研究者業績

矢口 貴志

ヤグチ タカシ  (Takashi Yaguchi)

基本情報

所属
千葉大学 真菌医学研究センター 准教授
学位
博士(工学)(早稲田大学)

J-GLOBAL ID
200901010374246864
researchmap会員ID
5000067659

論文

 264
  • Syuhei Arai, Daigo Wakana, Takeshi Itabashi, Hisashi Takeda, Takashi Yaguchi, Galba Maria de Campos Takaki, Tomoo Hosoe
    HETEROCYCLES 94(2) 326-333 2017年2月  
    New two pebrolide type sesquiterpenoids, deacetoxy-1-deoxypebrolide (1) and 7'-hydroxyisoasperphenamate (2) along with asperphenamate (3), mycophenolic acid (4) and 1-deoxypebloride (5) were isolated from Penicillium sp. IFM 62525. Their structures were established from spectroscopic and chemical method. The absolute stereochemistry of 2 was confirmed by Marfey's method. Antifungal activities of these compounds were tested and 4 showed strong activity.
  • Daisuke Motooka, Kosuke Fujimoto, Reiko Tanaka, Takashi Yaguchi, Kazuyoshi Gotoh, Yuichi Maeda, Yoki Furuta, Takashi Kurakawa, Naohisa Goto, Teruo Yasunaga, Masashi Narazaki, Atsushi Kumanogoh, Toshihiro Horii, Tetsuya Iida, Kiyoshi Takeda, Shota Nakamura
    FRONTIERS IN MICROBIOLOGY 8 2017年2月  
    The study of mycobiota remains relatively unexplored due to the lack of sufficient available reference strains and databases compared to those of bacterial microbiome studies. Deep sequencing of Internal Transcribed Spacer (ITS) regions is the de facto standard for fungal diversity analysis. However, results are often biased because of the wide variety of sequence lengths in the ITS regions and the complexity of high-throughput sequencing (HTS) technologies. In this study, a curated ITS database, ntF-ITS1, was constructed. This database can be utilized for the taxonomic assignment of fungal community members. We evaluated the efficacy of strategies for mycobiome analysis by using this database and characterizing a mock fungal community consisting of 26 species representing 15 genera using ITS1 sequencing with three HTS platforms: Illumina MiSeq (MiSeq), Ion Torrent Personal Genome Machine (IonPGM), and Pacific Biosciences (PacBio). Our evaluation demonstrated that PacBio's circular consensus sequencing with greater than 8 full-passes most accurately reconstructed the composition of the mock community. Using this strategy for deep-sequencing analysis of the gut mycobiota in healthy Japanese individuals revealed two major mycobiota types: a single-species type composed of Candida albicans or Saccharomyces cerevisiae and a multi-species type. In this study, we proposed the best possible processing strategies for the three sequencing platforms, of which, the PacBio platform allowed for the most accurate estimation of the fungal community. The database and methodology described here provide critical tools for the emerging field of mycobiome studies.
  • Yasunors Muraosa, Mssato Oguchs, Maks Yahsro, Aksra Watanabe, Takashs Yaguchs, Katsuhsko Kames
    Medical Mycology Journal 58(1) E5-E13 2017年  査読有り
    In Japan, Fusarium species are known etiological agents of human fungal infection however, there has been no report of a large-scale epidemiological study on the etiological agents of fusariosis. A total of 73 Fusarium isolates from patients with invasive fusariosis (IF, n = 36) or superficial fusariosis (SF, n = 37), which were obtained at hospitals located in 28 prefectures in Japan between 1998 and 2015, were used for this study. Fusarium isolates were identified using Fusarium- and Fusarium solani species complex (FSSC)-specific real-time PCR and partial DNA sequences of the elongation factor-1 alpha (EF-1α) gene and the nuclear ribosomal internal transcribed spacer (ITS)region. FSSC was predominately isolated from both patients with IF and SF (IF, 77.8% and SF, 67.6%). Distribution of the phylogenetic species of FSSC isolates from patients with IF and SF exhibited different spectra specifically, F. keratoplasticum (FSSC 2) (25.0%)was the most frequent isolate from patients with IF, whereas F. falciforme (FSSC 3+ 4) (32.4%)was the most frequent isolate from patients with SF. Fusarium sp. (FSSC 5)was the second most frequent isolate from both patients with IF and SF (IF, 22.2% and SF, 24.3%). Notably, F. petroliphilum (FSSC 1)was isolated only from patients with IF. Each species was isolated from a broad geographic area, and an epidemic was not observed. This is the first epidemiological study of Fusarium species causing IF and SF in Japan.
