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Trypanosomes of green frogs (genus Pelophylax)
Poloprutská, Klára ; Votýpka, Jan (advisor) ; Modrý, David (referee)
Anuran trypanosomes are the first ever observed and described trypanosomes and Trypanosoma rotatorium from frogs of the genus Pelophylax is a type species of the genus Trypanosoma. Despite the early discovery, they are being neglected in terms of current descriptive studies when compared to other trypanosomes, although their diversity and prevalence in anurans are quite high. Anuran trypanosomes, which are significantly larger than their mammal relatives, display a high rate of polymorphism and pleiomorphism; however, without any explanations. Because of the amphibious nature of frogs, the vectors of anuran trypanosomes are both aquatic leeches and terrestrial bloodsucking insects. This thesis which aims at widening the scope of knowledge about this neglected group of trypanosomes focuses on trypanosomes from frogs of the genus Pelophylax found in Central Europe and the Balkan Peninsula. An overall prevalence of 71% was found in 981 individuals and a total of thirteen trypanosome species were detected, eight of which are new to science. Significantly higher diversity was found in frogs originating from the Balkan Peninsula; however, no host specificity of trypanosomes was detected. It was not possible to unambiguously prove the relationship between morphospecies and genospecies. On the contrary, I...
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Mosquito flaviviruses in the Czech Republic
Majerová, Karolina ; Votýpka, Jan (advisor) ; Kopecký, Jan (referee)
Flaviviruses (genus Flavivirus, family Flaviviridae) includes a number of medically and veterinary important arboviruses. Most of them are transmitted by mosquitoes, such as West Nile virus, yellow fever virus, dengue virus or Zika virus. In the last decade, there has been discovered number of flaviviruses which have not known vertebrate host. They are called insect-specific flaviviruses (ISFs). These viruses have been detected in dipteran insects (mostly in mosquitoes) from all over the world. It seems they induce no pathogenic changes even in insect and they are not able to infect any vertebrate cells. However in some recent studies has been shown that some ISFs could influence the replication of other medically important flaviviruses in mosquito cells. In addition, they probably represent an ancestrial lineage of the family Flaviviridae and further studies focused on them could help to clarify which characteristics of flaviviruses enable them to infect vertebrates. There is not a lot of information about the ecology of ISFs and it is suggested that most ISFs have not been discovered yet. Main goal of this thesis was to detect ISFs in mosquitoes in the Czech Republic, where have not been made any exstensive research of these viruses yet. In case of discover some undiscribed ISFs we wanted to characterize...
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Sand flies as hosts of monoxenous and dixenous trypanosomatids
Vondráček, Oldřich ; Votýpka, Jan (advisor) ; Jirků, Kateřina (referee)
Phlebotomine sandflies are blood sucking Dipteran and important vectors of various patogens, especially leishmania parasites (Trypanosomatida, Leishmaniinae). Apart from the genus Leishmania they also transmit variety of other parasites and they are considered to be vectors of trypanosomes (genus Trypanosoma) and hosts of some monoxenous trypanosomatids. This Master thesis is focused on the occurrence and development of mono- and dixenous trypanosomatids (other than the genus Leishmania) in sandflies. We studied experimental infections of various species of sandflies and mosquitoes by two species of trypanosomes and one species of monoxenous parasite (Strigomonas galati). All three studied trypanosomatid species were isolated from sandflies. Further concern of the thesis is the transmission of both species of trypanosomes from sandflies to vertebrate hosts and the transmission of monoxenous parasite between insect hosts and also morphological changes of parasite cells during the development in a culture and in the insect and vertebrate hosts.
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