title: Immunoassays to detect the serum antibody response of cattle to infection with Salmonella Typhimurium definitive type 104 and following vaccination with Bovivac S.
abstract: OBJECTIVE
  To use ELISA and immunoblotting assays to examine the serum antibody response of cattle infected with Salmonella Typhimurium DT104 and following vaccination with Bovivac S.
  
  
  RESULTS
  Three hundred and twenty-nine cattle, including 16 shedding multiresistant Salmonella Typhimurium DT104, were screened for serum antibodies binding to O=1, 4, 5, 12 lipopolysaccharide (LPS) antigens before and after vaccination with Bovivac S. Sera with an ELISA reading of 0.9A405 or above were shown to contain antibodies, of the IgG-class only, to the LPS of Salmonella Typhimurium using immunoblotting. Prior to vaccination, only 11 cattle had serum IgG-class antibodies to the O=4, 5 LPS antigens, and of these one also had antibodies to outer membrane proteins and H=i flagellar antigens. Following vaccination, 87 out of 315 cattle developed serum antibodies to the LPS of Salmonella Typhimurium.
  
  
  CONCLUSIONS
  Evidence of infection of cattle with Salmonella Typhimurium was readily obtained with an LPS-based ELISA in association with an immunoblotting procedure, supplementing existing bacteriological procedures. This enabled the detection of an increase in the number of cattle with serum antibodies to Salmonella Typhimurium LPS following vaccination with Bovivac S.
  
  
  CONCLUSIONS
  The immunoassays described provided evidence of infection with Salmonella Typhimurium and served as a valuable adjunct to established bacteriology.
authors.affiliation: Laboratory of Enteric Pathogens, Division of Gastrointestinal Infections, Central Public Health Laboratory, London, UK. hchart@phl.co.uk
authors.forename: H
authors.initials: H
authors.lastname: Chart
authors.forename: M C
authors.initials: MC
authors.lastname: Pearce
authors.forename: D
authors.initials: D
authors.lastname: Mellor
authors.forename: D J
authors.initials: DJ
authors.lastname: Shaw
authors.forename: D
authors.initials: D
authors.lastname: Brown
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001428:Bacterial Vaccines / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000517:prevention & control*; D007118:Immunoassay / Q000379:methods*; D012481:Salmonella Infections, Animal / Q000276:immunology / Q000517:prevention & control*; D012486:Salmonella typhimurium / Q000145:classification / Q000276:immunology*; D012703:Serotyping
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines