Phylum Actinobacteria, Class Actinobacteria, Order Micrococcales, Family Brevibacteriaceae, Genus Brevibacterium, Brevibacterium
casei Collins, Farrow, Goodfellow and Minnikin 1983.
Historical synonyms: CDC coryneform groups B-1 and B-3.
Gram-positive relatively short rods with a marked rod-coccus cycle when growing on
complex media; culture up to 24 h produce coryneform rods with V arrangements,
while older cells are coccoid or coccobacillary and decolorize easily. Nonmotile.
Spores are not produced. Mycolic acids are not present.
Colonies are opaque, convex, smooth and shiny surface, grey-white, mostly creamy,
larger than 2 mm in diameter after 24 hours of incubation at 30-37 ºC in 5% CO2
atmosphere on 5% sheep blood Columbia agar; cheese-like odour. Later, they
become larger and may turn slightly yellowish or greenish. Nonhemolytic. CAMP test
negative. Nonfastidious. Halotolerant (15% NaCl). Obligate aerobic. Can grow at 20
and 37 ºC, but not at 10 ºC. Survive at 60 ºC.
Habitats include human skin, raw milk, surface-ripened cheeses, animal sources. May contribute to the malodour of some people’s
Susceptible to gentamicin, rifampin, tetracycline and glycopeptide antibiotics. Resistant to beta-lactams, ciprofloxacin, clindamycin
and erythromycin. Resistant to thallium acetate.
It have been described human osteomyelitis, peritonitis and septicemia.
- 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.
- Trujillo M.E. and Goodfellow M., 2012. Genus I. Brevibacterium Breed 1953, emend. Collins, Jones, Keddie and Sneath 1980.In:
Goodfellow M., Kampfer P., Busse H.J., Trujillo M.E., Suzuki K., Ludwig W. and Whitman W.B. (Editors), Bergey’s Manual of
Systematic Bacteriology, second edition, Vol. Five, The Actinobacteria, Part A, Springer, Athens, pp. 685-700.
Not acid fast. Oxidative metabolism.
B. sanguinis is very similar to B. casei when tested by conventional methods or commercial identification sets but susceptibility to
thallium acetate may help to differentiate the two species in the routine laboratory (B. sanguinis is susceptible to thallium acetate).
Positive results for casein hydrolysis, catalase, DNA hydrolysis, gelatin hydrolysis, pyrazinaminidase, xanthine hydrolysis, acid
production from glucose (weak reaction) & phenyl acetate.
Negative results for esculin hydrolysis, N-acetyl-beta-glucosaminidase, oxidase, starch hydrolysis, urease, acid production from:
2,3-butylene glycol, mannitol & xylose.
Variable results for alpha-glucosidase, nitrate reduction & pyrrolidone arylamidase.
(c) Costin Stoica