Development of a rapid shiga toxin diagnostic array

Several strains of Shiga toxin-producing Escherichia coli (STEC) are responsible for 265,000 intestinal infections per year in the United States. Multiple food-borne outbreaks have resulted from the consumption of undercooked meat, raw milk and milk products, unpasteurized juices, and vegetables such as lettuce, spinach, and chili peppers. Infection can result in acute diarrhea, hemorrhagic colitis and, in 5% to 15% of cases, life-threatening hemolytic uremic syndrome (HUS). HUS is marked by kidney failure, hemolytic anemia, and clotting disorders, which can result in long-term vascular and neurological damage or death, with children and the elderly the most susceptible.

Two immunologically distinct types of Shiga toxin, Stx1 and Stx2, are responsible for all of these disease manifestations. The timely diagnosis of STEC has been held back by the slowness of culture methods (growing the bacteria) and the difficulty diagnosing certain strains by culturing. Existing toxin detection kits did not provide the sensitivity necessary for rapid same-day testing of fecal samples or for point-of-care diagnosis (physician?s office, clinics).

The technology developed and transferred by the Uniformed Services University of the Health Sciences (USU) addresses these issues in two assay formats that can detect Shiga toxin produced by multiple strains of E. coli. The Shiga toxin detection technology is protected by an issued U.S. patent for the direct detection of Stx1 and Stx2 in food and clinical samples. The diagnostic assay protected by the patent utilizes monoclonal antibodies to both Stx1 and Stx2, and provides a method to detect the Shiga toxins produced by STEC.

The Shiga toxin diagnostic technology was successfully licensed to Alere, a company with a focus on innovative diagnostic products. To further the development of the Shiga toxin technology into a commercial product, a Cooperative Research and Development Agreement with Alere and TechLab® (sublicensee of Alere) was executed.

The development of two Shiga toxin diagnostic assays, SHIGA TOXIN CHEK and SHIGA TOXIN QUIK CHEK, provides rapid tests that are able to detect and differentiate Stx1 and Stx2 toxins from STEC, allowing for the timely diagnosis of STEC and the implementation of an appropriate treatment plan.

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Mid-Atlantic