Aurora kinases (AURK) play a central role in controlling cell cycle in a wide range of organisms. They belong to the family of serine-threonine kinase proteins. Their role in the cell cycle includes, among others, the entry into mitosis, maturation of the centrosome and formation of the mitotic spindle. In mammals, 3 isoforms have been described: A, B and C, which are distinguished mainly by their function throughout the cell cycle. Two aurora kinase coding sequences have been identified in the transcriptome of the cattle tick Rhipicephalus microplus (Rm-AURKA and Rm-AURKB) containing the aurora kinase-specific domain. For both isoforms, the highest number of AURK coding transcripts is found in ovaries. Based on deduced amino acid sequences, it was possible to identify non-conserved threonine residues which are essential to AURK functions in vertebrates and which are not present in R. microplus sequences. A pan AURK inhibitor (CCT137690) caused cell viability decline in the BME26 tick embryonic cell line. In silico docking assay showed an interaction between Aurora kinase and CCT137690 with exclusive interaction sites in Rm-AURKA. The characterization of exclusive regions of the enzyme will enable new studies aimed at promoting species-specific enzymatic inhibition in ectoparasites.

Ticks prefer specific feeding sites on a host that are influenced by host–tick and tick–tick interactions. This study focused on the spatiotemporal distribution of ticks in Hokkaido sika deer, an important tick host in Hokkaido, Japan. Tick sampling was performed on the sika deer in the Shiretoko National Park between June and October 2022. Ticks were collected from 9 different body parts of the deer to compare their attachment site preferences. Interspecific and intraspecific relationships among ticks were examined using co-occurrence analysis. The collected ticks were nymphal and adult stages of 4 species: Ixodes ovatus, Ixodes persulcatus, Haemaphysalis japonica and Haemaphysalis megaspinosa. Seasonal variations in tick burden were observed, with I. persulcatus and I. ovatus peaking in June and declining towards October; H. japonica showing low numbers in July and August and increasing from September; and H. megaspinosa appearing from September onwards with little variation. Attachment site preferences varied among species, with a significant preference for the pinna in I. ovatus and I. persulcatus. Haemaphysalis japonica was mainly found on the body and legs between June and August, and shifted to the pinna from September. Haemaphysalis megaspinosa showed a general preference for areas other than the legs. Co-occurrence analysis revealed positive, negative and random co-occurrence patterns among the tick species. Ticks of the same genus and species exhibited positive co-occurrence patterns; I. ovatus showed negative co-occurrence patterns with Haemaphysalis spp. This study revealed the unique attachment site preferences and distinct seasonal distributions of tick species in the Hokkaido sika deer.

Although 12 soft tick species (Argasidae) are native to Australia, the ecology of most is poorly known. Argas dewae parasitizes several insectivorous bat species and has been recorded on humans. Therefore, understanding its ecology is crucial for wildlife health management and public health preparedness. To address this knowledge gap, A. dewae populations were monitored from 2 bat hosts (Chalinolobus gouldii and Austronomus australis) using bat boxes at 3 sites in Victoria, Australia, for 28 months (July 2005–December 2007). A phenological profile undertaken for A. dewae revealed that tick load on bat hosts increased throughout winter and peaked in the first month of spring, before collapsing and remaining low throughout the drier late spring and summer periods. There was also further investigation of the relationship between 2 response variables (tick infestation risk and tick load) and a range of explanatory variables (body condition index, sex, age class, bioseason, site, bat density per nest box). In C. gouldii, site was the only significant predictor of A. dewae infestation risk, while load was correlated with several variables including age class, sex, bioseason, roost density and body condition index. This paper also reports the first records of A. dewae from 6 bat species in 3 bat families (Miniopteridae: Miniopterus australis; Molossidae: A. australis; Vespertilionidae: Chalinolobus morio, Myotis Macropus, Vespadelus darlingtonia, Vespadelus regulus) and a second record of A. dewae from a human. The first distribution records are presented for A. dewae in South Australia, the Australian Capital Territory and Queensland.

