Molecular epidemiology of Arthroderma benhamiae, an emerging pathogen of dermatophytoses in Japan, by polymorphisms of the non-transcribed spacer region of the ribosomal DNA
Introduction
Dermatophytes are a specialized group of fungi which infect keratinized tissues of humans and animals. Among these dermatophytes, Trichophyton mentagrophytes is found in many countries, and is considered to be one of the most important causative agents for both human and animal dermatophytoses. However, mating studies have revealed that T. mentagrophytes is biologically a species-complex composed of three teleomorphic species, Arthroderma benhamiae, A. vanbreuseghemii and A. simii, and several anamorphic varieties [1]. In early 1980, A. benhamiae isolates could not be found in Japan from a mating study [2], [3]. Recently, however, several isolates of A. benhamiae have been established from human and animal specimens in Japan. All the isolates were from pet rabbits and a pet guinea pig and from the animal owners’ family of the pet animal and from a pet shop worker [4], [5], [6]. Therefore, A. benhamiae was probably introduced into Japan through animals imported from abroad [4], [5].
Recent advances in molecular biology indicated that a very sensitive technique, the analysis of length variation of non-transcribed spacer (NTS) regions of the ribosomal (r)DNA, might be useful in sub-typing the isolates of T. rubrum [7]. In the present study, we attempted to evaluate the molecular typing of A. benhamiae isolated in Japan to try to determine the origin and source of the isolates.
Section snippets
A. benhamiae strains
By October 2000, in Japan, eight clinical isolates of A. benhamiae had been established (Table 1). All eight isolates were used in this study. All of the isolates have been identified by standard morphological and mating studies. Among them, VUT 00002 and VUT 00003 were isolated from different animals. KMU 4136 and 4137, KMU 4169 and 4170 had the same origins respectively. Four tester strains for the mating study, all of which were provided by Prince Leopold Institute for Tropical Medicine,
Preliminary screening using RFLP analysis of the ITS regions
The RFLP profiles of the eight isolates of A. benhamiae were observed and were compared with each other and with those of typical clinical isolates of T. mentagrophytes var. interdigitale, SM 8796, tester strains of A. benhamiae, A. simii and A. vanbreuseghemii (Fig. 2). All eight isolates and the A. benhamiae strains had the same RFLP profile, whereas T. mentagrophytes var. interdigitale, A. vanbreuseghemii and A. simii had profiles characteristic of each of the taxa.
DNA typing based on polymorphisms of the NTS regions
Three bands about 2.5, 3.2
Discussion
Among the three teleomorphic species of the T. mentagrophytes complex, the incidence of isolation of A. benhamiae as a causative agent for human and animal dermatophytoses varies very much from one report to another. The highest incidence among freshly isolated T. mentagrophytes from clinical specimens was recorded in Czechoslovakia with a rate of 26.4% (27 of 102 isolates) [11] compared with 22.5% (30 of 133 isolates) in culture collected in Belgium [1] and only 1.5% in France (three of 200
Acknowledgements
We are very grateful to Professor E.G.V. Evans, Dr C. Jackson and Dr R. Barton, University of Leeds, UK, for their useful advice and encouragement.
References (16)
The Trichophyton mentagrophytes complex
- et al.
Mating behavior of 334 Japanese isolates of Trichophyton mentagrophytes in relation to their ecological status
Mycologia
(1980) - et al.
Difference or similarities of the clinical lesions produced by ‘+’ and ‘−’ types members of the ‘mentagrophytes’ complex in Japan
- et al.
The first isolation of Arthroderma benhamiae in Japan
Microbiol. Immunol.
(1998) - et al.
Two cases of tinea corporis by infection from a rabbit with Arthroderma benhamiae
Jpn. J. Med. Mycol.
(2000) - Tosaki H, Fujihiro M, Mochizuki T. A case of tinea manus and faciei with Arthroderma benhamiae. Nishinihon J Dermatol,...
- et al.
Species identification and strain differentiation of dermatophyte fungi by analysis of ribosomal-DNA intergenic spacer regions
J. Clin. Microbiol.
(1999) - et al.
Phylogenetic classification of Trichophyton mentagrophytes complex strains based on DNA sequences of nuclear ribosomal internal transcribed spacer 1 regions
J. Clin. Microbiol.
(1998)
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