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Influence of expression of lmr(C) on the biosynthesis of lincomycin in Streptomyces lincolnensis: Resistance or production?
Veselá, Ludmila ; Balíková Novotná, Gabriela (advisor) ; Beranová, Jana (referee)
The genus Streptomyces produces more than a half of the known bioactive substances, ranking it among the most important bacterial taxons. Streptomyces lincolnensis ATCC 25466 encodes a biosynthetic gene cluster for lincomycin biosynthesis in its genome. Apart from the biosynthetic and regulatory genes, the cluster also contains three resistance genes, lmr(A), lmr(B) a lmr(C), which could protect of the host from the toxicity of a synthesized antibiotic. The Lmr(C) protein belongs to ARE proteins which generaly confer resistance to clinically important classes of antibiotics: macrolides, streptogramins, lincosamides and pleuromutilins. In addition to antibiotic producers, ARE proteins are also present in pathogenic microorganisms. However, the resistance mechanism conferred by these protins which belong to ABC transporters, even though they lack the transmembrane domain, have not been characterized yet. This makes the ARE proteins an interesting subject of the research. Using deletion mutants in resistance genes lmr(A), lmr(B) a lmr(C) we studied their effect on the lincomycin production and resistance to lincosamides, lincomycin and clindamycin with special focus on the function of the lmr(C). We have found that deletion of lmr(C) does not significantly influence lincomycin production and...
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Competition of cells within the population of yeast colony
Očková, Veronika ; Váchová, Libuše (advisor) ; Gášková, Dana (referee)
Competition is a very important natural phenomenon, which causes the rivalry of organisms, in cases such as space limitation or lack of nutrients. It occurs mainly in situations where organisms, including microorganisms live in large populations. Multicellular yeast colonies represent an example of such a population. After the population of yeast cells spends nutrients from the environment, the cells in colonies are able to respond to these changes by production of ammonia functioning as a signaling molecule. Subsequently, the cells are able to change their morphology and metabolism and, dependently on their location within the colony, to create a subpopulation of cells with specific characteristics and functions. It is likely that in the case of mixed colonies formed by the two different strains, a competition between the cells of these two strains could exist. Such rivalry can result in changes in the ratio of cells of the two strains within the colony population, so that the cells of one strain outweigh the other. In this diploma thesis, I compared the growth and development of giant colonies and competition between the cells of selected pairs of strains forming mixed colonies. I focused on the parental strain Saccharomyces cerevisiae BY and its variants labeled with fluorescent proteins. For...
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Antibiotic resistance of Pseudomonas sp.
Gold, Lukáš ; Vejsová, Marcela (advisor) ; Voxová, Barbora (referee)
Lukáš Gold The resistance of Pseudomonas bacteria species to antibiotics Bachelor thesis Charles University in Prague, Faculty of Pharmacy in Hradec Kralove Medical laboratory technician This work was focused on summarising the basic knowledge on the resistance of Pseudomonas bacteria species to antibiotics, and the connection between their resistance and their diagnostics using new techniques, especially the mass spectrometry MALDI - TOF. As an introduction to this very extensive topic, we included a chapter on the general characteristics of Pseudomonas, in order to clarify the mechanisms by which resistance to antibiotics arise. Part of this review also includes laboratory diagnosis using conventional phenotypic methods as well as new techniques, mainly using the mass spectrometry MALDI - TOF. A small and yet considerably significant section of the work includes chapters on the infections caused by the Pseudomonas species and their recommended therapies. The position of the Pseudomonas species as one of the nosocomial pathogens is generally made mention of in this work. This review therefore, contains general information on Pseudomonas species that are related to their resistance to antibiotics, and mainly pertaining to their mechanisms of resistance and production of carbapenemases, which can be...
