الفهرس 
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Abstract
Aflatoxin M1 is one of mycotoxin derivatives, which is secreted in milk of dairy cattle fed on feed contaminated with Aflatoxin-B1 (AFB1). Following dairy cattle ingestion of AFB1 -contaminated feed, AFB1 is rapidly adsorbed and transported to the liver where it is partially metabolized into the hydroxy-derivate M1 (AFM1) that is secreted in milk. AFM1 is considered as toxic as AFB1 and has been included in group 2 toxins that are potentially carcinogenic for humans. The current study was designed to prepare a vaccine against AFB1 and to evaluate its efficacy in reducing or preventing secretion of AFM1 in milk. Aflatoxin-B1 was prepared, purified and transformed into oxime. Then it was fixed on bovine serum albumin as carrier molecules to become immunogenic. The AFB1-BSA conjugate was adjuvanted with Gold Nano particles (AFB1-BSA-GNPs) and Montanide ISA 206. The prepared AFB1-BSA-GNPs vaccine was used for immunization of rabbits and dairy cattle. In rabbits the vaccine was given S/C in a dose of 100µg/ml. In cattle the vaccine was given I/M in a dose of 500ug/2ml. The vaccinated animals were boosted with a second dose 3 weeks post primary immunization. The vaccinated and control rabbit groups were bled 2 weeks after primary vaccination and at 2, 4 and 6 weeks post booster vaccination. The collected serum samples were screened for the anti-AFB1-specific antibodies using agar gel precipitation test (AGPT). A mean titer of 15.2 Agar gel precipitation Unit (AGPU)/ml was detected at 2 weeks post vaccination. The Boosting vaccine doses induced significant increase in the anti-AFB1 specific antibodies that reached to 76.8 AGPU/ml at 6 weeks post booster vaccination. All vaccinated rabbits were challenged with 2 ml buffer containing 0.3 mg AFB1 toxin/Kg. The vaccinated rabbit group showed 100% protection and no AFB1 toxin residue was detected in their livers in comparison to the control non-immunized group. Milk and serum samples collected from AFB1-immunized dairy cattle and non-vaccinated controls were examined with ELISA for quantitation of AFM1 milk residues and in sera before and after vaccination. The prepared AFB1-BSA-GNPs vaccine was able to reduce Aflatoxin M1 release in milk and sera of vaccinated heifers by 70%, 81.9% respectively. The prepared AFB1-BSA-GNPs vaccine proved safe and potent. The vaccination of dairy cattle with the AFB1-vaccine might represent a valid tool for the prevention of AFM1 contamination of milk and dairy products.