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Impact of plasma-treated liquids on selected microorganisms
Klementová, Kamila ; Jirásek, Vít (referee) ; Trebulová, Kristína (advisor)
The subject of this bachelor thesis is the study of the effects of plasma-treated liquids on bacteria Staphylococcus aureus and Pseudomonas aeruginosa. The evolving resistance of bacteria against antibiotics is currently a highly debated topic. Plasma treated liquids have the potential to address this problem due to their antimicrobial effects. However, these effects have not yet been fully explained, therefore they are the focus of this work. The theoretical section of the study is mainly focused on the microbiology part, specifically on the morphology of the bacterial cell and the individual bacteria which was used in the experimental section. Furthermore, plasma, cold atmospheric-pressure plasma (CAP) and plasma-liquid interactions are described. The last part of the theoretical section considers the potential applications of cold plasma and plasma-treated liquids (PTL) in the fields of food and agricultural industry and healthcare. In the experimental section, plasma-treated liquids were prepared from saline solution using two plasma systems. Solutions simulating the composition of the prepared PTL, and standard solutions of nitrites, nitrates and hydrogen peroxide were also prepared. The effects of plasma-treated liquids were compared with those of solutions simulating the composition of plasma-treated liquids and with standard solutions. The effects were tested on standardized bacterial cultures of Staphylococcus aureus and Pseudomonas aeruginosa. Their suspensions were exposed to the plasma-treated liquids, prepared standard solutions and PTL alternatives. At the selected exposure times, the number of viable bacteria was determined by inoculation onto the solid culture medium and after 24 hours of incubation, the antimicrobial effects were evaluated by counting colony forming units using Aurora software. The results of this study proved better antimicrobial efficacy of plasma-treated liquids compared to the solutions simulating their composition. There was a difference in the effects between the two plasma-treated liquids that were tested. Pseudomonas aeruginosa was also shown to be more susceptible to plasma-treated liquids than Staphylococcus aureus.
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Study of the antimicrobial effects of selected spices
Kalábová, Jana ; RNDr.Eva Dvořáčková (referee) ; Voběrková, Stanislava (advisor)
The antimicrobial effects of cinnamon, clove and ginger (grand and fresh) extracts against Bacillus subtilis, Aspergillus niger and Pichia fermentans were studied in this thesis. Selected spices were extracted in three solvents (ethanol, water and ethyl acetate) and inhibition effect on tested microorganisms was studied using two methods disc diffusion and broth dilution methods. The antioxidant activity and total polyphenolic compounds from spices were also determined. The results showed that cinnamon and clove extracts in ethyl acetate and ethanol were a promising antimicrobial substances for all tested microorganisms. Combination of cinnamon and clove especially ethyl acetate extracts showed an aditive effect. However, in the case of broth dilution method, fresh ginger inhibited bacterial growth under optimal growth conditions of Bacillus subtilis (35 °C, pH 7, 250 rpm). Minimum inhibitory concentration (MIC) values for all susceptible microorganisms was determined 8,3 mg/ml. The highest amounts of polyphenolic substances were found in cinnamon and clove ethanol extract and this result was in correlation with antioxidant activity.
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Silver based raw materials for cosmetic purposes
Čaková, Adriana ; Ďubašáková, Mária (referee) ; Zemanová, Jana (advisor)
The purpose of this bachelor’s thesis was a research about silver based cosmetic products and determination of antimicrobial activity on certain species of microorganisms by chosen silver based cosmetic products. Theoretical part is focused on the problematics of silver based cosmetic products, on their main purpose, physically chemical characteristics and toxicological profile. In the theoretical part is also mentioned problematics of legislative, mainly the safety and real effectivity of tested cosmetic products. Experimental part was focused on determination of antimicrobial activity of chosen silver based cosmetic products. Two silver based cosmetic product were used to determined antimicrobial activity on selected microorganisms Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Kocuria rosea, Serratia marcescens a Candida vini. From result it is apparent, that both of used Cosmetic product showed antimicrobial activity, but not on every used microorganism.
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Biological effects of various hemp fractions
Vacková, Hana ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Cannabis is the only plant which contains cannabinoids and thanks to these compounds it has enormous potential. This thesis deals with the analysis of technical hemp. Effects of cannabinoids and methods used for cannabis analysis are discussed in the theoretical part. The experimental part includes spectrophotometric characterization of cannabis, it´s antimicrobial effects and thin layer chromatography analysis. Three sorts of Cannabis sativa L. were analyzed, namely Finola, Fedora and Kompolti. Firstly, the content of polyphenols, flavonoids and antioxidant activity in prepared tinctures were determined. Moreover, antimicrobial test were performed using disk test and turbidity determination. Gram-positive and Gram-negative bacteria and yeast organism were tested. It was found that cannabis tinctures possess good antimicrobial effects. Some of them are comparable with synthetic antibiotics. Finally, thin layer chromatography enabled visualization of cannabinoids in prepared tinctures.
