Immunization of rabbits against Hyalomma anatolicum anatolicum using homogenates from unfed immature ticks.

ABSTRACT

Antigens were prepared from unfed larvae and nymphs of H. a. anatolicum as homogenised antigens (HLAg and HNAg, respectively). Five rabbits each were inoculated, s.c. with 8.56 mg HLAg and 9.34 mg HNAg in 3 divided doses. Following immunisation rabbits developed significant level of protective immunity to infestation with adults of this species. Significant reduction in engorged percentage and weights of engorged females and egg masses were observed in females fed on immunized rabbits, compared to that of female ticks fed on control rabbits. The engorgement period was also increased significantly. However, conversion efficiency indices remained unaffected. Larval antigen immunized rabbits showed significant antibody level from 28-126 days while with HNAg elevated antibody levels were recorded up to 112 days. Further, the rabbits immunized with HLAg had elevated level of antibodies against HLAg, HNAg, and adult antigen in ELISA. But HNAg immunized rabbits had lower levels of antibodies against HLAg and HAAg as compared to values recorded against HNAg. Anti-HLAg and anti-HNAg sera recognised common antigenic bands of 97.4, 85, 66, 47.3, 42 and 31 kDa in homogenates of larvae, nymphs and adults.