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International audience; Highlights: • Organic farmers are well informed on alternatives to anthelmintics but a few put them into practice. • The determinants of anthelmintic drench frequency are variable at different systems of production. • Targeted Selective Treatment is not commonly incorporated by organic farmers. • Dairy goat and meat sheep organic production systems have distinct approaches for nematode control.Abstract:To counter the global spread of anthelmintic resistance (AR), considerable efforts have been invested in the development and dissemination of sustainable alternatives to control gastrointestinal nematode (GIN) infections in small ruminants. The degree to which these have been accepted and integrated by farmers, particularly in organic systems, where the drive to reduce chemical inputs is arguably even more pressing, has been little studied. To identify whether more comprehensive actions are needed to support the uptake of alternative GIN controls amongst organic farmers, this study conducted a survey in five European countries on organic dairy goat and meat sheep farmers to gain insight into current GIN control strategies and farmer attitudes towards AR and alternative measures in these countries. The structured survey was disseminated in the five European countries Switzerland, France, Netherlands, Lithuania and United Kingdom, receiving a total of 425 responses, 106 from organic dairy goat farmers and 319 from organic meat sheep farmers. Regression analyses were carried out to identify factors impacting anthelmintic drenching on meat sheep production systems, whereas all data were analysed descriptively. Four key findings emerged: i) The frequency of anthelmintic treatments averaged less than two per animal a year in all production systems; ii) Overall, organic farmers seemed well informed on the availability of alternative GIN control methods, but fewer stated to put them into practice; iii) Targeted selective treatment (TST) strategies of anthelmintics appears to be not commonly incorporated by organic farmers; iv) Despite operating under national and EU organic regulations, each of the organic dairy goat (Switzerland, France and Netherlands) and meat sheep (Switzerland, Lithuania and United Kingdom) production systems developed distinct approaches for GIN control. To increase uptake of alternatives to GIN control and optimise anthelmintic use, initiatives that promote research dissemination, farmer participatory and knowledge transfer activities at national level would be desirable.

The nature and strength of interactions entertained among helminths and their host gut microbiota remain largely unexplored. Using 40 naturally infected Welsh ponies, we tracked the gut microbiota-cyathostomin temporal dynamics during parasite community removal and reassembly, and the associated host immune response. Infected ponies harboured 14 species of cyathostomins, overwhelmed by the abundance of Cylicocyclus nassatus. Parasite carriers exhibited gut environment modifications, higher Shannon entropy and orderly rearrangements of prokaryotic assemblages, with protective Clostridia species contributing to the successional nemabiome-microbiota crosstalk. Yet, the gut ecosystem was remarkably stable, and the host systemic response defined enrichment for B-cell activation and IgA production without corresponding changes in parasite burdens. Therefore, Clostridia microbial protection likely reduced fluctuating dynamics between the microbiota-parasite-host triad and favoured parasite tolerance. The system stability was disrupted by pyrantel treatment and parasite removal, with dire early consequences on the gut environment, microbiota diversity, and cytokine networks while highlighting the detrimental effect of cyathostomin burdens on Enterococcus spp. Both ecological communities were highly resilient to disturbance and recovered their pre-treatment compositions but for Cylicostephanus longibursatus in the parasite community. However, gut microbiotas failed to restore their original stability and shifted towards an interacting unstable state, with transient coexistence between Clostridia and core bacterial taxa, e.g. Fibrobacter and Prevotella, evoking their crucial role as stabilising forces for this new equilibrium. These observations highlight how anthelmintic treatment alters the gut microbiota stability and open new perspectives for adding nutritional intervention to current parasite management strategies in the field.

This document was prepared thanks to the collective expertappraisal, carried out by the Anses’expert group‘GECUCovid-19’(ANSES opinion 2020-SA-0037), chaired by Sophie Le Poder and whose members for the animal health component are cited in the authors.; International audience; In late December 2019, an outbreak of clustered cases of pneumonia associated with a novel coronavirus was reported by the Chinese authorities to the World Health Organization (WHO). Several initial confirmed cases were linked to a wetmarket selling live animals and seafood products in Wuhan(Hubei province), China (Huang et al.,2020). On 30 January 2020, the WHO declared the outbreak a Public Health Emergency of International Concern. On 11 February 2020, the causative pathogen was officially named Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), responsible for Coronavirus Disease 2019 (COVID-19) (DuToit, 2020). Severe Acute Respiratory Syndrome Coronavirus 2 is mainly transmitted from person to person, by direct or indirect contact, through infectious microdroplets emitted wheninfected individuals spit, sneeze or cough (Bernard Stoecklin et al.,2020). The massive circulation of this new pandemiccoronavirus with a probable zoonotic origin raised questions on its ability to spillover to animal species and on the potential consequences of such events on both animals and humans. This public health concern came to the attention of animal health authorities given the close contacts between humans and domestic animals. Therefore, in France, the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) established an Emergency Collective Expert Appraisal Group (Groupe d’Expertise Collective d’Urgence, GECU‘Covid-19’). The GECU ‘Covid-19’ urgently convened on 4 March 2020 and 8 April 2020 to conduct an evaluation of the potential role of domestic animals in the ongoing COVID-19 pandemic.