Eleonora's falcon (Falco eleonorae Géné, 1839) is a well-known long-distance migrant of the Afro-Palaearctic flyway, a summer breeder of the Mediterranean region and North-west Africa and a winter resident of Madagascar and surrounding areas, thus characterized as a double endemic. Within the context of a long-term monitoring and conservation programme on Antikythira Island, Greece, which accommodates one of the largest concentrations of breeding pairs of Eleonora's falcons globally, birds were subjected to regular inspections for the presence of ticks from 2017 to 2023. In total, 104 adults and 149 nymphs (all belonging to Haemaphysalis genus) were collected. All ticks, apart from 2 nymphs, exhibited broadly salient palpi and did not possess the pronounced palpal segment 2 spurs or spur-like angles that are characteristic of adults, nymphs and most larvae of Rhipistoma, thus placed them in the Ornithophysalis subgenus. Following comprehensive morphological assessment and genetic analysis of the mitochondrial genome by means of next-generation sequencing of both adult and nymphal stages of the ticks, our empirical findings substantiate the delineation of a previously unclassified species. This taxonomic assignment situates the newly described species within the Ornithophysalis subgenus and the Haemaphysalis doenitzi group, marking its presence for the first time within the Western Palaearctic region.

Ticks represent a major concern for society worldwide. Ticks are also difficult to control, and vaccines represent the most efficacious, safe, economically feasible and environmentally sustainable intervention. The evolution of tick vaccinology has been driven by multiple challenges such as (1) Ticks are difficult to control, (2) Vaccines control tick infestations by reducing ectoparasite fitness and reproduction, (3) Vaccine efficacy against multiple tick species, (4) Impact of tick strain genetic diversity on vaccine efficacy, (5) Antigen combination to improve vaccine efficacy, (6) Vaccine formulations and delivery platforms and (7) Combination of vaccines with transgenesis and paratransgenesis. Tick vaccine antigens evolved from organ protein extracts to recombinant proteins to chimera designed by vaccinomics and quantum vaccinomics. Future directions will advance in these areas together with other novel technologies such as multiomics, AI and Big Data, mRNA vaccines, microbiota-driven probiotics and vaccines, and combination of vaccines with other interventions in collaboration with regions with high incidence of tick infestations and tick-borne diseases for a personalized medicine approach.

Ticks transmit pathogens and harbour non-pathogenic, vertically transmitted intracellular bacteria termed endosymbionts. Almost all ticks studied to date contain 1 or more of Coxiella, Francisella, Rickettsia or Candidatus Midichloria mitochondrii endosymbionts, indicative of their importance to tick physiology. Genomic and experimental data suggest that endosymbionts promote tick development and reproductive success. Here, we review the limited information currently available on the potential roles endosymbionts play in enhancing tick metabolism and fitness. Future studies that expand on these findings are needed to better understand endosymbionts’ contributions to tick biology. This knowledge could potentially be applied to design novel strategies that target endosymbiont function to control the spread of ticks and pathogens they vector.

Ticks are a group of blood-sucking ectoparasites that play an important role in human health and livestock production development as vectors of zoonotic diseases. The phylogenetic tree of single genes cannot accurately reflect the true kinship between species. Based on the complete mitochondrial genome analysis one can help to elucidate the phylogenetic relationships among species. In this study, the complete mitochondrial genome of Dermacentor steini (isolate Longyan) was sequenced and compared with the mitochondrial genes of 3 other Chinese isolates (Nanchang, Jinhua and Yingtan). In Dermacentor steini 4 isolates had identical or similar mitochondrial genome lengths and an overall variation of 0.76% between sequences. All nucleotide compositions showed a distinct AT preference. The most common initiation and stop codons were ATG and TAA, respectively. Fewer base mismatches were found in the tRNA gene of D. steini (isolate Longyan), and the vicinity of the control region and tRNA gene was a hot rearrangement region of the genus Dermacentor. Maximum likelihood trees and Bayesian trees indicate that D. steini is most closely related to Dermacentor auratus. The results enrich the mitochondrial genomic data of species in the genus Dermacentor and provide novel insights for further studies on the phylogeographic classification and molecular evolution of ticks.