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The detection of factors virulence and resistance genes bacterial pathogens in patients with cystic fibrosis
Jandová, Oldřiška ; Melter, Oto (advisor) ; Nyč, Otakar (referee)
Cystic fibrosis is an autosomal recessive genetic disorder, which is caused by mutation in CFTR gene (Cystic Fibrosis Transmembrane Conductance Regulator). This gene encodes protein with the same name, which is responsible for pathogenesis of CF. Cystic fibrosis is characteristic for frequent infection of respiratory system, which causes, destruction of lung tissue. These infections are characterized by occurrence of typical bacterial pathogenes, for example: S. aureus, P. aeruginosa etc. S. aureus is one of the most typical opportunistic pathogens, which causes serious difficulties in patients with the cystic fibrosis. Strains of S. aureus are characterized by production of multiple virulence factors and resistance to broad spectrum of antibiotics. Besides common mechanisms of resistance there is also possibility of emergence of so called Small Colony Variants in chronically infected patients. These resistant subpopulation is relatively common among S. aureus isolates of patients with CF. The aim of this work was to study isolates from three patients with cystic fibrosis, who are chronically infected by S. aureus. Our goal was to determine changes in the pattern of the antibiotic resistance and occurrence of virulence factors together with description of SCV strains. Powered by TCPDF (www.tcpdf.org)
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The effect of vanZTei and vanZg expression on resistance to glycopeptide antibiotics in Staphylococcus aureus
Zieglerová, Leona ; Balíková Novotná, Gabriela (advisor) ; Lichá, Irena (referee)
A membrane protein VanZTei which is encoded by the gene vanZ from the vanA glycopeptide resistance gene cluster is a part of the large family of VanZ proteins. VanZTei confers resistance to teicoplanin in Enterococcus faecalis without the presence of other proteins encoded by the cluster. The aim of my work was to compare the ability of two orthologous proteins VanZTei and VanZg (from the genome of Enterococcus faecium) to confer resistance to glycopeptides in Staphylococcus aureus RN4220 and Enterococcus faecium. We have shown that VanZg increases resistance to teicoplanin (Tei) 8 to 16 times the and also to dalbavancin (Dalb) 8 times. VanZTei also confers resistance to Tei and Dalb, but the increase is only twofold. Conversely VanZTei confers resistance to newly synthetized glycopeptides more effectively than VanZg (fourfold increase of resistance confered by VanZTei and two to fourfold increase of resistance confered by VanZg). It suggests that both proteins have different specificity to antibiotics. In despite the mutants of S. aureus RN4220 VanZTei pRMC2 with increased resistance to teicoplanin (MICTei> 8 µg/ml) in which the resistance is dependent on vanZTei expression were selected. These resistant mutants do not carry mutation in a gene vanZTei or in its ribosomal binding site. Neither of the...
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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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Surveillance of bacterial strains producing broad-spectrum beta-lactamase.
VLASOVÁ, Martina
In the first part of my thesis I focus on mapping problems associated with antibiotic therapy and subsequent development of antibiotic resistance. Tracking resistance is based primarily on data collection and evaluation of the results set sensitivity from around the world. Antibiotic resistance is a natural phenomenon that can be observed in the evolution of microbes as one of the mechanisms of adaptation to new conditions in the environment. For this work I have chosen the following research questions. Do the incidence of ESBL strains in the České Budějovice Hospital a.s. increase over time? Are these values comparable to those achieved in another region, namely in Moravian hospitals the University Hospital of Olomouc, Ostrava University Hospital and Regional University Hospital of T. Bata in Zlin? The data collection I made in collaboration with the laboratory technicians and doctors at Hospital?s Bacteriology Laboratory in České Budějovice. Bacteries tested for the detection of ESBL production originated from biological materials, witch came from patients of hospital in České Budějovice. The first objective was to compare the results achieved in the České Budějovice Hospital in the period of 2007 to 2012. If we look at the total number of ESBL strains that have been isolated since 2007, values have upward trend. While in 2007 there were only 64 strains a year later, the number more than doubled. In 2010, the value soared to 281 tribes and in the year 2012, the number was 321 tribes. The incidence of ESBL strains in 2007 increased about five times. In the long term we can say the numbers have increasing tendency and the range of each species in the production of ESBL has significantly changed. In 2007, it was K. pneumoniae strains that dominated the statistics, but over time the strains of E. coli came forefront. Values of 2012 suggest that the presence of ESBL strains of K. pneumoniae is again almost equal to the number of E. coli strains. The second objective was to compare the results of the 2012 with study of the Prevalence of ESBL-positive Enterobacteriaceae in large Moravian hospitals. In the general overview of ESBL producers values in Hospital České Budějovice (5.23%) are comparable to those in Ostrava (4.9%) and in Zlín (4.3%). Number of strains in the Hospital in Olomouc (11.8%) is about twice as high as the numbers in České Budějovice. In this comparison the České Budějovice Hospital is one of the hospitals with a lower incidence of ESBL producers. The České Budějovice Hospital is below the national average, which originate from an elaborate system of care for patients with colonization or infection with ESBL strains, and from therapy control system using antibiotic center. These results may serve to the Hospital in České Budějovice for statistical purposes, and also for proposals for improving patient care. In the discussion, I pointed out the danger of the spread of resistant strains of bacteria in the community and also the associated risks that mentioned bacteria mean for patients injured in mass accidents or disasters. In these cases, number of infections including ESBL producers can penetrate through open wounds into the affected body. Unlike conventional sensitive bacteria those strains are resistant to commonly used antibiotics and thereby endanger the lives of people affected by the accident.
