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usc The glucose portal sensor informs the brain of changes in glucose inflow through vagal afferents that require an activated glucagon-like peptide 1 receptor (GLP-1r). The GLP-1 system is known to be impaired in insulin-resistant conditions, and we sought to understand the consequences of GLP-1 resistance on glucose portal signaling. GLP-1–dependent portal glucose signaling was identified, in vivo, using a novel 68Ga-labeled GLP-1r positron-emitting probe that supplied a quantitative in situ tridimensional representation of the portal sensor with specific reference to the receptor density expressed in binding potential units. It also served as a map for single-neuron electrophysiology driven by an image-based abdominal navigation. We determined that in insulin-resistant animals, portal vagal afferents failed to inhibit their spiking activity during glucose infusion, a GLP-1r–dependent function. This reflected a reduction in portal GLP-1r binding potential, particularly between the splenic vein and the entrance of the liver. We propose that insulin resistance, through a reduction in GLP-1r density, leads to functional portal desensitization with a consequent suppression of vagal sensitivity to portal glucose. Refereed/Peer-reviewed

Our aim in this study was to investigate whether the behaviors of dairy cows on pasture, predicted with accelerometer data and combined with GPS data, can be used to better understand the relationship between behaviors and pasture characteristics. During spring 2018, 26 Holstein cows were equipped with a 3D-accelerometer and a GPS sensor fixed on a neck-collar for five days. The cows grazed alternatively in permanent and in temporary grasslands. The structural elements, soil moisture, slope and botanical characteristics were identified. Behaviors were predicted every 10 s from the accelerometer data and combined with the GPS data. The time-budgets expressed in each characterized zone of 8 m &times, 8 m were calculated. The relation between the time-budgets and pasture characteristics was explored with a linear mixed model. In the permanent grassland, dairy cows spent more time under a tree to ruminate (p &lt, 0.001) and to rest (p &lt, 0.001) and more time to graze in areas with Holcus lanatus (p &lt, 0.001). In the temporary grassland, behavior was influenced by the external environment (presence of other animals on the farm, p &lt, 0.05). Thus, this methodology seems relevant to better understand the relationship between the behaviors of dairy cows and grazing conditions to develop precision grazing.

International audience; La transition agroécologique initiée depuis les années 1990 vise à développer de nouveaux systèmes d'élevage qui optimisent la productivité tout en améliorant la santé des animaux et en diminuant les impacts environnementaux. Dans le cas particulier de l'élevage de bovins laitiers, la valorisation des prairies par le pâturage devrait permettre de répondre à plusieurs piliers de l'agroéocologie. Cette pratique est néanmoins complexe à mettre en oeuvre et une gestion inadaptée peut compromettre les bénéfices attendus (valorisation de l'herbe non optimale, stress des animaux sur les prairies, etc.). Dans le cadre de l'élevage de précision, des outils se développent pour améliorer les performances des exploitations mais ceux à destination du pâturage restent marginaux et de plus-value discutable. A ce propos, le comportement et la position des vaches laitières devraient servir de support au développement de nouveaux outils puisqu'ils sont des indicateurs potentiels de l'état de la ressource sur la parcelle, de la santé et du bien-être des animaux. Le comportement et la position peuvent être remontés automatiquement à partir d'accéléromètres et GPS embarqués sur les animaux, à condition de mettre en oeuvre des techniques d'analyse adaptées. Notre étude propose une méthodologie permettant de remonter automatiquement les principaux comportements des vaches laitières au pâturage à partir d'accéléromètres et à évaluer son potentiel pour les applications envisagées. La méthodologie développée s'appuie sur des techniques de traitement du signal non explorées en reconnaissance de comportements de ruminants, associées à une combinaison d'algorithmes qui met en jeu la complémentarité entre des méthodes de Machine Learning et des modèles probabilistes. Elle garantit une prédiction fiable pour un large spectre de comportements des vaches laitières au pâturage (pourcentage de bon classement : 98 % ; Kappa de Cohen : 0.96). La méthodologie, couplée avec des données de position des animaux dans la prairie, devrait permettre d'améliorer les performances, la santé et le bien-être des vaches laitières au pâturage, de mieux valoriser les intrants de la fertilisation ou encore de remonter des informations objectives sur les pratiques de production, constituant ainsi un levier potentiel dans la transition agroécologique.

Our objective was to measure the efficacy of ivermectin (IVM) and benzimidazoles (BZ, i.e. fenbendazole and albendazole) in 15 cattle farms in western France and southern Italy. A total of 11 groups were treated with IVM and 11 with BZ. Efficacy was assessed by calculating the percentage of faecal egg count reduction (%FECR) using the pre- and post-treatment arithmetic means. Anthelmintic resistance was considered to be present when the %FECR was

International audience; Monitoring livestock behaviour can be a useful way to improve farm animal management and to detect individual health events. The use of automated systems that predict several daily behaviours from accelerometer data is growing and studies have often focused on the comparison of datamining classification methods. However, few studies have attempted to evaluate the effect of the step preceding the classification, namely accelerometer signal pre-processing. This study aimed to evaluate the effect of several pre-processing methods on the prediction of dairy cows behaviour from accelerometer data. Ten Holstein cows equipped with a three-dimensional accelerometer fixed on a neck collar were simultaneously observed by two observers. Observed behaviours were predicted with decision tree using pre-processed accelerometer data as inputs. Different procedures were evaluated for each of these following pre-processing steps: signal filtering, signal segmentation and feature calculation. For signal filtering, low-pass filters and high-pass filters were considered. For signal segmentation, various window sizes and percentages of overlap between windows were implemented. Sixty-one features were computed. This resulted in 150 different combinations of pre-processing steps. For each combination a decision tree model predicting the observed behaviours was trained. The performance of each model to predict the observed behaviours was compared based on accuracy and F-score measures. The relative importance of each pre-processing configuration on the performance of prediction was evaluated with a linear regression model. The best configurations led to an accuracy of 0.95 and a F-score of 0.96 against 0.76 and 0.65 respectively with the worse combinations. The best combinations included a window size of 20 s and 30 s, with an overlap of 90% and no high-pass filter. High-pass filter had the most significant effect on the classification (P

Background Faecal egg counts (FEC) and the FEC reduction test (FECRT) for assessing gastrointestinal nematode (GIN) infection and efficacy of anthelmintics are rarely carried out on ruminant farms because of the cost of individual analyses. The use of pooled faecal samples is a promising method to reduce time and costs, but few studies are available for cattle, especially on the evaluation of different pool sizes and FECRT application. Methods A study was conducted to assess FEC strategies based on pooled faecal samples using different pool sizes and to evaluate the pen-side use of a portable FEC-kit for the assessment of FEC on cattle farms. A total of 19 farms representing 29 groups of cattle were investigated in Italy and France. On each farm, individual faecal samples from heifers were collected before (D0) and two weeks after (D14) anthelmintic treatment with ivermectin or benzimidazoles. FEC were determined individually and as pooled samples using the Mini-FLOTAC technique. Four different pool sizes were used: 5 individual samples, 10 individual samples, global and global on-farm. Correlations and agreements between individual and pooled results were estimated with Spearman’s correlation coefficient and Lin’s concordance correlation coefficients, respectively. Results High correlation and agreement coefficients were found between the mean of individual FEC and the mean of FEC of the different pool sizes when considering all FEC obtained at D0 and D14. However, these parameters were lower for FECR calculation due to a poorer estimate of FEC at D14 from the faecal pools. When using FEC from pooled samples only at D0, higher correlation and agreement coefficients were found between FECR data, the better results being obtained with pools of 5 samples. Interestingly, FEC obtained on pooled samples by the portable FEC-kit on-farm showed high correlation and agreement with FEC obtained on individual samples in the laboratory. This field approach has to be validated on a larger scale to assess its feasibility and reliability. Conclusions The present study highlights that the pooling strategy and the use of portable FEC-kits on-farm are rapid and cost-effective procedures for the assessment of GIN egg excretion and can be used cautiously for FECR calculation following the administration of anthelmintics in cattle.

