A Review of the Taxonomy of Theileria sergenti/buffeli/orientalis Group Parasites in Cattle

application/pdfThe controversial circumstances relating to the classification of the benign Theileria species from Japan, Australia and Britain, which are frequently referred to as T. sergenti/buffeli/orientalis group parasites, was reviewed. Our recent systematic comparisons suggest a possibility that the Japanese T. sergenti (minor piroplasm in common parlance) might be a new species and the Australian T. buffeli and British T. orientalis might belong to one and the same species. The necessity for the review of the genus name for these benign Theileria species was also briefly discussed after the morphological studies of their schizogony.journal articl

RNA Interference – A Powerful Functional Analysis Tool for Studying Tick Biology and its Control

Ticks (Acari: Ixodida) are blood-sucking arthropods globally recognized as vectors of numerous diseases. They are primarily responsible for the transmission of various pathogens, including viruses, rickettsiae, and blood parasites of animals. Ticks are second to mosquitoes in terms of disease transmission to humans. The continuous emergence of tick-borne diseases and acaricide resistance of ticks necessitates the development of new and more effective control agents and strategies; therefore, understanding of different aspects of tick biology and their interaction with pathogens is very crucial in developing effective control strategies. RNA interference (RNAi) has been widely used in the area of tick research as a versatile reverse genetic tool to elucidate the functions of various tick proteins. During the past decade, numerous studies on ticks utilized RNAi to evaluate potentially key tick proteins involved in blood feeding, reproduction, evasion of host immune response, interaction with pathogens, and pathogen transmission that may be targeted for tick and pathogen control. This chapter reviewed the application of RNAi in tick research over the past decade, focusing on the impact of this technique in the advancement of knowledge on tick and pathogen biology

Advances in the artificial feeding of Ornithodoros moubata (Acari: Ixodidae) and the follow up of its life cycle after feeding on fetal bovine serum

application/pdfOrnithodoros moubata was fed artificially through a parafilm membrane with two types of artificial meals. The first type was composed of bovine and horse red blood cells suspended in phosphate buffered saline or fetal bovine serum (FBS). The second type was composed of FBS alone. Engorgement and post engorgement survival rates of the ticks after feeding on the two types of meals were compared and analysed statistically. FBS was found to be superior to red blood cell meals. Eventually two batches of FBS from different manufacturers were used to feed the ticks through artificial membrane. Engorgement and post engorgement survival rates were again compared and analysed statistically. There was no significant difference between the two lots. Finally O. moubata was fed on FBS and successful reproductive cycle followed up to the third generation.journal articl

Longistatin, a Plasminogen Activator, Is Key to the Availability of Blood-Meals for Ixodid Ticks

Ixodid ticks are notorious blood-sucking ectoparasites and are completely dependent on blood-meals from hosts. In addition to the direct severe effects on health and productivity, ixodid ticks transmit various deadly diseases to humans and animals. Unlike rapidly feeding vessel-feeder hematophagous insects, the hard ticks feed on hosts for a long time (5−10 days or more), making a large blood pool beneath the skin. Tick's salivary glands produce a vast array of bio-molecules that modulate their complex and persistent feeding processes. However, the specific molecule that functions in the development and maintenance of a blood pool is yet to be identified. Recently, we have reported on longistatin, a 17.8-kDa protein with two functional EF-hand Ca++-binding domains, from the salivary glands of the disease vector, Haemaphysalis longicornis, that has been shown to be linked to blood-feeding processes. Here, we show that longistatin plays vital roles in the formation of a blood pool and in the acquisition of blood-meals. Data clearly revealed that post-transcriptional silencing of the longistatin-specific gene disrupted ticks' unique ability to create a blood pool, and they consequently failed to feed and replete on blood-meals from hosts. Longistatin completely hydrolyzed α, β and γ chains of fibrinogen and delayed fibrin clot formation. Longistatin was able to bind with fibrin meshwork, and activated fibrin clot-bound plasminogen into its active form plasmin, as comparable to that of tissue-type plasminogen activator (t-PA), and induced lysis of fibrin clot and platelet-rich thrombi. Plasminogen activation potentiality of longistatin was increased up to 4 times by soluble fibrin. Taken together, our results suggest that longistatin may exert potent functions both as a plasminogen activator and as an anticoagulant in the complex scenario of blood pool formation; the latter is critical to the feeding success and survival of ixodid ticks

A Continuing Exploration of Tick–Virus Interactions Using Various Experimental Viral Infections of Hard Ticks

To fully unravel the ixodid ticks’ role as vectors of viral pathogens, their susceptibility to new control measures, and their ability to develop acaricide resistance, acclimatization of ticks under laboratory conditions is greatly needed. However, the unique and complicated feeding behavior of these ticks compared to that of other hematophagous arthropods requires efficient and effective techniques to infect them with tick-borne viruses (TBVs). In addition, relatively expensive maintenance of animals for blood feeding and associated concerns about animal welfare critically limit our understanding of TBVs. This mini review aims to summarize the current knowledge about the artificial infection of hard ticks with viral pathogens, which is currently used to elucidate virus transmission and vector competence and to discover immune modulators related to tick–virus interactions. This review will also present the advantages and limitations of the current techniques for tick infection. Fortunately, new artificial techniques arise, and the limitations of current protocols are greatly reduced as researchers continuously improve, streamline, and standardize the laboratory procedures to lower cost and produce better adoptability. In summary, convenient and low-cost techniques to study the interactions between ticks and TBVs provide a great opportunity to identify new targets for the future control of TBVs

Development of DNA Probes for the Detection and Identification of Babesia ovata

application/pdfjournal articl

Rapid and Sensitive Method for Detection of Newly Isolated Babesia Parasite (Babesia sp.1) in the Anticipated Vector-Tick Using the Polymerase Chain Reaction Technique

application/pdfjournal articl

DNA Probes for Detection of Babesia ovata or the Babesia sp.1, A Newly Isolated Bovine Babesia Parasite in Japan

application/pdfjournal articl