|
|
Molecular-epidemiological analysis of Mycobacterium tuberculosis strains isolated in the West-Bohemian Region of the Czech Republic including detailed characterisation of anti-tuberculosis drugs-resistant strains
Amlerová, Jana ; Hrabák, Jaroslav (advisor) ; Čermák, Pavel (referee) ; Růžička, Filip (referee)
Molecular-epidemiological analysis of Mycobacterium tuberculosis strains isolated in the West-Bohemian Region of the Czech Republic including detailed characterisation of anti-tuberculosis drugs - resistant strains MUDr. Jana Amlerová Abstract Tuberculosis is contagious infectious disease that embodies significant epidemiological and clinical problem worldwide. Tuberculosis incidence differs considerably in various regions of the world but even the countries with low incidence engage strongly in epidemiology of tuberculosis. Tuberculosis belongs to one of the priorities of WHO, cooperation in this matter takes place on a global scale. Tuberculosis is a social illness; accordingly, the countries with high occurrence of tuberculosis are classified as developing countries. Mainly in Africa, there is the situation being complicated by coexistence of HIV. Generally, Europe represents a region with low incidence of tuberculosis. The Czech Republic is a country with the lowest incidence in the world with less than five new cases per 100 000 inhabitants every year. This situation is among others result of high-level tuberculosis surveillance and effective application of epidemiological arrangements based in legislation. This dissertation thesis examines several fields of tuberculosis, mainly focused on modern...
|
|
|
Molecular epidemiological analysis of carbapenem resistant isolates of Enterobacteriaceae and Pseudomonas spp.
Šrámková, Anna ; Hrabák, Jaroslav (advisor) ; Kolář, Milan (referee) ; Gniadkowski, Marek (referee)
Currently, the development of bacterial resistance is one of the major healthcare problems. Especially, the significant continuous increase of carbapenem-resistant Gram-negative bacteria, which most often affected seriously ill hospitalized patients, is a cause for great concern. Worldwide dissemination of carbapenemase-encoding genes is largely associated with mobile genetic elements and the clonal spread of high-risk clones. The dissertation thesis is focused on a molecular-epidemiological mapping of carbapenemase-positive Gram-negative isolates detected in hospital settings throughout the Czech Republic. Since 2015, a significant increase of carbapenemase-producing Enterobacteriaceæ (CPE) was detected in our country, mainly attributed to the dissemination of OXA-48 and NDM enzymes. Studies focusing on the first big outbreaks as well as sporadic cases of OXA-48 and NDM carbapenemases were performed. Results showed that blaOXA-48-carrying plasmids, which are derivatives of the archetypal IncL plasmid pOXA-48 originally described in Turkey, play a major role in the dissemination of OXA-48 enzymes in Czech hospitals. This finding is in agreement with the data from previous studies reported worldwide. The study of NDM-positive isolates revealed that IncX3 plasmids are the main factor contributing to the...
|
|
|
Development and Validation of Methods for Typing of Bacteria by MALDI-TOF Mass Spectrometry
Chudějová, Kateřina ; Hrabák, Jaroslav (advisor) ; Dolejská, Monika (referee) ; Nyč, Otakar (referee)
1 ABSTRACT Healthcare-associated infections represent a significant cause of morbidity and mortality in hospital settings. The risk of nosocomial infection differs significantly in different group of patients, depending on the character of their primary illness, the co-morbidities, the type of care provided, the length of hospitalization, or the medical procedures used. Artificial surfaces such as central venous catheters, shunts, urinary catheters, valve and joint replacements or controlled lung ventilation play a major role. The majority of nosocomial infections is caused by several representative of Enterobacteriaceæ family, Pseudomonas spp., Acinetobacter spp., or some Gram-positives, especially Staphylococcus and Enterococcus spp. This is largely due to their ability to retain and transfer different types of resistance to antibiotics. The identification and subtyping of these pathogenic microorganisms is an essential tool of modern public health infectious disease surveillance not only for appropriate and efficient treatment of infections, but also in case of an outbreak. Understanding clonal continuity among investigated strains is essential to determine the source and routes of infections, confirm or rule out outbreaks, trace cross-transmission of healthcare-associated pathogens, or recognize virulent...
|
|
| |
|
|
Molecular typization of isolates from Arthroderma benhamiae complex, a zoonotic agent of epidemic dermatophytosis in Europe
Čmoková, Adéla ; Hubka, Vít (advisor) ; Hrabák, Jaroslav (referee)
Arthroderma benhamiae has been almost unknown among clinical mycologists but it is a cause of around 40 % of dermatophytic infections according to current studies in the Czech Republic. The species is primarily transmitted to humans from guinea pigs and other rodents. The epidemiological situation is similar in other countries in Central and Western Europe. The reason of significant increase in the incidence of infections has not been identified yet, and no sufficiently informative molecular markers have been developed for typification of the species that could help to resolve the cause of this problem. For the purposes of this study, isolates (n=268) from cases of human and animal dermatophytoses from the Czech Republic, Germany, Belgium, Switzerland, Italy, Japan and USA were selected. Ten variable microsatellite markers were developed and sequence analysis of two genetic loci (ITS rDNA and gpdh gene) were performed to reveal intraspecific variation. Phenotype was also studied at the level of micro- and macromorphology of the strains and growth parameters at several temperatures and on several cultivation media. Mating type idiomorph of each isolate was determined and mating experiments were performed by crossing pairs of genetically related as well as genetically distant strains. Sequence...
|
|
|
Proteolytic Enzymes of Vegetative Forms and Spores of the Bacterium Paenibacillus larvae
Hrabák, Jaroslav ; Martínek, Karel (advisor) ; Kotyza, Jaromír (referee) ; Titěra, Dalibor (referee)
Due to the high resistance of the spores, the bacterium Paenibacillus larvae is the most dangerous bacterial pathogen of the honey bee (Apis mellifera). Thanks to its biological properties and restricted pathogenicity, this bacterium can be used as a model organism to study gram positive sporulating aerobic rods. This work is focused on completing information about secreted proteases of this bacterium and in a study of proteases bound in a spore structure. MYPGP medium was used for the cultivation of P. larvae. In this medium, lysis of the culture was shown after 40 hours of cultivation. The pH of the medium decreased below 6.4 by lysis. The induction of temperate bacteriophage BLA was detected as a causative agent of this lysis. A new sporulation medium called HCBB agar was proposed for the sporulation of P. larvae. In comparison with HCBB agar with MYPGP agar by 31 strains of P. larvae stored in our collection, HCBB agar was evaluated as an appropriate sporulation medium with a median of sporulatin 4.2 ' 106 spores per cm2 in aerobic conditions and 5.65 ' 106 spores per cm2 in aerobic conditions with 10 % CO2. For purification of the secreted proteases, a one-day culture incubated at room temperature was used. Optimal purification of 87/74 kDa and 42/40 kDa proteases was observed after application of this...
|
|
| |
guest ::
RSS feed.