Immunization of cross-bred cattle against Hyalomma anatolicum anatolicum by purified antigens.

Extracts prepared from unfed larvae of Hyalomma anatolicum anatolicum were purified by immunoaffinity chromatography using anti-gut IgG as ligand. Affinity purified antigen (Aff-GHLAg) was used to immunize cross-bred (Bos taurus x B. indicus) calves of 6-7 months of age. Immunized calves rejected 70.6% larvae, 54.5% nymphs and 61.9% adults. No significant changes in the engorged weight of females was observed; however, significant decrease in the engorgement weight of larvae and nymphs was recorded. There was a significant decrease in the emerging nymphs (p < 0.05) and adults (p < 0.01) of the tick stages fed on immunized animals. SDS-PAGE analysis revealed three antigenic proteins of 100, 59.4 and 37 kDa responsible for induction of resistance in the host.