Officials say four kinds of salmonella have been identified in the growing investigation of tainted peanut products.
A congressional official briefed on the investigation says health officials have identified four types of salmonella as they focus on a Georgia facility. The official spoke on condition of anonymity because the investigation is continuing.
Meanwhile, the recalls list has grown to more 390 products, from ice cream to dog biscuits.
More than 500 people have gotten sick, and the outbreak is believed to have contributed to eight deaths.
Salmonella Typhimurium is the strain that caused the illnesses. Two other strains were found on the floor of the facility and a third in a container of peanut butter from the plant.