Immunoprotection in sheep against Haemonchus contortus using its thiol-purified excretory/secretory proteins

Excretory/Secretory antigen was prepared by culturing live adult worms of Haemonchus contortus in RPMI ۱۶۴۰ medium at a concentration of ۵۰ worms per mL in a culture-flask at ۳۷ ˚C for ۲۴ hr and the culture supernatant was used as antigen. The E/S antigen was purified by thiol-sepharose affinity chromatography. On western blot analysis, it was demonstrated that thiol-purified antigen showed a single reactive band at ۶۶ kDa. In immunization trial, sheep were administered intramuscularly with ۵۰۰ μg of thiol-purified excretory/secretory antigen along with montanide as adjuvant on day ۰, ۳۰ and ۶۰. On ELISA, it was observed that the mean absorbance values were significantly (p ≤ ۰.۰۱) higher up to ۲۰ weeks post immunization in Group-I (purified antigen) compared to Group- II (unimmunized control). Further, the mean EPG values was lower in Group I (۲۰۰.۰۰ ± ۴۰.۸۲ to ۴۰۰.۰۰ ± ۹۱.۲۹) than Group II (۲۲۰۰.۰۰ ± ۱۰۸.۰۱ to ۵۱۰۰.۰۰ ± ۱۶۹.۵۶) and the percentage reduction in mean fecal egg counts was ۸۸.۵۰%. Similarly, the mean abomasal worm counts was lower in Group I (۸۰۸.۳۳ ± ۷۸.۲۹) than Group II (۳۲۸۰.۰۰ ± ۱۴۷.۱۹) and the percentage reduction in mean abomasal worm count was ۷۵.۴۰%.

کلیدواژه ها:

Haemonchus contortus ، Excretory/secretory antigen ، Antibody ، Fecal egg count ، Sheep