Corynebacterium ulcerans cultivated on Tinsdale agar (TIN).
Cultivation 48 hours, 36 °C in an aerobic atmosphere.

Corynebacterium ulcerans and C.pseudotuberculosis also produce a charasteristic halo on Tinsdale agar. Both of them are urea positive and have a positive reverse CAMP test (unlike C.diphtheriae). All of them can harbor the diphtheria toxin gene.