The Preservation of Dermatophytes at Sub-Freezing Temperatures

Abstract

Pleomorphism of dermatophyte cultures has always been a problem particularly when they are needed for teaching purposes. In this paper we have presented the results of our work involving the storage at sub-freezing temperatures of 12 species of Epidermophyton, Microsporum and Trichophyton, with a total of 61 isolates. They were stored for varying periods of time up to 2 years. Bits of growth from each culture were transferred to tubes containing 1.5 ml of human plasma and 1.5 ml of litmus milk. These were stored at the arbitrary temperatures of -22[degree]C and -52[degree]C. As needed, frozen preparations were thawed, a few loopfuls of each trans-ferred to a Sabouraud''s dextrose agar slant and incubated at 28[degree]C. With this procedure it was possible to maintain typical cultures free from pleomorphic changes.