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Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are significant parasitic gastrointestinal pathogens with global distribution in humans and domestic animals, including calves. The main symptoms of calf infection are severe diarrhea, dehydration, growth retardation, and sometimes even death. To date, there has been limited information on the prevalence of Cryptosporidium spp., G. duodenalis, and E. bieneusi infections in calves in Ningxia, China, especially between diarrheic and non-diarrheic calves. A total of 438 fecal samples were collected from diarrheic (201) and non-diarrheic (237) calves in Ningxia. PCR and DNA sequencing were used to find the prevalence of Cryptosporidium spp. at 46.8% (205/438), G. duodenalis at 16.9% (74/438), and E. bieneusi at 10.0% (44/438). The prevalence of Cryptosporidium spp. infection in diarrheic and non-diarrheic calves was 54.0% (128/237) and 38.3% (77/201), respectively, and statistical analysis showed a positive correlation between the prevalence of Cryptosporidium spp. infection and calf diarrhea (p < 0.01). However, in this study, there was no statistical correlation between the prevalence of G. duodenalis infection as well as E. bieneusi infection and calf diarrhea (p > 0.05). Furthermore, four known Cryptosporidium species were successfully identified by comparing them with SSU rRNA gene sequences, including C. parvum, C. bovis, C. ryanae, and C. andersoni. In addition, all 74 G. duodenalis-positive samples were identified as assemblage E by comparative analysis of bg gene sequences. Among the 44 E. bieneusi-positive samples sequenced in the present study, 4 distinct E. bieneusi genotypes were successfully identified by comparative analysis of ITS sequences, including 3 known genotypes (J, BEB4, and N) and 1 novel genotype, the latter of which was identified and designated as NX1. These findings indicated that the high genetic diversity and complex population structures of Cryptosporidium spp., G. duodenalis, and E. bieneusi in Ningxia diarrhea calves and non-diarrhea calves, which provide new data for understanding the epidemiological status of Cryptosporidium spp., G. duodenalis, and E. bieneusi in Ningxia calves.

(1) Intestinal microbial parasites are major contributors to the global burden of gastrointestinal disease. Such infections are mainly caused by Cryptosporidium, Giardia duodenalis, and Entamoeba histolytica. These parasites are transmitted either directly or indirectly through oral–fecal routes. Previous reports suggested that camels could play a role in the zoonotic transmission of various clinically and veterinary important intestinal parasites, however, limited data are available on intestinal infections of camels, particularly on a molecular level. We aimed to explore the occurrence of these three parasites in camels (Camelus dromedarius) in Algeria. (2) A total of 68 samples—63 stool samples from camels and five from the environment—were collected from two desert regions in Algeria and analyzed using PCR and qPCR methods. (3) Overall, 7% of the camels tested positive for zoonotic subtypes of Cryptosporidium spp., while 16% of the camels tested positive for G. duodenalis. Two environmental samples also tested positive for G. duodenalis. None of the samples were positive for Entamoeba histolytica. (4) Our results provide one of the first molecular-based identification of these gut parasites in dromedary camels in Algeria. The presence of G. duodenalis in the host and the environment unveils, in part, the circulation route of this parasite. Our results will spearhead further investigations into the prevalence and epidemiology of gut parasites in hoofed animals and raise questions concerning their role in health and disease in the area.

Enteropathogenic parasites and viruses have been frequently reported in swine and can infect a wide range of mammals, including humans. Among the wide variety of parasites infecting swine, diarrhoeagenic protists are among those that cause significant morbidity. Hepatitis E virus (HEV) has also been reported both in domestic pigs and wild boar and is known to have an important public health significance. These agents share the fecal−oral transmission route, but data on their fecal shedding and circulation pathways are still lacking or incomplete. Hence, the aim of the present study was to characterize the presence of microeukaryotes and HEV in the wild boar of Portugal. Wild boar stool samples (n = 144) were obtained during the official hunting seasons (October to February) in 2018/2019, 2019/2020, and 2021/2022 and tested for Cryptosporidium spp., Balantioides coli, Giardia duodenalis, Blastocystis sp., Enterocytozoon bieneusi and HEV by molecular assays, followed by sequencing and phylogenetic analysis. We have detected Cryptosporidium scrofarum (1.4%, 95% CI: 0.2−4.9), B. coli (14.6%, 95% CI: 9.2−21.4), Blastocystis ST5 (29.2%, 95% CI: 21.9−37.2) and HEV genotype 3 (2.8%, 95% CI: 0.7−6.9; subgenotypes 3e and 3m). Co-infections were observed in thirteen animals where two were positive for both HEV and B. coli, one was positive for both C. scrofarum and Blastocystis ST5, and ten were positive for both B. coli and Blastocystis ST5. Giardia duodenalis and E. bieneusi were not detected in the surveyed wild boar population. As far as we know, this is the first report describing protist infections by Cryptosporidium spp., B. coli, and Blastocystis sp., as well as the first identification of the emerging HEV genotype 3m in wild boar of Portugal. The present work shows that potentially zoonotic protozoa and HEV are circulating in wild boar populations in Portugal. Awareness and epidemic-surveillance network implementation measures targeting wild boar are needed to prevent the spread of these pathogenic agents to humans. This research was funded by Fundação para Ciência e Tecnologia (FCT), grant number 2021.09461.BD. Sí

