C.diphtheriae can be biochemically differentiated from C.ulcerans by
Among the Corynebacterium species, all are catalase positive. All are resistant to tellurite. All Corynebacterium species are oxidase negative. C. ulcerans is differentiated from C. diphtheriae by its negative nitrate reduction and positive gelatin liquefaction. 3 species produce diphtheria toxin: C. diphtheriae, C. ulcerans, and C. pseudotuberculosis. C. ulcerans- closely related to C.diphtheriae; causes bovine mastitis; Can cause acute pharyngitis in humans; C. ulcerans has been repoed to cause a few cases of diphtheria
Catalase test
Urease test
Oxidase test
Nitrate Reduction
Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli)