Ixodes scapularis is a primary vector of several important tick-borne pathogens including Borrelia burgdorferi sensu lato, the causative bacterial genospecies complex of Lyme disease, Babesia microti, Anaplasma phagocytophilum, Borrelia miyamotoi, Ehrlichia muris eauclarensis, and Powassan virus. Salivary compounds secreted by I. scapularis during blood feeding are immunogenic and can elicit robust antibody responses in humans which can potentially be leveraged as surrogate markers of prior tick bite exposure. In this study, we investigate the potential of a tick secreted salivary serine protease inhibitor, IxsS7, as a novel antigenic biomarker of I. scapularis exposure in humans. We demonstrate that the IxsS7 protein-coding sequence is highly conserved (>90 % identity) among other important Ixodes species (e.g., Ixodes ricinus, Ixodes persulcatus, and Ixodes pacificus) and poorly conserved (<50 % identity) with homologs from other tick genera, such as Amblyomma spp., Dermacentor spp., Rhipicephalus spp., and Haemaphysalis spp. Antibodies in sera from rabbits immunized with recombinant IxsS7 (rIxsS7) strongly recognize native IxsS7 when challenged with salivary gland homogenate (SGH) from blood-fed I. scapularis females, while showing minimal cross-reactivity with SGH from other hard tick (Ixodidae) genera. Western blot and ELISA analyses revealed that human subjects who reported recent prior exposure to ticks possessed IgG antibodies that recognized rIxsS7, highlighting its potential as a biomarker of exposure specifically against I. scapularis. Further development of serological tools that can measure human antibody responses to Ixodes-specific salivary antigens is essential to better quantify individual- and population-level risk of important tick-borne diseases such as Lyme disease.

• Klíčová slova
• Borrelia, Ixodes, Ixodid, Lyme, Tick, Tick saliva, Vaccine,
• Publikační typ
• časopisecké články MeSH

We prepared a digital questionnaire to capture knowledge, attitudes and practices (KAP) regarding ticks and tick-borne pathogens (TBPs) in 20 languages. The questionnaire was distributed to 21 universities and research institutions in 22 European countries and 9401 valid responses were collected. Most survey participants identified ticks correctly and regarded ticks as a serious health risk. There was also a good level of knowledge regarding tick activity, habitats and the predominant TBPs in the country or region. Moreover, most respondents were familiar with effective tick protection and removal measures. Over 75 % of respondents had been bitten by ticks and up to 12 % of participants had been diagnosed with a tick-borne infection in the past. Respondents from northern and central European countries who reported engaging in outdoor activities more frequently, reported increased frequencies of tick bites and infection with TBPs compared to respondents from southern Europe. Awareness of national information campaigns on ticks and TBPs was also greater among respondents from northern and central European countries than among Mediterranean countries. This study identified knowledge gaps among respondents from some European countries where TBPs have not been prioritised historically. These knowledge gaps should be addressed by reputable bodies to encourage personal protective behaviours without causing alarm and to forestall the spreading of incorrect and unreliable information propagated by some social media sources.

• Klíčová slova
• Europe, Ixodid ticks, Knowledge, attitudes and practices (KAP), Questionnaire survey, Tick-borne pathogens,
• Publikační typ
• časopisecké články MeSH

Ticks rely on host blood as their primary source of nutrients and energy. In hard ticks (Ixodidae), a single blood meal per life stage supports survival, metamorphosis, and, in females, egg production. The midgut, the major metabolic organ, is responsible for both digestion and nutrient storage. While previous studies have described tick midgut histology, many foundational works, often decades old, lacked modern histochemical, immunohistochemical, and high-resolution imaging techniques. Moreover, inconsistent nomenclature of midgut cells across species complicates comparative analyses. We herein chronologically examined structural changes in Ixodes ricinus nymphal midgut tissue before, during, and after feeding. Using immunofluorescence and immunoelectron microscopy, we monitored lipid droplet dynamics and the uptake of blood-derived proteins, including hemoglobin and serum albumin. To further investigate endocytic processes, we employed serial block-face scanning electron microscopy and TEM tomography, focusing on midgut samples from nymphs fed for 48 h. These approaches allowed us to visualize in 3D hemoglobin and albumin uptake from the gut lumen and their intracellular distribution within the nymphal caecum and midgut cells. Our findings enhance the understanding of tick gut cell biology, particularly nutrient processing and energy metabolism, providing a foundation for future research on tick physiology and vector competence.

