The detection of Salmonella using a combined immunomagnetic separation andELISA end-detection procedure

The aim of this study was to develop a rapid immunoassay to detect Salmonel la bacteria. Skimmed milk powder (SMP) in buffered peptone water was inocul ated with six Salmonella strains (Salm. typhimurium, Salm. virchow, Salm. e nteritidis, Salm. give, Salm. ealing and Salm. arizonae) at three inoculum levels (about 2-200 cfu 25 g(-1) SMP) and incubated (37 degreesC) overnight . Heat-treated salmonella cells were immobilized on paramagnetic particles and detected within 3 h using the Salmonella genus-specific monoclonal anti body M105 in a microtitre plate based assay. The rapid Salmonella detection method combining immunomagnetic separation and ELISA bad a total isolation and detection time of less than 24 h, which is significantly shorter than the conventional techniques requiring 72-96 h. The technique had a sensitiv ity limit of 10(5)-10(6) cfu ml(-1).