Microsatellite-primed PCR and random primer amplification polymorphic DNA for the identification and epidemiology of dermatophytes

This study demonstrates the capacity of the one-step polymerase chain reaction (PCR) fingerprinting method using the microsatellite primers (GACA)₄ or (GTG)₅ (MSP-PCR) to identify six of the most frequent dermatophyte species causing cutaneous mycosis. PCR with (GACA)₄ was a suitable method to recognise Microsporum canis, Microsporum gypseum, Trichophyton rubrum and Trichophyton interdigitale among 82 Argentinian clinical isolates, producing the most simple and reproducible band profiles. In contrast, the identification of Trichophyton mentagrophytes and Trichophyton tonsurans was achieved using PCR with (GTG)₅. In this way, the sequential application of PCR using (GACA)₄ and (GTG)₅ allowed the successful typification of clinical isolates which had not been determined by mycological standard techniques. In this work, the intraspecies variability among 33 clinical isolates of M. canis was detected using random amplification of polymorphic DNA (RAPD-PCR) with the primers OPI-07 and OPK-20. The genetic variations in the isolates of M. canis were not associated with clinical features of lesions or pet ownership, but a geographical restriction of one genotype was determined with OPK-20, suggesting a clonal diversity related to different ecological niches in certain geographical areas. The results of this work demonstrate that the detection of intraspecies polymorphisms in M. canis by RAPD-PCR may be applied in future molecular epidemiological studies to identify endemic strains, the route of infection in an outbreak or the coexistence of different strains in a single infection.