Comparison of a live attenuated Salmonella Enteritidis vaccine candidate secreting Escherichia coli heat-labile enterotoxin B subunit with a commercial vaccine for efficacy of protection against internal egg contamination by Salmonella in hens.

Abstract

This study compared a new live attenuated Salmonella Enteritidis vaccine candidate secreting Escherichia coli heat-labile enterotoxin B subunit (SE-LTB) with a commercial Salmonella Enteritidis (SE) vaccine for efficacy of protection against SE infection in laying hens. Chickens were divided into 3 groups of 20 each. Group A chickens were inoculated orally with phosphate-buffered saline and served as controls, group B chickens were inoculated orally with the vaccine candidate, and group C chickens were inoculated intramuscularly with a commercial vaccine, the primary inoculation in groups B and C being at 10 wk of age and the booster at 16 wk. Groups B and C showed significantly higher titers of plasma immunoglobulin G, intestinal secretory immunoglobulin A, and egg yolk immunoglobulin Y antibodies compared with the control group, and both vaccinated groups showed a significantly elevated cellular immune response. After virulent challenge, group B had significantly lower production of thin-shelled and/or malformed eggs and a significantly lower rate of SE contamination of eggs compared with the control group. Furthermore, the challenge strain was detected significantly less in all of the examined organs of group B compared with the control group. Group C had lower gross lesion scores only in the spleen and had lower bacterial counts only in the spleen, ceca, and ovary. These findings indicate that vaccination with the SE-LTB vaccine candidate can efficiently reduce internal egg and internal organ contamination by Salmonella and has advantages over the commercial vaccine.

• Authors: Rahul M Nandre, Seong Kug Eo, Sang Youel Park, John Hwa Lee
• Journal: Canadian journal of veterinary research = Revue canadienne de recherche veterinaire (Can J Vet Res) Vol. 79 Issue 3 Pg. 235-40 (Jul 2015) ISSN: 1928-9022 [Electronic] Canada
• PMID: 26130857 (Publication Type: Controlled Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bacterial Toxins
• Bacterial Vaccines
• Enterotoxins
• Escherichia coli Proteins
• heat-labile enterotoxin, E coli

Topics

• Animals
• Bacterial Toxins (genetics, metabolism)
• Bacterial Vaccines (immunology)
• Chickens
• Eggs (microbiology)
• Enterotoxins (genetics, metabolism)
• Escherichia coli Proteins (genetics, metabolism)
• Female
• Food Microbiology
• Poultry Diseases (prevention & control)
• Salmonella Infections, Animal (microbiology, prevention & control)
• Salmonella enteritidis (metabolism)