The FDA said Thursday that it's looking into whether McDonald’s supplier Taylor Farms is the possible source of the E. coli outbreak linked to Quarter Pounders burgers.

Taylor Farms, an onion suppler for McDonald's where Quarter Pounders are linked to an E. coli outbreak, is the subject of a separate onion recall.

The E. coli infections, first reported on Sept. 27 in Colorado, were linked to the recent consumption of Quarter Pounder hamburgers. The Food and Drug Administration, one of several authorities investigating the outbreak, has said that the slivered onions on the burgers are a "likely source of contamination."