Host-Seeking Activity of Bluetongue Virus Vectors: Endo/Exophagy and Circadian Rhythm of Culicoides in Western Europe

Feeding success of free-living hematophagous insects depends on their ability to be active when hosts are available and to reach places where hosts are accessible. When the hematophagous insect is a vector of pathogens, determining the components of host-seeking behavior is of primary interest for the assessment of transmission risk. Our aim was to describe endo/exophagy and circadian host-seeking activity of Palaearctic Culicoides species, which are major biting pests and arbovirus vectors, using drop traps and suction traps baited with four sheep, as bluetongue virus hosts. Collections were carried out in the field, a largely-open stable and an enclosed stable during six collection periods of 24 hours in April/May, in late June and in September/October 2010 in western France. A total of 986 Culicoides belonging to 13 species, mainly C. brunnicans and C. obsoletus, was collected on animal baits. Culicoides brunnicans was clearly exophagic, whereas C. obsoletus was able to enter stables. Culicoides brunnicans exhibited a bimodal pattern of host-seeking activity with peaks just after sunrise and sunset. Culicoides obsoletus was active before sunset in spring and autumn and after sunset in summer, thus illustrating influence of other parameters than light, especially temperature. Description of host-seeking behaviors allowed us to discuss control strategies for transmission of Culicoides-borne pathogens, such as bluetongue virus. However, practical vector-control recommendations are difficult to provide because of the variation in the degree of endophagy and time of host-seeking activity.This study was funded by CIRAD, by the Ministe`re de l’agriculture, de l’alimentation, de la peˆche, de la ruralite´ et de l’ame´nagement du terroire and by the EU FP7-HEALTH-2010-single-stage grant 261504 EDENext. This paper is catalogued by the EDENext Steering Committee as EDENext032 (http://www.edenext. eu). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding received for this study

Schmallenberg virus experimental infection of sheep

International audienceSince late 2011, a novel orthobunyavirus, named Schmallenberg virus (SBV), has been implicated in many cases of severely malformed bovine and ovine offspring in Europe. In adult cattle, SBV is known to cause a mild transient disease; clinical signs include short febrile episodes, decreased milk production and diarrhoea for a few days. However, the knowledge about clinical signs and pathogenesis in adult sheep is limited. In the present study, adult sheep of European domestic breeds were inoculated with SBV either as cell culture grown virus or as virus with no history of passage in cell cultures. Various experimental set-ups were used. Sampling included blood collection at different time points during the experimental period and selected organ material at autopsy. Data from this study showed, that the RNAemic period in sheep was as short as reported for cattle; viral genome was detectable for about 3-5 days by real-time RT-PCR. In total, 13 out of 30 inoculated sheep became RNAemic, with the highest viral load in animals inoculated with virus from low cell culture passaged or the animal passaged material. Contact animals remained negative throughout the study. One RNAemic sheep showed diarrhoea for several days, but fever was not recorded in any of the animals. Antibodies were first detectable 10-14 days post inoculation. Viral RNA was detectable in spleen and lymph nodes up to day 44 post inoculation. In conclusion, as described for cattle, SBV-infection in adult sheep predominantly results in subclinical infection, transient RNAemia and a specific antibody response. Maintenance of viral RNA in the lymphoreticular system is observed for an extended period

Separated children seeking asylum in Ireland.

This report updates the first report of the Irish Refugee Council published in 1999, entitled Separated children seeking asylum in Ireland: A report on legal and social conditions. At the time of the publication of that report, there were 32 separated children seeking asylum in Ireland. The number of separated children seeking asylum in Ireland has increased markedly. By March 2003, the number of separated children, entering Ireland and referred to the North Eastern Area Health Board was 2,7172. Nearly half, or 1,113 children, were reunited with family members already in Ireland. 1,316 separated children, under the care of the Health Boards, have made applications for asylum under the 1951 Geneva Convention on the Status of Refugees. Neither the Government nor non-statutory agencies anticipated this increase in the numbers of separated minors arriving in Ireland. Therefore administrative procedures and care services have had to be responsive to emergent needs rather than having developed through advance planning. This report aims to examine policy and practice with respect to the legal and social conditions of separated children in Ireland, in light of the Separated Children in Europe Programme’s (SCEP)3 ‘Statement of Good Practice’ (SGP). The Irish Refugee Council, a member of the Separated Children in Europe Programme, commissioned the report

