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Fleas as hosts and vectors of bacteria
Hovorková, Jana ; Hammerbauerová, Iva (advisor) ; Myslivcová Fučíková, Alena (referee)
Fleas (Siphonaptera) are worldwide significant ectoparasites and vectors of several human pathogens. The most serious flea-born infections include plague, rickettsiosis and bartonellosis caused by Yersinia pestis, Rickettsia spp. and Bartonella spp. I have focused on the microbiome of fleas with an emphasis on bacteria which are transmitted by fleas or are pathogenic, mutualistic or commensal in relation to their flea host, from the point of view of their mutual interactions. The composition of the flea microbiome can be influenced both by mutual interactions between individual bacteria and by many different factors, which include, for example, the species or gender of flea or its host, humidity and temperature of the environment or geographic location.
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Phylogenetic and seasonal patterns in the microbiome of mosquito vectors
KLEIN, Amelie
The aim of this thesis was to identify phylogenetic and seasonal patterns in mosquitoes' microbiome. Thereby, the season around summer was targeted and the species Culex pipiens with the two forms pipiens and molestus as well as their hybrid form were of interest. For the microbiome analysis, the 16s rRNA gene was targeted in individual samples.
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Impact of endosymbiotic bacteria on the capacity of host spiders (Araneae) to provide ecosystem services
Gloríková, Nela ; Řezáč, Milan (advisor) ; Tropek, Robert (referee)
The impact of the microbial community as well as individual strains of endosymbiotic bacteria on spider hosts has only begun to be increasingly studied in the last 20 years. This is primarily due to new molecular methods and devices, but on the other hand also to a growing desire to unravel the mechanisms behind the ability of spiders to provide ecosystem services. Their unique contribution lies in their high diversity, their generalist hunting strategy, and their efficient long-distance dispersal called ballooning. However, their abilities are possibly affected by the tiny organisms inhabiting their tissues - from the haemolymph to the digestive tract and the reproductive organs. In this work, attention is paid to the aspects that are influenced or manipulated by microbes for the purpose of their own transmission. Studies investigating known reproductive manipulators such as Wobachia, Cardinium or Rickettsia are summarized. The work summarizes recent findings in the areas of the impact of endosymbiotic bacteria on metabolic pathways and nutritional support, but also on behavioral aspects such as predatory/antipredatory behavior, defense against parasitoids or pathogens, and dispersal or avoidance of stress. Information about spiders is also related to knowledge about other invertebrates. Keywords:...
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Comparison of reproductive parameters of Central European populations of the critically endangered Hermit butterfly (Chazara briseis)
Štochlová, Tereza ; Sedláček, Ondřej (advisor) ; Kadlec, Tomáš (referee)
The Hermit butterfly Chazara briseis is a species from the family Nymphalidae, inhabiting mostly short-stemmed dry steppes. In Central Europe, it is critically endangered. It is therefore currently the subject of many conservation activities, including reintroductions. In such translocations of individuals, it is important that the native and source populations be as closely related as possible in all respects. Therefore, individuals of two forms of this species, Ch. briseis pannonica (Austrian population) and Ch. briseis bataia (Czech population) were bred and their reproductive characteristics were recorded and the differences between the two forms were observed. During two seasons 5 Austrian and 8 Czech females were successfully bred. The Austrian and Czech populations differed mainly in the timing of adult hatching and the beginning of the laying of eggs by females - Austrian individuals are phenologically shifted to one week to 14 days earlier. Individual populations of the same species may also differ from each other in the presence of Wolbachia pipientis. This bacterium can affect the sex ratio in a population as well as the reproduction behavior of individuals. There was a suspicion of its presence in the Czech population. Therefore, a part of the Czech population was treated with...
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Bacteria genus Asaia and Wolbachia in sandflies
Sovová, Kristina ; Volf, Petr (advisor) ; Bilej, Martin (referee)
Phlebotomine sand flies are proven vectors of many pathogens including parasites of genus Leishmania. Leishmania develop in sand fly midgut which is colonized also by many others microorganisms, creating rich community known as gut microbiota. The presence and composition of gut microbiota affect sand fly mortality, but also development of transmitted pathogens. In contrast to mosquitoes, sand fly gut microbiota is not well studied. This thesis focuses on bacteria of the genera Asaia and Wolbachia and their potential impact on Leishmania in sand fly midgut. Thesis reports the first finding of Asaia sp. and Wolbachia sp. in sand flies from Balkan penninsula - hotspot for visceral leishmaniasis and phleboviruses. In 273 individuals from subgenera Larroussius were Asaia sp. and Wolbachia sp. detected with infection prevalence 2,5 % and 8,4 %, respectively. In addition, laboratory-reared sand flies were tested for presence of these bacteria: from twelve studied colonies, only Phlebotomus perniciosus was infected by Wolbachia sp. Then, we focussed on elimination of Wolbachia sp. from this laboratory colony with the aim to use Wolbachia-negative sand flies in future experiments with Leishmania. The final part of the thesis was dedicated to bacteria of the genus Asaia (specifically A. krungthepensis),...
