CHROMagar™ StrepA

For screening of Group A Streptococci in throat samples

Order References

Please use these references when
contacting your local distributor :

5000 mL Pack …………. SP372

Included : base SP372(B) + supplements SP372(S1) + SP372(S2)

25 L Pack ……………… SP373-25

Included : base SP373-25(B)+ supplements SP373-25(S1) + SP373-25(S2)


Colonies Appearance

Group A Streptococcus

Orange to rouge

Other oral Streptococci

Colourless or blue


Streptococcus pyogenes infection is responsible for nearly all Streptococci caused bacterial pharyngitis, therefore the specific target of current strep throat screening methods.

Rapid and accurate detection of this microorganism in throat specimens, particularly in children and elderly patient, is essential to start antibiotic therapy, to prevent complications and reduce the risk of transmission to other persons.

Patients are commonly tested for the presence of GAS using antigen detection test that provide results in 15-20 minutes, but with a positive predictive value of ~70-90 % and a rate of false negatives ~10-20 %. However, throat culture is used primarily as a confirmatory test with definitive results requiring 24 h.

CHROMagar™ StrepA is a new chromogenic formulation allowing for an easy to read and straight forward color differentiation of GAS colonies (in orange to red) among the other bacteria in the complex throat flora (colorless or blue colonies).

1.  First chromogenic medium designed for the detection of S. pyogenes.

4.  High specificity : Differentiation of GAS in orange colonies from the other oral Streptococci which grow in blue or colourless colonies.

2.  Easy interpretation : Easier reading thanks to an intense orange to red colony colouration.

3.  High sensitivity : Detection of GAS strains with a sensitivity close to 100 %.


Technical Documents

To download the certificate of analysis, please indicate your lot number below:

Scientific Publications