抗真菌剤の標的候補としての必須遺伝子群を，一倍体として増殖する Candida glabrata の温度感受性変異株（ts 変異株）を用いて効率的に探索・同定する方法（ETS システム）を確立した．本システムは，「ts 変異はゲノム上の必須遺伝子内に起こった点突然変異により生ずる」との一般的概念を基礎とし，C. glabrata Genomic DNA Library（GDL）からこの ts 変異を相補する必須遺伝子を分離・同定するものである．ETS システムを用いることにより，ts 変異株の一つ，T-3 株より，出芽酵母 TEM1 遺伝子の相同遺伝子 CgTEM1 を必須遺伝子として分離・同定できることが示された．ts 変異株 T-3 の CgTEM1 領域内に見出された点突然変異（Asp-143/Asn）は，この CgTEM1 遺伝子により相補されることが確認された．本研究により，病原性酵母 C. glabrata 由来の必須遺伝子群を ts 変異に対する相補活性を保有する遺伝子として分離できることが示された．ここで確立した ETS システムは，将来の抗真菌剤開発における有用な標的候補を提供するものと考えられる．

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  Background : Dermatophytes are common in both developed and developing countries, the species involved and the resulting clinical entities vary geographically. Aim of study: To determine public health importance of dermatophytes with special regard to the distribution of the zoophilic species among the examined human cases. Methods: Patient specimens (dermatophytosis-like lesions) were mycologically examined using direct microscopic and cultural examinations. Results: The overall dermatophyte infection rates among the examined patients (260) were 81.5% and 61.9% by direct microscopic and cultural examinations, respectively. A total of 161 dermatophyte isolates were obtained from culturally positive human specimens. The most common isolated species were Trichophyton violaceum (60, 37.3%) and Microsporum canis (46, 28.6%), followed by Trichophyton rubrum (20, 12.4%), Trichophyton tonsurans (16, 9.9%) and Trichophyton mentagrophytes (11, 6.8%). The less frequently isolated species were Trichophyton verrucosum (3, 1.9%), Epidermophyton floccosum (3, 1.9%), Microsporum gypseum (1, 0.6%) and Microsporum audouinii (1, 0.6%). The current study further revealed that out of 161 culturally positive patients, 61 (37.9%) had contact with pet animals, 6 (3.7%) had contact with farm animals, 7 (4.3%) had a history of rodent presence in or around their home and 87 (54%) had no contact with animals. Conclusions and recommendations: Although the anthropophilic species dominated the aetiology of human dermatophytosis in present study, the zoophilic species represented nearly one third of the totally obtained isolates, with the most important organisms being M. canis, T.mentagrophytes var. mentagrophytes and T. verrucosum. These findings indicate the necessity of human beings taking appropriate control measures when they are in contact with animals.

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We previously developed an N-acetyl-D-glucosamine (GlcNAc) medium which induces Candida albicans to undergo a yeast-to-hyphal transition through a cAMP-PKA pathway. Microarray analysis demonstrated that 18 genes, including ALS3 that encodes a cell wall adhesion, were upregulated by 30-min incubation of yeast cells at 37°C in the GlcNAc medium. To investigate the differences between morphological transition and morphotype in C. albicans as a consequence of infection, this study utilized a silkworm infection model as an invertebrate mini-host. We prepared 3 different conditions of C. albicans cells in vitro by changing the incubation times in the GlcNAc medium: yeast-form cells at 0 min (Y0 cells), yeast-form cells in germination-ready state at 60 min (Y60 cells), and hyphal cells at 120 min (H120 cells), and compared their pathogenicities. We performed the infection study at various temperatures to find temperature-dependent virulence factors in vivo. Y60 cells in germination-ready state in the GlcNAc medium showed higher pathogenicity in vivo compared to Y0 and H120 cells at 30°C. Y60 cells proliferated in silkworms 24 h post-injection at 30°C, whereas the other 2 cell types did not. In vitro analysis demonstrated that Y60 cells, but not Y0 cells, germinated in the silkworm hemolymph at 30°C. However, Y0 and Y60 cells showed a similar degree of germination in the silkworm hemolymph at 37°C, although no significant difference in silkworm survival after infection with each cell type was observed at 37°C. These results suggested that the germination-ready state induced by the GlcNAc medium contributed to virulence in the silkworm.

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  皮膚科領域の真菌症から原因菌を分離培養することは皮膚科医にとって比較的容易であるが，培養された菌の正確な同定にはスライド培養が必要とされることが多い．今回従来のスライド培養法の煩雑な部分を改良した簡便なスライド培養法を考案したので報告した．これはカバーガラスよりわずかに大きな，密閉できる蓋付きポリプロピレン製小物収納用ケース内でカバーグラス上に菌を発育させるもので，このケース以外特別な用具を必要とせず，一度に複数の標本を作ることが可能な方法である．得られた標本も質的に従来のスライド培養法と変わらなかった．本法は皮膚科診察室でも容易に真菌の同定を行える有用な手法と考えられる．

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