SPRINGDALE, ARK. — An agreement has been reached between Costco and Tyson Foods that allows Costco to test Tyson’s beef trimmings for E. coli before grinding and mixing, according to Newsinferno.com. As a result of this new agreement, Costco will begin buying beef trimmings for making hamburger from Tyson.

The N.Y. Times relayed in its Oct. 4 issue that much of the ground beef eaten in the U.S is made from beef trimmings from parts of the cow most likely to contain E. coli bacteria. However, most meat processors test their ground beef after trimmings from multiple slaughterhouses have been mixed and ground together — which makes it difficult to determine the original source of E. coli should it be found during later testing or in the event of an outbreak, the story charged.

Ground beef manufacturers are allowed by U.S.D.A. to create their own safety plans, and the agency only "encourages" them to test ingredients before using them, the article continued. However, most slaughterhouses will only sell to manufacturers who agree not to test ingredients for E. coli before use, the Times charged, because the slaughterhouses fear a positive E. coli test will lead to a recall of their ingredients.

Costco is one of several large ground-beef manufacturers that tests trimmings for E. coli as they arrive at its plant, before grinding, according to the Times. Previously, Tyson did not sell trimmings to Costco because of the latter company’s testing strategy, the story concluded.