Federal food safety officials said on Monday they would ban the sale of ground beef containing six toxic strains of E. coli bacteria that have increasingly been showing up in the food supply, taking a long-delayed step that was opposed by many in the meat industry.

Dr. Elisabeth Hagen, the head of food safety for the Department of Agriculture, which regulates meat, told the New York Times, “This is one of the biggest steps forward in the protection of the beef supply in some time. We’re doing this to prevent illness and to save lives.”

The new rule means that six lesser-known forms of E. coli will be treated the same as E. coli O157:H7, which was declared an adulterant in 1994.

The American Meat Institute said in a statement, “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. It is neither likely to yield a significant public health benefit nor is it good public policy.”

While several outbreaks caused by the Big Six E. coli strains have been linked to produce, the group pointed to the fact that only one has been tied to ground beef. In that outbreak, which occurred last year, three people were sickened.

Some meat processors have begun to test for the six strains in recent months in anticipation of federal action, but many others will most likely begin testing once the new rule takes effect.

Under the rule, any meat that is found to contain the Big Six E. coli, in tests by government or industry, will have to be diverted for use in cooked products. The bacteria is killed by heating the meat to 160 degrees.

USDA estimated that the new rule would cost the industry up to $10 million a year for testing and diverting meat to cooked products.

Details will be discussed at a press conference hosted by USDA on Tuesday morning.