Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Corynebacterinae, Family
Corynebacteriaceae, Genus Corynebacterium, Corynebacterium ulcerans (Gilbert and Stewart 1927) Riegel et al. 1995.
Resemble C. diphtheriae biotype gravis. Gram-positive, small irregular rods, 0.5-0.6 x
1.0-3.0 µm, staining irregularly, with club forms and metachromatic granules.
Grow well on blood agar: yellowish white, opaque convex colonies, dry and waxy, with
matt surface, 1 mm in diameter, often with a narrow zone of hemolysis around the
colony . Reverse CAMP test is positive. Aerobic growth.
Tellurium salts are reduced to tellurium (which is precipitated in the cell to color the
colonies blackish on blood tellurite agar).
Isolated mainly from the nasopharynx of healthy persons, from patiens with a diphtheria-like disease and from acute mastitis in cow;
also isolated from horses.
Can harbour the diphtheria toxin gene.
Many strains produce diphtheria toxin and a toxin resembling that of C. pseudotuberculosis. Toxinogenic C. ulcerans can cause a
disease indistinguishable from diphtheria; these strains were isolated from the pharyngeal membrane of a patient with laryngeal
diphtheria and from patients with less severe nasopharyngeal disease.
Nontoxinogenic strains has been associated with necrotic granulomas and pulmonary nodules in an immunocompetent host
the phospholipase D may represent a virulence factor.
- Funke G., von Graevenitz A., Clarridge III J.E., and Bernard K.A., 1997. Clinical Microbiology of Coryneform Bacteria. Clinical
Microbiology Rewiews Vol. 10, No. 1, p. 125-159.
- Funke G., 2006. Corynebacteria and rare coryneforms. In: Topley & Wilson’s Microbiology & Microbial Infections, 10th Edition,
Edited by Borriello S.P., Murray P.R. and Funke G.,Edward Arnold (Publishers) Ltd., Bacteriology, volume 2.
- Cummins C.S., Lelliott R.A. and Rogosa M., 1975. Genus Corynebacterium Lehmann and Neumann 1896 . In: Buchanan R.E.
and Gibbons N.E. (Editors), Bergey’s Manual of Determinative Bacteriology, Eight Edition, The Williams & Wilkins Company,
- Diaconescu A. si Damian M., 2009. Identificarea corinebacteriilor. In: Buiuc D., Negut M. (Editori), Tratat de Microbiologie Clinica,
Editia a III-a, Editura Medicala, Bucuresti, 620-651.
Fermentative metabolism. No oxidative metabolism. Non-partially-acid-fast.
Positive results for alkaline phosphatase, cistinase, H2S production on Tinsdale medium (containing L-cystine and potassium
tellurite), gelatinase, urease, acid production from: glucose, glycogen, maltose, trehalose & starch.
Negative results for esculin hydrolysis, lipophilism, nitrate reduction, pyrazinamidase, acid production from: mannitol, sucrose &
(c) Costin Stoica