  • K. Notarte, Y. Nakao, T. Yaguchi, M. Bungihan, K. Suganuma, T. E. dela Cruz
    MYCOSPHERE 8(1) 111-120 2017年  
    Malformin A(1), a cyclic pentapeptide, was isolated from the marine-derived fungus Aspergillus tubingensis IFM 63452. The identity of the compound was established based on TOFMS and H-1 NMR data. Malformin A(1) exhibited trypanocidal activity against Trypanosoma congolense (IC50: 15.08 ng/mL). Interestingly, the compound was selective for T. congolense rendering a selectivity index value that ranged from 3.33 to 4.67. It also demonstrated cytotoxicity against HeLa (IC50: 50.15 ng/mL) and P388 (IC50: 70.38 ng/mL) cell lines. To further identify the possible mechanism of its cytotoxic effect, immunofluorescence staining was conducted to follow the epigenetic changes induced by the compound in the amino acid lysine of histone H3 and H4 in HeLa. The compound induced repressive levels of H3K27me3, H3K27ac and H4K5ac, and enhanced levels of H3K9me2, H3K9me3 and H4K16ac supporting the compound's chemotherapeutic potential.
  • Yumi Imanishi, Reiko Tanaka, Takashi Yaguchi, Kiminori Shimizu
    MYCOSCIENCE 58(1) 45-52 2017年1月  
    A basidiomycetous yeast Cryptococcus neoformans is stained by DBB. We found that the edges of DBB stained cells were specifically detected by using fluorescence microscopy. We also found that the only the edges of cap64 Delta strain cells was not fluorescent among several acapsular mutants, although whose colonies turned to red or light pink by DBB staining. When the vacuoles were stained by FM4-64, those of the cap64 Delta cells showed aberrant morphology. In addition, quinacrine treatment showed that the cap64 Delta strain could not accumulate quinacrine in the vacuole. These data suggest that Cap64 was not only involved in capsule formation, but also in intracellular pH regulation. (C) 2016 The Mycological Society of Japan. Published by Elsevier B.V. All rights reserved.
  • Hou-Min Li, Yumi Shimizu-Imanishi, Reiko Tanaka, Ruo-Yu Li, Takashi Yaguchi
    CHINESE MEDICAL JOURNAL 129(22) 2725-2732 2016年11月  
    Background: Candida albicans (C. albicans) can become a pathogen causing superficial as well as life-threatening systemic infections, especially in immunocompromised patients. Many phenotypic attributes contribute to its capacity to colonize human organs. In our study, 93 C. albicans isolates from patients of various candidiasis in a hospital of China were surveyed. We aimed to investigate the white-opaque (WO) switching competence, drug sensitivity, and virulence of mating type-like (MTL) a/alpha isolates. Methods: Internal transcribed spacer (ITS) gene and the MTL configuration were detected in all the isolates by reverse transcription-polymerase chain reaction. White/opaque phenotype and doubling time of cell growth were determined. The minimum inhibitory concentrations of antifungal agent were measured using broth microdilution method. Results: Sixty-four isolates (69.6%) were classified to serotype A, 19 (20.6%) to serotype B, and 9 (9.8%) to serotype C. Moreover, phylogenetic analysis showed that these isolates were divided into four different subgroups of ITS genotypes. Most of our clinical isolates were MTLa/alpha type, while 6.8% remained MTLa or MTL alpha type. The frequency of opaque phenotype was 71.0% (66 isolates). Following the guidelines of Clinical and Laboratory Standards Institute M27-A3, all isolates were susceptible to caspofungin and a few (0.6-3.2%) of them showed resistance against amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole. Conclusions: From these analyses, there were comparatively more C. albicans strains classified into serotype B, and the frequency of opaque phase strains was significant in the clinical isolates from China. Genetic, phenotypic, or drug susceptibility patterns were not significantly different from previous studies. MTLa/alpha isolates could also undergo WO switching which facilitates their survival.
