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Diverzita endoparazitů lišek polárních
PAVLOVIČOVÁ, Markéta
The foxes represent a reservoir of zoonotic infections therefore it is important to be familiar with an occurrence of possible diseases. Arctic fox (Vulpes lagopus) faeces were collected between 2003 and 2011 from various locations on Bylot Island, Canada. These samples were consequently treated with microscopic and molecular methods to prove the presence of microsporidia, cryptosporidia and giardia. The presence of a specific DNA of Cryptosporidium was detected in two samples and specific DNA of Microsporidia was detected in 34 samples for genus Encephalitozoon and in five samples for genus Enterocytozoon. None of the animals showed any symptoms of a diarrhoea. Subsequent analyses showed the presence of the Cryptosporidium canis fox genotype, Encephalitozoon cuniculi II and III genotypes and Encephalitozoon hellem genotype 1A. None of the examined faeces samples were positive for the presence of specific G. intestinalis DNA. Results of the thesis show that Artic foxes are mainly infected by microsporidia of the genus Encephalitozoon, while the occurrence of other observed parasites was rare.
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Čerstvé a měkké sýry jako potenciální zdroj \kur{Encephalitozoon cuniculi}
VECKOVÁ, Tereza
The aim of this work was to determine the occurrence and prevalence of Encephalitozoon cuniculi in goat's milk and faeces, and to evaluate the effect of pasteurization and curdling in goat cheese production on the infectivity of E. cuniculi spores for immunodeficient (SCID, CD4-/- and CD8-/-) and immunocompetent (BALB / ca C57BL/6) mice. Under experimental conditions, spores of E. cuniculi genotype II (557,000 spores in 1 g of cheese) remain viable in fresh cheeses treated by pasteurization at 72 ° C for 20 seconds and are able to cause infection in laboratory animals. Using nested PCR, specific DNA of E. cuniculi genotype I and genotype II was detected in eight of the nine goat cheeses purchased from various producers/breeders in the Czech Republic in the amount of 1 to 202 spores per 1 g of cheese. These cheeses were fed to immunodeficient and immunocompetent mice at a dose of 60 g/mouse within 24 days. The results of the experiment showed that spores of E. cuniculi genotype I and II remain viable in both fresh and soft cheeses and are able to cause infection in laboratory animals. Based on the results obtained, fresh and soft cheeses should be considered as a potential source of E. cuniculi infection for humans.
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Střevní paraziti ptáků na Svalbardu
ŽÁNOVÁ, Veronika
The study aimed to obtain essential knowledge about the distribution of intestinal parasites of birds occurring in Svalbard. Noninvasive coprological techniques were used to detect coccidian, cryptosporidian and microspordian parasites. The research included field collection of faecal samples and laboratory examination by microscopic and molecular methods.
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Interactions between microsporidial parasites and the host cladoceran Daphnia pulex in a simple environment of a forest pond
Krylová, Pavla ; Petrusek, Adam (advisor) ; Hyliš, Miroslav (referee)
Among the most common endoparasites who infected small crustacean Daphnia pulex include microsporidia. These intracellular parasites appear to look like a simple single- celled organisms, but their cell structure and lifecycle prove the opposite. Microsporidia are species-specific. Although they infected most organisms of the animal kingdom, they are not yet sufficiently understood. This theses is inderectly followed up to the studies of waterflea Daphnia longispina and microsporidia Berwaldia schaefernai from the dam reservoirs The aim was to analyze closer microsporidian infection on host Daphnia pulex in a forest pool with simple enviroment, which included monitoring time dynamics of Daphnia population and identification infection caused by microsporidia Berwaldia singularis and yet unknown microsporidia labor-marked "HVH". Laboratory work included determination of zooplankton and parasites, calculation of prevalence, laboratory experiments with transmission of microsporidian infection between healthy and infected flea culture or by isolated spores. Genetic analysis of aquatic invertebrates from the forest pool, especially larvae of mite and mosquitos, helped make closer microsporidian life cycle and hypothesis about secondary hosts, for the presence of pathogen DNA using specific DNA...
