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Can symbiotic bacteria of storage mite Acarus siro alter its response to biocides?
Navrátilová, Blanka ; Hubert, Jan (advisor) ; Mourek, Jan (referee)
Storage mite Acarus siro is one of the most distributed stored product mites in the world. It infests various products (grains, dried fruits, meat products, animal feed etc.) and causes allergic reactions in humans. For these reasons, it is important to find an effective strategy to suppress or even better to eliminate the mite from the storing facilities. Historically, there have been reported cases of the mite being resistant to several pesticides. In this thesis, four populations of Acarus siro were exposed to pesticides in different concentrations - first in the form of solutions and next as a diet additive. The populations showed divergent sensitivity to four selected pesticides (pirimiphos-methyl, chlorpyriphos-methyl, deltamethrin and deltamethrin in combination with piperonyl butoxide). The biggest differences were recorded in response to solutions of pirimiphos-methyl. This pesticide was then added to standard rearing diet in five concentrations. The mite populations were exposed to this died for 3 weeks. Control and pesticide-treated diet microbiome analyses revealed that 0.0125 µg×g-1 concentration causes hormoligosis in 6L and 6Tu strains. The same concentration was responsible for microbiome change in 6Z strain. Exposure to 1,25 µg×g-1 concentration caused microbial shifts in 6Z and...
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Bacteria associated with decomposing deadwood
Tláskal, Vojtěch ; Baldrian, Petr (advisor) ; Uhlík, Ondřej (referee) ; Bárta, Jiří (referee)
Deadwood is a hotspot of microbial diversity and its decomposition contributes to carbon and nitrogen cycling in temperate forests. The historically recognized importance of fungi in the decomposition of deadwood has recently been complemented by the description of bacterial functions thanks to the rapid progress of culture-independent methods based on the analysis of nucleic acids. To study different aspects of deadwood decomposition, a temperate mixed forest in Zofinsky prales National Nature Reserve was selected as a site with rich historical forestry data where deadwood decomposition represents an important process in wood turnover. The aim of this thesis is to describe role of bacteria in deadwood decomposition at fine scale resolution with respect to community composition, enzyme transcription, and metabolic potential of dominant species. Effects of deadwood age together with pH and water content on the bacterial community composition proved to be more important than tree species identity. Bacteria showed distinct composition between early and late community in decomposing deadwood. The bacterial community was also under a significant influence of fungal community composition. Despite being in a close contact, bacterial and fungal communities differed significantly between deadwood and the...
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The role of microorganisms and other factors in the process of autoimmune uveitis
Dušek, Otakar ; Heissigerová, Jarmila (advisor) ; Rozsíval, Pavel (referee) ; Krulová, Magdaléna (referee)
The role of microorganisms and other factors in the process of autoimmune uveitis Abstract The aim of this work was to gain new knowledge about the influence and the mechanisms of the effect of microorganisms in the process of autoimmune uveitis. A mouse model of experimental autoimmune uveitis (EAU) was used and the influence of oral broad-spectrum antibiotic, i.e. metronidazole, as well as probiotic bacteria Escherichia coli O83:K24:H31 (EcO) nad Escherichia coli Nissle 1917 (EcN) were tested in preventive and therapeutic regimens. The grade of inflammation was assessed clinically in vivo and histologically post mortem. Immunological analysis of lymph nodes and Peyer's patches were performed. Evaluation of the effect of metronidazole proved significant reduction of inflammatory activity in both regimes - intitiation 1 week or 2 weeks before the EAU induction. In case of probiotics, protective effect was proved only in case of live EcN administered 2 weeks before or from the time of EAU induction. Its protective effect was accompanied with decreased interphotoreceptor retinoid-binding protein (IRBP)-specific T-lymphocyte response in the sentinel lymph nodes of the site of immunization 7 days after the induction of EAU and cervical lymph nodes as soon as there were apparent clinical signs of intraocular...
