Fungassay

DERMATOPHYTE TEST MEDIUM

FUNGASSAY Dermatophyte Test Medium is a culture medium that provides the veterinarian with a simple, rapid and practical method for confirming diagnosis of dermatophyte infections. The test is based on a color change within the medium from amber to red¹, caused by the growth of pathogenic fungi, such as Microsporum and Trichophyton species. These fungi cause most of the dermatomycoses in veterinary medicine.

Directions For Use:

For optimum results, it is necessary to follow the directions given below.

1. Washing is indicated only in cases of heavy contamination or encrustation.^2,3 If the site is washed prior to sampling, a non-medicated, non-fungicidal soap is recommended, followed by drying with an absorptive material. These steps remove saprophytic organisms which could overgrow the culture, thus masking the growth of pathogenic fungi.

2. Select hair and scales for culture from both the periphery and the center of the lesion. Broken, frayed or distorted hairs and those that fluoresce with Wood’s light are the best specimens.

3. Remove only a small portion of hair and scales from the lesion with a hemostat or thumb forcep. Avoid placing large amounts of hair and scales on the medium: this will produce useless overgrowth of contaminants.

4. When removing the cap from the FUNGASSAY Dermatophyte Test Medium bottle, take care to avoid contamination.

5. Press the hair and scales on the culture medium to assure good contact, but do not bury the specimen in the medium.

6. When replacing the cap, make certain that it remains loose so that air exchange can occur in the bottle during incubation. When the cap is too tight color change will not develop.

7. Identify the bottle with patient and date.

8. Incubate at room temperature (75-85°F, 22-29°C) so that suitable growth will occur.

9. Evaluation of the test results can begin as early as 48 hours after inoculation. A pinkish color will appear in the amber medium under the specimen and developing colony. The color will intensify as growth proceeds and is due to the alkaline metabolites produced by the dermatophytes. When a positive dermatophyte infection is present, the entire medium will turn red by the seventh to fourteenth day. If there is no growth within ten days, redistribute the sample on the medium. Occasionally growth does not occur due to improper inoculation.

10. A color change may occasionally be produced by a specimen heavily contaminated with saprophytic fungi or bacteria.¹ However this is not a problem because differentiation from dermatophytes can be made as follows:

Dermatophyte: A color change appears in the medium with colony growth - colony pigments are usually light colored.

Saprophytic fungi: Colony growth is well established before any color change appears in the medium - colony pigments are usually dark colored.

Bacteria: The morphology of bacterial colonies differs from the morphology of fungal colonies.

*at 14 days

Precautions:

Refrigerate FUNGASSAY Dermatophyte Test Medium for optimal storage. Warming to room temperature before using is not necessary.

Destroy the used FUNGASSAY Dermatophyte Test Medium bottle by incineration to eliminate spread of all organisms.

How Supplied:

FUNGASSAY Dermatophyte Test Medium is supplied in a package containing 10 individual bottles.

CAUTION:

Keep out of reach of children

For Veterinary Use Only

References

1. Taplin, D., Zaias, N., Rebell, G. and Blank, H.: Isolation and recognition of dematophytes on a new medium (DTM). Arch. Derm. 99:203-209 (1969).

2. Blakemore, J.C. Diagnosis of dermatophyte infection - part 1. The Practicing Veterinarian 46(6): 15-22 (1974).

3. Carroll, H. F. Evaluation of dermatophyte test medium for diagnosis of dermatophytosis. J. Am. Vet. Med. Assn. 165(2): 192-195 (1974).

Zoetis Inc., 16420 Via Esprillo, San Diego, California 92127 USA

40023463

CPN: 1115009.4