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Porcelain disease in crayfish: biology, impacts and distribution
Jelínková, Tereza ; Balcarová, Eva (advisor) ; Vávra, Jiří (referee)
The porcelain disease is a disease affecting crayfish caused by the microsporidium Thelohania contejeani. This intracellular parasite attacks muscle cells of the host and fills them with spores. This leads to white or opaque colouration of the abdominal muscle of crayfish, which is characteristic for this disease. The parasite gradually attacks more muscle fibers which probably leads to decrease of locomotor activity of affected crayfish and finally may result in their death. T. contejeani at low prevalences does not represent a real danger to crayfish populations and thus it is not as serious threat as crayfish plague. However, it has been associated with several cases of mass mortalities too. This thesis summarizes essential findings about infection by this parasite, analyzes its impacts to the host and factors that can influence transmission and progress of this disease. It also describes a life cycle of T. contejeani, summarizes records of the occurrence of this parasite and evaluates risks which it poses to crayfish populations. Finally, methods used to detect infection are described. Keywords: Thelohania contejeani, porcelain disease, crayfish, microsporidia, parasite, muscle
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Microparasites and fecundity of Daphnia at environmental gradients of canyon-shaped reservoirs
Hubová, Jana ; Petrusek, Adam (advisor) ; Macháček, Jiří (referee)
The original aim of my diploma thesis was examination of fixed samples of cladocerans from the Daphnia longispina species complex from reservoirs Vír and Vranov for the presence of 4 groups of microparasites: microsporidia, oomycetes, the protozoan Caullerya mesnili, and the yeast Metschnikowia bicuspidata. The next aim was to determine the effect of parasites on Daphnia fecundity, and determination of their spatial and temporal distribution within reservoirs. From the total number 4452 of examined Daphnia females, however, only 56 individuals were infected. This number was not sufficient for the planned analyses. As I recorded for all examined individuals the clutch size, I thus dealt to a large extent with an alternative issue: the temporal and spatial variation of, and the influence of environmental factors on Daphnia fecundity. Both studied reservoirs are characteristic by canyon-shaped profile that allows formation of environmental gradients on the horizontal as well as vertical axis. The results confirm that reservoir identity, season, and location within the reservoir (or gradient of food supply) have all significant effects on fecundity. During my work I have encountered difficulties associated with determining microparazites from fixed zooplankton samples. The appendix section of my thesis...
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Structure and function of the invasion apparatus of microsporidia
Dohnálek, Vít ; Doležal, Pavel (advisor) ; Vávra, Jiří (referee)
Microsporidia are obligate intracellular parasites that cause significant economic damage and can infect humans. They had evolved highly specialized invasion apparatus that is unique to them. During the invasion the sporoplasm is released from the spore wall and it is transferred to the host cytoplasm through the polar tube. Current research on the invasion apparatus has been focused mainly on the polar tube that is its most prominent structure. Polaroplast and posterior vacuole remain out of the main interest, although they are necessary for the activation and execution of the invasion. If the right combination of environmental factors occurs, the organization of the polaroplast begins to change, the posterior vacuole starts to swell and the polar tube is discharged. Sporoplasm is eventually pushed through the tube into the host cell by growing posterior vacuole. The mechanism has not been explained yet however plenty of theories are trying to explain the germination. This work summarizes current theories and knowledge of structure and function of particular parts of the invasion apparatus. Key words: Microsporidia, invasion, polar tube, intracellular parasitism, germination
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The invasion apparatus of protozoan parasites
Novotná, Veronika ; Petrů, Markéta (advisor) ; Štáfková, Jitka (referee)
Protozoa parasitism has evolved many times independently in the history of eukaryotes. Some organelles were reduced, and specific invasion apparatuses were developed by adapting to the host. These apparatuses help to penetrate host cells and escape the immune system. The thesis summarizes the findings of the invasion apparatus and invasion of four selected unicellular protozoan parasites of genus Plasmodium, Microsporidia, Ichthyobodo and Rozella. Each chapter includes general knowledge of the parasite, its structure and life cycle. Keywords: Apicomplexa, Plasmodium, Microsporidia, Ichthyobodo, Rozella, merozoite, glideosom, moving junction, polar tube, germination, cytostome, zoospore, germ tube;
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