Molecular determination of dermatophyte fungi using the arbitrarily primed polymerase chain reaction

Abstract

Dermatophytes are keratinophilic fungi capable of causing dermatophytosis (commonly known as tinea or ringworm) in humans and animals. Previously, we reported the differentiation of the common dermatophytes Trichophyton rubrum, T. mentagrophytes and T. tonsurans using a random primer 5'-ACCCGACCTG-3' (OPAA11) in the arbitrarily primed polymerase chain reaction (AP-PCR). In the present study, by examining additional dermatophytes including eight Microsporum spp., 16 Trichophyton species/subspecies and Epidermophyton floccosum using both OPAA11 and a second random decamer 5'-GAGAGCCAAC-3' (OPD18) in AP-PCR, we show that except for T. rubrum and T. gourvilli, and three T. mentagrophytes varieties, most of the dermatophyte fungi investigated formed distinct DNA band patterns on gel electrophoresis. The amplification of specific DNA bands in AP-PCR appeared to be independent of culture variations shown by dermatophyte isolates. These results provide the basis for the rapid identification of dermatophytes at the genetic level, supplementing existing laboratory methods and improving the diagnosis of human dermatophytosis.

Dermatophytosis, Trends in Epidemiology and Diagnostic Approach

“…A Japanese group used this method with a random primer (OPAA11) in the arbitrarily primed polymerase chain reaction (AP-PCR). Except for T. rubrum and T. gourvilli, and three T. mentagrophytes varieties, most of the dermatophyte fungi investigated formed distinct DNA band patterns on gel electrophoresis (Table 3) [109]. Other investigations by this group have highlighted the interest in AP-PCR for dermatophyte identification [110][111][112][113].…”

Molecular typing of Trichophyton rubrum clinical isolates from Poland

“…Indeed, several reports revealed little or no interstrain DNA polymorphism using a range of molecular typing procedures. [5][6][7][8][9] Conversely, substantial genetic variation within T. rubrum has recently been reported with the amplification of two tandemly repetitive subelements, TRS-1 and TRS-2, located in the rDNA nontranscribed spacer (NTS) region. 10 More recently, randomly amplified polymorphic DNA (RAPD) analysis with two primers, designated 1 and 6 has been successfully applied to the differentiation of T. rubrum strains.…”

PCR and PCR–RFLP techniques targeting the DNA topoisomerase II gene for rapid clinical diagnosis of the etiologic agent of dermatophytosis

“…However, morphological identification is time-consuming and requires some experience, because it is difficult to identify fungal species showing poor characteristics in their morphological features. Recently, molecular biology-based techniques, such as polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), random amplification of polymorphic DNA (RAPD), PCR fingerprinting, and Southern blotting, have been adapted to the identification of dermatophytes [9][10][11][12][13], which may be simpler and more efficient than the conventional tests. In particular, because of its speed, reproducibility, high sensitivity, and specificity, diagnostic PCR has been used in laboratories for the identification of fungal species [14].…”