National Repository of Grey Literature 23 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
The influence of microbiome to pesticide resistence of stored product mite Tyrophagus putrescentiae
Bostlová, Marie ; Hubert, Jan (advisor) ; Mourek, Jan (referee)
Model organism used in this study is stored product mite specifically Tyrophagus putrescentiae. Presence of microorganisms may cause physiological changes (especially changes of immune system) which can result in different pesticide tolerance of tested mite population. The most effective way how to control mite is by acaricide application. We compare the reaction of two T. putrescentiae populations to pesticide treatment. The mite population differ in symbiont composition: symbiotic population 5P containing Wolbachia and asymbiotic population 5Pi with absence of Wolbachia. We observe negative effect of all tested treatments to mite reproduction rate. We used filter paper tests, growing tests and microbiome analyzes. High concentrations of pesticides in the diet reduced the presence of Wolbachia, Bartonella, and Bacillus bacteria in the 5P symbiotic population. This phenomenon was less noticeable in the asymbiotic population. Medium concentration of deltamethrin and primifos methyl increased diversity in the symbiotic population but not in asymbiotic one. The results showed that the asymbiotic population did not have a significantly different tolerance to pesticides compared to the asymbiotic population. However, they showed that the presence of pesticides in the diet affects the composition of the...
The effect of abiotic factors on house dust mites Dermatophagoides farinae
Vacková, Tereza ; Hubert, Jan (advisor) ; Zemek, Rostislav (referee)
House dust mites are one of the most important allergenic agents found in households worldwide. The biology of these mites is significantly affected by hygrothermal factors - especially by temperature and humidity. The study is focused on the influence of temperature and humidity to the behavior of Dermatophagoides farinae within a thermal gradient (simulating a vertical section of a mattress), on its metabolism (represented by respiration rate) and population growth. Within a constant thermal gradient (19-41 řC) run for 24 h D. farinae mites most often received food in the sector with a temperature range of 32-36 řC. In experiment with 5 days of alternating cycles of the same gradient (8 h / day) and room temperature (16 h / day) was the sector with a temperature range of 32-36 řC for mite's feeding also the most prefered. In contrast, in both variants of the experiment, non-feeding mites preferred the sector with a temperature range of 19-23 řC (or rather, the largest number of them were found in this sector during the evaluation). During the measurement of respiration, mites of this species showed significant CO2 production when were incubated at temperatures of 25- 30 řC. Out of the studied combinations of temperature and humidity, the highest respiration was measured when mites were incubated...
The effect of constant temperature and moisture to house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae
Gajdová, Tereza ; Hubert, Jan (advisor) ; Žůrek, Luděk (referee)
House dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae inhabit house dust worldwide. These commensals are for humans harmful especially as producers of many allergens. According to Klimov-OConnor's hypothesis, these mites had a parasitic ancestor who had evolved into a free-living form during the evolution. This thesis focuses on another possible aspect of this transition: it compares optimal hygrothermal conditions for development, reproduction, and population growth of Dermatophagoides dust mites with those which are preferred by the house dust mite's related - parasitic genera Sarcoptes and Psoroptes. Since all these three genera are closely related, it was analyzed whether their hygrothermal preferences would be similar in any respect. However, the results of this literature review suggest that dust mites - compared to their parasitic relatives - prefer combinations of lower temperatures and humidity. Like the representatives of the convergent group of storage mites - e. g. Tyrophagus putrescentiae and Acarus siro. Apart from the comparison of the preferred conditions of previously mentioned genera, this thesis also presents a summary of the effect of different combinations of temperatures and humidity on the duration of development, fecundity, and the population growth of...
