Treatment and prevention of cryptosporidiosis in young ruminants (goat kids) : the interest of natural polysaccharides

La cryptosporidiose est une parasitose cosmopolite affectant de nombreuses espèces animales. Elle provoque des diarrhées néonatales chez les ruminants occasionnant des pertes économiques dans les élevages. Le principal protozoaire responsable est Cryptosporidium parvum. Aucun traitement pleinement efficace n’est disponible pour lutter contre la cryptosporidiose. Dans cet article, nous présentons une nouvelle approche thérapeutique basée sur l’utilisation des polysaccharides naturels tels que le chitosan. Dans notre travail, à l’aide de 2 modèles in vitro de cellules intestinales (HCT-8 et Caco-2) nous avons montré que le chitosan était efficace pour réduire le nombre d’oocystes de C. parvum. Une autre étude a été également menée afin de confirmer ces effets inhibiteurs sur des chevreaux infectés expérimentalement. Les résultats montrent, chez les animaux infectés et traités avec un produit (OptisafR) contenant du chitosan, une baisse de l’excrétion fécale des oocystes de C. parvum et de la sévérité de la diarrhée.Cryptosporidiosis is a cosmopolitan parasitosis affecting many animal species. It causes neonatal diarrhea in ruminants causing economic losses in farms. The main protozoan responsible is Cryptosporidium parvum. No fully effective treatment is available to control cryptosporidiosis. In this article, we present a new therapeutic approach based on the use of natural polysaccharides (chitosan). In our work, using 2 in vitro models of intestinal cells (HCT-8 and Caco-2), we have shown that Chitosan is effective in reducing the number of oocysts of C. parvum. Another study was also conducted to confirm these inhibitory effects on experimentally infected goat kids. The results show, in infected animals treated with a product containing Chitosan, a decrease in faecal excretion of C. parvum oocysts and the severity of diarrhea

Diagnostic tests for human and animal prion diseases

The potential existence of clinically silent cases of bovine spongiform encephalopathy (BSE) among cattle, and of humans incubating the new variant Creutzfeldt-Jakob disease (nvCJD) is still a major public health concern. Therefore, the development of screening tests for transmissible subacute spongiform encephalopathies (TSSE) in man and animals remains a priority. In the first part of this paper, we review the main methods used to diagnose generally clinical TSSE, such as brain imaging, electroencephalogram (EEG) analysis, and cerebrospinal fluid (CSF) analysis. In the second part, we present the post-mortem tests used to confirm a TSSE diagnosis, such as inoculation to laboratory animals, histological examination, and identification of abnormal prion protein (PrPres) using biochemical methods. Finally, the third part presents so-called rapid tests (Prionics, Bio-rad, Enfer), validated by the European Commission (EC) for post-slaughter BSE diagnosis in cattle. Now used on a large scale in Europe, these tests have helped assess the extent of the epizooty and eliminate from the food chain animals presenting a risk for human consumption. Since 2002, they have been used for the post-slaughter diagnosis of scrapie in small ruminants. New tests have recently been evaluated by the EC, but it is too soon to predict their role in the field.L'existence potentielle de bovins en phase de latence cliniquement silencieuse d'encéphalopathie spongiforme bovine (ESB) et d'individus en période d'incubation de la nouvelle variante de la maladie de Creutzfeldt-Jakob représente constamment un grand risque pour la santé publique. Par conséquent, le développement de tests de dépistage des encéphalopathies spongiformes subaiguës transmissibles (ESST) humaines et animales constitue toujours une priorité. Dans la première partie de cet article, sont décrites les principales méthodes d'orientation permettant d'aider au diagnostic d'une ESST le plus souvent clinique, comme l'imagerie médicale cérébrale, l'analyse de l'électroencéphalogramme (EEG) et l'examen du liquide céphalo-rachidien. Dans la deuxième partie, sont présentés les tests de confirmation post mortem du diagnostic des ESST, comme l'inoculation à l'animal de laboratoire, l'examen histologique et la recherche de la PrPres par des méthodes biochimiques. La troisième partie est consacrée aux tests dits « rapides » (Prionics, Bio-rad, Enfer), validés en 1999 par la Commission Européenne (CE), pour le diagnostic post mortem de l'ESB à l'abattoir chez les bovins. Utilisés à grande échelle en Europe, ils ont permis de préciser l'étendue réelle de l'épizootie et d'éliminer efficacement de la chaîne alimentaire les animaux présentant un risque pour l'homme. Depuis 2002, ils sont également utilisés pour le diagnostic post mortem des petits ruminants. De nouveaux tests ont été récemment évalués par la CE, mais il est trop tôt pour évaluer la place qu'ils tiendront sur le terrain

Mes conseils pour réussir sa carrière scientifique Mohamed Gharbi Editeur Publipresse, Tunis, 2019

