Discrimination of Trichophyton tonsurans and Trichophyton equinum by PCR-RFLP and by β-tubulin and translation elongation factor 1-α sequencing

Med Mycol. 2012 Oct;50(7):760-4. doi: 10.3109/13693786.2012.661885. Epub 2012 Feb 28.

Abstract

Trichophyton tonsurans and T. equinum are two closely related sister species of dermatophytes, but differ in their preferred hosts, i.e., humans or horses, respectively. Routine procedures for their identification depend on studies of their phenotypic, physiological and biochemical characteristics, which are laborious and may yield ambiguous results. Molecular methods using rDNA ITS also had been judged to be insufficiently discriminatory. In the present study two genetic markers were sequenced in addition to the ITS region, i.e., partial β-tubulin (BT2) and translation elongation factor 1-α (TEF1). The TEF1 locus revealed a consistent differences in a 13 bp indel and an additional SNP between the two species, along with a single base substitution in BT2 and one ITS1, enabling unambiguous distinction of the two taxa. RFLP targeting the ITS region was evaluated as a potential tool for routine screening of suspected isolates of T. tonsurans and T. equinum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • DNA, Fungal / chemistry
  • DNA, Fungal / genetics*
  • DNA, Ribosomal Spacer / chemistry
  • DNA, Ribosomal Spacer / genetics
  • Humans
  • INDEL Mutation
  • Molecular Sequence Data
  • Mycology / methods*
  • Peptide Elongation Factor 1 / genetics*
  • Polymorphism, Restriction Fragment Length*
  • Polymorphism, Single Nucleotide
  • Sequence Analysis, DNA*
  • Trichophyton / classification*
  • Trichophyton / genetics
  • Tubulin / genetics*

Substances

  • DNA, Fungal
  • DNA, Ribosomal Spacer
  • Peptide Elongation Factor 1
  • Tubulin