Paenibacillus larave destroying the honeybees (Apis mellifera) population
Haltufová, Kristýna ; Hubert, Jan (advisor) ; Kamler, Martin (referee)
Paenibacillus larvae is Gram-positive, spore-forming, rod-shaped bacteria. This pathogen threatens one of the most considerable worldwide pollinators - the honeybee (Apis mellifera). It is causative agent of bee disease called American foulbrood. Although it affects only bee larvae, preferably on the first day of its live, it is highly contagious and could quickly destroy whole bee colony. Adult bees are not susceptible to infection, however due to huge spores resilient of P. larvae, they perform the role of main disease vector. Also the careless beekeepers make it easier to spread. Bee diseases are enquired by state veterinary administration, because honeybee is classified as a livestock. If disease evolves to clinic phase, infected bees and hive with all tools must be burned. American foulbrood is one of the most deleterious bee diseases. This bachelor thesis discuss about problems of whole disease and it is focused on the interactions between bacteria Paenibacillus larvae, hymenoptera insect honeybee and human factor presented by beekeepers, state veterinary administration and corresponding laws. Key words: Paenibacillus larvae, American Foulbrood, entomopathogenic bacteria, Apis mellifera, honeybee
Can symbiotic bacteria of storage mite Acarus siro alter its response to biocides?
Navrátilová, Blanka ; Hubert, Jan (advisor) ; Mourek, Jan (referee)
Storage mite Acarus siro is one of the most distributed stored product mites in the world. It infests various products (grains, dried fruits, meat products, animal feed etc.) and causes allergic reactions in humans. For these reasons, it is important to find an effective strategy to suppress or even better to eliminate the mite from the storing facilities. Historically, there have been reported cases of the mite being resistant to several pesticides. In this thesis, four populations of Acarus siro were exposed to pesticides in different concentrations - first in the form of solutions and next as a diet additive. The populations showed divergent sensitivity to four selected pesticides (pirimiphos-methyl, chlorpyriphos-methyl, deltamethrin and deltamethrin in combination with piperonyl butoxide). The biggest differences were recorded in response to solutions of pirimiphos-methyl. This pesticide was then added to standard rearing diet in five concentrations. The mite populations were exposed to this died for 3 weeks. Control and pesticide-treated diet microbiome analyses revealed that 0.0125 µg×g-1 concentration causes hormoligosis in 6L and 6Tu strains. The same concentration was responsible for microbiome change in 6Z strain. Exposure to 1,25 µg×g-1 concentration caused microbial shifts in 6Z and...
Honey bee (Apis mellifera) workers as transmitters and reservoirs of American foulbrood (Paenibacillus larvae)
Haltufová, Kristýna ; Hubert, Jan (advisor) ; Kamler, Martin (referee)
Paenibacillus larvae is a gram-positive spore-forming bacterium that affects and kills the larvae of the honey bee (Apis mellifera) and causes the American foulbrood disease. Adults bees do not become infected, but they transmit tenacious spores within the hive and between hives and can infect larvae while caring for them. It is not allowed by law to treat bees in the Czech Republic, but the recommended preventive method for reducing the amount of spores in the hive is the shook swarm method (bees are moved to a new clean hive and the old hive is destroyed with all brood and supplies). The aim of this work was to detect and quantify P. larvae in bee workers using the quantitative real-time polymerase chain reaction (qPCR). In the first experiment, the two set of samples were taken - bees before and after the shook swarm method, but the expected decrease in spores in the samples taken after shook swarm was not confirmed, and conversely, non-specific products were amplified. In the second experiment, the presence of P. larvae spores in samples from heavily infected hives (with clinical symptoms of American foulbrood) and from hives with almost no findings of P. larvae spores, both originating from the same habitat, were compared. In this case, the differences were clearly visible. There were not...
