MYCOBIOTIC AGAR

Cat. no. W50 Mycobiotic Agar, 15x100mm Plate, 26ml 10 plates/bag
Cat. no. L45 Mycobiotic Agar, 20x125mm Tube, 10ml Slant 20 tubes/box
Cat. no. X30 Mycobiotic Agar, 50ml HardyFlask™, 12ml Slant 20 flasks/box

INTENDED USE

Hardy Diagnostics Mycobiotic Agar is recommended for use in the isolation of pathogenic fungi from clinical specimens.

SUMMARY

Leach, Ford and Whiffen described the use of cycloheximide for the inhibition of saprophytic fungi. (5,7) Cooke, et al., employed the use of chloramphenicol to various media to inhibit bacterial growth. (1,6) Researchers later found that the addition of both cycloheximide and chloramphenicol achieved more complete selectivity against growth of saprophytic fungi and bacteria. (8,9) The incorporation of both these antimicrobics in the soybean basal medium of Mycobiotic Agar provides selectivity to the medium.

Mycobiotic Agar is a selective medium consisting of peptones, dextrose, cycloheximide and chloramphenicol. The basal medium is soybean meal. Peptones from soybean meal provide the nutritive properties necessary for growth. Dextrose serves as the energy source. Cycloheximide inhibits most saprophytic fungi while chloramphenicol acts as a broad-spectrum antimicrobic. Chloramphenicol inhibits a wide variety of gram-positive and gram-negative bacteria.

FORMULA

Ingredients per liter of deionized water:*

Pancreatic Digest of Soybean Meal 10.0gm
Dextrose 10.0gm
Cycloheximide 0.4gm
Chloramphenicol 0.05gm
Agar 15.5gm

Final pH 6.5 +/- 0.3 at 25ºC.

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

STORAGE AND SHELF LIFE

Storage: Upon receipt store Mycobiotic Agar plates (Cat. no. W50) at 2-8ºC. Products L45 and X30 should be stored at 2-30ºC Products should not be used if there are any signs of contamination, deterioration (shrinking, cracking, or discoloration) or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.

PRECAUTIONS

PROCEDURE

Specimen Collection: Specimen should be inoculated onto medium as soon as possible after receipt. Streak so as to obtain isolated colonies. Consult listed references for information on specimen collection.

Method of Use: A non-selective medium should be inoculated along with the selective medium for isolation of fungi from potentially contaminated specimens. Incubate medium at 25-30ºC. Two sets of media should be inoculated for isolation of fungi causing systemic mycoses. One set should be incubated at 25-30ºC. and the second set at 35ºC. Examine weekly and observe for growth and typical colonial morphology. Cultures should be held for 4 to 6 weeks before being reported as negative.

INTERPRETATION OF RESULTS

Consult listed references for the interpretation of growth and other identification tests to identify growth of organism in this medium.(13-15)

LIMITATIONS

It is recommended that macroscopic and microscopic morphology of isolates in pure culture be examined. Further biochemical tests may be necessary for complete identification. For more information, see appropriate references.

The antimicrobics in this medium may result in the inhibition of some pathogenic fungi. It is recommended that a non-selective media be set-up in parallel for optimum recovery.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Trichophyton mentagrophytes
ATCC ® 9533
G 7 days 15-30°C Aerobic Growth
Candida albicans
ATCC ® 10231
A 7 days 15-30°C Aerobic Growth
Escherichia coli
ATCC ® 25922
B 7 days 15-30°C Aerobic Partial to complete inhibition
Aspergillus brasiliensis
ATCC ® 16404
G 7 days 15-30°C Aerobic Partial to complete inhibition

User Quality Control

Physical Appearance

Mycobiotic Agar should appear slightly opalescent, and light amber in color.


T. mentagrophytes growing on Mycobiotic Agar

Trichophyton mentagrophytes (ATCC ® 9533) growing on Mycobiotic Agar (Cat. no. W50). Incubated aerobically for 5 days at 30ºC.

C. albicans growing on Mycobiotic Agar

Candida albicans (ATCC ® 10231) growing on Mycobiotic Agar (Cat. no. W50). Incubated aerobically for 2 days at 30ºC.

Mycobiotic Agar

Uninoculated plate of Mycobiotic Agar (Cat. no. W50).

REFERENCES

1. Antibiotics and Chemotherapy, 4:657, 1954.

2.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.

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. J. Am. Chem. Soc.; 69:474, 1947.

6. J. Am. Med. Assoc.; 160:537, 1956.

7. J. Bacteriology; 56:283, 1948.

8. J. Chron. Dis.; 5:545, 1957.

9. J. Lab. and Clin. Med.; 55:116, 1960.

10. MacFaddin, J.F. Biochemical Tests for Identification of Medical Bacteria,, Lipincott Williams & Wilkins, Philadelphia, PA.

11. Versalovic, J., et al. Manual of Clinical Microbiology. American Society for Microbiology, Washington, D.C.

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

13. Kwon-Chung, K.J., and J.E. Bennett. 1992. Medical Mycology. Lea and Febiger, Malvern, PA.

14. Larone, D.H. Medically Important Fungi: A Guide to Identification, American Society for Microbiology. Washington, D.C.

15. St. Germain, Guy, et al. 1996. Identifying Filamentous Fungi. Star Publishing Company, Belmont, CA.


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

032816gr