Public health laboratories routinely serotype Salmonella and Shigella isolates, and routinely subtype all isolates of Listeria and Shiga toxin-producing E. coli (STEC) by pulsed-field gel electrophoresis (PFGE). Many also subtype representative samples of Salmonella and Shigella isolates with PFGE, among other foodborne pathogens. For more information on the national network of public health and food regulatory agency laboratories conducting molecular surveillance, visit the PulseNet website.