McDonald's Quarter Pounder Beef Patties Not Source of E.Coli Outbreak, Company Says

Samples of the beef patties used in McDonald's Quarter Pounders did not contain any E. coli has not been identified that has been linked to a fatal outbreak, a company spokesman said Sunday, citing tests by the Colorado Department of Agriculture.

The department has no further plans to test the beef patties, a company spokesman said, and the patties have been ruled out as the source of the outbreak.

Citing the Food and Drug Administration, a company spokeswoman said the most likely source of contamination was harvesting onions from a single source.

TAYLOR FARMS COLORADO SPRINGS – McDonald's indefinitely stopped sourcing slivered onions from that source on Sunday, a company spokeswoman said, days after it removed Taylor Farms onions from its supply chain.

Taylor Farms onions were sold in stores in parts of Colorado, Kansas, Wyoming and other states in the area, the spokeswoman said. Some of these locations include airports, which may be liable for lawsuits in other states.

A McDonald's spokeswoman said the company is confident in asking beef suppliers to supply new patties for distribution. The quarter pounder is expected to be available at restaurants this week.

The 900 restaurants that get onions from Taylor Farms Colorado Springs will continue to sell quarter pounders without onions for the time being, a company spokeswoman said.

No other burgers or McDonald's menu items were affected by the outbreak.

The strain of E. coli in the outbreak, called O157:H7, produces a powerful toxin that can damage the lining of the small intestine.

The outbreak was first reported Tuesday, when the Centers for Disease Control and Prevention announced that an E. coli outbreak, prompting the fast-food chain to stop using slivered onions and quarter-pound beef patties. In several states, the agency said at the time.

The CDC said Tuesday that the first E. coli case occurred on September 27. Colorado state health officials notified the CDC of the unusual increase in illnesses on Oct. 10, and the agency began an investigation on Oct. 15, Matt Wise, chief of the CDC's Outbreak Response and Prevention Branch, told NBC News.

The CDC zeroed in on the investigation of onions sleeved into quarter pounders by Wednesday. On Thursday, McDonald's said the onions linked to the outbreak came from Taylor Farms.

On Wednesday, distributor US Foods said Taylor Farms is recalling four raw onion products out of an abundance of caution due to “potential E. coli contamination.” The company urged its customers, including restaurants, to stop using and destroy affected products as soon as possible.

It also prompted other restaurant chains in Colorado — including Illegal Pete's and Taco Bell — to stop using onions on their menus.

A spokesperson for Yum! Brands, the parent company of Taco Bell, said select Pizza Hut and KFC locations have removed fresh onions from their menus. Associated with these restaurants e. No symptoms of cholera

The FDA said Thursday that it has linked the quarter pounder to E. coli is looking at Taylor Farms as a possible source of the outbreak but added that “we are looking at all possible sources.”

A spokesman for Taylor Farms did not immediately respond to a request for comment Sunday.

As of Friday, 75 people across 13 states. coli strain and one person died, according to the CDC.

Twenty-two people were hospitalized, and two people developed hemolytic uremic syndrome, a serious complication that can lead to permanent kidney failure or death.

Multiple people have sued McDonald's after they became ill after eating at the restaurant.