ABSTRACT
Hydatid cyst is located in human and some animal visceral organs such as liver and lung. The disease is considered as a medical, veterinary and economical problem in endemic area. When the hydatid cyst is ruptured, protoscolices from inside the cyst may spread out to other parts of the body and develops a new cyst named secondary hydatid cyst. In this research in an attempt to prevent secondary hydatid cyst, protective potential of protoscolices surface antigens extracted with different detergents has been investigated in animal model. In this experimental study, groups of Balb/C mice were immunized intra-peritoneally with protoscolices homogenate and three detergent [SDS, Tween and Triton x-100] extracted protoscolices surface antigens and alum as adjuvant. These mice were then boosted two times with the same antigens fortnightly. Control mice were simultaneously injected with alum alone- Two weeks following the last injection all the mice in cases and control groups were challenged with live protoscolices. Three months afterward all the mice in case and control groups were sacrificed and their peritoneal cavities were explored for hydatid cysts The mean of developed cyst number in mice injected with protoscolices homogenate was 3 +/- 2, while in control group the mean of developed cysts number was 5.8 +/- 1.7 [p< 0.02]. The mean of developed cyst number in mice injected with SDS, Tween and Triton x-100 extracted protoscolices surface antigens was 3, 3.6 and 3.4, respectively, while the mean of developed cyst number in control group was 5.8. The mean of cyst number in cases and control groups was different and this difference was statistically significant. Results of this investigation revealed that protoscolices homogenate antigens and some detergent extracted antigens are protective against secondary hydatid cyst infection