Survey of Dermatophyte Infections in the Lausanne Area (Switzerland)

Abstract

Background: The dermatophytes are important in the Swiss medical environment since 5–10% of consultations in dermatology concern mycotic infections. Objective: To obtain information about the prevailing species of dermatophytes in the south-west of Switzerland and their pattern of infection. Methods: An analysis was made of the dermatophytes isolated in the Department of Dermatology at the University Hospital of Lausanne and from samples collected in private practices of Switzerland during an 8-year period (1993–2000). The total number of samples sent for mycological analysis was 33,725. Results: 4,193 cultures revealed a dermatophyte. Trichophyton rubrum was the most frequently isolated species accounting for 62.5% of the strains followed by T. mentagrophytes (24.5%) and Microsporum canis (5.0%). Less frequent isolates included Epidermophyton floccosum, M. langeroni, M. gypseum, T. soudanense, T. violaceum, T. verrucosum, T. gourvili and T. tonsurans. Analysis of the localisation of the isolated fungi confirms that the dermatophyte species have a predilection for certain body areas. Conclusions: The relative frequencies of isolation of the dermatophyte species partially depending of the record of the different tinea vary from one country to another. Our study reveals the importance of T. rubrum and the appreciable frequency of M. canis in the Swiss autochthonous population and the apparition of new species with immigrants.

Phylogenetic analysis of Trichophyton mentagrophytes human and animal isolates based on MnSOD and ITS sequence comparison

“…Members of the Trichophyton mentagrophytes species complex are common agents of human dermatophytosis in Europe (Kardjeva et al, 2006;Monod et al, 2002), invading skin layers (Kaufman et al, 2004) and causing superficial infections, such as tinea pedis or athlete's foot (De Hoog et al, 1998;Weitzman & Summerbell, 1995), with an increased incidence since 1965 (Kardjeva et al, 2006). The species included in this anthropo-zoophilic complex, which were first defined on the basis of morphological features and mating-type studies, have more recently been investigated using molecular methods, revealing an organization more complex than expected.…”

Multiplication of an ancestral gene encoding secreted fungalysin preceded species differentiation in the dermatophytes Trichophyton and Microsporum

“…Among approximately 10 human pathogenic species isolated in Europe, Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis are most commonly observed, accounting for 72-95 % of the species isolated in hospital and private practices (Monod et al, 2002a). A characteristic of the dermatophytes is their ability to grow exclusively in the stratum corneum, nails or hair and to digest components of the cornified cell envelope.…”

Identification of Dermatophyte Species by 28S Ribosomal DNA Sequencing with a Commercial Kit

“…These fungi have the capacity to invade keratinized tissue of humans or animals to produce infections that are generally restricted to the corneocytes of the skin, hair, and nails. Among the approximately 10 species isolated in Europe, Trichophyton rubrum and T. mentagrophytes are the most commonly observed, with frequencies varying from 27 to 74% and from 17 to 41%, respectively (13).…”

“…For instance, T. rubrum is especially dominant in onychomycoses whereas M. canis is especially prevalent in tinea capitis and tinea corporis (13). In contrast, some species of dermatophytes are never or rarely isolated from a particular dermatophytosis.…”