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Liposomal forms of drugs for the treatment of lung diseases caused by selected types of bacteria
Janoušková, Vendula ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This diploma thesis deals with the study of the encapsulation efficiency of the antibiotic doxycycline encapsulated in the individual liposomal systems depending on different composition of the components. We also discussed the kinetics of the encapsulated drug releasing from the carrier systems. The liposomal systems for the treatment of local lung diseases were selected due to their suitable physicochemical properties. The bacterium called Staphylococcus aureus was chosen as a model of the local lung disease, pulmonary pneumonia. Doxycycline was chosen as the antibiotic ideal for the treatment of staphylococcal infection. The aim of the diploma thesis was to optimize the composition of liposomes which would have application potential for the inhalation administration of drugs. Two suitable liposomal systems have been prepared consisting of the addition of various components as cholesterol and phosphatidic acid. We have succeeded in determination of the drug concentration for the encapsulation which had sufficient antimicrobial efficacy to treat the local lung disease. The cytotoxic tests were used to determine the side effects of selected liposomal systems. Furthermore, the individual liposomal systems were characterized in terms of size, zeta potential and kinetic stability which are other important properties effecting their future application potential.
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Study of plasma and plasma activated water effect for bacterial disease treatment
Korečková, Svatava ; Jirásek,, Vít (referee) ; Kozáková, Zdenka (advisor)
The aim of this master thesis was to prepare plasma-treated liquids (PTL), specifically plasma-treated saline solutions, using different plasma systems. Subsequently, PTL was applies onto selected microorganisms to determine its antimicrobial effect. Systems that use both direct and indirect plasma-liquid interactions were selected, and the plasma was generated at atmospheric pressure. The theoretical part is focused on the plasma treated water, the systems by which PTL can be produced, and a description of the characterization process, from the viewpoint of the amount of active particles or the physical-chemical properties. Here, the microbiological part of this work is also included, namely a description of the microorganisms used for the experimental part. The disease of otitis externa (inflammation of the external auditory canal) and the possibilities of its antibiotic treatment are also described here. In this work, PTL prepared by four different plasma systems were tested: the pinhole discharge with DC or AC high voltage source (PTLAC and PTLDC), the liquid electrode dielectric barrier discharge (PTLDBD), and the microwave surface wave discharge (PTLSW). Prepared PTLs were first characterized in terms of reactive particles (hydrogen peroxide, nitrates and nitrites) and changes in specific conductivity and pH. This was followed by microbiological testing of the antimicrobial efficiency of the prepared PTL. The bacteria Staphylococcus pseudintermedius, Pseudomonas aeruginosa and the yeast Malassezia pachydermatis were selected as test microorganisms. These microorganisms were exposed to PTL and the effects were studied for exposure times from 1 minute to 4 hours. After 24 hours of cultivation, the antimicrobial effects were evaluated by the standard plate count method and also by the image analysis method in the software Aurora. The next step was to compile antibiograms and compare the effect of the prepared PTL in different systems with the effect of antibiotics. In this master thesis, it was proven that the bacterium Pseudomonas aeruginosa is resistant to several antibiotics. Thus, the prepared PTLDC could represent the possibility of its inactivation without the use of antibiotics. Staphylococcus pseudintermedius and Malassezia pachydermatis do not have resistance to any antibiotic (antimycotic), but with incorrect use there is a risk of developing resistance, which is why PTL, with the highest antimicrobial effect, were also found for these microorganisms.
