One year overview of non-T. rubrum dermatophytes isolated in Czech Republic and identified by molecular methods
Abstract
A large aggregate of clinical isolates of non-T. rubrum dermatophytes involving almost 300 isolates was collected during a first year of study. The isolates were obtained from clinical specimens provided by the six regional institutions across Czech Republic.
To determine the species, isolates were subjected to comparative sequence analysis by use of the internal transcribed spacer and PCR-fingerprinting method with primer M13-core. Trichophyton interdigitale was the most abundantly recovered (36%) species followed by Trichophyton sp. anamorph of A. benhamiae (25%) and Microsporum canis (22%).
All other species comprised 17% of isolates. Approximately 6% of isolates identified as T. interdigitale by morphology was re-determined as M. persicolor using molecular approach.
Microsporum fulvum masquerading as M. gypseum was another discovered cryptic species which comprised one fourth of isolates originally identified as M. gypseum by morphology. Complete list of determined species involved in addition T. tonsurans, Epidermophyton floccosum, T. terrestre and T. verrucosum.
The identification based on morphology alone may be difficult due to extreme phenoplasticity and convergent features exhibited by dermatophytes. Extensive changes have been done recently in concept of numerous taxa using molecular data and mating experiments.
Nevertheless, appropriate reclassification supported by phenetic data was not published. In conclusion, molecular methods are increasingly being used to assist in identification of dermatophyte species according to new species concept and allow us to determine cryptic species that are easily miss-identified by morphological methods.