Federal food safety regulators will ban the sale of ground beef tainted with six E. coli strains, expanding efforts to combat the bacteria amid growing concern over illnesses and deaths linked to less-common forms of the pathogen.

The six strains, or serotypes, will be declared “adulterants” in “non-intact” raw beef, which includes raw ground beef and tenderized steaks, the U.S. Department of Agriculture said in a Sept. 13 announcement.

Selling ground beef contaminated with O157:H7, the strain responsible for nearly all reported E. coli illnesses and product recalls for many years, has been prohibited since 1994. Banning the additional strains will help proactively ensure the safety of the country’s food amid the increasing emergence of rarer, yet still toxic, forms of E. coli, regulators said.

“The Obama Administration is committed to protecting our food supply and preventing illnesses before they happen,” Agriculture Secretary Tom Vilsack said in the statement. The new policy “does exactly that by targeting and eliminating contaminated products from the market.”

“Too often, we are caught reacting to a problem instead of preventing it,” Vilsack said. “This new policy will help stop problems before they start.”

The Food Safety and Inspection Service, the USDA agency responsible for meat and eggs, will begin testing for the six strains and start enforcing the new policy in March. The six strains are among Shiga-toxin producing E. coli, or STEC, that can cause severe illness or death, particularly among children and the elderly, the USDA said.

E. coli can be found in cattle intestines, and recorded illnesses from O157:H7 have declined for several years as meat processors stepped up testing. But the rarer strains gained attention in the wake of recent outbreaks from contaminated lettuce, spinach and other vegetables. Last spring in Europe, more than 4,000 were sickened and at least 49 died in an E. coli outbreak blamed on sprouts.

Last year in the U.S., reported illnesses from non-O157 E. coli strains surpassed those from O157 for the first time, according to the Centers for Disease Control and Prevention.

The U.S. meat processing industry, which has long opposed any expansion of the E. coli ban, said the new policy is not supported by science and will raise costs for consumers. Current safety practices are strong enough to eliminate all E. coli strains, not just O157, the American Meat Institute has said.

“Imposing this new regulatory program on ground beef will cost tens of millions of federal and industry dollars – costs that likely will be borne by taxpayers and consumers,” James Hodges, executive vice president with the institute, said in a Sept. 13 statement.

“It is neither likely to yield a significant public health benefit nor is it good public policy,” Hodges said. The Washington, D.C.-based institute represents most of the country’s meat processors.

According to the institute, there is only one recorded U.S. outbreak involving beef tainted with non-O157 E. coli. In that case, Cargill Inc.’s meat processing unit in August 2010 recalled 8,500 pounds of ground beef from a Pennsylvania plant because it may have been contaminated with E. coli O26. That strain is one of the six that will be banned by the USDA. The others are O103, O45, O111, O121 and O145. The three people sickened in that outbreak recovered, Hodges said.

Public health data indicates “there is no public health crisis related to those strains in ground beef,” Hodges said.

The new USDA policy comes amid a broader Obama Administration effort to overhaul the nation’s food safety system. Elisabeth Hagen, head of the USDA’s food safety, said the policy reflects a wider commitment to deal with “emerging microbial threats.”

“Consumers deserve a modernized food safety system that focuses on prevention and protects them and their families from emerging threats,” Hagen said in the USDA’s statement. As non-O157 STEC bacteria have emerged and evolved, “so too must our regulatory policies to protect the public health and ensure the safety of our food supply,” she said.

E. coli can cause bloody diarrhea, severe stomach cramps, vomiting and kidney failure. According to the Centers for Disease Control and Prevention, the various E. coli strains cause an estimated 173,000 illnesses and 21 deaths every year in the U.S.