Evaluation of 12 stabilizers in a developed attenuated Salmonella Enteritidis vaccine

The development of a stable live attenuated Salmonella Enteritidis (SE) vaccine, resisting heat stress during transportation and storage in unequipped tropical and subtropical zones of the world, is highly recommended. Twelve stabilizers were individually supplemented into a 9 ml volume of sterile distilled water resulting in concentrations of 1, 2, 3, 4 and 5%. A volume of 1 ml of attenuated live SE vaccine is added over the 9 ml of each concentration of the stabilizers. The differently stabilized SE vaccines were stressed at 55 degrees C for 48 h. The lowest percent reductions in SE cell viability by specified level of each stabilizer in ascending order were: 22.3% by 2% skim milk, 55.1% by 5% bovine serum albumin (BSA), 59.2% by 4% sorbitol, 74.4% by 3% maltose, 75% by 2% honey, 91.3% by 3% histidine, 96.9% by 1% heparin, 97.5% by 4% dextrose, 97.9% by 5% lactose, 99.4% by 5% sucrose, 99.5% by 2% gelatin, and 100% by 1-5% glycerol. In narrowing the concentration levels of skim milk to include 1.00, 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, and 3.00%, the 2.50% was the optimum level resulting in minimal percent reduction in SE cell viability of 18.9% after exposure to the defined heat stress.