Location: Produce Safety and Microbiology ResearchTitle: Rapid detection of E. coli produced shiga-like toxins by lateral flow immunoassay in multiple food matrices
Submitted to: Toxins
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2015
Publication Date: 4/3/2015
Citation: Ching, K.H., He, X., Stanker, L.H., Lin, A.V., Hnasko, R.M. 2015. Rapid detection of E. coli produced shiga-like toxins by lateral flow immunoassay in multiple food matrices. Toxins. Toxins 7:1163-1173.
Interpretive Summary: We have developed a simple, inexpensive, disposable lateral flow device for the rapid detection of shiga-like toxins (Stx) produced by shiga-toxigenic Escherichia coli (STEC) from contaminated foods. Our device detects all the common shiga toxin serotypes (type-1 and type-2 (A-G)) with a positive test indicated by a visible red line in <10 min. These test strips require minimal end-user training and can be used throughout food production to identify potential sites of STEC contamination and augment current testing procedures.
Technical Abstract: Shiga toxigenic E. coli (STEC) produce shiga-like toxins (Stx) that can cause human disease and death. The STEC serotype O157:H7 is a well-recognized foodborne contaminant and effective detection methods have been established. However, the emergence of non-O157 STEC strains has necessitated the development of additional detection strategies capable of identifying contamination of food products with these pathogenic STEC strains. In this manuscript we report the development of a new lateral flow immunoassay (LFIA) for the rapid detection of Stx in food matrices. Our Stx LFIA uses two novel monoclonal antibodies capable of detecting Stx1 and Stx2 variants directly from STEC culture supernatants and food matrices in < 10 min as a visible line using a gold label. The limit of detection (LOD) with these devices from Stx2a spiked beef, lettuce, and milk was 1 ng/mL. This immunoassay provides a simple, fast and inexpensive colorimetric test for the direct identification of Stx that can be performed by end-users with limited training to augment current test methods and improve food safety.