Fascioloides magna is a trematode originating in North America. It is a significant pathogen, especially in cervids, but it can also infect ruminants kept for agricultural purposes.Adult trematodes are found in the liver tissue of their definitive hosts, where they can survive for a long period of time and produce large quantity of eggs. Those are passed through bile ducts and intestine with feces into the external environment. This thesis is focused on the morphology of individual developmental stages of F. magna. To this date only very limited number of literary resources concerning the topic had been published. Recorded results are compared with literary resources on Fasciola hepatica, a closely related trematode. The morphological characteristics of the individual developmental stages were studied by using histological, electron-miscroscopical and other methods (fluorescent labelling). The thesis also describes pathological changes of the definitive hosts' liver tissue. By means of the stated methods, the thesis expands the existing knowledge on the morphology of F. magna especially of surface structures and the distribution of the senzoric organs, some of which have been described for the very first time. Powered by TCPDF (www.tcpdf.org)

Neospora caninum e Hammondia heydorni são coccídeos formadores de cistos proximamente relacionados com outros organismos heteroxenos pertencentes ao filo Apicomplexa, como Toxoplasma gondii e Hammondia hammondi. Para saber se o cachorro-do-mato (Cerdocyon thous), um canídeo silvestre comumente encontrado do nordeste da Argentina ao nordeste da América do Sul, pode ser hospedeiro definitivo de N. caninum, exemplares de cachorro-do-mato foram alimentados com tecidos de bovinos e bubalinos naturalmente infectados por N. caninum. As fezes dos cachorros-do-mato foram colhidas e examinadas diariamente para pesquisa de oocistos. No primeiro experimento, masseter e cérebro (peça inteira dos dois órgãos) colhidos de dois bovinos de aproximadamente dois anos de idade, foram picados, misturados e fornecidos às quatro raposas em dois dias consecutivos. Duas raposas eliminaram oocistos sub-esféricos não esporulados medindo 10-13µm no oitavo e nono dias pós-infecção, respectivamente. Uma das raposas eliminou oocistos por cinco e a outra nove dias. Amostras de DNA extraída dos de oocistos de cada dia de eliminação foram analisadas por PCR com primers grupo-específicos PCR-ITS-1 e espécie-especificos Nc5-NPCR. Todas as amostras foram positivas por PCR-HSP-70 e PCR-ITS-1, mas negativas por Nc5-NPCR. A sequência de nucleotídeos PCR-ITS-1 revelou 100% de identidade com seqüências homólogas de H. Heydorni. Concluímos que H. heydorni também utiliza o cachorro-do-mato (Cerdocyon thous) como hospedeiro definitivo. O cachorro-do-mato é usualmente reportado em contato com rebanhos em diversas regiões do Brasil. Então, é razoável inferir que estes carnívoros possam exercer um importante papel nos ciclos silvestre e doméstico da infecção por H. heydorni. Em um segundo experimento, sete exemplares de cachorro-do-mato (Cerdocyon thous) foram alimentados com tecidos de 3 búfalos (Bubalus bubalis) naturalmente infectados por N. caninum. As fezes das raposas foram analisadas 30 dias antes e trinta depois da infecção experimental e nenhuma das raposas eliminou oocistos N. caninum-like nas fezes. Estes resultados sugerem que o cachorro-do-mato (Cerdocyon thous) não é hospedeiro definitivo de N. caninum, entretanto estudos adicionais são necessários. / Neospora caninum and Hammondia heydorni are two cyst forming coccidians closely related to other apicomplexans, such as Toxoplasma gondii and Hammondia hammondi with a two host life-cycle. To clarify whether crab-eating fox (Cerdocyon thous), a wild carnivore commonly found from northern Argentina to northern South America, can be final hosts of N. caninum, foxes were fed on tissues of cows and water buffaloes naturally infected with N. caninum. Faeces were examined from 30 days before to 30 days after infection. In experiment 1, the whole masseter muscle and brain from two-year old bovines are collected, minced and pooled together for the fox infection. The bovine pooled tissues were equally