Upcoming and future strategies of tick control: a review.

Ticks are distributed worldwide and significantly impact human and animal health. Due to severe problems associated with the continuous use of acaricides on animals, integrated tick management is recommended. Increasing public health concern over the tick-borne diseases demands the strategic control of ticks on animals that transmit diseases to human beings. Immunological control of tick vector of Kyasanur Forest Disease (KFD) on cattle and other wild reservoir hosts is one of the possible alternative strategy for reducing the transmission of KFD to man. Chemical-vaccine synergies have been demonstrated and a combination of chemical and vaccine for tick and tick-borne disease control has been identified as a sustainable option. Studies have suggested the possibility of vaccine strategies directed towards both tick control and transmission of pathogens. Besides tick vaccine, use of endosymbionts, which are essential for the survival of arthropod hosts, for the control of tick vectors will be one of the targeted areas of research in near future. India with huge natural resources of herbs and other medicinal plants, the possibilities of developing herbal acaricides is discussed. The future of research directed towards target identification is exciting because of new and emerging technologies for gene discovery and vaccine formulation.

Comparative immunopotentiating properties of saponin and incomplete Freund's adjuvant coupled to affinity purified larval antigen of Hyalomma anatolicum anatolicum.

Comparative immunostimulatory properties of saponin and incomplete Freund's adjuvant (IFA) were studied using affinity purified 39 kDa larval antigen of Hyalomma anatolicum anatolicum. Significant antibody response to 39 kDa antigen was detected in the sera of rabbits immunized with both 39 kDa plus saponin and 39 kDa plus IFA in comparison to their corresponding control animals. Insignificant differences were noted in the antibody response between the animals of two immunized groups. Upon challenge, the animals immunized with 39 kDa plus IFA rejected 76.2 +/- 9.7% of larvae and 45.8 +/- 4.1% of adults while in group of animals injected with 39 kDa plus saponin rejected 80.9 +/- 11.2% of larvae and 47.2 +/- 5.7% of adults.

Immunization of cattle against Hyalomma anatolicum anatolicum using larval antigens.

Development of immunity in cross-bred (Bos taurus x Bos indicus) calves against Hyalomma anatolicum anatolicum, vector of bovine tropical theileriosis, was studied using larval antigen (LS) in Freund's complete adjuvant (FCA). Calves immunized with LS + FCA showed significant rejection of larvae (57.25 +/- 6.8) and nymphs (45.75 +/- 5.16). Abnormally fed larvae (11.4 +/- 0.8) and nymphs (8.25 +/- 1.2) were also recovered from immunized calves. This abnormal feeding may possibly be attributed to their inability to gain access to the blood vessels owing to the host immunological reactions. Consequently, feeding of extravascular fluid leads to white colour of fed ticks. Sera from all immunized calves after a week of immunization were positive for anti-LS antibodies in ELISA. The investigation indicates that LS in FCA enhanced anti-tick immunity.

Identification of gut antigens from female boophilus microplus ticks

Un extracto de intestino de hembras semi-repletas de garrapata Boophilus microplus, fue separado mediante electroforesis SDS-PAGE, identificándose al menos 18 bandas en un rango de peso molecular de 17 a 258 kDa; al practicar el ensayo inmunoenzimático de Dig-glicanos, las proteínas por arriba de 58 kDa, mostraron estar asociadas con carbohidratos. El análisis de Western blot permitió identificar cinco antígenos de intestino con un peso molecular en un rango de 89 a 208 kDa, utilizando un suero de conejo anti-intestino de garrapata. Estos antígenos fueron localizados en la superficie del intestino de la garrapata mediante inmunofluorescencia indirecta en cortes histológicos del mismo intestino. Los tres antígenos (99, 141, 189 KDa) identificados, son diferentes de los previamente reportados en la literatura y podrían ser utilizados en pruebas para inducir inmunidad en contra de las garrapatas en ganado bovino

Differences in the acquired resistance of dogs, hamsters, and guinea pigs to repeated infestations with adult ticks Rhipicephalus sanguineus (Acari: Ixodidae)

Grupos experimentais de cäes, hamsters e cobaias sem contato anterior com carrapatos, sofreram três infestaçöes consecutivas por carrapatos Rhipicephalus sanguineus adultos e a resistência adquirida comparada com base na variaçäo de alguns dos parâmetros biológicos da fêmea do carrapato. Os resultados mostraram que hamsters e cobaias principalmente, desenvolvem uma reaçäo imune muito eficiente a esta espécie de carrapato como demonstrado por uma queda altamente significativa na taxa de eficiência da fêmea em converter sua reserva alimentar em ovos e larvas da primeira para as segunda e terceira infestaçöes. Já cäes foram incapazes de desenvolver tal resistência. Neste hospedeiro a performance das fêmeas dos carrapatos foi similar durante todas as infestaçöes, havendo até uma tendência de melhora com a sucessäo das infestaçöes. Estes resultados reforçam a necessidade de estudos comparativos sobre a resistência adquirida a carrapatos, envolvendo hospedeiros naturais e näo naturais, como forma de colocar em evidência mecanismos de defesa que possam estar alterados ou ocultos em relaçöes parasita-hospedeiro naturais

Cross-reactivity between hard tick antigens

1. The present study was carried out to determine the target cells and tissues for anti-tick immunoglobulins using an indirect immunohistochemical technique. 2. Sections in triplicate prepared from unfed ticks Rhipicephalus appendiculatus, R. evertsi and Amblyomma variegatum were used to assess the cross-reactivity of serum from guinea pigs naturally infested with these tick species or immunized against them. 3. The sections showed slight (+) to strong ( +) labelling of several structures in the tick body, e.g. salivary gland, gut lumen and malpighian tubules, depending on the serum used. 4. The immune serum resulting from the immunization of guinea pigs with an extract of unfed nymphs of R. appendiculatus ticks showed the most intense cross-reactivity with the sections examined

Perspectivas de controle imunológico de carrapatos parasitos de rebanhos bovinos / Perspectives of immunologic control of ticks parasites of bovine herds

Já dispomos de informaçöes científicas que indicam a viabilidade técnica da produçäo de uma vacina contra carrapatos e outros artrópodes. Buscando alternativa de controle do Boophilus microplus, os autores estudaram essa questäo fundamental e urgente, devido à resistência às drogas e os malefícios de resíduos químicos nos produtos de origem animal e no meio ambiente