International audience; Mycoplasma wenyonii, a hemoplasma infecting cattle, was never detected in France. In 2014, evocative inclusions were observed in erythrocytes from cattle presenting milk drops, anemia, and edema in Brittany (France). A survey was then initiated to investigate the epidemiological situation and correlate mycoplasma detection with clinical signs. For this purpose, a new PCR assay targeting polC gene was designed. Comparative results with published PCR assays place this new one as more specific, allowing a one-step diagnosis without further sequencing. A total of 181 cows were included in this study and 4.97% (n=9) were positive, resulting in the first molecular identification of M. wenyonii in France. All positive animals presented anemia, edema and milk drop. When selecting animals presenting evocative clinical signs, the prevalence of M. wenyonii in Brittany was estimated to 25.6%. Further studies are needed to evaluate the importance of the infection, the implication of arthropods and the existence of asymptomatic carriers.

International audience; Prions are transmissible protein pathogens most reliably detected by a bioassay in a suitable host, typically mice. However, the mouse bioassay is slow and cumbersome, and relatively insensitive to low titers of prion infectivity. Prions can be detected biochemically in vitro by the protein misfolding cyclic amplification (PMCA) technique, which amplifies diseaseassociated prion protein but does not detect bona fide prion infectivity. Here, we demonstrate that Drosophila transgenic for bovine prion protein (PrP) expression can serve as a model system for the detection of bovine prions significantly more efficiently than either the mouse prion bioassay or PMCA. Strikingly, bovine PrP transgenic Drosophila could detect bovine prion infectivity in the region of a 10-12 dilution of classical bovine spongiform encephalopathy (BSE) inoculum, which is 106-fold more sensitive than that achieved by the bovine PrP mouse bioassay. A similar level of sensitivity was observed in the detection of H-type and L-type atypical BSE and sheep-passaged BSE by bovine PrP transgenic Drosophila. Bioassays of bovine prions in Drosophila were performed within 7 weeks, whereas the mouse prion bioassay required at least a year to assess the same inoculum. In addition, bovine PrP transgenic Drosophila could detect classical BSE at a level 105-fold lower than that achieved by PMCA. These data show that PrP transgenic Drosophila represent a new tractable prion bioassay for the efficient and sensitive detection of mammalian prions, including those of known zoonotic potential.

International audience; Avian pox is an infectious disease caused by avipoxviruses (APV), resulting in cutaneous and/or tracheal lesions. Poxviruses share large genome sizes (from 130 to 360 kb), featuring repetitions, deletions or insertions as a result of a long-term recombination history. The increasing performances of next-generation sequencing (NGS) opened new opportunities for surveillance of poxviruses, based on timely and affordable workflows. We investigated the application of the 3rd generation Oxford Nanopore Minion technology to achieve real-time whole-genome sequencing directly from lesions, without any enrichment or isolation step. Fowlpox lesions were sampled on hens, total DNA was extracted and processed for sequencing on a MinION, Oxford Nanopore. We readily generated whole APV genomes from cutaneous or tracheal lesions, without any isolation or PCR-based enrichment: Fowlpox virus reads loads ranged from 0.75% to 2.62% and reads up to 61 kbp were generated and readily assembled into 3 APV complete genomes. This long read size eases the assembly step and lowers the bioinformatics capacity requirements and processing time compared to huge sets of short reads. The complete genome analysis confirmed that these Fowlpox viruses cluster within clade A1 and host full length reticuloendotheliovirus (REV) inserts. The pathobiological relevance of REV insert, although a classical feature of fowlpoxviruses (FPVs), should be further investigated. Surveillance of emerging poxviruses could greatly benefit from real-time whole genome sequencing.