Cryptosporidium spp., protozoario que pertenece al phylum Aplicomplexa, parasita a hospedadores vertebrados, incluido el hombre. Los individuos infectados por Cryptosporidium spp. pueden presentar un amplio espectro de manifestaciones clínicas dependiendo de la especie del parásito y también del tipo, edad y respuesta inmune del hospedador (Xiao et al., 2004)., Facultad de Ciencias Veterinarias, Facultad de Ciencias Naturales y Museo

Objective:Giardia intestinalis and Cryptosporidium spp. are important zoonotic protozoan parasites that infect humans and various animals. We investigated the occurrence of G. intestinalis and Cryptosporidium spp. infection in cats. To provide data on the zoonotic transmission dynamics of these parasites, genotypes of the detected isolates were investigated through DNA sequence characterization.Methods:A total of 100 fecal samples were collected from cats between June and October 2020 in Kayseri and Samsun provinces. Fecal samples were examined by nested polymerase chain reaction (PCR), targeting the β-giardin gene of G. intestinalis and small subunit (SSU) rRNA gene of Cryptosporidium spp. All PCR products were sequenced for genotyping.Results:Of the samples examined, Giardia intestinalis was determined in 8 samples (8.0%), whereas none of the samples were found positive for Cryptosporidium spp. Sequence analyses of the β-giardin PCR products indicated that all G. intestinalis isolates were classed into the zoonotic assemblage B.Conclusion:This study adds to the current data on the molecular epidemiology of cryptosporidiosis and giardiasis in cats. The findings also highlight the potential risk of cats for public health concerning the zoonotic transmission dynamics of G. intestinalis.