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Symbiotic bacteria of the genus Wolbachia in sand flies and mosquitoes.
Rehbergerová, Markéta ; Dvořák, Vít (advisor) ; Jančářová, Magdaléna (referee)
Bacteria of the genus Wolbachia (Proteobacteria, Rickettsiales, Rickettsiaceae) are maternally inherited intracellular symbionts of many species of arthropods (Arthropoda) and filarial nematodes (Nematoda, Secernentea). Due to the ability of Wolbachia to induce reproductive anomalies in their hosts and to reduce their infection by pathogenic organisms and viruses, they are profoundly studied. This bachelor thesis is a summary of available information regarding interactions of Wolbachia with mosquitoes (Diptera, Culicidae) and sand flies (Diptera, Psychodidae, Phlebotominae), vectors of many important infectious pathogens, and possibilities of their use in the control of pathogen transmission. Key words: Wolbachia, Phlebotominae, Culicidae, vector-borne diseases, symbiosis, vector control method
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Interactions "symbiotic" or "parasitic" bacteria Cardinium and Wolbachia with mites (Acari)
Hejdánková, Sylvie ; Hubert, Jan (advisor) ; Smrž, Jaroslav (referee)
The thesis reviews known information and findings describing the interactions of bacteria Candidatus Cardinium hertigii (Sphingobacteriales: Flexibacteraceae) and Wolbachia pipientis (Rickettsiales: Rickettsiaceae) with mites (Acari). Both bacteria are known as symbionts or reproductive parasites and has been found in many species of arthropods. Here, the morphological characterization and localization of bacteria in their hosts and ecological interactions are revised and described. The main known interactions between these bacteria and mites lead to cytopasmic incompatibility, parthenogenesis, feminization and hybrid breakdown. The mites can be infected by both bacteria (Cardinium and Wolbachia), i. e. double infections, or by several strains of bacteria, i. e. multiple infections. The possible aplication of symbiotic/parasitic bacteria in the control of pest mites is discussed. The studied bacteria are suitable models for desription of the arthropod bacterial interactions.
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Evolution and genomics of symbionts in Hippoboscidae
ŠOCHOVÁ, Eva
Obligately blood-sucking parasites harbour symbiotic bacteria providing them B-vitamins and cofactors missing from their blood diet. Within Hippoboscoidea group (parasites of birds and mammals), tsetse flies as medically important vectors have been studied extensively while bat flies and louse flies tend to be neglected. This thesis is composed of two complementary manuscripts focused on phylogeny and origin of bacterial symbionts in Hippoboscidae family (manuscript 1) and their genome evolution (manuscript 2). First, phylogenetic approach was employed to determine lineages of obligate and facultative symbionts present in this group. Second, genomic and phylogenomic analyses were carried out to better understand evolution of obligate endosymbionts from the Arsenophonus genus in this group. Results of the two studies indicate that relationships between Hippoboscoidea and their symbionts are extremely dynamic with frequent replacements of obligate symbionts. This hypothesis is supported by both phylogenetic and genomic evidence, in particular, Arsenophonus endosymbionts of Hippoboscidae represent several distinct lineages (of likely different ages) with noticeable differences in genome features and metabolic capabilities. The data presented in this thesis thus greatly extend our knowledge about evolution and genomics of symbiotic bacteria in Hippoboscidae and bloodsucking hosts in general.
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The intracellular symbionts of blood-feeding Diptera group Hippobosccoidea
ŠOCHOVÁ, Eva
Blood-sucking parasites from the Hippoboscoidea group (Insecta: Diptera) harbor symbiotic bacteria providing them with B-vitamins and cofactors missing from their blood diet. Although including medically important vectors such as tsetse flies, evolutionary history of symbiosis in the whole group is poorly understood. This thesis is focused on analysis of symbionts in the Hippoboscidae family (parasites of birds and mammals). Phylogenetic approach was employed to determine lineages of obligatory and facultative symbionts present in this group. Results of the study indicate that relationships between Hippoboscoidea and their symbionts are extremely dynamic with frequent replacements of obligate symbionts. To which extent is this dynamic evolutionary history of symbiotic systems in Hippoboscoidea caused by features of their parasitic lifestyle (e.g. host switches from mammals to birds) will be an interesting question for further studies.
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