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OCCURRENCE AND GENOTYPISATION OF CRYPTOSPORIDIES IN OSTRICHES IN FARM BREED
HEJZLAROVÁ, Adéla
Avian cryptosporidiosis is a common parasitic disease caused by unicellular parasites belonging to the genus Cryptosporidium spp. These parasites have been described as a cause of various respiratory and gastrointestinal diseases of humans, farm and wild animals. Total of 204 faecal samples of common ostriches (Struthio camelus) were collected on four ostrich farms in the Czech Republic. Samples were screened for Cryptosporidium presence by microscopy and PCR/sequencing. Overall, 2.5 % (5/204) and 5.9 % (12/204) of animals were positive for Cryptosporidium by microscopy and PCR, respectively. Phylogenetic analysis of small subunit rRNA, actin and gp60 gene sequences showed the presence of Cryptosporidium avian genotype II (n=7) and C. ubiquitum IXa (n=5). Only ostriches infected with Cryptosporidium avian genotype II shed oocysts that were detectable by microscopy. Oocysts were purified from a pooled sample of four birds, characterised morphometrically and used in experimental infections to determine biological characteristics. Oocysts of Cryptosporidium avian genotype II measure 6.13 × 5.15 m, which is indistinguishable from C. baileyi and C. avium. Cryptosporidium avian genotype II was experimentally infectious for geese (Anser anser f. domestica), chickens (Gallus gallus f. domestica) and cockatiels (Nymphicus hollandicus), with a prepatent period of four, seven and eight days post infection, respectively and not infectious for mice (Mus musculus) and rats (Rattus norvegicus). The infection intensity ranged from 1,000 to 16,000 oocysts per gram. None of the naturally or experimentally infected birds developed clinical signs in the present study.
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Vnímavost vybraných hostitelů k infekci \kur{Cryptosporidium avium}
REIFOVÁ, Zuzana
Experimental infections with Cryptosporidium avium were carried in three different species of birds (chicken, duck and pheasant) divided into three age categories (1-day-old, 21-day-old and adult). The birds were infected peroraly using intragastric gavage with a dose of 380 thousand of oocysts in 1 ml. Faecal samples were collected daily for 30 days for a microscopic and molecular examination. While all age categories of pheasant (Phasianus colchicus) were not susceptible to C. avium infection, all age groups of domestic fowl (Gallus gallus f. domestica) and white ducks (Anas platyrhynchos f. domestica) were susceptible. Prepatent period in domestic fowl ranged from 9 to 11 days depending on the age category, in white ducks from 4 to 6 days. Patent period for both susceptible host species was longer than 30 days. Based on the results of experimental infections domestic fowl and white duck are proposed as a suitable model hosts for Cryptosporidium avium.
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Comparison of various ways of tick infection with the tick-borne encephalitis virus
VÝLETOVÁ, Eva
The aim of the bachelor thesis was to compare various methods of Ixodes ricinus tick infection with the tick-borne encephalitis virus. For infection by immersion method, less virulent TBE virus strain Neudoerfl was used resulting in 5 % of infected ticks. Using more virulent strain Hypr provided 60 % of infected ticks. 75 % of ticks became infected with the Neudoerfl virus by capillary feeding. Infection of ticks by feeding on viraemic mice was unsuccessful. Applicability of tested methods for infection of tick life stages is discussed.
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Susceptibility of pigs to various Cryptosporidium species and genotypes
KESTŘÁNOVÁ, Michaela
Three-four and 8 week old pigs (three animals per isolate) were inoculated with Cryptosporidium muris C. tyzerri, C. suis and Cryptosporidium pig genotype II at a dose of 1 × 107 oocysts per animal. Pigs inoculated with C. muris or C. tyzerri showed no detectable infection and no clinical symptoms of cryptosporidiosis during 30 days post infection (DPI), and no macroscopic changes were detected in the digestive tract after necropsy. Any developmental stages were detected in gastrointestinal tract tissue neither by histology nor PCR throughout the duration of the experiment. The infectivity of these isolates was verified on SCID mice, in which oocysts shedding started from 4 to 8 DPI. Experimental infection revealed susceptibility of both 4 and 8 week old pigs to C. suis. While parasitological, molecular and histology examination confirmed susceptibility of 8 week old pigs to Cryptosporidium pig genotype II, 4 week old pigs were not being infected with this genotype. Both C. suis and Cryptosporidium pig genotype II were detected in small and large intestine. Based on our findings, it can be concluded that pigs are not susceptible to C. muris or C. tyzzeri infection, C. suis does not have age specificity and Cryptosporidium pig genotype II is not infectious for pre-weaned pigs
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