title: Evaluation of protection against experimental salmonellosis in sheep immunised with 1 or 2 doses of live aromatic-dependent Salmonella typhimurium.
abstract: The minimum number of doses of a live aromatic dependent (aro-) Salmonella typhimurium vaccine strain (SL1479), given by the intramuscular, oral or subcutaneous route required to protect sheep from experimentally-induced clinical salmonellosis, was determined. A significant reduction in mortalities and diarrhoea occurred in those sheep immunised with one or 2 intramuscular doses or 2 subcutaneous doses. On the other hand, sheep immunised with one subcutaneous dose were not protected. Immunisation with one or 2 oral doses also resulted in a significant reduction in mortality, although reduction in the prevalence of severe diarrhoea was less consistent. Sheep immunised with a single intramuscular dose of aro- S. typhimurium developed high levels of serum antibodies and significant delayed-type cutaneous hypersensitivity response to homologous Salmonella lipopolysaccharide and flagellin, whereas those with a single oral dose did not. It was concluded that immunisation of sheep with a single oral or intramuscular dose of live aro- S. typhimurium reduced mortalities and the prevalence of diarrhoea in sheep due to infection with virulent S. typhimurium.
authors.affiliation: Department of Veterinary Pathology, University of Sydney, New South Wales.
authors.forename: A P
authors.initials: AP
authors.lastname: Begg
authors.forename: K H
authors.initials: KH
authors.lastname: Walker
authors.forename: D N
authors.initials: DN
authors.lastname: Love
authors.forename: T K
authors.initials: TK
authors.lastname: Mukkur
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D003967:Diarrhea / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D006968:Hypersensitivity, Delayed; D007114:Immunization / Q000662:veterinary; D007273:Injections, Intramuscular / Q000662:veterinary; D007279:Injections, Subcutaneous / Q000662:veterinary; D008297:Male; D012481:Salmonella Infections, Animal / Q000517:prevention & control*; D012486:Salmonella typhimurium / Q000276:immunology*; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines