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Diagnostika parazitárních onemocnění a úspěšnost vybraných terapeutických postupů u lichokopytníků a sudokopytníků
HAVRDOVÁ, Nikola
This dissertation dealt with the diagnosis and therapeutic procedures for the treatment of parasitic diseases in odd-toed and even-toed ungulates with selected anthelmintics. Between 2020 - 2023, 5.359 artiodactyls and 819 solipeds, namely cattle, sheep, goats, aurochs, mouflon, deer, bison, bison bonasus, horses, donkeys and ponies, were microscopically examined for the presence of nematodes, trematodes or cestodes in faecal samples in the Czech Republic. Molecularly, 76 cattle samples, 26 bison bonasus samples and 52 bison samples were examined for the presence of trematodes and C. daubneyi was detected. Parasitic infections were monitored in naturally infected individuals, and during the study no clinical signs suggestive of parasitemia were observed in any of the monitored individuals. The most parasitic infections were evaluated for H. contortus, O. ostertagi, M. benedeni, C. daubneyi and A. perfoliata. As part of the dissertation, a total of ten anthelmintics available in the Czech Republic were chosen, focusing on individual categories of parasitic infections in various animal species. Based on laboratory analyzes of LDA tests, the species of nematode was determined according to the developmental stage of the larvae, which helped to choose the appropriate anthelmintic during treatment. In conclusion, it can be stated that almost all anthelmintics have been shown to be effective in therapeutically treated farm animals.
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Laparotomické infekce hostitelů střevními a žaludečními kryptosporidiemi
HAVRDOVÁ, Nikola
Cryptosporidium are protozoan parasites that infect the gastrointestinal epithelium of various vertebrate hosts. The genus has two major phylogenetic groups: a gastric group that infect the epithelium of the stomach and an intestinal group that infect the epithelium of the small and large intestine. Cryptosporidium are transmitted by the faecal-oral route and infect epithelial cells following excystation of the environmental oocyst stage. It has been proposed that excystation of intestinal species is triggered by exposure to the acidic stomach contents, although this has not been verified experimentally. This study aimed to determine whether exposure to stomach contents is necessary for in vivo infection by the intestinal species C. parvum and whether passage through the intestine is necessary for the gastric species C. proliferans to cause infection. It was shown that purified and non-purified oocysts of C. parvum were infectious for SCID mice following surgical inoculation directly into different parts of the small intestine, demonstrating that passage through the stomach is not necessary for infection by this intestinal species. Inoculation of the jejunum resulted in a course of infection similar to oral inoculation. Cryptosporidium proliferans was infectious for na?ve SCID mice following surgical extraction from the stomach of infected SCID mice, demonstrating that passage through the small intestine is not necessary for infection by this gastric species. However, surgical inoculation of C. proliferans oocysts directly into the intestinum tenue did not cause infection.
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Diversity, phylogeny and biology of various strains of Cryptosporidium muris
HAVRDOVÁ, Nikola
The morphological, biological, and molecular characteristics of various isolates of Cryptosporidium muris, namely HZ206 and TS03 were described. Oocysts of C. muris TS03 measuring 7.77 ? 0.23 × 5.20 ? 0.08 ?m with a length to width ratio of 1.48 ? 0.02 (n = 100) were morphometrically larger than C. muris HZ206 oocysts measuring 7.62 ? 0.40 × 6.63 ? 0.09 ?m; 1.32 ? 0.02 (n = 100) (p=0.034). Oocysts of both C. muris TS03 and HZ206 isolates obtained from naturally infected Tachyoryctes splendens and Mus musculus musculus, respectively, were infectious for na?ve 8-week-old Mastomys coucha. While the prepatent period of C. muris TS03 was 19-21 days post infection (DPI) and the animals did not lost infection within 120 DPI, animals infected with HZ206 start to shed oocysts 13-15 DPI with patent period 63-112 DPI. The accumulated value of infection intensity (AUC) in TS03 infected animals ranged from 250,000,000 to 800,000,000 oocysts per patent period (OPP) and HZ206 from 11,000,000 to 35,000,000 OPP. Histologically, a massive infection of cryptosporidia was detected in the glandular epithelium of stomach. Histopathological changes had a non-inflammatory character and included distinctive dilatation of infected parts of the glands with atrophy and metaplasia of the glandular epithelial cells. Infection with TS03 influenced the size of the stomach. While physiological weight of stomach of na?ve 12-week old mastomys and those infected with HZ206 were 0.61 ? 0.06 g and 0.70 ? 0.17 g,respectively, abnormal enlargement of stomach was observed in animals infected with TS03 (3.23 ? 0.51 g). There was no effect on feed intake among tested groups. Phylogenetic analyses based on small subunit rRNA, actin, MS1, MS2, MS3 and MS16 gene sequences revealed that C. muris TS03 is genetically distinct from other C. muris isolates. In conclusion, morphological, genetic, and biological data support the establishment of Cryptosporidium muris TS03 as a new species.
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