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Dermatophytes isolated from the hair of free-living rodents
Žárová, Štěpánka ; Čmoková, Adéla (advisor) ; Mašínová, Tereza (referee)
Dermatophytes (order Onygenales, Ascomycota) are microscopic filamentous keratinophilic fungi that can cause skin infections known as dermatophytosis. The most diverse but not very studied genus Arthroderma has been revised recently (Míková 2018) which was essential for further research. This genus comprises mostly species with a supposed reservoir in soil. Lack of information about their ecology and frequent isolation of some species from the hair of free- living mammals (mainly rodents) may testify a strong host association. Rodents could thus represent the hidden reservoir of this species. For this thesis, I have chosen three ecologically distinct rodent species: Mus musculus, Apodemus flavicollis, and Clethrionomys glareolus. I obtained the material by brushing the hair of asymptomatic individuals and used this material for cultivation on selective medium. I identified the isolates of dermatophytes (n = 30) using molecular methods. I used sequences of three highly variable loci (ITS, tubb a tef1α) to incorporate these isolates in the phylogenetic analysis based on the monography of the genus Arthroderma (Míková 2018). I characterized the phenotype of selected strains based on morphological and physiological data including the ability to utilize keratin and the production of siderophores. The...
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Dermatophytes isolated from the hair of free-living rodents
Žárová, Štěpánka ; Čmoková, Adéla (advisor) ; Mašínová, Tereza (referee)
Dermatophytes (order Onygenales, Ascomycota) are microscopic filamentous keratinophilic fungi that can cause skin infections known as dermatophytosis. The most diverse but not very studied genus Arthroderma has been revised recently (Míková 2018) which was essential for further research. This genus comprises mostly species with a supposed reservoir in soil. Lack of information about their ecology and frequent isolation of some species from the hair of free- living mammals (mainly rodents) may testify a strong host association. Rodents could thus represent the hidden reservoir of this species. For this thesis, I have chosen three ecologically distinct rodent species: Mus musculus, Apodemus flavicollis, and Clethrionomys glareolus. I obtained the material by brushing the hair of asymptomatic individuals and used this material for cultivation on selective medium. I identified the isolates of dermatophytes (n = 30) using molecular methods. I used sequences of three highly variable loci (ITS, tubb a tef1α) to incorporate these isolates in the phylogenetic analysis based on the monography of the genus Arthroderma (Míková 2018). I characterized the phenotype of selected strains based on morphological and physiological data including the ability to utilize keratin and the production of siderophores. The...
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Verification of species boundaries in clinically relevant Arthroderma species
Míková, Ivana ; Hubka, Vít (advisor) ; Dobiáš, Radim (referee)
The genus Arthroderma contains predominantly geophilic dermatophytes (naturally occuring in soil). Some species, especially those from Trichophyton terrestre complex, cause human and animal dermatomycosis. In the past, the species boundaries were determined mainly on the basis of biological species concept using in vitro mating experiments. But these nearly 70-years-old findings have not been tested by means of modern taxonomic methods. In total 194 species of the genus Arthroderma (including all available ex-type strains) originating predominantly in USA, Canada and Europe were studied in this thesis. They were mostly isolated from soil (n = 77), animals (n = 50), human clinical material (n = 41) and cave sediment (n = 9). The main goal of the thesis was to elucidate the species boundaries between species A. insingulare, A. lenticulare and A. quadrifidum, that were classified into the T. terrestre complex because of their seemingly identical asexual stage. Further, this work aimed to resolve the relationship between Arthroderma species using the multigene phylogeny and clarify which species are clinically relevant. A multigene phylogeny of the genus Arthroderma was based on the sequences of the ITS rDNA region, β-tubulin (TUB2) and translation elongation factor 1α (TEF1α) genes. The genus...
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Molecular methods used for taxonomy and epidemiology of dermatophytes
Čmoková, Adéla ; Hubka, Vít (advisor) ; Hamal, Petr (referee)
In my bachelor thesis I have dealt with the role and aplication of the molecular methods in the taxonomy and epidemiology of the dermatophytes and the question of the species concepts in dermatophytes. In the first part, I focused on the evaluation of the advantages and disadvantages of the recent species concepts and their problematic application in dermatophytes. The second part is focused on the molecular methods that used genetic markers for phylogenetic analysis and species delineation within dermatophytes, e.g. the PCR-RFLP method, PCR-fingerprinting and DNA sequencing. I have evaluated the dicrimination power of the particular DNA sequence loci to distinguish closely related species. In the last part, I have summarized the molecular methods that have been used in the typization at the intraspecific level, e.g. microsatelite analysis, PCR-fingerprinting, multilocus sequence typing.
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