Testing has ruled out beef patties as the source of the outbreak of E. coli poisoning tied to McDonald鈥檚 Quarter Pounders, the company said Sunday. It will resume selling the Quarter Pounder in the coming week.

The U.S. Food and Drug Administration continues to believe that slivered onions from a single supplier are the likely source of contamination, McDonald鈥檚 said.

As of Friday, the outbreak had expanded to at least 75 people sick in 13 states, federal health officials said. A total of 22 people have now been hospitalized, and two have developed a dangerous kidney disease complication, the Centers for Disease Control and Prevention said. One person has died in Colorado.

Early information analyzed by the FDA showed that uncooked slivered onions used on the burgers 鈥渁re a likely source of contamination,鈥� the agency said. McDonald鈥檚 has confirmed that Taylor Farms, a California-based produce company, was the supplier of the fresh onions used in the restaurants involved in the outbreak, and that they had come from a facility in Colorado Springs, Colorado.

The 900 McDonald鈥檚 restaurants that normally received slivered onions from Taylor Farms鈥� Colorado Springs facility will resume sales of Quarter Pounders without slivered onions, McDonald鈥檚 said.

Taylor Farms said Friday it had preemptively recalled yellow onions sent to its customers from its Colorado facility and continues to work with the CDC and the FDA as they investigate.

The outbreak involves infections with E. coli 0157:H7, a type of bacteria that produces a dangerous toxin. It causes about 74,000 infections in the U.S. annually, leading to more than 2,000 hospitalizations and 61 deaths each year, according to CDC.