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Antimicrobial Activity Evaluation of Biocidal Surfaces with Resazurin Assay
Patakyová, Sylvia ; Viktorová,, Jitka (referee) ; Králová, Marcela (advisor)
This diploma thesis deals with the determination of antimicrobial activity of surfaces with biocidal effect using the resazurin test. The resazurin method of determination is a non-invasive colorimetric method with great potential for widespread use. However, its use so far has been limited as it is not included among standardized methods. The colorimetric method was used as a way to evaluate the effectiveness of immersion experiments using antimicrobial films and the bacterial strain Escherichia coli. The fluorescence intensity of the dye in the suspensions, which were affected by the individual foils, was captured by photographic recording and subsequently evaluated using image analysis. The measured and calculated values of the antimicrobial effect of three samples of active foils with different concentrations of the biocidal substance were compared with the results obtained in conditions with a smaller error rate (using plate-reader) and with the results obtained through a standardized method to demonstrate the relevance of the resazurin method and to assess the antimicrobial activity of studied surfaces.
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Microbiological Aspects of Infectious Diseases Therapy
Paterová, Pavla ; Buchta, Vladimír (advisor) ; Kolář, Milan (referee) ; Jílek, Petr (referee)
Background: The method of serum bactericidal assay represents an alternative possibility of optimization of anti-infectious therapy and administration of antibiotics. It mirrors the real activity of one or more administered antibiotics in the complex system of the antibacterial effect of patient's serum. The paper aimed to confirm non-inferiority of bactericidal testing using the broth dilution method according to CLSI M21-A Guidelines (time to results 48, 72 hours) in comparison with modified methods of testing on the basis of turbidimetry (time to result 6, 8, 24 hours) and resazurin color (time to results 8, 24 hours). Methods: Four antibiotics were tested: gentamicin, amikacin, piperacillin/tazobactam and meropenem with 30 Escherichia coli strains isolated from blood cultures of 29 pacients hospitalised in different wards, University Hospital in Hradec Kralove. Human blood sera (n = 76) from ten hematological patients (4th Department of Clinical Medicine, University Hospital, Hradec Kralove) were tested to establish bactericidal titer. Patients' blood was withdrawn prior to and in the course of the first and third day of antibiotic therapy of febrile neutropenia. Testing employed the reference strain Escherichia coli ATCC 25922. Results: A comparison with the standard CSLI showed that the...
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Methods for viability evaluation of Xanthomonas vesicatoria after low temperature plasma treatment
ZEMANOVÁ, Marta
The thesis deals with methods for viability evaluation of the phytopathogenic bacterium Xanthomonas euvesicatoria after low-temperature plasma treatment. Low-temperature plasma produced by Gliding Arc experimental device was used for treatment of X. euvesicatoria. The viability of the bacterial cells was assessed using a scanning electron microscope (SEM) and by measuring of the fluorescence in the Smart-DART device using PrestoBlue chemical reagent. Methodology has been optimised for the sample preparation for the treatment by low temperature plasma and used for evaluation of applied methods. Lethal effect of gliding arc plasma to this gram-negative bacteria was verified by SEM which showed. There is significant structural changes on the cell surface. Viability assessment of X. euvesicatoria using Smart-DART device is a fast, time-saving and inexpensive evaluation of cell viability. The great advantage of this device is its ability to measure the fluorescence in real time. The disadvantage of this method is lower reliability in current stage of research.
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Monitoring of phytopathogenic bacteria viability after low-temperature plasma treatment
ZEMANOVÁ, Marta
The bachelor´s thesis is focused on the monitoring of phytopathogenic bacteria´s viability after low-temperature plasma treatment. Gliding Arc device has been used for the plasma treatment of phytopathogenic bacteria. Evaluation was carried out using chemical reagent PrestoBlue which was followed by spectrophotometric evaluation and calculating CFU/ml from the regression equation derived from the calibration curve. The effect of the low-temperature plasma on the viability of plant pathogenic bacteria was prooved. Gram-negative bacteria Erwinia amylovora and Rahnella aquatilis were the most susceptible to the plasma treatment. These phytopathogenic bacteria belong to the family Enterobacteriaceae. Representatives of gram-positive bacteria showed lower sensitivity to the low-temperature plasma treatment. Suitable method has also been designed for the treatment of phytopathogenic bacteria by the low-temperature plasma at atmospheric pressure.
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