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Molecular genetic characterization of vancomycin-resistant enterococci
Bubeníček, Karel ; Rada, Vojtěch (advisor) ; Igor, Igor (referee)
Summary
Objectives and hypothesis: This thesis concerns the study of plasmids of vancomycin-
resistant enterococci isolated from feces of American crows in the years 2012 - 2013 period.
The hypothesis is that, in various environments, there is one or more types of
epidemiologically significant vanA gene-carrying plasmids that are capable of horizontally
spread.
Methods: Based on PFGE method the number and size of plasmids were detected in selected
isolates of vancomycin-resistant E. faecium. Using PCR method the isolates were subjected
to detection of genes of replicases, relaxases and toxin-antitoxin system of plasmid-bound
resistance genes. Using 19 primers were characterized types of Tn1546.
Results: Of the 12 tested vancomycin-resistant isolates of E. faecium the following number
and size of plasmids was proven using PFGE method: 2 isolates contained two plasmids
(17%), 3 isolates contained three plasmids (25 %), 5 isolates contained four plasmids (42 %)
and 2 isolates contained five plasmids (17 %).
All isolates (n = 12) were then subjected to the detection of genes of replicases, relaxases and
toxin-antitoxin system for typing of plasmids from each plasmid families.
RepA_N family of plasmids:
genes characterizing plasmids related to pRUM: rep17 in 11 isolates (92 %),
gene Axe-Txe was detected in 5 isolates (42 %)
genes characterizing plasmids related to pLG1: rep20 in 7 isolates (58 %)
genes characterizing plasmids related to pAD1: relpAD1 gene was detected in one isolate (8 %)
Inc18 family of plasmids:
genes characterizing plasmids related to pIL501: rep1 gene detected in one case (8 %)
genes characterizing plasmids related to pRES25: rep2 gene in 2 isolates (17 %)
genes characterizing plasmids related to pEF1: relpEF1 detected in 11 isolates (92 %)
pHTB family of plasmids:
genes characterizing plasmids related to pHTB: rep22 gene was detected in 4 isolates (33%) and in 2 isolates gene relpHTB was detected (17%)
RCR family of plasmids:
genes characterizing plasmids related to pRI: positive detection of Rep14 gene in 8 isolates (67%) and in 4 isolates relpRI gene was detected
Small theta-replicating plasmids:
genes characterizing plasmids related to pEF418 plasmids: rep18a gene in 2 isolates (17%)
genes characterizing plasmids related to pB82: rep18b gene was detected in one isolate (8%)
genes characterizing plasmids related to pCIZ2: relpCIZ2 gene was detected in 9 isolates tested (75%)
Types of transposon Tn1546
Using the PCR method types of Tn1546 were characterized. In 4 isolates (n = 12; 33 %)
Tn1546 was characterized as a F3 type. In one isolate (8 %) Tn1546 was characterized as a
type F5, in one isolate (8 %) as a type PP-16. In 6 isolates Tn1546 was untypeable. Most
likely these are new, yet unknown types.
Conclusion: This is the first study of plasmids of vancomycin-resistant isolates E. faecium
isolated from feces of American crows. These results emphasize not only a high proportion of
plasmids in individual isolates, but also a high proportion of genes with horizontal transfer.
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Impact of pesticides on the gut microbiota of human
Kočová, Kateřina ; Rada, Vojtěch (advisor) ; Jakub, Jakub (referee)
Pesticides are substances or mixtures of substances used in agriculture against pests (animals, plants and parasitic fungi), who damage the crops, stocks of agricultural products, food and reduce livestock utility or threaten human health.
The thesis consists of two parts. The first (theoretical) part describes composition and function of gut microbiota; pesticides and their classification, environmental transport and effects of these substances on human health, and glyphosate as the active substance of herbicide Roundup, its mechanism of action, environmental fate and proven effects of glyphosate on human.
The aim of second (practical) part of this thesis was to test impact of pesticide Roundup on the gut microorganisms of human. The impact of pesticide was tested in in vitro pure cultures. Roundup was added in concentrations of glyphosate 17 g/L, 1,7 g/L and
0,17 g/L to the complex media and after cultivation the growth of microorganisms was evaluated. The next samples of stool were collected from human volunteers; these were cultivated similarly in the complex media with different concentrations of glyphosate. The total numbers of microorganisms, bifidobacteria, lactobacilli, enterococci and coliformn bacteria were defined after cultivation.
When the pesticide was tested in pure cultures, concentration of 17 g/L glyphosate significantly inhibited total bacterial growth (P < 0.05), at lower concentrations no difference was observed. The cultivated microorganisms from samples of stool demonstrated only that bifidobacteria are sensitive to glyphosate at the highest used concentration of this pesticide compared with the control sample.