The functional roles of the Caudate nucleus (Cd) are well known. Selective Cd lesions can be found in neurological disorders. However, little is known about the dynamics of the behavioral changes during progressive Cd ablation. Current stereotactic radiosurgery technologies allow the progressive ablation of a brain region with limited adverse effects in surrounding normal tissues. This could be of high interest for the study of the modified behavioral functions in relation with the degree of impairment of the brain structures. Using hypofractionated stereotactic radiotherapy combined with synchrotron microbeam radiation, we investigated, during one year after irradiation, the effects of unilateral radio-ablation of the right Cd on the behavior of Yucatan minipigs. The right Cd was irradiated to a minimal dose of 35.5 Gy delivered in three fractions. MRI-based morphological brain integrity and behavioral functions, i.e. locomotion, motivation/hedonism were assessed. We detected a progressive radio-necrosis leading to a quasi-total ablation one year after irradiation, with an additional alteration of surrounding areas. Transitory changes in the motivation/hedonism were firstly detected, then on locomotion, suggesting the influence of different compensatory mechanisms depending on the functions related to Cd and possibly some surrounding areas. We concluded that early behavioral changes related to eating functions are relevant markers for the early detection of ongoing lesions occurring in Cd-related neurological disorders.

In dairy cows, the milk production (MP) response to anthelmintic treatment (AT) is variable, and the decision to treat still depends on how much risk averse farmers or vets are. The objective of this study was to develop a stepwise decision making strategy based on nested criteria associated with an increasing probability of MP response. A randomized controlled trial was conducted at housing in 123 grazing dairy herds (injectable eprinomectin). Monthly individual test-day milk yields were obtained. Linear mixed models were used to assess the effect of AT on MP. In a first step, all herds were included in the analysis. The criterion associated with the highest MP response was identified. In a second step, only herds meeting the first criterion were included in order to identify the criterion associated with the highest MP response in this subset. This was repeated a third time on herds meeting the first 2 criteria. When all the herds were taken into account, the effect of AT was significant but low (+0.3 kg/cow/day). The first discriminating criterion (step 1) was identified as the % of grazed grass in the diet (no MP gain in low-pasturing herds versus +1 kg/cow/day in moderate/high-pasturing herds). Among moderate/high-pasturing herds, the second discriminating criterion (step 2) was the TEC (+0.6 kg/cow/day in high-TEC herds versus +1.4 kg/cow/day in low-TEC herds). Finally, among moderate/high-pasturing AND low-TEC herds, the third discriminating criteria (step 3) was the bulk tank milk Ostertagia ODR (+0.2 versus +1.8 kg/cow/day when ODR < 0.9 and ≥ 0.9, respectively). The 3 criteria identified, when applied sequentially, are associated with increasing expected MP gains and are useful for farmers and vets with different attitudes regarding risk.

SUMMARYHeat shock protein 90 (HSP90) is a key component of the molecular chaperone complex essential for activating many signalling proteins involved in the development and progression of pathogenic cellular transformation. AHsp90gene (BQHsp90) was cloned and characterized fromBabesiasp. BQ1 (Lintan), an ovineBabesiaisolate belonging toBabesia motasi-like group, by screening a cDNA expression library and performing rapid amplification of cDNA ends. The full-length cDNA ofBQHsp90is 2399 bp with an open reading frame of 2154 bp encoding a predicted 83 kDa polypeptide with 717 amino acid residues. It shows significant homology and similar structural characteristics toHsp90of other apicomplex organisms. Phylogenetic analysis, based on the HSP90 amino acid sequences, showed that theBabesiagenus is clearly separated from other apicomplexa genera. Five Chinese ovineBabesiaisolates were divided into 2 phylogenetic clusters, namelyBabesiasp. Xinjiang (previously designated a new species) cluster andB. motasi-like cluster which could be further divided into 2 subclusters (Babesiasp. BQ1 (Lintan)/Babesiasp. Tianzhu andBabesiasp. BQ1 (Ningxian)/Babesiasp. Hebei). Finally, the antigenicity of rBQHSP90 protein from prokaryotic expression was also evaluated using western blot and enzyme-linked immunosorbent assay (ELISA).

International audience; The suitability of a single mid-season targeted selective treatment (TST) for gastrointestinal nematodes control, based on flexible average daily weight gain (ADWG) thresholds, was investigated in 23 groups of first grazing season calves. In each group, animals were weighed three times: before turnout, at mid-season and at housing. Just after the first weighing, each group was divided in two homogenous sub-groups in terms of age, breed and weight, and randomly allocated to one of two sub-groups intented for two different mid-season anthelmintic treatment strategies: (1) a treatment of all calves composing the sub-group (whole-group treatment (WT)) or (2) a targeted selective weight gain-based treatment (TST) of the animals showing an individual pre-treatment ADWG inferior to the mean pre-treatment ADWG of the corresponding WT sub-group. Anthelmintic treatment (levamisole 7.5 mg/kg BW) was performed 3 to 4 months after turnout. At housing, two parasitological parameters (the anti-Ostertagia ostertagi antibody level-Ostertagia optical density ratio (ODR) and the pepsinogen level) and a clinical parameter (the breech soiling score) were assessed at individual level in each group. Then, the high exposed groups to gastrointestinal nematode (GIN) were defined as groups for which untreated animals exhibited a mean Ostertagia ODR ⩾ 0.7 and among these groups, the ones characterized by high abomasal damage due to Ostertagia for which untreated animals exhibited a mean pepsinogen level ⩾ 2.5 U Tyr were also identified. Among TST sub-groups, the treatment ADWG thresholds varied from 338 to 941 g/day and the percentage of treated animals from 28% to 75%. Pre- and post-treatment ADWG as well as parasitological and clinical parameters measured at housing were similar between TST and WT sub-groups including the 17 high exposed groups to GIN. Within these 17 groups, the treatment allowed to significantly improve post-treatment ADWG compared with untreated animals. In the six high exposed groups showing mean pepsinogen level ⩾ 2.5 U Tyr, the average effect of treatment on post-treatment ADWG was the highest and estimated up to 14 kg after a grazing duration of 4 months. In contrast, in six other groups showing mean Ostertagia ODR < 0.7 in untreated animals, no effect of treatment was seen suggesting an absence of production losses related to a low level of GIN infection. This study highlighted the suitability of a convenient mid-season TST strategy for first grazing season calves, based on the use of flexible thresholds of ADWG, allowing similar growth compared with a whole-group treatment while keeping a GIN population in refugia.

