PROBLEM TO BE SOLVED: To solve problems needing much labor and long time for investigating Escherichia coli colonies at all possible spots as contamination sources at a point when such Escherichia coli colonies are newly detected from food, despite the fact that urgent specification of such a contamination source is required for the inspections, in view of the fact that various spots in food production process may represent contamination sources for Escherichia coli colonies. SOLUTION: A method for specifying contamination source(s) for Escherichia coli colonies is provided, comprising the following procedure: The constitutional results of classifying, based on selective media, Escherichia coli colonies gathered from respective spots including raw materials, water, various kinds of equipment, the atmosphere, relevant operators/workers, animals/insects and structures such as floors, each representing the contamination sources of Escherichia coli colonies in a food production plant, are made into database by relating the results to the above spots. While, the constitutional results of the Escherichia coli colonies newly detected from the food in the food production plant are classified based on the above media, and the latter constitutional results are compared with the former ones as the database, and when both of them are the same as each other or fall within a predetermined error range, the above spots are decided as contamination sources. COPYRIGHT: (C)2007,JPO&INPIT
