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Cathepsins B of the bird schistosome, Trichobilharzia regenti
Dolečková, Kateřina ; Horák, Petr (advisor) ; Grevelding, Christoph (referee) ; Horn, Martin (referee)
1. Overview Schistosomes have achieved first position among parasitic helminths, because some of them are the etiological agents of a serious human parasitic disease, schistosomiasis, which affects over 200 million people in tropical and subtropical countries (WHO, 2001). Other schistosomatids, such as the bird flukes of the genus Trichobilharzia, have also implications for human health. Although they can mature only in specific hosts (birds), their invasive larvae - cercariae - are able to penetrate also human skin due to chemical signals similar to those present on bird skin (Haas and van de Roemer 1998). Repeated infections result in an inflammatory reaction of the skin called cercarial dermatitis. Due to the increasing number of outbreaks all around the world, cercarial dermatitis is cons disease (Kolářová 2007idered as re-emerging ; Larsen et al. 2004). Among schistosomes, Trichobilharzia regenti is the only species described so far having a unique migration route within vertebrate hosts: after penetration of the skin, the invasive larvae enter peripheral nerves and continue via the spinal cord and central nervous system to the nasal cavity of birds, causing neuromotor disorders or paralyses of birds and even experimental mammals (Hrádková...
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Parasites And Their Preparation For School Utilization
Chlumová, Kateřina ; Říhová, Dagmar (advisor) ; Hanel, Lubomír (referee)
This diploma thesis deals with common parasites of game animals, animals and human occurring in the territory of the Czech Republic. It focuses on their fixation and general preparation of such specimens for usage in teaching of Science. The first part is devoted to the phenomenon of parasitism, and the history and definition of this concept. Systematic hierarchy of various unrelated parasitic groups is clarified. The second part provides the list of parasites, from the evolutionary original to the highly derived groups. We give an overview of their morphology and anatomy with the emphasis on their life cycle. The detailed knowledge of life cycle is essential for obtaining specimens. In each group, we indicate methods of collection and fixation in detail. The co called smartmicroscope represent the main point of the third part of proposed diploma thesis. Text of the thesis is supplemented with pictures taken by smart microscope, as well as by common microscope. KEY WORDS parasite, parasitism, mikropredatore, vector, fixation, preparation, smart mikroscope
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Naegleria: from free-living protist to brain eating deadly pathogen
Matějková, Magdalena ; Mach, Jan (advisor) ; Marková, Lenka (referee)
N. fowleri is mostly a free-living amoeboflagellate which, in favorable conditions, can occasionally adopt a parasitic lifestyle. In such cases, the amoeba becomes causative agent of primary amoebic meningoencephalitis, a severe and largely fatal disease occurring in several mammals including humans. The treatment of this disease is complicated by many unwanted side-effects of available drugs and a lack of prompt diagnostic methods. Within the Naegleria genus, N. fowleri is the only human pathogen. According to up-to-date knowledge, the pathogenicity of this species is due to its metabolic properties as well as to a particular set of proteins expressed by this protist. Besides a wide scale of enzymes, some of these proteins participate in the formation of cellular structures which are crucial for the pathogenesis. All these particularities should be targeted in a search for a better treatment. The thesis is focusing on a comparison of N. fowleri with related species N. gruberi and N. lovaniensis, stressing out the differences of N. fowleri from these non-pathogenic species. Key words: Naegleria fowleri, primary amoebic meningoencephalitis, immune response, pathogenesis, facultative parasitism
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Proteolytic enzymes of the blood fluke Schistosoma mansoni: pathobiochemistry and their use in biomedicine
Leontovyč, Adrian ; Mareš, Michael (advisor) ; Kašný, Martin (referee) ; Mikeš, Libor (referee)
Blood flukes of the genus Schistosoma are causative agents of the disease schistosomiasis, which affects more than 250 million people worldwide and together with malaria represents the most important parasitic infection. There is a high risk of resistance development against the only drug in use, therefore novel therapeutic approaches for schistosomiasis are intensively researched. Proteolytic enzymes of schistosomes are crucial for their survival in the host and thus are promising drug and vaccine targets. This thesis is focused on two proteases of the human blood fluke Schistosoma mansoni, which were produced as recombinant proteins and functionally characterized. The first one is serine protease SmSP2, which is localized at the surface of the adult worms and secreted into the blood of the host. It was identified as a vasodilatory and fibrinolytic agent, and its modulatory role in host-parasite interactions was proposed. The second one is cysteine cathepsin SmCL3, which is involved in the digestion of host blood proteins serving schistosomes as nutrients. Potent peptidomimetic inhibitors of SmCL3 were identified, and their antischistosomal activity was demonstrated in an assay with live parasites. The thesis provides new important information about S. mansoni proteases, their pathobiochemistry...
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Biologically active compounds of selected model trematodes
Kurečka, Martin ; Kameník, Zdeněk (advisor) ; Mikeš, Libor (referee)
Trematoda are parasites known for their ability to manipulate their host for survival and reproduction. They have complex life cycles with the intermediate host represented by mollusks and the definitive host, represented by vertebrates. This work focuses on three medically important genera of trematodes: Schistosoma, Fasciola and Opisthorchis. The aim of this work is to summarize biologically active low molecular weight substances that parasites modulate or produce in order to manipulate their host. The result of the work is a literature research of a comparative change in the concentration of metabolites of infected and uninfected trematode hosts with a focus on the analytical method used. Metabolomics deals with a comprehensive analysis of the metabolism of biological samples. It uses spectrometric analytical methods such as nuclear magnetic resonance and mass spectrometry combined with gas or liquid chromatography. Part of the work is also a summary of the importance, development and perspectives of metabolic profiling in parasitology. Current research in this area focuses mainly on vertebrate hosts. In addition, for vertebrate hosts, the sum of studied substances is still much broader than that in intermediate hosts. In intermediate host studies also focus on different types of substances,...
