title: Vaccination of calves with orally administered aromatic-dependent Salmonella dublin.
abstract: Genetically altered stable nonreverting aromatic-dependent (aro-) Salmonella dublin, strain SL5631, was administered orally to healthy colostrum-fed calves as vaccine. Twenty-six calves were allotted to 4 groups. There were 2 experiments, each with a vaccinated and nonvaccinated control group. Skin testing with 0.1 ml of sonicated S dublin was performed 3 days prior to challenge exposure. The IgG and IgM titers to S dublin lipopolysaccharide (LPS) antigen were determined by ELISA on sera before initial vaccination and at 1.5 to 2 weeks after each vaccination. In experiment 1, six calves received a dose of 1.7 x 10(10) colony-forming units (CFU) of aro-S dublin SL5631 orally at 2 and 4 weeks of age. After the first vaccination, 2 of 6 calves developed fever, but all 6 calves continued to have normal appetite and mental attitude. Adverse changes were not observed after the second vaccination. At the time of challenge exposure at 6 weeks of age, all 12 calves were seronegative for IgG and IgM LPS-specific antibodies, and the difference in percentage increase in skin test reaction at 48 hours was not significant. At 6 weeks of age, the 6 vaccinates and 6 controls were orally challenge-exposed with 1.5 x 10(11) CFU of virulent S dublin T2340. Protection from challenge was not evident, as 3 of 6 controls and 5 of 6 vaccinates died after challenge exposure. In experiment 2, eight calves received a dose of 5 x 10(11) CFU of aro-S dublin SL5631 orally at 2, 3.5, and 5 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616.
authors.forename: B P
authors.initials: BP
authors.lastname: Smith
authors.forename: G W
authors.initials: GW
authors.lastname: Dilling
authors.forename: L
authors.initials: L
authors.lastname: Da Roden
authors.forename: B A
authors.initials: BA
authors.lastname: Stocker
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001428:Bacterial Vaccines / Q000276:immunology*; D002417:Cattle / Q000276:immunology*; D002418:Cattle Diseases / Q000382:microbiology / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D008297:Male; D012475:Salmonella / Q000235:genetics / Q000276:immunology*; D012481:Salmonella Infections, Animal / Q000401:mortality / Q000517:prevention & control; D012882:Skin Tests / Q000662:veterinary; D014613:Vaccines, Attenuated / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D014613:Vaccines, Attenuated