title: Enzyme-linked immunosorbent assay for screening of milk samples for Salmonella typhimurium in dairy herds.
abstract: We investigated the ability of an antibody-specific, O antigen-based ELISA to document Salmonella typhimurium herd infections by screening of milk samples. Three cattle populations, 20 herds with no history of salmonellosis, 8 herds with history of S typhimurium episodes within the previous 7 months, and 220 herds of unknown disease status, were tested. A herd was considered ELISA positive if at least 5% of the cows had OD values > 0.3. Among the 20 herds without history of salmonellosis, only 2 herds were ELISA positive, whereas all 8 herds with a known history of salmonellosis were ELISA positive herd specificity, 0.9 and herd sensitivity, 1.0). A significant correlation (P < 0.001) was found between the OD values of serum and milk samples from cows in the herds with a history of salmonellosis. It was concluded that ELISA testing of individual milk samples can be used for surveillance of herds for S typhimurium infections, but further modifications are needed to test bulk tank milk samples.
authors.affiliation: Danish Veterinary Laboratory, Copenhagen, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Hoorfar
authors.forename: A
authors.initials: A
authors.lastname: Wedderkopp
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000276:immunology; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards / Q000662:veterinary*; D005260:Female; D008070:Lipopolysaccharides / Q000276:immunology; D008403:Mass Screening / Q000662:veterinary; D008892:Milk / Q000382:microbiology*; D019081:O Antigens / Q000032:analysis / Q000097:blood; D012481:Salmonella Infections, Animal / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control; D012486:Salmonella typhimurium / Q000276:immunology / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D008070:Lipopolysaccharides; D019081:O Antigens