International audience; Mastitis and associated pain have been identified as a major health and welfare problem affecting dairy cows, however little is known about how cows emotionally experience this illness. Qualitative behaviour assessment (QBA) is a 'whole animal' methodology for assessing animal emotion, through description and quantification of the expressive qualities of an animal's dynamic style of behaving (eg as relaxed, anxious). The aim of this study was to use QBA to investigate whether emotional expression in dairy cows is affected by an experimental intra" mammary challenge (mastitis) with Escherichia coli, and to investigate the relationship of QBA scores with nine other clinical, physiological and behavioural welfare indicators. Six Holstein-Friesian cows were inoculated with E. coli in one healthy quarter. Evolution of the disease was assessed using bacteriological growth and somatic cell counts (SCC). The cows' response to the challenge was assessed using QBA, clinical observations, data loggers, rumen temperature sensor, and physiological indicators (inflammation, stress) at ten time-points defining the phase of the disease: before inoculation (Phase 0: 0 h), in the pre-clinical Phase (Phase 1: 8 h), in the acute phase (Phase 2: 12 h, 16 h, 24 h) and in the remission phase (Phase 3 : 32 h, 40 h, 56 h, 64 h and 80 h post-inoculation (hpi)). Principal Component Analysis of QBA scores identified two main dimensions of cow expression: PC1, ranging from active/vigorous/happy/bright to suffering/dejected/lethargic, and PC2, ranging from fearful/tense/anxious to confident/calm/relaxed, together explaining 58% of the total variation. QBA PC1 and PC2 scores varied with mastitis phases: QBA PC1 scores decreased by 4.09 in Phase 2, and by 1.98 in Phase 3, reflecting suffering/dejected/lethargic expressivity. QBA PC2 scores decreased by 1.91 in Phase 3, reflecting a confident/calm/relaxed expressivity. Clinical and physiological welfare indicators were associated with QBA. The higher the udder severity score, the body temperature, the concentrations of cortisol, SAA, TNF-alpha, and IL-1 beta, the more the cows were suffering/dejected/lethargic (PC1) (coefficients:-0.51,-0.92,-2.46, 7.52 x 10-5,-0.72,-1.13 respectively). These findings indicate that dairy cows experienced negative emotional state in the acute phase and positive emotional state in the remission phase of mastitis. This suggests that provision of pain-relief treatment during mastitis may improve animal welfare, and potentially lead to faster disease remission. However the sample size of this study was small, and larger controlled studies are needed to further investigate these findings and hypotheses. The sensitivity of QBA in this small study suggests it could potentially be a useful tool for E. coli mastitis detection.

International audience; Breeding sheep for enhanced resistance to gastrointestinal parasites is a promising strategy to limit the use of anthelmintics due to the now widespread resistance of parasites to these molecules. This paper reports the genetic parameters estimated for parasite resistance and resilience traits in the Blond-faced Manech dairy sheep breed and the putative impacts of the selection for resistance to gastrointestinal nematodes (GIN) on farms. Two datasets were used. First, the rams of the selection scheme were artificially infected twice with L3 Haemonchus contortus larvae. Faecal egg counts (FEC) and packed cell volume (PCV) loss were measured 30 days after each infection. Secondly, the FEC, PCV and body condition score (BCS) (1–6 measures per ewe) of naturally infected ewes on farms were measured in the spring, summer and autumn over a two-year period. Genetic parameters were estimated for each dataset independently but also globally based on the pedigree connections between the two datasets. For the experimentally infected sires, the FEC following the second infection was moderately heritable (heritability: 0.35) and strongly correlated with FEC after the first infection (genetic correlation: 0.92). For the naturally infected ewes, FEC was also heritable (0.18). Using the two datasets together, a genetic correlation of 0.56-0.71 was estimated between the FEC values of the experimentally infected rams and naturally infected ewes. Consequently, the genetic variability of parasite resistance is similar whatever the physiological status (males or milking/pregnant ewes) and the infection conditions (experimental infection with one parasite or natural infection with several parasites). In practice, when the sire population is divided into two groups based on their genetic value, the FEC of the ewes born to the 50% most resistant sires is half that of the ewes born to the 50% most susceptible sires. Our study shows the feasibility and efficiency of genetic selection for parasitism resistance based on the sires FEC records to improve parasite resistance in naturally grazing ewes. For breed improvement, and to increase the selection pressure on parasite resistance, it seems more appropriate to measure FEC values on rams after experimental infection rather than on ewes in natural infection conditions because this limits the number and standardizes the conditions of FEC measurements.

International audience; In rabbit production, the use of dehydrated sainfoin, a Legume containing phenols and condensed tannins (CT), has received recent attention because of its nutraceutical properties. Here, we aimed to compare the nutritive value of dehydrated Perly cultivar sainfoin for a first cut (SC1: crude protein = 200 g/kg, Acid detergent fiber (ADFom) = 208 g/kg, CT = 11.8 g/kg), or a third cut (SC3: crude protein = 159 g/kg, ADFom = 228 g/kg, CT = 17.5 g/kg). The digestibility of two sets of 4 diets, made either with SC1 or with SC3, and containing either 0, 120, 240, or 360 g/kg of dehydrated sainfoin (DS0, DS120, DS240, DS360) in dilution with a basal mixture was compared based on a regression statistical procedure. A direct measure of the nutritive value of SC1 was performed with a supplemental diet containing 980 g/kg (DS980) of SC1. In trial 1, four groups of 12 growing rabbits received SC3 diets. In the trial 2, five groups of 8-9 rabbits received SC1 diets. Rabbits were allotted at weaning (35 days), housed individually in metabolism cages and fed ad libitum during six weeks. Sainfoin digestibility was measured for both trials in 6 weeks old rabbit, and in 8 weeks old rabbit only for trial 2. The digestibility of energy and particularly that of protein linearly decreased with the increase in SC3 incorporation in diets (P < 0.001). Using a regression procedure, SC3 digestible energy (DE) and protein (DP) concentrations were respectively 6.70 +/- 0.15 MJ DE/kg and 53 +/- 4 g DP/kg as fed, corresponding respectively to a 40 % and 33 % digestibility coefficient. On the contrary energy digestibility was relatively stable from 0 to 360 g/kg SC1 incorporation in diets, in both 6 wks. and 8 wks. old rabbits whereas the digestibility of protein decreased linearly with SC1 incorporation in diets (P < 0.001) as observed with SC3 incorporation. SC1 DE and DP concentration were respectively 8.84 +/- 0.25 MJ DE/kg, corresponding to an energy digestibility of 58 %, and 79 +/- 5 g DP/kg corresponding to a protein digestibility coefficient of 40 %. Nitrogen retention coefficients slightly decreased with SC3 incorporation. With SC1 incorporation, nitrogen retention coefficients were stable. With SC3 incorporation level the protein digestibility decreased sharper (P < 0.05) than for SC1. The DE content of SC1 calculated by regression gave similar results than a direct measurement (DS980), while the DP content was lower by regression compared to the direct measure (74 vs 92 g/kg). Thus for future assays of sainfoin nutritive value the use of a direct measure could be recommended for DE estimation.

