title: 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.affiliation: Department of Bioactive Material Sciences, and Department of Veterinary Public Health College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Rahul M
authors.initials: RM
authors.lastname: Nandre
authors.affiliation: Department of Bioactive Material Sciences, and Department of Veterinary Public Health College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Seong Kug
authors.initials: SK
authors.lastname: Eo
authors.affiliation: Department of Bioactive Material Sciences, and Department of Veterinary Public Health College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Sang Youel
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Bioactive Material Sciences, and Department of Veterinary Public Health College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: John Hwa
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism*; D001428:Bacterial Vaccines / Q000276:immunology*; D002645:Chickens; D004531:Eggs / Q000382:microbiology*; D004768:Enterotoxins / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005516:Food Microbiology; D011201:Poultry Diseases / Q000517:prevention & control*; D012481:Salmonella Infections, Animal / Q000382:microbiology / Q000517:prevention & control*; D012477:Salmonella enteritidis / Q000378:metabolism*
chemical_list: D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C027538:heat-labile enterotoxin, E coli