Morphology and molecular biological identification of Trichophyton mentagrophytes

Objective To reclassify 36 strains of Trichophyton mentagrophytes from patients and 5 strains from foxes by the new classification system,and to evaluate if the traditional methods satisfy the clinical identification.Methods Trichophyton mentagrophytes were cultured on SDA,1% peptone agar and BCP-MSG.The morphology was observed and urease test and hair perforation test were performed.Then the new identification was reclassified by ITS and LSU sequence analysis.Results ①Morphology and physiology of 41 tested strains met the characteristics of Trichophyton mentagrophytes(38 strains) and Trichophyton rubrum(3 strains).②ITS sequence analysis identified the species of Trichophyton mentagrophytes and Trichophyton rubrum but LSU sequence analysis only identified the telemorph of Trichophyton mentagrophytes(36/38).Conclusions Traditional identification methods are still effective and reliable.Trichophyton mentagrophytes from patients are identified as Trichophyton interdigitale(38/38),but strains from foxes belong to Arthroderma benhamiae,not to Arthroderma vanbreuseghemii by LSU sequence analysis,which is more useful than ITS sequence analysis.