Dermatophyte test kit

Fungal culture-system

Dermatophyte test medium

For veterinary use only

keep out of reach of children

Introduction

This fungal culture system is designed to provide a simple and comprehensive analysis of the pathogenic fungus that cause most fungal infections seen in the clinical practice of veterinary medicine.

History/Summary

DTM is a preferred medium for isolation and early detection of members of Microsporum, Trichophyton, and Epidermophyton genera by means of the distinct color change. Rapid growing species may effect a complete medium color change in as few as 2 -3 days. The slower growing species will change the indicator in proportionately longer time periods. Other organisms may grow on DTM but can be recognized as non dermatophytes by the absence of color change. A few organisms, including saprophytes and yeasts are capable of changing the medium form orange to red, but they are easily recognized by their distinctive colonial morphology.

Specimen collection

Sample collection (critical to successful culturing of dermatophytes): Samples can be collected from any animal species with a suspected dermatophyte infection. the site should be cleaned if grossly contaminated. Soap and water may be used gently to avoid mechanical removal of infected material. A gauze sponge soaked in 70% alcohol may be laid over the sample site for 30 seconds or wiped gently over the site. Let the site dry before collecting sample. Clean forceps and/or scalpel may be used to obtain infected hairs, skin scales and crusts. The periphery of active lesions is the best area to obtain the samples. Fluorescing hairs and skin fragments observed under a Wood’s lamp are excellent specimens.

Procedure

Allow vial or plate to warm to room temperature before inoculation. As soon as possible after receipt, the specimen should be inoculated onto the DTM Agar surface. Transfer specimen to agar surface and gently implant specimen in the surface of the agar. Specimens may contain fragments of skin, nails, hair, pus, etc.

Replace lid on plate or cap vial loosely and incubate in the dark at room temperature (25-30°C) for 14 days maximum. Incubate plates in an inverted position. (Lid on Bottom)

Interpretation

Examine plate or vial after 2-3 days and every day there after for characteristic color change on DTM and colony appearance. The orange to red color change must occur simultaneous with a white fluffy or white granular growth to interpret as a positive test. Most pathogenic dermatophytes will produce full color change from orange to red in 3-6 days on the DTM medium while most saprophytic fungi and bacteria are inhibited. Certain strains of yeast (Candida albicans) are capable of converting the indicator to red, but the yeasts can be identified by their white bacteria like colonial appearance on the DTM medium.

Common Dermatophytes

Limitations

The complete classification of dermatophytes depends upon microscopic observations of direct and slide culture preparations along with physiological and serological tests.

Storage

Store vials or plates at 2-8°C (36-46°F). Vials, and plates in sealed bags are stable at room temperature for up to 90 days. DO NOT ALLOW PLATES OR VIALS TO FREEZE. If vials freeze, they cannot be used.

Agar formulations

On file at Shelby Scientific

See container for lot number and expiration date.

Questions? (855) 724-3461

Distributed by: Covetrus North America, 400 Metro Place North, Dublin, OH 43017

covetrus.com

AH-Dermatophyte kit-02

REV: 1219

CPN: 2050037.0