IDENTIFICATION OF COMMON DERMATOPHYTES (TRICHOPHYTON, MICROSPORUM, EPIDERMOPHYTON) USING POLYMERASE CHAIN-REACTIONS

Polymerase chain reaction (PCR) fingerprinting detected DNA polymorphi sms among frequently isolated species and strains of the genera Tricho phyton, Microsporum and Epidermophyton. The patterns generated by this DNA-based method permitted species and strains to be identified, The conventional methods to identify dermatophytes rely on the expression of characteristic morphological features, as well as several physiolog ical properties. Identification is often delayed or problematic becaus e isolates may be slow to form conidia or produce atypical microscopic structures or colony appearances. Using non-specific primers such as (AC)(10), (GTG)(5), M13 core sequence and AP3, characteristic PCR prof iles were generated for 17 species, Intraspecies variables were also o bserved for four of six varieties of T. mentagrophytes, whereas no det ectable DNA variability tvas found within the three varieties of T. to nsurans. Comparing species-specific PCR fingerprints of clinical isola tes with those of type strains, species could be identified by their P CR fingerprints, even if they could not be identified by the accepted phenotypic characteristics.