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Study of interactions of quorum sensing with yeasts I.
Macková, Jitka ; Buchta, Vladimír (advisor) ; Voxová, Barbora (referee)
Author: Jitka Macková Title: Study of interactions of quorum sensing with yeasts. Part I Diploma thesis Charles University in Prague, Faculty Of Pharmacy in Hradec Králové Study programme: Pharmacy Background: The aim of the work is to sum up findings about quorum sensing in Candida albicans communication. The quorum sensing effects were studied on farnesol on model of conversion of blastospores into germ tubes in C. albicans. Methods: Four strains of C. albicans were tested, two of them were from American Type Culture Collection and two were obtained from the pacients suffering from vulvovaginal candidosis. The method of germ tube test was standardized to evaluate the farnesol effects on germ tube induction including the possibility for testing effects of preincubation in presence or absence of farnesol. Results: There was no significant difference in the production of germ tubes between Sabouraud glucose agar and YPD medium used for the preparation of inoculum. The chemically defined medium NYP provided more consistent results than bovine serum in terms of germ tube induction if the cell density of a yeast was 106 cfu/ml. It is better to hold experiments in test tubes made of glass than plastic. Experiments with farnesol showed that germ tube inhibition was strain-dependent. Preincubation with...
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The evaluation of in vitro activity of potentially antifungal compounds by microdilution broth method. VIII.
Kvítková, Lenka ; Buchta, Vladimír (advisor) ; Doležal, Martin (referee)
Kvítková L.: Evaluation of in vitro activity of potentially antifungal compounds by microdilution broth method - VIII. Over 250 new synthetized compounds divided into 16 chemical groups were tested by microdilution broth method for the establisment of in vitro antifungal activity. This method is based on the standard M27-A (Clinical Laboratory Standard Institute). RPMI 1640 medium buffered to pH 7.0 with MOPS was used and standardized inoculum was prepared from fresh fungal isolates grown on Sabouraud agar. All compounds tested were dissolved and diluted in DMSO. The MICs were determinated visually after 24 or 48 hours of incubation at 35C. The compounds were tested against eight fungal strains. The structure-activity relationships were studied and compared with the calculated log P values. Hydrophobicity of compounds (log P) was computed using the program ACD/LogP (Advanced Chemistry Development Inc., Ontario, Canada). The most active compounds were the derivatives of (E)-1-pyrazine-2- ylethane-1-one-thiosemicarbazone; the majority of the compounds showed moderate or high efficacy against all fungal strains tested. There were several compounds of the groups tested with a considerable antifungal effect, as well. The most susceptible fungal strain was Trichophyton mentagrophytes, on the contrary,...
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Use of blood culture system BacT/Alert for detection of bacteria present on the surface of vascular catheters.
Klementová, Michaela ; Buchta, Vladimír (advisor) ; Ryšková, Olga (referee)
Klementová M.: Use of blood culture system BacT/Alert for detection of bacteria present on the surface of vascular catheters. The number of bacteria present on the surface of vascular catheters was set with the method of quantitative cultivation of vascular catheters by means of blood culture system BacT/Alert on the basis of TTD. The results were compared with the clinical condition of the patient and classical hemocultures. A total number of 171 vascular catheters was examined with this new method. Positive cultures were detected in 15 (8,8 %) catheters. According to the results of microbiological catheter examination with clinical condition of the patient was found in 94,7 %. False positivity occurred in 2,3 % and false negativity in 2,9 % of cases. On the basis of clinical symptoms 16 cases of catheter sepsis were diagnosed out of which 11 (68,7 %) positive microbiological quantitative examinations of vascular catheters were established. The most frequent pathogen was coagulase negative staphylococci. The new method, when compared with present methods, is simpler, faster and able to detect the most frequent agent of catheter infection.
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Use of blood culture system Bactec for detection of bacteria present on the surface of vascular catheters.
Schwarzerová, Andrea ; Buchta, Vladimír (advisor) ; Ryšková, Olga (referee)
OF THESIS SCHWARZEROVÁ, A. The use of hemoculture Bactec for detection of bacteria present on the surface of vascular catheters. Hradec Králové: Department of biological and medical sciences, College of Pharmacy UK, 2007, 60 p. Thesis, Čermák, P. Objective: The objective of this thesis was to rewiew the use of hemoculturel system Bactec for detecting the amount of bacteria present on the surface of the vascular catheters and to copare the results of the cultivated bacteria with the clinical condition of the patient. The method: The method is based on shaking the catheter in physiological solution. The physiological solution with the bacteria from the catheter was added to hemoculturel bottle Bactec Standard Aerobic. The Quantity of bacteria was based on TTD (time to detection). The Border value was 103 bacteria for diagnosing catheter sepsis. Conclusion: This method of diagnosing catheter sepsis is fast and easy to carry out. For accurate diagnosis, it is advisable to combine this method with blood cultures and consult the result with the doctor.
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Establishment of the dependance of detection time in BacT/Alert SA bottles on a size of inoculum.
Jašková, Martina ; Buchta, Vladimír (advisor) ; Lesná, Jiřina (referee)
1 Summary This work deals with the sepsis problems and possibilities of its diagnostics with the help of a quantitative bacteriological investigation using hemocultural systems of BacT/Alert and Bactec. We focused on the yeasts genus Candida and tested the five most frequent species. The first part is dedicated to a theoretical introduction of the whole issue concerning the blood-course and the sepsis. It analyses the pathogeny of these infections and its generators, sepsis clasification and risk factors. It also mentions the diagnostic methods, both clinical and laboratory. Then the following part of the theoretical text is concerned with the hemoculture and automatic hemocultural systems BacT/Alert and Bactec. The practical part shows the used method description as well as the materials and tools. There is also a detailed work process description. The result part contains various graphs and tables of the dependance of the times to detection on the amount of the inoculum yeasts into hemocultural small bottles. The results show that the times to detection become shorter with the increasing amount of inoculum micro-organisms. Both systems deliver equivalent results. The growth curves designed by us could be used in a clinical practice for a quantitative determination of fungemia and a more sophisticated...
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