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Metabolomics in the study of microbiome
Nazmutdinova, Anastasiia ; Kuzma, Marek (advisor) ; Cahová, Monika (referee)
Inflammatory bowel disease is a serious condition with an incomplete etiology and pathogenesis. In this thesis, a mouse model of sodium dextran sulfate-induced inflammation was used to study different changes in the metabolism of germ-free and conventionally raised mice due to the development of the inflammatory process. NMR metabolomics of fecal, urine and serum samples, combined with uni- and multivariate statistical analysis, were used to characterize the changes. It was shown that the metabolic signature differs between germ-free and conventional mice. In germ-free mice, significant amounts of carbohydrates were found in feces. Their levels decreased during inflammation as they were excreted in urine. In contrast to conventional mice, germ-free mice also excreted large amounts of amino acids in feces during the developing inflammation. Disorders of sugar and protein metabolism found in germ-free mice indicate severe malnutrition caused by inflammation. The results show that the presence of a microbiome represents a protective mechanism against significant disruption in the body. A stability study of fecal extracts of healthy conventionally colonized mice confirmed that none of the identified and quantified metabolites showed significant systemic changes in several consecutively collected...
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Human nutrition, Bacteroides fragilis and the immune system
Veigertová, Tereza ; Hrdý, Jiří (advisor) ; Podzimek, Štěpán (referee)
The presence of bacteria in the human body is a crucial factor for immune system development and its appropriate functioning. This bachelor thesis focuses on the beneficial effects of Bacteroides fragilis and explores the possibility of altering its abundance in the colon by dietary intervention. Both Czech and foreign literature was reviewed and the practical part was carried out using a questionnaire survey. The research indicates that it is possible to affect the proportional representation of Bacteroides fragilis in the colon with specific nutrients and dietary habits. Additionally, the theoretical part describes the benefits of this bacterial species on the human immune system. Bacteroides fragilis produces short-chain fatty acids, antimicrobial substances and polysaccharide A, which are the principal components that influence the host. The practical part builds upon the findings of the theoretical part. It investigates the knowledge of a random sample of Czech citizens about the effect of diet on microbiota composition. It also explores people's view on probiotics and their acquaintance with food composition. The conclusion of the thesis is a correlation between the theoretical and practical part. The intestinal microbiota is a relatively compact unit with complex interactions. Diet can not...
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RNA analysis of nasopharyngeal swab
Vítková, Magdalena ; Steiner Mrázová, Lenka (advisor) ; Hojný, Jan (referee)
The nasopharyngeal swab is a very heterogeneous easily available sample which is used to diagnose infectious diseases of the upper respiratory tract. Recently, the swab is increasingly used in biomedical research. The nasopharynx is the place of contact between the external and internal surrounding of an individual and the first immune response to the intrusion of pathogens. Mucosal damage initiates inflammatory and regenerative processes. The nasopharyngeal mucosa is permanently inhabited by a large group of microorganisms which influence the process of the disease. Therefore, the nasopharyngeal swab is a very rich source of host cells and its microbiome. The introduction of the method of massive parallel sequencing, has developed and automated methods for DNA and RNA isolation. It also led to a significant reduction in the cost of their analysis and provides an information about the host genome, the presence of microorganisms and the current level of expression of host and pathogen genes as well. Thanks to the introduction of the single cell sequencing method, it is possible to monitor the interactions of individual cell types under physiological conditions and during the immune response. The aim of this work is to provide an overview of the biological function of the nasopharynx, its cellular...
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Roles of environmental factors and microbiome in type 1 diabetes
Novotná, Kateřina ; Funda, David (advisor) ; Cahová, Monika (referee)
Type 1 diabetes mellitus (T1DM) is an insulin-dependent autoimmune disease. Its onset is characterized by an autoreactive self-destruction of β-cells within pancreatic islets. T1DM is influenced by multiple genetic predispositions, but since the incidence of the disease has increased dramatically in the past decades, especially in developed, western-type countries, the importance of the environmental factors has become obvious. There are various significant environmental influences that need to be addressed in the equation of variables. This bachelor thesis deals with the environmental variables and their mechanisms in T1DM and focuses on several areas of interest. It introduces frequently used spontaneous animal model of T1DM, pathogenetic mechanisms and T-cells in T1DM as well as regulatory immune cells and their mechanisms, in the light of hygiene and another hypothesis. Next it addresses the role of intestinal microbiota, dietary factors, mucosal immunity, their mechanisms and interactions in T1DM and extends to other, less researched, but important environmental variables such as circadian rhythm in connection with circadian gene expression depending on the rhythmicity of light/dark rotation and timing of food intake throughout the day, psychological/oxidative stress, and the effects of...
