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Monoxenous trypanosomatids of invertebrates
Havlová, Jolana ; Votýpka, Jan (advisor) ; Varga, Vladimír (referee)
The class Kinetoplastea contains free-living and parasitic species. One of the most dominant group within the class is the order Trypanosomatida which includes obligate parasites (Trypanosoma, Leishmania) infecting a wide range of hosts. Some species are serious pathogens of humans and domestic animals and cause considerable losses. However, the majority of trypanosomatids belongs to monoxenous parasites of insect which are usually harmless to their hosts. Monoxenous trypanosomatids predominantly infect Hemiptera and Diptera. This diploma thesis is focused on the detection of monoxenous trypanosomatids in cockroaches captured in the Czech Republic and cockroaches from different breedings. Cockroaches are very suitable mechanical vectors of many different pathogens (including parasites) and are significant health threat for humans and animals. First trypanosomatids in cockroaches were documented at the beginning of the 20th century, but there is no study focused on this topic specifically. Another aim of this thesis is morphological and ultramicroscopic analysis and the study of the host specificity of the recently described species Herpetomonas tarakana, isolated from a cockroach. My findings were partly used in the already published study "Diversity of trypanosomatids in cockroaches and the...
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Sexual transmission of Toxoplasma gondii from males to females: experimental verification using laboratory animal model
Navrátil, Jiří ; Kodym, Petr (advisor) ; Votýpka, Jan (referee)
Toxoplasma gondii is cosmopolitly living parasite which prevalence in human extends to tens of percent. In its life cycle it uses any homoiothermic vertebrate as an intermediate host. The definitive host are felines from Felidae family. The acute phase of infection is medically important in immunocompromised pacients and by its risk of congenital toxoplasmosis in pregnant women who never suffered from this illness before. Infection could have serious and rarely even lethal consequences in both cases. This thesis focuses on experimental verification of theory of sexual transmission of toxoplasmosis from male to female on laboratory mice. Possible transmission was tested in acute phase and latent phase of infection. The result was negative in both cases. Moreover, we observed the parasite's affinity to tissue of organs in male mice by PCR technique. Particularly, our interest was in comparing genital organs with others. It was discovered that lungs and spleen are the most infected organs in acute phase of infection. Toxoplasma was also present in genital organs (especially in epididymis) but not more frequently than in others. We observed statistically significant difference between sexual and non-sexual organs in acute and latent toxoplasmosis - non-sexual organs were more infected in both phases....
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Use of RNAi and CRISPR systems in genetic modifications of parasitic protists
Kaiserová, Veronika ; Votýpka, Jan (advisor) ; Stojanovová, Darja (referee)
In organisms, RNA interference serves as a defence mechanism against foreign nucleic acids. RNAi has a negative effect on translation, via the binding of small non-coding molecules to the complementary region of mRNA, resulting in its degradation. CRISPR, a new method of genetic engineering, is based upon modulating genetic expression via creating double-stranded breaks in target DNA, aided by a ribonucleoprotein complex, consisting of the prokaryotic endonuclease Cas9 and sgRNA. Both of the aforementioned methods can be utilised in functional analysis of proteins and the characterisation of metabolic pathways in organisms of interest. This work summarises the current state of knowledge regarding RNAi and CRISPR and their use in genome editing of parasitic protists.
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Mosquitoes and biting midges as vectors in the Czech Republic
Rádrová, Jana ; Votýpka, Jan (advisor) ; Modrý, David (referee) ; Alten, Bülent (referee)
Insect is the largest and the most diverse class of animals and many species have significant impact to people and his activities, whether positive or negative. Since the late 19th century it is known, that bloodsucking insects can serve as vectors of pathogens, causative agents of many infection diseases. As climate change, the distribution and abundance of arthropods including bloodsucking insects can be affected. Emergence of new vector-borne diseases in Europe is likely to be among the most important effects of global changes. In recent years, several vector-borne diseases affecting humans and domestic animals have (re)emerged and spread in Europe with major health, ecological and socio-economical consequences. For example mosquito-borne West Nile virus affects human and animal health, as well. On the other hand, two newly emerged zoonosis, caused by Bluetongue and Schmallenberg viruses and transmitted by biting midges, affect mainly small domestic ruminants. In the frame of broader projects, two epidemiological and entomological surveys focused on mosquitoes and biting midges as possible vectors of West Nile virus, Bluetongue or Schmallenberg virus were carried out in the Czech Republic. New mosquito and biting midges species were recorded for the Czech Republic, the presence of West Nile...