As infeções parasitárias causadas por helmintas intestinais, estão entre as mais prevalentes infeções lentas em humanos no mundo, principalmente nos países em desenvolvimento, incluindo Moçambique e, com as infeções causadas por protozoários intestinais, contribuem significativamente para grande carga de doenças gastrointestinais nestes países, sobretudo nas crianças. Giardia duodenalis e Cryptosporidium spp. são dois organismos protozoários que infetam os humanos e diversas espécies animais e são conhecidos por apresentar um elevado potencial em causar diarreia. Existem em Moçambique alguns estudos sobre a epidemiologia das infeções provocadas por parasitas intestinais, contudo, esta informação é muito fragmentada e escassa sobretudo no que diz respeito à epidemiologia molecular de G. duodenalis e Cryptosporidium spp. Este estudo teve como objetivo geral, determinar a frequência e os fatores relacionados com a infeção por parasitas intestinais (IPI) e caracterizar geneticamente G. duodenalis e Cryptosporidium spp. circulantes em crianças até aos 14 anos de idade com doença diarreica, nas regiões sul, centro e norte de Moçambique. Para o estudo foram analisadas 1424 amostras de fezes diarreicas (do projeto ViNaDia, Moçambique) recrutadas em crianças até 14 anos em seis hospitais públicos das regiões sul, centro e norte de Moçambique. Uma única amostra de fezes foi colhida por criança e examinada por Microscopia Óptica (M.O.) usando a concentração de formol-éter e a técnica de coloração de Ziehl-Neelsen modificada para identificar parasitas intestinais, nomeadamente coccídeos e Cryptosporidium. As características sociodemográficas foram obtidas por meio de questionários. Para caracterização molecular foram utilisadas amostras positivas por M.O. assim como por imunoensaio enzimático (ELISA) (de outro subestudo do projeto ViNaDia). A caracterização genética foi realizada por nested-PCR com alvos nos genes β-giardina de G. duodenlais e ssu rRNA e gp60 de Cryptosporidium spp. Análises uni e bivariadas e regressão logística binária foram realizadas para descrever a população e determinar os fatores de risco. Níveis de significância de 5% foram considerados significativos. Pelo menos uma IPI foi detetada em 19,2% (273/1424) das crianças. Cryptosporidium spp. foi o parasita mais comum (8,1%; 115/1424). Poliparasitismo foi observado em 26,0% (71/273) das crianças estudadas, sendo a coinfeção Ascaris lumbricoides e Trichuris trichiura (26,8%; 19/71) a mais comum. A idade e província foram relacionadas com a presença de IPI (p-valor < 0,05). A maior ocorrência de IPI foi observada na estação das chuvas (outubro a março) com 23,1% (191/828) em relação aos períodos secos (abril a setembro) com 13,6% (80/588) (p-valor < 0,001 ). O subtipo IaA9G3 de C. hominis foi o dominante nas crianças infetadas por Cryptosporidium e o subgenótipo AII de G. duodenalis foi o mais observado (56,6%; 13/23) na população pediátrica moçambicana. Cryptosporidium spp. e a combinação A. lumbricoides/T. trichiura foram os principais parasitas intestinais observados em crianças hospitalizadas com diarreia em Moçambique. Os dados de genotipagem sugerem que as principais vias de transmissão de G. duodenalis e Cryptosporidium em Moçambique são antroponóticas. Parasitic infections caused by intestinal helminths are among the most prevalent sluggish infections in humans in the world, mainly in developing countries, including Mozambique, and with infections caused by intestinal protozoa, they contribute significantly to large burdens of gastrointestinal diseases in these countries, especially in children. Giardia duodenalis and Cryptosporidium spp. are two protozoan organisms that infect humans and several animal species and are known to have a high potential to cause diarrhea. There are some studies in Mozambique on the epidemiology of diseases caused by intestinal parasites; however, this information is very fragmented and scarce regarding the molecular epidemiology of G. duodenalis and Cryptosporidium spp. This study aimed to determine the frequency and factors related to intestinal parasites infection and to characterize genetically G. duodenalis and Cryptosporidium spp. circulating in children up to 14 years of age with diarrheal disease in southern, central and northern Mozambique. For this purpose, 1424 diarrheal stool samples (included in the ViNaDia project, Mozambique) were collected from children up to 14 years old in six public hospitals in the southern, central and northern regions of Mozambique. A single stool sample was collected per child and examined by light microscopy using formalin-ether concentration and modified Ziehl-Neelsen techniques to identify intestinal parasites, namely coccidia and Cryptosporidium. Sociodemographic characteristics were obtained through questionnaires. For molecular characterization positive samples from light microscopy as well as by ELISA (from another ViNaDia sub study) were used. Genetic characterization was performed by nested-PCR targeting β-giardin gene for G. duodenlais and SSUrRNA and gp60 genes for Cryptosporidium spp. Univariate and bivariate analysis and binary logistic regression were performed to describe the population and determine risk factors. Significance levels of 5% were considered significant. A single IPI was detected in 19.2% (273/1424) of children. Cryptosporidium spp. was the most common parasite (8.1%; 115/1424). Polyparasitism was observed in 26.0% (71/273) of the children, with Ascaris lumbricoides and Trichuris trichiura (26.8%; 19/71) being the most common co-infection. Age and province were related to IPI (p-value < 0.05). The highest occurrence of IPI was observed in the wet season (October to March) with 23.1% (191/828) compared to the dry season (April to September) with 13.6% (80/588) (p-value < 0.001). The IbA9G3 subtype of C. hominis was the most dominant in children infected with Cryptosporidium and sub assemblage AII 56.6% (13/23) more frequently observed in children infected with G. duodenalis in the Mozambican pediatric population. Cryptosporidium spp. and the combination A. lumbricoides/T. trichiura were the main intestinal parasites observed in children hospitalized with diarrhea in Mozambique. Genotyping data suggest that the main routes of transmission of G. duodenalis and Cryptosporidium in Mozambique are anthroponotic.