International audience; Equine herpesvirus 1 (EHV-1) is a causative agent of respiratory disorders, abortion and myeloencephalopathy in horses and has an important impact on equine health and economy. Several bacterial artificial chromosomes have already been developed and enabled identification and functional characterization of EHV-1 genes. Unfortunately, little is known about its replication. Here, the ANCHOR system was inserted by targeted homologous recombination into the equine herpesvirus genome. This insertion led to the conversion of EHV-1 DNA to autofluorescent spots easily detectable by fluorescence microscopy, and enabled production of an auto-fluorescent EHV-1 ANCHORGFP with tropism and replication kinetic like the parental strain. High resolution imaging allowed first visualization of EHV-1 replication from apparition of first viral genome to large replicative centers, in single cells or inside syncytia. Combined with high content microscopy, EHV-1 ANCHORGFP leads to identification of auranofin and azacytidine-5 as new potential antivirals to treat EHV-1 infection.

International audience; Ethnopharmacological relevance: Salt-tolerant plants are well adapted to the harsh conditions of the Mediterranean region, where have been used traditionally as food and medicines for human and animals. In addition, various species are currently recognized as sources of metabolites with pharmacological, cosmetical and nutraceutical interest. Nevertheless, ethnoveterinary data on salt-tolerant plants are dispersed in the literature and there are few discussions on its veterinary potential. Having in mind the rising interest on organic farming, alternatives to chemical substances in livestock production and concern for animal health and welfare practices, these plants may represent an untapped resource for animal management and veterinary purposes. In this sense, the purpose of this work is to summarize the ethnoveterinary knowledge on salt-tolerant plants described in the Mediterranean region, raising awareness to the potential of this group of plants to be used in veterinary science, targeting especially ruminants.Material and methods: Literature search (2000-2020) was conducted using Web of Science and Science Direct databases. Ethnoveterinary reports (EVR) concerning salt-tolerant plants were summarized and filtered for ruminants. From the final 29 publications, EVR concerning therapeutic uses were categorized according to its ATCvet code and results analyzed. Results: A total of 221 EVR were identified from 39 plants, belonging to 21 plant families, targetting ruminants. Ten EVR (4.5%) concerned uses of salt-tolerant species as animal feed, while around 75% of therapeutic uses was represented by three categories: alimentary tract and metabolism (QA; n = 75), dermatologicals (QD; n = 53) and genitourinary system and sex hormones (QG; n = 41). Pistacia lentiscus L., Foeniculum vulgare Mill., Dittrichia viscosa (L.) Greuter, Plantago major L. and Hordeum vulgare L. were the most cited species in the latter categories.Conclusions: The ethnoveterinary knowledge on salt-tolerant species hints some plants of veterinary pharmacological potential, but other species deserve further notice. This information should serve as a basis and, coupled with the currently available scientific data on bioactive properties and chemical composition of salt-tolerant species, inspire additional research on the exploitation of this botanical group, as sources of novel products for ruminant nutrition, health and quality of its products.

Highlights • Avipoxviruses evolution rate: 2–8 × 10−5 substitution/site/year. • Mean time of divergence from common ancestor: 10,000–30,000 years. • Purifying selection in avipoxviruses P4b, cnpv186 and DNA polymerase genes., Avipoxviruses are divided into three clades: canarypox-like viruses, fowlpox-like viruses, and psittacinepox-like viruses. Several molecular clock and demographic models available in the BEAST package were compared on three avipoxvirus genes (P4b, cnpv186 and DNA polymerase genes), which enabled to determine that avipoxviruses evolved at a rate of 2–8 × 10−5 substitution/site/year, in the range of poxviruses previously reported evolution rates. In addition, the date of mean time of divergence of avipoxviruses from a common ancestor was extrapolated to be about 10,000–30,000 years ago, at the same period as modern poxvirus species. Our findings will facilitate epidemiological investigations on avipoxviruses’ spread, origin and circulation.