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The role of biting midges in avian blood parasites transmission
Chobotová, Kristýna ; Brzoňová, Jana (advisor) ; Kočišová, Alica (referee)
Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are hematophagous in- sects mainly important as vectors of viral diseases of farm animals. They have shifted to the forefront of scientific interest in the Czech Republic primarily in relation to the Bluetongue Virus spread since 2007. However, they have been often ignored as vectors of parasitic infec- tions, especially if these are not pathogens of economic importance. In birds, which are the focus of this bachelor's thesis, biting midges are the most significant vector mainly for the genus Haemoproteus, they transmit at least 24 species of these protozoa. On the other hand, they are proven vectors for only one species of the genus Leucocytozoon - L. caulleryi. Trans- mission has been proven for three species of the genus Trypanosoma - T. avium, T. bennetti and T. everetti. Biting midges also transmit helminths of the family Onchocercidae, they play a role as vectors for the genera Eufilaria, Chandlerella and Splendidofilaria. The goal of this bachelor's thesis is to gather information about biting midges as vectors of avian blood parasites - protozoa of the genera Haemoproteus, Leucocytozoon and Trypanosoma and helminths of the family Onchocercidae. Key words: biting midges, parasite, vector, host, bird, Haemoproteus,...
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Invasion of the host cell by the parasitic protist Plasmodium falciparum.
Charvátová, Klára ; Doležal, Pavel (advisor) ; Tůmová, Pavla (referee)
Plasmodium falciparum is an intracellular parasite that causes tropical malaria. Although plasmodium is not a problem in the middle latitudes, in tropical and subtropical regions it poses a great health threat. This specifically concerns little children, which constitute more than a half of the victims. This thesis discusses the invasion of the red blood cell by a merozoite, which is a key step of the parasite life cycle responsible for the disease development. The main part of the thesis deals with proteins secreted by organelles of the invasive apparatus of plasmodium cell. It is preceded by a chapter introducing basic information on P. falciparum and malaria. The end of the thesis contains a chapter on the parasite exit from the red blood cell. Key words Invasion, plasmodium, parasite, merozoite, red blood cell, tight junction, gliding motility, apical complex, micronemes, rhoptries
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Influence of bird schistosome Trichobilharzia regenti on haemocyte activity of lymnaeid snails
Skála, Vladimír
Gastropod molluscs are naturally exposed to various pathogens such as bacteria, or multicellular parasites that include digenetic trematodes (digeneans) which develop in snails. To combat these pathogens gastropods have evolved a sophisticated internal defence system that is composed of humoral and cellular arms. Lectins are probably the most important humoral components, whereas haemocytes represent the main effector cells. Immunity is one of the important factors determining compatibility/non-compatibility of gastropods and pathogens (particularly snails and trematodes). The introductory part of this thesis includes a review of literature focused on the components of the gastropod immune system and their reactions against pathogens represented by bacteria and digeneans. Additionally, selected immunomodulations caused by compatible digenean species are reviewed. Experimental work (presented in publications) focused mainly on the influence of the bird schistosome Trichobilharzia regenti on haemocyte activities of two lymnaeid snail species, Radix lagotis and Lymnaea stagnalis that are susceptible or refractory to the parasite, respectively. This schistosome parasite causes neuromotor disorders in specific definitive hosts (waterfowl), but it also causes cercarial dermatitis in accidental hosts...
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Role of exosomes and ectosomes in Trichomonas vaginalis virulence
Göblová, Rebeka ; Tachezy, Jan (advisor) ; Ditrich, Oleg (referee)
Trichomonas vaginalis is a causative agent of the most common non-viral sexually transmitted disease with approximately 275 mil new cases annually. Virulence of this parasitic depends on at least four factors: cell shape transformation, cytoadherence, secretion of cysteine proteases, and presence of endosymbionts. Over the past decades, extracellular vesicles appeared being another important player in the host-parasite interaction. It was discovered that T. vaginalis is one of the protists that can shed the extracellular vesicles such as exosomes and ectosomes. These vesicles are possibly involved in host-parasite communications, however limited information is available about their function. To investigate a possible role of exosomes in T. vaginalis virulence, we first selected suitable strain, which is free of endosymbionts (TV 17-2MI). Next we prepared six clones of TV 17-2MI strain to test whether the strain is homogenous concerning the virulence, or there are differences in virulence among individual cells. Mouse intraperitoneal virulence tests revealed that the clones displayed significant differences in virulence level, particularly in abscess formation and mortality of infected animals. Thus, for the first time we demonstrated heterogeneity of cells derived from a single T. vaginalis strain...
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Interaction between hydrogenosomes and endoplasmic reticulum in Trichomonas vaginalis
Kučerová, Jitka ; Tachezy, Jan (advisor) ; Černý, Jan (referee)
Endoplasmic reticulum-mitochondria encounter structure (ERMES) is a protein complex tethering ER and mitochondria. ERMES consists of four core subunits - Mmm1, Mmm2 (Mdm34), Mdm10 and Mdm12. It was first discovered in Saccharomyces cerevisiae and most functional information is based on studies of this organism. ERMES affects mitochondrial distribution and morphology, participates in lipid trafficking and is important for homeostasis of the cell. In Trichomonas vaginalis, the human urogenital parasite, three genes for putative, highly divergent components of ERMES complex were predicted. However, the cell localization of these proteins and their function is unknown. This thesis is focused on investigation of ERMES components in T. vaginalis, their cellular localization, interactions between components and identification of their possible interacting partners.
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