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Assessment of drugs in settlings with waste water treatment
Hájek, Radek ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
This bachelor thesis is focused on asessment of pharmaceuticals in wastewater treatment plant sludge. Two macrolide antibiotics (erythromycin and clarithromycin) and three non-steroidal anti-inflammatory drugs (ibuprofen, naproxen and diclofenac) were assessed. Sample of sludge was taken in municipal wastewater treatment plant in Brno-Modřice. Analytes were obtained using pressurized solvent extraction (PSE) or ultrasonic solvent extraction (USE). Clean-up was performed by solid phase extraction (SPE). Ultra high performance liquid chromatography followed by UV-VIS diode array detection was used for quantitative determination of the analytes.
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Cellular factors influencing the antibiotic resistance by ABC-F proteins
Kýr, Jan ; Balíková Novotná, Gabriela (advisor) ; Dolejšová, Tereza (referee)
Antibiotic resistance is one of the main problems modern medicine has to face. In order to control it, it is important first to understand the mechanisms by which resistant pathogens bypass antibiotic treatment. One of the important protein families conferring resistance to 50S binding antibiotics is the ARE ABC-F protein family. A member of this protein family is the MsrA protein, which confers resistance to 14- and 15-membered macrolides. Loss-of-function mutations in the non-essential chaperone ClpX were found to a significant ly enhance the action of the MsrA protein. This leads to the significant increase in the resistance conferred by this protein. The exact mechanism by which ClpX affects MsrA function is still unknown. In this the diploma thesis was demonstrated that chaperone protein ClpX affects the resistance to erythromycin conferred by MsrA protein, due to the interaction with an unknown essential protein, which is mediated by a functional N-terminal zinc-binding domain of the chaperone. Furthermore, it was demonstrated in this work that loss of GluTR function influence the MsrA ability to confer resistance. The results of this work will bet he basis for further reasearch, which will lead to a more detailed understanding of the mechanism of resistance conferred by these proteins and...
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Critical sites determining the resistance phenotype of ABC proteins from the ARE subfamily and the molecular mechanism of their function
Lenart, Jakub
Vga(A) and Msr(A) are resistance proteins belonging to the ARE subfamily of ABC -F proteins. They confer resistance to inhibitors of the peptidyltransferase center. It has been proposed that the mechanism of resistance is based on interaction with a transmembrane partner that forms the functional transporter. Their ribosomal function has been described by cryoelectron microscopy of ribosome complexes with ABCF mutants unable to hydrolyze ATP. However, the exact mechanism of resistance is not yet known. We have produced the mutant proteins combining the four amino acid residues in Vga(A) and Vga(A)LC at the linker tip, and we were the first to describe the effects of substrate specificity of the single mutants. Amino acid positions 212 and 220 are important for resistance to lincosamides and pleuromutilins, respectively, while position 219 is responsible for resistance to streptogramin A. Each amino acid property plays a critical role in conferring antibiotic specificity, as confirmed by the fact that amino acid substitution at position K218T in the Vga(A) protein causes the shift in resistance from streptogramins to lincosamides and pleuromutilins. The mechanism of resistance conferred by Vga(A) is ribosomal protection. This is supported by the fact that the rate of [3H]-lincomycin accumulation in...
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Antibiotic resistance conferred by members of ARE subfamily of ABC proteins
Veselá, Ludmila ; Balíková Novotná, Gabriela (advisor) ; Borčin, Kateřina (referee)
The main topic of this thesis is the ARE subfamily of ABC transporters. The importance of the proteins of this subfamily lies in the fact that they confer resistance to several classes of clinically important antibiotics: macrolides, lincosamides, streptogramines and pleuromutilines and they do it in significant pathogens, as for example Staphylococcus aureus. Compared to canonical ABC transporters, the structure of ABC proteins lacks the transmembrane domain (TMD) and so far, there where not even found an integrating transmembrane protein. Due to these facts, the mechanism of resistance conferred by these proteins remains unclear. In the thesis, both suggested hypotheses of the mechanism of how these proteins work are discussed. The first hypothesis presumes the active efflux of antibiotics out of the bacteria. The second hypothesis suggests release of antibiotic from its binding site initiated by ARE proteins, followed by its passive diffusion out of the cell. Keywords: ABC proteins, ARE proteins, resistance, MLS, Vga
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Immunomodulatory effects of macrolide antibiotics
Zemánková, Jana ; Stříž, Ilja (advisor) ; Krulová, Magdaléna (referee)
Macrolide antibiotics are well known not only for their antibacterial properties, but also for their recently discovered anti-inflammatory properties. They are able to significantly suppress destructive and in many cases life-threatening inflammation, an effect which is desired especially in chronic inflammatory diseases. The principle which their act is the modulation of the various components of the immune system. These effects are called "immunomodulatory" and can also include the effect on epithelial cells and their secretory activity, as well as the effect on pathogens which can colonize the airways and contibute to pathogenesis and the emergence of the chronic inflammatory respiratory diseases. This thesis summarizes the most important known mechanisms, by which macrolide antibiotics exert these immunomodulatory effects, and also notes examples of diseases whose treatment is the most clinically significant. Macrolide antibiotics posessing these uniqe anti-inflammatory properties are well tolerated and severe side-effects are rare. However, the most serious risk is the emergence of resistance and that is the main reason why this treatment can not be recommended without reservation. It is up to each doctor to consider the risks and benefits of the treatment in each individual patient.