Intestinal parasitic infections (IPIs) are a major cause of morbidity worldwide and have been described as an important public health problem. The present study aimed to determine the un usual parasitic infection and identification of risk factors among 4-12years old school age children residing in lower dir district, Pakistan from 2018- 2019. Of the 400 children studied in which the overall prevalence rate for intestinal parasitic infections was found to be 71.75%. Children infected with single parasite accounted for 67.94% and 32.05% were detected with poly-parasitism. Shistosoma japonicum (0.69%), Taxocara spp (0.69%) and cryptosporidium (0.69%), were identified in children living in studied areas. We conclude that there is a need for mass scale campaigns to create awareness regarding health and hygiene in children and the need for development of effective poverty control programmes. Resumo As infecções parasitárias intestinais (IPIs) são uma das principais causas de morbidade em todo o mundo e têm sido descritas como importante problema de saúde pública. O presente estudo teve como objetivo determinar a infecção parasitária incomum e a identificação de fatores de risco em crianças de 4 a 12 anos em idade escolar residentes no distrito de Lower Dir, Paquistão entre 2018-2019. Das 400 crianças estudadas em que a taxa de prevalência geral de parasitas intestinais infecções foi de 71,75%, as crianças infectadas com parasita único representaram 67,94%, e 32,05% foram detectadas com poliparasitismo. Shistosoma japonicum (0,69%), Taxocara spp (0,69%) e Cryptosporidium (0,69%) foram identificados em crianças residentes nas áreas estudadas. Concluímos que há uma necessidade de campanhas em grande escala para criar consciência sobre saúde e higiene em crianças e de desenvolvimento de programas eficazes de controle da pobreza.

Neospora caninum, Toxoplasma gondii, Cryptosporidium and Eimeria cause severe impacts on the productivity of goat herds. The objectives of the present study were to establish the prevalence of these apicomplexans in goat farms from Ecuador; to evaluate a rapid test for Cryptosporidium diagnosis and to identify the risk factors associated with the infections. A questionnaire was designed to obtain information from 24 goat farms from Zapotillo, Garza Real, Cazaderos, Limones and Paletillas parishes in Ecuador. Blood (n = 388) and feces (n = 391) samples were collected. Indirect ELISA and standard parasitological assays were carried out to evaluate the seroprevalence of N. caninum and T. gondii and to detect oocysts of Cryptosporidium and Eimeria. The overall prevalence values of N. caninum and T. gondii were 12.11% and 18.20%, Cryptosporidium spp. and Eimeria spp. oocysts were detected in 10.49% and 89.51% of the total samples. A low correlation value was found between the results obtained by Ziehl-Nielsen and the rapid test. The multinomial logistic regression analysis revealed that vitamin supplementation, age of diarrhea, frequency of deworming, pasture area, presence of artiodactyls, domestic fowl, administration of sulfas, age group, body condition, abortions, type of pastures and the presence of cattle were risk factors according to the parasite species.

The monitoring of the microbial quality of fresh products in the industrial environment has mainly focused on bacterial indicators. Protozoa, such as Giardia duodenalis, Cryptosporidium spp., Toxoplasma gondii, and Cyclospora cayetanensis, are routinely excluded from detection and surveillance systems, despite guidelines and regulations that support the need for tracking and monitoring these pathogens in fresh food products. Previous studies performed by our laboratory, within the scope of the SafeConsume project, clearly indicated that consumption of fresh produce may be a source of T. gondii, thus posing a risk for the contraction of toxoplasmosis for susceptible consumers. Therefore, preliminary work was performed in order to assess the microbiological quality of vegetables, highlighting not only bacteria (Escherichia. coli, Listeria monocytogenes, and Salmonella spp.), but also the zoonotic protozoa G. duodenalis and Cryptosporidium spp. Although all samples were found to be acceptable based on bacteriological parameters, cysts of G. duodenalis and oocysts of Cryptosporidium spp. were observed in vegetables. Moreover, it was possible to genetically characterize G. duodenalis positive samples as assemblage A, a genotype that poses risks to human health. Although these are preliminary results, they highlight the need to include protozoa in the microbiological criteria for foodstuffs, as required by EU Law No. 1441/2007, and to improve inactivation and removal procedures of (oo)cysts in fresh produce and water.

