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Giardia intestinalis is a flagellated protozoan responsible for giardiosis (also called giardiasis in humans), the most prevalent and widespread parasitic infection in humans and mammals worldwide. The intestinal microbiota is highly diverse and any alteration in its composition may impact on the health of the host. While studies on the mouse model of giardiosis described the role of the gut microbiota in host susceptibility to infection by the parasite, little is known about the gut microbiota during natural infections in dogs and particularly in puppies. In this study, we monitored naturally G. intestinalis-infected puppies for 3 months and quantified cyst excretion every 2 weeks. All puppies remained subclinically infected during the sampling period as confirmed by fecal examination. In parallel, we performed 16S Illumina sequencing of fecal samples from the different time points to assess the impact of G. intestinalis infection on gut microbiota development of the puppies, as well as gut health markers of immunity such as fecal IgA and calprotectin. Sequencing results revealed that the canine fecal microbiota of Giardia-infected puppies becomes more complex and less diverse with increasing age. In addition, significant differences in the structure of the microbiota were observed between puppies with high and low Giardia cyst excretion. Chronic subclinical G. intestinalis infection appears to be associated with some detrimental structural changes in the gut microbiota. G. intestinalis-associated dysbiosis is characterized by an enrichment of facultative anaerobic, mucus-degrading, pro-inflammatory species and opportunistic pathogens, as well as a reduction of Lactobacillus johnsonii at specific time points. Calprotectin levels increased with age, suggesting the establishment of chronic low-grade inflammation in puppies. Further work is needed to demonstrate whether these alterations in the canine gut microbiota could lead to a dysbiosis-related disease, such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD).

Consumption of raw or undercooked meat containing Toxoplasma gondii tissue cysts is one of the main sources of infection for humans worldwide. Among the various species intended for human consumption, sheep appear to be a high risk for human infection. The present study focused on the detailed anatomical distribution of Toxoplasma gondii in naturally and experimentally infected lambs using fresh and frozen samples of various pieces of meat, from a public health perspective. The first objective was to rank the edible parts intended for human consumption according to the detectable parasite burden by real-time PCR targeting the 529-bp repeated element. The second objective was to evaluate the impact of freezing by comparing the detection efficiency of the quantitative PCR between fresh and frozen tissues, as imports of lamb carcasses/cuts may arrive frozen or chilled. The highest estimated parasite loads were observed in skeletal muscles, and more particularly in edible portions such as quadriceps femoris muscle, intercostal muscles, deltoid muscle and diaphragm, with a significant difference in detectable parasite burden between fresh and frozen samples (p 0.0001) or natural and experimental infection (p 0.0001). Thoracic and pelvic limbs (3278-1048 parasites/g muscle) were ranked at the top of the list. Toxoplasma gondii DNA was detected in all the edible parts of lamb studied. These results suggest that lamb meat represents a risk for consumers. Further investigations are needed in order to confirm these differences in larger numbers of animals and in different breeds.Distribution anatomique de Toxoplasma gondii chez des agneaux infectés naturellement et expérimentalement.La consommation de viande crue ou insuffisamment cuite contenant des kystes tissulaires de Toxoplasma gondii est l’une des principales sources d’infection pour l’homme dans le monde. Parmi les différentes espèces destinées à la consommation humaine, le mouton apparaît à haut risque d’infection humaine. La présente étude s’est concentrée sur une distribution anatomique détaillée de Toxoplasma gondii chez des agneaux infectés naturellement et expérimentalement à l’aide d’échantillons frais et congelés de divers morceaux de viande, du point de vue de la santé publique. Classer les parties comestibles destinées à la consommation humaine, selon la charge parasitaire détectable par une PCR en temps réel ciblant l’élément répété de 529 pb était un premier objectif. Un second objectif était d’évaluer l’impact de la congélation en comparant l’efficacité de détection de la PCR quantitative entre les tissus frais et congelés, car les importations de carcasses/coupes d’agneau peuvent arriver congelées ou réfrigérées. Les charges parasitaires estimées les plus élevées ont été observées dans les muscles squelettiques et plus particulièrement dans les parties comestibles telles que le quadriceps fémoral, les muscles intercostaux, le deltoïde et le diaphragme avec une différence significative de charge parasitaire détectable entre les échantillons frais et congelés (p 0,0001) ou l’infection naturelle et expérimentale (p 0,0001). Les membres thoraciques et pelviens (3278 à 1048 parasites/g de muscle) ont été classés en tête de liste. L’ADN de T. gondii a été détecté dans toutes les parties comestibles étudiées de l’agneau. Ces résultats suggèrent que l’agneau représente un risque pour les consommateurs. Des investigations supplémentaires doivent être effectuées afin de confirmer les différences mentionnées ci-dessus chez plus d’animaux et dans différentes races.