Etude de l'impact et choix de l'enrichissement du milieu sur l'élevage de lignées de souris transgéniques exempts d'organismes pathogènes spécifiques (EOPS) et opportunistes

National audienceFollowing changes in European animal testing regulations, animal welfare has taken an important place in animal testing. These changes have also impacted the breeding conditions of laboratory animals, particularly for mice. These conditions for breeding laboratory animals are also based on the 3Rs rule (Reduce, Replace and Refine). In this last R of refinement, the improvement of animal welfare in breeding conditions requires the implementation of enrichments adapted to the mouse line. This study therefore consisted in observations to compare different means of environmental enrichment on seven specific organism pathogen free (SOPF) mouse lines at different physiological stages and different housing conditions. The mice, regardless of age and with the same genetic background C57Bl/6, were grouped into six lots and three types of accommodation. For three consecutive weeks, daily observations were made on the use of fortification, such as igloo, Kraft curls and absorbent paper. A notation of the observations was therefore made based on the aggressiveness of the mice, the use of enrichment and the shape of the nest. Slight variations in the use of enrichment and mouse behaviour were observed between weeks, with improvement over time. All the enrichments were therefore used by the different mouse lines and increasingly over time, such as improving the shape of the nest after three weeks. The most commonly enrichment used is the absorbent paper sheet, followed by Kraft curl. These observations also show that enrichment is a dependent "lineage" and depends on the age and sex of the mice. In conclusion, mice showed an increased interest in the use of appropriate enrichments. This refinement work has therefore made it possible to define, for each SOPF mouse line, the type of enrichment of the environment most adapted to the conditions of mouse breeding and their wellbeing. These observations therefore made it possible to respond as effectively as possible to the regulations in force.Suite aux changements de la réglementation en expérimentation animale européenne, le bien-être animal a pris une place importante dans l’expérimentation animale. Ces changements ont aussi impacté les conditions d’élevages des animaux de laboratoire, en particulier celui des souris. Ces conditions d’élevage des animaux de laboratoire reposent également sur la règle des 3Rs (Réduire, Remplacer et Raffiner). Dans ce dernier R du raffinement, l’amélioration du bien-être animal en condition d’élevage passe par la mise en place d’enrichissements adaptés à la lignée de souris. Cette étude a donc consisté à réaliser des observations afin de comparer différents moyens d'enrichissement du milieu sur sept lignées de souris EOPS à différents stades physiologiques et différentes conditions d'hébergement. Les souris, sans distinction d’âge et avec le même fond génétique C57Bl/6, ont été groupées en six lots et dans trois types d’hébergement. Durant trois semaines consécutives, des observations journalières ont été faites sur l’utilisation des enrichissements utilisés, tels que l’igloo, les frisures kraft et la feuille de papier absorbant. Une notation des observations a été donc effectuée, basée sur l’agressivité des souris, l’utilisation de l’enrichissement et la forme du nid. Des variations légères d’utilisation des enrichissements et du comportement des souris ont été observées entre les semaines, avec une amélioration au fil du temps. L’ensemble des enrichissements ont donc été utilisés par les différents lignées de souris et de plus en plus au fil du temps, comme par exemple l’amélioration de la forme du nid après trois semaines. L’enrichissement le plus utilisé est la feuille de papier absorbant, suivi par la frisure kraft. Ces observations montrent également que l’enrichissement est « lignée » dépendante et fonction de l’âge et du sexe des souris. En conclusion, les souris ont montré un intérêt accru pour l’utilisation d’enrichissements adaptés. Ce travail de raffinement a donc permis de définir, pour chaque lignée de souris EOPS, le type d’enrichissement du milieu le plus adapté aux conditions d’élevage des souris et de leur bienêtre. Ces observations ont donc permis de répondre au mieux à la réglementation en vigueur

Nouvelle stratégie de modulation par les stérols de la résistance aux antihelminthiques médiée par les P-glycoprotéines chez Haemonchus contortus

National audienc

Cycle de vie de lignée murine C3HeB/FeJ exempts d'organismes pathogènes spécifiques (EOPS) : Modèle d'excellence pour l'étude de la tuberculose bovine

National audienc

Kinetic particles : from human pose estimation to an immersive and interactive piece of art questionning thought-movement relationships.

