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Endo and Ectoparasites in working dogs
SRNCOVÁ, Štěpánka
The incidence of endo- and ectoparasites of dogs (especially working dogs) was observed in České Budějovice city and its surroundings. Dog faecal samples were collected for examination during December 2013 January 2015. The individual dogs were also checked for any other endo- and ectoparasites. The total of 176 individuals was examined. Of these, 27 were working dogs, 23 were dogs from shelters and 126 dogs were pets. Parasites were found in 33 dogs. Among positives, 27 individuals was infected with ectoparasites (5,68 % Ixodes ricinus, 1,7 % Otodectes cynotis, 0,57 % Cheyletiella yasguri and 6,82 % Ctenophalides ssp.) and 7 with endoparasites (2,27 % Toxocara canis, 0,57 % Trichuris vulpis and 1,14 % Dipylidium caninum).
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Factors regulating the expression and activity of digestive enzymes in the tick \kur{Ixodes ricinus}
KONVIČKOVÁ, Jitka
The intracellular proteolysis of ingested meal plays an essential role in tick development. The thesis focuses on the factors influencing the expressions and activities of digestive enzymes in Ixodes ricinus females during the feeding and post-feeding period. We have revealed the effect of fertilization on blood feeding and digestion. The females cannot reach the rapid engorgement phase without being fertilized. The rate of mated females in the nature proved the presumption that mating can occur even off the host. Implementation of in vitro feeding technique further extended our current knowledge about tick digestive apparatus. Adult females were fed on hemoglobin-rich and hemoglobin-poor diet and the mRNA expression levels of digestive proteases were determined. In line with obtained data, we assumed that albuminolysis is conducted by the same or similar pathway as hemoglobinolysis. The gene silencing method and protein immuno-detection were used to unequivocally identify the isoforms of 'early expressed' IrCL1 and 'late expressed' IrCL3 isoform of cathepsin L.
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Influence of dietary components and redox enzymes on intestinal microbiota proliferation in the tick \kur{Ixodes ricinus}
KUČERA, Matěj
In this work, we have analysed the temporal dynamics of gut-dwelling bacteria and Borrelia in the gut of the deer tick Ixodes ricinus. Using quantitative PCR, we have shown that levels of the tick intestinal microflora are profoundly decreased at later stages of feeding on whole blood but not on serum. Even though we noted that host complement system manages to interfere with Borrelia viability in vitro, we did not see any effect of host complement on Borrelia acquisition in adult ticks in vivo. However, we revealed that host hemoglobin is essential for Borrelia proliferation in the tick gut. All together, these data imply that, during feeding, levels of gut-dwelling bacteria and Borrelia are determined by the host. While hemoglobin seems to be detrimental for gut-dwelling bacteria, Borrelia require it in order to proliferate. During off-host stage, we showed that levels of gut-dwelling microflora are regulated by an intestinal transmembrane enzyme Dual oxidase. In conclusion, we aimed, and mostly succeeded, to perform pilot experiments describing the biology of a complex process of regulating gut microflora in the vector Ixodes ricinus and extend it by its impact on Borrelia acquisition
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Characterization and function of Factor C from the tick \kur{Ixodes ricinus}
HARTMANN, David
Factor C is a multi-domain serine protease which recognizes Gram-negative bacteria via binding to lipopolysaccharides and triggers hemolymph clotting cascade in the horseshoe crab. A closely related molecule was also found to be present in the genome of the tick Ixodes scapularis. In this work, the full sequence of Factor C ortholog from Ixodes ricinus (IrFC) was determined. IrFC is mainly expressed in tick hemocytes and the heavy chain of the activated molecules is present in tick hemolymph as confirmed by Western blotting with antibodies raised against recombinant fragments of IrFC. The function of the IrFC in tick innate immunity was assessed using its silencing by RNA interference.
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Localization of Lyme disease spirochetes \kur{Borrelia burgdorferi} in ticks \kur{Ixodes ricinus}
STRNAD, Martin
Lyme disease is the most common vector-borne infection in the Western world with an annual incidence usually in excess of 100 cases per 100 000 people in temperate areas of the United States and Europe. Same as other infectious diseases, Lyme borreliosis wreaks havoc on the host they have invaded. B. burgdorferi, the causative agent of this disease, circulates among wildlife vertebrate hosts and Ixodes tick vectors but may sometimes infect humans. Its natural enzootic cycle usually occurs as follows: The larval/nymphal stage tick feeds on an infected host. During this engorgement, the spirochetes reach the tick gut and stay confined to it. After the tick molts into the next developmental stage, it finds a second host. The new bloodmeal triggers the spirochetes to multiply within the gut and traverse the gut endothelium in a highly organized manner. They finally disseminate through the hemocoel up to the tick salivary glands and into the new host. We studied whether B. burgdorferi is capable of reaching the tick salivary glands during the first infective feeding period in uninfected ticks.
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Molecular characterization of NADPH oxidase in the gut of the tick \kur{Ixodes ricinus}
KUČERA, Matěj
This thesis focuses on characterization of one member of NADPH oxidases - dual oxidase (DUOX) which has been described as the main factor of epithelial immunity in the gut of model organism Drosophila melanogaster. We have identified an orthologous gene coding for DUOX in the tick I. ricinus and described its tissue expression profile. The DUOX is mainly expressed in the gut of unfed ticks and seems to be downregulated upon artificial microbial infection. A fragment of tick DUOX was prepared as recombinant protein and used for preparation of specific antibodies to be used for further characterization of the enzyme. Our main aim is to highlight the importance of tick DUOX producing the reactive oxygen species and their role in the defence against pathogenic organisms within the tick gut.
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