LOCATE enzyme-linked immunosorbent assay for detection of Salmonella in food: collaborative study

A collaborative study was performed in 27 laboratories to validate the enzyme-linked immunosorbent procedure LOCATE for rapid detection of Salmonella in foods. Results were read visually and with a microtiter plate reader. The LOCATE method was compared with the Bacteriological Analytical Manual (BAM)/AOAC INTERNATIONAL culture method for detecting Salmonella in 6 foods: milk chocolate, nonfat dry milk, dried whole egg, soy flour, ground black pepper, and ground raw turkey. Two foods--dried whole egg and black pepper--required repeat rounds because insufficient data sets were produced initially (AOAC INTERNATIONAL stipulates a minimum of 15 sets per food type). Each laboratory tested one or more of the 6 foods. A total of 1 439 samples were analyzed, and no significant differences (P < 0.05) were observed between LOCATE with either visual or reader detection and BAM/AOAC INTERNATIONAL results. The LOCATE screening method with visual or reader detection is recommended for Official First Action Approval.