administered for four fox, in two consecutive days. Two foxes shed unsporulated oocysts subspherical in shape measuring 10-13µm, after eight and nine days post-infection, respectively. One of the foxes eliminated oocysts for five days, while the other fox shed oocysts for nine days. A DNA sample of oocysts detected at each day of oocyst elimination was tested by a PCR carried out employing primers directed to the common toxoplasmatiid 18S and 5.8S coding genes (PCR-ITS-1). These samples were also submitted to a N. caninum specific gene (Nc-5nPCR). All of them were positive by PCR-ITS-1 and negative by Nc-5nPCR. The PCR-ITS-1 nucleotide sequence revealed 100% identity with homologous sequences of H. heydorni. In conclusion, it is clear that H. heydorni also uses the crab-eating fox as a definitive host. The crab-eating fox is usually reported to live in close contact with livestock in several regions of Brazil. Therefore it is reasonable to infer that such carnivores may play an important role in the sylvatic and domestic cycles of H. heydorni infection. In experiment 2, seven fox consumed tissues from three N. caninum naturally infected water buffaloes. Feaces were examined from 30 days before to 30 days after infection and none fox shed N. caninum-like oocysts. These results suggest that the crab-eating fox cannot be definitive host of N. caninum; however additional studies will be necessary.

Neospora caninum e Hammondia heydorni são coccídeos formadores de cistos proximamente relacionados com outros organismos heteroxenos pertencentes ao filo Apicomplexa, como Toxoplasma gondii e Hammondia hammondi. Para saber se o cachorro-do-mato (Cerdocyon thous), um canídeo silvestre comumente encontrado do nordeste da Argentina ao nordeste da América do Sul, pode ser hospedeiro definitivo de N. caninum, exemplares de cachorro-do-mato foram alimentados com tecidos de bovinos e bubalinos naturalmente infectados por N. caninum. As fezes dos cachorros-do-mato foram colhidas e examinadas diariamente para pesquisa de oocistos. No primeiro experimento, masseter e cérebro (peça inteira dos dois órgãos) colhidos de dois bovinos de aproximadamente dois anos de idade, foram picados, misturados e fornecidos às quatro raposas em dois dias consecutivos. Duas raposas eliminaram oocistos sub-esféricos não esporulados medindo 10-13µm no oitavo e nono dias pós-infecção, respectivamente. Uma das raposas eliminou oocistos por cinco e a outra nove dias. Amostras de DNA extraída dos de oocistos de cada dia de eliminação foram analisadas por PCR com primers grupo-específicos PCR-ITS-1 e espécie-especificos Nc5-NPCR. Todas as amostras foram positivas por PCR-HSP-70 e PCR-ITS-1, mas negativas por Nc5-NPCR. A sequência de nucleotídeos PCR-ITS-1 revelou 100% de identidade com seqüências homólogas de H. Heydorni. Concluímos que H. heydorni também utiliza o cachorro-do-mato (Cerdocyon thous) como hospedeiro definitivo. O cachorro-do-mato é usualmente reportado em contato com rebanhos em diversas regiões do Brasil. Então, é razoável inferir que estes carnívoros possam exercer um importante papel nos ciclos silvestre e doméstico da infecção por H. heydorni. Em um segundo experimento, sete exemplares de cachorro-do-mato (Cerdocyon thous) foram alimentados com tecidos de 3 búfalos (Bubalus bubalis) naturalmente infectados por N. caninum. As fezes das raposas foram analisadas 30 dias antes e trinta depois da infecção experimental e nenhuma das raposas eliminou oocistos N. caninum-like nas fezes. Estes resultados sugerem que o cachorro-do-mato (Cerdocyon thous) não é hospedeiro definitivo de N. caninum, entretanto estudos adicionais são necessários. / Neospora caninum and Hammondia heydorni are two cyst forming coccidians closely related to other apicomplexans, such as Toxoplasma gondii and Hammondia hammondi with a two host life-cycle. To clarify whether crab-eating fox (Cerdocyon thous), a wild carnivore commonly found from northern Argentina to northern South America, can be final hosts of N. caninum, foxes were fed on tissues of cows and water buffaloes naturally infected with N. caninum. Faeces were examined from 30 days before to 30 days after infection. In experiment 1, the whole