CRITERION™ SabHI AGAR BASE

Cat. no. C6790 CRITERION™ SabHI Agar Base 118gm
Cat. no. C6791 CRITERION™ SabHI Agar Base 500gm
Cat. no. C6792 CRITERION™ SabHI Agar Base 2kg
Cat. no. C6793 CRITERION™ SabHI Agar Base 10kg

INTENDED USE

Hardy Diagnostics CRITERION™ SabHI Agar Base is recommended for use as a general purpose growth medium in qualitative procedures for the isolation and cultivation of dermatophytes and other pathogenic and nonpathogenic fungi from clinical and nonclinical samples.This medium may be enriched with blood to promote the growth of more fastidious microorganisms or it may be made selective by incorporating the use of antimicrobial agents.

Dehydrated culture media is a raw material not intended for use in the diagnosis of human disease. For implementation, this product requires additional processing and supplementation of ingredients before use.

SUMMARY

Sabouraud designed Sabouraud Dextrose Agar for the cultivation of dermatophytes.(9)  It is a general purpose medium used in qualitative procedures for the cultivation of dermatophytes and other pathogenic and non-pathogenic fungi from clinical and non-clinical specimens. Brain Heart Infusion Agar is used for the primary isolation and cultivation of fungi from clinical specimens.(2) In 1967, Gorman combined the two media to produce SabHI Agar, and the combined formulation is superior for the recovery of pathogenic fungi than either medium on its own.(8)

The peptones and brain heart digest in CRITERION™ SabHI Agar Base provide essential amino acids, nitrogen, sulfur, carbon and trace minerals. Dextrose provides an energy source for metabolism. Sodium chloride is an essential electrolyte, whereas disodium phosphate acts as a pH buffer. Defibrinated sheep blood can be added to the medium to provide essential growth factors for more fastidious, dimorphic fungil. Gorman demonstrated increased recovery of H. capsulatum when the medium was supplemented with blood.(8) Blood also aids in the conversion of H. capsulatum and B. dermatitidis to the yeast phase.

CRITERION™ SabHI Agar Base can be made selective by the incorporation of chloramphenicol, cycloheximide and gentamicin. Chloramphenicol inhibits a range of gram-positive and gram-negative bacteria; cycloheximide inhibits saprophytic molds but may also inhibit the growth of some significant pathogens (e.g., Cryptococcus neoformans, some Candida species, some Aspergillus spp. and mucormycetes (formally zygomycetes)); gentamicin inhibits the growth of most gram-negative bacteria.

FORMULA*

Gram weight per liter: 59.0gm/L
Dextrose 21.0gm
Brain Heart Infusion 10.0gm
Meat Peptone 7.25gm
Casein Peptone 2.25gm
Sodium Chloride 2.5gm
Disodium Phosphate 1.25gm
Agar 15.0gm

Final pH 7.0 +/- 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 and will clump when exposed to moisture and air. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. Dehydrated culture media should be discarded if clumped, if the media is not free-flowing or if the color has changed from its original light beige.

Store the prepared culture media at 2-8ºC and do not remove the container desiccant, if applicable.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 59.0gm of the dehydrated culture media in one liter of distilled or deionized water. Stir to mix thoroughly.

2. Heat to boiling for one minute to dissolve completely. Do not overheat.

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

4. Cool to 45-50ºC and dispense as desired.*

5. Aseptically pour desired volume into sterile containers.

* Note: Additional selective ingredients and/or blood may be aseptically added prior to dispensing media into desired sterile containers.

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. W75.

LIMITATIONS

For the proper identification of fungi, microscopic examination and evaluation of morphological structures is required. Further biochemical, physiological, serological tests and microscopic morphology of pure cultures are recommended for complete identification. For more information see appropriate references.

For selective media, specific strains of fungi for which the medium is designed to isolate often may be inhibited. Fungi for which the medium is designed to inhibit may grow.

A non-selective and selective medium should be inoculated for isolation of fungi from potentially contaminated specimens.

Accurate counting may be difficult with molds or spreading colonies.

Rare, fastidious microorganisms may not grow on selective media formulations

MATERIALS REQUIRED BUT NOT PROVIDED

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

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Candida albicans
ATCC ® 60193
A 24-48hr 35°C Aerobic Growth
Trichophyton mentagrophytes
ATCC ® 9533
G 7 days 15-30°C Aerobic Growth

User Quality Control

Physical Appearance

CRITERION™ SabHI Agar Base powder should appear homogeneous, free-flowing, and light beige in color. The prepared media should appear slightly opalescent, and amber 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. Versalovic, J., 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. Cumitech 11: Practical Methods for Culture and Identification of Fungi in the Clinical Microbiology Laboratory. 1980. American Society for Microbiology, Washington, D.C.

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

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

7. Quality Assurance for Commercially Prepared Microbiological Culture Media, M22. Clinical and Laboratory Standards Institute (CLSI - formerly NCCLS), Wayne, PA.

8. Gorman, J.W. 1967. Am. J. Med. Technol.; 33:151.

9. Sabouraud. 1892. Ann. Dermatol. Syphil.; 3:1061.


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

051316gr