NEOGEN EC Medium, Modified

EC Medium, Modified is used with novobiocin for the selective pre-enrichment of Escherichia coli O157:H7 in a laboratory setting. EC Medium, Modified is not intended for use in the diagnosis of disease or other conditions in humans. EC Medium was developed by Hajna and Perry in an effort to improve the methods for the detection of the coliform group and E. coli. This medium consists of a buffered lactose broth with the addition of 0.15% Bile Salts Mixture. Growth of spore-forming bacteria and fecal streptococci were inhibited by the bile salts. EC Medium, Modified with the addition of novobiocin was first described by Okrend and Rose. Okrend and Rose modified EC Medium by reducing the Bile Salts Mixture concentration to 1.12% and adding 20 mg/L of sodium novobiocin. Okrend and Rose et al. reported this formulation, which they called Modified EC & Novobiocin (mEC&N), was beneficial in the enrichment and detection of E. coli O157:H7 from meats and poultry, and is currently recommended by the U.S.D.A.