induced oxidative stress and cell death. DHA protection could be related to an alteration of lipid rafts. Indeed, rafts exhibited a marked increase in membrane fluidity and packing defects leading to the exclusion of a raft protein marker, flotillin. Furthermore, DHA strongly inhibited disulfide bridge formation, even in control cells, thus suggesting a disruption of protein-protein interactions inside lipid rafts. This particular spatial organization of lipid rafts due to DHA subsequently prevented the ethanol-induced lipid raft clustering. Such a prevention was then responsible for the inhibition of phospholipase C-γ translocation into rafts, and consequently of both lysosome accumulation and elevation in cellular low-molecular-weight iron content, a prooxidant factor. In total, the present study suggests that DHA supplementation could represent a new preventive approach for patients with alcoholic liver disease based upon modulation of the membrane structures.
ISSN: 0278-6915

hal-00860153
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860153
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860153/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860153/file/Sergent-et-al-incl-figures-accepted.pdf
DOI : 10.1016/j.fct.2013.07.061

Éditeur(s) : HAL CCSD American Academy of Neurology
Résumé : International audience
OBJECTIVE: We examined if the CNS Penetration-Effectiveness (CPE) score of antiretroviral drugs was associated with survival after a diagnosis of HIV-related encephalopathy, progressive multifocal leukoencephalopathy (PML), cerebral toxoplasmosis, or cryptococcal meningitis. METHODS: Using data from the FHDH-ANRS CO4, we compared the survival of 9,932 HIV-infected patients diagnosed with a first neurologic AIDS-defining event in the pre-combination antiretroviral therapy (cART) (1992-1995), early cART (1996-1998), or late cART (1999-2004) periods. Follow-up was subdivided (CPE < 1.5 and CPE ≥ 1.5), and relative rates (RR) of death were estimated using multivariable Poisson regression models. RESULTS: In the pre-cART and early cART periods, regimens with CPE ≥ 1.5 were associated with lower mortality after HIV-related encephalopathy (RR 0.64; 95% confidence interval [CI] 0.47-0.86 and RR 0.45; 95% CI 0.35-0.58) and after PML (RR 0.79; 95% CI 0.55-1.12 and RR 0.45; 95% CI 0.31-0.65), compared to regimens with CPE < 1.5, while in the late cART period there was no association between the CPE score and the mortality. A higher CPE score was also associated with a lower mortality in all periods after cerebral toxoplasmosis (RR 0.68, 95% CI 0.56-0.84) or cryptococcal meningitis (RR 0.50, 95% CI 0.34-0.74). Whatever the neurologic event, these associations were not maintained after adjustment on updated plasma HIV-RNA (missing, <500, ≥500 copies/mL) with RR ranging from 0.82 (95% CI 0.36-1.91) to 1.02 (0.69-1.52). CONCLUSION: At the beginning of the cART era, the CPE score was of importance for survival after severe neurologic event, while in the late cART period, the additional effect of CPE score vanished with more powerful antiretroviral regimens associated with plasma viral load control.
ISSN: 0028-3878

hal-00875434
https://hal.archives-ouvertes.fr/hal-00875434
DOI : 10.1212/WNL.0b013e31820c3089
PUBMED : 21248274

Éditeur(s) : HAL CCSD
Résumé : International audience
Reports on dengue morbidity in patients with sickle cell disease (SCD) are scarce. Dengue is arthropod-borne viroses due to dengue virus (DENV) and affects populations with a high prevalence of SCD; therefore, the risk of morbidity may be increased.To determine the impact of dengue infection in SCD patients, we reviewed medical records during a vast outbreak of dengue virus serotype-2 (DENV-2) in French Guiana in 2012-2013. We identified 10 cases of laboratory-confirmed dengue infection;these were classified into A, B and C categories based on levels of severity of dengue according to World Health Organisation (WHO). The average age of SCD patients was 18.2 years. 1, 6 and 3 cases were classified as A, B and C WHO severity criteria, respectively. All patients had an important decrease in haematocrit (while one of the WHO severity criteria is the increase of haematocrit). Only one patient had decreased platelet count. Seven cases had vaso-occlusive crisis (VOC), six patients developed acute hepatitis and eight had a simultaneous bacterial infection. Six of them needed a blood transfusion. The results suggested that the WHO severity laboratory criteria of hemoconcentration and platelet counts were not helpful in themanagement of SCD patients. The morbidity was mainly caused by specific complications of SCD, especially VOC, likely facilitated by vascular endothelial damages consecutive to dengue fever, severe haemolysis, hepatitis and bacterial co-infections.
Journal of Virology and Retrovirology

Droits : info:eu-repo/semantics/OpenAccess
inserm-01419456
http://www.hal.inserm.fr/inserm-01419456
http://www.hal.inserm.fr/inserm-01419456/document
http://www.hal.inserm.fr/inserm-01419456/file/2015%2C%20Mosnier%20-%20Dengue%20infection%20in%20sickle%20cell%20patients%20in%20French%20Guiana.pdf