• Klíčová slova
• Hemoglobin, Ixodes ricinus, Lipid droplets, Microscopy, Nymphal midgut, Tick feeding,
• Publikační typ
• časopisecké články MeSH

Ticks are important vectors of various microorganisms, including bacteria. In this study, we examined Hyalomma aegyptium ticks collected from 240 spur-thighed tortoises Testudo graeca at 42 localities in the Mediterranean and Middle East and analysed them for the presence of bacteria of the genera Anaplasma, Borrelia, Coxiella, and Rickettsia. Altogether, 576 out of 928 analysed ticks (62.1%) were positive for at least one of the tested bacteria. The highest prevalence in individual ticks was found for Borrelia turcica (43.6%), followed by Rickettsia (12.3%) and Anaplasma (6.1%). No sample was positive for Coxiella burnetii. Among Rickettsia, we detected two species, Rickettsia africae and Rickettsia aeschlimannii, and also other unspecified Rickettsia. Anaplasma (100% identity with A. phagocytophilum) was detected at 15 (35%) out of 42 studied localities, any of Rickettsia at 28 (67%), and B. turcica at 32 (76%) localities. The geographic distribution of the studied microorganisms varied, with none of them detected in Syria, and only Rickettsia spp. detected in Morocco. Sequence analysis revealed substantial genetic variability in all detected agents, with the most variable (36 new haplotypes) being glpQ gene used as a marker for B. turcica. We also analysed the prevalence of various co-infections among studied ticks, with the mean number of co-infected ticks per tortoise increased with the number of ticks per tortoise. However, the frequencies of co-infected ticks do not indicate the presence of antagonistic or synergistic facilitative interactions between the agents. According to our data, we could expect that the eco-epidemiological importance of H. aegyptium does not stem from their tortoise hosts but rather from the low host specificity of its larvae and nymphs, feeding on a wider spectrum of reptilian, avian, and mammalian hosts.

• Klíčová slova
• Anaplasma, Borrelia turcica, Co-infections, Coxiella burnetii, Hyalomma aegyptium, Rickettsia,
• MeSH
• Anaplasma izolace a purifikace   genetika   MeSH
• Borrelia izolace a purifikace   genetika   MeSH
• Coxiella izolace a purifikace   genetika   MeSH
• infestace klíšťaty veterinární   parazitologie   epidemiologie   MeSH
• Ixodidae * mikrobiologie   MeSH
• Rickettsia * izolace a purifikace   genetika   MeSH
• želvy * parazitologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Střední východ epidemiologie   MeSH
• Středomoří epidemiologie   MeSH

Categorization systems for tick-borne encephalitis virus (TBEV) infection lack consistency in classifying disease severity. To evaluate the need for a standard, consensus-based categorisation system for TBEV infection across subtypes, we gathered an expert panel of clinicians and scientists with diverse expertise in TBEV infection. Consensus was sought using the Delphi technique, which consisted of 2 web-based survey questionnaires and a final, virtual, consensus-building exercise. Ten panellists representing 8 European countries participated in the Delphi exercise, with specialities in neurology, infectious disease, paediatrics, immunology, virology, and epidemiology. Panellists reached unanimous consensus on the need for a standardised, international categorisation system to capture both clinical presentation and severity of TBEV infection. Ideally, such a system should be feasible for use at bedside, be clear and easy to understand, and capture both the acute and follow-up phases of TBEV infection. Areas requiring further discussion were (1) the timepoints at which assessments should be made and (2) whether there should be a separate system for children. This Delphi panel study found that a critical gap persists in the absence of a feasible and practical classification system for TBEV infection. Specifically, the findings of our Delphi exercise highlight the need for the development of a user-friendly classification system that captures the acute and follow-up (i.e., outcome) phases of TBEV infection and optimally reflects both clinical presentation and severity. Development of a clinical categorisation system will enhance patient care and foster comparability among studies, thereby supporting treatment development, refining vaccine strategies, and fortifying public health surveillance.

• Klíčová slova
• Categorisation, Delphi panel, Disease severity, Tick-borne encephalitis,
• MeSH
• delfská metoda MeSH
• klíšťová encefalitida * klasifikace   virologie   diagnóza   patologie   MeSH
• konsensus MeSH
• lidé MeSH
• viry klíšťové encefalitidy * fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH

The emergence of tick-borne encephalitis (TBE) in Europe marked several significant milestones. The discovery of TBE in Czechoslovakia in 1948, with Gallia and Krejčí simultaneously isolating the TBE virus (TBEV) from human samples for the first time in Europe outside the Soviet Union, was pivotal. Subsequent TBEV isolation from ticks suggested the viral transmission via this vector. In 1951, the outbreak in Rožňava in Slovakia (Czechoslovakia) revealed an unexpected mode of transmission, unpasteurized milk from a local dairy, challenging existing understanding. Investigations exposed illicit practices of mixing cow's milk with goat's milk for economic gains. Laboratory research confirmed the outbreak was caused by TBEV, which was substantiated by serological analyses. This was the first and largest documented alimentary TBE outbreak in history. In this review, we delve into both published sources and unpublished archival data, offering a comprehensive understanding of these historic accomplishments and shedding light on these pivotal moments.

