Reduction of Salmonella in Cattle Feces and On Cattle Hides

Approach: Vaccine: A small number of MARC cattle (n = 10 to 20) will be vaccinated systemically as per manufacturer's instructions with a commercially available and USDA-licensed anti-Salmonella Newport vaccine. A similar number of cattle (n = 10 to 20) will be sham-vaccinated with PBS. Following adequate time (approximately one month) for development of a vaccine-induced systemic and mucosal immune response, sera and small and large intestinal tissue full thickness (serosa-to-mucosa) biopsies will be surgically harvested from both vaccinated and non-vaccinated cattle under local standing anesthesia or inhalation anesthesia, as appropriate. The biopsied tissues will be placed in Ussing chambers and challenged with multiple strains of MDR and non-MDR Salmonella Newport and Salmonella Typhimurium DT104. Outcomes measures will include Salmonella mucosal adherence, Salmonella mucosal invasion, and Salmonella-specific immune exclusion via secretory IgA. <P> Hide Survival: Cattle from multiple pens at the MARC feedlot will be screened for colonization by Salmonella. Animals from pens with a high prevalence of Salmonella will be randomly sorted into two groups. One group will stay in the feedlot while the other group will be isolated in individual pens. The hides and feces of both groups will be periodically sampled to determine the presence of Salmonella. Salmonella isolates will be genotyped using pulsed field gel electrophoresis. If multiple species are present, they will be screened for multidrug-resistance to identify if MDR has any effect on survival time.

<P> For complete projects details, view the <a href="http://www.beefresearch.org/CMDocs/BeefResearch/Reduction%20of%20Salmon…; target="_blank">Project Summary. </a>