Possibilities for standardization of ELISA for detection of Salmonella antibodies in sera and meat juices of pigs

• Published in: Berliner und Münchener tierärztliche Wochenschrift Vol. 113; no. 9; p. 331
• Main Authors: Steinbach, G, Staak, C, Bahn, P
• Format: Journal Article
• Language: German
• Published: Germany 01.09.2000
• Subjects: Animals; Antibodies, Bacterial - analysis; Antibodies, Bacterial - blood; Enzyme-Linked Immunosorbent Assay - standards; Enzyme-Linked Immunosorbent Assay - veterinary; Meat - microbiology; Salmonella Infections, Animal - blood; Salmonella Infections, Animal - diagnosis; Salmonella Infections, Animal - immunology; Salmonella typhimurium - immunology; Swine; Swine Diseases - blood; Swine Diseases - diagnosis; Swine Diseases - immunology
• ISSN: 0005-9366

Programmes for controlling salmonella infections in German piggeries are based on the meat-juice-ELISA conducted in various investigation centres by using different test-kits. A usual procedure for harmonization (standardisation) of results is the calculation of the percentage of antibody-concentration from field samples in relation to the extinctions of a set of control-sera with known antibody concentrations. Whether this system is still acceptable in case of using different test-kits seems to be questionable. In principle, difficulties arise by calculating field results from the regression curve of control-sera because the calculated percentages of antibodies do not represent the antibody concentration but, instead, the percentages of the extinctions measured, and secondly, because control-sera presently in use are directed against different salmonella serovars. In regard to the number of laboratories involved and because of a variety of test-kits used it seems to be more adequate to include only one anti-Salmonella Typhimurium standard-serum at a given antibody concentration which is to be tested repeatedly on every test-plate. Simultaneously, further controls should include another anti-Salmonella Typhimurium and one anti-Salmonella Choleraesuis serum which should provide results similar to the Danish system which is regarded as a standard. As well, a negative serum must be included in the test and a minimum difference in extinctions between this negative serum and the standard positive control-serum should be reached to prove the validity of results from the test plate.