Cryptosporidium is a worldwide enteric protozoan parasite that causes gastrointestinal infection in animals, including humans. The most notable species is Cryptosporidium parvum because of its zoonotic importance; it is also the leading cause of cryptosporidiosis in preweaned calves. A cross-sectional study was conducted to determine the prevalence of Cryptosporidium infection, investigate the potential risk factors, and use molecular diagnosis to identify the predominant Cryptosporidium spp. in preweaned calves in Kuwait. Of 175 preweaned calves, Cryptosporidium antigens were detected in 58 (33.1%) using rapid lateral immunochromatography assay (IC). Calves less than one month of age (OR = 4.32, p = 0.0001) and poor hygiene (OR = 2.85, p = 0.0075) were identified as significant risk factors associated with Cryptosporidium infection. Molecular identification revealed that C. parvum (62.8%) was the dominant species infecting preweaned calves in Kuwait. In contrast, C. bovis and C. andersoni were recorded at 5.7% and 2.9%, respectively. All C. parvum gp60 nucleotide sequences were subtype IIaA15G2R1. Calves could be a source of C. parvum infection due to the similarity of the subtypes recorded previously in Kuwaiti children and preweaned calves in this study. Therefore, more research is needed to understand the Cryptosporidium transmission cycle in Kuwait.

The aim of this study was to evaluate the frequency of gastrointestinal protozoan infection in patients with hematological malignancies (HMs) undergoing intensive hemato-oncological treatment and to determine the influence of certain biological factors on the incidence of intestinal parasite infection. Stool samples were collected from hematological malignancy patients (n = 50) hospitalized at the Department of Hematology and Transplantology of the Pomeranian Medical University in Szczecin. The control group consisted of 50 healthy participants. We used a direct smear examination and a commercial immunoenzymatic test. Intestinal protozoans were detected in 16% of patients with hematological malignancies and in 6% of individuals in the control group. In stool samples from patients with HM, cysts of Giardia intestinalis (2%), oocysts of Cryptosporidium spp. (10%), vacuolar forms of potentially pathogenic Blastocystis spp. (2%), and cysts of nonpathogenic Entamoeba coli (2%) were found. Cryptosporidium spp. and Giardia intestinalis coproantigens were detected in 5 (10%) and 1 (2%) patients with HM, respectively. In three participants from the control group, vacuolar forms of Blastocystis spp. were found. In the patients with HM, a significantly higher prevalence of intestinal parasite infection was found in individuals working in the garden without protective gloves and those in contact with animals. In patients with hematological malignancies, intestinal parasites should be excluded, even during intensive chemotherapy treatment.

Cryptosporidium spp [...]

The aim of this study was to determine the effect of host body temperature and en-vironmental pH on the excystation and preservation of the ability to infection of rodent gastric cryptosporidia oocysts. The infectivity of unexcysted oocysts was further examined. Immunodeficiency SCID mice (Mus musculus) were infected with C. proliferans oocysts, then their faeces were collected and individual experi-ments were performed. The effect of temperature on excystation, when oocysts were placed in water baths at the appropriate temperature (32-44 °C) and the effect of pH, when oocysts were exposed to solutions of different pH (2-7), was investi-gated. Cell separation was then performed using a flow cytometer and the values obtained were recorded in the tables. The most oocysts excysted at 40 °C and pH 7. An autopsy of infected mice was also performed to determine the infectivity of oo-cysts from various parts of the digestive system. All taken oocyst samples were infectious for the subsequent host. Infection experiments, which were further car-ried out revealed, that unexcysted oocysts exposed to hypochlorite and laboratory temperatures retain their ability to infect. In contrast, the oocyst sporozoites that excysted were susceptible to both hypochlorite and room temperature, thus losing the ability infect the subsequent host.

