|
|
Interaction of the human pathogen Bordetella pertussis with blood serum
Štipl, Daniel ; Večerek, Branislav (advisor) ; Kamanová, Jana (referee)
Bordetella pertussis is a Gram-negative strictly human pathogen and the major causative agent of whooping cough or pertussis. The incidence of this highly contagious respiratory disease in developed countries has increased in the last decades. One of the less characterized virulence factors of B. pertussis is the type three secretion system (TTSS) which is responsible for the secretion of the effector proteins into host eukaryotic cells. This diploma thesis sheds light onto factors influencing TTSS in vitro activity. Although TTSS of laboratory strain Tohama I was induced by biologically active compounds present in blood (e. g. complement proteins), TTSS of recent clinical isolate B1917 seems to be induced permanently. Furthermore, BB0302 encoding a GntR family transcription regulator in B. bronchiseptica RB50 (homologous to BP0209 of Tohama I) was studied, however, the deletion of this gene did not affect the TTSS functionality. Serum resistance is a factor that plays a key role in the pathogenesis of B pertussis. We show that Czech recent isolates (2008-2015) are significantly more resistant to serum killing in vitro than the original vaccine strains (1954-1965). This phenomenon seems to result from the adaptation of global B. pertussis population to its human host. In addition, this diploma...
|
|
|
Virulence factors of Bordetella pertussis
Držmíšek, Jakub ; Večerek, Branislav (advisor) ; Vopálenská, Irena (referee)
Bordetella pertusis is a Gram-negative, aerobic, non-spore-forming coccobacillus. Although it's strictly human pathogen, it's possible to infect other mammals at laboratory conditions. Transmission among hosts is mediated via respiratory tract droplets. Infection could be direct, host to host, alternatively by contaminated environment. Bordetella colonizes upper respiratory tract, wherefrom descends into lungs and causes disease known as whooping cough or pertussis leading to 195 000 deaths of 16 mil. incidences per year (according to WHO report from 2010). More than twenty years before, respectively to found pertussis toxin, that time intensively under examination, pertussis was marked as toxin-mediated disease. In the course of time, more other virulence factors were revealed, that could be divided into groups of adhesins, toxins and others. Adhesins are filamentous haemagglutinin, pertactin and fimbriae. Toxins include pertussis toxin, adenylate cyclase, tracheal cytotoxin, dermonecrotic toxin and lipopolysaccharide. Most of virulence factors are regulated by two component system Bvg. However, it is needed lots of other factors for successful infection as for example autotransporters or so called siderophores serving as iron acquisition from environment. Secretion of virulence factors is mediated by its...
|
|
|
Interaction of the human pathogen Bordetella pertussis with blood serum
Štipl, Daniel ; Večerek, Branislav (advisor) ; Kamanová, Jana (referee)
Bordetella pertussis is a Gram-negative strictly human pathogen and the major causative agent of whooping cough or pertussis. The incidence of this highly contagious respiratory disease in developed countries has increased in the last decades. One of the less characterized virulence factors of B. pertussis is the type three secretion system (TTSS) which is responsible for the secretion of the effector proteins into host eukaryotic cells. This diploma thesis sheds light onto factors influencing TTSS in vitro activity. Although TTSS of laboratory strain Tohama I was induced by biologically active compounds present in blood (e. g. complement proteins), TTSS of recent clinical isolate B1917 seems to be induced permanently. Furthermore, BB0302 encoding a GntR family transcription regulator in B. bronchiseptica RB50 (homologous to BP0209 of Tohama I) was studied, however, the deletion of this gene did not affect the TTSS functionality. Serum resistance is a factor that plays a key role in the pathogenesis of B pertussis. We show that Czech recent isolates (2008-2015) are significantly more resistant to serum killing in vitro than the original vaccine strains (1954-1965). This phenomenon seems to result from the adaptation of global B. pertussis population to its human host. In addition, this diploma...
