U.S. Agriculture Department scientists have developed a new detection system for E. coli that simplifies and speeds up testing and may reduce illnesses from bacteria in beef, fresh produce and other foods.
The new test is a “two-for-one” process that detects both E. coli and toxins the bacteria produces that cause nausea, vomiting and diarrhea, said John Mark Carter, the USDA scientist who led the project.
Currently, separate tests are required to detect each threat, and results are typically available in three to five days. With the new test, results can be known in 24 hours, Carter said.
“This hopefully will make food testing faster, easier and more widely available to producers,” Carter said in an interview. Carter announced the new test at an American Chemical Society meeting in
The test could be used by meat processors for in-house testing of products prior to sale, said Carter, who’s with the USDA’s Agricultural Research Service in
“This would reduce the frequency of foodborne illness, reduce product recalls, and enhance public health while reducing annual cost for food testing,” Carter said in a statement.
The new test uses microscopic plastic beads, each about 1/100th the width of a grain of sand and containing a fluorescent dye. The beads are coated with antibodies that lock onto proteins or antigens present on E. coli and its two main toxins.
During testing, the beads are mixed with ground beef or other food samples and separated and run through an instrument, which then identifies beads that have latched onto E. coli antigens.
Tests were run on ground beef, as well as lettuce and milk, Carter said. The system “seems to work equivalently well in whatever we tested it on,” he said.
Carter wants to expand the system’s detection capabilities beyond E. coli O157, which accounts for about half of E. coli-related illnesses, into other strains of the bacteria, as well as other foodborne microbes such as Listeria and Salmonella. “We want to make this a 10- to 20-tests-in-one,” he said.
Food poisoning caused by E. coli O157 sickens more than 70,000 people each year in the
USDA researchers are developing a second-generation testing kit with Luminex Corp., an Austin, Tex.-based biological testing company. The researchers hope to have the kit commercially available by summer 2011, Carter said.
The “first-generation” test kit costs around $70,000 to $80,000, Carter said. He declined to say what the second-generation kit will cost.