Cultural characteristics
Biochemical characters
Phylum Actinobacteria, Class Actinobacteria, Subclass Actibacteridae, Order Actynomycetales, Suborder Corynebacterinae, Family
Corynebacteriaceae, Genus Corynebacterium,
Corynebacterium afermentans Riegel, De Briel, Prevost, Jehl, Monteil & Minck, 1993.
2 subspecies:
- C. afermentans subsp. afermentans,
- C. afermentans subsp. lipophilum.
Historical synonyms: CDC coryneform group ANF-1 (absolute nonfermentative).
Gram-positive, typical irregular coryneform rods or coccobacilli, that sometimes
contain metachromatic granules; arranged  in typical V-shaped forms or palisades.
Nonmotile. Nonsporing.
Colonies: 1.0- 2.0 mm in diameter after 24 h of incubation at 37 ºC on sheep blood
agar for
subsp. afermentans and less than 0.5 mm for the grayish, glassy colonies
subsp. lipophilum on same media but subsp. lipophilum colonies reach 2-3 mm
on sheep blood agar with  1% Tween 80 (
subsp. afermentans is not significantly
influenced by Tween 80).
Subsp. afermentans colonies are whitish, creamy, smooth, convex with regular edges.
Subsp. lipophilum colonies are beige, without a mucoid consistency on media with Tween 80.
Hemolysis is not produced. CAMP reaction is variable. Grow well under aerobic conditions and very slight under anaerobic conditions.
Can grow in 6.5% NaCl media.
Isolated mainly from the human blood cultures. Is part of the normal human skin flora.
Is generally susceptible to β-lactam antibiotics, ampicillin, cephalotin, gentamicin, norfoxacin, vancomycin, rifampicin & tetracycline.
A prosthetic valve endocarditis with perivalvular abscess formation due to C. afermentans subsp. lipophilum was described.
Also, it was described an immunocompetent  patient who developed a brain abscess from which
C. afermentans subsp. lipophilum
was isolated.
  1. 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.
  2. 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.
  3. Riegel P., De Briel D., Prevost G., Jehl F., Monteil H. and Minck R., 1993. Taxonomic study of Corynebacterium Group ANF-1
    strains: proposal of Corynebacterium afermentans sp. nov, containing the subspecies C. afermentans subsp. afermentans
    subsp. nov. and C. afermentans subsp. lipophilum subsp. nov. IJSB Vol.43, No. 2, p.287-292.
Not acid fast. Oxidative metabolism.

Positive results for acid phosphatase, alkaline phosphatase, catalase, lipase & pyrazinamidase.

Negative results for DNA degradation, esculin hydrolysis, esterase production, gelatin hydrolysis, alpha- or beta-galactosidase, alpha-  
or beta-glucosidase, H
2S production, hippurate hydrolysis (variable for subsp. afermentans) indole production, lipophilism (positive for
subsp. lipophilum),
methyl red, nitrate reduction, oxidase, starch hydrolysis, tyrosine degradation, urease, Voges-Proskauer reaction,
acid production from: galactose, glucose, glycogen, lactose, maltose, mannitol,  mannose, ribose, sucrose, trehalose & xylose.
Corynebacterium afermentans
(c) Costin Stoica
Culture media
Biochemical tests
Previous page