Strain differentiation of Trichophyton rubrum by random amplification of polymorphic DNA (RAPD)

Abstract

SUMMARYTrichophyton rubrum is an important cause of dermatomycoses. Molecular strain typing methods have recently been developed to address questions about epidemiology and source of relapse following treatment. This report describes the application of RAPD for molecular strain differentiation of this fungus utilizing the primers 1-(5'-d[GGTGCGGGAA]-3') and 6-(5'-d[CCCGTCAGCA]-3'). A total of five RAPD patterns were observed among 10 strains of T. rubrum, with each of the primers used. We conclude that RAPD analysis using primers 1 and 6 can be used in epidemiological studies.

Identification and differentiation of Trichophyton rubrum clinical isolates using PCR-RFLP and RAPD methods

“…However, Jackson et al have recently reported on intraspecific variability within T. rubrum by PCR-amplifying two tandemly repetitive subelements (TRSs), located in the non-transcribed spacer (NTS) region of the rRNA gene cluster [15]. More recently, the RAPD analysis performed by Baeza et al with two decameric primers, designated 1 and 6, has been shown to produce a high degree of interstrain polymorphism [7, 16]. The RAPD analysis with primers 1 and 6 was also applied in the present study, and this choice was motivated by a high discriminatory potential of the method, higher than that of the TRS typing system [16].…”

“…It yielded 40 profiles, whereas RAPD with primer 6 resulted in only five profiles (GDRs of 72.7% and 9.1%, respectively). In the first study that used primers 1 and 6, among ten clinical isolates of T. rubrum , five molecular patterns were observed for each primer [7]. In a subsequent study including 67 T. rubrum isolates, a total of 12 and 11 individual patterns were obtained by RAPD with primers 1 and 6, respectively (GDRs of 17.9% and 16.4%, respectively) [16].…”

“…Two primers, designated 1 and 6, as devised by Baeza and Mendes-Giannini [7], were used in two separate randomly amplified polymorphic DNA (RAPD) assays. Amplification products were resolved by electrophoresis using 1.5% agarose gels and were photographed under UV light after Et-Br staining.…”

Molecular typing and antifungal susceptibility of Trichophyton rubrum isolates from patients with onychomycosis pre- and post-treatment

“…Epidemiological studies of dermatophytic infections have now entered a new era, due to the ability to differentiate strains of fungi by molecular typing [2,5,6,16,17]. By using molecular methods, the existence of multiple strains of T. rubrum in only one affected nail was shown and it was also found that a nail fragment containing fungal elements from more than one strain can develop into a single colony [2].…”

“…In cases of recurrent post-treatment onychomycosis, information obtained by strain fingerprinting would determine whether the original isolate has been responsible, or a new strain has been acquired or even if multiple strains are involved in the condition [5,6]. The discrimination achieved by random amplified polymorphic DNA analysis and restriction analysis of the mitochondrial DNA is generally adequate for species identification, but is insufficiently sensitive for strain differentiation of T. rubrum isolates [3,7].…”