Immunization of rabbits against Hyalomma anatolicum anatolicum using larval and nymphal extracts

ABSTRACT

The protective capacity of the crude extracts from larval and nymphal stages of Hyalomma anatolicum anatolicum was examined in the New Zealand white rabbits. The rabbits were randomly divided into 3 groups of five animals. The rabbits in groups 1 and 2 were immunized with crude extracts of larval and nymphal antigens, respectively and group 3 was served as control. Following challenge of each rabbit with 2000 larvae of H. a. anatolicum, engorged nymphs were collected, weighed and then cultured in an incubator. A significant decrease in weight of engorged nymphs was only observed in group 1 that immunized with crude extracts of tick's larvae [P<0.05]. Polypeptide profile of the larval and nymphal extracts was analysed by SDS-PAGE, and antigenic pattern with serum of immunized rabbits was evaluated by Dot and Western blot test. The molecular weight of the fraction of larval extract after SDS-PAGE showed six polypeptide bands as follows 97, 84, 66, 55, 45 and 36 kDa, and in nymphal extract 13 polypeptide bands of 205, 116, 97, 84, 66, 55, 45, 36, 29, 24 and 20 kDa and two bands between 116 and 205 kDa were found. In Western blotting, positive reaction was only observed with sera of group 1 in the bands with 97, 84 and 66 kDa. It seems that the larval extract of H. a. anatolicum can be used as a source of biological material for isolation of protective antigen