What medium would you use to isolate S. aureus the quickest?

Question

Blood agar??
PEA??
MSA??
Not sure which is the fastest, am I right in thinking blood agar is the best way to test staph?

Answer 1

blood agar is the quickest, just look for pinpoint colonies that are catalase positive.

HUGO has staph selective agar
( I dont have a link for this, its in the catalogue)


Staph Selective Agar is an agar medium used for the selective isolation and differentiation of pathogenic staphylococci. The formulation contains a lower concentration of salt (4.0%) than Mannitol Salt Agar (7.5%). The lower salt concentration enhances the growth of most staphylococci. However the addition of selective agents is required to inhibit gram-negative and non-pathogenic staphylococci. The medium also contains bromcresol purple indicator which imparts a violet color to the prepared medium. Pathogenic staphylococci produce yellow colonies surrounded by yellow zones in a violet background.
FORMULA
Gram weight per liter: 101.0gm/L
Sodium Chloride 40.0gm
Selective Agents 14.0gm
Pancreatic Digest of Casein 10.0gm
Peptic Digest of Animal Tissue 10.0gm
Mannitol 10.0gm
Beef Extract 2.0gm
Bromcresol Purple 2.0mg
Agar 15.0gm

Final pH 7.4 +/- 0.2 at 25 degrees C.

Answer 2

I'd go with the blood agar, but it's been quite a few years since I saw the inside of a clinical lab.

S. aureus does have a pretty characterisic appearance on blood agar, so it's relatively easy to know when you've got it.