  • 橋本 亜希, 萩原 大祐, 渡辺 哲, 矢口 貴志, 亀井 克彦, 広瀬 大
    Medical Mycology Journal 57(Suppl.1) 104-104 2016年9月  
  • Takehisa Matsumoto, Tatsuya Negishi, Moriyuki Hamada, Hisayuki Komaki, Tohru Gonoi, Takashi Yaguchi
    INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 66 3324-3328 2016年9月  
    A nocardioform strain IFM 11456(T) was isolated from the aqueous humor from a patient with endophthalmitis and was characterized to its taxonomic position. IFM 11456(T) contained arabinose, galactose and meso-diaminopimelic acid in whole-cell hydrolysates and mycolic acids that co-migrated with those from the type strain of Nocardia asteroides. The acyl type of muramic acid was N-glycolyl. The diagnostic polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and two unidentified glycolipids and the predominant menaquinone was MK-8 (H-4, omega-cycl.). These characteristics are typical of members of the genus Nocardia. Results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the isolate represented a novel species of the genus Nocardia and was most closely related to the type strains of Nocardia mikamii JCM 15508(T) (98.1 %) and Nocardia aobensis IFM 0372(T) (98.1 %). However, analysis of partial gyrB sequences showed that strain IFM 11456(T) had 90.2% similarity to Nocardia concava IFM 0354(T) and 90% to Nocardia niigatensis IFM 0330(T). The DNA-DNA relatedness values for strain IFM 11456(T) compared with N. mikamii JCM 15508(T), N. aobensis IFM 0372(T) and N. concava IFM 0354(T) ranged from 24.4 to 39.9 %. Phenotypic characteristics that differentiated IFM 11456(T) from phylogenetically related species were growth at 45 degrees C, utilization of citrate and growth with inositol as a sole carbon source. On the basis of this polyphasic study, the isolate represents a novel species within the genus Nocardia, for which the name Nocardia shinanonensis sp. nov. is proposed. The type strain is IFM 11456(T) (= NBRC 109590(T) = TBRC 5149(T)).
  • Kazuki Ishikawa, Fumiaki Sato, Takeshi Itabashi, Hiroshi Wachi, Hisashi Takeda, Daigo Wakana, Takashi Yaguchi, Ken-ichi Kawai, Tomoo Hosoe
    JOURNAL OF NATURAL PRODUCTS 79(9) 2167-2174 2016年9月  
    Seven novel spiromeroterpenoids, asnovolins A-G (1-7), one of which was shown to suppress fibronectin expression, were isolated from Aspergillus novofumigatus CBS117520 along with a known compound, novofumigatonin (8). The structures of asnovolins A-G were elucidated using MS and 2D-NMR data. Asnovolin E (5) suppressed fibronectin expression by normal human neonatal dermal fibroblast cells.
  • Toru Kuboi, Kaoru Okazaki, Motohiro Inotani, Masashiro Sugino, Takaaki Sadamura, Akiko Nakano, Shoko Kobayashi, Akira Ota, Keiko Nishimura, Takashi Yaguchi
    JOURNAL OF INFECTION AND CHEMOTHERAPY 22(5) 339-341 2016年5月  
    Background: Many types of weak pathogenic microorganisms often cause opportunistic infections in extremely preterm infants. Paecilomyces formosus is one such opportunistic fungus that can lead to a serious infection. Here, we report the clinical course of P. formosus infection in an extremely preterm infant. Case presentation: An extremely preterm male infant was born at 23 weeks of gestation. Six days after birth, he developed yellowish-brown nodules on the skin of the back extending to the buttocks. P. formosus was identified by culture of samples from the cutaneous lesions. We treated the infection with intravenous micafungin and lanoconazole ointment application. The skin lesions improved dramatically and healed without scar tissue formation. Conclusion: Neonatologists should consider opportunistic P. formosus infections. This is the first report to describe that micafungin is effective for P. formosus cutaneous infection in extremely premature infants. (C) 2015, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
  • Akiko Ogawa, Yukihiro Matsumoto, Takashi Yaguchi, Shigeto Shimmura, Kazuo Tsubota
    JOURNAL OF INFECTION AND CHEMOTHERAPY 22(4) 257-260 2016年4月  
    We describe a 66-year-old woman who suffered from fungal keratitis after corneal transplantation. The causative organism was identified as Beauveria bassiana on the basis of morphological characteristics and the sequence of the internal transcribed spacer region of the ribosomal RNA gene. The patient was successfully treated with topical voriconazole (VRCZ) use only. We, hereby, present the first report of a case with B. bassiana fungal keratitis that responded to topical antifungal VRCZ treatment. (C) 2015, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
  • Naruhiko Ishiwada, Kenichi Takeshita, Takashi Yaguchi, Koo Nagasawa, Noriko Takeuchi, Haruka Hishiki, Akira Watanabe, Katsuhiko Kamei, Naoki Shimojo
    MYCOPATHOLOGIA 181(3-4) 305-309 2016年4月  
    A 16-year-old boy with chronic granulomatous disease presented with pneumonia and rib osteomyelitis. Emericella nidulans var. echinulata was isolated from his sputum. After starting voriconazole, Rasamsonia piperina was isolated from the rib swelling. A combination therapy of voriconazole and micafungin effectively eradicated this invasive mixed-mold infection. In immunocompromised patients, a precise pathogenic diagnosis is clinically useful for administration of an appropriate treatment regimen.
