Dermatophytes are fungi that infect the human skin and its appendages. With new pathogenic species emerging and resistance to first-line drugs rising, microbiologic diagnosis and species identification are becoming even more important. In this study, the DermaGenius® 2.0/3.0 Complete multiplex real-time PCR and the EUROArray Dermatomycosis kits were compared to fungal culture and with each other; 78 reference strains and 124 clinical samples were analyzed. Both the DermaGenius® kit (97%; 95%CI 89-100%) and the EUROArray assay (91%; 95% CI: 82-96%) were sensitive when analyzing on-panel reference strains. In clinical samples, the DermaGenius® assay provided a positive result in 63 out of 124 (51%) samples and the EUROArray assay in 74 out of 124 (60%) samples. Both kits supported the diagnosis and species identification of culture-negative samples, and samples with growth of unconventional species. However, there was suspicion of false-positive results with F. solani in the EUROArray kit both in clinical and reference strains. The most common conventional dermatophytes in this study combining all methods were T. rubrum/soudanense (n = 40) and T. interdigitale/mentagrophytes (n = 11). In summary, both PCR kits were sensitive for the diagnosis and species identification of dermatophytoses. Combining culture and a PCR-based method can increase the diagnostic yield and compensate for the weakness of the other methods. The optimal PCR-based kit, and especially the optimal panel size, depends on the local epidemiology of dermatophytes.
Keywords: dermatophytes; diagnostics; fungal culture; multiplex PCR.