Chez les ruminants élevés au pâturage, les strongles gastro-intestinaux (SGI) peuvent induire des pertes de production, voire des atteintes cliniques chez les animaux non immuns. Le contrôle de l’infestation repose essentiellement sur les traitements anthelminthiques (AH) administrés fréquemment sans évaluation préalable de la réalité du risque parasitaire. Cette synthèse vise tout d’abord à exposer les principaux risques associés à ce recours insuffisamment raisonné aux AH : apparition de populations de parasites résistants aux AH, écotoxicité pour la microfaune prairiale dégradant les fèces, et installation retardée de l’immunité anti-strongles (notamment chez les bovins). Les stratégies de traitement ciblé-sélectif devraient permettre de maîtriser ces risques tout en prévenant les atteintes cliniques et sécurisant les performances des animaux. Il s’agit de rationaliser les traitements AH en ciblant les troupeaux ou les lots et les périodes à risque, et en sélectionnant les individus les plus parasités ou « souffrant » le plus du parasitisme. Cette synthèse vise donc ensuite à décrire les outils et les indicateurs étudiés pour mettre en œuvre de telles stratégies chez les ruminants. Il s’agit d’indicateurs zootechniques (gain moyen quotidien, parité, niveau de production…), cliniques (FAMACHA©, index de diarrhée…), parasitologiques (coproscopie, niveau d’anticorps anti-SGI…), ou d’indicateurs de conduite (modalité de pâturage), et aussi d’outils informatiques (modélisation du recyclage parasitaire). Leur fiabilité et leur opérationnalité sont variables. La mise en place de telles stratégies nécessitera de dépasser les freins à l’acceptation de ces nouvelles pratiques tant au niveau des éleveurs que des vétérinaires prescripteurs. Cet usage raisonné des AH assurerait une meilleure durabilité du contrôle de l’infestation par les SGI.

A two-year study was carried out to assess the feasibility of a targeted selective treatment to control gastrointestinal nematodes (GIN) in 24 groups of first grazing season (FGS) cattle. A two-step procedure aiming at defining exposure risk at group level and at identifying the most infected individuals within groups through measurement of the average daily weight gain (ADWG) at housing was used. The first step was to define retrospectively, by grazing management practices (GMP) indicators, two levels of groups’ exposure to GIN determined by anti O. ostertagi antibody ODR level (cut-off 0.7). For the low level of exposure, no relationship between parasitological parameters and heifer growth was seen, whereas for the high level ADWG was negatively correlated with increasing Ostertagia ODR values. The best classification was obtained with an expert system modelling the number of Ostertagia L3 generations on plots. GMP input for the expert system included standard data (turnout/housing data and supplementary feeding amount) combined with paddock rotation planning and monthly temperatures. The threshold of 3 successive generations of L3 or more on plots allowed identifying the groups according to low or high infection exposure level, except two groups that were misidentified as being highly exposed. In the second step, individual ADWG was found to be negatively associated with Ostertagia ODR in heifers from groups classified as highly exposed (≥3 generations of L3). In these groups, sensitivity and specificity of ADWG thresholds were calculated for several individual Ostertagia ODR thresholds. The best compromise between sensitivity (i.e., correctly treating the heifers that need to be treated) and specificity (i.e., not treating animals that should not be treated) was equivalent respectively to 76% and 56% (AUC ≈ 0.7) and was reached using an end-season ADWG threshold of 683 g/day to detect animals exhibiting an Ostertagia ODR cut-off at 0.93. Other ADWG thresholds were proposed taking into account the farmers’ or the veterinarians’ objectives: either maximizing the production through both an increase of the ADWG threshold and the sensitivity or keeping a significant nematode population in refugia with a corresponding limitation of anthelmintic treatments through a decrease of ADWG threshold and an increase of the specificity. Finally, a targeted selective treatment for FGS cattle based on GMP and flexible ADWG thresholds seems feasible at housing without laboratory analysis, accepting that some resilient animals with high Ostertagia ODR will not be treated due to their ability to perform under parasitic challenge.

Targeted-selective treatments against gastrointestinal nematode (GIN) in adult dairy cows require the identification of “cows to treat”, i.e. cows whose milk production (MP) would increase after treatment. This study aimed at quantifying the ability of multi-indicator profiles to identify such cows. A randomized controlled clinical trial was conducted at housing in 25 French pasturing dairy herds. In each herd, treated cows received fenbendazole orally, control cows remained untreated. Daily MP was recorded and the MP variation between the pre- and post-visit periods was calculated (ΔMP) for each cow. ΔMP was modelled with control cows data (n = 412) (piecewise linear mixed model). Estimated parameters were applied to treated cows data (n = 414) to predict the expected ΔMP in treated cows if they had not been treated. Treated cows with an observed ΔMP (with treatment) higher than the expected ΔMP (without treatment) were labelled as “cows to treat”. Herds where at least 50% of the young cows were “cows to treat” were qualified as “herds to target”. To characterize such cows and herds, the available candidate indicators were (i) at the cow-level: parity, stage of lactation and production level, faecal egg count (FEC), serum pepsinogen level and anti-Ostertagia antibody level (expressed as ODR); (ii) at the herd-level: bulk tank milk (BTM) Ostertagia ODR, Time of Effective Contact (TEC, in months) with GIN infective larvae before the first calving, and percentage of positive FEC. These indicators were tested one-by-one or in combination to assess their ability to characterize “herds to target” and “cows to treat” (Chi-square tests). 115 out of 414 treated cows (27.8%) were considered as “cows to treat”, and 9 out of 22 herds were qualified as “herds to target”. The indicators retained to profile such cows and herds were the parity, the production level, the BTM Ostertagia ODR and the TEC. Multi-indicator profiles were much more specific than single indicator profiles, induced lower treatment rates, thereby minimizing the selection pressure on parasite populations. Particularly, to target a herd, the specificity was better with the profile “high BTM Ostertagia ODR and low-TEC” than with the BTM ODR value taken into account alone. The targeted-selective treatment of “young cows, belonging to herds with a high BTM ODR at housing and a low TEC” appeared as a pertinent solution, enabling a global approach for the control of GIN infection in which GIN control in heifers is connected to GIN control in adult cows.

A carbohydrate larval surface antigen (CarLA) present on infective larvae of all trichostrongylid nematodes is a target antigen for host immunoglobulins (Ig). Levels of anti-CarLA salivary IgA antibody (CarLA-IgA) have been shown to be correlated to the level of protective immunity to GIN in sheep and deer but no information is available in cattle. The first objective of this study was to assess the pattern of CarLA-IgA response in 7 groups (G1-G7) of first grazing season cattle (FGSC) naturally infected with gastrointestinal nematodes. The second objective was to assess the phenotypic correlations between CarLA-IgA level, 3 parasitological indicators (faecal egg count-FEC, pepsinogen level, serum anti- O. ostertagi IgG antibody level- Ostertagia IgG), a clinical indicator (diarrhea score) and average daily weight gain (ADWG). Overall, CarLA-IgA response gradually increased over grazing season and showed large variations in speed and magnitude both between and within groups. Based on the mean group CarLA-IgA response pattern, the 7 groups could be allocated to 3 different classes: (i) ‘Late High’ class characterized by a high response at housing (G1 and G2); (ii) ‘Low’ class with a low response over time (G3, G4 and G5); and (iii) ‘Early’ class with an high initial then stable response (G6 and G7). This classification was consistent with the grazing management practices. In the ‘Late High’ class, the mean CarLA-IgA at housing was 6.05 units/mL and negatively correlated with FEC while no correlation was seen with the other indicators nor ADWG. In the ‘Low’ class, CarLA response at housing was low (1.95 units/mL) and mainly positively correlated with Ostertagia IgG. In the ‘Early’ class, mean CarLA-IgA ranged from 1.32 to 1.86 units/mL during the grazing season and positive correlations were seen with parasitological and clinical indicators. These results suggest that, according to the intensity of larval challenge occurring during the first grazing season, CarLA-IgA response in cattle could be either an indicator of the early manifestation of immunity (FEC decreases) or the reflection of exposure to GIN.

