Prevention of egg contamination by Salmonella Enteritidis after oral vaccination of laying hens with Salmonella Enteritidis Δ tolC and Δ acrABacrEFmdtABC mutants

In this study, the efficacy ofSalmonella EnteritidisΔtolC andΔacrABacrEFmdtABC strains in laying hens as live vaccines was evaluated. The mutants are deficient in either the membrane channel TolC (ΔtolC) or the multi-drug efflux systems acrAB, acrEF and mdtABC (ΔacrABacrEFmdtABC). These strains have a decreased ability for gut and tissue colonization and are unable to survive in egg white, the latter preventing transmission of the vaccine strains to humans. Two groups of 30 laying hens were orally inoculated at day 1, 6  weeks and 16 weeks of age with 108 cfu of either vaccine strain, while a third group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 5 × 107 cfuSalmonella Enteritidis PT4 S1400/94. The vaccine strains were not shed or detected in the gut, internal organs or eggs, 2  weeks after the third vaccination. The strains significantly protected against gut and internal organ colonization, and completely prevented egg contamination bySalmonella Enteritidis under the conditions of this study. This indicates thatSalmonella EnteritidisΔtolC andΔacrABacrEFmdtABC strains might be valuable strains for vaccination of layers againstSalmonella Enteritidis.
Source: Veterinary Research - Category: Veterinary Research Source Type: research