CRITERION™ GROUP A BETA STREP AGAR BASE

Cat. no. C5110 CRITERION™ Group A Beta Strep Agar Base 84.5gm
Cat. no. C5111 CRITERION™ Group A Beta Strep Agar Base 500gm
Cat. no. C5112 CRITERION™ Group A Beta Strep Agar Base 2kg
Cat. no. C5113 CRITERION™ Group A Beta Strep Agar Base 10kg
Cat. no. C5114 CRITERION™ Group A Beta Strep Agar Base 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ Group A Beta Strep Agar Base is an enriched media for the selective isolation of group A Streptococcus (Streptococcus pyogenes) from clinical specimens.

This dehydrated culture medium is a raw material intended to be used in the making of prepared media products, which will require further processing, additional ingredients, or supplements.

SUMMARY

CRITERION™ Group A Beta Strep Agar Base is a selective media for isolation of group A streptococci from respiratory sources. This medium will inhibit most other oral flora including diptheroids, coliforms, staphylococci, Micrococcusspp., Haemophilus spp., Neisseria spp., and S. viridans. Streptococcuspneumoniae is also inhibited.

Tryptic Soy Agar is the basal medium for CRITERION™ Group A Beta Strep Agar Base. Organic nitrogen, particularly amino acids and long-chained peptides, are supplied by the combination of casein and soy peptones. This combination renders the medium highly nutritious. Osmotic equilibrium is maintained by sodium chloride. Selective agents are present in the media to suppress much of the normal respiratory flora. Sheep blood (5%) is added to facilitate growth and to detect hemolytic activity. The addition of a Bacitracin Disk (Cat. no. Z7021), 0.04 units, aids in the presumptive identification of S. pyogenes from alternative group A strains or from other PYR-positive, beta-hemolytic species.

FORMULA

Gram weight per liter: 42.2gm/L
Casein Peptone 10.0gm
Proteose Peptone 4.0gm
Sodium Chloride 5.5gm
Selective Agents 10.2mg
Agar 12.5gm

Final pH 7.3+/- 0.2 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing dehydrated culture medium at 2-30ºC. Dehydrated culture medium is very hygroscopic. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not free-flowing or if the color has changed from its original light beige.

Store the prepared culture media at 2-8ºC.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 42.2gm of the dehydrated culture media in 1 liter of distilled or deionized water. Stir to mix thoroughly.

2. Heat to boiling to dissolve completely.

3. Sterilize in the autoclave at 121ºC. for 15 minutes.

4. Cool to 45-50ºC.

5. Aseptically add 50ml of sterile defibrinated sheep blood. Stir gently while dispensing.

PROCEDURE AND INTERPRETATION OF RESULTS

For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. A72.

LIMITATIONS

Unless a provision is made to reduce oxygen tension, approximately 2% of group A streptococci may be missed if incubated aerobically. It is recommended that several stabs be made into the medium upon inoculation. (2) Incubation in increased CO 2 or anaerobically is recommended.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Streptococcus pyogenes
ATCC ® 19615
A 24hr 35°C CO 2 ** Growth with beta-hemolysis
Streptococcus mitis
ATCC ® 6249
B 24hr 35°C CO 2 ** Partial to complete inhibition
Escherichia coli
ATCC ® 25922
B 24hr 35°C CO 2 ** Partial to complete inhibition
Staphylococcus epidermidis
ATCC ® 12228
B 24hr 35°C CO 2 ** Partial to complete inhibition

** Atmosphere of incubation is enriched with 5-10% CO2.

User Quality Control

PHYSICAL APPEARANCE

CRITERION™ Group A Beta Strep Agar Base powder should appear homogeneous, free-flowing, and light beige in color. The prepared media should appear opaque, and cherry red in color.

REFERENCES

1. Anderson, N.L., et al. Cumitech 3B; Quality Systems in the Clinical Microbiology Laboratory, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.

2. Jorgensen., et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.

3. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

4. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

5. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology, J.B. Lippincott Company, Philadelphia, PA.


ATCC is a registered trademark of the American Type Culture Collection.

053116gr