International audience; To date, no information is available about the presence of Cryptosporidium spp. in French sheep, nor their potential role as zoonotic reservoirs. A total of 23 fecal samples were collected from diarrheic lambs (< 11 days old) from seven randomly selected farms. Cryptosporidium-oocysts were detected microscopically with Direct Immunofluorescence Assays (DFA) in 23/23 (100%) of fecal samples. PCR-RFLP of the 18S rRNA gene was used to determine species in all samples, and only Cryptosporidium parvum was identified. Isolates were subtyped by sequencing the 60 kDa glycoprotein (gp60) gene. Two zoonotic subtypes within the IIa subtype family were identified, including IIaA15G2R1 (22/23) and IIaA16G3R1 (1/23). This study reports for the first time the identification and genotyping of zoonotic C. parvum subtypes from lambs in France. Sheep could thus play an important role as potential reservoirs for this zoonotic protist.

Cryptosporidium is an obligate intracellular protist parasite infecting a wide range of vertebrate hosts and causes significant intestinal disease in both animals and humans, as some species are zoonotic. Cattle and especially calves have been identified as one of the most common reservoirs of this protist. However, little is known about the genetics of Cryptosporidium in calves in some regions of France. The aim of this study was to detect and isolate Cryptosporidium spp. in faecal samples from naturally infected pre-weaned calves (≤45 days-old) in France. A total of 35 diarrhoeic pre-weaned calf faecal samples were collected from 26 dairy cattle farms in six departments (French administrative provinces). Cryptosporidium presence was established by microscopically screening samples for oocystes with an immunofluorescent (DFA) staining method. DFA-positive samples were then analysed by PCR-RFLP and 18S rRNA gene sequencing to determine species. Cryptosporidium parvum-positive samples were subtyped via nested PCR analysis of a partial fragment of the 60 kDa glycoprotein (gp60) gene product. Data were then integrated into phylogenetic tree analysis. DFA revealed the presence of Cryptosporidium oocysts in 31 out of 35 (88%) samples. Combined with 18S rRNA gene analysis results, C. parvum was detected in 30 samples. Subtyping analysis in 27/30 samples (90%) of the C. parvum isolates revealed two zoonotic subtype families, IIa (24/27) and IId (3/27). Four subtypes were recognised within the subtype family IIa, including the hypertransmissible IIaA15G2R1 subtype that is the most frequently reported worldwide (21/27), IIaA17G3R1 (1/27), IIaA17G1R1 (1/27), and IIaA19G1R1 (1/27). Two subtypes were recognised within the IId subtype family including IIdA22G1 (2/27) and IIdA27G1 (1/27). These findings illustrate the high occurrence of Cryptosporidium in calves in dairy herds and increase the diversity of molecularly characterised C. parvum isolates with the first description of IIaA17G3R1, IIaA19G1R1, and IId subtypes in France. The presence of zoonotic C. parvum subtype families (IIa, IId) in this study suggests that pre-weaned calves are likely to be a significant reservoir of zoonotic C. parvum, and highlights the importance of animal to human cryptosporidiosis transmission risk. Further molecular studies in calves and small ruminants from other French regions are required to better understand the epidemiology of cryptosporidiosis in France., Highlights • Faecal samples from pre-weaned diarrheal calves were analysed • Cryptosporidium spp. was detected in 30 samples out of 35. • C. parvum was the only species identified • Two zoonotic subtype families were identified: IIa and IId • The hyper-transmissible IIaA15G2R1 was the dominant C. parvum subtype

