Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #421188
Research Project: Analysis of Genetic Factors that Increase Foodborne Pathogen Fitness, Virulence, and Antimicrobial Resistance Transfer, to Identify Interventions against Salmonella and Campylobacter in Food Animals

Location: Food Safety and Enteric Pathogens Research

Title: Vaccination with the USDA BBS 866 Salmonella DIVA vaccine reduces intestinal colonization and systemic dissemination of DSC Salmonella enterica serovar Enteritidis in chickens

Author
item Bearson, Shawn
item Bearson, Bradley - Brad
item WHELAN, SAMUEL - Oak Ridge Institute For Science And Education (ORISE)
item ENCINOSA, MAYA - Oak Ridge Institute For Science And Education (ORISE)
item NEUPANE, DURGA - Oak Ridge Institute For Science And Education (ORISE)

Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 11/28/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Objective: Salmonella enterica serovar Enteritidis (Enteritidis) is one of the top Salmonella serotypes associated with human foodborne illness globally and is frequently linked to poultry. A strain of Enteritidis with decreased susceptibility to ciprofloxacin (DSC), a critical antibiotic prescribed for complicated human infections, has emerged in chickens. The purpose of the current study was to evaluate vaccination efficacy of the live, attenuated USDA BBS 866 DIVA vaccine for reduction of intestinal colonization and systemic dissemination of DSC Enteritidis in broiler chickens. Methods: One-day-old, commercial broiler chicks (n=44) housed in an ABLS2 isolation room at NADC were vaccinated via aerosol spray and booster vaccinated at two weeks of age via water administration (~3 x 108 colony forming units (CFU)/chick); a second room of 44 chicks was similarly administered PBS as the mock-vaccinated control group. At 5 weeks of age, all chickens were challenged via oral gavage with 1 x 109 CFU of DSC Enteritidis. At 7- and 14-days post-inoculation (dpi), chickens were randomly selected for euthanasia to collect cecum, spleen, and bone marrow tissues. Statistical analysis of qualitative and quantitative bacteriology for Salmonella was determined using Fisher’s exact test (prevalence) and an unpaired t test (colonization load), respectively. Results: Prevalence of DSC Enteritidis (i.e. +/-) was significantly decreased in vaccinated chickens for the cecum (14 dpi), spleen (7 and 14 dpi), and bone morrow (7 dpi) compared to mock-vaccinated chickens. For bone marrow, 5 of 13 (7 dpi) and 3 of 13 (14 dpi) mock-vaccinated chickens tested Salmonella-positive; bone marrow from all vaccinated chickens tested Salmonella-negative. Quantitative bacteriology revealed significant reduction in colonization levels of DSC Enteritidis in the vaccinated chickens at 7 and 14 dpi for the cecum (1.6-2.7 logs) and spleen (1.6-2.4 logs) compared to mock-vaccinated birds. CONCLUSIONS: Vaccination with the USDA BBS 866 Salmonella vaccine significantly reduced intestinal colonization and splenic dissemination as well as prevented dissemination to the bone marrow by DSC Enteritidis in broiler chickens, thereby providing a prospective intervention to reduce food product contamination.