The Ralphs supermarket chain has first pulled off suspected ground beef from its shelves in California, and now it has replaced the product using a different supplier which is not involved in the recall and is deemed safe.

Meanwhile, Kroger Co. will recall more ground beef after the U.S. Department of Agriculture identified the supplier as Nebraska Beef Ltd. Kroger said on Tuesday the recall now includes ground-beef products in Styrofoam tray packages enwrapped in clear cellophane or purchased from an in-store service counter in certain stores. The company is also recalling Private Selection Natural ground beef, which was available at all Kroger stores, sold in 16-ounce packages with "sell-by" dates July 11 to July 21 from the self-service meat case.

The product was available at Dillons, Fred Meyer, Baker's, Smith's and Fry's.

The US Centers for Disease Controls has managed to find the cause of the E. coli outbreaks that have hit Michigan and Ohio at the beginning of June. According to the CDC, the source of the infection was found to be ground beef.

It seems that most of the people that have been infected have bought the ground beef from the Kroger Food Store, which is US’s largest grocery chain. Kroger immediately announced that it supports the investigations and that it will do everything possible to help tracking down the source of the tainted meat.

People who have bought ground beef during May 31 and June 8, the period when most of the cases have been reported, are advised to throw it away. Furthermore, health specialists advise everyone that ground beef must be thoroughly cooked at a temperature of 160 degrees in order to make sure that it is safe to eat.

E. coli infections’ symptoms are diarrhea, stomach cramps and vomiting. Most of the infected persons get well in 15 days but there are severe cases which lead to kidney failure. It is estimated that there are about 70,000 E. coli infection cases in the US each year.

Just days after the Kroger Food Store announced it was voluntarily recalling all ground beef products that were sold between May 21 and June 8 at its stores following E. coli outbreaks in Michigan and Ohio, the U.S.’s largest grocery chain already faces its first lawsuit.

Amanda Adam from Ohio says she contracted E. coli from ground beef she purchased at a Kroger grocery store in Dublin, a Columbus suburb. The lawsuit accuses the grocer of negligence and seeks at least $25,000 in damages.

According to the lawsuit, she bought two beef patties on June 4 and cooked them the same day. Four days later, she began feeling ill and was admitted to a Cincinnati hospital on June 10. Tests at the hospital revealed she was infected with E. coli O157:H7, the same strain of the bacteria found in the Kroger ground beef outbreak.