Tinea capitis caused by Trichophyton equinum

[Trichophyton equinum meets Chanel]

The horse is the most common reservoir of Trichophyton (T.) equinum. However, this zoophilic dermatophyte only rarely causes infections in humans. The following case report describes such a case. In addition to epidemiology, treatment is described and the morphological and physiological characteristics of T. equinum are illustrated. Because of its formation of spiral hyphae and nodal organs, which has not been previously documented for this species, the isolated strain was deposited in the German Collection of Microorganisms and Cell Cultures (DSM No. 114196).

Tinea corporis caused by Trichophyton equinum transmitted from asymptomatic dogs to two siblings

Each year, millions of people worldwide are affected by superficial mycoses, which are frequently caused by dermatophytes having affinity to the scalp, nails, hair and the stratum corneum of the skin. The changing reservoirs of zoophilic dermatophytes, the numerous reports of animal carrier status, and the increasing number of pets make the diagnosis difficult, which is usually impossible based only on medical history. Herein we present a case report of tinea corporis caused by Trichophyton equinum in siblings who had no contact with horses. The routine laboratory diagnostic procedures for identification of isolates were based on phenotypic and genotypic characteristics, especially molecular techniques using rDNA internal transcribed spacer sequences. The results showed that both techniques proved to be insufficiently discriminatory to differentiate two closely related species, i.e. Trichophyton equinum and Trichophyton tonsurans. Introduction of a TEF1 sequence analysis to the diagnostic procedures revealed consistent differences between these two species and facilitated unambiguous identification. Interestingly, dogs that could leave the homestead freely were the source of the infection in children. In conclusion, Trichophyton equinum was considered in the past as a strict zoophilic dermatophyte associated with horses and rarely transmitted to humans. This study revealed that this species can have other reservoirs and live in the fur of asymptomatic animals.

Tinea corporis caused by Trichophyton equinum in a rider and review of the literature

BACKGROUND

Trichophyton equinum is a zoophilic dermatophyte usually causing ringworm in horses. Cases of skin infections in humans are very rare. CASE REPORT : ​We describe a case of tinea corporis caused by T. equinum on a buttock of a rider who often rode bareback with short trousers.

CONCLUSION

Although T. equinum was considered in the past as a strict zoophilic dermatophyte, our case report confirms that it can cause dermatophytoses also in humans. A review of epidemiological and clinical features of human infections caused by T. equinum is presented.

Nucleotide sequence analysis of beta tubulin gene in a wide range of dermatophytes

We investigated the resolving power of the beta tubulin protein-coding gene (BT2) for systematic study of dermatophyte fungi. Initially, 144 standard and clinical strains belonging to 26 species in the genera Trichophyton, Microsporum, and Epidermophyton were identified by internal transcribe spacer (ITS) sequencing. Subsequently, BT2 was partially amplified in all strains, and sequence analysis performed after construction of a BT2 database that showed length ranged from approximately 723 (T. ajelloi) to 808 nucleotides (M. persicolor) in different species. Intraspecific sequence variation was found in some species, but T. tonsurans, T. equinum, T. concentricum, T. verrucosum, T. rubrum, T. violaceum, T. eriotrephon, E. floccosum, M. canis, M. ferrugineum, and M. audouinii were invariant. The sequences were found to be relatively conserved among different strains of the same species. The species with the closest resemblance were Arthroderma benhamiae and T. concentricum and T. tonsurans and T. equinum with 100% and 99.8% identity, respectively; the most distant species were M. persicolor and M. amazonicum. The dendrogram obtained from BT2 topology was almost compatible with the species concept based on ITS sequencing, and similar clades and species were distinguished in the BT2 tree. Here, beta tubulin was characterized in a wide range of dermatophytes in order to assess intra- and interspecies variation and resolution and was found to be a taxonomically valuable gene.