E. coli O157:H7 is a facultative Gram negative rod. Colourless colonies from 2-3 mm in diameter can be found when grown on sorbitol MacConkey agar SMAC or SMAC containing cefixime and tellurite CT-SMAC.
E. coli O157:H7 es un bacilo facultativo Gram negativo, presenta colonias hialinas de 2-3 mm de diámetro en agar MacConkey sorbitol SMAC o SMAC adicionado con cefixima y telurito CT-SMAC.