The effect of constant temperature and moisture to house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae
Gajdová, Tereza ; Hubert, Jan (advisor) ; Žůrek, Luděk (referee)
House dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae inhabit house dust worldwide. These commensals are for humans harmful especially as producers of many allergens. According to Klimov-OConnor's hypothesis, these mites had a parasitic ancestor who had evolved into a free-living form during the evolution. This thesis focuses on another possible aspect of this transition: it compares optimal hygrothermal conditions for development, reproduction, and population growth of Dermatophagoides dust mites with those which are preferred by the house dust mite's related - parasitic genera Sarcoptes and Psoroptes. Since all these three genera are closely related, it was analyzed whether their hygrothermal preferences would be similar in any respect. However, the results of this literature review suggest that dust mites - compared to their parasitic relatives - prefer combinations of lower temperatures and humidity. Like the representatives of the convergent group of storage mites - e. g. Tyrophagus putrescentiae and Acarus siro. Apart from the comparison of the preferred conditions of previously mentioned genera, this thesis also presents a summary of the effect of different combinations of temperatures and humidity on the duration of development, fecundity, and the population growth of...
Microbial association with house dust mites
Molva, Vít ; Hubert, Jan (advisor) ; Žůrek, Luděk (referee)
The house dust mites (HDM; Dermatophagoides farinae and Dermatophagoides pteronyssinus) obtain nutrients from the debris of the skin, hairs and nails, that get off the human and animal body. These debris are covered by microorganisms and the microorganisms are the key factor in the survival of HDM in human-made environments. In this study we made manipulative experiments with the extract from spent growth medium (SPGM). SPGM is the medium after mite cultivation, composed from mite feces, debris of the diet, dead mite bodies and microorganisms. The extract from SPGM (one and three-month-old mite cultures) was used as the source of microorganism to transfer them into diet of D. farinae a D. pteronyssinus. The composition of the bacterial and fungal microbiomes differed between the HDM species, but the SPGM extract addition into diet influenced only the bacterial profile of D. farinae. In the D. farinae microbiome of specimens on SPGM-treated diets compared to those of the control situation, the Lactobacillus spp. profile decreased, while the Cardinium, Staphylococcus, Acinetobacter, and Sphingomonas profiles increased. The addition of SPGM extract decreased the microbial respiration in the microcosms with and without mites in almost all cases. Adding SPGM did not influence the population growth of D. farinae,...
Melissococcus plutonius causing European foulbrood
Navrátilová, Blanka ; Hubert, Jan (advisor) ; Titěra, Dalibor (referee)
European foulbrood is a bacterial disease attacking honey bee larvae worldwide. It is caused by bacterium Melissococcus plutonius, which is a non-spore-forming, Gram positive, anaerobic bacterium. The adult bees are not affected but serve as a vector of the disease as they carry the bacterium within their own bodies and can travel big distances from their hive and also may interact with other hives especially when their own colony is suffering. Once the bacterium is introduced into the colony, it either remains benign and unnoticed for years, keeping its population low, or it can multiply vigorously within the brood and destroy the entire bee populations. Despite having been described many decades ago, M. plutonius as such along with its virulence remain poorly understood and therefore there is no treatment efficient enough that would keep this bacterium along with the disease under control. Hence it is of a great importance to recognize its presence soon enough to prevent the outbreak. This thesis brings together the knowledge we have so far about this mysterious bacterium and sums up how European foulbrood is being treated all around the world.
Synanthropic arthropods as a producers of allergens in households
Smetanová, Ivana ; Hubert, Jan (advisor) ; Frouz, Jan (referee)
This work is about arthropods producing allergens in our homes. It sums together not just todays knowledge about allergic effects in human environment and possible diseases, but also about behavior, occurrence and life cycle of species themself and about possible elimination arthropods and allergens from our households. Most of the world population is nowadays affected by the allergies, allergens are all around us. In today's world when people spend most of the time in the interior enviroment whitch contains allergens and their sources, are also important allergic diseases caused by the arthropods, which we share our homes with. Almost in every room in our home are present some of the arthropods producing allergens. These allergens can affect the life of sensitive persons. Allergens are inside the body of the arthropods and in their body secretions. The highest volume of allergens coming from arthropods in our homes is contained in a dust and food. Allergic reaction is caused by consummation, inhalation or body contact. The cheapest and the most effective treatment of the allergic diseases is to avoid the allergens. The best what we can do is to regulate their volume in our households, because the complete elimination is practically impossible. Key words: Allergens, synanthropic arthropods, households

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