ACS News Service Weekly PressPac: Fri Mar 19 16:42:03 EDT 2010

A two in one test for detecting E coli in ground beef

EMBARGOED FOR RELEASE: Tuesday, March 23, 5 p.m., Eastern Time

Scientists today reported development of the first two-in-one test that can simultaneously detect both the E. coli bacteria responsible for terrible food poisoning outbreaks, and the toxins, or poisons, that the bacteria uses to cause nausea, vomiting, diarrhea and other symptoms in its victims. They described it at the 239th National Meeting of the American Chemical Society (ACS), being held here this week.

Until now, there was no two-in-one test for the bacteria and the toxins. Separate tests were required for each threat. Current tests for E. coli in beef also are time-consuming. The results take 3 to 5 days. The new test cuts the waiting time to just 24 hours, the researchers say. The test is slightly less sensitive than current tests, but scientists think the sensitivity can be improved.

The new test uses microscopic plastic beads, each 1/100th the width of a grain of sand, containing a fluorescent dye. The beads, customized in Carter’s lab, are coated with antibodies that lock onto proteins or antigens present on E. coli and its two main toxins. During the test, the beads are mixed together with ground beef or other food samples and then separated and run through an instrument. It identifies beads that have latched onto the E. coli antigens.


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A new test can speed detection of
E. coli
and its toxins. Credit: iStock
(High-resolution version)