P3-48 Evaluation of the Atlas STEC Detection Assay for Fresh Raw Ground Beef and Fresh Raw Beef Trim

Wednesday, July 31, 2013
Exhibit Hall (Charlotte Convention Center)
Kristin Livezey, Roka Bioscience, San Diego, CA
Hua Yang, Roka Bioscience, San Diego, CA
Kathryn Baker, Roka Bioscience, San Diego, CA
Brett Maroni, Roka Bioscience, San Diego, CA
Kevin Tsao, Roka Bioscience, San Diego, CA
Apolonia Huerta, Roka Bioscience, San Diego, CA
Bettina Groschel, Roka Bioscience, San Diego, CA
Greg Merrick, Roka Bioscience, San Diego, CA
Jeff Panganiban, Roka Bioscience, San Diego, CA
Edgar Kamantigue, Roka Bioscience, San Diego, CA
Chad Fleischer, Roka Bioscience, San Diego, CA
Jarrod Morgan, Roka Bioscience, San Diego, CA
Michael Reshatoff, Roka Bioscience, San Diego, CA
Michele Wisniewski, Roka Bioscience, San Diego, CA
Michael Becker, Roka Bioscience, San Diego, CA
Introduction: Sensitive and specific detection methods are needed for the identification of pathogenic shiga-toxin producing Escherichia coli (STEC), including O157, O26, O45, O103, O111, O121, and O145 serotypes.

Purpose: To evaluate the Atlas STEC Detection Assay for the detection of E. coli O157:H7 and STECs in artificially inoculated ground beef and beef trim after a single enrichment of 375 g test portions.

Methods: The method included a single enrichment of 375 g test portions in modified Tryptic Soy Broth (mTSB) at 42°C. After sample transfer for bacterial lysis, template specific sample extraction, amplification and probe detection were all performed on the automated instrument. Fresh raw ground beef, 30% fat, and fresh raw beef trim were compared to the FSIS MLG 5.06 and 5B.02 confirmation procedures. Selectivity was evaluated by testing 50 target microorganisms and 30 non-target microorganisms as determined by POD analysis.

Results: The test method provided a positive result for 100% of 50 target microorganisms, and a negative result for 30 non-target microorganisms. No significant differences were observed between the test method and the FSIS MLG 5.06 and 5B.02 confirmation methods.

Significance: E. coli O157:H7 and STEC, including the FSIS regulated big six serogroups, can be detected in raw ground beef and beef trim on the Atlas System.