Staphylococcus intermedius
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Bacilli, Order Bacillales, Family Staphylococcaceae, Genus Staphylococcus, Staphylococcus intermedius  
Hajek 1976. Historical synonym:
Staphylococcus aureus var. canis  Meyer 1966.
Gram-positive cocci, 0.5-1.5 μm in diameter, nonmotile, nonsporing, occuring singly
or grouped in pairs and clusters.
White-cream, 5-6.5 mm diameter, S-type colonies. Facultatively anaerobic. Optimum
growth temperatature is 37 ºC (also grow at 15 & 45 ºC). Can grow on Trypticase Soy
Agar ± 5% sheep blood, Trypticase Soy Broth, Chapman agar, P agar.
Bacteria was isolated from horse, dog, cat, mink, rat, mouse, pigeon & other birds (from skin, nose, pharynx, ears, conjunctive,
vagina, intestine). Frequent inhabitant of dog skin and can be transferred to the skin of human handlers. Rarely was isolated from
humans. Sensible to novobiocin and lysostaphin. Resistant to lysozyme.
In animals: dermatitis, otitis, conjunctivitis, urinary infections, pneumonia, abscesses, peritonitis, mastitis. Exfoliative toxin involved in
dermatitis. May be a normal resident in the canine  nasal cavity, oropharynx, and the perianal region. In humans may produce wound
infections (dog bite infections), food poisoning (enterotoxins A, B, C, D, E). Opportunistic pathogen in immunocompromised patients.
  1. Holt J.G., Krieg N.R., Sneath P.H.A., Staley J.T., Wiliams S.T., 1994. Bergey's Manual of Determinative Bacteriology, Ninth Edition,
    Williams & Wilkins, Baltimore. Group 17, Gram-Positive Cocci, 527-558.
  2. Hajek V.: Staphylococcus intermedius, a new species isolated from animals. International Journal of Systematic Bacteriology,
    1976, 26, 401-408.
  3. Devriese L.A. & Hajek V. : Identification of pathogenic staphylococci isolated from animals and foods derived from animals. J.
    Appl. Bacteriol., 1980, 49, 1-11.
  4. Karsten Becker, Birgit Keller, Christof von Eiff, Michaela Brück, Gabriele Lubritz, Jerome Etienne, & Georg Peters: Enterotoxigenic
    Potential of Staphylococcus intermedius. Applied and Environmental Microbiology, December 2001, p. 5551-5557, Vol. 67, No. 12.
  5. Karl-Heinz Schleifer and Julia A. Bell, 2009. Family VIII. Staphylococcaceae fam. nov.. 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, 392-426.
Positive results for nitrate reduction, alkaline phosphatase, urease, heat-stable
nuclease, gelatinase, coagulase-rabbit plasma, deoxyribonuclease, catalase, methyl
red test, acid production from: trehalose, fructose, glucose, glycerol, sucrose & ribose.

Negative results for oxidase, hyaluronidase, fibrinolysin, beta-glucuronidase, acetoin production, esculin hydrolysis, indole
production,  H
2S, protein A, tellurite reduction, acid production from: xylitol, raffinose, xylose, arabinose, cellobiose, fucose, salicin &

Variable results for clumping factor, beta-galactosidase, beta-glucosidase, arginine dihydrolase, coagulation of human plasma,
hemolysin, acid production from: lactose, mannitol & turanose.

API Staph kit cannot identify Staphylococcus intermedius.  If you are getting the message  <<Staphylococcus aureus  …. possibility of S. intermedius if of
veterinary origin>>  and your sample is harvested from an animal it doesn’t mean that the strain is automatically
S. intermedius. You need to perform
additional tests to confirm. (Admin note)
(c) Costin Stoica
Species is biochemically close to  Staphylococcus pseudintermedius
Culture media
Biochemical tests
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