[Comparative study between culture and PCR-RFLP analysis on identification of the causative agent of Tinea Unguium].

BACKGROUND

To identify the pathogenic fungi of dermatophytosis, restriction fragment length polymorphism (RFLP) analysis of PCR amplified ribosomal DNA including internal transcribed spacers (ITS) has been established in Japan. Our purpose was to evaluate the usability of PCR-RFLP analysis to identify the causative agent of tinea unguium directly from a nail sample.

METHOD: Samples of tinea unguium from 100 nails were collected and cultured on Sabouraud's glucose agar and observed for 2 months. DNA was extracted from these samples, and the PCR product was digested with restriction enzymes Mva I and Hinf I. Weight of the samples was determined.

RESULT: Sensitivity of PCR-RFLP analysis (73%) was higher than that of culture (20%) showing that PCR is more advantageous for identification of the causative agent of tinea unguium. Sensitivity of PCR-RFLP did not depend on weight of the nail sample.