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Critical sites determining the resistance phenotype of ABC proteins from the ARE subfamily and the molecular mechanism of their function
Lenart, Jakub ; Balíková Novotná, Gabriela (advisor) ; Melter, Oto (referee) ; Branny, Pavel (referee)
Vga(A) and Msr(A) are resistance proteins belonging to the ARE subfamily of ABC -F proteins. They confer resistance to inhibitors of the peptidyltransferase center. It has been proposed that the mechanism of resistance is based on interaction with a transmembrane partner that forms the functional transporter. Their ribosomal function has been described by cryoelectron microscopy of ribosome complexes with ABCF mutants unable to hydrolyze ATP. However, the exact mechanism of resistance is not yet known. We have produced the mutant proteins combining the four amino acid residues in Vga(A) and Vga(A)LC at the linker tip, and we were the first to describe the effects of substrate specificity of the single mutants. Amino acid positions 212 and 220 are important for resistance to lincosamides and pleuromutilins, respectively, while position 219 is responsible for resistance to streptogramin A. Each amino acid property plays a critical role in conferring antibiotic specificity, as confirmed by the fact that amino acid substitution at position K218T in the Vga(A) protein causes the shift in resistance from streptogramins to lincosamides and pleuromutilins. The mechanism of resistance conferred by Vga(A) is ribosomal protection. This is supported by the fact that the rate of [3H]-lincomycin accumulation in...
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Molecular analysis of resistance gene vga(A)LC identification of key aminoacid residues.
Kroová, Michaela ; Najmanová, Lucie (advisor) ; Vopálenský, Václav (referee)
Protein Vga(A) gives staphylococci resistance to streptogramins A. The recently discovered protein Vga(A)LC differs from Vga(A) only by 7 amino acid residues, but this difference is sufficient for shift of its substrate specificity towards lincosamides. The group of four amino acids in the central part of protein (LGAG in Vga(A) and SVTS in Vga(A)LC) was detected to be crucial for the substrate specificity. In this diploma thesis 5 alternativesets of vga(A)LC gene point mutations were prepared in order to determine the impact of individual amino acids of the aforementioned group on the resistance phenotype. Mutations were prepared in vector pGEM® -T and cloned into shuttle vector pRB374. The prepared constructs were transformed by electroporation into the sensitive strain of Staphylococcus aureus RN4220 and values of minimum inhibitory concentration (MIC) were measured for lincomycin, clindamycin and pristinamycin IIA by the agar dilution method. The transformation was not successful in one of the mutations. Results of setting MIC for the remaining four mutations do not make it possible to specify uniquely the ratio of individual amino acids for determining substrate specificity. Two of the amino acids were found to be important. We anticipate preparation of more mutations.
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Antibiotic resistance conferred by members of ARE subfamily of ABC proteins
Veselá, Ludmila ; Balíková Novotná, Gabriela (advisor) ; Borčin, Kateřina (referee)
The main topic of this thesis is the ARE subfamily of ABC transporters. The importance of the proteins of this subfamily lies in the fact that they confer resistance to several classes of clinically important antibiotics: macrolides, lincosamides, streptogramines and pleuromutilines and they do it in significant pathogens, as for example Staphylococcus aureus. Compared to canonical ABC transporters, the structure of ABC proteins lacks the transmembrane domain (TMD) and so far, there where not even found an integrating transmembrane protein. Due to these facts, the mechanism of resistance conferred by these proteins remains unclear. In the thesis, both suggested hypotheses of the mechanism of how these proteins work are discussed. The first hypothesis presumes the active efflux of antibiotics out of the bacteria. The second hypothesis suggests release of antibiotic from its binding site initiated by ARE proteins, followed by its passive diffusion out of the cell. Keywords: ABC proteins, ARE proteins, resistance, MLS, Vga
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Immunomodulatory effects of macrolide antibiotics
Zemánková, Jana ; Stříž, Ilja (advisor) ; Krulová, Magdaléna (referee)
Macrolide antibiotics are well known not only for their antibacterial properties, but also for their recently discovered anti-inflammatory properties. They are able to significantly suppress destructive and in many cases life-threatening inflammation, an effect which is desired especially in chronic inflammatory diseases. The principle which their act is the modulation of the various components of the immune system. These effects are called "immunomodulatory" and can also include the effect on epithelial cells and their secretory activity, as well as the effect on pathogens which can colonize the airways and contibute to pathogenesis and the emergence of the chronic inflammatory respiratory diseases. This thesis summarizes the most important known mechanisms, by which macrolide antibiotics exert these immunomodulatory effects, and also notes examples of diseases whose treatment is the most clinically significant. Macrolide antibiotics posessing these uniqe anti-inflammatory properties are well tolerated and severe side-effects are rare. However, the most serious risk is the emergence of resistance and that is the main reason why this treatment can not be recommended without reservation. It is up to each doctor to consider the risks and benefits of the treatment in each individual patient.
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