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Diagnosis and therapy of Helicobacter pylori infection
POSPÍŠILOVÁ, Michaela
H pylori is a Gram-negative, microaerophilic rod-shaped moving bacterium, notorious for its urease production. It colonizes gastric mucosa and always leads to chronic gastritis, which may result in the development of other serious diseases, such as gastroduodenal ulcer disease and gastric adenocarcinoma. In 1994, H pylori was classified as a category 1 carcinogen. H pylori infection can be tested for invasively and noninvasively. The invasive methods include cultivation, histological examination and a rapid urease test. Noninvasive options are the carbon urea breath test, a stool antigen (HpSA) test and a blood antibody test. H pylori is sensitive to betalactam antibiotics. These should therefore be the essential part of the treatment; the instances of resistance are rare. Should the patient be allergic to betalactam antibiotics, nitroimidazoles can be used instead. H pylori is also sensitive to macrolides. The objective of my bachelor thesis was to acquire practical knowledge necessary for the correct processing of stool and serum samples in laboratory practice. I also intended to describe current trends in diagnosis and treatment of H pylori infection, together with the infection rates depending on age, sex and the season of the year. The findings were discussed in the context of relevant academic literature. Finally, I monitored the ways in which gastroduodenal ulcer disease caused by H pylori infection is diagnosed and treated by gastroenterologists in České Budějovice. The collection of the data for quantitative research was carried out between 1 January 2012 and 31 December 2012 in the microbiological laboratory Synlab czech s.r.o. in České Budějovice, which covers the whole of the South Bohemian Region. The samples were supplied mostly, but not exclusively, by GPs, and two methods of medical examination (euroSCREEN HP and EIA Helicobacter MONO IgG) were used. EuroSCREEN HP is based on the stool antigen (HpSA) detection, EIA Helicobacter MONO IgG is an immunoenzymatic method detecting IgG antibodies against H pylori in human serum or plasma. The data for qualitative research were collected in gastroenterologic ambulances in České Budějovice. Guided semi-structured interviews were carried out with one doctor in each ambulance. The acquired data were then processed as case studies and used to obtain categorization tables. The quantitative research confirmed all three hypotheses subject to evaluation. Higher age groups were found to have higher infections rates. However, no effect of either sex or the season of the year on the infection rates was registered. The qualitative research showed that gastroduodenal ulcer disease is most frequently diagnosed by České Budějovice gastroenterologists by the means of a biopsy check during gastroscopy. The samples are then sent to a microbiological laboratory for cultivation, histological examination and a rapid urease test. H pylori infection is usually treated by the standard triple therapy: amoxicillin, clarithromycin and a proton pump inhibitor. In case of hypersensitivity to betalactam antibiotics clarithromycin, a proton pump inhibitor and metronidazole are used instead. Occassional resistance to metronidazole and clarithromycin was reported. In these situations, cultivation is carried out in order to determine the sensitivity to antibiotics. The effects of the eradication treatment are evaluated by the means of a biopsy check during gastroscopy 6-8 weeks after its application. The samples are analysed in a microbiological laboratory. Some gastroenterologists also use a stool antigen (HpSA) test.
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Development of antibiotic resistance in the region Písek in 2000-2010
MAREŠOVÁ, Lucie
This bachleor´ s dissertation is aimed to the developement of antibiotical resistance by choosed kinds of bacteria, particulary Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae in the region of Písek and also in the whole Czech Republic during the period 2000-2010. There is described matter of the antibiotical resistance, antimicrobial agents and also information about the EARS-Net system in the beginning of this work. The practical part contains the evaluation of resistance spread in the region of Pisek according to the data of clinical microbiology of Nemocnice Pisek, the spread of resistance in the Czech Republic according to the EARS-Net and also the consumption of individual groups of antibiotics according to the State Institute for Drug Control. Antibiotical resistance is spreading constantly, for example because of inappropriate usage of the antibiotics or insufficient information about pathogens that cause infectious diseases the most frequently.
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