To investigate future tools for targeted selective treatment against gastrointestinal nematodes (GIN) in adult dairy cows, we evaluated herd and individual cow factors associated with the post-treatment milk production (MP) response over time. A field trial involving 20 pasturing dairy herds in Western France was conducted in autumn 2010 and autumn 2011. In each herd, lactating cows were randomly allocated to a treatment group (fenbendazole) (623 cows), or a control group (631 cows). Daily cow MP was recorded from 2 weeks before until 10 to 14 weeks after treatment. Individual serum anti-Ostertagia antibody levels (expressed as ODR), pepsinogen levels, faecal egg count (FEC), and bulk tank milk ODR were measured at the time of treatment. Moreover, in each herd, information regarding heifers' grazing and treatment history was collected to assess the Time of Effective Contact (TEC, expressed in months) with GIN infective larvae before the first calving. TEC was expected to reflect the development of immunity against GIN, and TEC=8 months was a cautious threshold over which the resistance to re-infection was expected to be established. Daily MP averaged by week was analyzed using linear mixed models with three nested random effects (cow within herd and herd within year). The overall treatment effect was significant but slight (maximum=+0.85kg/d on week 6 after treatment), and the evolution of treated cows' MP differed significantly according to several factors. At the herd level, cows from low-TEC herds responded better than cows from high-TEC (≥8 months) herds; cows from herds in which the percentage of positive FEC was >22.6% (median value) responded better than those from herds where it was lower. At the individual cow level, primiparous cows, cows with days in milk (DIM) < or = 100 at the time of treatment, and cows with low individual ODR (< or = 0.38) responded better than multiparous cows, cows with DIM>100, and cows with higher ODR, respectively. These results highlight the variability of the treatment response, suggesting that whole herd anthelmintic treatment are not always appropriate, and propose promising key criteria for targeted selective treatment for GIN in dairy cows. Particularly, the TEC is an original criterion which lends support for a simultaneous on-farm qualitative analysis of grazing management factors.

Les décisions de gestion de la santé animale correspondent à un large éventail de situations et de problèmes. Illustrant ce constat, sept maladies majeures des troupeaux bovins laitiers sont examinées pour identifier les facteurs les plus courants limitant l’efficacité des plans de maîtrise ainsi que les perspectives d’amélioration de la maîtrise sur le terrain. Pour les infections intra-mammaires, la recherche vise à la mise au point de vaccins multivalents, le ciblage des vaches à traiter par les antibactériens, la méthodologie des interventions en ferme, et l’augmentation de la résistance innée par la sélection génomique. Pour les strongyloses gastro-intestinales, les recherches prioritaires s’orientent aussi vers les stratégies de traitement anthelminthique raisonné et ciblé, la voie génétique semblant moins prioritaire que chez les petits ruminants. La maîtrise de la maladie de Mortellaro, affection de l’appareil locomoteur, ne pourra plus recourir aux désinfectants classiquement utilisés dans les pédiluves et des approches alternatives sont nécessaires. La maîtrise de la fièvre Q est à rechercher par la vaccination de l’ensemble du troupeau sur plusieurs années et l’hygiène de la parturition. La paratuberculose pourrait à terme être maîtrisée par la sélection génomique, en raison de l’absence de traitement et de vaccin efficaces et de l’existence de bases génétiques de résistance/résilience prometteuses. La maîtrise de l’infection par le virus BVDV semble pouvoir être atteinte par des mesures sanitaires combinées ou non avec la vaccination. La quasi-éradication des sérotypes exotiques du virus de la fièvre catarrhale ovine pourrait être obtenue par la surveillance ciblée et la vaccination massive et rapide. Les spécificités de l’étiologie, de l’épidémiologie et des moyens de maîtrise des maladies étudiées n’autorisent guère de conclusions génériques, Decisions in animal health management depend on a large variety of situations and problems. To illustrate this, seven major diseases of dairy herds were analysed to identify the main limiting factors for the effectiveness of the current control schemes and the perspectives toward better control in the field. Regarding intramammary infections, research directions focus on the development of multivalent vaccines, tools to better select cows to be treated with antibiotics, on-farm intervention methodology and the enhancement of animal resistance via a contribution of genome-wide selection techniques. For gastro-intestinal strongyloses, priority was also given to rational and selective anthelmintic treatments, genetic improvement of innate resistance seeming less a priority than for small ruminants. The control of Mortellaro disease, a locomotor disorder, should receive attention to develop alternatives because of the forecasted ban of the principal disinfectants used for footbaths. Q fever control can be reached by prolonged vaccination of the whole herd and adequate management of parturition hygiene. Johne disease is probably a good candidate disease for genomic selection, especially given the absence of treatment and very effective vaccine and the presence of a quite promising background of resistance/resilience. Infection by BVDV seems to be controllable by only sanitary measures, associated or not with a vaccination scheme. Eradication of exotic serotypes of BTV can be reached by targeted surveillance and quick and massive vaccination. Specificities in etiology, epidemiology and control techniques of the diseases under study do not quite allow drawing generic conclusions.

The objective of our study was to explain the variability of average daily weight gain (ADWG) due to gastrointestinal nematode (GIN) infection for 291 non treated first grazing season (FGS) heifers, from 12 independent groups in the western part of France, by combining parasitological and clinical indicators at individual level and grazing management indicators at group level. Parasitological indicators were faecal egg count (FEC), anti Ostertagia ostertagi antibody level (Ostertagia ODR), and pepsinogen level. Clinical indicators were diarrhea score (DISCO) and breech soiling score (BSS). At group level, grazing management practice (GMP), based on three variables (supplementation, month of turnout, grazing season duration), was clustered into three categories reflecting low, medium or high exposure (EXP) to GIN. Depending on the groups, turnout was from mid-March to early July and housing was from mid-October to late November, with a FGS duration ranging from 4 to 8.4 months. At turnout, the mean age of heifers was 8 months (range: 6–16 months) and they weighed between 175 and 268 kg. In each GMP category, FEC significantly decreased between the mid-season and the housing, while Ostertagia ODR and pepsinogen level increased gradually throughout the grazing season. In contrast, clinical indicators did not show any seasonal variation. In a multivariate linear model, 22% of the ADWG variability was significantly explained by two individual indicators (Ostertagia ODR: 12.6%, DISCO: 4.8%) and by the group indicator (GMP category: 4.8%). ADWG losses due to GIN exposure (Ostertagia ODR) were estimated up to 39 kg per heifer for the overall grazing season. For groups within the low EXP category the difference between animals with low (697 g/day) ADWG was explained by the clinical indicator DISCO. In contrast, for groups within the medium and high EXP categories this difference was explained by a parasitological indicator (Ostertagia ODR). This study highlighted the value of combining both grazing management (group level) and parasitological (individual level) indicators to assess the impact of GIN on ADWG of FGS heifers. As a result, this combination might allow a better discrimination of animals or groups that may be in need of treatment in a targeting selective treatment approach

