Correlation between multilocus genotype, clinical picture and morphology of Trichophyton interdigitale / T. mentagrophytes isolates
Trichophyton interdigitale is one of the most common agents of tinea pedis and onychomycosis in humans. The closely related species T. mentagrophytes is primarily the agent of superficial infections in animals (e.g. rabbits, cats and dogs), but it also commonly causes zoonotic infections in humans, especially tinea corporis. Due to the differences in the source of infections and the clinical manifestation, the differentiation of these species is clinically and epidemiologically significant. Based on the original concept, these species should be distinguishable by characteristic phenotypic features, including macromorphology of colonies, presence/absence of macroconidia and spiral hyphae, etc. However, other recent studies have indicated that the correlation between the clinical picture of infection and phenotype and genotype of the pathogen is not so clear as expected. Due this, the differentiation of these taxa mostly relies on the several substitutions in the internal transcribed spacer region (ITS).
The aim of this study was to examine the correlation between multilocus genotype, clinical picture and morphology of T. interdigitale / T. mentagrophytes. For this purpose, a total of 120 isolates were obtained from Czech patients with various clinical manifestations of dermatophytosis (tinea pedis, corporis and unguium). An analysis of micro- and macromorphology, and physiology was performed together with molecular characterisation of the strains by DNA sequences from three loci: ITS, β-tubulin and translation elongation factor 1-α (TEF). The mating-type genes were also characterised. A recombination analysis was performed to identify recombining lineages. Statistical analysis of the association of the mentioned features with recombining lineages was performed. The results of several species delimitation methods were compared.