  • Tomonari Shigemura, Sayaka Nishina, Hideyuki Nakazawa, Kazuyuki Matsuda, Takashi Yaguchi, Yozo Nakazawa
    INTERNATIONAL JOURNAL OF HEMATOLOGY 103(3) 354-355 2016年3月  
  • Tetsuya Saito, Takeshi Itabashi, Daigo Wakana, Hisashi Takeda, Takashi Yaguchi, Ken-ichi Kawai, Tomoo Hosoe
    JOURNAL OF ANTIBIOTICS 69(2) 89-96 2016年2月  
    Three new phthalide derivatives, emefuranones A(1), A(2) and B (1-3); six new phthalane derivatives, emefuran A, B-1, B-2, C-1, C-2 and D (4-9); three new farnesylated phthalide derivatives, farnesylemefuranones A-C (10-12); xylarinol C (13); and emericelloxide (14), along with four known compounds (dustanin, sorbicillin, aspergillodiol and xylarinol A), were isolated from the culture extracts of Emericella sp. IFM57991. Structures of 1-14 were elucidated on the basis of spectroscopic analysis and chemical evidence. Compounds 4-7 and 13 showed moderate antibacterial activities against Bacillus subtilis.
  • Suzuki R, Yikelamu A, Tanaka R, Igawa K, Yokozeki H, Yaguchi T
    Medical Mycology Journal 57(3) E47-57 2016年1月  査読有り
    Owner : NLM<br /> Status : In-Data-Review<br /> PubModel : Print<br /> Language : ENG<br /> Pagination : E47-57
  • Nakamura S, Sato H, Tanaka R, Yaguchi T
    Mass Spectrometry 5 A0049 2016年  査読有り
  • Sunada A, Asari S, Inoue Y, Ohashi Y, Suzuki T, Shimomura Y, Fukuda M, Sotozono C, Hatano H, Eguchi H, Araki-Sasaki K, Hoshi S, Yaguchi T, Makimura K, Yokokura S, Mochizuki K, Monden Y, Nejima R, Multicenter Study, Group of Fungal, Keratitis in Japan
    Nippon Ganka Gakkai zasshi 120(1) 17-27 2016年1月  査読有り
  • Yoko Kusuya, Kanae Sakai, Katsuhiko Kamei, Hiroki Takahashi, Takashi Yaguchi
    Genome Announcements 4(1) 2016年  
    Aspergillus lentulus, a sibling species of Aspergillus fumigatus, has been reported as a causative agent of aspergillosis, and exhibited low susceptibility to azole. Here, we present the draft genome sequence of A. lentulus strain IFM 54703T for the first time.
  • Rumi Suzuki, Alimu Yikelamu, Reiko Tanaka, Ken Igawa, Hiroo Yokozeki, Takashi Yaguchi
    Japanese Journal of Medical Mycology 57(3) 47-57 2016年  
    Sporotrichosis is a fungal infection caused by the Sporothrix species, which have distinct virulence profiles and geographic distributions. We performed a phylogenetic study in strains morphologically identified as Sporothrix schenckii from clinical specimens in Japan, which were preserved at the Medical Mycology Research Center, Chiba University. In addition, we examined the in vitro antifungal susceptibility and growth rate to evaluate their physiological features. Three hundred strains were examined using sequence analysis of the partial calmodulin gene, or polymerase chain reaction(PCR) method using newly designed species-specific primers 291 strains were Sporothrix globosa and 9 strains were S. schenckii sensu stricto(in narrow sense, s. s.). S. globosa strains were further clustered into two subclades, and S. schenckii s. s. strains were divided into three subclades. In 38 strains of S. globosa for which antifungal profiles were determined, 4 strains(11%)showed high minimal inhibitory concentration(MIC)value for itraconazole. All tested strains of S. schenckii s. s. and S. globosa showed low sensitivity for amphotericin B. These antifungals are used for treatment of sporotrichosis when infection is severe. S. schenckii s. s. grew better than S. globosa wherein S. globosa showed restricted growth at 35? and did not grow at 37�C. Our molecular data showed that S. globosa is the main causal agent of sporotrichosis in Japan. It is important to determine the antifungal profiles of each case, in addition to accurate species-level identification, to strategize the therapy for sporotrichosis.