Gastrointestinal nematodes (GIN) infection can impair milk production (MP) in dairy cows. To investigate whether MP would be optimized by spring targeted-selective anthelmintic treatment in grazing cows, we assessed (1) the effect on MP of an anthelmintic treatment applied 1.5 to 2 months after turn-out, and (2) herd and individual indicators associated with the post-treatment MP response. A randomized controlled clinical trial was conducted in 13 dairy farms (578 cows) in western France in spring 2012. In each herd, lactating cows of the treatment group received fenbendazole orally, control cows remained untreated. Daily cow MP was recorded from 2 weeks before until 15 weeks after treatment. Individual serum pepsinogen and anti-Ostertagia antibody levels (expressed as ODR), faecal egg count and bulk tank milk (BTM) Ostertagia ODR were measured at treatment time. Anthelmintic treatment applied during the previous housing period was recorded for each cow. In each herd, information regarding heifers’ grazing and anthelmintic treatment history was collected to assess the Time of Effective Contact (TEC, in months) with GIN infective larvae before the first calving. The effect of treatment on weekly MP averages and its relationships with herd and individual indicators were studied using linear mixed models with two nested random effects (cow within herd). Unexpectedly, spring treatment had a significant detrimental effect on MP (-0.92 kg/cow/day on average). This negative MP response was particularly marked in high producing cows, in cows not treated during the previous housing period or with high pepsinogen levels, and in cows from herds with a high TEC or a high BTM ODR. This post-treatment decrease in MP may be associated with immuno-inflammatory mechanisms. Until further studies can assess whether this unexpected result can be generalized, non-persistent treatment of immunized adult dairy cows against GIN should not be recommended in early grazing season.

In a region-wide serologic study carried out in 2004 on free-ranging hunted roe deer in various landscapes, we found that 58% of the animals (237 out of 406) were antibody positive for Babesia divergens antigen. Serologic and infection status was also analyzed for 327 roe deer live-trapped in two fenced forest areas over 5 yr (2004-08). For two consecutive years during this period, 92 and 94% of the deer in these closed populations were antibody-positive for B. divergens. Babesia spp. were isolated in autologous red blood cell culture for 131 of the trapped animals (40%). Molecular typing was done on 76 isolates with polymerase chain reaction (PCR)-restriction fragment length polymorphism methods targeted at the 18S ribosomal subunit gene (18 isolates) and the Bd37 gene coding for a merozoïte surface antigen implicated in a protective response (60 isolates). Results indicated continuous cocirculation of B. capreoli and B. venatorum in both forests and possible coinfection of animals with both species. No infection with B. divergens was detected. Fifteen isolates were confirmed to be B. capreoli by sequencing part of the 18S rRNA gene. Using PCR detection of the Bd37 gene, all nine isolates of B. venatorum in this study were negative, whereas the 15 confirmed and 50 putative B. capreoli isolates showed very variable restriction profiles, distinct from those known for Bd37 in B. divergens. Two isolates showed conflicting results, suggestive of mixed infection.

Les strongles gastro intestinaux (SGI) peuvent être responsables chez les génisses de première saison de pâturage (PSP) de retards de croissance. L’objectif de notre étude a été d’expliquer la variabilité du gain de poids (GMQ) de 291 génisses, non vermifugés, en PSP, à l’aide d’indicateurs individuels (parasitologiques et cliniques) et de groupe (niveau d’exposition aux SGI - EXP basé sur les pratiques de conduite de pâturage). 22 % de la variabilité du GMQ était significativement expliquée par deux indicateurs individuels (niveau d’anticorps anti O. ostertagi - RDO, score de diarrhée - SD) et par l’indicateur de groupe (EXP). Sur l’ensemble de la saison de pâture, les pertes de GMQ dues à l’exposition aux SGI (RDO) ont pu atteindre 39 kg par génisse. Seul dans les lots exposés significativement aux SGI la différence entre des animaux à faible (< 697g/jour) et fort (> 697 g/jour) GMQ a pu être expliquée par un indicateur lié au parasitisme (RDO). Cette étude a confirmé la possibilité de rationaliser les traitements en direction des animaux présentant des faibles GMQ. De plus, la prise en compte simultanée d’un indicateur d’exposition de groupe basé sur les pratiques de conduite de pâturage pourrait permettre une meilleure discrimination des animaux à traiter

Babesia divergens and Babesia capreoli are closely related species with distinct host ranges, a zoonotic feature being described only for B. divergens. The two species are 99.8% similar in the 18S rDNA gene sequence and indistinguishable by morphological or serological means, leading to confusion as to their species status. The phylogenetic relatedness between the two species, and the frequent involvement of surface components in serological cross-reactions led us to postulate that an ortholog of Bd37, the merozoite surface antigen described for B. divergens, could also exist in B. capreoli. We were able to amplify a single partial PCR product from B. capreoli genomic DNA using primers specific for the B. divergens merozoite surface protein coding gene Bd37, and sequencing confirmed the presence of a Bd37 ortholog in B. capreoli, named Bcp37/41. The full sequences of the Bcp37/41 genes and their intron-exon structures were obtained for two cloned lines of B. capreoli. They suggest functional homologies between Bd37 and Bcp37/41 such as their surface localization, their role in immune escape mechanism and in the initial non-specific attachment to the erythrocyte. Restriction fragment length polymorphism (RFLP) analysis of the amplicons and partial sequencing revealed an extreme polymorphism within B. capreoli, greater than the one observed for its ortholog Bd37. Such a marker could thus be useful in epidemiological as well as phylogenetic studies.

The entero-pancreatic (EP) neurons directly link the proximal duodenum to the pancreas and participate to the pre absorptive phase of postprandial insulin secretion. EP neurons may therefore play a critical role in the postprandial inhibition of hepatic gluconeogenesis mandatory for an adequate postprandial glucose tolerance and a good overall insulin sensitivity. To test this hypothesis, modified oral glucose tolerance tests (mOGTT) were performed every 2 months for 6 months in intact (n = 3) and EP denervated minipigs (n = 4). An euglycemic hyperinsulinemic clamp procedure (EHC) was performed at the end of the experiment to estimate insulin sensitivity. EP denervation was achieved by sectioning the connective tissue between the pancreas and the proximal duodenum. The mOGGT consisted in the standard daily ration plus 1.5 g of glucose per kg of body weight. Postprandial glycemia and insulinemia were not affected by the EP denervation (P = 0.86 and P = 0.46 for glycemia and insulinemia respectively). The insulinogenic index (ISI = AUCinsulin/AUCglucose) was not significantly different in IEP and XEP animals either (P = 0.13). The final EHC highlighted a tendency for XEP to be less insulin sensitive than IEP (P = 0.09). We concluded that EP neurons were not mandatory for an adequate postprandial glucose tolerance but might contribute to the overall insulin sensitivity in pigs.

