Source: JoNel Aleccia / MSNBC Federal agriculture officials are expanding long-delayed rules that will ban six new strains of potentially lethal E. coli bacteria from the nation's meat supply, msnbc.com has learned. Under the new regulations, a group of E. coli bacteria collectively dubbed the "the big six" capable of causing infection and death will be classified as adulterants on par with the better-known E. coli 0157:H7, the bug frequently linked to serious foodborne illness from tainted ground beef. Starting [...]