Glycoconjugates Pinpoint Shiga Toxins

If the food-borne bacterium Escherichia coli O157:H7 introduces Shiga toxin 2 (Stx2) into a person's gut, that individual has a significant risk of developing hemolytic uremic syndrome, a cause of renal failure and death. But the bacterium's Stx1 toxin is much less dangerous. The two toxins are distinguishable in diagnostic tests that use monoclonal antibodies, but antibodies are expensive and require cold storage???which is not always feasible in developing countries, where most O157:H7 infections occur. Suri S. Iyer, Alison A. Weiss, and coworkers at the University of Cincinnati have now identified glycoconjugates that can differentiate between the toxins in stool samples at less expense and without the need for refrigeration (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200703680). The researchers hope to use the glycoconjugates in an assay kit for Stx1 and Stx2. Such a kit would enable doctors to quickly tell which patients can go home and which need to be admitted to a medical facility for further treatment, Iyer says.