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Clinical Toxicology of Tick Bites
Published in Jürg Meier, Julian White, Handbook of: Clinical Toxicology of Animal Venoms and Poisons, 2017
Stone1 has reviewed this subject. He noted 4 types of non-paralysing tick toxicoses in domestic animals. The relationship of these with human disease is unclear.Type 1: Fever, profuse moist eczema, anorexia and debilitation, found in cattle, sheep and pigs, in central, eastern and southern Africa, in southern India and Sri Lanka. Associated with the small bontpoot tick, Hyalomma truncatum.Type 2: Rapidly lethal condition affecting young calves and sheep, from the Kalahari and Namibia, caused by the sand tampan (tick), Ornithodoros savignyi.Type 3: Pyrexia, anaemia, wasting and necrosis of lymph nodes, affecting cattle from southern Africa, and associated with massive infestations by the brown ear tick, Rhipicephalus appendiculatus.Type 4: Pyrexia, anorexia, possible liver dysfunction, affecting cattle, from Australia, due to the cattle tick, Boophilus microplus. There is some contention that Type 4 is not a true tick toxicosis.
Comparative aspects of the tick–host relationship: immunobiology, genomics and proteomics
Published in G. F. Wiegertjes, G. Flik, Host-Parasite Interactions, 2004
Francisco J. Alarcon-Chaidez, Stephen K. Wikel
Strategies used in developing anti-tick vaccines currently involve molecular characterization and in vitro expression of proteins secreted in tick saliva or associated with salivary glands (exposed antigens) or even those that do not normally interact with the host immune defences (concealed antigens) such as in tick midgut (Mulenga et al., 2000; Trimnell et al., 2002). In this way, defined subunit vaccines can be produced either by chromatographic purification of the antigen from saliva or salivary gland homogenates or by producing the antigen in a recombinant system (Lee and Opdebeeck, 1999; Mulenga et al., 2000; Willadsen, 2001). Some of the tick antigens that have been characterized using the approach just described include an inhibitor of platelet aggregation from O. moubata, (Keller et al., 1993), anti-haemostatic factors from Ornithodoros savignyi (Joubert et al., 1998) and I. scapularis (Francischetti et al., 2000, 2003; Valenzuela et al., 2000), histamine- and immunoglobulin-binding proteins from R. appendiculatus (Paesen et al., 1999; Wang and Nuttall, 1999), an immunosuppressant protein from D. andersoni (Alarcon-Chaidez et al., 2003; Bergman et al., 2000), and a number of housekeeping genes from B. microplus (Ferreira et al., 2002a, b; Rosa de Lima et al., 2002).
Comparative genome analysis of Alkhumra hemorrhagic fever virus with Kyasanur forest disease and tick-borne encephalitis viruses by the in silico approach
Published in Pathogens and Global Health, 2018
Navaneethan Palanisamy, Dario Akaberi, Johan Lennerstrand, Åke Lundkvist
From univariate and multivariate analyses, the common modes of AHFV transmission included direct contact with the blood of infected animals, like sheep and camel, e.g. while butchering, drinking the raw milk or eating raw meat, or by bites from ticks who have also infected said animals [7]. After the discovery of AHFV, there was no real evidence of the involvement of ticks for the transmission of AHFV, except for the fact that it was phylogenetically clustered within the tick-borne encephalitis virus (TBEV) serocomplex. In 2007, Charrel et al. published the first evidence of the presence of AHFV RNA in Ornithodoros savignyi, a soft tick, isolated from a camel resting place near Jeddah, Saudi Arabia [8]. In 2011, Mahdi et al. published detection of AHFV RNA from O. savignyi and Hyalomma dromedarii (a hard tick) [9]. The study by Charrel et al. also showed that AHFV isolated from ticks form sub-lineages distinct from the ones isolated from humans [8]. Despite detection of AHFV RNA in ticks, transmission from ticks to humans has not yet been confirmed. It is still hypothesized that mosquitos could potentially transmit AHFV, but this is yet to be proven [10,11]. Furthermore, it is poorly understood how it replicates in sheeps and camels, as inoculation of the virus did not show any obvious symptoms in sheep [12]. Since much is unknown about this virus, AHFV is handled either in BSL-3 or BSL-4 labs, depending on the country.
How relevant are in vitro culture models for study of tick-pathogen interactions?
Published in Pathogens and Global Health, 2021
Cristiano Salata, Sara Moutailler, Houssam Attoui, Erich Zweygarth, Lygia Decker, Lesley Bell-Sakyi
TBV are usually associated with specific tick genera or species. For instance, D. andersoni cells support the growth of CTFV [15], while I. scapularis cells are non-permissive to the virus. CTFV produced in BHK-21 cells and inoculated into IDE2 or IDE8 cells, at a multiplicity of infection of one plaque-forming unit (pfu)/cell, failed to replicate in either of the two tick cell lines. Real-time RT-PCR targeting genome segment 9, carried out on RNA extracted 7 and 14 days post-inoculation, showed no evidence of CTFV genome replication (Attoui and Mohd Jaafar, unpublished observation). The choice of the species from which cells are derived is crucial in terms of relevance, as certain TBV can infect cell lines derived from multiple different tick genera/species [74]. For instance, Alkhumra hemorrhagic fever virus, which has been found in Ornithodoros savignyi, replicates in the tick cell lines HAE/CTVM9, RAE/CTVM1, and OME/CTVM24 [202]. Yet detecting viral RNA by RT-PCR, or viral antigens by immunohistochemistry, does not reflect full replication functionality in a particular cell line and/or virus assembly. Indeed, while progeny infectious viruses were detected in both RAE/CTVM1 and OME/CTVM24, none could be detected in HAE/CTVM9, reflecting a probable abortive replication. Recent studies in I. ricinus ticks and cell lines of Kemerovo virus (KEMV), transmitted by I. persulcatus and, rarely, I. ricinus, suggest that the virus replicates in IRE/CTVM20 but not IRE11 or IRE/CTVM19 cells (Migné et al., manuscript in preparation). Despite initial virus titers of >106 pfu/ml produced in IRE/CTVM20 cells, KEMV replication was undetectable after three months. Replication in an arthropod cell line does not imply that the virus can be transmitted by the particular arthropod from which the cells were derived. While insect-borne viruses such as the mosquito-borne alphavirus SFV replicate well in multiple tick cell lines [74,105], the biological significance of this is far from reflecting vector capacities of the parent ticks or inferring relevant data regarding virus–vector interactions in vivo.