DEOXYRIBONUCLEIC-ACID HYBRIDIZATION METHOD FOR THE DETECTION OF LISTERIA IN DAIRY-PRODUCTS, SEAFOODS, AND MEATS - COLLABORATIVE STUDY

The method is based on the hybridization of synthetic deoxyribonucleic acid probes to ribosomal ribonucleic acid sequences unique to Listeri a. This method was compared to 2 culture methods: the U.S. Food and Dr ug Administration method for the detection of Listeria in dairy produc ts and seafoods and the U.S. Department of Agriculture, Food Safety an d Inspection Service method for Listeria in meats. Six food types with replicate samples containing various concentrations of Listeria were analyzed by the collaborating laboratories. Listeria was detected in 7 74 samples using the DNAH method and in 772 samples using a culture me thod. The DNAH and culture methods were in agreement for 668 samples c ontaining Listeria and 306 samples without Listeria. The overall rate of agreement between methods was 82.3%. The method has been adopted fi rst action by AOAC INTERNATIONAL.