1a.Objectives (from AD-416):
Explore and develop opportunities for control based on data identifying and characterizing routes of infection of Salmonella in the lymph nodes of cattle. Salmonella vaccine and chlorate will be evaluated to determine effectiveness in eliminating Salmonella from the lymph nodes following oral and dermal inoculation of dairy cattle.
1b.Approach (from AD-416):
Three studies will be conducted using dairy calves purchased and transported to our laboratory in College Station, TX. The first study will examine the duration and distribution of infection of Salmonella in several lymph nodes in calves receiving an SRP Salmonella vaccine. The second study will examine routes of exposure (oral or dermal) on Salmonella uptake and distribution by the lymph nodes. The final study will examine the effectiveness of sodium chlorate in eliminating Salmonella from the lymph nodes of previously infected calves.
This is a new project with the goal of establishing if Salmonella is acquired by the peripheral lymph nodes following intradermal exposure. Project work will evaluate the efficacy of different Salmonella vaccines in preventing uptake of Salmonella by peripheral lymph nodes following both dermal and oral exposure, and will determine if these same vaccines will eliminate Salmonella from the lymph nodes if administered post-Salmonella exposure. In FY 2012, studies were initiated to fully examine vaccine efficacy, and data obtained are being analyzed. Work by the project, as it continues, will develop important new information and technology that can be adapted to commercial beef production practices for enhancement of the microbial safety of beef products reaching the consumer.