PFGE for Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) and non-O157 STEC.

This chapter describes the procedure of generating pulsed-field gel electrophoresis (PFGE) profiles (DNA fingerprints) of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) and non-O157 STEC strains within 48 h, based on the standardized laboratory protocol developed by the Centers for Disease Control and Prevention, USA. The protocol describes the preparation of agarose plugs containing STEC O157 and non-O157 STEC cells, the digestion of bacterial DNA in the plugs using restriction endonuclease enzymes, and the electrophoresis conditions to generate the characteristic PFGE profiles of STEC O157 and non-O157 STEC isolates.