Giardia duodenalis (syn. G. lamblia, G. intestinalis) is the protozoan parasite responsible for giardiasis, the most common and widely spread intestinal parasitic disease worldwide, affecting both humans and animals. After cysts ingestion (through either contaminated food or water), Giardia excysts in the upper intestinal tract to release replicating trophozoites that are responsible for the production of symptoms. In the gut, Giardia cohabits with the host's microbiota, and several studies have revealed the importance of this gut ecosystem and/or some probiotic bacteria in providing protection against G. duodenalis infection through mechanisms that remain incompletely understood. Recent findings suggest that Bile-Salt-Hydrolase (BSH)-like activities from the probiotic strain of Lactobacillus johnsonii La1 may contribute to the anti-giardial activity displayed by this strain. Here, we cloned and expressed each of the three bsh genes present in the L. johnsonii La1 genome to study their enzymatic and biological properties. While BSH47 and BSH56 were expressed as recombinant active enzymes, no significant enzymatic activity was detected with BSH12. In vitro assays allowed determining the substrate specificities of both BSH47 and BSH56, which were different. Modeling of these BSHs indicated a strong conservation of their 3-D structures despite low conservation of their primary structures. Both recombinant enzymes were able to mediate anti-giardial biological activity against Giardia trophozoites in vitro. Moreover, BSH47 exerted significant anti-giardial effects when tested in a murine model of giardiasis. These results shed new light on the mechanism, whereby active BSH derived from the probiotic strain Lactobacillus johnsonii La1 may yield anti-giardial effects in vitro and in vivo. These findings pave the way toward novel approaches for the treatment of this widely spread but neglected infectious disease, both in human and in veterinary medicine.

In France, the consumption of cattle and sheep meat appears to be a risk factor for infection of pregnant women with Toxoplasma gondii. Several nation-wide surveys in France have investigated the prevalence of T. gondii in sheep and pig meat, but little is known at present about the prevalence of the parasite in beef. The main objective of the present cross-sectional survey was to estimate the seroprevalence of T. gondii infection in beef consumed in France. A secondary objective was to attempt to isolate T. gondii from cattle tissues and to study the geographical and age variations of this seroprevalence. The overall estimate of seroprevalence of T. gondii in bovine carcasses (n = 2912), for a threshold of 1:6 was 17.38%. A strong age effect was observed (p 0.0001) with a seroprevalence of 5.34% for calves (8 months) and 23.12% for adults (8 months). Seroprevalence estimates given by area of birth and area of slaughtering for adults showed that the areas with the highest seroprevalence were not the same between these two variables. Only two strains, corresponding to genotype II, were isolated from heart samples, indicating that there is a limited risk of human infection with T. gondii, which needs to be correlated with the food habit of consuming raw or undercook (bleu or saignant) beef. However, new questions have emerged, especially concerning the isolation of parasites from beef and the precise role of bovines, generally described as poor hosts for T. gondii, in human infection.Toxoplasma gondii dans la viande bovine consommée en France : variation régionale de la séroprévalence et isolement de parasites.En France, la consommation de viande bovine et ovine apparaît comme un facteur de risque pour la contamination des femmes enceintes par Toxoplasma gondii. Plusieurs enquêtes nationales ont été réalisées afin de déterminer le niveau de contamination par T. gondii de la viande ovine et porcine, en France, mais très peu est encore connu quant à la prévalence du parasite dans la viande bovine. La présente enquête transversale avait pour objectif principal d’estimer la séroprévalence de l’infection à T. gondii dans la viande bovine consommée en France, ainsi que d’isoler T. gondii à partir de tissus de bovins et d’étudier, à titre d’objectif secondaire, les variations géographiques et d’âge de cette prévalence. L’estimation globale de la séroprévalence de T. gondii dans les carcasses de bovins (n = 2912) était de 17,38 % (pour un seuil de dilution à 1:6). Un effet significatif de l’âge a été observé (p 0,0001) avec une séroprévalence de 5,34 % pour les veaux (8 mois) et de 23,12 % pour les adultes (8 mois). Les estimations de séroprévalence données par zone de naissance et par zone d’abattage pour les adultes montrent que les zones de séroprévalence les plus élevées n’étaient pas les mêmes pour ces deux variables. Seulement deux souches, de génotype II, ont été isolées à partir d’échantillons de cœurs, soulignant que le risque d’infection humaine est limité, mais doit être corrélé avec les habitudes de consommation alimentaire de la viande bovine peu/pas cuite (bleu ou saignante). Cependant, de nouvelles questions se posent, notamment en ce qui concerne l’isolement du parasite à partir de la viande bovine, ainsi que le rôle précis des bovins, généralement décrits comme des hôtes médiocres pour T. gondii, dans la contamination humaine.