Newcastle disease (ND) and infectious bronchitis (IB) are two major viral diseases affecting the respiratory tracts of birds and whose impact on African poultry is still poorly known. In the present study we aimed at assessing NDV and IBV prevalences in Ivory-Coast by molecular screening of > 22,000 avian swabs by nested PCR and by serology testing of close to 2000 avian sera from 2010 through 2012. The NDV and IBV seroprevalences over the study period reached 22% and 72%, respectively. We found 14.7% pooled swabs positive by PCR for NDV and 14.6% for IBV. Both pathogens are therefore endemic in Ivory-Coast. Economic losses associated with NDV and IBV infections still need to be evaluated., Highlights • Surveillance of avian influenza virus is found negative in backyard poultry farm. • Study of Newcastle disease and infectious bronchitis as differential diagnosis diseases • Newcastle disease virus seroprevalence is much lower than infectious bronchitis virus. • First study of infectious bronchitis revealed high prevalence in backyard poultry. • Both pathogens are endemic, cause economic losses and need to be fully evaluated.

Avian metapneumovirus (aMPV) infects respiratory and reproductive tracts of domestic poultry, often involving secondary infections, and leads to serious economic losses in most parts of the world. While in general disease is effectively controlled by live vaccines, reversion to virulence of those vaccines has been demonstrated on several occasions. Consensus sequence mutations involved in the process have been identified in more than one instance. In one previous subtype A aMPV candidate vaccine study, small subpopulations were implicated. In the current study, the presence of subpopulations in a subtype B vaccine was investigated by deep sequencing. Of the 19 positions where vaccine (strain VCO3/50) and progenitor (strain VCO3/60616) consensus sequences differed, subpopulations were found to have sequence matching progenitor sequence in 4 positions. However none of these mutations occurred in a virulent revertant of that vaccine, thereby demonstrating that the majority progenitor virus population had not survived the attenuation process, hence was not obviously involved in any return to virulence. However within the vaccine, a single nucleotide variation was found which agreed with consensus sequence of a derived virulent revertant virus, hence this and other undetected, potentially virulent subpopulations, can be involved in reversion. Much deeper sequencing of progenitor, vaccine and revertant may clarify whether problematic virulent subpopulations are present and therefore whether these need to be routinely removed during aMPV vaccine preparation prior to registration and release. Avian metapneumovirus (aMPV) infects respiratory and reproductive tracts of domestic poultry, often involving secondary infections, and leads to serious economic losses in most parts of the world. While in general disease is effectively controlled by live vaccines, reversion to virulence of those vaccines has been demonstrated on several occasions. Consensus sequence mutations involved in the process have been identified in more than one instance. In one previous subtype A aMPV candidate vaccine study, small subpopulations were implicated. In the current study, the presence of subpopulations in a subtype B vaccine was investigated by deep sequencing. Of the 19 positions where vaccine (strain VCO3/50) and progenitor (strain VCO3/60616) consensus sequences differed, subpopulations were found to have sequence matching progenitor sequence in 4 positions. However none of these mutations occurred in a virulent revertant of that vaccine, thereby demonstrating that the majority progenitor virus population had not survived the attenuation process, hence was not obviously involved in any return to virulence. However within the vaccine, a single nucleotide variation was found which agreed with consensus sequence of a derived virulent revertant virus, hence this and other undetected, potentially virulent subpopulations, can be involved in reversion. Much deeper sequencing of progenitor, vaccine and revertant may clarify whether problematic virulent subpopulations are present and therefore whether these need to be routinely removed during aMPV vaccine preparation prior to registration and release.

International audience; An in vitro screening of the anti-apicomplexan activity of 51 compounds, stemming from our chemical library and from chemical synthesis, was performed. As a study model, we used Toxoplasma gondii (T. gondii), expressing β-galactosidase for the colorimetric assessment of drug activity on parasites cultivated in vitro. This approach allowed the validation of a new series of molecules with a biphenylimidazoazine scaffold as inhibitors of T. gondii growth in vitro. Hence, 8 molecules significantly inhibited intracellular replication of T. gondii in vitro, with EC50 < 1 μM, while being non-toxic for human fibroblasts at these concentrations. Most attractive candidates were then selected for further biological investigations on other apicomplexan parasites (Neospora caninum, Besnoitia besnoiti, Eimeria tenella and Plasmodium falciparum). Finally, two compounds were able to inhibit growth of four different apicomplexans with EC50 in the submicromolar to nanomolar range, for each parasite. These data, including the broad anti-parasite spectrum of these inhibitors, define a new generation of potential anti-parasite compounds of wide interest, including for veterinary application. Studies realized on E. tenella suggest that these molecules act during the intracellular development steps of the parasite. Further experiments should be done to identify the molecular target(s) of these compounds.

