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Influence of environment in host cells on heterogeneity of virulence factors expression in Salmonella
Mathéová, Paulína ; Černý, Ondřej (advisor) ; Konopásek, Ivo (referee)
Bacteria of the genus Salmonella are one of the most important human pathogens. Salmonella expresses several virulence factors, including the type three secretion system encoded on the Salmonella pathogenicity island 2 (SPI-2 T3SS) and its effector proteins. SPI- 2 T3SS effector proteins allow the bacteria to colonize host cells, persist there and use them as a Trojan horse for migration throughout the host organism. Although the function of the SPI- 2 T3SS is essential for the bacterial population during systemic infection, some bacteria do not express this virulence factor and benefit from its expression by other members of the population. Similar heterogeneity in expression of other virulence factors has been shown to be crucial for their function. This work focuses on the heterogeneity of expression of selected SPI-2 T3SS effector proteins under the influence of host factors (pH, ROS, RNS) affecting bacteria during intracellular infection of macrophages. Using a fluorescent reporter system suitable for flow cytometry the expression of selected effector proteins was detected at the level of individual bacteria. The obtained data show, that individual bacteria respond differently to the decrease in pH in their vicinity. Part of the bacterial population starts to express the studied effector...
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Diarrheal diseases caused by Salmonella sp. and Campylobacter sp.
Adamcová, Anežka ; Vejsová, Marcela (advisor) ; Voxová, Barbora (referee)
Anežka Adamcová Diarrheal diseases caused by Salmonella sp. and Campylobacter sp. Bachelor thesis Charles University in Prague, Faculty of pharmacy in Hradec Králové Laboratory technician This bachelor thesis deals with diarrheal disease caused by Campylobacter sp. and Salmonella sp. The thesis is divided to four sections. The first section is about diarrhoea and its characteristics and causes. In the second section the characteristics of Campylobacter sp. is described and the major part of this section describes campylobacter enteritis or campylobacteriosis. Campylobacter jejuni is the most common agent. The third section deals with Salmonella sp. It again describes characteristics of this genus and focuses on salmonellosis enteritis or salmonellosis. Salmonella Enteritidis is the most common agent. Both genera are gram-negative bacteria and they affect intestinal tract. They cause bacterial enteritis, which is often connected with diarrhoea. Incidence of campylobacteriosis exceeded the incidence of salmonellosis for the first time in 2007. Infections have similar course. Besides diarrhoea, fever and stomach ache can also occur. Pain is similar as in case of appendicitis. Laboratory test is needed to differentiate between the two. In the last section I analyzed data obtained from the Centre for...
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Heterogeneity of expression of virulence factors of Salmonella.
Mathéová, Paulína ; Černý, Ondřej (advisor) ; Lichá, Irena (referee)
The emergence of phenotypically heterogeneous individuals within an isogenic bacterial population is considered to be an important adaptation to the host environment. It allows survival of some bacterial subpopulations under diverse stress conditions caused by the host immune system, the emergence of a "division of labor" and cooperation between individual bacteria. Bacteria of the genus Salmonella are important pathogens in humans and livestock. Many of the key virulence factors of Salmonella are heterogeneously expressed. The phenotypic diversity of individual bacteria allows certain individuals to escape the host's immune system and ensure that the gene pool is preserved to future generations. In case when change in conditions causes complete extinction of part of the Salmonella population from the environment, the remaining individuals are able to restore the size of the population and phenotypic diversity, after overcoming unfavourable conditions. This work summarises the knowledge about heterogeneity of expression of virulence factors of Salmonella and the characteristics of individual subpopulations in different environmental conditions. Keywords: Salmonella, heterogeneity, virulence factors, bet-hedging, division-of-labor, bacterial subpopulations.
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Mikrobiologie koření - stanovení a porovnání výskytu významných skupin mikroorganismů ve vzorcích koření - pepře černého celého a pepře černého mletého
Procházková, Marcela
The dissertation is occupy with microbial settlement of black pepper, which is one of the world's most widely used spices. Characterizes each kind of pepper, discribe microorganisms occurring in spices and spice treatments. It also state legislative limits of microorganism occurrence. The practical part of this work deals with experimental determination of selected groups of microorganisms in black pepper. Analyzed samples of black pepper were purchased in business chains, sold under a known brand and private label and also in shops dealing only with spices and herbs. The results of the work shows that microbial contamination of spices is constantly decreasing and in most cases doesn’t exceed the allowed limits. The most contaminated sample belonged to private label samples, and the least contaminated sample belonged to wholesale spice distributors.
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Diarrheal diseases caused by Salmonella sp. and Campylobacter sp.
Adamcová, Anežka ; Vejsová, Marcela (advisor) ; Voxová, Barbora (referee)
Anežka Adamcová Diarrheal diseases caused by Salmonella sp. and Campylobacter sp. Bachelor thesis Charles University in Prague, Faculty of pharmacy in Hradec Králové Laboratory technician This bachelor thesis deals with diarrheal disease caused by Campylobacter sp. and Salmonella sp. The thesis is divided to four sections. The first section is about diarrhoea and its characteristics and causes. In the second section the characteristics of Campylobacter sp. is described and the major part of this section describes campylobacter enteritis or campylobacteriosis. Campylobacter jejuni is the most common agent. The third section deals with Salmonella sp. It again describes characteristics of this genus and focuses on salmonellosis enteritis or salmonellosis. Salmonella Enteritidis is the most common agent. Both genera are gram-negative bacteria and they affect intestinal tract. They cause bacterial enteritis, which is often connected with diarrhoea. Incidence of campylobacteriosis exceeded the incidence of salmonellosis for the first time in 2007. Infections have similar course. Besides diarrhoea, fever and stomach ache can also occur. Pain is similar as in case of appendicitis. Laboratory test is needed to differentiate between the two. In the last section I analyzed data obtained from the Centre for...
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Salmonella infection in poultry and the national eradication programme
NOVOTNÁ, Marie
The topic of the thesis is the incidence of salmonella infections in poultry and National Recovery Programs that were established in the Czech Republic on the 1stofJanuary 2007 under the European legislation, specifically by Regulation (EC) No 2160/2003 of the European Parliament and of the Council from the 17th of November 2003 about the reduction of Salmonella bacteria and other agents of zoonosis in the food chain. Currently five recovery programs oriented on the reduction of Salmonella are taking place in the Czech Republic. The basis of the programs is monitoring of Salmonella incidence in breeding via taking of samples. These programs were established in order to reduce the amount of cases of human Salmonella deseases because the poultry products are the most common source of the human infections. The programs could be considered effective. For this effectiveness is important to respect the principles of correct hygiene practices.
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