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The aim is to present the results of monitoring the activity of Ixodes ricinus ticks and their positivity for dangerous pathogenic microorganisms in the Brno-Pisarky forest park. The monitored pathogens were Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Coxiella burnetii, Erhlichia chaffensis and Francisella tularensis. Additionally, factors potentially influencing tick activity in the location (especially the temperature) were monitored.In the location, ticks were caught using the flagging method. Positivity of ticks was determined by polymerase chain reaction followed by gel electrophoresis.Between March and November 2021, 563 ticks were collected in the location, the vast majority being nymphs (85 %). The positivity rates were 5.6 % for the pathogen Bbsl was and 2.4 % for A. phagocytophilum. C. burnetii, E. chaffensis and F. tularensis were not confirmed in the location.The location was found to be infested with the pathogens Bbsl and A. phagocytophilum. However, the positivity in Brno-Pisarky is lower compared to other Brno areas.

Micro-computed tomography (micro-CT) is an exceptional non-destructive imaging modality, which can be used to visualize both external and internal morphology of arthropods like ticks. The major micro-CT drawback is the soft tissues visualization, which require pre-examination contrasting steps. The commonly employed tick contrasting methods are drying and immersion in a solution containing a high-atomic number element, which both cause major deformation and shrinkage of examined specimens. The aim of this study was to develop a new tick contrasting approach to bypass these limitations. We show that adult Ixodes ricinus females engorged in vitro on blood enriched with gold nanoparticles with polyethylene glycol coating can be scanned with excellent contrast. By utilizing this technique based on the hematophagous nature of the ticks, we were able to observe midgut lumen, midgut epithelium and rectal sac in their natural state. In addition, we were able to precisely calculate the midgut volume.

In 2005 and 2006, Ixodes ricinus ticks were collected on two slag (waste rock) heaps from coal mines in the Ostrava area (North Moravia/Silesia, Czech Republic), Oskar (site A) and Emma (site B), partially covered by vegetation including trees, and at a control forest site near Hlucín (site C). The mean numbers of L. ricinus nymphs and imagoes flagged per person-hour were high: 35.3 nymphs and 12.7 imagoes, at site A, 23.3 and 26.0, respectively, at site B, and 25.4 and 16.8, respectively, at control site C. Using dark-field microscopy, 100 nymphs and 100 imagoes (50 females and 50 males) from each site were examined for borreliae. The mean prevalence rates of Borrelia burgdorferi sensu lato in nymphs and imagoes were 10.0% and 12.0%, respectively, at site A, 10.0% and 24.0%, respectively, at site B, and 13.0% and 17.0%, respectively, at site C. Differences in the prevalence of borreliae in nymphal and adult ticks from the slag heaps and control site were insignificant, but adult ticks from site B compared to site A contained borreliae significantly more frequently. The mean numbers of nymphs and imagoes infected with borreliae flagged per person-hour were 3.3 and 1.2, respectively at site A, 1.5 and 2.9, respectively, at site B, and 3.1 and 2.6, respectively, at site C. Isolation experiments for borreliae were carried out only in 16 ticks containing higher numbers of borreliae, with eight of these being culture-positive. The cultured borreliae were identified by PCR-RFLP as B. garinii (3 isolates: two from site B, one from site C), B. afzelii (4 isolates: one from site A, three from site B) and B. burgdorferi s.s. (one isolate from site A). Surprisingly, the results suggest that slag heaps, when covered by woody vegetation and frequented by humans, could theoretically pose roughly the same LB transmission risk to humans as common forest biotopes.