|
|
|
The structure and role of type III secretion system and other virulence factors in pathogenesis of pertussis
Štipl, Daniel ; Večerek, Branislav (advisor) ; Pinkas, Dominik (referee)
Bordetella pertussis is a significant human pathogen which colonises a respiratory tract. The infection with B. pertussis results in serious and highly contagious disease called pertussis or whooping cough. B. pertussis produces wide range of virulence factors such as pertussis toxin, adenylate cyclase toxin, dermonecrotic toxin, tracheal cytotoxin, adhesins and type III secretion system (T3SS). The BvgAS is two-component signal transduction system that provides the complex regulation of B. pertussis virulence. The virulence factor T3SS is used by some Gram-negative bacteria to colonise the host and is responsible for pathogenesis of the infection. T3SS takes a role in virulence of mammalian pathogen B. bronchiseptica, closely related to B. pertussis. The importance of T3SS in virulence of B. pertussis remains to be investigated. Significant advance in structure, function and regulation of the most of virulence factors have been accomplished in last few decades. The causative agents of pathogenesis in that infection remain unknown. Key words: Bordetella, T3SS, gene expresssion regulation, virulence factor, pathogenesis
|
|
|
Finalizing the full genome sequence of epidemic strain Burkholderia cenocepacia ST32 and identification of a prognostic marker for infections that are caused by the ST32 strain in patients with cystic fibrosis
Vavrová, Jolana ; Dřevínek, Pavel (advisor) ; Wiedermannová, Jana (referee)
Burkholderia cenocepcia is one of the serious infectious agents of respiratory tract among cystic fibrosis patients. There are problems mainly with strains which are capable of epidemic spread. The known epidemic in the Czech Republic was caused by ST32 strain in the past. In this work, there was completed whole genome sequence of referential isolate 1232 of B. cenocepacia ST32 in cooperation with bioinformatics by new generation sequencing techniques and by determining the problematic areas by a combination of Sanger sequencing bioinformatics approaches and manual assembling of sequence reads localized in these areas. The final version of the genome sequence was annotated by PGAAP and at the present time it is finalized. Second part of this work is dedicated to looking for a prognostic marker of infection caused by ST32 strain in patients with cystic fibrosis. We analysed the results of ST32 trancriptomic experiment and chose genes possibly connected with the cepacia syndrome - serious, mostly fatal state of infection. By quantitative PCR we compared their expression in isolates from 4 patients from time of cepacia syndrome and month before that. We checked the possibility of direct detection of the expression of these genes in clinical material. We identified genes for type III secretion system as...
|
|
|
Virulence factors of Bordetella pertussis
Držmíšek, Jakub ; Večerek, Branislav (advisor) ; Vopálenská, Irena (referee)
Bordetella pertusis is a Gram-negative, aerobic, non-spore-forming coccobacillus. Although it's strictly human pathogen, it's possible to infect other mammals at laboratory conditions. Transmission among hosts is mediated via respiratory tract droplets. Infection could be direct, host to host, alternatively by contaminated environment. Bordetella colonizes upper respiratory tract, wherefrom descends into lungs and causes disease known as whooping cough or pertussis leading to 195 000 deaths of 16 mil. incidences per year (according to WHO report from 2010). More than twenty years before, respectively to found pertussis toxin, that time intensively under examination, pertussis was marked as toxin-mediated disease. In the course of time, more other virulence factors were revealed, that could be divided into groups of adhesins, toxins and others. Adhesins are filamentous haemagglutinin, pertactin and fimbriae. Toxins include pertussis toxin, adenylate cyclase, tracheal cytotoxin, dermonecrotic toxin and lipopolysaccharide. Most of virulence factors are regulated by two component system Bvg. However, it is needed lots of other factors for successful infection as for example autotransporters or so called siderophores serving as iron acquisition from environment. Secretion of virulence factors is mediated by its...
|
guest ::
