Rapid tests for microbial detection in food processing on the market today provide information on the presence or absence of specific pathogens after an enrichment process of 24 to 48 hours. Our method will utilize immunomagnetic separation after brief enrichment (<7 hours) using specific antibodies for each of these three pathogens to isolate and concentrate the bacteria from the food matrix (meat or surface debris). This clean sample will then be treated with a general DNA specific fluorochrome for cytometric detection. This method will be interfaced with a specialized flow cytometer (RBD2000) designed to provide accurate and low level detection of these fluorescent signals. Verification of the presence of each pathogen will be confirmed based upon comparison of cytometric detection with traditional plating techniques. The integration of capture, labeling and counting methodology will provide a fast and accurate presence/absence detection test for Listeria and Salmonella in poultry wash and Listeria, Salmonella and E. coli O157:H7 in carcass and plant surface samples.
Anticipated Results/Potential Commercial Applications of Research: The annual U.S. market for testing of specific pathogenic organisms was estimated to encompass 15 million tests during 2000. In comparison to other rapid technologies (PCR and antibody-based assays) on the market requiring long enrichment (24-48h), the development of these assays will provide faster turnaround times from sampling to answer for the detection of Listeria, Salmonella and E. coli O157:H7 pathogen presence or absence on food processing surfaces testing, in poultry wash and carcass swabs. These assays will have market potential to meat and food processing plants which average approximately 3,500 pathogen tests annually for each plant.
