Transcriptome responses to Salmonella enterica serovar Reading in vaccinated and unvaccinated turkeys

The 2017-2019 foodborne outbreak of Salmonella enterica serovar Reading (S. Reading) in North America revealed the need for effective control of this serovar in turkey production. This study evaluated two live-attenuated Salmonella vaccines against an outbreak-associated strain of S. Reading in turkeys. At 1 day and 3 weeks of age, male turkey poults were either mock-vaccinated or given either an internally developed cross-protective vaccine and a commercially available vaccine. At 7 weeks of age, poults were challenged with S. Reading; one mock-vaccinated group was mock-challenged. Along with assessment of Salmonella colonization and dissemination, acute transcriptomic responses in the cecal tonsil were characterized at 2 days post inoculation and revealed decreased expression of genes encoding intestinal transporters and tight junction proteins. Vaccination with either vaccine mitigated most of the transcriptional changes in intestinal health-related genes induced by S. Reading in turkey cecal tonsil.