Gastrointestinal strongylosis causes important economic loss in sheep production and its control by anthelmintic treatments is increasingly complicated. The first objective of this thesis was to evaluate the efficiency of some antiparasitic molecules in sheep farms. A species of gastrointestinal nematode, Haemonchus contortus, is now resistant to eprinomectin in the Ossau-Iraty dairy sheep aera. In addition, the first losses of efficacy of diclazuril on Eimeria crandallis have been characterized in meat sheep farms in France. Faced with the emergence of multiresistance to chemical treatments, alternative solutions must be implemented. The second objective of the thesis was to continue the genetic selection of sheep resistance to gastrointestinal strongyles. The genetic selection on phenotyping of rams in Manech Tête Rousse, Basco-Béarnaise and Rouge de l'Ouest breeds was continued. In the dairy sheep breeds (Manech Tête Rousse and Basco-Béarnaise) of the Pyrénées, the genetic correlations between resistance and production traits are most often unfavorable, more so in the Basco- Béarnaise breed than in the Manech Tête Rousse breed. However, co-selection is still possible, even if the genetic progress for milk production will be slowed down. In the Rouge de l'Ouest breed, the optimization of the phenotyping protocol has been carried out in such a way that its impact on the evaluation protocol of the meat aptitudes, carried out concomitantly, is as limited as possible. After having selected rams more resistant to these parasites, the third objective was to ensure that there was no increased sensitivity to digestive protozoa and that the effect of the selection on the sires was effectively found in their daughters in various farming systems. Manech Tête Rousse ewe lambs, from sires indexed for resistance to gastrointestinal nematodes, were followed during their first four months of life. Genetic selection for resistance to gastrointestinal nematodes did not influence natural asymptomatic Cryptosporidium spp. infections or Eimeria spp. oocyst excretion intensities. The proportions of pathogenic Eimeria species (E. ovinoidalis and E. crandallis) were also identical regardless of sire status. Ewes of the Manech Tête Rousse and Basco-Béarnaise breeds, sired by rams indexed for resistance to gastrointestinal nematodes, were studied during one and a half year on pasture. In Manech Tête Rousse, the effect of the sire's index was found in the spring when ewes from resistant sires excreted fewer gastrointestinal nematode eggs than ewes from susceptible sires. When H. contortus is present in the majority of the helminthofauna, the proportions of this species are generally lower in ewes from resistant rams. Finally, the last objective of this thesis was to evaluate the interest of an alicament based on plants rich in condensed tannin (sainfoin and québracho) in breeding following the manufacturer's recommendations. The alicament, although practical in its use, did not lead to a decrease in the intensity of excretion of gastrointestinal nematode eggs compared to a control group. Moreover, the cost of this drug is currently at least double that of an anthelmintic treatment. This thesis work has allowed the continuation of work on alternatives for the control of gastrointestinal strongylosis in sheep. It has also served as a basis for other research projects and technology transfer to professionals from the sheep industry in the New Aquitaine region (France)., Les strongyloses gastro-intestinales provoquent des pertes économiques importantes en élevage ovin et leur maîtrise par des traitements anthelminthiques est de plus en plus compliquée. Le premier objectif de ces travaux de thèse était d'évaluer l'efficacité de certains antiparasitaires en élevage. Une espèce de strongle gastro-intestinal, Haemonchus contortus, est maintenant résistante à l'éprinomectine dans le bassin ovin laitier Ossau-Iraty. De plus, les premiers défauts d'efficacité du diclazuril sur Eimeria crandallis ont été caractérisés en ovin allaitant en France. Face à l'émergence de multirésistance aux traitements chimiques, des solutions alternatives doivent être mises en place. Le second objectif de thèse était de poursuivre les travaux de sélection génétique de la résistance des ovins aux strongles gastro-intestinaux. La sélection génétique sur phénotypage de béliers en race Manech Tête Rousse, Basco- Béarnaise et Rouge de l'Ouest a été poursuivie. Dans les races ovines laitières (Manech Tête Rousse et Basco- Béarnaise) des Pyrénées, les corrélations génétiques entre caractère de résistance et caractère de production sont le plus souvent défavorables, de manière plus accentuée en race Basco-Béarnaise qu'en race Manech Tête Rousse. Toutefois la co-sélection reste possible, même si le progrès génétique laitier sera ralenti. En race Rouge de l'Ouest, l'optimisation du protocole de phénotypage a été réalisée de façon à ce que son impact sur le protocole d'évaluation des aptitudes bouchères, réalisé de manière concomitante, soit le plus limité possible. Après avoir sélectionné des béliers plus résistants à ces parasites, le troisième objectif était de s'assurer qu'il n'y avait pas de sensibilité accrue à des protozoaires digestifs et que l'effet de la sélection sur les pères était bien retrouvé chez leurs filles en élevage et ce, dans des systèmes d'élevages variés. Des agnelles Manech Tête Rousse, issues de pères indexés sur le caractère de résistance aux strongles gastro-intestinaux, ont été suivies pendant leurs quatre premiers mois de vie. La sélection génétique de la résistance aux strongles gastro-intestinaux n'influence pas les infections asymptomatiques naturelles à Cryptosporidium spp. ni les intensités d'excrétions d'oocystes d'Eimeria spp. Les proportions des espèces d'Eimeria pathogènes (E. ovinoidalis et E. crandallis) sont également identiques quel que soit le statut du père. Des brebis de race Manech Tête Rousse et Basco-Béarnaise, issues de béliers indexés sur le caractère de résistance aux strongles gastro-intestinaux, ont été suivies sur un an et demi au pâturage. En Manech Tête Rousse, l'effet de l'index du père a été retrouvé au printemps où les brebis issues de pères résistants excrétaient moins d'œufs de strongles gastro-intestinaux que les brebis issues de pères sensibles. Lorsque H. contortus est présent en majorité dans l'helminthofaune, les proportions de cette espèce sont généralement plus faibles chez les brebis issues de béliers résistants. Enfin, le dernier objectif de cette thèse était d'évaluer l'intérêt d'un alicament à base de plantes riches en tanin condensé (sainfoin et québracho) en élevage en suivant les recommandations du fabricant. L'alicament, bien que pratique dans son utilisation, n'a pas entrainé de diminution de l'intensité d'excrétion d'œufs de strongles gastro- intestinaux en comparaison d'un lot témoin. De plus, le coût de cet alicament est actuellement au moins le double d'un traitement anthelminthique. Ces travaux de thèse ont permis la poursuite de travaux sur les alternatives de lutte aux strongyloses gastro- intestinales chez les ovins. Ils ont également servi de base à d'autres projets de recherches et à du transfert technologique aux professionnels de la filière ovine en région Nouvelle Aquitaine.

