PCR-reverse blot hybridization assay for fast and accurate identification of causative species in superficial fungal infections.

Background: Superficial fungal infections are a very common problem in dermatological clinics. The diagnostic method of fungal culture is time-consuming and has inconsistent sensitivity. Therefore, a practical method for rapid and accurate identification of the species causing superficial fungal infections is needed.

Aim: To compare PCR-reverse blot hybridization assay (PCR-REBA) with conventional fungal diagnostic methods so as to determine the reliability of PCR-REBA for the diagnosis and species identification in superficial fungal infections.

Methods: Potassium hydroxide (KOH) preparation, fungal culture, conventional real-time PCR and PCR-REBA were used to assess 83 specimens, and the results from each method were compared.

Results: Of the 83 specimens, 44 specimens that were positive by fungal culture had 62.7% agreement with PCR-REBA. Compared with real-time PCR, there was 68.7% agreement with fungal culture, but 91.6% agreement with PCR-REBA. When the comparison was made using the 55 specimens that gave positive results in both KOH preparation and fungal culture, there was 85.5% agreement with real-time PCR for fungal culture, but 94.5% agreement with PCR-REBA.

Conclusions: Compared with KOH preparation or fungal culture, PCR-REBA has higher sensitivity and specificity. Therefore, PCR-REBA could be a useful method in clinical settings because it can identify species quickly and accurately, and can also determine the existence of pathogens.