National Repository of Grey Literature 90 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
The effect of temperature and moisture on biology of house dust mites Dermatophagoides farinae
Vacková, Tereza ; Hubert, Jan (advisor) ; Votýpka, Jan (referee)
The biology and allergen production of dust mites are significantly influenced by hygrothermal factors (temperature and humidity). This thesis summarizes studies dealing with the effect of temperature and humidity on the population growth of mites species Dermatophagoides farinae, their metabolism (represented by their respiration rate) and migration patterns within a temperature gradient (simulating conditions in the vertical section of a mattress). D. farinae colonies reared at different combinations of temperature and humidity (in the range of 15-35 řC and 62-94% RH) showed the average highest and stable population growth at 28 řC and 85% RH. The highest CO2 production of this species was - within studied temperature (15-35 řC) - observed at 30 řC. At this temperature there were two respiration peaks at RH 90% (smaller peak) and 65% (larger peak). Within a temperature gradient (19-41 řC), fed mites were most often found in the sector with a temperature range of 32-36 řC. This phenomenon was observed in both experimental designes: in a stable (24 h) temperature gradient, but also in experiment with 5 days of alternating cycles of the same gradient (8 h / day) and room temperature (16 h / day). Conversely, the highest number of non-feeding mites was found in the sector with a temperature range of...
Parasitic strategies based on behavioral manipulation of the arthropod host
Janovská, Kateřina ; Straka, Jakub (advisor) ; Votýpka, Jan (referee)
It is well known that parasites can alter the host's behaviour for their benefit or the benefit of their offspring. Arthropods often fall victim to these parasites. Although the parasites of Arthropods come from many different groups (e.g., helminths, insects, fungi, viruses, etc.), we can find some similarities in their strategies. The specific methods and processes of behavioural manipulation are unique to each parasite and depend on whether the arthropod is the parasite's final host or an intermediate host/vector. However, they often lead to the same goal, e.g., to be eaten by another host, to allow the parasite to reproduce or to protect the parasite's offspring. Whether these changes in the host's behaviour are a part of the parasite's life strategy or only a manifestation of an adaptive response of the host remains a question. This thesis discuss specific cases of behavioural manipulation in parasitized arthropods and the common motives parasites use in manipulation. Keywords: behaviour manipulation, Arthropods parasite, parasitoid, host's behaviour, host- parasite interaction, adaptive response
Bee trypanosomatids and their interactions with pollutants
Pařízková, Kamila ; Votýpka, Jan (advisor) ; Krejčí Bruce, Alena (referee)
Honeybees (Apis mellifera) are highly valued worldwide for their products, but also as pollinators of crops and wild plants. Due to the close proximity of bees in the beehive and their foraging habits, a large number of pathogens that weaken the bee colonies are spread both inside and between colonies. In recent decades, high annual losses of bees have been recorded, which still do not have a clear explanation. The sudden loss of bees (known as colony collapse disorder) is likely due to the interaction of multiple factors at once. A large part of the problem is attributed to viral diseases and some parasitic organisms; parasites of the Trypanosomatida group play an uncertain role. A member of this group, Crithidia bombi, is considered a problematic inhabitant of the digestive tract of bumblebees, which can cause serious complications. Close relatives, C. mellificae and Lotmaria passim, parasites of honeybees, are sometimes associated with their higher mortality. Pesticides, whose effects can be very toxic, have also come to the forefront in assessing bee losses, and most pesticides have therefore been banned in the EU. This thesis examines the prevalence, infection development, and host specificity of monoxenous trypanosomatids in bees and their pesticide interactions. A total of 26 species of...
Rodent trypanosomes: occurrence, development and transmission
Valsová, Iveta ; Votýpka, Jan (advisor) ; Kodym, Petr (referee)
Trypanosomes of the subgenus Herpetosoma are considered highly host-specific and nonpathogenic to their hosts. They are commonly found in rodents (and some insectivores), and fleas are believed to be their vectors. Around 50 trypanosome species have gradually been assigned to this subgenus, mainly based on the morphology of blood forms and their host specificity. However, due to the application of molecular methods, this number is beginning to increase. This thesis aims to investigate the prevalence and evolution of trypanosomes of the subgenus Herpetosoma in different mammalian hosts and their fleas in the Czech Republic. In total, samples from 17 mammalian species (mainly rodents) were tested for the presence of trypanosomes; only three species were found: with 1% prevalence Trypanosoma in the bank vole (Clethrionomys glareolus) similar to T. microti (typical for the field vole, Microtus agrestis), with 4% prevalence T. grosi in field mice (Apodemus spp.), and with 40% prevalence Trypanosoma sp. B08-471 in the European edible dormice (Glis glis). This trypanosome species was also detected in the flea Ceratophyllus (Monopsyllus) sciurorum, which is a typical ectoparasite of edible dormice. In fleas, the development of trypanosomes and also commonly occurring monoxenous trypanosomatids of the genus...