Final Thesis Curriculum in Veterinary Medicine Cryptosporidium spp. infection is highly prevalent in Estonian and worldwide on herd level. Most infected group is young neonatal calves who also shed oocysts from early age. Cryptosporidium spp. can cause severe enteritis, diarrhea, and increased mortality along with economical losses. This thesis focuses on the dynamics of Cryptosporidium spp. infection on one Estonian dairy farm, the inflammatory response of the neonatal calf, and if and how the acute phase proteins (APP) associate with Cryptosporidium spp. infection. During infection, the innate immune system acute-phase response (APR) is activated and as a result APPs are produced. The inflammatory response in calves was assessed by measuring the major cattle APP of cattle, serum amyloid A (SAA) and haptoglobin (Hp). From the study group of calves (n=55), serum (n=264) and fecal (n=220) samples were taken from one Estonian dairy farm at 7, 10, 14 and 21- days of age. Oocyst groups were formed retrospectively, where G0 group had no oocysts, G1 1-10.000 oocysts and G2 over 10.000 oocysts. Majority of calves at 14- day of age belonged to the group G2. Mean SAA concentration peaked at the 7-day old calves, from where it steadily declined. Mean Hp concentration peaked at day ten and during that time majority of the calves (70.9%) belonged to the G2 group. The result could indicate that high numbers of Cryptosporidium spp. oocysts could influence the calves’ immune system and promote APR that is more pronounced in Hp than in SAA. Algloom krüptosporiidi nakkus on Eestis ja kogu maailmas karja tasandil väga levinud. Enamasti on nakatunud noored vasikad, kes eritavad ootsüste juba varases eas. Cryptosporidium liigid võivad põhjustada ägedat enteriiti, kõhulahtisust ja suurenenud suremust koos majandusliku kahjuga. See lõputöö keskendub krüptosporiidi liikide infektsioonidünaamikale ühes Eesti piimafarmis, vastsündinud vasika põletikuvastusele ning kas ja kuidas seostuvad akuutse faasi valgud krüptosporiidi liikide infektsiooniga. Nakatumise ajal aktiveeritakse kaasasündinud immuunsüsteemi akuutse faasi vastus ja selle tulemusena toodetakse akuutse faasi valke. Vasikatel hinnati põletikulist vastust veiste peamiste akuutse faasi valkude, seerumi amüloid A (SAA) ja haptoglobiini (Hp) mõõtmisega. Ühes Eesti piimafarmis koguti seerumi- (n=264) ja roojaproove (n=220) vasikatelt (n=55) vanuses 7, 10, 14 ja 21 päeva. Ootsüstide rühmad moodustati retrospektiivselt, kus G0 rühmas ootsüste ei leitud, G1 leiti 1–10 000 ootsüsti ja G2 üle 10 000 ootsüsti. Enamus 14-päevastest vasikatest kuulus rühma G2. Keskmine SAA kontsentratsioon saavutas haripunkti 7-päeva juures, seejärel langes pidevalt. Keskmine Hp kontsentratsioon saavutas haripunkti kümnendal päeval ja sel ajal kuulus suurem osa vasikatest G2 rühma. Tulemus võib viidata sellele, et krütosporiidi liikide ootsüstid võivad mõjutada vasikate immuunsüsteemi ja soodustada akuutse faasi vastust, mis on rohkem väljendunud Hp-s kui SAA-s.

