02247nas a2200277   4500000000100000000000100001008004100002260007000043653001500113100001400128700001200142700001500154700001500169700001400184700001400198700001500212700001400227700001400241700001300255700001300268245012300281300001200404490000800416520153100424022001401955       2011                            d  c06/2011bSchlütersche Verlagsgesellschaft mbH & Co. KGaHannover10aSalmonella1 aU Roesler1 aI Szabo1 aC Matthies1 aK Albrecht1 aM Leffler1 aK Scherer1 aK Nöckler1 aJ Lehmann1 aU Methner1 aA Hensel1 aU Truyen00aComparing validation of four ELISAsystems for detection of  Salmonella  Derby- and S almonella  Infantis-infected pigs  a265-2710 v1243 aThe objective of this study was the comparative evaluation of four indirect Salmonella ELISA tests at study time approved in Germany to detect Salmonella infection in pigs. Three tests are based on a LPS-antigen mix and directed against specific IgG antibodies. The fourth test is based on a purified S. Typhimurium whole-cell lysate antigen and discriminates between Salmonella-specific IgM-, IgA-, and IgG- antibodies.  In a longitudinal study, two groups of six weeks old hybrid piglets were orally infected with a porcine S. Infantis or S. Derby strain. Clinical and bacteriological parameters were monitored weekly during an observation period of 130 days after infection and serum samples were investigated in parallel with the respective ELISAs.  Apparently, the LPS-based ELISA systems used in this study failed to recognize S. Infantis-infected pigs although those animals shed the pathogen in high amounts throughout the study until day 81 post infection (p. i.). In contrast, the isotype-specific Salmonella Typhimurium whole-cell-lysate based ELISA was capable of detecting Salmonella-infected pigs from day ten p. i. at all tested serotypes and revealed the highest sensitivity in detection of S. Infantis-infected pigs. Furthermore, it became apparent that the often used surveillance cut-off value of 40 OD% is not appropriate for intra-vitam detection of S. Infantis- and S. Derbyinfected pigs. In contrast, the cut-off values of the ELISAs given by the suppliers result in considerable higher detection rates.  a0005-9366