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Powassan Virus
Published in Sunit K. Singh, Daniel Růžek, Neuroviral Infections, 2013
Laura D. Kramer, Alan P. Dupuis, Norma P. Tavakoli
Protoype POWV and DTV lineage strains are maintained in nature in a transmission cycle involving ixodid ticks and small mammals. A systemic viremia within the vertebrate host may not be necessary for efficient transmission. Co-feeding or non-viremic transmission, proposed and demonstrated in the laboratory with TBEV by Labuda et al. (1993), may be sufficient to maintain POWV in nature. This has been modeled for POWV for long-term maintenance in natural foci (Nonaka et al. 2010). Another mode of virus transmission, transovarial transmission (female to larvae via the egg), has been documented in the laboratory with Ix. ricinus, Dermacentor reticulatus, H. longicornis (neumanni), and other ticks and various strains of TBEV (Naumov et al. 1980; Danielova et al. 2002).
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
Natural killer (NK) cells are another population of lymphocytes that participate in innate immunity and early defence against viruses and other intracellular microbes (Biron et al., 1999). These lymphocytes have also been the target of tick-induced immunosuppression (Kopecky and Kuthejlova, 1998; Kubes et al., 1994, 2002). SGE from female Dermacentor reticulatus (Kubes et al., 1994), and Amblyomma variegatum and Haemaphysalis inermis to a lesser extent (Kubes et al., 2002), inhibited the activity of human NK cells when compared with that observed for SGE preparations from unfed ticks. Although NK cells are not known to have direct effector functions in tick-acquired immunity, they could potentially contribute to a Thl immune response by production of IFN-γ, a Thl effector cytokine that stimulates cell-mediated immunity, such as delayed-type hypersensitivity, macrophage activation and inflammatory responses. Also, their role in responding to tick-borne infectious agents can be potentially important.
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
Isolated organs from adult, and occasionally nymphal, ticks have been used in a variety of short- and long-term studies focusing on tick physiology, pathogen propagation and/or development, and tick-pathogen interactions. The earliest studies, carried out on fed nymphal and adult female organs (ovaries, salivary glands, midguts, and Malpighian tubules) from ticks of the genera Hyalomma and Rhipicephalus, demonstrated survival, determined by observation of peristalsis and examination of histological preparations, for 13–58 days in vitro [66]. Subsequent studies focussed on salivary glands; short-term organ cultures were used to unravel the mechanisms of salivation [67,68], and an elegant technique was developed for collection of saliva secreted by individually excised glands for up to 14 days in vitro [69]. Excised salivary glands, and occasionally other tissues, such as midgut, synganglion, ovaries, and Malpighian tubules, subsequently used in studies on pathogen metabolism, development, and interaction with host tissues [58,70–73], were reported to survive for, at most, 9–12 days. However, when co-cultivated with tick cell lines, adult organs from some tick species may maintain viability as shown by midgut peristalsis for up to four months (Bell-Sakyi, unpublished observations of unfed adult Dermacentor reticulatus organs co-cultivated with BME/CTVM23 cells).
Seropositivity to Midichloria mitochondrii (order Rickettsiales) as a marker to determine the exposure of humans to tick bite
Published in Pathogens and Global Health, 2019
Valentina Serra, Viktoria Krey, Christina Daschkin, Alessandra Cafiso, Davide Sassera, Horst-Günter Maxeiner, Letizia Modeo, Carsten Nicolaus, Claudio Bandi, Chiara Bazzocchi
The possibility that seropositivity to M. mitochondrii could represent a serological marker for I. ricinus bite in humans had already been suggested, based on a study limited to a total of 80 Italian patients with a diagnosis for LD [16]. Here we have extended this screening to a total of 274 subjects from several European countries, with different expected levels of I. ricinus exposure. In general, the tick species that most frequently parasitize companion animals and humans in Europe are I. ricinus, Rhipicephalus sanguineus sensu lato and Dermacentor reticulatus [33,34]. Thus, considering that R. sanguineus s.l. and D. reticulatus have never been shown to harbor bacteria of the Midichloriaceae family [35,36], positivity to rFliD is with a high chance an indicator of an I. ricinus bite.
Prevalence of Spotted Fever Group Rickettsia in North-Eastern Poland
Published in Infectious Diseases, 2019
Karol Borawski, Justyna Dunaj, Piotr Czupryna, Sławomir Pancewicz, Renata Świerzbińska, Agnieszka Żebrowska, Anna Moniuszko-Malinowska
The north-eastern Poland is an endemic region of tick – borne diseases. The incidence on Lyme borreliosis and tick-borne encephalitis (TBE) is significantly higher in comparison to other regions of the country [1]. Most common ticks in Poland – Ixodes ricinus and Dermacentor reticulatus can also transmit other pathogens like Anaplasma phagocytophilum [2], Babesia species [3], Coxiella burnetii, Rickettsiales [4–6] or Candidatus Neoehrlichia mikurensis [7].