However, the designed TR primers also detected the closely related T. violaceum species (from reference strain and culture). When primer pairs for TM were used, a cross-amplification occurred with T. schoenleinii, T. verrucosum and T. tonsurans

DNA known to include highly similar ITS sequences and related taxonomic features (Fig. 2). For Epidermophyton floccosum, Microsporum canis, M. gypseum, M. ferrugineum the MX PCR yielded amplification with only Derm primers (Fig. 2). ALK inhibitor Extracted DNA from 58 clinical dermatophyte isolates including 23 TR and 35 TM strains was used for the evaluation of Derm, TR and TM primers separately and then in a MX PCR assay (Fig. 3). When tested separately in the TR specific PCR, all T. rubrum DNA samples (100%) yielded the expected 214 bp product. No PCR product was detected when the 23 T. rubrum samples were tested in the TM specific PCR. When tested separately in the TM specific PCR, all T. mentagrophytes strains (100%) showed the specific 132 bp product. No PCR product was detected when the 35 T. mentagrophytes samples were tested in the TR specific PCR. Hence, all of the 23 T. rubrum and 35 T. mentagrophytes samples were positive in both Derm PCR and MX PCR. The results of the mycological examination of the 201 toenail samples are shown in Table 3. Direct

examination was positive in 151 (71.1%) and culture in 132 (65.6%) of them respectively. Out c-Met inhibitor of the 151 samples found positive on direct examination, 112 were identified by culture as T. rubrum, four as T. mentagrophytes and four as T. violaceum. For the 31 remaining samples, culture was either negative or contaminated. For the 132 culture positive selleck specimens, the causal agent was T. rubrum in 122 cases, T. mentagrophytes in six cases

and T. violaceum in four cases. Culture was negative or contaminated for 69 specimens including the 31 samples found positive on direct examination. All specimens taken from non-infected (healthy) nails were negative on both direct examination and culture. No mixed dermatophyte infections were detected in culture. The MX PCR was positive in 195 (97%) specimens out of the 201 investigated nail samples. It identified T. rubrum in 109 (54.2%) samples, T. mentagrophytes in 12 (5.9%) samples and another dermatophyte species in 8 (3.9%) samples (Fig. 4). Sixty-six samples yielded three bands (32.8%) and six specimens were negative. Furthermore, 63 of 69 (91.3%) of culture negative or contaminated specimens gave positive MX PCR results. Thirty-one of them were positive on direct examination. Out of the 63 specimens, 8 yielded positive PCR results with only Derm primers; 20 were positive with both Derm and TR primers; 10 were positive with both Derm and TM primers. The 25 remaining samples yielded three bands in MX PCR (Table 3). In 66 (32.