  • Motokazu Nakayama, Kouichi Hosoya, Yumi Shimizu-Imanishi, Hiroji Chibana, Takashi Yaguchi
    Biocontrol science 21(2) 73-80 2016年  
    The number of spoilage incidents in the food industry attributable to a species of the genus Moniliella has recently increased, but the risk of food spoilage has not yet been evaluated. The purpose of this study was to develop a method to rapidly identify high-risk species and to conduct a risk analysis study of Moniliella spp. Acetic acid resistance of M. acetoabutens and ethanol resistance of M. suaveolens were higher than for other Moniliella species. All examined strains of M. acetoabutens developed a high tolerance to acetic acid by being cultured twice in liquid media containing low concentrations of acetic acid. These findings indicate that M. acetoabutens and M. suaveolens are high-risk species for food spoilage and must be discriminated from other fungi. We developed species-specific primers to identify M. acetoabutens and M. suaveolens using the polymerase chain reaction (PCR) to amplify the D1/D2 domain of 28S rDNA. The PCR using the primer sets designed for M. acetoabutens (Mac_F1/R1) and M. suaveolens (Msu_F1/R1) was specific to the target species and did not detect other fungi involved in food spoilage or environmental contamination. This method is expected to be effective for the monitoring of raw materials and components of the food production process.
  • 橋本 亜希, 渡辺 哲, 萩原 大祐, 矢口 貴志, 亀井 克彦
    Medical Mycology Journal 56(Suppl.1) 87-87 2015年9月  
  • Shigeto Yanagihara, Hiromi Kobayashi, Riei Kamo, Chika Hirata, Masataro Hiruma, Kazuko Nishimura, Takashi Yaguchi, Yuichi Yoshida, Osamu Yamamoto, Daisuke Tsuruta
    JOURNAL OF DERMATOLOGY 42(8) 833-834 2015年8月  
  • Catarina Costa, Andreia Ponte, Pedro Pais, Rui Santos, Mafalda Cavalheiro, Takashi Yaguchi, Hiroji Chibana, Miguel Cacho Teixeira
    PLOS ONE 10(8) 2015年8月  
    5-Flucytosine is currently used as an antifungal drug in combination therapy, but fungal pathogens are rapidly able to develop resistance against this drug, compromising its therapeutic action. The understanding of the underlying resistance mechanisms is crucial to deal with this problem. In this work, the S. cerevisiae deletion mutant collection was screened for increased resistance to flucytosine. Through this chemogenomics analysis, 183 genes were found to confer resistance to this antifungal agent. Consistent with its known effect in DNA, RNA and protein synthesis, the most significant Gene Ontology terms over-represented in the list of 5-flucytosine resistance determinants are related to DNA repair, RNA and protein metabolism. Additional functional classes include carbohydrate and nitrogen-particularly arginine-metabolism, lipid metabolism and cell wall remodeling. Based on the results obtained for S. cerevisiae as a model system, further studies were conducted in the pathogenic yeast Candida glabrata. Arginine supplementation was found to relieve the inhibitory effect exerted by 5-flucytosine in C. glabrata. Lyticase susceptibility was found to increase within the first 30min of 5-flucytosine exposure, suggesting this antifungal drug to act as a cell wall damaging agent. Upon exponential growth resumption in the presence of 5-flucytosine, the cell wall exhibited higher resistance to lyticase, suggesting that cell wall remodeling occurs in response to 5-flucytosine. Additionally, the aquaglyceroporin encoding genes CgFPS1 and CgFPS2, from C. glabrata, were identified as determinants of 5-flucytosine resistance. CgFPS1 and CgFPS2 were found to mediate 5-flucytosine resistance, by decreasing 5-flucytosine accumulation in C. glabrata cells.
  • Hiroyuki Tamiya, Eri Ochiai, Kazuyo Kikuchi, Maki Yahiro, Takahito Toyotome, Akira Watanabe, Takashi Yaguchi, Katsuhiko Kamei
    JOURNAL OF INFECTION AND CHEMOTHERAPY 21(5-6) 385-391 2015年5月  
    The incidence of Aspergillus infection has been increasing in the past few years. Also, new Aspergillus fumigatus-related species, namely Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans, were shown to infect humans. These fungi exhibit marked morphological similarities to A. fumigatus, albeit with different clinical courses and antifungal drug susceptibilities. The present study used liquid chromatography/time-of-flight mass spectrometry to identify the secondary metabolites secreted as virulence factors by these Aspergillus species and compared their antifungal susceptibility. The metabolite profiles varied widely among A. fumigatus, A. lentulus, A. udagawae, and A. viridinutans, producing 27, 13, 8, and 11 substances, respectively. Among the mycotoxins, fumifungin, fumiquinazoline A/B and D, fumitremorgin B, gliotoxin, sphingofungins, pseurotins, and verruculogen were only found in A. fumigatus, whereas auranthine was only found in A. lentulus. The amount of gliotoxin, one of the most abundant mycotoxins in A. fumigatus, was negligible in these related species. In addition, they had decreased susceptibility to antifungal agents such as itraconazole and voriconazole, even though metabolites that were shared in the isolates showing higher minimum inhibitory concentrations than epidemiological cutoff values were not detected. These strikingly different secondary metabolite profiles may lead to the development of more discriminative identification protocols for such closely related Aspergillus species as well as improved treatment outcomes. (C) 2015, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
  • 矢口 貴志, 田中 玲子, 渡辺 哲, 亀井 克彦, 五ノ井 透, 伊藤 純子, 鎗田 響子
    感染症学雑誌 89(2) 340-340 2015年3月  
  • Tetsuhiro Matsuzawa, Galba M. Campos Takaki, Takashi Yaguchi, Kaoru Okada, Paride Abliz, Tohru Gonoi, Yoshikazu Horie
    MYCOSCIENCE 56(2) 123-131 2015年3月  
    Aspergillus arcoverdensis, a new species isolated from semi-desert soil in a caatinga area, State of Pernambuco, Brazil, and a similar environment in the Xinjiang Uygur Autonomous Region, China, is described and illustrated. It is characterized by relatively long co-nidiophores for Aspergillus section Fumigati, and subglobose to broadly ellipsoidal and smooth conidia. The delimitation of this new species is supported further by phylogenetic analyses of the beta-tubulin, calmodulin and actin gene sequences. (C) 2014 The Mycological Society of Japan. Published by Elsevier B.V. All rights reserved.
