Doctor of Philosophy (PhD)


Animal Science

Document Type



Brucella spp. are a bacterium that cause brucellosis, a zoonotic disease, which is commonly seen in cattle, sheep, goats, swine, and canines. Brucellosis is a problem worldwide, although it is eradicated in some countries (Garin-Bastuji et al. 1998). The reason for designing recombinant DNA (rDNA) vaccines opposed to utilizing the live-attenuated vaccines on the market is that they cannot be given to pregnant animals without potentially causing abortion, while an rDNA vaccine should be safe for pregnant animals since it does not contain viable bacteria. Also, there are no serological tests that can accurately distinguish between an animal vaccinated with the current vaccines available for brucellosis and an animal with an active Brucella infection because the current vaccines are live-attenuated and interfere with diagnostics. Recombinant DNA vaccines eliminate many safety concerns, which is why two rDNA vaccines were constructed in the same way, except for the length of the immunogenic epitopes selected from Brucella abortus. The epitopes from B. abortus that were chosen are present in the other main species of Brucella because the main species of Brucella, such as B. abortus, B. melitensis, and B. suis, are 99% identical at the DNA level. The epitopes range in length from 25 to 70 amino acids. Each vaccine contained a specific insert, with different lengths of epitopes and an antibiotic resistance gene that was incorporated for selection of successfully transfected cells during in vitro testing. After the vaccines were constructed, they were tested in vitro to determine the vaccine’s ability to enter different cell types and show protein expression in a variety of cells. The vaccines were tested in a caprine model to determine the vaccine’s ability to be successfully expressed in mammalian cells in vivo. It was determined that no significant antibody concentration was detected via the testing methods utilized.



Committee Chair

Cooper, Richard