• Klíčová slova
• Alimentary infection, History, Tick-borne encephalitis, Tick-borne encephalitis virus, Virus discovery,
• MeSH
• epidemický výskyt choroby MeSH
• klíšťová encefalitida * MeSH
• lidé MeSH
• skot MeSH
• viry klíšťové encefalitidy * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH
• SSSR MeSH

Tick-borne encephalitis (TBE) and Lyme neuroborreliosis (LNB), the most common tick-borne diseases of the central nervous system in Central Europe, are frequently associated with pareses. The aim of this study was to characterise paretic complications in patients with TBE and LNB, including their severity, persistence and impact on the patients' quality of life. Our retrospective observational study included patients with aseptic CNS infection due to TBE virus or Borrelia burgdorferi sensu lato. Paretic complications were evaluated in the acute phase and the patients were followed up until complete regression or long-term stabilisation of any neurological deficit. The severity of the neurological deficit was graded according to the modified Rankin Scale (mRS). A total of 823 patients (582 with TBE, 241 with LNB) was included. Paretic complications were diagnosed in 63 TBE patients (10.8 %) and in 147 LNB patients (61.0 %). In TBE, the most common neurological deficit was brachial plexus paresis in 21 patients (33 %) and bulbar symptoms in 18 patients (29 %). In LNB patients, facial nerve palsy was the most frequent neurological deficit (117patients; 79.6 %), followed by lower limb paresis in 23 patients (15.6 %). Forty-nine TBE patients and 134 LNB paretic patients completed follow-up. Paresis resolved within 3 weeks in 16 TBE patients (33 %) and 53 LNB patients (39.5 %), but the proportion of patients with paresis persisting for more than 12 months was significantly higher in TBE (34.7 vs. 3.7 %, p < 0.001). The mean mRS was significantly higher in TBE paretic patients compared to LNB (p < 0.001). Paretic complications are significantly more common in LNB than in TBE but pareses associated with TBE last longer than in LNB and considerably reduce the quality of life of patients. Prevention remains the only way to influence the long-term motor deficits of TBE.

• Klíčová slova
• Long-term deficit, Lyme neuroborreliosis, Paresis, Tick-borne encephalitis,
• MeSH
• klíšťová encefalitida * komplikace   epidemiologie   diagnóza   MeSH
• kvalita života MeSH
• lidé MeSH
• lymská neuroborelióza * komplikace   epidemiologie   diagnóza   MeSH
• paréza etiologie   komplikace   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

Viral infection may represent a stress condition to the host cell. Cells react to it by triggering the defence programme to restore homeostasis and these events may in turn impact the viral replication. The knowledge about tick-borne encephalitis virus (TBEV) infection-associated stress is limited. Here we investigated the interplay between TBEV infection and stress pathways in PMJ2-R mouse macrophage cell line, as macrophages are the target cells in early phases of TBEV infection. First, to determine how stress influences TBEV replication, the effect of stress inducers H2O2 and tunicamycin (TM) was tested. Viral multiplication was decreased in the presence of both stress inducers suggesting that the stress and cellular stress responses restrict the virus replication. Second, we investigated the induction of oxidative stress and endoplasmic reticulum (ER) stress upon TBEV infection. The level of oxidative stress was interrogated by measuring the reactive oxygen species (ROS). ROS were intermittently increased in infected cells at 12 hpi and at 72 hpi. As mitochondrial dysfunction may result in increased ROS level, we evaluated the mitochondrial homeostasis by measuring the mitochondrial membrane potential (MMP) and found that TBEV infection induced the hyperpolarization of MMP. Moreover, a transient increase of gene expression of stress-induced antioxidative enzymes, like p62, Gclm and Hmox1, was detected. Next, we evaluated the ER stress upon TBEV infection by analysing unfolded protein responses (UPR). We found that infection induced gene expression of two general sensors BiP and CHOP and activated the IRE1 pathway of UPR. Finally, since the natural transmission route of TBEV from its tick vector to the host is mediated via tick saliva, the impact of tick saliva from Ixodes ricinus on stress pathways in TBEV-infected cells was tested. We observed only marginal potentiation of UPR pathway. In conclusion, we found that TBEV infection of PMJ2-R cells elicits the changes in redox balance and triggers cellular stress defences, including antioxidant responses and the IRE1 pathway of UPR. Importantly, our results revealed the negative effect of stress-evoked events on TBEV replication and only marginal impact of tick saliva on stress cellular pathways.

