Two Trichophyton mentagrophytes isolates from skin lesions on a girl and her rabbit, which were identified as Arthroderma benhamiae by mating tests, were studied by mtDNA (mitochondrial DNA) analysis and sequencing of ITS (internal transcribed spacer) regions of nuclear ribosomal RNA genes.
The mtDNA-RFLP (restriction fragment length polymorphism) patterns showed the two isolates to be T. verrucosum rather than A. benhamiae. The ITS sequence showed the isolates to be closer to A. benhamiae Americana-European race than to T. verrucosum and closer to T, verrucosum than to their mating partner A. benhamiae African race.
These results suggest that there are three genetic types of A. benhamiae - an Americano-European type, an African type and a T. verrucosum type - and that T, verrucosum is an anamorph of A. benhamiae.