The AOAC Research Institute (AOAC-RI) has granted a method extension for the DuPont™ BAX® System real-time polymerase chain reaction (PCR) assays for Listeria to include validation of a new proprietary enrichment media. This method can return Listeria results in just 22 hours for some matrices--one of the fastest time-to-results available for the pathogen in the food safety industry today.

The AOAC-RI method allows customers to perform a single-stage, 20-26 hour enrichment (sample-dependent) in FoodChek™ Actero™ Listeria Enrichment Media, followed by rapid real-time processing with the DuPont™ BAX® System. The extension includes detection of both Listeria species (AOAC-RI Performance Tested MethodSM #081401) and L. monocytogenes (AOAC-RI Performance Tested MethodSM #121402) and has been tested in frankfurters, shrimp, smoked salmon, spinach and queso fresco, as well as on stainless steel, plastic and sealed concrete surfaces.

“The biggest advantage of this combined testing method is the reduced enrichment time, without the need for a secondary enrichment protocol,” says Morgan Wallace, DuPont Nutrition & Health senior microbiologist and validations leader for diagnostics. “Listeria is a slow-growing pathogen, so any steps that allow for faster detection are important to the food safety industry and help provide cost-saving benefits to customers.”

“Enriching food samples in Actero™ Listeria Enrichment media allows laboratories to use about 33 percent less media per sample than other methods,” says FoodChek™ chairman, president and CEO William J. Hogan. “This not only results in less waste disposal during the testing process, but also helps improve the financial bottom line for food companies and commercial testing laboratories alike.”

The DuPont™ BAX® System provides advanced, automated testing for foodborne pathogens, spoilage organisms and other microbes in raw ingredients, finished products and manufacturing environments. The system breaks down samples at the genetic level using the power of the PCR, then uses target-specific primers to automatically detect the presence or absence of the target bacterial DNA and provide clear yes-or-no results. With certifications and regulatory approvals around the world, the BAX® System is recognized as one of the most advanced pathogen testing systems available to the food industry today.