Developing Anti-tick Vaccines
Ticks are responsible for the transmission of viral, bacterial, and protozoal diseases of man and animals and also produce significant economic losses to cattle industry. The use of acaricides constitutes a major component of integrated tick control strat
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Introduction Ticks cause direct and indirect effects in the animals that they parasitize. Direct effects are characterized by anemia, toxic action of bites, loss of appetite, and growth delay, in addition to a diminution in the quality of leathers. The indirect effects are related to the transmission of a great variety of infectious agents by ticks [1], which leads to diseases, diminution of productive yield, or deaths. The annual productivity losses attributed to cattle ticks in the world are around 7 billion USD per year [2]. Chemical methods are commonly employed for tick control [3]. This approach produces resistant ticks, food contamination, and environmental pollution. The use of biological methods is another strategy to control ticks. These are based on the use of hormones and other growth regulators, as well as the use of biological agents as predators, bacteria, nematodes, and fungi. In addition to these two methods, there are also physical methods to control ticks. It has been proved that the development of ticks during the non-parasitic life stage depends largely on the external conditions of humidity and temperature. Meadows with tall vegetation and shrubs provide an ideal habitat for tick development. Heavy grazing reduces vegetation cover and may limit the survival of eggs and larvae [4]. Another physical control method against ticks that has been used is the burning of grasslands, which affects ticks directly by exposure to high temperatures and indirectly by the destruction of the vegetation cover that protects ticks [5]. However, burning constitutes a major risk for the generation of wildfires that have terrible consequences for the environment by destroying wildlife habitat, killing animals that cannot escape, altering biodiversity, with the consequent alterations in the food chain, loss of natural seed banks, loss of organic matter and various
Sunil Thomas (ed.), Vaccine Design: Methods and Protocols, Volume 2: Vaccines for Veterinary Diseases, Methods in Molecular Biology, vol. 1404, DOI 10.1007/978-1-4939-3389-1_17, © Springer Science+Business Media New York 2016
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Alina Rodríguez-Mallon
elements, producing soil erosion, altering water infiltration into the soil, and promoting contamination and sedimentation of watercourses and reservoirs. All these factors endanger human lives, the scenic and recreational value of the natural environment and eventually affect agriculture productivity due to soil impoverishment [6]. Vaccination is considered an alternative to control ectoparasite infestations. The immunological control of ticks is exempt from environmental problems as opposed to others and has prospects of a durable protection [7]. The background of this method is present in nature where there are animals that are genetically resistant to ticks. It has been shown that the resistance is inherited and is increased by selection of animals. For example, European Bos taurus cattle breeds (Swiss, Charolais, Holstein, and Simmental) are more susceptible compared to Bos indicus breeds (Br
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