Adjou Karim Tarik. Mes conseils pour réussir sa carrière scientifique Mohamed Gharbi Editeur Publipresse, Tunis, 2019. In: Bulletin de l'Académie Vétérinaire de France tome 174, 2021. pp. 354-355

Veterinary and public health importance of cryptosporidiosis in Algeria: an update and new insights

Cryptosporidiosis is a parasitic zoonosis caused by several species from the Cryptosporidium genus. This disease affects all vertebrates, including humans, and is most frequently clinically expressed by diarrheal enteritis. Little data has been published on either human or animal cryptosporidiosis in Algeria. The objective of this review is to discuss all studies conducted to date in Algeria, and to place them into perspective in a global context. To date, Cryptosporidium. spp has been described in several domestic or breeding animals in Algeria: rabbit, horse, sheep, donkey, chicken, turkey, camel, as well as some wild or captive birds (ostrich, wild mallard, graylag goose). The few molecular studies available have identified 12 species (C. parvum, C. hominis, C. erinacei, C. cuniculus, C. meleagridis, C. ubiquitum, C. andersoni, C. muris, C. bovis, C. ryanae, C. xiaoi, C. baileyi) including 8 zoonotic Cryptosporidium species/subtypes. The single human study in Algeria reported a very low Cryptosporidium prevalence (0.4%) in humans, but this is very likely linked to disease under diagnosis. The detection of zoonotic species or subtypes in animals from Algeria highlights the potential risk for zoonotic transmission. Further molecular studies are needed to determine the circulating anthroponotic or zoonotic species and subtypes, in order to implement effective preventive strategies. Improving collaborations between veterinarians and medical professionals aligned with the "one world-one health" program is absolutely necessary to trace the history and improve prevention of cryptosporidiosis in Algeria

Epidémiologie et aspects cliniques des encéphalopathies spongiformes subaiguës transmissibles (ESST) animales

Transmissible spongiform subacute encephalopathies (TSSE) occurring under natural conditions include mainly scrapie in sheep and goat, chronic wasting disease (CWD) in Cervidae, and bovine spongiform encephalopathy (BSE). The precautionary measures taken against BSE are now bearing fruit, as case numbers decrease every year, particuiarly in France. Moreover numerous studies have shown the interest of clinical examination of cattle to detect BSE in the field. In the other ruminants, chronic wasting disease (CWD) remains a matter of concern in North America, while new worries have appeared on scrapie in small ruminants : a BSE-like strain has been discovered in a case of goat scrapie in France, genetic selection to fight sheep scrapie is being questioned (emergence of “atypical cases” in “resistant” animals, especially the Nor98 strain of scrapie). These data demonstrate the interest of active monitoring of scrapie of small ruminants in Europe.Les encéphalopathies spongiformes subaiguës transmissibles (ESST) animales comprennent principalement, dans les conditions naturelles, la tremblante des petits ruminants, la maladie du dépérissement chronique des cervidés (MDCC) et l’encéphalopathie spongiforme bovine (ESB). On observe actuellement les résultats de l’efficacité des mesures de précaution concernant l’ESB avec une diminution du nombre des cas chaque année, en particulier en France. Par ailleurs, de nombreuses études démontrent l''intérêt de l''examen clinique des bovins pour la détection de l''ESB. Chez les autres ruminants, la maladie du dépérissement chronique des cervidés (MDCC) demeure une préoccupation en Amérique du Nord, alors que de nouvelles inquiétudes apparaissent dans le cas de la tremblante des petits ruminants : découverte d’une souche de type ESB dans un cas de tremblante caprine en France, remise en question de la sélection génétique dans la lutte contre la tremblante ovine (apparition de «cas atypiques» chez des animaux «résistants», en particulier avec la souche tremblante Nor 98). Ces données démontrent l’intérêt d’une surveillance active de la tremblante des petits ruminants en Europe.Couquet C., Allix S., Brugère-Picoux Jeanne, Adjou Karim Tarik, El Hachimi Hamid, Brugère Henri. Epidémiologie et aspects cliniques des encéphalopathies spongiformes subaiguës transmissibles (ESST) animales. In: Bulletin de l'Académie Vétérinaire de France tome 158 n°4, 2005. pp. 423-428

Cryptosporidium parvum-infected neonatal mice show gut microbiota remodelling using high-throughput sequencing analysis: preliminary results

