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Study of plasma interaction with yeast Candida glabrata
Trebulová, Kristína ; Lehocký, Marián (referee) ; Krčma, František (advisor)
The main subject of this diploma thesis is the study of low temperature discharges´ effects on the yeast Candida glabrata (C. glabrata). Cold atmospheric-pressure plasma (CAPP) technology has achieved a great deal of attention in recent years, due to its positive attributes, including high efficiency against a wide range of microorganisms, ease of operation, economic simplicity and also environmental friendliness. The research of CAPP focuses mainly on the applications involving the treatment of cancer and superficial infections as well as sterilization technologies in medicine, food and agriculture. Various effects and also some mechanisms of inactivation of bacteria and tumor cells have been explained over the last decade but the effects and mechanisms of fungi inactivation have not yet been sufficiently investigated. The aim of this work is to verify the effects of chosen low-temperature discharges on the model yeast example C. glabrata, in order to establish basic plasma set-up for further studies and experiments in vivo and to expand a global knowledge about the antifungal effects of CAPP. In this study, 5 different discharges, namely: microwave (unipolar and surface wave) in the form of plasma torch, transient spark, corona discharge in the form of corona pen and dielectric barriere discharge (DBD) in the form of DBD pen were tested. All discharges were tested by direct application onto a 24-hour inoculum of C. glabrata inoculated on agar plates. The results were evaluated based on the size and stability of the inhibition zones formed in the post treatment cultivation. From the individual measurements optimal conditions for testing the inhibitory effects of low temperature discharges on the selected yeast were determined. The microwave discharges (unipolar and surface wave) were chosen to be the most effective in the inhibition of C. glabrata. The measurements were therefore pursued with these discharges under selected conditions corresponding to chosen application of sterilization of surface infections in living organisms. The unipolar microwave discharge was chosen to be the most effective discharge for the potential treatment of superficial candidiasis. The indirect effect of plasma was also investigated using plasma activated liquid (PAL) on inoculated yeast culture. PAL was prepared using 3 different discharges: Dielectric Barrier Discharge (DBD), Unipolar Microwave Discharge and Electric Discharge in Liquid. The results of this work prove significant inhibitory effects of CAPP on the yeast C. glabrata, within the limits of in vitro cultivation and the so-called flat biology. The overall inhibitory effects are directly proportional to the irradiation time, the magnitude of applied power and also the area covered by the discharge. In terms of the initial cell concentration an indirect dependency can be observed, but it can also be stated that this factor is less significant compared to the other examined factors. Observations of the effects of plasma activated liquid (PAL) indicate that a single application of PAL under selected conditions is not alone enough for successful inhibition of C. glabrata.
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Optimization of distribution of active particles generated by low temperature plasma on biopolymer surfaces
Krupičková, Lucie ; Kozáková, Zdenka (referee) ; Krčma, František (advisor)
This thesis is focused on the optimization of the distribution of active particles (RONS), generated by the low temperature plasma, on the biopolymer surfaces. The theoretical part characterizes plasma and its active particles. Furthermore, this chapter summarizes its applications in medicine and food industry, also a review of different skin models is listed here. The last section is focused on the skin anatomy and the characterization of selected microorganisms C. glabrata, E. coli and S. epidermidis. In the experimental part, selected biopolymers with specific dyes for detection of active particles were prepared. Furthermore biopolymers were spot treated under different conditions leading to color changes in all biopolymers. This test confirmed a presence of active particles in the plasma. After that, the optimal parameters for active particles distribution over the entire surface were found. Also an experiment, which allowed the UV light to pass through but prohibited the passage of active particles, was made. In this experiment, no color change was noticed, which means, that the reaction of active particles with the colored biopolymer is responsible for the color change. The optimized parameters were used for treatment of agar plates with monoculture of C. glabrata, E. coli, S. epidermidis and with mixed culture C. glabrata + E. coli. Two different plasma torches were used – unipolar microwave discharge torch and surface wave microwave discharge jet. Treated samples were photographed after incubation. Software Aurora then calculated the surface area which was covered by the microbial culture. Based on the data, the microbial reducion was evaluated in comparison with untreated samples. The unipolar microwave discharge torch achieved higher efficiency than the surface wave microwave discharge jet, for all tested microorganisms.
