Abstract
Vaccination of hens with Salmonella enteritidis(SE) bacterin has become an important industry management tool to reduce both the incidence of SE in flocks and the production of SE-contaminated eggs. After vaccination, antibodies to SE can be found in both the serum and egg yolks. The current study was undertaken to examine whether the antibodies deposited in eggs after vaccination would have any effect on the in vitrogrowth of 10 SE seeded into pooled egg contents and incubated at 37°C for 24 h. The SE inoculum grew well in egg contents from control-vaccinated hens, and a high percentage of these samples were culture positive for SE. Conversely, significantly fewer egg contents from vaccinated hens were positive for SE at weeks 2, 3, 4, and 5 post-primary vaccination and weeks 1, 2, and 4 post-secondary vaccination. After 24 h incubation, the SE inoculum grew to 10 8–10 9organisms ml −1in egg contents from control hens, while growing to less than 10 4organisms ml −1in egg contents from vaccinated hens. No inhibition of growth was observed for a second organism, Proteus mirabilis, in egg contents from bacterin-vaccinated hens, indicating antigen-specificity of the activity. Inhibition of SE growth was observed in egg contents from vaccinated hens diluted 1:5 in eggs from control hens. Mixed results were observed for egg contents receiving a 10-fold higher SE inoculum with significant inhibition of growth observed in one trial and minimal inhibition observed in a second trial. Supplementing the egg samples with an iron source abrogated the inhibition, suggesting that the iron- restricted environment found in eggs may play a role in the observed inhibition.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.