Modified Immunodiffusion Method for Detection of Salmonella in Raw Flesh and Highly Contaminated Foods: Collaborative Study

A total of 19 government and private industry laboratories in Canada and the United States participated in the collaborative study. Naturally contaminated ground poultry and animal meals, as well as inoculated raw shrimp, were examined for presence of Salmonella by both the modified immunodiffusion method and the Bacteriological Analytical Manual culture method, resulting in an agreement rate of 93.1%. The 2 methods are statistically equivalent for all food types at each inoculation level and for all lots of naturally contaminated foods evaluated in this study. The modification of the AOAC Official Method 989.13, immunodiffusion (1-2 TEST) method for detection of motile Salmonella in all foods, has been adopted revised first action by AOAC INTERNATIONAL.