Enzyme-linked immunosorbent assay for Salmonella typhimurium in food: feasibility of 1-day Salmonella detection

A microtitration plate, antibody-capture, enzyme-linked immunosorbent assay was developed for detection of Salmonella typhimurium. The assay utilizes a monoclonal detector antibody which shows no cross-reactions with non-Salmonella species and only a slight cross-reaction with one other Salmonella serotype. By using only one cultural stage (in a nonselective, chemically defined medium) prior to the enzyme-linked immunosorbent assay, low numbers of cells in food (10 cells 25 g-1) were detected in 19 h. Non-Salmonella competing organisms did not interfere with detection of S. typhimurium even when present in the ratio of 10(6):1 (non-Salmonella/Salmonella spp.). The assay shows the feasibility of rapid, 1-day testing for Salmonella spp. with antibody technology.