Begg A P, Walker K H, Love D N, Mukkur T K
Department of Veterinary Pathology, University of Sydney, New South Wales.
Aust Vet J. 1990 Aug;67(8):294-8. doi: 10.1111/j.1751-0813.1990.tb07800.x.
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.
