National Repository of Grey Literature 57 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Comparative study of Trichomonas vaginalis strains with various level of metronidazole resistance
Havelka, Michal ; Tachezy, Jan (advisor) ; Kopáček, Petr (referee)
Trichomonas vaginalis is an anaerobic protozoan that causes the human disease trichomoniasis. The most commonly used drug against trichomoniasis is metronidazole. Metronidazole is highly effective, yet in some cases T. vaginalis is resistant to this drug. In T. vaginalis, we distinguish resistance to metronidazole into two types based on the conditions in which it occurs, aerobic and anaerobic resistance. Both types of resistance are associated with changes in the physiology of the parasite. The aim of this study was to characterize the changes in hydrogenosome and cytosol associated with metronidazole resistance at the proteome level in aerobically resistant clinical isolates, the aerobically resistant line MR3 and the anaerobically resistant line MR100. A further aim of this work was to characterize the function of hybrid- cluster protein and to clarify its role in resistance to metronidazole since its production is more abundant in both aerobically and anaerobically resistant T. vaginalis. This work contributed to identification of several potential proteins that could play a role in the development of metronidazole resistance and established a foothold for further metabolomic and biochemical studies of metronidazole resistant T.vaginalis.
Biogenesis and function of peroxisomes in parasitic protists
Nguyen, Thu Duong ; Tachezy, Jan (advisor) ; Verner, Zdeněk (referee)
Peroxisomes are found in majority of eukaryotes and possibly originate from the last eukaryotic common ancestor, as the proteins involved in their biogenesis are highly conserved. Enzymatic content of peroxisomes is highly diverse and their metabolic activity may vary depending on the cell type. Metabolically, peroxisomes interact with mitochondria and these organelles are functionally linked. Peroxisomes in unicellular eukaryotes are very diverse. The peroxisomes in kinetoplastids are named glycosomes because they contain several glycolic enzymes. The loss of peroxisomes occurs in certain representatives of Alveolata, and peroxisomes are entirely absent in Metamonada group. Anaerobic peroxisomes were found in Archamoebidae. They are metabolically quite distinct from their aerobic counterparts. The properties of these peroxisomes are related to the lifestyle of these protists. This work briefly summarizes information regarding the biogenesis of peroxisomes and their functions, their functional connection with mitochondria and then provide characteristics of peroxisomes in selected protists.
Effect of pathogens on the vaginal microbiome
Procházková, Jana ; Tachezy, Jan (advisor) ; Smutná, Tamara (referee)
The human body is heavily populated with a wide variety of microorganisms. These microorganisms form coherent communities, which in contact with specific human organs form microbiomes. Each microbiome is unique in its composition. The study of microbiomes enables us to describe their composition and to understand the complex interactions that occur between microorganisms and humans. Methods of microbiome analysis are constantly evolving. For example, next-generation sequencing is currently the most widely used method for the characterization of microbiomes. Bacteria of the genus Lactobacillus are the major component of a healthy vaginal microbiome in most women. A healthy vaginal microbiome is essential for maintaining the natural homeostasis and to assure a proper functioning of the female urogenital tract. Lactobacillus is also important for the protection of the vagina from pathogenic agents such as viruses, bacteria, archaea and eukaryotes. In this bachelor's thesis the major pathogens of the Bacteria and the Eukaryota domain are described. Hereby a particular focus is on Trichomonas vaginalis, which is the most prevalent pathogenic agent of the female urogenital tract worldwide. Studying the immunity of the vaginal microbiome to this parasite is therefore essential. Furthermore, the mechanisms of...
Anaerobic fungi and herbivores
Pristašová, Paulína ; Tachezy, Jan (advisor) ; Hrdý, Ivan (referee)
Anaerobic fungi Neocallimastigomycotina participate in rumen symbiotic microbiome. This highly specific group of fungi are a part of the basal lineages of the Fungi kingdom, differing from their aerobic counterparts in many aspects, including the possession of hydrogenosomes and the production of cellulosomes. Their entire life cycle occurs in the rumen, comprising of motile zoospores, which after colonizing plant biomass, germinate into vegetative thallus, forming a sporangium. In the rumen ecosystem, anaerobic fungi are primary colonizers of ingested plant biomass, where with the help of extracelullar multienzyme complexes- cellulosomes- degrade recalcitrant plant cell wall. The ability to form cellulosomes, until now observed in prokaryots only, was acquired by horizontal gene transfer from rumen symbiotic bacteria. Their long coevolution also led to many syntrophic interactions with methanogens, which utilise H2 produced by fungal hydrogenosomes. Their potential use in biotechnology includes biogas production and increased digestibility of agricultural feed. Key words: anaerobic fungi, rumen, hydrogenosome, cellulosome
Effect of endosymbionts on composition and properties of Trichomonas vaginalis exosomes
Zdrha, Alois ; Tachezy, Jan (advisor) ; Černý, Jan (referee)
Trichomonas vaginalis is a parasite of the human reproductive tract and the causative agent of trichomoniasis, the most spread non-viral sexually transmitted disease. Although trichomoniasis usually has mild symptoms, it can lead to serious adverse effects. The course of the disease is influenced by the host immune system, microbiome and virulence of the parasite. Importantly, the virulence of T. vaginalis is extremely variable, and it depends on secreted and surface molecules. Among these are proteases and adhesins, which can be secreted as part of the secretome or through extracellular vesicles (EVs). Further potential virulence factors are the endosymbionts of T. vaginalis: Trichomonas vaginalis virus (TVV) and Mycoplasma hominis. Although extensively studied, no consensus on whether TVV exacerbates trichomoniasis has been reached. The aim of this thesis is to analyse the effect of TVV on the protein and RNA exosomal cargo and to assess the cytokines induced by exosomes of TVV-positive T. vaginalis. Key words endosymbionts, dsRNA virus, TVV, exosome, parasite, Trichomonas vaginalis, bioinfor- matics
Protists in oral cavity of humans and animals.