The PrP gene polymorphisms at codons 142 (I/M), 154 (R/H), 211 (R/Q), 222 (Q/K) and 240 (S/P) and their association with susceptibility to classical scrapie infection were investigated in five French goat herds displaying a high disease prevalence (>10 %). On the basis of PrPSc detection in the central nervous system and in various lymphoid tissues, 301 of 1343 goats were found to be scrapie infected. The statistical analyses indicated that while P240 mutation had no direct impact on scrapie infection risk, the H154, Q211 and K222 mutations were associated with high resistance to scrapie. The M142 mutated allele was associated with a limited protection level against the disease. These results further reinforce the view that, like in sheep, the control and eradication of classical scrapie through the selection of certain PrP alleles could be envisaged in commercial goat population.

Besides cysticercosis, scarce information is available on the other meat-borne zoonotic parasitoses in the domestic ani¬mal population of Madagascar. Trichinella is an intracellular parasitic nematode of mammalian skeletal muscle, causing a serious zoonotic disease. Trichinella is transmitted to humans by consumption of raw or undercooked meat from pig, wild boar and other sensitive species (1). Toxoplasma gondii is a protozoan parasite that can probably infect all warm-blooded animals (mammals and birds) and humans. Humans become infected postnatal by ingesting tissue cysts from undercooked meat (various species), consuming food or drink contaminated with oocysts, or by accidentally ingesting oocysts from the envi¬ronment (2). The present study aimed at investigating the extent of two major parasitic diseases, namely toxoplasmosis and trich¬inellosis, within the Malagasy pig population. Two hundred and fifty pig serum samples were collected dur¬ing 2010 in the four major slaughterhouses of Antananarivo, the Malagasy capital. Sampled pigs were raised in 11 different regions (of a total of 22 regions) and transported by traders before slaughtering. Samples were stored at -80°C and sent for analysis to the Agence nationale de securite sanitaire de l'alimentation, de l'environnement et du travail (ANSES, Maisons-Alfort, France). Serological investigations were conducted for both pathogens using ELISA technique with commercial test kits: ID Screen® Toxoplasmosis Indirect ELISA kit (IdVet, France) and PrioCHECK® Trichinella Ab (Prionics, Switzerland), according to the manufacturer's instructions. Results on seroprevalence of T. gondii in pigs confirm that the zoonotic parasite is present in Madagascar. Preliminary results show a seroprevalence of 22.8% (57/250) for toxoplasmosis. All regions are endemic for toxoplasmosis with a frequency of posi-tive pigs ranging from 12% (n = 8) in the southern province of Toliara, to 21% in Antananarivo (n = 69) or Fianarantsoa (n = 79) in central uplands, and up to 33% (n = 69) in Mahajanga in the coastal northwestern region; no region of the island can be considered free of toxoplasmosis. No correlations were found with sex, breed or age of pigs. From a public health perspective these results emphasize the need to inform the public on the importance of proper meat handling and preparation. Regarding Trichinella, two pigs presented positive values by ELISA based on excretory/secretory antigens but those results were not confirmed in western blot. Even if the serological test for the detection of Trichinella provides a high degree of sensitiv¬ity and specificity, false negative results occur during the early stages of infection, especially for light to moderate infection. Further investigations correlating serology and muscle analy¬sis need to be conducted to conclude on Trichinella status in Madagascar. National field investigations in pig and human populations will have to be carried out to confirm the present results as well as to correlate the observed prevalence with on-farm risk factors, and with the transmission of trichinellosis and toxoplasmosis to Malagasy consumers, especially to pregnant women. (Resume d'auteur)

SUMMARYKnowledge of the factors affecting the presence of Toxoplasma gondii in wildlife is limited. Here we analyse which local landscape characteristics are associated with the presence of toxoplasmosis in wild boar, Sus scrofa, on the island of Corsica, France. Meat juice samples from 1399 wild boars collected during two hunting seasons were tested for T. gondii antibodies using the modified agglutination test (titre 1:4). The overall seroprevalence was 0·55 (95% CI 0·50–0·59) for the first year and 0·33 (95% CI 0·29–0·35) for the second year. Seroprevalence varied according to age and county. At the county level, seropositivity in adults was related to farm density during year 1, and to habitat fragmentation, farm density and altitude during year 2. The exposure of wild boar to T. gondii is thus variable according to landscape characteristics and probably results in a variable risk of transmission of toxoplasmosis to humans.