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Resistance of Escherichia coli to selected antibiotics in the Písek district in 2016
BROMOVÁ, Karolína
The aim of my work was to gather information on resistance of Escherichia coli to selected antibiotics. To show wrong use of antibiotics and to prove that this problem should begin to solve. The research part was performed by data processing, cultivation, sensitivity determination and determination of a phylum using various laboratory methods. In my research, I used Escherichia coli from the urine I used phyla previously designated. To determine the correct phylum of Enterobacteriaceae, I made use of biochemical tests such as the ENTERO test 24 N and ESBL MAST test, for the Escherichia coli phyla, I have used the INDOL test and VPT test. To determinate sensitivity to antibiotics, I used the M.I.C disk diffusion test.
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Antibacterial and antiadhesive properties of carbon nanomaterials
Budil, Jakub ; Lišková, Petra (advisor) ; Zikánová, Blanka (referee)
Increasing interest in industrial and medical applications of carbon nanomaterial leads to the need to examine its interactions with living systems. Nanocrystalline diamond (NCD) films possess high mechanical and chemical stability which, together with its biocompatibility with human cells, enables applications in human body. Some of carbon nanoparticles possess strong antibacterial activity. In this work the effects of NCD with hydrogen, oxygen and fluorine termination deposited on glass and silicone on adhesion of gram-negative bacteria Escherichia coli K-12 in mineral medium is described and the impact of cultivation medium on effects of NCD films is compared. Prior the growth of the E. coli biofilm on NCD films, the method for quantification of biofilm using crystal violet staining and the method for biofilm cultivation in mineral medium were optimised. The properties of NCD film are independent on the base substrate. Hydrogen and fluorine terminated NCD films show antiadhesive properties only in mineral medium but not in complex medium. This is explained by formation of a conditioning film on the surface of the NCD film during cultivation in complex medium. On the other hand, O-NCD film supports bacterial adhesion in both cultivation media. Second part of this thesis is dedicated to carbon...
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Resistances of Escherichia coli to selected antibiotics in a district of Písek for the year 2016
BROMOVÁ, Karolína
Resistance to antibiotics is becoming a global problem. In my work I focused on the resistance of Escherichia coli in the Písek district in 2016. Escherichia coli is the most common cause of urinary tract infections. On average, every second woman and every fifth male will experience urinary tract infection. Resistance problems have met for many years. Previously effective antibiotics are now ineffective. Often they have to go beyond wide-spectrum antibiotics that have a number of side effects (diarrhea, yeast infections), are more expensive and have an impact on the economy. In the Czech Republic, we do not yet have the same level of resistance as in other countries, In Greece. Therefore, we should take an example from other countries and avoid massive use of antibiotics. The objectives of my work were to collect information on Escherichia coli resistance, to compare the differences between adult and pediatric patients and to determine the degree of ESBL strains in the Písek district in 2016. I compare the results of my research with the results of the urinalysis study of NRL SZÚ in Prague for 2016. In the theoretical part, I have dealt mainly with antibiotic characteristics, antibiotic resistance methods and briefly describe Escherichia coli. In its practical part, methods of identifying bacteria (ENTERO test 24N) are described. Principles of biochemical tests (VP test, INDOL test) to help us determine what type of bacteria might be. I also describe the principles and use of sensitivity assays (Disk diffusion test, M.I.C. microdilution test). Using the ESLB MAST test, I discovered the extent to which ESBL beta-lactamase-producing strains with extended spectrum of effect, which cause multi-resistance, were found in the Písek district. Furthermore, the practical part contains evaluation of resistance statistics on selected antibiotics, which I processed from data from the clinical microbiology of Písek Hospital. For my observation of Escherichia coli resistance, I chose 5 types of antibiotics used in the treatment of urinary tract infections - Amoxicillin, amoxicillin + clavulanate, nitrofurantoin, cefotaxim, and gentamicin. The results of my work demonstrate that resistance to selected antibiotics is relatively high. It appears that women have more resistant strains than men, which can be explained by the fact that women are more likely to have urinary infections and more ESBL strains are present. No ESBL strains are present in pediatric patients (0 - 19 years). It also follows that girls are more likely to suffer from urinary infections than boys, with the only exception being girls and boys aged 0-3 years old, according to my research with urinary infections suffer more boys than girls.
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Antivirotické a antibakteriální účinky biologicky aktivních látek z přírodních zdrojů a jejich potenciální využití proti klíšťaty přenášeným patogenům
LUDVÍKOVÁ, Nikola
The first aim of this study was to detect antiviral activities of substances isolated from natural products against tick-borne encephalitis virus in in vitro model. Resveratrol isolated from plant material and adamantane derivatives were studied in this regard. The maximum tolerated concentrations of the investigated substances were determined for the glioblastoma cell line used in the experiments using flow cytometry and subsequently. Next, the number of viral particles produced by infected cells after incubation with the studied substances was determined using plaque titration. Possible antibacterial effects of the studied materials against standard strains of bacteria Staphyloccocus aureus, Staphyloccocus epidermidis, Escherichia coli and selected strains of Borrelia burgdorferi spirochetes were examined.
