الفهرس | Only 14 pages are availabe for public view |
Abstract Pulpy kidney disease caused by C. perfringens type D which secret epsilon toxin cause sudden death, diarrhea and nervous manifestation result in great economical and sanitary importance for cattle, sheep and goat. The vaccination against pulpy kidney disease depends mainly on epsilon toxoid. Some factors affecting the release of epsilon toxin were studied. It was found that using TGY media at pH 8.5 at 42ºC was optimal for bacterial growth and at 33ºC for maximal toxin yield with incubation for 48 hours. It was also found that the combination between trypsin and traces of chymotrypsin at pH 7.2 for 45 minutes incubation at 37ºC was economical and more effective for activation of epsilon protoxin. The using of chitosan as an adjuvant for the vaccine give higher immune response in vaccinated animals than that vaccinated with alum precipitated one. Finally the results revealed great variation in immune response between prepared vaccines in comparison to the current routinely used vaccine. So we recommend replacement of formulation of routine vaccine by the prepared one. |