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Virulence factors of the Trichophyton benhamiae complex
Machová, Lenka ; Čmoková, Adéla (advisor) ; Labuda, Roman (referee)
Dermatophytes are a group of fungi, some of which can cause skin diseases in humans and animals due to their ability to degrade keratinized tissue. Representatives of this group also include strains from the Trichophyton benhamiae complex, known to cause dermatophytosis especially of small rodents and rabbits. In the last decade, one of four populations of this complex has spread epidemically across Europe among guinea pigs and their breeders. To answer the question what stands behind the successful spread of this population, the gene expression and production of volatile organic compounds of epidemic and non-epidemic populations of T. benhamiae was investigated. Gene expression of three strains from each population was studied during growth in liquid medium and on ex vivo mouse skin models prepared according to a newly optimized protocol. RNAseq and RT-qPCR methods were chosen for the gene expression analysis. Based on the literature and the results of RNAseq preliminary analysis, several genes were selected for which specific primers were designed. The spectra of the produced volatile organic compounds of the same strains growing on sheep wool in vials were analyzed by GC-MS. While non-epidemic populations did not differ in gene expression and production of volatile organic compounds, the...
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Antifungal resistance mechanisms in dermatophytes
Kolarczyková, Daniela ; Hubka, Vít (advisor) ; Kuklová, Ivana (referee)
For the treatment of superficial fungal infections (dermatophytosis) is available a wide spectrum of antifungals from various chemical groups. These antifungals are mainly focused on various steps of ergosterol synthesis, thereby disrupting the cell membrane (allylamine, azole and morpholine antifungals) and on microtubule function (benzofuran antifungals). Despite the fact that the treatment of dermatophytosis is often associated with long-term exposure of the fungus to antifungals (weeks or months), until recently antifungal resistance in dermatophytes has been considered rare. However, current studies have shown the incidence of chronic infections, reinfection and treatment failures due to emerging resistance to some commonly used antifungals. The most serious problem today is the spread of resistance to terbinafine where the molecular principles are founded in the structural changes in the squalene epoxidase enzyme (SQLE). The increase in the incidence of this and other resistances is currently alarming especially in India, while the situation in Europe and America is in terms of dermatophyte susceptibility still quite favorable. The aim of this thesis is to summarize our knowledge of antifungal resistance in dermatophytes and their molecular principles. The thesis further summarizes the...
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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...
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Laboratory diagnosis of dermatophytosis
Drnková, Nela ; Vejsová, Marcela (advisor) ; Křivčíková, Lucie (referee)
Author: Nela Drnková Title of the bachelor thesis: Laboratory diagnosis of dermatophytosis Charles University in Prague, Faculty of Pharmacy in Hradec Králové Degree course: Medical laboratory technician My bachelor thesis is focused on laboratory diagnosis of dermatophytes. The purpose of this work is created summary of laboratory methods, which are used for diagnosis of dermatophytosis. Beginning of thesis is given to common characteristics of dermatophytes, taxonomony, nomenclature and morphology of individual genera. The big part of thesis creates summary of laboratory methods. There are described individual types of microscopy, cultural techniques, molecular methods and immunological methods. The end of the thesis is dealted with infections, which are caused by dermatophytes and their treatment. Light microscopy and culture are used most frequently. Key words: dermatophytes, Trichophyton, Microsporum, Epidermophyton, laboratory diagnosis, tinea
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