National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
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...
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.