International audienceFigure 1: Preview of the proposed demonstration in use. On the right image, the "Particules" scenario illustrates how the human body mouvement is involved in the piece of art. On the left image, another scenario illustrates the immersive ability of the proposed installation

Effects of cholesterol content on activity of P-glycoproteins and membrane physical state, and consequences for anthelmintic resistance in the nematode Haemonchus contortus

International audienceEukaryote plasma membranes protect cells from chemical attack. Xenobiotics, taken up through passive diffusion, accumulate in the membranes, where they are captured by transporters, among which P-glycoproteins (Pgps). In nematodes such as Haemonchus contortus, eggshells and cuticles provide additional protective barriers against xenobiotics. Little is known about the role of these structures in the transport of chemical molecules. Pgps, members of the ABC transporter family, are present in eggshells and cuticles. Changes in the activity of these proteins have also been correlated with alterations in lipids, such as cholesterol content, in eggshells. However, the cellular mechanisms underlying these effects remain unclear. We show here that an experimental decrease in the cholesterol content of eggshells of Haemonchus contortus, with Methyl-beta-CycloDextrin (MβCD), results in an increase in membrane fluidity, favouring Pgp activity and leading to an increase in resistance to anthelmintics. This effect is modulated by the initial degree of anthelminthic resistance of the eggs. These results suggest that eggshell fluidity plays a major role in the modulation of Pgp activity. They confirm that Pgp activity is highly influenced by the local microenvironment, in particular sterols, as observed in some vertebrate models. Thus, eggshell barriers could play an active role in the transport of xenobiotics

In ovo administration of a phage cocktail partially prevents colibacillosis in chicks

ABSTRACT: Avian pathogenic Escherichia coli (APEC) causes colibacillosis, the main bacterial disease in poultry leading to significant economic losses worldwide. Antibiotic treatments favor the emergence of multidrug-resistant bacteria, and preventive measures are insufficient to control the disease. There is increasing interest in using the potential of bacteriophages, not only for phage therapy but also for prevention and biocontrol. This study aimed to evaluate the efficacy of a phage cocktail administered in ovo to prevent avian colibacillosis in chicks. When 4 different phages (REC, ESCO3, ESCO47, and ESCO58), stable under avian physiological conditions, were combined and inoculated at 17 embryogenic days (ED), they were transmitted to the newly hatched chicks. In a second trial, the 4-phage cocktail was inoculated into the allantoic fluid at ED16 and after hatch 1-day-old chicks were challenged with the O2 APEC strain BEN4358 inoculated subcutaneously. Two phages (REC and ESCO3) were still detected in the ceca of surviving chicks at the end of the experiment (7-days postinfection). Chicks that received the phages in ovo did not develop colibacillosis lesions and showed a significant decrease in intestinal BEN4358 load (8.00 × 107 CFU/g) compared to the challenged chicks (4.52 × 108 CFU/g). The majority of the reisolated bacteria from the ceca of surviving chicks had developed full resistance to ESCO3 phage, and only 3 were resistant to REC phage. The partially or complete resistance of REC phage induced a considerable cost to bacterial virulence. Here, we showed that phages inoculated in ovo can partially prevent colibacillosis in 1-wk-old chicks. The reduction in the APEC load in the gut and the decreased virulence of some resistant isolates could also contribute to control the disease

Étude de la toxicité tissulaire du paracétamol et mesure télémétrique de la variation de température lors d'une toxoplasmose chez la souris

National audienc