Corynebacterium ulcerans

**Semantic type:** Bacterium

**Definition:** A species of aerobic or facultatively anaerobic, Gram-positive, coryneform, pleomorphic bacilli assigned to the phylum Actinobacteria. This species is nonmotile, non-spore forming, catalase positive, oxidase negative, does not reduce nitrate, hydrolyzes gelatin and hippurate but not urease or esculin and is not acid fast. C. ulcerans is commensal to the animal and human nasopharynx, but toxin producing strains can cause diphtherial-like illness.

**Synonyms:** - CORYNEBACTERIUM ULCERANS