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Clostridium butyricum as a probioticum
Veselá, Jana ; Rada, Vojtěch (advisor) ; Pechar, Radko (referee)
Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Evidence of positive effects of probiotics is rapidly expanding in gastroenterology. Probiotics find use in antibiotic-associated diarrhea, gastroenteritis and lactose intolerance.
Many different strains of bacteria are considered as probiotic, including clostridia. The most used probiotics are Lactobacillus and Bifidobacterium species. But there are also suggestions that some Clostrium butyricum strains could be also probiotic.
Aim of this study was therefore to evaluate the effectiveness of Miya-Gold (a feed additive containing viable spores of probiotic Clostridium butyricum MIYAIRI 588 strain as an active substance) to the improvement of feed conversion, average daily gain and final body weight in the chickens for fattening and also to observe the improvement of the stability of the gut and crop microbiota.
We found statistically significantly higher (P < 0.05) average weights of individuals in Miya-Gold group than in the control group at the day 7, 10, 20 and 49. By the analysis of microbiota we found at the day 42 statistically significantly lower (P < 0.05) amounts of Escherichia coli in the caecum and Escherichia coli and coliform bacteria in the crop and also lower pH in the crop in the Miya-Gold group.
The analysis of short-chain fatty acids was also performed and we found statistically significantly higher (P < 0.05) amount of butyrate in the caecum of Miya-Gold group.
The results indicate the ability of Miya-Gold to affect positively the performance and the intestinal microbiota of broiler chickens.
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Výroba energie z obnovitelných zdrojů jako forma diverzifikace činnosti zemědělského podniku
Rada, Vojtěch
This thesis deals with renewable energy sources with a focus on the biogas plant as a new form of diversification of farm activities. In the theses is characterized renewable energy source of energy, their development and tools for their support in the European Union and the Czech Republic. At the same time provides the legislative framework for the support of renewable energy sources. Describes the development of biogas plants in the Czech Republic, lists the various types of biogas plants, the principles of their operationn and types of purchase of electricity. The work focuses on the characterization and comparison of two technologically different biogas plants for two years, which are operated in farms. These biogass plants compares between each other by analysis of the costs and revenues related to the production of electricity. At the same time, the thesis analyzed the external and internal environment of these biogas plants
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CHARAKTERIZACE NOVÝCH DRUHŮ LAKTOBACILŮ A JINÝCH BAKTERIÍ MLÉČNÉHO KVAŠENÍ Z TRÁVICÍHO TRAKTU SAVCŮ A HMYZU
Killer, Jiří ; Kopečný, Jan ; Mrázek, Jakub ; Koppová, Ingrid ; Rada, V. ; Kott, T.
Do skupiny probiotik, která jsou zjednodušeně definována jako „potravní doplňky obsahující přesně definované ţivé mikroorganismy mající prokazatelně pozitivní vliv na zdraví hostitele a zlepšující navíc vyuţívání ţivin“, náleţí především kmeny bifidobakterií, laktobacilů a jiných bakterií mléčného kvašení (druhy r. Lactococcus, Enterococcus, Streptococcus), ale také nepatogenní druhy bacilů (např. Bacillus coagulans), dále nepatogenní Escherichia coli, Propionibacterium freudenreichii a eukaryota v podobě některých druhů kvasinek (Saccharomyces boulardi). Zdá se, ţe výzkum probiotik je v současné době zaměřen na jiţ známé druhy především laktobacilů a bifidobakterií. Vzrůstá tedy význam testování probiotických vlastností jiných druhů bifidobakterií a bakterií mléčného kvašení (dále BMK), stejně tak izolace dosud nepopsaných druhů potenciálně vyuţitelných nejen v humánní medicíně, ale také v chovech hospodářských zvířat a v chovech hospodářsky významného hmyzu (včel a čmeláků).
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Solution of soil protection from erosion in model catchment - Malče Budský stream.
RADA, Václav
The aim of this thesis is to assess and evaluate the erosion phenomena at the model catchment of Malče Budský stream. This site is located on the cadastral areas Besednice, Soběnov and Malče. This survey was conducted in aspects of pedology, hydrogeology and climate. Further evaluations were rain amount for the nearest meteorological station, which is located in Soběnov. To evaluate and calculate erosion parameters for a given locality the methods of universal soil loss equation by Wishmeier and Smith and modified universal soil loss equation by Williams and Berndt have been used. The CN method was used for calculations and following evaluation of soil loss. The result of this thesis is designing, generalization and refinement of individual factors in solved area.
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