6 1. Abstrakt Hyaluronidázy jsou významnou skupinou enzymů odpovědných za štěpení kyseliny hyaluronové, která je jednou z hlavních složek pojivové tkáně obratlovců. U většiny krevsajících členovců je tento enzym přítomen ve slinách a usnadňuje sání tím, že se podílí na průniku kůží a zvětšení potravní léze v místě bodnutí. Vzniklé fragmenty extracelulární matrix mohou navíc modulovat lokální imunitní odpověď hostitele a zvyšovat pravděpodobnost přenosu patogenů. V naší práci jsme se zaměřili na průkaz hyaluronidázové aktivity u klíštěte Ixodes ricinus (Acari: Ixodidae) a zástupců čtyř rodů ovádů (Diptera: Tabanidae). V slinných žlázách klíšťat se hyaluronidázovou aktivitu detekovat nepodařilo. Naopak, ve slinných žlázách ovádů jsme prokázali velmi silnou aktivitu u všech studovaných druhů a dále ji charakterizovali biochemickými a elektroforetickými metodami. Hyaluronidázy ovádů štěpí hyaluronan i chondroitin sulfát; enzymy jednotlivých druhů se mírně liší molekulovou hmotností, pH optimem a citlivostí k redukujícím podmínkám. Abstract (in English) Hyaluronidases are an important group of enzymes responsible for cleaving hyaluronic acid, which is a major component of the extracellular matrix of vertebrates. In bloodsucking arthropods these enzymes are frequently present in saliva. Salivary hyaluronidases...

In an investigation conducted in the South and West Bohemian region the author paid attention to the incidence of the tick Ixodes ricinus and foci of tick-borne encephalitis in original plant communities. In Southern Bohemia in places of original communities of acidophil oak forests, oak-hornbeam woods and their mosaic combinations as well as combinations of flowers and beech forests and meadows and alder trees the author detected 93.5% of the breeding places of ticks. In Western Bohemia in original oak forests there were 97.2% breeding places of Ixodes ricinus. In other original plant communities, although influenced and partly altered by human activities--i.e. in highly located beech woods and pine tree woods and in damp communities--in peatbogs, meadows and grassland no ticks were found. Evaluation of a territory, based on plant and animal communities and typical species as their indicators, is a useful method as regards the prognosis of the prevalence of ticks or possibly foci of tick-borne encephalitis, as was demonstrated on the example of an uncommon focus of tick-borne encephalitis and tick-borne borreliosis on the upper Vltava river.

The aim of the article is to present the results of monitoring the prevalence of the spirochete Borrelia burgdorferi sensu lato (Bbsl) in Ixodes ricinus ticks in two different locations in the city of Brno, Pisárky and Zamilovaný hájek (ZH). At the same time, factors potentially affecting the activity of ticks in these locations were studied. Results of the monitoring carried out in the first three spring months of the year 2011 are compared with 2010 results.In 2010-2011, Ixodes ricinus ticks were periodically sampled in two locations in Brno by flagging. Ticks were investigated by dark field microscopy (DFM) for the presence of spirochetes. DFM-positive samples from 2010 were tested by PCR to identify Bbsl.In the first three spring months (March-May) of 2011, a total of 234 ticks were collected in Pisárky and 211 ticks in ZH. Positive samples detected by DFM accounted for 5.56 % in Pisárky and 25.12 % in ZH. PCR confirmed Bbsl in at least 75 %. Statistical analysis confirmed the dependence of tick activity on the air temperature in both locations.Within the same city, seroprevalence was found to be different in two locations. High seroprevalence in ZH (25.12 %) could be attributed to focal spread of the disease from several sources, both ticks and reservoirs such as rodents. This may results in unfavourable epidemiological situation in Brno. On the other hand, the seroprevalence rates in Pisárky are consistent with findings from an earlier long-term study.

Antimicrobial (cationic) proteins play an important role in innate imunity. Such proteins can possess antibacterial, antiendotoxic or fungicidal abilities. The rising resistence of microbes to common antibiotics evokes acute need of studying more endogenous proteins to reveal new potential antibiotics. Ticks, the blood-feeding ectoparasites with effectual defense system, present an endless source of newly described and unknown antimicrobial peptides/proteins with significant theurapeutic potential. This study represents identification of histidine-rich proteins detected in Ixodes ricinus and Ixodes scapularis, that are related to recently described new family of proteins isolated from Rhipicephalus microplus (protein microplusin) and Amblyomma hebraeum (protein heraein). Analysis and characterization of newly identified histidine rich proteins, study of their antimicrobial and protease inhibitory effect are the main goals of this study.

