CONTINUING STUDIES ON BIOMEDICAL COUNTERMEASURES AGAINST BRUCELLOSIS IN DOMESTIC AND WILD HOSTS....

(WYO-00614)

The disease produced by B. abortus in domestic livestock can be potentially devastating, thus substantiating the need for a continuing effort to development more effective vaccines. We have identified three potential new vaccine candidates, which unlike the current brucellosis vaccines on the market, are non-living. Despite demonstrating some success our candidates in a mouse model, adequate large animal models must be established to effectively test candidates against the disease in ruminants. The goat has been well characterized over 20 years ago by experimental Brucella infection, producing the same disease processes as in cattle. Thus, the goat has been proposed as a suitable model for the study of brucellosis in cattle, and is well-suited for vaccine studies. The first part of our project thus represents the evaluation of a three vaccine candidates for their ability to protect against brucellosis using the goat model. The utility of goats as a ruminant model for brucellosis includes lower cost, more manageable logistics, and a gestation period of just 150 days. If we are successful, our study in the goat may yield an effective and safe new vaccine against brucellosis. Despite a long history of infection of humans and livestock by Brucella, relatively little is known of the specific bacterial disease factors that contribute to interactions with susceptible animals. Analysis of Brucella genes have revealed only about a dozen relevant factors suggesting that many more factors remain to be discovered. Therefore, a functional screen of Brucella genes also will be conducted in parallel with the evaluation of already identified gene products in the goat. The outcome of this study may result in new vaccine candidates. Finally, although the efficacy of existing brucellosis vaccines has been well documented , little effort has been made to estimate the economic benefit of a more effective brucellosis vaccine. We will therefore calculate the benefit of how an improved vaccine would affect cattle producers' willingness to practice adult animal booster vaccination. As an outcome, we propose that an increase in the vaccine's effectiveness would induce more producers to practice such vaccination.

USDA CRIS Project Information Link: 0221622