Observation On The Life Cycle And Analysis Of Specific Antigen Of Pseudodactylogyrus Spp. From Eel

Pseudodactylogyrosis is a severe disease that threatens the eel industry. Due to the repeated and persistent infection of the Pseudodactylogyrosis, the anthelmintics were frequently applied on controlling the branchial parasite Pseudodactylogyrus in eel, which caused the Pseudodactylogyrus extensively resisted to many anthelmintics, and made the prophylaxes and therapy of Pseudodactylogyrosis became a thorny matter. In the present article, observation on the life cycle and analysis of the structure proteins' immunogenicity of Pseudodactylogyrus are described, and the relationship between parasite infection and the host immune responses are discussed. The purpose of the project was attempted to seek a safer and more effective approaches to prevent Pseudodactylogyrosis by means of immunology technique.Life cycle of Pseudodactylogyrus: The results indicate that the new egg was forming in the course of ovulating. Temperature is the decisive factor that influences the egg hatch of Pseudodactylogyrus. There is another mode that hatching out was started with rear-end of oncomiracidia. Cilium of oncomiracidia is distributed only covered from belly to back area about 2/3, not around the waist. Oncomiracidia has the phototaxises. Transient treated with high concentrations of salt solution can cease development of egg.Antisera preparation and the parasite antigens analysis: The mouse and eel antisera were prepared with the sonicated Pseudodactylogyrus as immunogen. The antibody titers of mouse and eel antisera test by ELISA were 1:51200 and 1:3200 respectively. SDS-PAGE and Western blot analysis show that sonicated Pseudodactylogyrus contained seven major structural proteins with molecular weight 16kDa, 21kDa, 29kDa, 37kDa, 43.5kDa, 68kDa, 110kDa respectively, among them the 29kDa polypeptide is an abundant protein. The 25kDa, 43.5kDa, 62kDa and 81kDa proteins of sonicated Pseudodactylogyrus were recognized by the sera of both immuned eel and recovered eel on Western blot. Significantly elevated anti-Pseudodactylogyrus antibodies were detected in the immuned fish, it seemed that there was no correlation between antibody titers of immuned eel and parasite burdens. The immunofluorescence test revealed that, both sides in the middle part of Pseudodactylogyrus, especially the areas where adjacent yolk gland showed stronger fluorescence. In addition, some bright fluorescence spot were observed on the head and tail of individual Pseudodactylogyrus.Conclusion: There is another mode that hatching out was started with rear-end of...