The pathogenicity and morphology of a large Babesia species, Babesia sp. Xinjiang, are described here. The parasite has very low virulence for sheep, and caused no detectable clinical symptoms. Splenectomized sheep infected with the parasite showed mild fever and low parasitemia and would recover gradually. If splenectomized sheep were immuno-suppressed with dexamethasone, the parasitemia could reach 8.5%, and death occurred. A splenectomized calf could not be infected with the Babesia species. Paired parasites were the typical form of the Babesia species in erythrocytes and the average size of a pair of parasites was 2.42 (+/-0.35) microm x 1.06 (+/-0.22) microm. Merozoites were found in the gut, salivary gland, haemolymph, ovary and eggs of female Hyalomma anatolicum anatolicum engorged on sheep infected with the parasites. The results of experimental transmission showed that the larval, nymph and adult stages of H. a. anatolicum could transmit the Babesia species to sheep.

AlthoughBabesia divergensis the the principal confirmed zoonoticBabesia sp. in Europe, there are gaps in our knowledge of its biology and transmission by the tickIxodes ricinus. In order to reproduce the part of the parasite cycle that occurs in the vector, anin vitroanimal skin feeding technique on blood containingin vitrocultivatedB. divergenswas developed. Parasite DNA was detected in all samples of salivary glands of nymphs and adults that had fed on parasitized blood as larvae and nymphs, respectively, indicating acquisition as well as a transtadial persistence ofB. divergens. PCR performed on eggs and larvae produced by females that had fed on parasitized blood demonstrated the existence of a transovarial transmission of the parasite. GorgingB. divergensinfected larvae on non-infected gerbils showed persistance of the parasite over moulting into the resulting nymphs. These results indicate that the parasitic stages infective for the vector (i.e. the sexual stages) can be producedin vitro. To our knowledge, this is the first report of artificial feeding ofI. ricinusvia membrane as well asin vitrotransmission ofB. divergensto its vector. The opportunities offered by the use of such a transmission model of a pathogen byI. ricinusare discussed.

The aerodynamic characteristics of wind turbines are closely related to the geometry of their blade profiles. The innovation and the technological development of wind turbine blade profiles can be centred on two tendencies. The first is to improve the shape of the existing airfoils and the second is to design new shapes of airfoils in order to get some more ambitious aerodynamic characteristics and enhanced performance. The aim of this paper is to develop an accurate airfoil analysis lower order code, based on the singularities method, for wind turbine applications. The 2D incompressible potential flow model has been used. In the implementation of the singularities method, source–vortex distributions over the airfoil contour are used to compute the flow characteristics. The accuracy and the validity of the results have been tested using experimental data obtained from Wind Turbine Airfoil Catalogue “Riso National Laboratory, Roskilde, Denmark, August 2001” and have shown considerable agreement.

Humoral response of sheep to F. gigantica was compared with the well known humoral response to F hepatica, in order to explain the difference of susceptibiIity of sheep to these two parasites. In this work, a lesser susceptibility of sheep to F. gigantica than to F. hepatica infection was confirmed. Humoral response to F. hepatica infection is similar to that previously described by several authors. IgG level of F. gigantica infected sheep increased from week 2 post-infection (2WPI) and displayed a peak at 13WPI. F. gigantica excretory secretary products (FgESP) analyzed by SDS-PAGE showed at least 31 bonds from 12.0 to 127.6 kDa in FgESP. Western blot indicated that F. gigantica infected sheep sera recognized, in FgESP, at least 30 antigens from 7.8 to 119.2 kDa of which 12 motor bands recognized after OWPI. In RESP and FqESP, F. hepatica infected sheep serum reacted only with the lower molecular mass antigens, while F. gigantica infected sheep serum reacted with the lower and the higher moleculer mass antigens. These differences of antigenic recognition might be associated with the difference of susceptibility of sheep, Further investigation must be done to study the mechanism of resistance between the sheep infected with F. hepatica or F. gigantica., La réponse humorale du Mouton induite par F. gigantica a été comparée à celle induite par F. hepatica, bien connue, afin d'expliquer les différences de sensibilité du Mouton à ces deux parasites. Dans cette étude, la moindre sensibilité du Mouton à F. gigantica par rapport à F.hepatica a été confirmée. La réponse humorale à F. hepatica est similaire à celle décrite précédemment par de nombreux auteurs. La quantité d'IgG des moutons infestés par F. gigantica augmente dès la 2ème semaine après infestation (SPI2) et atteint un pic en SPI 13. L'analyse des produits d'excrétion-sécrétion de F. gigantica IPESFgj par SDSPAGE a révélé au moins 3 I bandes de 12.0 à 127.6 kDa. Les Western blot indiquent que les moutons infestés par F. gigantica reconnaissent dans les PESFg au moins 30 antigènes de 7.8 à 1 19.2 kDa dont 12 bandes majeures détectées après SPIO. Dans les deux PES, les sérums des moutons Infestés par F. hepatica réagissent uniquement avec les antigènes majeurs de bas poids moléculaires alors que ceux des moutons infestés par F. gigantica réagissent avec les antigènes majeurs de bas et de hauts poids moléculaires. Ces différences de reconnaissance antigénique pourraient être associées aux différences de sensibilité des moutons. D'autres investigations seraient nécessaires pour étudier les mécanismes de résistance des moutons infestés par F. hepatica ou par F. gigantica.

The vagus is involved in the cephalic phase of insulin secretion but its role in the meal absorption phase of insulin release remains to be defined. The aim of this study was therefore to evaluate the role of the vagus in the early and the late meal absorption phases of insulin secretion. In six pigs, venous insulin profiles were compared in intact animals, after ventral or dorsal vagal trunk section, and after section of both vagal trunks (truncal vagotomy). Since gastric emptying could be modified by vagotomy, it was recorded concomitantly by gamma scintigraphy. Semi-solid (porridge) and liquid (glucose 10%) meals were tested. Truncal vagotomy significantly increased insulin release compare to intact animals after glucose (63.8%) and porridge (174.4%) meals in the early and the late absorption phases of insulin secretion, respectively. For the glucose meal, this effect could be explained by a vagally mediated change in gastric emptying rate, since insulin concentrations for a similar amount of nutrient propelled to the duodenum were not different in intact and truncal vagotomized animals. In contrast, after the porridge meal, truncal vagotomy was associated with a second, later occurring increase in circulating insulin, which could not be explained by changes in gastric emptying rate. These results demonstrate for the first time an inhibitory role of the vagus in the late meal absorption phase of insulin release.

Babesia divergens was cultivated in sheep erythrocytes in RPMI 1640 supplemented with 10% Fetal Calf Serum (FCS) or sheep serum. In vitro cultures in sheep red blood cells were initiated with human erythrocytes infected in vitro with B. divergens Rouen 1987 or with gerbil blood infected with several isolates from bovine origin. After the first subcultures on sheep erythrocytes, a ten-fold multiplication of the parasites was obtained within 48 h. Erythrocytes from three splenectomized sheep were infected in vitro with B. divergens; when parasitaemia reached 10%, the animals were inoculated with homologous parasitized erythrocytes. All sheep expressed hyperthermia with a peak between the 6th and the 9th day post-infection (p-i) and a transitory parasitaemia 10 days p-i. In vitro primary cultures were performed on two of these sheep, demonstrating the parasite persistence at very low parasitaemia in the infected animals. Splenectomized sheep can be used as a new model for B. divergens chronic infection.

