Streptococcus gallolyticus
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Bacilli, Order Lactobacillales, Family Streptococcaceae, Genus Streptococcus, Streptococcus gallolyticus  
Osawa et al. 1996. Synonyms: Streptococcus caprinus  Brooker et al. 1996 is a later heterotypic synonym.
Lancefield group D or nongroupable.

Divided in 3 subspecies:
- Streptococcus gallolyticus subsp. gallolyticus  Osawa 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.
Gram-positive cocci, nonmotile, grouped in pairs or chains.
Small, non-pigmented colonies. Growth 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).
Beta-glucuronidase, beta-galactosidase, Voges-Proskauer, hydrolysis of esculin &
starch, acidification of  lactose, trehalose, inulin & mannitol are positive
Pyrrolidonearylamidase, hydrolysis of hippurate, alkaline phosphatase, arginine, beta-
glucuronidase, xylitol, D- & L-xylose are negative
Differences from
subsp. gallolyticus:
Subsp. macedonicus
is esculin & inulin negative.
Subsp. pasteurianus is beta-glucuronidase & beta-galactosidase positive,
(c) Costin Stoica
Culture media
Biochemical tests
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