Submitted to: American Association of Veterinary Parasitologists
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/2007
Publication Date: 7/14/2007
Citation: Barfield, R.C., Miska, K.B., Jenkins, M.C., Fetterer, R.H., Berezin, V., Bogoyavlenskiy, A., Tolmacheva, V., Makhmudova, N., Khudyakoval, S., Levandovskaya, S., Omirtaeva, E., Zautceva, I., Tustikbaeva, G., Aleksyuk, P. 2007. The evaluation of ISCOMs incorporating triterpene saponins isolated from native plants and the recombinant antigen SO7 for in ovo immunization of chickens against Eimeria tenella infection. American Association of Veterinary Parasitologists. p66. Interpretive Summary:
Technical Abstract: Coccidiosis is an intestinal disease causing significant economic losses to the poultry industry. At present the main emphasis in control of poultry coccidiosis has centered on use of combinations of anticoccidial drugs and various live vaccine preparations. Immunostimulating complexes (ISCOMs) are one of the most effective delivery systems for vaccine preparations stimulating high levels of antibody, cell-mediated and mucosal immune responses. Lipids and adjuvant active triterpene saponins are key components of ISCOMs. Adjuvant active low toxicity triterpene saponins have been isolated from Glycyrrhiza glabra (GG-6) and Aesculus hippocastanum (AH-6), plants indigenous to Kazakhstan, by ethanol extraction and purified using HPLC fractionation. Previous studies indicated that ISCOMs containing crude Eimeria tenella antigens could successfully protect chickens against a challenge infection. In the current study immunization experiments using in ovo injection of antigens were conducted using ISCOMs assembled with a recombinant coccidia antigen SO7, a highly conserved protein associated with the parasite’s refractile body. Antibody production, serum carotenoid and nitrate-nitrite levels, oocyst production and weight gain were measured at day 7 after challenge of birds with 50,000 E. tenella oocysts per bird. The results of the study indicate that ISCOMs containing GG-6 and AH-6 triterpene saponins and SO7 stimulated high levels of humoral immune response, prevented increases in serum carotenoid and nitrate/nitrite levels, reduced oocyst output and prevented reduction in weight gain. These results were equal or superior to immunization using other delivery systems. It was concluded that triterpene saponins GG-6 and AH-6 could be used for preparation of ISCOMs containing recombinant antigens which may be successfully used in the protection of poultry against coccidiosis.