Tick-borne encephalitis (TBE) is an emerging vector-borne disease in Europe. The aim of the study was to evaluate sequelae and to analyse the potential risk factors predisposing to sequelae development. We performed a retrospective analysis of medical records of 1072 patients who received a 1-month follow-up appointment after hospital discharge. Medical data, such as patients’ age, gender, place of living, subjective complaints, neurological and psychiatric sequelae were evaluated twice: at the moment of discharge and at follow-up visits 1 month after discharge. We observed that sequelae may affect 20.6% of TBE patients. Subjective sequelae were more frequent than subjective complaints during the hospitalisation (P < 0.001), while objective neurological symptoms during the hospitalisation were more pronounced than neurological sequelae (P < 0.001). Patients with meningoencephalomyelitis were predisposed to neurological complications, while subjective symptoms were more common in meningoencephalitis. Independent risk factors for sequelae development were: age and cerebrospinal fluid (CSF) protein concentration. The risk of late neurological complications persisting was increased in patients with higher CSF protein concentration. Based on the results of our study we concluded that, there is a need for a better vaccination program, which would prevent the development of sequelae.

Parasites of the genus Trypanosoma are unicellular flagellated microorganisms of the Trypanosomatidae. This study describes an isolate of the genus Trypanosoma naturally infecting Rhipicephalus microplus ticks, characterized through molecular, morphological and biological analysis. Trypanosome cultures, designated strain P1RJ, were obtained by isolation from R. microplus haemolymph in cultures of the tick cell line IDE8. After isolation, strain P1RJ grew well axenically in L15B medium at temperatures of 30, 32 and 34 °C. The new trypanosome remained stable in axenic culture over 14 passages in L15B at 30 °C and was successfully cryopreserved and resuscitated. Morphometric analysis was performed on randomly selected developmental forms. 18S rRNA and 24Sα rDNA sequence analyses confirmed that strain P1RJ is a new species of the genus Trypanosoma. The nucleotide sequences described were submitted to Genbank. Pathogenicity, involvement in vertebrate hosts, epidemiology, developmental cycle and transmission mechanisms of strain P1RJ are still unknown. Therefore, more studies will be necessary to determine life cycle aspects of this trypanosome, for which we propose the name Trypanosoma rhipicephalis sp. nov.

East Africa is a global hot spot for the diversity of ixodid ticks. As ectoparasites and as vectors of pathogens, ticks negatively affect the well-being of humans, livestock and wildlife. To prevent tick infestations, livestock owners and managers typically treat livestock with acaricides that kill ticks when they attempt to feed on livestock hosts. Because of the costs of preventing and mitigating tick parasitism, predicting where and when ticks will be abundant is an important challenge in this region. We used a 7-year monthly record of tick abundance on large experimental plots to assess the effects of rainfall, wildlife and cattle on larvae, nymphs and adults of two common tick species, Rhipicephalus pulchellus and Rhipicephalus praetextatus. Nymphal and adult ticks were more abundant when there had been high cumulative rainfall in the prior months. They were less abundant when cattle were present than when only large wild mammals were. Larval abundance was not affected by the presence of cattle, and larvae did not appear to be sensitive to rainfall in prior months, though they were less abundant in our surveys when rainfall was high in the sampling month. The challenges of managing ticks in this region are being exacerbated rapidly by changes in rainfall patterns wrought by climate change, and by overall increases in livestock, making efforts to predict the impacts of these drivers all the more pressing.

The distribution of Hepatozoon canis mainly encompasses areas where its main tick vector, Rhipicephalus sanguineus sensu lato, is present. However, the detection of this pathogen in dogs, foxes and golden jackals well outside the areas inhabited by this tick species reinforced the hypothesis that additional ixodids are involved in the life cycle and transmission of this protozoon. The present study provides, for the first time, data supporting the sporogonic development of H. canis in specimens of Rhipicephalus turanicus collected from a naturally infected fox from southern Italy. The epidemiological role of R. turanicus as a vector of H. canis is discussed, along with information on the potential use of cell cultures for the experimental infection with H. canis sporozoites. The in vitro infection of canine leucocytes by sporozoites from ticks is proposed as a potential tool for future in-depth studies on the biology of H. canis.