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Application of plasma and plasma activates water for wound healing
Šrámková, Sarah ; Janda,, Mário (referee) ; Kozáková, Zdenka (advisor)
This work is focused on the study of plasma interactions with liquids and selected microorganisms, Staphylococcus epidermidis and Escherichia coli. The use of the cold atmospheric pressure plasma in the biomedical field has been a hot topic in the last decade, due to its decontamination properties applicable not only in the biomedical field but also in the food industry and agriculture. Recently, the plasma treated (activated) liquids (PTLs) have also been a subject of a great interest due to the relatively simple preparation, the possibility of optimizing the composition of PTLs to achieve the desired effect, their non-toxic nature and their environmental friendliness. The purpose of this work is to study the inhibitory effects of the plasma discharges and the plasma treated liquids for the purpose of decontamination and stimulation of wound healing. To study the effect of a direct plasma application on selected microorganisms, two types of discharges, the unipolar microwave torch and the microwave surface wave jet, were selected. For both selected discharges, the dependence of the inhibitory effects on the treatment time, the power, the closure of the treated area and the bacterial species (gramnegative/grampositive) was studied. Comparable results in the inhibition efficiency were obtained for both discharges. The effect of indirect treatment using plasma-treated water was studied next. A decent microbial reduction occurred for all three studied PTLs. The PTL prepared using a plasma jet with a direct current (DC) source was found to be the most efficient. The last stated goal of this diploma thesis was to study the effect of treatment combinig both the indirect treatment with PTL and the direct plasma treatment. Based on the results of previous treatments, a bacterial culture of Staphylococcus epidermidis was treated with PTL prepared with a direct current (DC) plasma jet. The unipolar microwave torch with a power of 12 W was selected for the direct treatment. By combining both types of treatments, higher inhibition effeciency was achieved. The inhibition efficiency was demonstrated for all types of treatments, with the combined treatment aspiring to be the most effective, as it targets both grampositive and gramnegative bacteria.
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Study of plasma interaction with yeast Candida glabrata
Trebulová, Kristína ; Lehocký, Marián (referee) ; Krčma, František (advisor)
The main subject of this diploma thesis is the study of low temperature discharges´ effects on the yeast Candida glabrata (C. glabrata). Cold atmospheric-pressure plasma (CAPP) technology has achieved a great deal of attention in recent years, due to its positive attributes, including high efficiency against a wide range of microorganisms, ease of operation, economic simplicity and also environmental friendliness. The research of CAPP focuses mainly on the applications involving the treatment of cancer and superficial infections as well as sterilization technologies in medicine, food and agriculture. Various effects and also some mechanisms of inactivation of bacteria and tumor cells have been explained over the last decade but the effects and mechanisms of fungi inactivation have not yet been sufficiently investigated. The aim of this work is to verify the effects of chosen low-temperature discharges on the model yeast example C. glabrata, in order to establish basic plasma set-up for further studies and experiments in vivo and to expand a global knowledge about the antifungal effects of CAPP. In this study, 5 different discharges, namely: microwave (unipolar and surface wave) in the form of plasma torch, transient spark, corona discharge in the form of corona pen and dielectric barriere discharge (DBD) in the form of DBD pen were tested. All discharges were tested by direct application onto a 24-hour inoculum of C. glabrata inoculated on agar plates. The results were evaluated based on the size and stability of the inhibition zones formed in the post treatment cultivation. From the individual measurements optimal conditions for testing the inhibitory effects of low temperature discharges on the selected yeast were determined. The microwave discharges (unipolar and surface wave) were chosen to be the most effective in the inhibition of C. glabrata. The measurements were therefore pursued with these discharges under selected conditions corresponding to chosen application of sterilization of surface infections in living organisms. The unipolar microwave discharge was chosen to be the most effective discharge for the potential treatment of superficial candidiasis. The indirect effect of plasma was also investigated using plasma activated liquid (PAL) on inoculated yeast culture. PAL was prepared using 3 different discharges: Dielectric Barrier Discharge (DBD), Unipolar Microwave Discharge and Electric Discharge in Liquid. The results of this work prove significant inhibitory effects of CAPP on the yeast C. glabrata, within the limits of in vitro cultivation and the so-called flat biology. The overall inhibitory effects are directly proportional to the irradiation time, the magnitude of applied power and also the area covered by the discharge. In terms of the initial cell concentration an indirect dependency can be observed, but it can also be stated that this factor is less significant compared to the other examined factors. Observations of the effects of plasma activated liquid (PAL) indicate that a single application of PAL under selected conditions is not alone enough for successful inhibition of C. glabrata.
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