The Food Safety and Inspection Service (FSIS) is confirming that it will implement routine verification testing for six Shiga toxin-producing Escherichia coli (STEC), in addition to E. coli O157:H7, in raw beef manufacturing trimmings beginning June 4, 2012. 

Source: Federal Register. “Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products”.  77 FR 31975, May 31, 2012.  
https://www.federalregister.gov/articles/2012/05/31/2012-13283/shiga-toxin-producing-escherichia-coli-in-certain-raw-beef-products