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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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Biting midges and their patogens
Mračková, Marie ; Votýpka, Jan (advisor) ; Modrý, David (referee)
This thesis deals with biting midges of the genus Culicoides, which are tiny nematoceran insects belonging to the Diptera, and their parasites. Biting midges partake in transmissions of several parasitical organisms of various groups. Most notably, they are the vectors of several pathogenic viruses which might have a serious impact on livestock. However, the thesis deals with detection of parasites belonging to Trypanosomatids and Filarioids related to two independent biting midges collections - from the Czech Republic and from the Central African region. Apart from testing biting midges, there were carried out the tests on the occurrence of the same group of parasites within ruminant hoofed games in the Czech Republic. Our goal was to find out whether the same parasites occur with biting midges and their hosts (hoofed games) and whether biting midges could play a role as vectors. Biting midges are relatively overlooked group of haematophagous insects. Until recently, they had not been paid much attention, which changed with the spread of Bluetongue virus over Europe. This stimulated a widespread monitoring of biting midges in several European countries, including the Czech Republic. This helped to gain a large amount of data about the occurrence of biting midges near livestock. Nevertheless, there is no...
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Visceral leishmaniasis in Ethiopia: transmission and variability
Gelaglie, Aysheshm Kassahun ; Votýpka, Jan (advisor) ; Gradoni, Luigi (referee) ; ÖZBEL, Yusuf (referee)
Leishmaniasis, a protozoan infection caused by Leishmania parasites is a neglected disease affecting millions across the world. It is exhibited by diverse clinical presentations that broadly classified as visceral (VL) and cutaneous (CL) leishmaniasis. Both CL and VL are endemic to Ethiopia, which the later is generally considered as fatal, if left untreated. Leishmania donovani is the sole agent of Ethiopian human VL. In Africa, the worst VL affected regions are found in Sudan and Ethiopia. VL is considered as an endemic and at the same time emerging disease in north, northwest, south and southwest with sporadic cases in Eastern Ethiopia. The epidemiology is more or less associated with seasonal migration to endemic areas and HIV/AIDS. The transmission of CL in Ethiopia is known to involve zoonotic cycle while VL transmission isn't clearly understood despite traditional generalization of anthroponosis in East African platform. The aim of this dissertation is to determine VL transmission cycle and study variability L. donovani and P. orientalis in Ethiopia. Studies on human and non-human hosts were conducted to determine the transmission dynamics. To assess the role of symptomatic and asymptomatic L. donovani infected persons in the epidemiology of VL, a community based cohort was conducted. As the...
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The Influence of Parasites on the Sex Ratio
Benešová, Jana ; Kaňková, Šárka (advisor) ; Votýpka, Jan (referee)
Changes of the sex ratio in favour of one sex or the other may be caused by various factors. These changes have proximate causes, while some may even have ultimate causes. One of the factors affecting the sex ratio is parasitisation. The parasite manipulates the sex of the offspring of their hosts intentionally, or as a so-called side effect of its actions. The major role in deviated formation of the sex ratio is often endocrine and immune systems. Many studies are also concur with the Trivers-Willard hypothesis on a lower sexual index in the poor condition of females. Key words: sex ratio, parasite, Trivers-Willard hypothesis, manipulation hypothesis, sex hormones, immunity
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Comparison of molecular methods for identification of sand flies
Gottfried, Vítězslav ; Dvořák, Vít (advisor) ; Votýpka, Jan (referee)
Phlebotomine sand flies are vectors of important human and veterinary infectious diseases which are distributed mainly in subtropical and tropical areas around the world. The most important transmited infection is leishmaniosis. Over 900 species and subspecies of Phlebotominae subfamily have been described and classified into 32 genera. Their taxonomy has not been fully resolved yet. Morphological identification of each species is time-consuming, some species are even morphologically undefinable. For these reasons the molecular methods of identification are used. The methods described in this bachelor thesis study molecular structures and etologic displays. All these methods had been used for species identification of sand flies and are followed by examples of usage, adventages and disadvantages.
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Cospeciation of bird ectoparasites
Gajdošová, Magdalena ; Munclinger, Pavel (advisor) ; Votýpka, Jan (referee)
In a case when two taxa are ecologically very closely related, speciation in one of them may induce speciation in the other one. This phenomenon is called cospeciation. Host specific parasites and their hosts are one of the systems where cospeciation has been frequently studied. Birds and their ectoparasites traditionally serve as a model system. Up to now dozens of cospeciation studies have been done on birds and their ectoparasites by comparing their phylogenetic trees. This work reviews the results of these studies and evaluates the possible effect of ecological and other factors. Cospeciation appears to take place often among birds and their permanent ectoparasites. 64% of the performed studies showed significant cospeciation. The rate of cospeciation varies greatly between different taxa. Some ecological aspects seem to play prominent role, especially those that provide dispersal opportunities to parasites.
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