Climate change experts predict the number of nuisance-biting arthropods in England will increase but there is currently no known surveillance system in place to monitor or assess the public health impact of arthropod bites. This retrospective ecological study utilized arthropod bites requiring healthcare from five national real-time syndromic surveillance systems monitoring general practitioner (GP) consultations (in-hours and out-of-hours), emergency department (ED) attendances and telephone calls to remote advice services to determine baseline incidence in England between 2000 and 2013 and to assess the association between arthropod bites and temperature. During summer months (weeks 20–40) we estimated that arthropod bites contribute a weekly median of ~4000 GP consultations, 750 calls to remote advice services, 700 ED and 1300 GP out-of-hours attendances. In all systems, incidence was highest during summer months compared to the rest of the year. Arthropod bites were positively associated with temperature with incidence rate ratios (IRRs) that ranged between systems from 1·03 [95% confidence interval (CI) 1·01–1·06] to 1·14 (95% CI 1·11–1·16). Using syndromic surveillance systems we have established and described baseline incidence of arthropod bites and this can now be monitored routinely in real time to assess the impact of extreme weather events and climate change.

The mainstream forestry policy in many European countries is to convert coniferous plantations into (semi-natural) deciduous woodlands. However, woodlands are the main habitat for Ixodes ricinus ticks. Therefore, assessing to what extent tick abundance and infection with Borrelia spirochetes are affected by forest composition and structure is a prerequisite for effective prevention of Lyme borreliosis. We selected a total of 25 pine and oak stands, both with and without an abundant shrub layer, in northern Belgium and estimated tick abundance between April and October 2008–2010. Additionally, the presence of deer beds was used as an indicator of relative deer habitat use. Borrelia infections in questing nymphs were determined by polymerase chain reactions. The abundance of larvae, nymphs, and adults was higher in oak stands compared to pine stands and increased with increasing shrub cover, most likely due to differences in habitat use by the ticks' main hosts. Whereas tick abundance was markedly higher in structure-rich oak stands compared to homogeneous pine stands, the Borrelia infection rates in nymphs did not differ significantly. Our results indicate that conversion towards structure-rich deciduous forests might create more suitable tick habitats, but we were unable to detect an effect on the infection rate.

Although widely used, the term repellency needs to be employed with care when applied to ticks and other periodic or permanent ectoparasites. Repellency has classically been used to describe the effects of a substance that causes a flying arthropod to make oriented movements away from its source. However, for crawling arthropods such as ticks, the term commonly subsumes a range of effects that include arthropod irritation and consequent avoiding or leaving the host, failing to attach, to bite, or to feed. The objective of the present article is to highlight the need for clarity, to propose consensus descriptions and methods for the evaluation of various effects on ticks caused by chemical substances.

Comparisons of successful and failed attempts to eradicate livestock ticks reveal that the social context of farming and management of the campaigns have greater influence than techniques of treatment. The biology of ticks is considered principally where it has contributed to control of ticks as practiced on farms. The timing of treatments by life cycle and season can be exploited to reduce numbers of treatments per year. Pastures can be managed to starve and desiccate vulnerable larvae questing on vegetation. Immunity to ticks acquired by hosts can be enhanced by livestock breeding. The aggregated distribution of ticks on hosts with poor immunity can be used to select animals for removal from the herd. Models of tick population dynamics required for predicting outcomes of control methods need better understanding of drivers of distribution, aggregation, stability, and density-dependent mortality. Changing social circumstances, especially of land-use, has an influence on exposure to tick-borne pathogens that can be exploited for disease control.