Cryptosporidium is an apicomplexan protozoan parasite that primarily infects the gastrointestinal epithelium in humans and domestic and wild animals. The majority of studies have been focused on human, livestock, and pet infections. Hence, Cryptosporidium spp. in wildlife, including wild carnivores, remained neglected. There are several studies reporting the occurrence of Cryptosporidium spp. in wild foxes, but these are only a few molecular surveys; no data is available concerning the occurrence of this parasite in raccoon dogs and martens in Europe, and to the best of our knowledge to date, only one study has reported Cryptosporidium from badgers in Spain. Therefore, we used molecular analyses to identify and genotype Cryptosporidium spp. in wild-living mesocarnivores in Poland. A total of 322 individual fecal samples from six carnivore species, i.e., raccoon, raccoon dog, red fox, European badger, pine, and beech martens were collected and then analyzed for the presence of Cryptosporidium spp. using the nested PCR method. The appearance of PCR products in the reaction with Cryptosporidium-specific primers against the 18S rRNA and actin genes demonstrated that Cryptosporidium spp. occurred in 23.0% of all examined species of animals. Performed sequence analyses showed the presence of the Cryptosporidium skunk genotype, Cryptosporidium vole genotype II, Cryptosporidium canis dog and fox genotypes, as well as Cryptosporidium erinacei, Cryptosporidium ditrichi, Cryptosporidium suis, and Cryptosporidium alticolis, in these hosts. Molecular data presented here indicate that examined mesocarnivores may be a significant reservoir of specific and non-specific Cryptosporidium species, including those with zoonotic potential. Most studies of carnivores have described the presence of non-specific Cryptosporidium spp. in carnivore hosts, and this is probably the result of the transfer of these parasites from prey species through the digestive tract or the transfer of the parasite from a contaminated environment.

Cryptosporidium spp. are important foodborne and waterborne pathogens in humans and animals, causing diarrheal diseases. Cattle are one of the reservoirs of Cryptosporidium infection in humans. However, data on the occurrence of Cryptosporidium spp. in cattle in Yunnan Province remains limited. A total of 700 fecal samples were collected from Holstein cows (n = 442) and dairy buffaloes (n = 258) in six counties of Yunnan Province. The occurrence and genotypes of Cryptosporidium spp. were analyzed using nested PCR and DNA sequencing. Furthermore, the C. andersoni isolates were further analyzed using multilocus sequence typing (MLST) at four gene loci (MS1, MS2, MS3, and MS16), and the C. parvum isolate was subtyped by 60-kDa glycoprotein (gp60) loci. The occurrence of Cryptosporidium spp. in Holstein cows and dairy buffaloes was 14.7% (65/442) and 1.1% (3/258), respectively. Of these positive samples, 56 Holstein cow samples represented C. andersoni, four Holstein cow samples represented C. bovis, three Holstein cow samples represented C. ryanae, and one represented C. parvum. Meanwhile, only three dairy buffalo samples represented C. ryanae. MLST analysis of subtypes of C. andersoni detected four subtypes, including A5A4A2A1 (n = 7), A4A4A4A1 (n = 7), A1A4A4A1 (n = 2), and A4A4A2A1 (n = 1). One C. parvum isolate was identified as the IIdA18G1 subtype. These results revealed the high occurrence and high genetic diversity of Cryptosporidium spp. in Holstein cows in Yunnan Province, enriching the knowledge of the population genetic structure of Cryptosporidium spp. in Yunnan Province.