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Oxidative stress in bacteria - with an emphasis on the model organism of Escherichia coli
Moravcová, Andrea ; Lichá, Irena (advisor) ; Čáp, Michal (referee)
Most bacterial species encounter aerobic conditions during their life, which can be toxic. This leads to a state of oxidative stress. Toxicity of aerobic environment results from the chemical properties of molecular oxygen and its reactive species (ROS). Bacteria had to adapt to these conditions in the past to ensure preservation and prosperity. This thesis is preferably focused on oxidative stress adaptations in the most elaborated bacterial model - Escherichia coli. Regulation of adaptations at the regulation of transcription, translation and metabolism level are described with emphasis on molecular mechanisms. The main adaptation mechanism against oxidative stress is the deactivation of ROS, as well as the repair of damaged cell structures (macromolecules). These enzyme activities are regulated by several transcriptional regulators. The transcriptional regulators OxyR and SoxRS have been well studied in E. coli. Even though these regulators are conserved across the bacterial spectrum, they may not have the same function in all organisms. For this reason, also other, more or less studied bacterial species - Bacillus subtilis, Streptomyces coelicolor, Pseudomonas putida, Pseudomonas aeruginosa - were included in this thesis. The various strategies of how these bacteria use not only OxyR and SoxRS...
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Biological effects of substances isolated from Isoptera species
Dušková, Simona ; Hrstka, Miroslav (referee) ; Brázda, Václav (advisor)
This thesis was focused on monitoring the viability of eukaryotic and prokaryotic cells after exposure of termites-isolated chemicals. Recently, evidence of antibacterial and antifungal properties of these defense substances has grown, and they can find a wide range of uses not only in the pharmaceutical industry. In this work, three defensive substances from termites were studied: nerolidol, nitropentadecene and methylanthranilate. Their antibacterial effects, minimal inhibitory concentrations and minimal bactericidal concentrations against Escherichia coli STBL3 strain were monitored. Further, their cytotoxic effects on eukaryotic non-tumor (HEK293FT) and tumor cells (MCF7) as well as their effect on plasmid DNA were studied. Antibiotic ampicillin and cytostatic cisplatin were used as control substances for antibacterial and cytotoxic effects, respectively. In the case of the action of nerolidol, nitropentadecene and methylanthranilate on the STBL3 strain, antibacterial activity was not demonstrated. Cytotoxic effects were observed nerolidol and nitropentadecene. None of the examined substances modified the plasmid DNA.
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Testování antimikrobiální aktivity obalových materiálů s rostlinnými extrakty proti E. coli a koliformním bakteriím
Šabršula, Jan
This dissertation deals with evaluation and testing of food packiging materials antimicrobial aktivity that contain plant extracts and help in the fight against Eschericia coli and other coliform bacteria. This dissertation is divided into several parts. The first half of the work contains a literature review publishing about packaging materials containing plant extracts. It is also focused on literature review on the coliform bacteria, especially Escherichia coli genus, describes these microorganisms and their metabolic products, the effects of metabolic products which may negatively affect human health. Another part deals with measures to prevent undesirable microorganisms. The second half of the work has been engaged in actual testing of packaging materials containing plant extracts on relevant model organisms or directly on food. Data, acquired by testing are processed, compared with the figures in the available literatures and are listed at the end of work.
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Domain structure and function of primary bacterial sigma factors
Kálalová, Debora ; Krásný, Libor (advisor) ; Roučová, Kristina (referee)
Transcription initiation is one of the crucial steps of gene expression. A multisubunit enzyme RNA polymerase (RNAP) transcribes the genetic information from DNA to RNA. However, RNAP itself is unable to recognize a specific promoter and initiate transcription. For this purpose, bacteria have a protein called σ factor, which binds to RNAP and together form the RNAP holoenzyme. In this thesis I describe the mechanism of bacterial transcription and the structure, function and regulation of σ factors. I focus mainly on the primary σ factors of two important model species, namely gramnegative Escherichia coli and grampositive Bacillus subtilis. I describe them in the context of alternative σ factors, and I point out their differences in structure, function and regulation. Key words: RNA polymerase, primary σ factors, transcription, bacteria, Bacillus subtilis, Escherichia coli
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Study of biofilm formation of bacterial isolates from milk and dairy products
Nováková, Veronika ; Demnerová, Kateřina (advisor) ; Seydlová, Gabriela (referee)
Bacterial biofilm is a complex community of microbial cells, which are embed into the extracellular pollysacharide matrix. Typical ability of the biofilm is the ability to adhere to either abiotic, or biotic surfaces. The formation of biofilm is a dynamic process, which finally formes a 3D multicellular complex. The initial phase is called the adhesion. After that process is done, the extracellular polymeric matrix is produced to create living conditions of bacteria in biofilm. Biofilm has hight level of antimicrobial resistance. This resistance consists of physical and chemical barriers, which effectively block diffusion and penetration of antimicrobial substances inside the biofilm. Biofilms cause problems in food industry, where it could be origin of food contaminations. Thefore it is necessary to understand the relationship between microorganisms and materials used in food industry. Key words: biofilm, milk and dairy products, milk and dairy industry, disifectanc, Escherichia coli, Staphylococcus spp.
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Mechanism of secretion of adenylate cyclase toxin from Bordetella pertussis via Type I secretion system (TISS)
Klímová, Nela ; Bumba, Ladislav (advisor) ; Konopásek, Ivo (referee)
Type I secretion system in Gram-negative bacteria translocates proteins from the cytoplasm to the extracellular medium in a single step across both membranes. The membrane-spanning channel is made up of just three proteins - an ATPase in the inner membrane, a membrane fusion protein and a specific outer membrane protein. This work provides a summary of current knowledge concerning the structure of the secretion system, as well as the assembly of the trans-envelope complex and the mechanism of protein secretion. The role of substrate folding on secretion is highlighted. It deals to some extent with the properties of the substrates translocated by the type I secretion system, with emphasis on the adenylate cyclase toxin of Bordetella pertusis, the agent causing whooping cough.
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