Abstract:

Objective To profile genotypes of Trichophyton rubrum isolates from different body sites in patients with onychomycosis. Methods DNA was extracted from 30 T. rubrum isolates from 10 patients with onychomycosis, and subjected to PCR with tandemly repetitive subelement 1 （TRS1）-specific primer to analyze the number of repetitive elements in the non-transcribed spacer （NTS） region of ribosomal DNA gene, and to random primer amplification with the random primer OPAA11. The genotype variety was evaluated for T. rubrum isolates from different body sites of patients with onychomycosis. Results All the strains were classified into 5 genotypes based on the copy number of TRS1, and into 11 genotypes by RAPD analysis. The genotypes of T. rubrum seemed unrelated to sites of infection. Genotype diversity was observed among T. rubrum strains from different body sites of the same host in 7 out of the 10 cases as shown by amplification of TRS1 region, in 8 out of the 10 cases as demonstrated by RAPD analysis. Conclusion A single host with onychomycosis could harbor multiple genotypes of T. rubrum at different body sites, suggesting external sources of infection rather than infection from a different site in the same individual.

Key words: Trichophyton rubrum, Molecular strain typing, Random amplification of polymorphic DNA, Tinea, Onychomycosis