Development of a novel polymerase chain reaction-enzyme-linked immunosorbent assay for the diagnosis of Trichophyton rubrum onychomycosis

Br J Dermatol. 2013 Jun;168(6):1236-42. doi: 10.1111/bjd.12221.

Abstract

Background: The prevalence of onychomycosis has increased steadily in the past decade. An accurate diagnosis at the outset is important for successful and cost-effective treatment of patients. However, current diagnostic tests for onychomycosis are not rapid, sensitive or specific.

Objectives: To develop a microsatellite-based polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (MS-ELISA) for the detection of Trichophyton rubrum, which is the most common aetiological agent of onychomycosis.

Methods: An archival set of 434 nail and skin specimens from 217 patients was included as the test sample in this study. We also compared MS-ELISA with an earlier published topoisomerase PCR-ELISA (TI-ELISA) using template DNA extracted by another method.

Results: The MS-ELISA detected the highest number of positive samples (69%) followed by direct microscopy (56%), TI-ELISA (44%) and fungal culture (30%). When an identical DNA extraction method was applied to 120 specimens, the MS-ELISA proved to be twice as sensitive as the TI-ELISA.

Conclusions: We have optimized a target gene and DNA extraction method for rapid detection of T. rubrum onychomycosis.

MeSH terms

  • Antibodies, Fungal / blood
  • DNA, Fungal / analysis
  • Enzyme-Linked Immunosorbent Assay / methods*
  • False Positive Reactions
  • Humans
  • Onychomycosis / diagnosis*
  • Onychomycosis / microbiology
  • Polymerase Chain Reaction / methods*
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Trichophyton / genetics
  • Trichophyton / immunology
  • Trichophyton / isolation & purification*

Substances

  • Antibodies, Fungal
  • DNA, Fungal