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...
The differences in the virome of different populations of honey bee (Apis mellifera)
Kadlečková, Dominika ; Tachezy, Ruth (advisor) ; Votýpka, Jan (referee)
European honey bee (Apis mellifera) is major pollinator for agriculture and vital for food production. Large number of viruses infecting A. mellifera have been discovered over the years, but it isn't yet known if they are pathogenic for their host. However, presence of non-viral pathogens like Varroa destructor can greatly increase their virulence and have fatal consequences for the colony. The aim of this study was to test and verify robustness of the method for virome detection on healthy honey bees from the Czech Republic. Last but not least we aimed to detect non-viral parasites and correlate their presence with detected viruses. We have successfully identified large number of viral sequences from different viral families. Viral composition was found to be influenced mainly by colony from where the honey bees were collected. That was mainly given by a large amount of bacteriophages in the samples. However, analysis of individual viruses, known to infect honey bee, indicated that viral prevalence and viral loads of specific viruses is quite different among individual honey bees from the same colony. Interestingly we were able to find highly diverse Lake Sinai viruses. We were able to observe correlations either between individual viruses or viral other non-viral pathogens. Further analysis is...
Bartonella spp. Infection in Edible Dormice and Their Fleas
Klimešová, Běla ; Votýpka, Jan (advisor) ; Balážová, Alena (referee)
Bartonellosis is a group of emerging infectious diseases caused by facultatively intraerythrocytic bacteria transmitted between vertebrate hosts by arthropod vectors. Although only some Bartonella spp. are traditionally associated with human diseases, it was proposed that virtually any species can have zoonotic potential. The highest diversity of species was described from rodents acting as reservoirs with variable prevalence reaching up to 90%. Fleas associated with mammalian hosts play an important role in the Bartonella sp. lifecycle and are described to act not only as competent vectors but also as reservoirs for several species. The role of edible dormice (Glis glis), which often interacts with humans, and their fleas in the bartonellae transmission and lifecycle has so far been unknown; therefore, the prevalence and diversity of Bartonella spp. in edible dormice in the Czech Republic were studied. Complementary PCR analysis of four loci (gltA, rpoB, ftsZ, ITS), MALDI- TOF, and cultivation was performed to identify Bartonella sp. infections. The prevalence reaching 90% was found in dormice and their fleas. Altogether, four species were found and several genotypes of B. grahamii-like and yet undescribed Bartonella sp. were cultivated, and their morphology and growth requirements were...
Population Genetics of Parasites and Their Arthropod Hosts
Bezányiová, Kateřina ; Straka, Jakub (advisor) ; Votýpka, Jan (referee)
Arthropoda are currently the largest metazoan phylum. Given that organisms with parasitic lifestyle are thought to comprise the majority of existing species, it's easy to imagine an immense diversity of parasites interacts with arthropods. However, in comparison to organisms parasitising vertebrates, parasites of arthropods are direly understudied despite their abundance, importance, and potential usefulness. Amongst other things, parasites can be used as tools allowing the inference of information on host life history, ecology, and past events the host species have experienced. Population genetic structure of parasites and other symbionts may reflect these traits and events due to their close relationship with the host. Even though parasites comprise a diverse assemblage of taxa, it's possible to identify convergent patterns in their biology. Models predicting congruent population genetic co- structuring can be thus based on a few traits such as host specificity, life cycle complexity or parasite and/or host dispersal. In some cases, the parasite may provide better resolution of population structure than the host itself, serving as a proxy that may be used to direct conservation programmes of both the host and parasite, as has already been done with parasites of vertebrates. This thesis summarises known...
Honeybee parasites and their influence on the gut microbiome.
Řezníková, Johanka ; Tachezy, Jan (advisor) ; Votýpka, Jan (referee)
Given the great ecological and economic importance of the honeybee, the health of honeybee colonies is under intense research. The scientific community is desperately trying to understand the heavy losses in the honeybee population, which we are currently facing. The reduction in their population could be caused by insecticides, weather, diet composition, disruption gut microbiome, some bacteria, viruses, and parasites. A lot of information is known about individual stress factors, less so about the interaction between them. This work is therefore focused on summarising information about a few chosen honeybee parasites with consideration for their effect on the microbiome of the digestive tract. There were chosen six of the most important and commonly discussed species of parasites: Nosema apis and Nosema ceranae, Crithidia mellificae and Lotmaria passim, Varroa destructor, and Acarapis woodi. The first chapter is dedicated to the honeybee, its taxonomy, anatomy, life in the colony, and defense against pathogens. The second chapter discusses more details of the intestinal microbiome of bees, its composition, function, and disturbance. The following sections focus on individual bee parasites and their effect on the host's intestinal microbiome.

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