A total of 369 Ixodes ricinus ticks (330 nymphs, 39 adults) were collected in the urban park area Stromovka in Ceske Budejovice (Czech Republic) and tested for the presence of Lyme disease spirochets Borrelia burgdorferi sensu lato

Recombinant cysteine peptidases of Ixodes ricinus Jindřich Srba Abstract Intracellular proteolysis of ingested blood proteins is a crucial physiological process in ticks. In a tick, Ixodes ricinus, cysteine proteases, cathepsins B and L, are part of a gut-associated multi-peptidase complex. This thesis deals with preparation of recombinant procathepsins B and L and characterization of functional and biochemical properties of cathepsins B and L. After expression procathepsins B and L in E. coli and their purification from inclusion bodies by affinity chromatography, the basic strategy was searched that would enable to achieve successful refolding. A suitable type in both cases showed to be "basic" refolding. Both refolded procathepsins were auto-activated in the acidic environment of pH 4,0; cathepsin B (but not cathepsin L) also at pH 5,5. Activity was determined at pH dependence substrate specificity and inhibition. The pH optimums for hydrolytic activity of cathepsins B and L were in the range of 4,5 - 5,5 and 3,0 - 3,5, respectively. Both enzymes were blocked by an inhibitor of cysteine peptidase group and each of them by specific inhibitors designed for mammalian cathepsins B and L. The results of this thesis show that cathepsins B and L produced in the gut I. ricinus exhibit exo- and endo-peptidase...

The proposed thesis brings new information on several aspects of tick glycobiology - tick N-glycans, tick lectins, and glycosylation of the tick-borne pathogen, Lyme disease spirochetes Borrelia burgdorferi s.l.

We examined by dark field microscopy 195 of 209 Ixodes ricinus ticks that were removed from humans in the Czech Republic (mainly in southern Moravia) during 1997-2001. The majority of the ticks were nymphs (62%), 31% were females and 7% larvae; 10.7% of the nymphs, 20.3% of the females but no larvae were found to be infected with B. burgdorferi s.l., the agent of Lyme borreliosis (LB). This observation supports for Central Europe the conclusions drawn from North America about nymphal ixodid ticks as the most important vector stage in transmission of LB. In the course of the year, we found the highest proportion of infected nymphal and female ticks taken off humans in June. The detection of borreliae in a human-biting tick is an important step that enables the general practitioner to prescribe prophylactic antimicrobial treatment and to reduce significantly the risk of Lyme disease in the patient.

Ticks are interesting ectoparasites for their ability to modulate the host's defense response. This ability of tick saliva is often exploited by pathogens to increase their transmission. Therefore many researchers focused on identification of molecules in tick saliva and their possible medical use. This thesis focuses on the high natural presence of anti-Gal antibodies in human serum and it's interaction with alpha-gal epitope that is expressed on the surface of some pathogens and mammalian cells. This epitope has been identified in tick saliva and some drugs as well.

Blood-feeding arthropods, Ixodes ricinus acquire and digest vast amounts of the host blood meal, which often exceeds their body volume up to 100 times. It seems to be an only source of energy which they need for the reproduction. I identified homologues of six sugar transporters genes encoding sugar transporters in the I. ricinus tick. Transcripts encoding sugar transporters were found in digestive tract of I. ricinus. The results of RT PCR analysis characterised tissue expression profiles of the sugar transporters while fed by blood. The sugar transporters were determined as a drug target by RNAi. In this master thesis, the use of RNAi and available sugar inhibitors did not confirm glucose importance in physiology of ticks. Membrane feeding showed that blood meal with 2-deoxy-D-glucose had a significant impact on the reproduction and viability of the ticks.