For years, the beef industry and the U.S. governmenthave battled E. coli O 157:H7 — the most insidious among pathogens causing foodborne illnesses, to say nothing of its major threat to the viability of ground beef.For years, the beef industry and the U.S. governmenthave battled E. coli O 157:H7 — the most insidious among pathogens causing foodborne illnesses, to say nothing of its major threat to the viability of ground beef. This seems a Sisyphean effort given the spate of recalls in 2007, especially the one ultimately forcing Elizabeth, N.J.-based Topps Meat Company LLC, the largest U.S. manufacturer of frozen hamburger, to go out of business.