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Tool for Visualization of Microbiome Data
Mišáková, Silvia ; Martínek, Tomáš (referee) ; Smatana, Stanislav (advisor)
Táto práca sa zameriava na vytvorenie nového nástroja pre vizualizáciu mikrobiomových dát. Vytvorený nástroj používa pre redukciu dimenzií analýzu hlavných komponent (PCA) a analýzu hlavných súradníc (PCoA). V prípade výpočtu dištančnej matice sú použité metriky Bray-Curtis odlišnosť a UniFrac. Spracované dáta sú následne ofarbené na základe užívateľom zvolených metadát. Výsledky sú prezentované pomocou dvoch typov grafov. Prvý z nich je stĺpcový a zobrazuje podiel každej hlavnej zložky. Druhý, bodový graf, vizualizuje konečný výsledok požadovanej analýzy. V rámci práce bola pridaná možnosť stiahnuť si vypočítanú maticu a taktiež tabuľku prvých N hlavných zložiek vypočítaných danou analýzou.
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The Mechanism of Pathogenesis of Experimental Autoimmune Uveitis and Possilbilities of Their Regulation
Klímová, Aneta ; Heissigerová, Jarmila (advisor) ; Pitrová, Šárka (referee) ; Holáň, Vladimír (referee)
Introduction:Uveitis in an ocular inflammation affecting mostly people of working age. Uveitis is responsible for severe visual impairment despite of expanding new therapeutics. The animal models of uveitis were established, because the wide clinical variability of uveitis limits the studies in human medicine. The goal our project was to establish a reproducible model of experimental autoimmune uveitis in Czech Republic, and further on this model to observe the frequency of CD3+ and F4/80+ cells in retina, to assess the influence of microbial environment on intensity of intraocular inflammation and to test the therapeutical possibilities. Material and methods: The C57BL/6J mice were immunized by retinal antigen (IRBP 1-20, interphotoreceptor retinoid binding protein), enhanced by complete Freund's adjuvant and pertussis toxin and mild posterior autoimmune uveitis was induced. The mice were bred in conventional and germ-free (gnotobiotic) conditions. The uveitis intensity was evaluated in vivo biomicroscopically and post mortem histologically on hematoxylin eosin stained sections according to the standard protocol. The histological eye specimen were analyzed also by imunohistochemisty and by flow cytometry. Each experiment was performed for 35 days. The conventional mice with uveitis were treated...
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Biofilm formation in probiotic cultures and its application in pharmacy
Ryšávka, Petr ; Obruča, Stanislav (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The work was comprehensively focused on the development of adhesive forms of probiotics in the form of a biofilm on combined carriers with a prebiotic component. The second part dealed with the influence of food on the multiplication and survival of selected types of probiotic bacteria. Subsequently, the effect of individualized probiotic supplements on changes in the human intestinal microbiome was monitored. Suitable adherent probiotic strains for biofilm formation were selected and tested. Methods have been introduced and different variants of carriers for culturing and binding bacteria have been tested. In vitro experiments verified the stability of biofilm stucture and its resistance to low pH, bile and antibiotics in comparison with the planktonic cell form. The antimicrobial effect of probiotic strains in the form of a biofilm was studied. The cultivation of the multispecies biofilm on the combined carrier was optimized and the stability of the biofilm and the final viability of probiotic bacteria were confirmed. Furthermore, the influence of various foods and beverages on the viability of probiotic bacteria was evaluated with emphasis on the simulation of passage through the gastrointestinal tract. Both models, solutions with standardised concentrations of alcohol, sugar, salts, proteins or different pH and different types of real foods and beverages were tested. The effect of food and beverages was tested on monocultures of Lactobacillus acidophilus, Bifidobacterium breve and on probiotic capsules containing a mixed culture of probiotic microorganisms. The survival of probiotics in various food matrices in the simulated gastrointestinal tract was quantitatively different. We managed to define foods suitable for supporting the multiplication of probiotic bacteria. A separate part of the work was focused on the targeted modulation of the intestinal microbiome by individualized probiotics that were prepared on the basis of molecular biological analyzes of the intestinal microbiome aimed at detecting the percentage of lactobacilli, bifidobacteria and phylum Firmicutes and Bacteroidetes. Personalized probiotic supplementation confirmed the positive effect of this approach on microbiome changes, especially on the increase of the content of lactobacilli, bifidobacteria and the overall diversity of the microbiome.
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