Trials for Production of Aflatoxin Free Milk Through Immunization of the Dairy Cattle by Aflatoxin B1- Vaccine

Abstract

Aflatoxins are considered among of the most important problems that cause serious health hazard to human, birds and pet and farm animals. Aflatoxicosis in dairy cattle is associated with serious increase in the percentage of AFM1 contamination in the milk and dairy products for human consumption. The present study was designed to produce aflatoxin M1 free milk through development and immunization of the dairy cattle with aflatoxin B1 vaccine. It is assumed that the AFB1 vaccine will stimulate the production of AFB1-specific antibodies. These antibodies could prevent or reduce Aflatoxin B1 residue in liver which in turn lead to decrease Aflatoxin M1 excretion in dairy milk. The research plan includes preparation of AFB1, which was conducted by growing an aflatoxin-B1 producing A. flavus strain on special media, followed by extraction and purification of AFB1 toxin. Since AFB1, has no reactive group for coupling reactions, it was first converted to AF- B1-O-carboxymethyl oxime (AFB1-Oxime). The AFB1 was then conjugated on bovine serum albumin (BSA) as a carrier molecule. The prepared AFB1-BSA conjugate was further adjuvanted with gold nanoparticles and Montanide ISA 206. The immunizing efficacy of the prepared AFB1vaccine was tested in rabbits and dairy cattle. Bosket Rabbits were vaccinated subcutaneously with the prepared AFB1-BSA-GNPs vaccine using 100µg/dose. The immunized rabbits received two doses at 3 weeks interval. The immunized and control non immunized rabbits were bled 2 weeks post 1st immunization and at 2, 4, 6 weeks after the booster dose. The collected serum was tested for detection of AFB1 specific antibodies using AGPT. In vaccinated rabbits mean AFB1 specific antibodies titers of 15.2, 41.6, 70.4 and 76.8 AGPU/ml were measured at 2WPV, 2WPB, 4WPB and 6WPB, respectively. The control non vaccinated group