title: Detection of antibodies to Salmonella lipopolysaccharide in muscle fluid from cattle.
abstract: OBJECTIVE
  To compare muscle fluid with serum samples for detection of antibodies to Salmonella lipopolysaccharide.
  
  
  METHODS
  Muscle fluid and serum samples from 2 cattle populations: 1 from the island of Bornholm with no history of salmonellosis (n = 39), and the other from the S dublin-enzootic areas of Jutland (n = 144).
  
  
  METHODS
  Salmonella dublin (O:1,9,12), S typhimurium (O:1,4,5,12), and Salmonella O:9-blocking ELISA were used for testing the samples.
  
  
  RESULTS
  In the S dublin ELISA, all serum and muscle fluid samples from cattle on the island of Bornholm had OD450 values well below the cutoff value (0.5). For samples obtained from cattle in the enzootic areas of Jutland, high correlation was found between serum and muscle fluid samples (rs = 0.89, P < 0.001). In addition, 19% (28/144) of the cattle had ELISA-positive muscle fluid and serum samples; 2% (3/144) had positive results for muscle fluid only, whereas 1 animal had positive results for serum only (kappa = 0.91, P < 0.0001; sensitivity and specificity of 97%). The same samples had similar significant correlation in the S typhimurium ELISA (rs = 0.88, P < 0.001, kappa = 0.7, P < 0.001; sensitivity of 73% and specificity of 98%) and the O:9-blocking ELISA (rs = 0.49, P < 0.001).
  
  
  CONCLUSIONS
  Muscle fluid samples taken at slaughter can be used as a practical alternative to serum samples for surveillance of Salmonella infections in cattle.
authors.affiliation: Danish Veterinary Laboratory (Hoorfar, Lind), Copenhagen V, Broerup, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Hoorfar
authors.forename: A
authors.initials: A
authors.lastname: Wedderkopp
authors.forename: P
authors.initials: P
authors.lastname: Lind
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis* / Q000097:blood; D002417:Cattle / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D002418:Cattle Diseases / Q000453:epidemiology / Q000276:immunology; D003718:Denmark / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D008070:Lipopolysaccharides / Q000276:immunology*; D018482:Muscle, Skeletal / Q000276:immunology*; D012475:Salmonella / Q000276:immunology*; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D008070:Lipopolysaccharides