Colonies produced by L. monocytogenes, L. ivanovii, and L. innocua on MOX (A, B, and C) and LL medium (D, E, and F). L. monocytogenes (A), L. ivanovii (B), and L. innocua (C) appeared as black colonies with a black halo on MOX. On LL medium, L. monocytogenes (D) and L. ivanovii (E) produced white colonies with a halo, whereas L. innocua (F) produced white colonies without a halo.