|Bearson, Bradley - Brad|
|Kogut, Michael - Mike|
Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2018
Publication Date: 2/1/2019
Citation: Bearson, S.M., Bearson, B.L., Sylte, M.J., Looft, T.P., Kogut, M.H., Cai, G. 2019. Cross-protective Salmonella vaccine reduces cecal and splenic colonization of multidrug-resistant Salmonella enterica serovar Heidelberg. Vaccine. 37(10):1255-1259. https://doi.org/10.1016/j.vaccine.2018.12.058.
Interpretive Summary: Salmonella is a leading cause of human foodborne disease, and an estimated 17 percent of human infections with Salmonella in the U.S. are attributed to the consumption of contaminated turkey. In 2011, a foodborne illness outbreak due to multidrug-resistant Salmonella enterica serovar Heidelberg from ground turkey sickened 136 individuals (1 death) and resulted in the recall of 36 million pounds of ground turkey. To reduce the entrance of Salmonella into the human food chain, pre-harvest interventions such as vaccines are needed to reduce human foodborne pathogens in food animals. In the current study, we evaluated a live, attenuated Salmonella enterica serovar Typhimurium oral vaccine recently created by our research group for use in food animals. Vaccinated turkeys that were subsequently challenged with the Salmonella Heidelberg outbreak strain had significantly less colonization of the Heidelberg strain in their intestinal tract as well as reduced systemic dissemination of Heidelberg to the spleen compared to non-vaccinated turkeys. This study demonstrates an efficacy of the Salmonella vaccine for reduction of MDR Salmonella Heidelberg colonization in turkeys that could limit foodborne outbreaks and product losses due to recalls.
Technical Abstract: Salmonella vaccine strategies for food-producing animals have typically focused on a specific serovar that either causes production losses due to morbidity/mortality or is an important food safety pathogen for a particular food commodity. The Salmonella enterica serovar Typhimurium BBS 866 vaccine strain was designed to reduce serovar specificity to provide cross-protection against diverse Salmonella serovars, thereby broadening its applicability for multiple animal and poultry species. We reported cross-protection of the BBS 866 vaccine in swine [Vaccine 34:1241-6]. In the current study, we extend the efficacy of the Salmonella vaccine to a poultry commodity by revealing significant reduction of multidrug-resistant Salmonella enterica serovar Heidelberg colonization of the cecum and systemic dissemination to the spleen in BBS 866-vaccinated turkeys. Transcriptional analysis of whole blood from BBS-vaccinated turkeys revealed down-regulation of metabolic and immune genes (KCNAB1, ACOD1, GPR17, ADOR2AB, and IL-17RD), suggesting limited leukocyte activation without an overt peripheral inflammatory response to vaccination.