RW2 (Canada)

Fungal Culture System

Dermatophyte Test Medium and Enhanced Sporulation Agar

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 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 colour change. ESA is similar to DTM but gives a green-blue colour change and promotes a more luxuriant growth of macroconedia, allowing for easier and often earlier confirmation of infection. Rapid growing species may effect a complete medium colour 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 colour change. A few organisms, including saprophytes and yeasts are capable of changing the medium from 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 plate to warm to room temperature before inoculation. As soon as possible after receipt, the specimen should be inoculated onto the DTM Agar and ESA surfaces. 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 and incubate in the dark at room temperature (25-30°C) for 10 days maximum. Incubate plates in an inverted position (lid on bottom).

For Veterinary Use Only

Interpretation

Examine plate or vial every 2-3 days for characteristic colour change and colony appearance on the DTM and ESA. The colour change (orange to red DTM, orange to blue-green ESA) must occur simultaneous with a white fluffy or white granular growth to interpret as a positive test. Most pathogenic dermatophytes will produce full colour change 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 (DTM) or blue-green (ESA), but the yeasts can be identified by their white bacteria-like colonial appearance on the DTM and ESA mediums.

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. Vials and plates in sealed bags are stable at room temperature for up to 90 days. DO NOT ALLOW VIALS OR PLATES TO FREEZE. If vials freeze they cannot be used.

Agar Formulations

On file at Shelby Scientific

Contact Information

Phone: 1.888.777.7080

Fax: 1.519.621.8778

Email: info@sensorhealth.com

www.sensorhealthvet.com

If at any time your clinic is unsure of the results of your test you can find additional information and pictures on our website. You may also contact us at Sensor Health by phone and email us test images so we may assist you with further clarification.

Presentation: 10 per box.

CPN: 2029002.0