Trichophyton mentagrophytes ITS Genotype VII from Thailand

Currently, in Germany, Switzerland, and Austria, a new and until now not known entity of inflammatory and abscessing dermatophyte infection is observed. In particular, these deep infections of the skin and their appendages include Tinea pubogenitalis, Tinea cruris, Tinea barbae, Tinea corporis, and Tinea capitis. Some of the patients came back from a journey to Thailand or South East Asia where transmission occurred. But, independently from a journey to abroad, the dermatophyte might be transferred in Germany, too. In every case, this deep infection is caused by the zoophilic dermatophyte Trichophyton mentagrophytes of the newly described Internal Transcribed Spacer (ITS) genotype VII. From 24 patients with dermatomycoses, altogether 25 isolates of T. mentagrophytes were isolated in the last 6 years. Among them were both male and female patients, the age range was from 1 to 50 years. The infection was affecting the pubogenital area, the capillitium, the face, or the trunk. Most of these infections were acquired in Germany without a stay abroad. A total of 25 dermatophyte isolates—all belonging to T. mentagrophytes—could be characterised. Species identification was confirmed for all isolates by sequencing of the ITS region of rDNA genes. Molecular relationship of the 24 isolates in comparison to already known genotypes within this species was depicted in a phylogenetic tree. The sequences obtained for these isolates are forming their own phylogenetic cluster, corresponding to a new genotype, the ITS genotype VII (“Thai variant”). This genotype is clearly set up from other clusters of T. mentagrophytes, e. g. zoophilic strains isolated from animals and human dermatophytoses, and from T. mentagrophytes genotype VIII “India”. This genotype, as the other zoophilic T. mentagrophytes genotypes, can also be distinguished from the anthropophilic Trichophyton interdigitale.