Buffalo fasciolosis induced by Fasciola gigantica causes important economic losses in tropical areas of Asia. Detection of prepatent infection is essential to control this disease. Classical tools such as coprology, necroscopy or ELISA based on crude extracts from F. gigantica are poorly sensitive or specific. Purified antigens could be used to increase these parameters. Western blot analysis and mass spectrometry of a fraction of F. gigantica excretory–secretory products obtained by gel filtration showed that thioredoxin peroxidase could be a potential antigen for serodiagnosis: it was recognized from the 2nd week after infection, by all buffalo experimentally or naturally infected with F. gigantica but not by healthy animals.

We report 2 cases of babesiosis in immunocompetent patients in France. A severe influenza-like disease developed in both patients 2 weeks after they had been bitten by ticks. Diagnosis was obtained from blood smears, and Babesia divergens was identified by PCR in 1 case. Babesiosis in Europe occurs in healthy patients, not only in splenectomized patients

Experimental infections of Lymaea truncatula, using two susceptible snail populations (Berneuil, or Migné, central France) and four isolates of Fasciola hepatica miracidia differing in their mammalian host of origin (cattle, nutrias, rabbits, or sheep), were performed under laboratory conditions to determine whether the host of origin had an effect on the daily production of cercariae. Snails were each subjected to bimiracidial exposures and were then reared under semi-natural conditions (a constant temperature of 20 degrees C and natural photoperiod). Significantly lower values were noted in the rabbit groups for survival rates at day 30 post-exposure, as well as for prevalences of infection, snail growth. duration of shedding period, and the total numbers of cercariae these snails shed. The total number of cercariae shed by both nutria groups was significantly higher than those recorded in the six other infected groups. In the cattle, rabbit, and sheep (Berneuil only) groups, the peaks in the daily distribution of cercariae occurred between day 2 and day 4 after the first shedding, and the number of cercaria-shedding snails decreased with increasing number of shedding waves. In contrast, in the three other groups, the peaks were only observed between days 20 and 45. Snails shedding their cercariae during nine or more waves were numerous in these last groups. No infradian-type rhythm in the daily distribution of cercarial numbers over the shedding period was noted for any snail group. The highest production of F. hepatica cercariae in both nutria groups would be a consequence of a higher success rate of miracidia when they infected an allopatric population of snails. The absence of an infradian-type rhythm in the distribution of daily cercarial numbers in the eight groups suggests that this rhythm, if it occurs, would only be influenced by temperature and thus be limited to periods with optimal conditions for cercarial shedding.

With the objective of studying the role of wild fauna in the epidemiology of fasciolosis disease, a definitive wild-host inventory was carried out in a french farm where infected domestic hosts (cows) cohabit with wild potential ones. Liver flukes, faecal eggs and antibodies were looked for in lagomorphs (Oryctolagus cuniculus) and rodents (Myocastor coypus, Ondatra zybethicus, Rattus norvegicus, Arvicolasapidus and micromammal species) trapped in the study area. Presence of Fasciola hepatica was detected in two species: O. cuniculus and M. coypus. Infection rates were respectively 34 % (42/124) and 55 % (106/193). Liver flukes were found in 78 M. coypus (n = 192) and 1 1 O. cuniculus (n = 35). No other species was infected by F. hepática. The number of animals shedding fluke eggs was higher in M. coypus (49 out of 1 27 sampled; 38.6 %) than in O. cuniculus (two out of 17 sampled; 11.7 %). The results indicate that M. coypus may play a role in the maintenance and the dissemination of F. hepatica in various environments and open a discussion on the role of other natural wild hosts., Afin d'étudier le rôle de la faune sauvage dans l'épidémiologie de la fasciolose, un inventaire des rongeurs et des lagomorphes hôtes sauvages de Fasciola hepatica a été effectué dans une ferme française où des bovins infestés cohabitent avec des animaux sauvages potentiellement hôtes. La présence de douves hépatiques, d'oeufs dans les fèces et d'anticorps sanguins a été recherché chez des lagomorphes (Oryctolagus cuniculus) des rongeurs (Myocastor coypus, Ondatra zybethicus, Rattus norvegicus, Arvicola sapidus et micromammifères) capturés sur la zone d'étude. La présence de Fasciola hepatica a été observée chez deux espèces : O. cuniculus et M. coypus. Les taux d'infestation sont respectivement de 34 % (42/124) et 55 % (106/193). Des douves ont été isolées dans 78 foies de M. coypus (n = 192) et 11 foies de O. cuniculus (n = 35). Aucune autre espèce n'est infestée. Le nombre d'animaux infestés excréteurs d'oeufs est plus élevé chez M. coypus (49 sur les 127 échantillonnés ; 38,6%) que chez O. cuniculus (2 sur les 17 échantillonnées; 11,7 %). Les résultats témoignent du rôle possible de M. coypus dans le maintien et la dissémination de F. hepatica et permettent de discuter du rôle des autres hôtes sauvages

The distribution of lymphocyte subpopulations (TCD4+ , TCD8+, T C D 4 3 + and l g + cells), macrophages and eosinophils were analysed in the inflammatory infiltrates associated with hepatic lesions and in hepatic lymph nodes (HLN) from rats experimentally infected with F. hepatica and necropsied 1, 2, 3, 4, 6 and 8 week post infection (WPI). W e also investigated the fixation of immunoglobulin isotypes on migrating flukes in the liver. As early as 1WPI, portal tract areas surrounding migratory tunnels were infiltrated with immune and inflammatory cells. The dominant cells were eosinophils and to lesser extent, macrophages and lymphocytes (TCD4+, T C D 8 + and B). Most of the inflammatory and immune cells reached the posterior part of flukes, whereas in front of the parasites these cells were fewer in number. Except for eosinophils, no immune cells penetrated through granuloma consisting of hepatic necrotic cells. As early as 1 W P I , IgM could be detected in the liver, and to a lesser extent IgA, lgG2 a and lgG2 b . At 2 W P I , IgE and IgG, began being detected. lgG2 c was detectable at 3 W P I . In HLN, we observed numerous microscopic follicles in the cortical zone with proliferation of germinal centres and medullary cords. The protective role of infiltrating cell populations and immunoglobulin isotypes and possible mechanisms of immune evasion by the parasite are discussed., L'objectif de cette étude était de caractériser la distribution des différentes cellules immunitaires et inflammatoires. Les souspopulations lymphocytaires (TCD4+, TCD8+, TCD43+ et les cellules lg+), ainsi que les macrophages et les éosinophiles, associés aux lésions hépatiques et dans les ganglions lymphatiques ont été étudiés chez des rats infestés expérimentalement par Fasciola hepatica. Nous avons recherché la fixation des différentes isotypes d'immunoglobulines sur les douves en migration et comparé ces résultats avec la réponse humorale systémique. Dès la première semaine post infestation (SPI), les espaces portes hépatiques sont infiltrés par des cellules inflammatoires et immunitaires. Les cellules dominantes sont des éosinophiles et dans une moindre part, des macrophages et des lymphocytes (TCD4+, TCD8+ et B). La plupart de ces cellules n'atteignent que la partie postérieure du parasite, alors qu'elles sont moins nombreuses devant celui-ci. A l'exception des éosinophiles, aucune autre cellule ne pénètre dans le granulome constitué de nombreuses cellules hépatiques nécrotiques. On détecte les IgM dans le foie dès la 1SPI, et avec une moindre intensité les IgA, lgG2a et les lgG2b. A 2SPI les IgE et les lgG1 deviennent détectables, et enfin à la 3SPI les lgG2c. Au niveau des ganglions lymphatiques hépatiques, nous observons dans la zone corticale plusieurs follicules lymphoïdes microscopiques avec une prolifération des centres germinatifs et des cordons medullaires. Le rôle protecteur des différentes cellules infiltrées et les différentes isotypes d'immunoglobulines, et les éventuels mécanismes d'échappement parasitaires vis-à-vis du système immunitaire sont discutés.

