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Significance, occurrence and determinants of horizontally transmissible colistin resistance in Gram negative bacteria
Kislíková, Karolína ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
Colistin, also known as polymyxin E, is antibiotics active against most of Gram-negative bacteria. In the pas decade, emergency of multidrug-resistant bacteria led to increase of colistin administration as a last resort antibiotic for human infections. The first plasmid-mediated colistin resistance gene mcr-1 was identified in 2015 in animals in China and after first detection, additional mcr genes: mcr-2, mcr-3, mcr-4, mcr-5, mcr-6, mcr-7 a mcr-8 were described throughout the world. The aim of this thesis was to clarify whether there is horizontal transmission colistin resistance encoded by the mcr genes in gram-negative bacteria isolated from the environment, animals and their breeding and food. The mcr-1 gene was detected in 2 strains Escherichia coli isolated from waste water. The mcr-4 gene was detected in 1 strain Shewanella putrefaciens isolate obtained from the lake. The environment is the most important source and way of spreading this type of resistance in the Czech Republic.
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Structure and evolution of efflux pump in gramnegative bacteria.
Gálová, Diana ; Lichá, Irena (advisor) ; Matyska Lišková, Petra (referee)
Drug resistence in microorganisms is of major concern and there is an increasing number of pathogenic bacteria resistent to clinically used antibiotics. The major mechanism of resistence in Gram-negative is active efflux that prevent the intracellular accumulation of antibiotics to toxic levels. We recognise five families of efflux pumps, mainly using proton motive force to translocate the substrate, less common driven by ATP hydrolysis. The multidrug pumps with broad substrate specifity are of a key role in drug resistance of pathogens, typically represented by RND superfamily. The source of efflux pumps are probably the producers of antibiotics and organisms exposed to toxic compounds in their natural habitat. The genes for resistance can then spread out via horizontal gene transfer to other bacteria. It is presumed that eflux pumps have developed from transporters serving physiological functions like transport of endogenous substrates.
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Significance, occurrence and determinants of horizontally transmissible colistin resistance in Gram negative bacteria
Kislíková, Karolína ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
Colistin, also known as polymyxin E, is antibiotics active against most of Gram-negative bacteria. In the pas decade, emergency of multidrug-resistant bacteria led to increase of colistin administration as a last resort antibiotic for human infections. The first plasmid-mediated colistin resistance gene mcr-1 was identified in 2015 in animals in China and after first detection, additional mcr genes: mcr-2, mcr-3, mcr-4, mcr-5, mcr-6, mcr-7 a mcr-8 were described throughout the world. The aim of this thesis was to clarify whether there is horizontal transmission colistin resistance encoded by the mcr genes in gram-negative bacteria isolated from the environment, animals and their breeding and food. The mcr-1 gene was detected in 2 strains Escherichia coli isolated from waste water. The mcr-4 gene was detected in 1 strain Shewanella putrefaciens isolate obtained from the lake. The environment is the most important source and way of spreading this type of resistance in the Czech Republic.
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Type II secretion system in gram negative bacteria.
Klápšťová, Veronika ; Doležal, Pavel (advisor) ; Mach, Jan (referee)
This thesis describes the structure and the assembly of the type II secretion system which is found in some gram negative bacteria such as Vibrio cholerae, Pseudomonas aeruginosa, Legionella pneumophila or Klebsiella oxytoca and which transports their exoproteins across the outer membrane. The thesis also presents some important substrates translocated by this system - toxins, enzymes and proteins involved in bacterial metabolism or motility - and hypothetical mechanism of the secretion. Conclusion is focused on the discovery of the secretion system in mitochondria of some protists and its importance for the research of the evolution of eukaryotic organisms.
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Structure and evolution of efflux pump in gramnegative bacteria.
Gálová, Diana ; Lichá, Irena (advisor) ; Matyska Lišková, Petra (referee)
Drug resistence in microorganisms is of major concern and there is an increasing number of pathogenic bacteria resistent to clinically used antibiotics. The major mechanism of resistence in Gram-negative is active efflux that prevent the intracellular accumulation of antibiotics to toxic levels. We recognise five families of efflux pumps, mainly using proton motive force to translocate the substrate, less common driven by ATP hydrolysis. The multidrug pumps with broad substrate specifity are of a key role in drug resistance of pathogens, typically represented by RND superfamily. The source of efflux pumps are probably the producers of antibiotics and organisms exposed to toxic compounds in their natural habitat. The genes for resistance can then spread out via horizontal gene transfer to other bacteria. It is presumed that eflux pumps have developed from transporters serving physiological functions like transport of endogenous substrates.
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