Conventional and molecular characterization of Trichophyton rubrum

Abstract

Different studies illustrated that Trichophyton rubrum, among all species of Trichophyton, is the most prevalent and consequently the most important genus. T. rubrum as a worldwide filamentous pathogen fungus can infect human keratinized tissue (skin, nails and rarely hair), and causes dermatophytosis. Researchers use two general methods for the identification of dermatophytes namely, conventional methods on the basis of phenotype variations and molecular methods on the basis of molecular differences. Due to some limitations in traditional methods, in the recent years, molecular biological methods are regarded as useful in the exact and rapid recognition of dermatophytes. The present study identified nine clinical isolates and one ATCC as a control strain of T. rubrum by using both conventional and molecular methods. The molecular systematics method was used to elucidate genetic diversity among strains of T. rubrum and withinTrichophyton species. Morphological characteristics of all colonies T. rubrum quite varies among each other; we revealed that that conventional methods are generally prolonged and may be indecisive. However, molecular studies based on internal transcribed spacer(ITS) sequencing provides a very accurate result, which is more than 96% the similarity ofT. rubrum among all isolates, and more than 90% similarity within Trichophyton spp. Key words: Trichophyton rubrum, conventional method, internal transcribed spacer (ITS) regions, identification, dermatophytes.