Reconstruction of phylogenetic relationships in dermatomycete genus Trichophyton Malmsten 1848 based on ribosomal internal transcribed spacer region, partial 28S rRNA and beta‐tubulin genes sequences

Abstract

Trichophyton spp. are important causative agents of superficial mycoses. The phylogeny of the genus and accurate strain identification, based on the ribosomal ITS region sequencing, are still under development. The present work is aimed at (i) inferring the genus phylogeny from partial ITS, LSU and BT2 sequences (ii) description of ribosomal ITS region polymorphism in 15 strains of Trichophyton interdigitale. We performed DNA sequence-based species identification and phylogenetic analysis on 48 strains belonging to the genus Trichophyton. Phylogenetic relationships were inferred by maximum likelihood and Bayesian methods on concatenated ITS, LSU and BT2 sequences. Ribosomal ITS region polymorphisms were assessed directly on the alignment. By phylogenetic reconstruction, we reveal major anthropophilic and zoophilic species clusters in the genus Trichophyton. We describe several sequences of the ITS region of T. interdigitale, which do not fit in the traditional polymorphism scheme and propose emendations in this scheme for discrimination between ITS sequence types in T. interdigitale. The new polymorphism scheme will allow inclusion of a wider spectrum of isolates while retaining its explanatory power. This scheme was also found to be partially congruent with NTS typing technique.

The current Indian epidemic of superficial dermatophytosis due toTrichophyton mentagrophytes—A molecular study

“…Today, however, by molecular methods, as many as eight genotypes are distinguished within the zoophilic species T mentagrophytes . These are, namely, T mentagrophytes ITS Type III (Europe) and III* (Cosmopolite) all the way up to Type IX (Australia) (Table ) . All strains from our Indian study belong only to the genotype ITS Type VIII (Asia: India, Iran and Oman).…”

“…55 Table 4). 22 All strains from our Indian study belong only to the genotype ITS Type VIII (Asia: India, Iran and Oman). We further wish to reiterate that the Indian genotype of T mentagrophytes isolated in this study is a true zoophilic species and is different from the anthropophilic species T interdigitale ITS Type I and Type II.…”

“…All 138 strains are included in the phylogenetic tree in Figure 3A (ITS) and Figure 4A (TEF 1α gene Figure 3B, Table 4). 22,23 An overview of the currently known genotypes has recently been published by the authors of this study. 10 Initial experiments to investigate the type of mating genes of the…”

A severe transmissible Majocchi's granuloma in an immunocompetent returned traveler

“…The ITS regions 1 and 2 were identified from the de novo assembly and aligned to ITS sequences representing all known Trichophyton interdigitale types [3], [4]. The ITS regions were determined to be 100% identical to the type IV-variant found in RCPF-1640, a strain causing tinea corporis.…”

“…The ITS regions were determined to be 100% identical to the type IV-variant found in RCPF-1640, a strain causing tinea corporis. In the literature type IV strains have been reported to be associated with zoophilic sources [4].…”