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Influence of plasma activated water on fungal diseases
Moskvina, Anastasia ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
This bachelor thesis focuses on influence of plasma treated water on fungal diseases. The theoretical part is dedicated to plasma-liquid interactions, properties and application of plasma activated water and its influence on different microorganisms. Plasma activated water contains reactive oxygen species which cause inactivation of living cells, making it a potential sterilizer. The experimental part of this work compares the effectiveness of three plasma treated water preparation techniques. Dielectric barrier discharge system was used to activate water above its surface. For the under the surface activation, a two-electrode system of both alternating and direct current was used. Plasma treated water was then used to prepare a suspended mixture with Aspergillus niger spores. The latter was then cultivated on agar plates for 72 hours. The overall effect was evaluated in amounts of colony forming units. The experimentally obtained data was processed and discussed in the results and discussion section of the thesis. It was found that the underwater surface activation had more significant effect on mold deactivation, which corresponds with the information contained in the theoretical part. Although the effect of dielectric barrier discharge was not as promising, all three methods used led to a decrease of colony forming units in comparison to the non-treated control sample.
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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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