Evaluation of the Immunogenic Response to a Recombinant Anti-Tick Vaccine (GavacTM) against Hyalomma dromedarii and H. anatolicum anatolicum (Acari: Ixodidae) in the Sudan.

الموضوعات

طب

الملخص

This study was conducted, under controlled conditions, to evaluate the level ofimmunity acquired by rabbits and camels against experimental infestations by adults ofHyalomma dromedarii and H. a. anatolicum after being immunized by a vaccinecommercially known as GavacTM. This vaccine was developed in Cuba for control of thecattle tick Boophilus microplus. The base of this vaccine is a glycoprotein moleculefound on the midguts of B. microplus. This molecule was isolated and expressed using ayeast called Pichia pastoris to produce the recombinant form.In this study immunization was carried out following the manufacturer’srecommendations as follows; initial dose on week (0), first booster on week (4) andsecond booster on week (7).Immunization of rabbits and camels with this vaccine induced a significant degreeof protection against experimental infestation by adults of H. dromedarii and H. a.anatolicum compared with the control groups. Acquired immunity developed by thisvaccine was assessed by monitoring tick developmental performances of ticks fed onimmunized hosts compared with those fed on the control groups. The study showed thatbiological parameters of ticks fed on the immunized group were significantly affected bythe vaccine through the antibodies which were produced in response to immunization byBm86 antigen. Resistance acquired was expressed as reduction in mean engorgementweights, mean egg mass weights, hatchability percentages and prolongation of feedingperiods, preoviposition periods, oviposition periods of tick females fed on immunizedanimals. This finding indicates that this vaccine may be effectively incorporated in tickcontrol programmes.Monitoring of humoral response after vaccination was carried out using ELISA tocompare serum samples collected from the experimental and control groups after thesecond booster. Despite homogeneity of response within each species of animals, resultsof ELISA (after cut-off determination) revealed that the hosts responded to the vaccineand produced high levels of antibodies against the antigen yielding mean optical density0.22 and 0.46 for vaccinated rabbits and camels respectively. However, control groupsshow mean optical densities reaching 0.06 and 0.095 for rabbits and camels respectively.XIIITo follow up the dynamics of produced antibodies, serum samples were collectedfollowing the vaccination schedule (weeks 0, 4 and 7), but prior to vaccine injection,beside these, samples on weeks 9 and 13 of the experiment were also collected. Rabbits’antibody levels reached a peak on week 4 and another peak 6 weeks after the secondbooster, while camels started to respond after the first booster and antibody levelsreached a peak 2 weeks after the second booster of the vaccine and then started to decline4 weeks later (week 13).Histopathological sections of attachment sites 96 hours post attachment, of H.dromedarii and H. a. anatolicum on immunized rabbits compared with those taken fromnon-immunized ones, revealed no specific inflammatory cell types associated withsensitization with Bm86 antigen. This observation probably indicates that the resultsobtained from vaccination trials might be totally attributed to the effect of the Bm86molecule. On other hand, this finding may indicate that cell-mediate immunity may actseparately act depending on factors such as tick species, host species and degree ofexposure. Future investigations on the relation between humoral and cellular immunitymay be needed on this aspects.

روابط وملفات

التعريف والنوع

رقم الوثيقة

027a7f80-50a1-480d-901d-925a295da34f

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل ماجيستير

نوع الملف

pdf text

أسماء الملفات

1639334_1.pdf

بيانات النشر

ألقاب المؤلفين

[{"name_ar":"ابراهيم ادم","title_ar":"اعداد","title_en":"Preparation"},{"name_ar":"شوقي حسن","title_ar":"اشراف","title_en":"Supervision"},{"name_ar":"عبدالرحيم الحسين","title_ar":"اشراف","title_en":"Supervision"}]

اللغة

English

المصدر والدورية

اسم المصدر

Evaluation of the Immunogenic Response to a Recombinant Anti-Tick Vaccine (GavacTM) against Hyalomma dromedarii and H. anatolicum anatolicum (Acari: Ixodidae) in the Sudan.

المحتوى والصفحات

عدد الصفحات

0

إشراف وإعداد

الإشراف

شوقي حسن, عبدالرحيم الحسين

الإعداد

ابراهيم ادم

الاقتباسات الببليوغرافية