A total of 41 ticks were collected from 15 quokkas on Bald Island and 2 ticks from a Gilbert's potoroo from Two Peoples Bay. Three species of Ixodid ticks Ixodes australiensis, Ixodes hirsti and Ixodes myrmecobii were identified on the quokkas known to have a high prevalence of Trypanosoma copemani. Tick faeces from ticks isolated from 8 individual quokkas and a Gilbert's potoroo were examined with one identified as positive for trypanosomes. Faecal examination revealed trypanosomes similar to in vitro life-cycle stages of T. copemani. In total 12 ticks were dissected and trypanosomes found in sections of their midgut and haemolymph, 49 and 117 days after collection. Tick faeces, salivary glands and midguts from I. australiensis were screened using an 18S rRNA PCR with amplification seen only from the midguts. Sequencing showed 100% homology to T. copemani (genotype A) and 99·9% homology to the wombat (AII) isolate of T. copemani. Trypanosomes were only detected in I. australiensis as neither I. hirsti nor I. myrmecobii survived the initial 30-day storage conditions. We therefore identify a vector for T. copemani as I. australiensis and, given the detection of trypanosomes in the faeces, suggest that transmission is via the faecal-oral route.

Glycogen synthase kinase-3 (GSK-3) is classically described as a key enzyme involved in glycogen metabolism in mammals. It has been shown to be highly conserved among several organisms, mainly in the catalytic domain region. This enzyme has already been described in Rhipicephalus (Boophilus) microplus and the ovaries of females appeared to be the major site of GSK-3 transcription. The treatment with GSK-3 specific inhibitor (alsterpaullone, bromo-indirubin-oxime 6 and indirubin-3-oxime) caused a reduction in oviposition and egg hatching in completely engorged female ticks. The effect was more pronounced in partially engorged females when alsterpaullone was administrated by artificial capillary feeding. Moreover, GSK-3 gene silencing by RNAi in partially engorged females reduced significantly both oviposition and hatching. The study of tick embryogenesis and proteins that participate in this process has been suggested as an important means for the development of novel strategies for parasite control. GSK-3 is an essential protein involved in embryonic processes and for this reason it has already been suggested as a possible antigen candidate for tick control.

Objective. Expression of the gene encoding Der-p2 allergen-like protein in the castor bean tick Ixodes ricinus is induced by blood intake. Tick Der-p2 allergen-like protein belongs to a diverse family of ML proteins that includes major allergens of house dust mites, human MD-2 or similar proteins from Drosophila melanogaster. In ticks, genes encoding proteins belonging to the ML protein family were identified, but their protein products have not been characterized yet. Methods. A gene encoding tick Der-p2 allergen-like protein was amplified from cDNA of engorged I. ricinus female using the gene-specific primers designed on a basis of partial sequences of related allergen-like genes. The tissue and state specific patterns of expression of the gene were analysed. The IgE binding activity of the produced recombinant protein was studied by use of ELISA. Results. Analysis of the expression pattern showed that the gene encoding the tick Der-p2 allergen-like protein is strongly induced by the bloodmeal in gut and haemolymph throughout all tick developmental stages. Der-p2 allergen-like protein possesses a putative lipid-binding site, according to the comparisons with the related proteins. The ability of tick Der-p2 allergen-like protein to bind immunoglobulin E (IgE) was revealed. Discussion. The presence of a putative lipid-binding domain in Der-p2 allergen-like protein and its ability to interact with IgE might indicate the involvement of the protein in the tick's immune response.

Many vector-borne pathogens whose primary vectors are generalists, such as Ixodid ticks, can infect a wide range of host species and are often zoonotic. Understanding their transmission dynamics is important for the development of disease management programmes. Models exist to describe the transmission dynamics of such diseases, but are necessarily simplistic and generally limited by knowledge of vector population dynamics. They are typically deterministic SIR-type models, which predict disease dynamics in a single, non-spatial, closed patch. Here we explore the limitations of such a model of louping-ill virus dynamics by challenging it with novel field data. The model was only partially successful in predicting Ixodes ricinus density and louping-ill virus prevalence at 6 Scottish sites. We extend the existing multi-host model by forming a two-patch model, incorporating the impact of roaming hosts. This demonstrates that host movement may account for some of the discrepancies between the original model and empirical data. We conclude that insights into the dynamics of multi-host vector-borne pathogens can be gained by using a simple two-patch model. Potential improvements to the model, incorporating aspects of spatial and temporal heterogeneity, are outlined.