ST. PAUL, Minn. — The first outbreak linked to a rare strain of E. coli in ground beef is prompting a fresh look at tougher regulations to protect the nation’s meat supply.

Three people in Maine and New York became ill this summer after eating ground beef traced back to a Cargill plant in Pennsylvania. Cargill recalled about 8,500 pounds of ground beef on Saturday and regulators warned consumers to throw out frozen meat purchased at BJ’s Wholesale Clubs in eight eastern states.

The new undersecretary of food safety at the U.S. Department of Agriculture, Dr. Elisabeth Hagen, has signaled interest in expanding federal oversight of meat beyond the most prevalent strain of E. coli. Meat plants already must test for that strain.

The link was first reported by The New York Times.