masseter muscle and brain from two-year old bovines are collected, minced and pooled together for the fox infection. The bovine pooled tissues were equally administered for four fox, in two consecutive days. Two foxes shed unsporulated oocysts subspherical in shape measuring 10-13µm, after eight and nine days post-infection, respectively. One of the foxes eliminated oocysts for five days, while the other fox shed oocysts for nine days. A DNA sample of oocysts detected at each day of oocyst elimination was tested by a PCR carried out employing primers directed to the common toxoplasmatiid 18S and 5.8S coding genes (PCR-ITS-1). These samples were also submitted to a N. caninum specific gene (Nc-5nPCR). All of them were positive by PCR-ITS-1 and negative by Nc-5nPCR. The PCR-ITS-1 nucleotide sequence revealed 100% identity with homologous sequences of H. heydorni. In conclusion, it is clear that H. heydorni also uses the crab-eating fox as a definitive host. The crab-eating fox is usually reported to live in close contact with livestock in several regions of Brazil. Therefore it is reasonable to infer that such carnivores may play an important role in the sylvatic and domestic cycles of H. heydorni infection. In experiment 2, seven fox consumed tissues from three N. caninum naturally infected water buffaloes. Feaces were examined from 30 days before to 30 days after infection and none fox shed N. caninum-like oocysts. These results suggest that the crab-eating fox cannot be definitive host of N. caninum; however additional studies will be necessary.

Migration within the body of an infected host is one of the most important parts in the life cycle of flukes, including schistosomes. Migration of avian and mammalian visceral schistosomes has been a quite well studied topic (Haas a Haeberlein, 2009), which became more attractive after the discovery of T. regenti, an avian schistosome which is able to migrate through the nervous tissues of infected birds and mammals as well. Migration of T. regenti and T. szidati schistosomula within the definitive (duck) and the accidental (mouse) hosts is the main topic of the diploma thesis. This work continues with the research of K. Blažová (Faculty of Science, Charles University in Prague) who studied migration of T. regenti within the definitive hosts infected perorally with cercariae or hepatopancreases of the infected intermediate snail, Radix lagotis (unpblished). She proved that T. regenti schistosomula are able to use the central nervous system for migration to the nasal mucosa of infected birds. In our work, we focused on the early phase of migration within the perorally infected birds and mice. Invasion of esophagus by T. regenti cercariae in vitro is not conditioned by secretion of glandular products, including cathepsin B2 of T. regenti (TrCB2). Activity of TrCB2 against mucins, the main components...

Trichobilharzia regenti is a nasal avian schistosome which has during the initial phase of infection an affinity to the nervous system. Larvae migrate through the central nervous system to the nasal mucosa of waterfowl, where they mature and reproduce. Until now this infection phase has been described only marginally. Adults are located in the nasal mucosa approximately from 13th to 24th day post infection. During this life phase, they migrate through the vascularized connective tissue and lay eggs, the presence of which has been detected in the tissue only. Maturation and hatching of miracidia occur in the tissue (unlike human schistosomes). The parasite causes inflammation, and the tissue is infiltrated with immune cells. Lymphocytes, granulocytes, macrophages, plasma cells and giant multi-nuclear cells were described by histological methods. The thesis is focused on a more detailed description of cellular immune response and histopathological changes of the tissue by means of histological stains, and antibody/lectin probes. The flukes were observed more frequently in the blood vessel lumen, together with a higher number of immune cells compared to the healthy duck. Infiltration by a high number of lymphocytes occurred in the tissue, the macrophages were frequently observed in clusters around the...