Brixí, Kateřina ; Tachezy, Jan (advisor) ; Rada, Petr (referee)
Trichomonas tenax, Trichomonas gallinae, Trichomonas gypaetinii, Trichomonas stableri, Trichomonas equibuccalis, Trichomonas brixi, Tetratrichomonas canistomae, Tetratrichomonas felistomae and Tetratrichomonas empyemagena are unicellular eukaryotes (protists) that may occur in oral cavity of humans and domestic animals. These protozoans are mostly referred as commensals and relatively low attention is paid to them, since they usually are not primary cause of serious health problems. However, based on current knowledge, it can be concluded that more appropriate term for Entamoeba gingivalis and Trichomonas tenax would be an opportunistic pathogen, while Trichomonas gallinae is a primary pathogen. There are very little studies and findings about the rest of oral protozoans and their pathogenicity, therefore it is not possible to assess their significance for a host. Nevertheless, the oral protozoans should not be neglected, as in some cases they can cause serious health complications in their host.
Honeybee parasites and their influence on the gut microbiome.
Řezníková, Johanka ; Tachezy, Jan (advisor) ; Votýpka, Jan (referee)
Given the great ecological and economic importance of the honeybee, the health of honeybee colonies is under intense research. The scientific community is desperately trying to understand the heavy losses in the honeybee population, which we are currently facing. The reduction in their population could be caused by insecticides, weather, diet composition, disruption gut microbiome, some bacteria, viruses, and parasites. A lot of information is known about individual stress factors, less so about the interaction between them. This work is therefore focused on summarising information about a few chosen honeybee parasites with consideration for their effect on the microbiome of the digestive tract. There were chosen six of the most important and commonly discussed species of parasites: Nosema apis and Nosema ceranae, Crithidia mellificae and Lotmaria passim, Varroa destructor, and Acarapis woodi. The first chapter is dedicated to the honeybee, its taxonomy, anatomy, life in the colony, and defense against pathogens. The second chapter discusses more details of the intestinal microbiome of bees, its composition, function, and disturbance. The following sections focus on individual bee parasites and their effect on the host's intestinal microbiome.
Organelle proteomics of parasitic protists
Jedelský, Petr ; Tachezy, Jan (advisor) ; Kolářová, Libuše (referee) ; Půta, František (referee)
Advances in DNA sequencing led to a technological breakthrough, that allowed analyzis of complete genomes including those of parasitic protists Trichomonas vaginalis and Giardia intestinalis . These organisms are studied not only for their clinical importance, but also from the evolutionary point of view for their adaptation to anaerobic environment. Genome sequencing and annotations of predicted proteins alone did not bring detail view into functioning of their mitochondrion related organelles ­ in G. intestinalis mitosomes, not­participating in energetic metabolism, in T. vaginalis hydrogenosomes, producing molecular hydrogen and ATP by means of substrate phosphorylation. Traditional methods based on a fractionation by ultracentrifuging in density gradient and subsequent biochemical and enzymological analyzes were extended by one­ and two­dimensional electrophoresis with subsequent identification of proteins by mass spectrometry. Methods of multidimensional separation of peptides produced by specific proteolysis of a complex mixture...
Evolution of eukaryotic ABC transporters
Žárský, Vojtěch ; Tachezy, Jan (advisor) ; Doležal, Pavel (referee)
In the past twenty years there has been a lot of research done on ABC transporters. This group of membrane transporters was recognized as highly important due to its ubiquity in living organisms and due to the involvement of some of the ABC transporters in multidrug resistance of cancer cells and pathogens against chemotherapeutics. This medical aspect of ABC transporters was naturally the most important one for the majority of researchers. On the other hand, the biological aspects and evolution of many ABC transporters remained untouched. In this work I give an overview of ABC transporters of parasitic protozoa and focus on the evolutionary aspect of eukaryotic transporters and on mitochondrial ABC transporters, which are the most conserved ones among eukaryotic ABC transporters.
Proteomic Analysis of Trichomonas vaginalis hydrogenosone
Campo Beltran, Neritza ; Tachezy, Jan (advisor) ; Nohýnková, Eva (referee) ; Yarlett, Nigel (referee)
Trichomonas vaginalis is a human pathogen that affects annually approximately 258 million people worldwide. This parasite possesses organelles of mitochondrial origin called hydrogenosomes, which generate ATP under anaerobic conditions. The identification of the protein content at the subcellular level may provide new targets for antiparasitic drugs developments as well as it contributes for our understanding of the organelles function and evolution. The availability of protocols for organelles purification and the complete genome sequence allow the study of the organellar proteomes using mass spectrometry and bioinformatics, providing a powerful strategy that combine cell biology and proteomics. In our research, we used several approaches to identify the protein composition in hydrogenosomes and mitosomes. We performed transcriptomic and proteomic analysis to investigate the molecular responses of Trichomonas vaginalis upon iron availability. Furthermore, the changes in the proteome during the development of metronidazole resistance were also studied. The organelles separated by differential and Optiprep-sucrose gradient centrifugation were analyzed with nano- RP-HPLC/MALDI-TOF/TOF. We also used Triton X-114 phase partitioning to separate membrane proteins and iTRAQ technique to label the peptides...

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