S. gallolyticus subsp. pasteurianus
alpha-haemolytic colonies on sheep blood agar
S. gallolyticus subsp. pasteurianus
Gram-stained cells
Streptococcus gallolyticus
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Bacilli, Order Lactobacillales, Family Streptococcaceae, Genus Streptococcus, Streptococcus gallolyticus  
Osawa et al. 1996.

Divided in 3 subspecies:
- Streptococcus gallolyticus subsp. gallolyticus  Osawa et al. 1996 (synonym: Streptococcus caprinus  Brooker et al. 1996),
- Streptococcus gallolyticus subsp. macedonicus  (Tsakalidou et al. 1998)  Schlegel et al. 2003 (synonym: S. waius Flint et al. 1999),
- Streptococcus gallolyticus subsp. pasteurianus  (Poyart et al. 2002)  Schlegel et al. 2003 (synonym: Streptococcus bovis biotype II/2).

Lancefield group D or nongroupable.
Gram-positive cocci, nonmotile, grouped in pairs or chains.
Small, non-pigmented colonies. Usually alpha-haemolytic. Grow at 37 ºC. Aerobic,
facultatively anaerobic. Growth on complex media: Trypticase soy agar with 5% sheep
blood, Edwards agar, Slanetz & Bartley agar, Brain heart infusion medium, Columbia
Agar base enriched with starch 1.5%.
Isolated from animal feces (ruminants, horses, dogs,  birds, koalas, kangaroos),
aliments (milk, cheese), human clinical samples.
Involved in tannin digestion in ruminants (subsp. gallolyticus). Opportunistic
pathogen. May produce mammites in bovines, septicemia in birds (pigeons, ducks).
Endocarditis in humans.
  1. Osawa R., Fujisawa T. & Sly L.L.: Streptococcus gallolyticus sp. nov.; gallate degrading organisms formerly assigned to
    Streptococcus bovis. Syst. Appl. Microbiol., 1995, 18, 74-78.
  2. Sly L.I., CahillL M.M., Osawa R. & Fujisawa T.: The tannin-degrading species Streptococcus gallolyticus and Streptococcus caprinus
    are subjective synonyms. Int. J. Syst. Bacteriol., 1997, 47, 893-894.
  3. Schlegel L., Grimont F., Ageron E., Grimont P.A.D. & Bouvet A.: Reappraisal of the taxonomy of the Streptococcus
    bovis/Streptococcus equinus complex and related species: description of Streptococcus gallolyticus subsp. gallolyticus subsp. nov.,
    S. gallolyticus subsp. macedonicus subsp. nov. and S. gallolyticus subsp. pasteurianus subsp. nov. Int. J. Syst. Evol. Microbiol.,
    2003, 53, 631-645.
  4. Luc A. Devriese,Peter Vandamme, Bruno Pot, Mia Vanrobaeys, Karel Kersters, & Freddy Haesebrouck: Differentiation between
    Streptococcus gallolyticus Strains of Human Clinical and Veterinary Origins and Streptococcus bovis Strains from the Intestinal
    Tracts of Ruminants. J Clin Microbiol. 1998 December; 36(12): 3520–3523.
  5. Robert A. Whiley and Jeremy M. Hardie, 2009. Genus I. Streptococcus Rosenbach 1884, 22AL. In: (Eds.) P.D. Vos, G. Garrity, D.
    Jones, N.R. Krieg, W. Ludwig, F.A. Rainey, K.-H. Schleifer, W.B. Whitman. Bergey’s Manual of Systematic Bacteriology, Volume 3:
    The Firmicutes, Springer, 655-711.
Subsp. gallolyticus can hydrolyse tannins (gallate decarboxylase producer).
Differences from
subsp. gallolyticus:
Subsp. macedonicus
does not produce acid from esculin and inulin.
Subsp. pasteurianus is positive for beta-glucuronidase (negative on some API tests -
admin note) and beta-galactosidase.

Common characters:
Positive results for beta-glucuronidase, beta-galactosidase, Voges-Proskauer,
hydrolysis of esculin and starch, acidification of  lactose, trehalose, inulin and

Negative results for pyrrolidonearylamidase, hydrolysis of hippurate, alkaline
phosphatase, arginine, xylitol, D- and L-xylose.
(c) Costin Stoica
Culture media
Biochemical tests
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