Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Corynebacterinae, Family
Corynebacteriaceae, Genus Corynebacterium, Corynebacterium aurimucosum Yassin, Steiner and Ludwig 2002 emend. Daneshvar
et al. 2004.
Historical synonym: C. nigricans it is a later heterotypic synonym of C. aurimucosum
Yassin et al. 2002 emend. Daneshvar et al. 2004.
Gram-positive, thin, pleomorphic coryneform cells. Nonmotile. Nonspore-forming.
C. aurimucosum grows on BHI agar supplemented with 1 % Tween 80 (some strains
are able to form a coralloid precipitin in agar when grown in the presence of CO2),
Columbia blood agar supplemented with 5% sheep blood (the colonies are sticky and
slightly yellow in colour) and TSA (they appear colourless and slimy). Facultatively
anaerobic. Can grow in: 0-6% NaCl broth. Grows at 35-42 ºC, but not at 25 ºC.
C. nigricans produce black pigmentation on hem-containing sheep blood agar, colistin-
naladixic acid agar, chocolate agar, and non-hem-containing BHI agar after 24 to 48 h of incubation; these could be the criteria to
distinguish this coryneform from other coryneforms. The pigment is not water soluble. Colonies also turn black on trypticase soy agar
after 4 to 5 days.
Isolated from a human clinical specimen.
- Yassin A.F., Steiner U. and Ludwig W., 2002. Corynebacterium aurimucosum sp. nov. and emended description of
Corynebacterium minutissimum Collins and Jones (1983). IJSEM 52, 1001-1005.
- 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.
- Daneshvar M.I. et al., 2004. Identification of Some Charcoal-Black-Pigmented CDC Fermentative Coryneform Group 4 Isolates as
Rothia dentocariosa and Some as Corynebacterium aurimucosum: Proposal of Rothia dentocariosa emend. Georg and Brown
1967, Corynebacterium aurimucosum emend. Yassin et al. 2002, and Corynebacterium nigricans Shukla et al. 2003 pro synon.
Corynebacterium aurimucosum. J. Clin. Microbiol. Vol. 42, No.9, 4189-4198.
Fermentative metabolism. Non-acid-fast.
Positive results for alkaline phosphatase, catalase, hippurate hydrolysis, pyrazinamidase, Voges-Proskauer test, acid production
from: fructose, glucose, maltose & sucrose.
Negative results for acid phosphatase, arginine dihydrolase, esculin hydrolysis, gelatin hydrolysis, indole production, lipophilism,
nitrate reduction, oxidase, starch hydrolysis, trypsin, chemotrypsin, urease, alpha- and beta-glucosidase, alpha- and
beta-galactosidase, beta-glucuronidase, N-acetyl-beta-glucoseaminidase, alpha-mannosidase, alpha-fucosidase, pyrrolidonyl
arylamidase, acid production from: adonitol, amygdalin, arabinose, cellobiose, glycerol, glycogen, inulin, lactose, mannitol, mannose,
melezitose, raffinose, rhamnose, ribose, salicin, sorbitol, trehalose & xylose.
(c) Costin Stoica