International audience; The prevalence of neonatal mortality is high in the canine species and far from well-studied. In most domestic neonates, an appropriate colostrum intake is a key element of the control of neonatal mortality. The aim of this study was to evaluate the impact of passive immune transfer on puppy mortality, assessed through serum immunoglobulin G (IgG) concentration at 2 days of age. Factors impacting passive immune transfer and the value of an oral immunoglobulin supplementation to prevent it were also analyzed. A total of 149 puppies from 34 litters (12 breeds) within one breeding kennel were included. Blood samples were collected at 2 days of age and colostrum was collected from their dams 1 day after whelping to assay IgG concentration. Puppies were weighed at birth and at 2 days of age for calculation of growth rate. Mortality was recorded until 3 weeks of age. Seventy randomly assigned puppies were orally supplemented with hyper-immunized adult plasma twice within the first 8h of life. IgG concentration at 2 days of age was significantly correlated with weight gain during the first 2 days of life. The multivariable model with litter as a random effect demonstrated that neonatal mortality was not influenced by breed size, sex, supplementation, litter size, nor colostrum IgG concentration, but by puppy IgG concentration at 2 days of age. According to the ROC curve, the minimal IgG concentration at and below which puppies were at higher risk of death was determined at 230mg/dl. Puppy IgG concentration was significantly associated with growth rate, but not with breed size, sex, supplementation, litter size or colostrum IgG concentration in a multivariable model with litter as a random effect. This study demonstrates that neonatal mortality in puppies is related to the quality of passive immune transfer. The oral supplementation with hyper-immunized canine plasma neither decreased risk of mortality, nor improved serum IgG concentration at 2 days of age in puppies. Attention must thus be paid to early colostrum intake to control the neonatal mortality in puppies.

International audience; Parasitic infections with gastrointestinal nematodes (GINs) represent a major pathological threat associated with the outdoor production of various livestock species. Up to now, the control of these parasitic diseases essentially relied on the use of commercial anthelmintic drugs. However, resistance to anthelmintics is nowadays widespread in worm populations. Recent results indicate that bioactive tanniniferous plants represent a valuable option as an alternative to commercial drugs for the control of GINs. The pertinent use of tannincontaining fodders as nutraceuticals supposes a clear understanding of the mode of action against the worms. The objectives of this paper are: (1) to discuss the nature and quantity of the active molecules involved in the anthelmintic activity; and (2) to review and analyze the changes provoked to the various parasitic stages. The possible involvement of some main polyphenols to explain the bioactivity of some tannin-rich plants will be discussed as well as the possible effects on the various nematode stages, relying on data obtained either with the temperate forage, sainfoin (Onobrychis viciifoliae) or with the tropical legume tree (Lysiloma latisiliquum). The information on the mode of action will be related to the potential consequences for better field applications under entirely different environmental and ecological conditions of productions.

International audience; Recombinant poxviruses are well suited for the development of new vaccine vectors. Our previous data supported the idea that Myxomavirus (MYXV) is efficient at priming antibody responses in sheep. To provide definitive evidence on the potential of MYXV for vaccination against infectious diseases in ruminants, we investigated the immune protection provided by recombinant MYXV against bluetongue, a devastating disease in sheep. To test this concept, sheep were injected twice with an MYXV expressing the immunodominant VP2 protein (SG33-VP2). The SG33-VP2 vector promoted the production of neutralising antibodies and partially protected sheep against disease after challenge with a highly virulent strain of serotype-8 bluetongue virus (BTV-8). In contrast, an MYXV expressing both VP2 and VP5 proteins (SG33-VP2/5) elicited very little protection. The expression levels of the VP2 and VP5 proteins suggested that, greater than the co-expression of the VP5 protein which was previously thought to favour anti-VP2 antibody response, the high expression of VP2 may be critical in the MYXV context to stimulate a protective response in sheep. This highlights the requirement for a careful examination of antigen expression before any conclusion can be drawn on the respective role of the protective antigens. As a proof of principle, our study shows that an MYXV vaccine vector is possible in ruminants.

International audience; The present trial aimed at comparing the sensitivity of two in vitro methods, i.e. the larval migration inhibition assay (LMIA) and the larval exsheathment inhibition assay (LEIA), to evaluate the anthelmintic (AH) properties of tannin-rich plant extracts against Haemonchus contortus infective larvae. The two assays were applied on the same batch of H. contortus infective larvae exposed to water/acetonic extracts obtained from four tropical plants with different tannin contents: Acacia gaumeri, Brosimum alicastrum, Havardia albicans and Leucaena leucocephala. Increasing concentrations (0, 75, 150, 300, 600, 1200 _g/ml PBS) of lyophilized extracts were used in both in vitro assays. A general lineal model test was used to determine the dose-effect in the LMIA or the difference in the percentage of exsheathed larvae between the respective control and treated groups. The LMIA showed a dose-dependent AH effect for H. albicans (P < 0.001) and A. gaumeri (P < 0.05), but not for L. leucocephala and B. alicastrum. In contrast, the exsheathment process was significantly affected by all doses of H. albicans and A. gaumeri extracts and a significant dose-dependent effect was found for B. alicastrum and L. leucocephala. Calculation of lethal dose (LD) was possible with LEIA using B. alicastrum and L. leucocephala but not with H. albicans and A. gaumeri as the lowest tested concentration was achieving more than 50% inhibition. Calculation of LD with the LMIA results was not feasible. These results suggest that tannin-rich plant extracts are more potent inhibitors of the exsheathment of H. contortus L3 larvae than their motility. This information underlines the difference of sensitivity between methodological procedures to evaluate the AH properties of plant extracts on the same nematode stage.