  • Hiroshi Eguchi, Toshi Toibana, Fumika Hotta, Tatsuro Miyamoto, Yoshinori Mitamura, Takashi Yaguchi
    MYCOSES 58(2) 88-92 2015年2月  
    To date, there has been only one published report on the infectious sclerokeratitis caused by Metarhizium anisopliae, which is an entomopathogenic fungus. Regarding corneal infection, three reports have been published to date. Although the prognoses of the corneal infections are favourable, prognosis when scleral infection is involved is very poor. A 76-year-old patient presented with foreign body sensation in the left eye. Microscopic examination with Fungi Flora Y staining of the corneal scraping revealed fungal infection. The conjunctiva was melted by the infection over a wide area. Although intensive medications were administered, an emergency surgery was necessary because scleral thinning, corneal perforation and lens prolapse occurred. The fungal isolate was identified as M. anisopliae by sequencing the internal transcribed spacer region. Herein, we report the second known case worldwide of M. anisopliae sclerokeratitis, and we review the literature related to the ocular infections.
  • 比留間 淳一郎, 宇野 潤, 原田 和俊, 矢口 貴志, 比留間 政太郎, 知花 博治
    日本医真菌学会総会プログラム・抄録集 56 96-96 2015年  査読有り
  • Magdalena Frac, Stefania Jezierska-Tys, Takashi Yaguchi
    ADVANCES IN AGRONOMY, VOL 132 132 161-204 2015年  
    Heat-resistant fungi are often factors causing spoilage of heat-processed products. Contamination of agricultural raw materials is often a result of their contact with soil. Materials contaminated by spores of heat-resistant fungi can be a risk to consumers' health because of toxic metabolites (mycotoxins) produced by these microorganisms. Due to resistance of fungi to high temperatures they are able to survive industry pasteurization process. Therefore, the only way to prevent the growth of these microorganisms in the product is suitable selection of material by conducting tests for the presence of heat-resistant fungi. The use of traditional culture methods is long and, therefore, does not apply in the selection of raw materials for production. However, time is a critical factor in assessing the acceptance or rejection of a given batch of raw material, due to the necessity of processing it fresh, which is very important especially in the case of fruit.
  • Yoko Kusuya, Azusa Takahashi-Nakaguchi, Hiroki Takahashi, Takashi Yaguchi
    Genome Announcements 3(4) 2015年  
    The incidence of aspergillosis by Aspergillus infection has dramatically increased in recent years. Aspergillus udagawae, a species related to Aspergillus fumigatus, is known as an emerging pathogen of aspergillosis. Here, we present the draft genome sequence of A. udagawae strain IFM 46973T.
  • Ayako Okita, Hiroshi Yoshikawa, Takeru Yoshimura, Tatsuro Ishibashi, Takaaki Matsui, Takashi Yaguchi
    Japanese Journal of Clinical Ophthalmology 69 1551-1555 2015年1月1日  
    Purpose: To report a case of conjunctivitis due to Scedosporium apiospermum. Case: A 42-year-old female was referred to us for elevated lesion in the upper tarsal conjunctiva in the right eye. She was a habitual wearer of hard contact lens. She had been diagnosed with allergic conjunctivitis 2 years before and been treated with topical corticosteroid and antibiotics. The eye discharge turned yellow 3 months before. Findings: The right eye showed copious discharge and hyperemic elevation in the upper tarsal conjunctiva. Excisional biopsy showed inflammatory granulation and fungal balls. The causative organism was identified as S. apiospermum. The symptoms disappeared after resection of granular tissue and topical voriconazol for 3 months. Conclusion: This case illustrates that fungal organism may underlie in refractory conjunctivitis.