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USE OF COMPLEX EXTRACTS FROM PLANT AND MICROORGANISMS IN FOODS AND COSMETICS
Uhlířová, Renata ; Kovalčík, Adriána (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on optimalization of preparation of extracts of various origin (plant and microbial). The influence of extraction agent, disintegration of microbial cells as well as special techniques for enhancement of extraction process effectiveness (ultrasound and microwaves) were monitored. As part of the characterization, considering the source material, the composition of the prepared extracts was analyzed both spectrophotometrically and using liquid and gas chromatography. The most suitable extraction procedure varies depending on the type of material. For herbal samples, the highest content of active substances was achieved when the extraction facilitated by microwaves was used. Contrarily, the optimal method for cyanobacteria is the traditional extraction method, which is carried out for 24 hours at laboratory temperature. The most suitable method for extracting the active substances from yeast was a combination of DMSO, ethanol and hexane. Further, the effect of extracts on microbial cultures of bacteria (E. coli, S. epidermidis, C. acnes) and yeast (C. glabrata) was observed. For cytotoxicity evaluation MTT and LDH assays were performed on HaCaT and Caco2 human cell lines. The antimicrobial tests have demonstrated the antimicrobial, antibacterial and antifungal effect of a numerous extracts, especially the essential oils of Lavandula angustifolia and Mentha piperita. On the other hand, the cytotoxicity tests showed that the most of the extracts were safe for the use in the food industry and cosmetics within a range of up to 10% by volume. To improve stability, the prepared extracts were enclosed into liposomal particles enriched with PHB polymer (0–100%). Using a ZeteSizer NanoZS device, the particles' size, polydispersity index, and colloidal stability were assessed. The cryoTEM was used to examine the particle´s morphology. Liposomes and liposomes with the addition of 20 % PHB (PHB20) were evaluated as the most suitable particles for encapsulation of the prepared extracts. Excellent stability and high encapsulation efficiency were displayed by the produced particles. Genotoxicity testing with SOS chromotest on the model organism E. coli did not reveal any genotoxic effects. As an alternative method to achieve stabilization of active substances, nanofibers from PHB were prepared by three different techniques and gelatin nanofibers by electrospinning. The fibers were monitored for their diameter, uniformity, distribution on the collector using SEM and the gradual release of active substances from the fiber structure. The evaluations revealed that the forcespinning and electrospinning techniques were the most appropriate for further investigation. A continuous release of active ingredients was achieved by incorporating extracts into nanofibers. Several applications of prepared materials in the food industry and cosmetics were designed and developed as part of this work. The base emulsion's stability and general qualities were improved when green coffee and carotenogenic yeast extracts were added. The usage of emulsions containing coffee and yeast extracts would be suitable as sunscreens, and after the addition of Spirulina extract, as day or night anti-wrinkle creams. Energy drinks of the new type based on coffee with the addition of encapsulated plant extracts enable gradual release of caffeine and antioxidants during digestion.
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Testování antimikrobiální aktivity obalových materiálů s rostlinnými extrakty proti bakteriím rodu Enterococcus
Maňáková, Simona
This thesis deals with testing of antimicrobial activity of plant essential oils as part of packaging systems for foodpackaging against bacteria genus Enterococcus. The first literature part is focused on characteristic of genus Enterococcus and his possible apperace in food and his negative effect on human health. Next topic of literature section is targeted on using plants as producers of essential oils and their use in food industry as active compounds with antimicrobial and atifugal activity. This includes also characteristic of selected aromatic plants growing in our geographical conditions. Last part of literature section is introduction of characteristic of packaging materials and theirs big importance in food industry. Practical part of this thesis is dealing with testing of packaging materials containg essential oils on theirs surface against E. faecalis. Another part of this experiment is testing these antimicrobial packaging materials on selected foods in this case meat product following with microbiological analysis of selected bacteria.
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Silver based raw materials for cosmetic purposes
Čaková, Adriana ; Ďubašáková, Mária (referee) ; Zemanová, Jana (advisor)
The purpose of this bachelor’s thesis was a research about silver based cosmetic products and determination of antimicrobial activity on certain species of microorganisms by chosen silver based cosmetic products. Theoretical part is focused on the problematics of silver based cosmetic products, on their main purpose, physically chemical characteristics and toxicological profile. In the theoretical part is also mentioned problematics of legislative, mainly the safety and real effectivity of tested cosmetic products. Experimental part was focused on determination of antimicrobial activity of chosen silver based cosmetic products. Two silver based cosmetic product were used to determined antimicrobial activity on selected microorganisms Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Kocuria rosea, Serratia marcescens a Candida vini. From result it is apparent, that both of used Cosmetic product showed antimicrobial activity, but not on every used microorganism.
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Studie antimikrobiálního účinku včelího jedu na druhy borelie z komplexu \kur{B. burgdorferi} sensu lato: izolace genu kódujícího antimikrobiální peptid melitin z jedové žlázy včely medonosné \kur{(Apis mellifera)}
DAVIDOVÁ, Marie
The incidence of tick borne diseases has drastically increased over the past few years. Control of tick borne pathogens, especially spirochetes from \kur{B. bugdorferi} sensu lato complex, is complicated due to a lack of vaccines against them. The emergence of bacterial strains to well established and widely used antibiotics has become a serious public health concern. Analysis of new classes of antimicrobial peptides became the subject of new investigation due to their efficacy against disease causing pathogens. Among possible candidates, melittin from honey bee venom is of particular interest. The aim of this work was to study the effect of whole bee venom on Lyme borreliosis spirochetes. The minimum concentration of the venom that possesed the inhibitory effect on borrelia growth was identified. The gene enconding melittin was isolated from bee venom gland and recombinant melittin was produced in bacterial expression system. The effect of recombinant melittin on live borrelia culture was studied.
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