STEC DETECTION SOLUTIONS: A FLEXIBLE APPROACH
Assurance GDS® combines the latest advancements in immunomagnetic separation (IMS), molecular technology, and food microbiology to provide a collection of methods for the detection of the major non-O157 serotypes of Shiga Toxigenic E. coli (STEC).
With several different STEC assays to choose from, no matter which direction the next EU Commission guidance recommends, it will be possible to quickly adjust testing to meet the new regulation.
Unparalleled Test Flexibility
There are several testing options now available, aligned with the Karmali approach, which include detection of both Shiga Toxin genes (stx1, stx2) and the eae virulence marker. An additional virulence marker for the Enteroaggregative family (aggC) has been included in a separate E. coli O104 assay in case the EFSA opinion is followed. Assurance GDS incorporates a proprietary PickPen® IMS sample preparation procedure, which captures and isolates STEC belonging to the target serogroups (O26, O45, O103, O111, O121, O145 and E. coli O157:H7), prior to detection of the gene targets. As a result, target gene detection is performed on a subset of organisms belonging only to the serogroups of concern, drastically reducing the amount of false positive results typically found with STEC testing.
- Assurance GDS MPX Top 7 STEC provides results in 12 hours for both Top 6 non-O157 STEC and E. coli O157:H7 from a single enriched sample
- Assurance GDS MPX ID – a secondary screening assay for GDS MPX that discriminates the presence of pathogenicity targets from a single organism vs multiple organisms containing only one of the markers
- Assurance GDS Top 7 (eae) method, which follows the ISO 13136 multi-step molecular design, allows for the sequential analysis of the Top 6 non-O157 STEC and E. coli O157:H7 by screening for the eae gene, after IMS – positives are then analyzed with Assurance GDS Shiga Toxin Genes (Top 7)
- Top 6 STEC methods that do not include E. coli O157:H7 results are also available in both formats
Confirmation and Identification
IMS kits are available to aide in isolation and confirmation of Top STEC serogroups. Both kits (Poly IMS & IMS Panel) can be used with Assurance GDS PickPen® to selectively capture the target serogroups prior to selective agar plating as specified by ISO for cultural confirmation. In addition, a serogroup identification kit (MPX ID) is also available which can determine which specific Top 6 non-O157 STEC serogroup(s) is present in product testing positive for STEC.
Assurance GDS Benefits:
- Top 7 STEC results available in 12 h, with genetic confirmation and identification results in 14 h
- PCR-based method easily implemented in industrial and commercial labs, no DNA extraction is required, complete automation is available
- Harmonized enrichment: same enriched sample can be tested for Salmonella and STEC including E.coli O157:H7 in 12 h
- Internal positive control present in each reaction tube, lyophilized reagents ready-to-use, IMS sample preparation prevents inhibition and increases sensitivity