Application of PCR to the identification of dermatophyte fungi

Infection of the keratinised tissues (skin, hair and nails) in man and anim als by keratinophilic fungi (dermatophytes) results in dermatophytosis (als o known as tinea or ringworm). As conventional laboratory procedures for th e identification of dermatophytes are either slow or lack specificity, impr oved diagnostic methods are required. The application of nucleic acid ampli fication technology has made rapid and precise identification of dermatophy tes possible. Recent studies have shown that when one of the four random pr imers (OPAA11, OPD18, OPAA17 and OPU15) was used in arbitrarily primed PCR (AP-PCR), up to 20 of the 25 dermatophyte species or subspecies under inves tigation could be distinguished on the basis of characteristic band pattern s detected in agarose gel electrophoresis. A combination of two random prim ers (OPD18 and OPAA17) used in separate reaction tubes identified 23 of the 25 dermatophyte species or subspecies examined. AP-PCR provides a rapid an d practical tool for identification of dermatophyte isolates that is indepe ndent of morphological and biochemical characteristics and thus enhances la boratory diagnosis of dermatophytosis.