To determine characteristics of natural transmission of Babesia sp. EU1 and B. divergens by adult Ixodes ricinus ticks, we examined tick salivary gland contents. We found that I. ricinus is a competent vector for EU1 and that their sporozoites directly invade erythrocytes. We conclude that EU1 is naturally transmitted by I. ricinus.

The present study was designed to determine whether IFN gamma and IL-10 were secreted by peripheral blood mononuclear cells (PBMC) and hepatic lymph node mononuclear cells (HLNMC) from 17 Fasciola hepatica infected sheep after in vitro stimulation by Fasciola hepatica excretory-secretory products (FhESP) during the first six weeks of two different infections. The IFN gamma concentration in mononuclear cells (MC) culture supernatants was determined by sandwich ELISA. The presence of IL-10 in MC culture supernatants was determined by the capacity of these to inhibit, with or without monoclonal antibodies to IL-10, the NO production of recombinant bovine IFN gamma (rBoIFN gamma) activated monocytes. FhESP-stimulated PBMC and HLNMC produced IFN gamma in culture supernatants from DPI 7 (day post-infestation 7) to DPI 14. Culture supernatants of PBMC stimulated with FhESP first induced an increase in the NO production of rBoIFN gamma activated monocytes. After 2 or 3 weeks of infection, MC culture supernatant reduced the NO production of rBoIFN gamma activated monocytes. From DPI 35, anti-IL-10 antibodies addition restored or enhanced NO production. During sheep fasciolosis, IFN gamma production increased only until the first two weeks post infection. IL-10 could be secreted throughout the first six weeks of infection and could inhibit monocytes from DPI 35.

The length and width of 1297 Fasciola hepatica eggs shed in cattle hosts, 337 in sheep and 199 in nutria, were measured from several parts of France. The data were compared with those obtained from other studies in Spain, France (where rats were also investigated), Germany and the Netherlands. One way analysis of variance and discriminant analysis were used to assess differences between host origins. The distribution of length and width of eggs were analysed using skewness and kurtosis Fisher coefficients. The eggs recovered from sheep, cattle, rodents and lagomorphs were different in size: the eggs found in rodents (length L × width W in μm: 8592) and lagomorphs (L × W in μm: 9100) were smaller than those found in sheep and cattle (L×W in μm: 10,000). These morphological differences in F. hepatica eggs were host-induced in rats (L×W in μm: 9709 in cattle to 8949 in rats) and rabbits (L×W in μm: 9709 in cattle to 8432 in rabbits). These differences in size of eggs might correspond to their being less able to develop into miracidia in less frequent hosts such as rodents and rabbits.

An enzyme linked immunosorbent assay (ELISA) for bovine babesiosis caused by Babesia divergens was developed to analyse the evolution of the serological status of cattle living in an enzootic area. The antigen used was a soluble extract of B. divergens obtained from in vitro culture. Specificity, evaluated with negative sera, was 96.6%. The ELISA was compared to indirect immunofluorescence analysis (IFA) on naturally or experimentally infected animals. It appeared that IFA was positive for at least seven or eight weeks; on the contrary, B. divergens-specific antibodies were only transitorily detected by ELISA. Furthermore, the ELISA was more sensitive than the IFA for the detection of post-infection antibody increases, particularly when infection-pressure was low. These results suggest that IFA and ELISA could be complementary tools in epidemiological surveys; indeed, this ELISA could be the most efficient tool to detect new infections in cohort monitoring.

International audience; Babesiosis is a tick-transmitted disease of mammalian hosts, caused by the intraerythrocytic protozoan parasites of the genus Babesia. Transmission of Babesia parasites from the vertebrate host to the tick is mediated by sexual stages, the gametocytes which are the only intraerythrocytic stages that survive and develop inside the vector. Very few data are available concerning these parasite stages and some markers are needed in order to refine our knowledge of Babesia life cycle inside the tick and to permit the monitoring of parasite transmission from vertebrate to vector. We previously identified some potential markers of the Babesia divergens gametocytes using an in silico post-genomic approach based on sequence identity between the available genomes of Plasmodium and Babesia spp. Here, one of the identified proteins, BdCCp2, was validated as a marker of sexual stages of B. divergens, in infected ticks challenged with antisera directed against recombinant BdCCp2 protein. The BdCCp2 protein was detected by Western blot in some infected ticks, as a discrete band of approximately 171 kDa, while no signal was detected in the laboratory-reared non-infected tick. BdCCp2 was also detected, by immunohistochemical analyses, in piriform or ovoid bodies, measuring 2.5-4.5 μm in diameter, in the gut of partially engorged ticks that were experimentally infected. This molecular marker can then be used in the future to characterize and analyze the biology of B. divergens gametocytes.

A new gene of Babesia sp. BQ1 (Lintan) (BQP35) was cloned by screening a merozoite cDNA expression library with infected sheep serum and using rapid amplification of cDNA ends (RACE). The nucleotide sequence of the cDNA was 1140bp with an open reading frame (ORF) of 936bp encoding a 35-kDa predicted polypeptide with 311 amino acid residues. Comparison of BQP35 cDNA and genomic DNA sequences showed that BQP35 does not possess an intron. Recombinant BQP35 (rBQP35), expressed in a prokaryotic expression system, showed abnormally slow migration on SDS-PAGE. Gel shifting, amino acid sequence and in silico disorder region prediction indicated that BQP35 protein has characteristics of intrinsically unstructured proteins (IUPs). This is the first description of such proteins in the Babesia genus. BQP35 induced antibodies production as early as one week after Babesia sp. BQ1 (Lintan) infection in sheep. No cross-reaction was observed with sera from sheep infected with other ovine piroplasms dominant in China, except with Babesia sp. Tianzhu. The interest of BQP35 as a diagnostic antigen is discussed.

Buffalo fasciolosis induced by Fasciola gigantica causes important economic losses in tropical areas of Asia. Detection of prepatent infection is essential to control this disease. Classical tools such as coprology, necroscopy or ELISA based on crude extracts from F. gigantica are poorly sensitive or specific. Purified antigens could be used to increase these parameters. Western blot analysis and mass spectrometry of a fraction of F. gigantica excretory-secretory products obtained by gel filtration showed that thioredoxin peroxidase could be a potential antigen for serodiagnosis: it was recognized from the 2nd week after infection, by all buffalo experimentally or naturally infected with F. gigantica but not by healthy animals.