International audienceBackground During the last decade, the scientific community has begun to investigate the composition and role of gut microbiota in normal health and disease. These studies have provided crucial information on the relationship between gut microflora composition and intestinal parasitic infection, and have demonstrated that many enteric pathogen infections are associated with altered gut microflora composition. In this study, we investigated the effects of Cryptosporidium parvum infection (zoonotic protozoan affecting a large range of vertebrates) on both qualitative and quantitative composition of gut microbiota in a CD-1 neonatal mouse model. Methods 5-day-old neonate mice were experimentally infected with 105Cryptosporidium parvum Iowa oocysts by oesophageal gavage. The intestinal microbiota of both infected (Cp+) and uninfected (Cp−) mice groups was examined by high-throughput sequencing of the bacterial 16S rDNA gene V3–V4 hypervariable region. Results The most consistent change in the microbiota composition of Cp+ mice was the increased proportion of bacterial communities belonging to the Phylum Bacteroidetes. In contrast, the microbiota of Cp− mice was associated with increased proportions of several Firmicutes and Actinobacteria phyla members. Conclusion For the first time, our study provides evidence of an association between cryptosporidial infection and gut dysbiosis, thus contributing valuable knowledge to the as-yet little-explored field of Cryptosporidium–microbiota interactions in a neonatal mouse model

First identification of Cryptosporidium parvum zoonotic subtype IIaA15G2R1 in diarrheal lambs in France

International audienceTo 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

Molecular characterization of Cryptosporidium isolates from diarrheal dairy calves in France

International audienceCryptosporidium 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 Ha, 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 (Ha, 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

Molecular characterization of zoonotic Cryptosporidium spp. and Giardia duodenalis pathogens in Algerian sheep

International audienceLittle is known about the presence of Cryptosporidium spp. and Giardia duodenalis in Algerian sheep, nor their potential role as zoonotic reservoirs. This study aimed to investigate the occurrence and distribution of these two protists in lambs. A total of 83 fecal samples were collected from lambs (< 40 days old) from 14 different farms. Samples were screened for Cryptosporidium spp. and Giardia duodenalis presence using immunofluorescent techniques (IF). Nested PCR of the small subunit ribosomal RNA (rRNA) gene, followed by restriction fragment length polymorphism (PCR-RFLP) and sequence analyses were used to identify Cryptosporidium species. C. parvum was further subtyped by sequencing the highly polymorphic 60 kDa glycoprotein (gp60) gene. For G. duodenalis, nested PCR of the glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) genes was performed and then PCR-RFLP was used to identify G. duodenalis assemblages. Cryptosporidium oocysts and Giardia cysts were detected in 36/83 (43%) and 23/83 (28%) of fecal samples, respectively. Of the 21/36 (58%) Cryptosporidium samples that were positive with IF, 16/21 (76%) were identified as C. parvum, and 5/21 (24%) as C. ubiquitum. From 15C. parvum isolates, 2 subtypes were identified within the Ha subtype family, including IIaA21G2R1 (3/15) and IIaA13G2R1 (1/15), while IIdA16G1 (11/15) was the only subtype identified from the lid subtype family. Of the 16/23 (69%) G. duodenalis IF-positive samples, the most frequent assemblage was ruminant-specific assemblage E (10/16), followed by assemblage D (4/16), and A + E mixed assemblages (2/16). This study is the first to identify and genotype both Cryptosporidium spp. and Giardia duodenalis in Algerian lambs, and is also the first to describe G. duodenalis assemblage D in small ruminants. The presence of zoonotic C. parvum subtype families (IIa, IId), C. ubiquitum, as well as G. duodenalis assemblage A + E, indicates that sheep could play an important role as a potential reservoir for protists

Cryptosporidium parvum Infection Depletes Butyrate Producer Bacteria in Goat Kid Microbiome

Cryptosporidium parvum is an important apicomplexan parasite infecting ruminants and humans. We characterized the impact of C. parvum infection on the goat kid microbiome. C. parvum was orally administered to parasite-naïve goats, and infection was monitored for 26 days in fecal samples using immunofluorescence assay and qPCR tests. Age-matched goats served as uninfected controls. A reduction in body weight gain, diarrhea, and dehydration were observed in infected goats compared to the uninfected controls. Infection decreased the bacterial diversity 5 days post-infection (dpi), but this parameter recovered at 15 dpi. The infection altered the relative abundance of several taxa. A total of 38 taxa displayed significant differences in abundance between control and infected goats at both 5 and 15 dpi. Co-occurrence network analysis revealed that the infection resulted in a differential pattern of taxa interactions and that C. parvum infection increased the relative abundance of specific taxa. The 16S data set was used for metagenome predictions using the software package PICRUSt2. As many as 34 and 40 MetaCyc pathways (from 387 total) were significantly affected by the infection at 5 and 15 dpi, respectively. Notably, C. parvum decreased the abundance of butyrate-producing pathways in bacteria. Low levels of butyrate may increase mucosal inflammation and tissue repair. Our results suggest that the gut inflammation induced by C. parvum infection is associated with the reduction of butyrate-producing bacteria. This insight could be the basis for the development of novel control strategies to improve animal health