• Klíčová slova
• Cellular stress, Flavivirus, Mitochondrial homeostasis, Oxidative stress, Stress on endoplasmic reticulum, Tick saliva, Tick-borne encephalitis virus, Unfolded protein response, Virus replication,
• MeSH
• buněčné linie MeSH
• klíšťová encefalitida * MeSH
• myši MeSH
• peroxid vodíku metabolismus   MeSH
• protein-serin-threoninkinasy metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• replikace viru MeSH
• viry klíšťové encefalitidy * genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• peroxid vodíku MeSH
• protein-serin-threoninkinasy MeSH
• reaktivní formy kyslíku MeSH

Genomes of ticks display reductions, to various extents, in genetic coding for enzymes of the haem biosynthetic pathway. Here, we mined available transcriptomes of soft tick species and identified transcripts encoding only half of the enzymes involved in haem biosynthesis. Transcripts identified across most species examined were those coding for porphobilinogen synthase, coproporphyrinogen oxidase, protoporphyrinogen oxidase, and ferrochelatase. Genomic retention of porphobilinogen synthase seems to be soft tick-restricted as no such homologue has been identified in any hard tick species. Bioinformatic mining is thus strongly indicative of the lack of biochemical capacity for de novo haem biosynthesis, suggesting a requirement for dietary haem. In the hard tick Ixodes ricinus, depletion of dietary haem, i.e. serum feeding, leads to oviposition of haem-free eggs, with no apparent embryogenesis and larvae formation. In this work, we show that serum-fed Ornithodoros moubata females, unlike those of I. ricinus, laid haem-containing eggs similarly to blood-fed controls, but only by a small proportion of the serum-fed females. To enhance the effect of dietary haem depletion, O. moubata ticks were serum-fed consecutively as last nymphal instars and females. These females laid eggs with profoundly reduced haem deposits, confirming the host origin of the haem. These data confirm the ability of soft ticks to take up and allocate host haem to their eggs in order to drive reproduction of the ticks.

• Klíčová slova
• Haem biosynthesis, Membrane feeding, Ornithodoros, Parasitism, Porphobilinogen synthase, Soft ticks,
• MeSH
• Argasidae * MeSH
• hem MeSH
• Ixodidae * MeSH
• Ornithodoros * MeSH
• Ornithogalum MeSH
• porfobilinogensynthasa MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hem MeSH
• porfobilinogensynthasa MeSH

The red fox (Vulpes vulpes) is the most widespread free-living carnivore in the world. Over the years, foxes have been recognized as hosts for a number of tick-borne pathogens. However, their role as reservoirs for zoonotic tick-borne diseases is poorly understood. The aim of our study was to investigate tick-borne pathogens in the red fox population in the Czech Republic. Out of 117 red foxes, 110 (94.02%) individuals tested positive for the presence of at least one pathogen by the combined PCR and sequencing approach. Hepatozoon canis was the most frequently detected pathogen (n = 95; 81.2%), followed by Babesia vulpes (n = 75; 64.1%). Babesia canis was not detected in our study. Four (3.42%) red foxes were positive for Candidatus Neoehrlichia sp., 3 (2.56%) for Anaplasma phagocytophilum, and one red fox (0.85%) tested positive for the presence of Ehrlichia sp. DNA. Overall, DNA of spirochetes from the Borrelia burgdorferi s.l. complex was detected in 8.6% of the foxes and B. miyamotoi in 5.12% of the samples. As a carnivore found in all ecosystems of Central Europe, foxes obviously contribute to transmission of tick-borne pathogens such as A. phagocytophilum, B. burgdorferi s.l., and B. myiamotoi. In addition, foxes apparently harbour a community of pathogens, associated with this host in local ecological context, dominated by H. canis and B. vulpes (possibly also Candidatus Neoehrlichia sp.). These species have the potential to spread to the domestic dog population and should be included in the differential diagnosis of febrile diseases with hematologic abnormalities in dogs.

• Klíčová slova
• Anaplasma, Babesia, Borrelia, Candidatus Neoehrlichia, Carnivores, Ehrlichia, Tick-borne pathogens, Vulpes vulpes,
• MeSH
• ekosystém MeSH
• klíšťata * MeSH
• lišky * MeSH
• psi MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Evropa MeSH