Streptococcus acidominimus
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Bacilli, Order Lactobacillales, Family Streptococcaceae, Genus Streptococcus, Streptococcus acidominimus  
Ayers and Mudge 1922. Lancefield group G or non-groupable.

Human isolates previously identified as
Streptococcus acidominimus have been
identified as
Facklamia soureki.
Gram-positive cocci, grouped in short chains.
Alpha-hemolytic colonies. Growth temperature at 37.0 ºC, no growth at 10 or 45 ºC.
Grow on complex media (Trypticase soy agar with defibrinated sheep blood). Growth
does not occur in 6.5% NaCl broth.
First was isolated from bovine (skin, vagina, raw milk). Rarely isolated from human & animal clinical samples. Human isolates are
not widely accepted (3)
Doubtful pathogencity (possible urinary infections, wound infections, otitis media, pneumonia, pericarditis or meningitis). In bovines
is a normal inhabitant of the reproductive tract, but one case of metritis has been reported.
  1. 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.
  2. Holt J.G., Krieg N.R., Sneath P.H.A., Staley J.T. and Williams S.T., 1994. Bergey's Manual of Determinative Bacteriology, Ninth
    Edition, Williams & Wilkins, A Waverly Company, Baltimore, pp 527-558.
  3. Ayers S.H. &  Mudge C.S.: The streptococci of the bovine udder. Journal of Infectious Diseases, 1922, 31, 40-50.
  4. Facklam R (October 2002). "What happened to the streptococci: overview of taxonomic and nomenclature changes". Clin.
    Microbiol. Rev. 15 (4): 613–30.
  5. Takaaki AKAIKE, Moritaka SUGA, Masayuki ANDO, Yukio ANDO, Shukuro ARAKI and Ryuji FUJISE: Streptococcus acidominimus
    Infections in a Human. Japanese Journal of Medicine   Vol.27 , No.3(1988)pp.317-320 .
  6. R Higgins, S Messier, D Larochelle, M Cantin, R Bérubé, and H B Konradsen: Streptococcus acidominimus in a case of bovine
    fibrinopurulent metritis. Can Vet J. 1998 June; 39(6): 377.
  7. JEFFREY L. WATTS: Characterization and Identification of Streptococci Isolated from Bovine Mammary Glands. Journal of Dairy
    Science Vol. 71, No. 6, 1988
Positive results for esculin hydrolysis, acid production from: fructose, glucose, lactose,
sucrose & maltose. It is weakly fermentative; pH rarely decreased below 6 which makes the determination of fermentation reactions
difficult. Inulin and mannitol fermentations are delayed. Hippurate reaction is delayed.

Negative results for arginine hydrolysis, catalase, beta-mannosidase, urease, acid production from: adonitol, arabitol, arabinose,
D-cyclodextrin, dulcitol, erythritol, D- or L-fucose, methyl alpha-D-glucoside, 2- or 5-ketogluconate, gluconate, glycogen, glycerol,
inositol, lyxose, methyl alpha-D-mannoside, pullulan, raffinose, rhamnose, ribose, L-sorbose, sorbitol, starch, trehalose, D-turanose,
D- and L-xylose, xylitol & methyl beta-xyloside.
(c) Costin Stoica
Culture media
Biochemical tests
Previous page