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The development, constitution and functions of the gland apparatus in schistosome cercariae and endopeptidases in its contents
Titlová, Lucie ; Mikeš, Libor (advisor) ; Konečný, Lukáš (referee)
Flukes of the family Schistosomatidae are blood parasites with two-host life cycles involving aquatic snails as intermediate hosts and avian or mammalian definitive hosts. Cercariae, as invasive aquatic stages of schistosomes, enter the lumen of vessels by penetrating the skin of the definitive host. During their short life, cercariae possess a glandular apparatus consisting of three types of glands with external secretion: penetration glands, escape glands, and a head gland. These glands secrete granules containing, among other things, proteolytic enzymes, which play an important role in the process of penetrating the host's skin, but at the same time they occupy many other functions during the life of the cercaria and other life stages of schistosomes. This thesis summarizes basic knowledge about the anatomy, function and development of the gland apparatus of schistosome cercariae and further focuses on the representation of proteolytic enzymes in these glands, specifically endopeptidases. At the end, it briefly compares the different representation of endopeptidases in some members of the family.
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In vitro cultivation of the trematode species Trichobilharzia regenti
Vrbová, Kristýna ; Kašný, Martin (advisor) ; Skelly, Patrick (referee)
The class Trematoda includes many pathogenic representatives. Main subject of this thesis, avian schistosome Trichobilharzia regenti, is a close relative to the important human pathogen Schistosoma mansoni (family Schistosomatidae). In vitro cultivation of trematodes enables closer understanding of their biology and parasite- host interactions; however, no trematode species has been successfully kept in vitro from the egg stage to the adults producing eggs. Many studies are focused on the problematic of S. mansoni cultivation, but data concerning T. regenti cultivation remain scarce. Only the ability of T. regenti cercariae to transform into schistosomula in vitro was documented, with following survival in a culture medium for a few days. Comparison of eight transformation methods was performed with T. regenti cercariae. Based on the number of tailless cercarial bodies obtained, five transformation methods were selected for further evaluation of the early schistosomula characteristics (glycocalyx shedding, penetration glands emptying and survival in vitro). It was observed that the largest quantity of cercarial bodies can be obtained by using a syringe needle or the BeadBeater cell disrupter. The largest quantity of schistosomula meeting the criteria of early schistosomulum was recorded after...
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