International audience; In 2007, the world goat population was estimated at 831 million, compared with 1.09 billion sheep, but the goat population is expanding more rapidly. More than 90% of goats are found in developing countries, with the primary commodity being its meat. The commonly used description of the goat as the "cow of the poorest" underlines its importance for small farmers. However, in the developed world (eg, the European Union and much of North America), the value of goats relates to its select ability to produce high yields of milk and the increased returns associated with the dairy products, particularly artisanal cheeses. Therefore, the current success of goats seems to be related to 2 characteristics: (1) its ability to efficiently convert low-quality forages into high-quality protein sources, that is, milk and meat, in developing countries and (2) its ability to produce commodities for valuable niche markets in developed countries. In both systems, parasitism with helminths, and particularly nematodes of the gastrointestinal tract is a major threat for health and production.

International audience; Prion diseases are characterized by deposits of abnormal conformers of the PrP protein. Although large aggregates of proteinase K-resistant PrP (PrPres) are infectious, the precise relationships between aggregation state and infectivity remain to be established. In this study, we have fractionated detergent lysates from prion-infected cultured cells by differential ultracentrifugation and ultrafiltration and have characterized a previously unnoticed PrP species. This abnormal form is resistant to proteinase K digestion but, in contrast to typical aggregated PrPres, remains in the soluble fraction at intermediate centrifugal forces and is not retained by filters of 300-kDa cutoff. Cell-based assay and inoculation to animals demonstrate that these entities are infectious. The finding that cell-derived small infectious PrPres aggregates can be recovered in the absence of strong in vitro denaturating treatments now gives a biological basis for investigating the role of small PrP aggregates in the pathogenicity and/or the multiplication cycle of prions.

International audience; The existence of non-pathogenic RHDV strains was established when a non-lethal virus named rabbit calicivirus (RCV) was characterised in 1996 in Italy. Since then, different RNA sequences related to RHDV have been detected in apparently healthy domestic and wild rabbits, and recently a new lagovirus was identified in Australia. We have characterised from seropositive healthy domestic rabbits a non-lethal lagovirus that differs from RHDV in terms of pathogenicity, tissue tropism and capsid protein sequence. Phylogenetic analyses have revealed that it is close to the Ashington strain and to the RCV, but distinct. We proved experimentally that it is infectious but non-pathogenic and demonstrated that, contrary to the other described non-pathogenic lagoviruses, it induces antibodies that do not protect against RHDV. Our results indicate the existence of a gradient of cross-protection between circulating strains, from non-protective, partially protective to protective strains, and highlight the extent of diversity within the genus Lagovirus.

International audience; This study was carried out to evaluate the in vitro effect of Cucurbita moschata seed against the parasitic nematode of small ruminants Haemonchus contortus. Three extracts (aqueous, methanolic and dichloromethane) of C. moschata seed were tested in vitro on four developmental stages of H. contortus using egg hatch assay (EHA), larval development assay (LDA), L3 migration inhibition (LMI) assay and adult worm motility (AWM) assay. The highly significant (P < 0.001) ability to stop larval development (inhibition > 90% for each extract) and the negative effect of the dichloromethane and methanolic extracts on adult worm motility (inhibition of motility >59.2% after 24 h of incubation) compared to the negative controls, suggest anthelmintic properties of C. moschata seed against H. contortus. The active principles responsible for the activity could be secondary metabolites such as amino acid compounds or terpenoid compounds present in the extracts.

Thelazia callipaeda (Spirurida, Thelaziidae) is a small nematode living in the conjunctival sac of domestic and wild carnivores, rabbits and humans causing lacrimation, epiphora, conjunctivitis, keratitis and even corneal ulcers. The first autochthonous cases of thelaziosis affecting four dogs and one cat living in South Western France (Dordogne area) are reported and described. Nematodes recovered from the animals were morphologically identified as T. callipaeda and a partial region of the cytochrome oxidase c subunit 1 gene (cox1) was amplified by PCR from nematode specimens (from two dogs and the cat). In each case, this was shown to have an identical sequence to the haplotype 1 (h1) of T. callipaeda. So far, the arthropod acting as intermediate host of T. callipaeda eyeworms has not been identified in France although it might be Phortica variegata (Steganinae, Drosophilidae) as recently described in Italy.

