Crystal Diagnostics Xpress™ E7 STEC Kit for the Rapid Multiplex Detection of E. coli O157 and non-O157 Shiga toxin-producing E. coli

The Crystal Diagnostics (CDx) Xpress E7 STEC kit is a rapid and sensitive detection assay for the detection of Escherichia coli 0157 and six non-0157 Shiga toxin-producing E. coli (serogroups 026, 045, 0103, 0111, 0121, and 0145, collectively referred to as STEC) at 1 CFU/325 g of raw ground beef and raw beef trim, or 200 g of spinach. The system comprises an automatic Crystal Diagnostics Xpress System Reader that integrates immunochemical and optical processes for the liquid crystal-based detection of microorganisms, a CDx BioCassette that incorporates antibody-coupled rnicrospheres and liquid crystal for selective identification of the intended microbe, and additional commercially available components. The Crystal Diagnostics Xpress System (TM) combines proprietary liquid crystal technology with antibody-coated paramagnetic microspheres to selectively capture and detect STEC from food matrixes. The Xpress System expeditiously (9.5 h enrichment) provides the sensitivity and specificity of the U.S. Department of Agriculture Food Safety and Inspection Service and the U.S. Food and Drug Administration reference methods in screening as low as 1 STEC CFU/test portion. The inclusivity validation demonstrated detection of 53 of 54 STEC test strains. Shelf life testing of the antibody-coated microspheres and other Crystal Diagnostic consumables indicated that all materials were stable for a minimum of 3 months (ongoing), and lot-to-lot testing demonstrated consistent results between lots (data not shown). The internal and independent laboratory tests demonstrate that the method is rapid and sensitive for screening of the target STEC.