  • 井上 幸次, 大橋 裕一, 下村 嘉一, 矢口 貴志, 槇村 浩一, 砂田 淳子, 浅利 誠志, 真菌性角膜炎多施設スタディグループ
    日本眼科学会雑誌 118(11) 977-977 2014年11月  
  • 渡辺 哲, 矢口 貴志, 亀井 克彦, 菊池 和代, 伊藤 純子, 奥 幸夫, 萩原 大祐, 鎗田 響子, 川本 進
    感染症学雑誌 88(5) 781-781 2014年9月  
  • Yuki Hayashi, Hiroshi Eguchi, Toshi Toibana, Yoshinori Mitamura, Takashi Yaguchi
    Cornea Vol.33(No.8) 875-877 2014年8月  査読有り
    The aim of this study was to report the first case of polymicrobial fungal sclerokeratitis caused by infection with both Scedosporium apiospermum and Aspergillus cibarius, and notify the medical community of the possibility of infection caused by A. cibarius in humans. A 78-year-old woman presented to a medical practitioner with epiphora and a purulent discharge in her left eye. After concurrent administration of topical antibiotics and systemic steroids, her symptoms worsened, and she was referred to the Tokushima University Hospital. Because of suspected fungal infection, microscopic examination and cultivation of both corneal and scleral scrapings were performed. Fungi were observed on microscopic examination, and S. apiospermum was isolated only from the sclera in the early stage of the clinical course. Although administration of an adequate medication regimen comprising topical and systemic antifungal drugs resulted in an improvement in the sclera, keratitis persisted, and the infected sclera was melted. After scleral transplantation, administration of systemic caspofungin and high concentrations of voriconazole solution eye drops resulted in a gradual improvement in keratitis. A strain of filamentous fungus was isolated from the cornea 6 weeks after the cultivation on a Sabouraud agar plate, and it was identified as A. cibarius. A. cibarius may infect human tissue. Coinfection of the cornea and the sclera with 2 different species of fungi is likely to follow a complex clinical course.
  • Daigo Wakana, Takeshi Itabashi, Ken-ichi Kawai, Takashi Yaguchi, Kazutaka Fukushima, Yukihiro Goda, Tomoo Hosoe
    JOURNAL OF ANTIBIOTICS 67(8) 585-588 2014年8月  
  • Tomonari Shigemura, Yozo Nakazawa, Kazuyuki Matsuda, Kenji Sano, Takashi Yaguchi, Mitsuo Motobayashi, Shoji Saito, Shunsuke Noda, Norimoto Kobayashi, Kazunaga Agematsu, Takayuki Honda, Kenichi Koike
    INTERNATIONAL JOURNAL OF HEMATOLOGY 100(2) 206-209 2014年8月  
    Mucormycosis is a fatal complication in immunocompromised patients, and is additionally difficult to diagnose due to the lack of useful serum biomarkers. Using a quantitative PCR approach, we retrospectively analyzed Mucorales DNA load in sera collected serially from a 3-year-old patient with chronic granulomatous disease, who died of multi-organ failure probably due to dissemination of Rhizomucor pusillus, which was detected from necropsy specimens. Mucorales DNA load was below the detection limit on days 9, 2, and 4 after unrelated bone marrow transplantation. Rhizomucor DNA was first detected on day 14 (1.6 x 10(3) copies/mL), and subsequently fluctuated between 1.3 x 10(3) and 37.2 x 10(3) copies/mL until day 43. Rhizomucor achieved a peak value of 940.0 x 10(3) copies/mL on day 48 the day before death. The detection or fluctuation of Rhizomucor DNA appeared to be associated with corticosteroid dosages or C-reactive protein levels. This specific, noninvasive, and highly quantitative assay may be useful for the early diagnosis of mucormycosis and prediction of disease progression.
  • Satoko Kokuzawa, Shinsuke Suemori, Kiyofumi Mochizuki, Yoshinobu Hirose, Takashi Yaguchi
    SEMINARS IN OPHTHALMOLOGY 29(4) 218-221 2014年7月  
    An 88-year-old man underwent uneventful phacoemulsification and aspiration with an implantation of a preloaded acrylic intraocular lens. Six months later, he developed endophthalmitis with negative aqueous cultures, and the inflammation was refractory to conventional antibacterial therapies. He was treated successfully with vitrectomy and removal of the IOL and the entire lens capsule. A combination of intravitreal voriconazole and systemic micafungin were prescribed, and the inflammation was resolved. As best we know, this is the first case of Aspergillus tubingenesis endophthalmitis that followed the implantation of a preloaded intraocular lens.
