Biochemical Test and Identification of Staphylococcus aureus


­Basic Characteristics Properties (Staphylococcus aureus)
Capsule Non-Capsulated
Catalase Positive (+ve)
Citrate Positive (+ve)
Coagulase Positive (+ve)
Gas Negative (-ve)
Gelatin Hydrolysis Positive (+ve)
Gram Staining Positive (+ve)
H2S Negative (-ve)
Hemolysis Positive (+ve)- Beta
Indole Negative (-ve)
Motility Negative (-ve)
MR (Methyl Red) Positive (+ve)
Nitrate Reduction Positive (+ve)
OF (Oxidative-Fermentative) Fermentative
Oxidase Negative (-ve)
Pigment Mostly Positive (+ve)
PYR Negative (-ve)
Shape Cocci
Spore Non-Sporing
Urease Positive (+ve)
VP (Voges Proskauer) Positive (+ve)
Fermentation of
Arabinose Negative (-ve)
Cellobiose Negative (-ve)
DNase Positive (+ve)
Fructose Positive (+ve)
Galactose Positive (+ve)
Glucose Positive (+ve)
Lactose Positive (+ve)
Maltose Positive (+ve)
Mannitol Positive (+ve)
Mannose Positive (+ve)
Raffinose Negative (-ve)
Ribose Positive (+ve)
Salicin Negative (-ve)
Sucrose Positive (+ve)
Trehalose Positive (+ve)
Xylose Negative (-ve)
Enzymatic Reactions
Acetoin Production Positive (+ve)
Alkaline Phosphatase Positive (+ve)
Arginine Dehydrolase Positive (+ve)
Hyalurodinase Positive (+ve)
Lipase Positive (+ve)
Ornithine Decarboxylase Negative (-ve)

18 thoughts on “Biochemical Test and Identification of Staphylococcus aureus”

  1. Disregard the comments stating MR and VP test cannot both be positive. The fact of the matter is that they absolutely can both be positive. There are a number of organisms positive for both including: Proteus myxofaciens, Enterobacter intermedium, Klebsiella planticola and Serratia liquefaciens. Those stating otherwise please review the literature before commenting.

    • Depends on the culture – Like if u use EMB media it will give a metallic sheen and if u use MLA it will give pink coloured colonies because of Lactose fermentation.

  2. how can MR test and VP test both be positive. if one is positive ,other has to be
    negative and vice versa . both can be negative, but both tests can never be positive.

  3. Sagar sir, I am Amit khanal from B.Sc. Microbiology 4th year, St.Xavier’s college. I happened to be doing a practical homework on Enzymatic Activities of bacteria- one of which included COAGULASE TEST. After going through some of the literatures, including the (prescribed)college book itself; I found the lines:
    1. Coagulase reacting factor—abbreviated as CRF—which in your site has been abbreviated as CRP
    2. Tube test for coagulase tests both BOUND AND FREE COAGULASE.. mentioned only free coagulase on this site.

    Could you shed some light in this ?

    Thanks a lot

  4. Hi, may i know what are the possible reasons as to why does s. aureus gives of positive result in Ornithine decarboxylase? thank you!

  5. S. aureus is historically regarded as a non-motile organism. More recently it has been shown that S. aureus can passively move across agar surfaces in a process called spreading. Discovered that S. aureus can spread across the surface of media in structures that we term ‘comets’.

  6. Dear Sagar,
    Can I have a question?
    How can I do Bacitracin Susceptibility test for Staphylococci identification?
    Thank you for your help.
    Best regards.

    • Use Bacitracin Taxo A (0.04IU) as we did to identify S.pyogenes.
      Diameter zone: S>=10mm, R<=9mm if I not mistaken (kindly refer Koneman's Book)

      Used to differentiate between Staphylococcus, Micrococcus and Macrococcus
      Staphylococcus/Macrococcus: Bacitracin resistant
      Micrococcus: Bacitracin sensitive

      To differentiate between Staphylococcus/Macrococcus, we can do glucose fermentation under anaerobic condition whereas Staphylococcus able to ferment glucose anaerobically (positive) whiles Macrococcus not able to ferment glucose anaerobically (negative). Micrococcus also not able to ferment glucose anaerobically (negative)

      • above mentioned tests are used for confirmation of the Staphylococcus aureus. but first, you need to identify it by colony morphology then gram staining, microscopy, then catalase and oxidase test. when all of these test confirmed then apply above mentioned biochemical tests.

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