Trichosporon asahii is the major causative agent of the opportunistic infection trichosporonosis, and also causes summer-type hypersensitivity pneumonitis (SHP). Random amplification of polymorphic DNA analysis was used to determine the intraspecies diversity of T. asahii isolates from clinical specimens, the houses of SHP patients, and environmental material. Clinical isolates formed a cluster, characterized by a 90% matching coefficient, but they did not cluster with strains isolated from SHP patients' houses or environmental sources. The biochemical characteristics of T. asahii isolates from the three sources were compared, and a phenogram was constructed. One of the two clusters included most of the clinical isolates and strains isolated from the houses, and the other cluster included most of the environmental isolates. There was a remarkable difference in the abilities of the strains belonging to these clusters to utilize several compounds. These results suggest that the genetic diversity and biochemical characteristics of T. asahii are related to the source of the isolates.
In addition, based on the IGS1 sequence, which is located between the 26S and 5S rRNA genes, we identified five genotypes of T. asahii, which is a major causative agent of deep-seated trichosporonosis. Of the five genotypes, three were isolates that originated in Japan, whereas two were American isolates. IGS sequence analysis shows great potential as a new epidemiological tool.

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We report a case of Trichophyton mentagrophytes infection. A 27-year-old female dairy worker visited our hospital in August 2001 for evaluation of an erythematous lesion near her right eye. The patient had been treated with antibiotics and an anti-allergic drug at another clinic with no effect on the lesion. KOH preparation of the scale revealed mycelia and T. mentagrophytes was isolated from the culture. The isolated pathogen was identified as T. mentagrophytes animal type 1 by the classification system based on the cluster analysis of nuclear ribosomal internal transcribed spacer 1 (ITS1) DNA sequences. The oral administration of terbinafine at 125mg/day and antifungal cream was effective. T. mentagrophytes is one of the most common dermatophytes isolated from humans and animals. We should be aware that animals may carry this kind of fungal pathogen.

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Animal bones after being devitalized at death are strongly resistant to wear and tear and remain in the soil or environment much longer than other organic components from dead animals. Yet over the course of time they seem to disappear and thus our ecological surroundings are not cluttered with bone remnants. Mechanical factors creating compression or friction and chemical factors like pH of the soil and surroundings must together have provided concerted degrading effects. Microorganisms in the soil also help in this process by utilizing the organic components of devitalized bones. Certain highly pathogenic fungi that have been collected from soil from time to time and many other environmental fungi may take part in the degrading of the bone remnants. In this study, several strains from the highly pathogenic dimorphic fungi Coccidioides immitis, Blastomyces dermatitidis, Histoplasma spp., Paracoccidioides brasiliensis and also some strains of dematiaceous fungi (Exophiala spp. and Foncecaea pedrosoi) were inoculated to dissected and devitalized murine long bones that had been placed on solidified water agar plates to see if they would survive, grow and invade the bones. After being kept for 12 weeks at 25°C all the parts of the histological sections of these bones showed invasion by most of the strains used in this study, although the cortical component of the bony architecture seemed to be comparatively resistant to invasion. Their ability to grow and sporulate in the aforementioned nutrient-limiting condition hinted at a possible role of these fungi in the degradation of devitalized bones.

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A 10-year-old Peruvian girl, living in Japan since 1996, visited our hospital in August 2000 complaining of alopecia which had been present on her scalp for one year. The bald areas appeared as multiple small, scattered, angular patches with indistinct margins. Follicular pustules, erythemic nodules and lymphadenopathy were also seen.
In the culture of the affected hair, a tan surface with wiry undulations grew on Sabouraud's media. The colony reverse had reddish-brown central pigmentation. Slide cultured fungi produced great numbers of round and short club-shaped microconidia, hyphae and intercalary chlamydospores. These fungi showed the following characteristics: positive urease test, no pigment production on cornmeal agar and positive thiamine dependency.
The restriction fragment length polymorphism pattern and the nucleotide sequences of ribosomal-DNA internal transcribed spacer region of the causative fungus was compatible with Trichophyton tonsurans.
Daily administration of 125mg of terbinafine resulted in a satisfactory response and the lesion healed almost completely.

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An epidemiological survey of Trichophyton mentagrophytes var. erinacei in the household hedgehog and other rodents was made between January 17, 2002 and February 28, 2002 in Japan. Quills and hairs were collected from sources identified via the internet. The fungus was isolated only from the quills of four-toed hedgehogs (7/18; 39%) from Kanto to Kyushu regions. Isolates were examined morphologically, physiologically and genetically, and identified as T. mentagrophytes var. erinacei anamorph. The isolates were also genetically compared with European hedgehog (Erinaceus europeus)-borne T. mentagrophytes var. erinacei and Kenyan hedgehog (Aterelix albiventris)-borne Arthroderma benhamiae, and their genotypes of the ITS1-5.8S-ITS2 rDNA were all identical. The isolates were crossed with A. benhamiae Americano-European race and African race, A. vanbreuseghemii and A. simii, with the result that they mated only with African race (+) or (-). Mating types of the isolates were (+) in 6 isolates and (-) in one. An intra-isolate mating between one of the 6 plus isolates and the minus one formed abundant mature gymnothesia, the mating type ratio of the F1 progeny was approximately 1:1, and the sib crossings of F1 progeny produced abundant fertile gymnothesia. The present study revealed that the intra-Japanese hedgehog-borne isolate crossing showed complete fertility and that the sexual degeneration pointed out by Takashio (Mycologia 71: 968-976, 1979) did not exist. Two pairs of mating, (+) and (-) mating types of Japanese isolates with (-) and (+) tester strains of A. benhamiae African race formed less gymnothesia, mating type ratios were unbalanced, and sib crossings of F1 progeny produced small gymnothesia containing a low number of asci, pseudogymothesia, or none, respectively. These results show that A. benhamiae var. erinacei, the teleomorph of T. mentagrophytes var. erinacei, belongs to a different mating group (e. g. hedgehog race) than the Americano-European and African races in A. benhamiae.

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