Éditeur(s) : Wiley-blackwell Publishing, Inc
Résumé : Aims: A description of bacterial pathogens in shrimp ponds is necessary to understand their pathogenesis. Vibrio nigripulchritudo was shown to contain saprophytic and pathogenic strains among New Caledonian isolates. We established a method to map the development of V. nigripulchritudo in pond sediments at three different genetic levels: the species level, then at the pathogenic cluster level and finally at the plasmid level, present only in all highly pathogenic isolates. Methods and Results: PCR methods were applied to shrimp pond sediments both before and after a mortality outbreak. Using crude samples, the species V. nigripulchritudo is not detected at first (0/42 samples at day 56 post stocking) but appears frequently in the sediments after the mortality event (30/42 at day 107). The distribution of strains from the pathogenic cluster of V. nigripulchritudo also follows this pattern. In contrast, the pSFn1 virulence-associated plasmid was detected in one sample at day 56 and none at day 107. An enrichment method was developed to lower the detection limits of our assays. After enrichment, the species V. nigripulchritudo was detected in all samples at both dates. The number of samples positive for pSFn1 was 42/42 samples at day 56 and 29/42 at day 107. Conclusions: These results show that the sediments contain V. nigripulchritudo, notably pathogenic strains. Surprisingly, the virulence-associated plasmid pSFn1 found in all V. nigripulchritudo isolated from moribund shrimp appears less frequently in sediments, possibly being useless or even detrimental to its recipient bacteria in this environment. Significance and Impact of the Study: This study confirms the presence of pathogenic V. nigripulchritudo strains in shrimp pond sediment before a mortality outbreak complying with a previous hypothesis that sediments could be the infecting reservoir. After the outbreak, both total V. nigripulchritudo and pathogenic strains populations have largely increased, possibly contributing to the recurrent mortality observed in this shrimp vibriosis.
Journal Of Applied Microbiology (1364-5072) (Wiley-blackwell Publishing, Inc), 2010-06 , Vol. 108 , N. 6 , P. 2003-2011

Droits : 2010 The Society for Applied Microbiology - Wiley-Blackwell
http://archimer.ifremer.fr/doc/00004/11484/8177.pdf
DOI:10.1111/j.1365-2672.2009.04601.x
http://archimer.ifremer.fr/doc/00004/11484/

Éditeur(s) : HAL CCSD Lippincott, Williams & Wilkins
Résumé : International audience
OBJECTIVES: The ANRS-112 INTERPRIM trial assessed whether fixed-cycles of antiretroviral treatment interruption (ART-STI) combined or not with pegylated interferon alpha-2b (peg-IFN) could lower viral load and achieve a healthier immune system in patients diagnosed during primary HIV-1-infection (PHI). DESIGN AND METHODS: Patients were randomized to receive either continuous ART (cART) during 72 weeks, or cART during 36 weeks followed by three ART-STIs, or the same ART-STIs associated with peg-IFN during the first 14 weeks and each interruption (ART-STI-IFN). Treatment was stopped at week 72. Final evaluation was based on plasma HIV-RNA level 6 months after the last treatment interruption. RESULTS: Eighty-seven percent of patients achieved undetectable HIV-RNA at week 32, with no deleterious impact of sequential treatment interruptions (STIs). Viral rebounds during interruptions were lower in the ART-STI-IFN than in the ART-STI group and during the second and third interruptions compared with the first one. However, HIV-RNA levels, CD4 T-cell counts and CD4 T/CD8 T ratios were similar between groups after the 6-month interruption, with a persistent effect on CD4 T cells and total cell-associated HIV-DNA levels. Predictive factors of virological outcome were HIV-RNA and HIV-DNA levels at PHI and HIV-DNA levels at treatment interruption. HIV-specific responses did not differ between strategies and were not associated with outcome. Forty-eight percent of patients experienced treatment resumption during long-term follow-up without difference between groups. CONCLUSION: When initiated during PHI, STIs associated or not with IFN did not result in a different outcome as compared to cART. All regimens showed a high response rate and a sustained immunological benefit after cessation.
ISSN: 0269-9370

hal-00875175
https://hal.archives-ouvertes.fr/hal-00875175
DOI : 10.1097/QAD.0b013e32835844d9
PUBMED : 22842994

Éditeur(s) : HAL CCSD American College of Physicians
Résumé : International audience
BACKGROUND: Most clinical guidelines recommend that AIDS-free, HIV-infected persons with CD4 cell counts below 0.350 × 10(9) cells/L initiate combined antiretroviral therapy (cART), but the optimal CD4 cell count at which cART should be initiated remains a matter of debate. OBJECTIVE: To identify the optimal CD4 cell count at which cART should be initiated. DESIGN: Prospective observational data from the HIV-CAUSAL Collaboration and dynamic marginal structural models were used to compare cART initiation strategies for CD4 thresholds between 0.200 and 0.500 × 10(9) cells/L. SETTING: HIV clinics in Europe and the Veterans Health Administration system in the United States. PATIENTS: 20, 971 HIV-infected, therapy-naive persons with baseline CD4 cell counts at or above 0.500 × 10(9) cells/L and no previous AIDS-defining illnesses, of whom 8392 had a CD4 cell count that decreased into the range of 0.200 to 0.499 × 10(9) cells/L and were included in the analysis. MEASUREMENTS: Hazard ratios and survival proportions for all-cause mortality and a combined end point of AIDS-defining illness or death. RESULTS: Compared with initiating cART at the CD4 cell count threshold of 0.500 × 10(9) cells/L, the mortality hazard ratio was 1.01 (95% CI, 0.84 to 1.22) for the 0.350 threshold and 1.20 (CI, 0.97 to 1.48) for the 0.200 threshold. The corresponding hazard ratios were 1.38 (CI, 1.23 to 1.56) and 1.90 (CI, 1.67 to 2.15), respectively, for the combined end point of AIDS-defining illness or death. Limitations: CD4 cell count at cART initiation was not randomized. Residual confounding may exist. CONCLUSION: Initiation of cART at a threshold CD4 count of 0.500 × 10(9) cells/L increases AIDS-free survival. However, mortality did not vary substantially with the use of CD4 thresholds between 0.300 and 0.500 × 10(9) cells/L.
ISSN: 0003-4819

hal-00875307
https://hal.archives-ouvertes.fr/hal-00875307
PUBMED : 21502648
DOI : 10.7326/0003-4819-154-8-201104190-00001