A modified MacMaster method was tested to check its reliability for the diagnosis of bovine paramphistomosis in France. A total number of 148 fecal samples from cows examined post-mortem were analysed. Coprological results were in accordance with necropsic examinations. Bayesian techniques (Markov Chain Monte Carlo) were used to estimate the diagnostic parameters of each of these tests. Two scenarios were envisaged: one assuming a sensitivity of the necropsic examination equal to 1 and one assuming the specificity of the coprology equal to 1. Whatever the scenarios, each test presented good estimated parameters, always superior to 0.9. A significant relationship was clearly established between epg counts and parasites burden: more than 100 epg indicated the presence of more than 100 adult paramphistomes in rumen and/or reticulum.

Downregulation of MHC class I molecules is a strategy developed by some viruses to escape cellular immune responses. Myxoma virus (MV), a poxvirus causing rabbit myxomatosis, encodes MV-LAP that is known to increase MHC-I endocytosis and degradation through a C4HC3 motif critical for an E3 ubiquitin ligase activity. Here, we performed a functional mapping of MV-LAP and showed that not only the C4HC3 motif is necessary for a marked downregulation of MHC-I but also a conserved region in the C-terminal part of the protein. We also showed that the putative transmembrane domains are responsible for a specific subcellular localization of the protein: they retain MV-LAP in the ER in transfected cells and in the endolysosomal compartments in infected cells. We observed that a specific MV infection context is necessary for a fully efficient downregulation of MHC-I. Our data suggest that the functionality of viral LAP factors, inherited by herpes- and poxviruses from mammalian cells, is more complex than anticipated.

Alcoholic extracts of four tropical plants (Zanthoxylum zanthoxyloides, Newbouldia laevis, Morinda lucida and Carica papaya) were screened in vitro for potential anti-parasitic effects against eggs, infective larvae and adult Haemonchus contortus. Significant effects were obtained with all four plants but differences were observed depending on the parasitic stage. The effects of the four plant extracts were similar on egg hatching and were dose dependent. In contrast, no dose-response relationship was found for infective larvae and adult worms, although more potent effects were usually observed with the highest concentrations. Using a larval inhibition migration test, extracts of fagara (Z. zanthoxyloides) were found to be less active against Haemonchus infective larvae than were the other plants. N. laevis was found to be highly and rapidly effective against adult worms. Overall, these in vitro results suggest that these four plants, traditionally used by small farmers in Western Africa, do possess anti-parasitic properties. These effects remain to be confirmed through in vivo studies.

The cytolethal distending toxins (CDT) are responsible for the mitosis block at G2/M and the cycle arrest of cells in culture. Escherichia coli isolated from humans and animals with intestinal and extra-intestinal diseases can be positive for the production of a CDT-like cytopathic effect or for the presence of cdt-related genes. The purpose of this study was to compare the prevalence and the identity of cdt-related sequences in necrotoxigenic E. coli (NTEC). A collection of 98 bovine type 2 NTEC (NTEC2) and 45 bovine, 20 canine, 3 feline, 65 human and 129 porcine type 1 NTEC (NTEC1) isolates was studied by colony hybridisation and PCR assays specific for the cdtB genes encoding the B sub-unit of the CDT-I, CDT-II, CDT-III and CDT-IV toxins produced by E. coli. cdtB-III sequences were frequent amongst bovine NTEC2, since 83% of these isolates were positive by colony hybridisation and/or PCR, whereas cdtB-related sequences were rare amongst NTEC1, since only 2 bovine (4%), 3 canine (15%), 10 human (15%) and 13 porcine (10%) of these isolates were positive. The 28 probe-positive NTEC1 harboured cdtB-IV sequences (13 isolates), cdtB-I sequences (10 isolates), or still unidentified cdt-related sequences (5 isolates). After comparison with previously published and unpublished results of phenotypic assay on cell cultures, existence of other cdt-related sequences is suggested amongst NTEC1. The differences between NTEC1 and NTEC2 in their CDT profiles may have implication for the pathogenesis of those two classes of pathogenic E. coli.

The sheep bot fly, Oestrus ovis, is a very common myiasis of nasal and sinus cavities of sheep and goats causing severe welfare and production implications. As the viability of O. ovis adult flies strictly depends on larval abilities to assimilate and to stock nutrients from the host, it was necessary to investigate proteolytic activities in larval excretory/secretory products (ESP). ESP of O. ovis larvae degrade mucosal and plasmatic components such as mucin, albumin or immunoglobulin G. A preliminary biochemical characterization, using substrate gel analysis and inhibitor sensitivity, demonstrated the presence of at least six major serine proteases (molecular weights from 20 to 100 kDa), mainly trypsin-like, secreted in the digestive tube of larvae. Their involvement in larval trophic activity and evasion from the host immune response is further discussed as O. ovis excretory/secretory serine proteases could represent potential vaccinal targets.

International audience