  • Kouichi Hosoya, Motokazu Nakayama, Daisuke Tomiyama, Tetsuhiro Matsuzawa, Yumi Imanishi, Seiichi Ueda, Takashi Yaguchi
    FOOD CONTROL 41 7-12 2014年7月  
    Recently the numbers of spoilage incidents in food industry by the species of Thermoascus are increasing, but the risk of food spoilage have never been evaluated. It became obvious that their heat-resistances were higher than those of other heat-resist fungi, Byssochlamys, Hamigera and Neosartoiya by our analyses. On the other hand, Thermoascus aurantiacus and Byssochlamys verrucosa had the idh gene, but they showed no patulin production in Potato dextrose broth or Czapek-glucose medium. Therefore, Thermoascus must be discriminated from other fungi in the food industry. We developed a rapid and highly-sensitive method of detecting Thermoascus in the genus level by using PCR. This method is expected to be extremely beneficial for the surveillance of raw materials in the food production process. (C) 2013 Elsevier Ltd. All rights reserved.
  • C. M. Visagie, J. Houbraken, J. C. Frisvad, S. -B. Hong, C. H. W. Klaassen, G. Perrone, K. A. Seifert, J. Varga, T. Yaguchi, R. A. Samson
    STUDIES IN MYCOLOGY 78(78) 343-371 2014年6月  
    Penicillium is a diverse genus occurring worldwide and its species play important roles as decomposers of organic materials and cause destructive rots in the food industry where they produce a wide range of mycotoxins. Other species are considered enzyme factories or are common indoor air allergens. Although DNA sequences are essential for robust identification of Penicillium species, there is currently no comprehensive, verified reference database for the genus. To coincide with the move to one fungus one name in the International Code of Nomenclature for algae, fungi and plants, the generic concept of Penicillium was re-defined to accommodate species from other genera, such as Chromocleista, Eladia, Eupenicillium, Torulomyces and Thysanophora, which together comprise a large monophyletic clade. As a result of this, and the many new species described in recent years, it was necessary to update the list of accepted species in Penicillium. The genus currently contains 354 accepted species, including new combinations for Aspergillus crystallinus, A. malodoratus and A. paradoxus, which belong to Penicillium section Paradoxa. To add to the taxonomic value of the list, we also provide information on each accepted species MycoBank number, living ex-type strains and provide GenBank accession numbers to ITS, beta-tubulin, calmodulin and RPB2 sequences, thereby supplying a verified set of sequences for each species of the genus. In addition to the nomenclatural list, we recommend a standard working method for species descriptions and identifications to be adopted by laboratories working on this genus.
  • R. A. Samson, C. M. Visagie, J. Houbraken, S. -B. Hong, V. Hubka, C. H. W. Klaassen, G. Perrone, K. A. Seifert, A. Susca, J. B. Tanney, J. Varga, S. Kocsube, G. Szigeti, T. Yaguchi, J. C. Frisvad
    STUDIES IN MYCOLOGY 78(78) 141-173 2014年6月  
    Aspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision. We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and GenBank accession numbers for available representative ITS, calmodulin, beta-tubulin and RPB2 sequences. In addition, we recommend a standard working technique for Aspergillus and propose calmodulin as a secondary identification marker.
  • 渡辺 哲, 矢口 貴志, 亀井 克彦, 菊池 和代, 伊藤 純子, 奥 幸夫, 萩原 大祐, 鎗田 響子, 川本 進
    日本化学療法学会雑誌 62(Suppl.A) 279-279 2014年5月  
  • Tetsuhiro Matsuzawa, Yoshikazu Horie, Paride Abliz, Tohru Gonoi, Takashi Yaguchi
    MYCOSCIENCE 55(3) 213-220 2014年5月  査読有り
    Aspergillus huiyaniae, a new teleomorphic species isolated from desert soil in Xinjiang, China, was described and illustrated. Aspergillus huiyaniae is characterized by its yellowish white to pale yellow cleistothecia, broadly lenticular ascospores with two equatorial crests and irregularly ribbed to slightly reticulate convex surfaces, and subglobose to ovate or broadly ellipsoidal conidia with smooth walls. This species was supported further by the analyses of the beta-tubulin, calmodulin and actin gene sequences. (C) 2013 The Mycological Society of Japan. Published by Elsevier B. V. All rights reserved.
  • Kazuyo Kikuchi, Akira Watanabe, Junko Ito, Yukio Oku, Tuya Wuren, Hideaki Taguchi, Kyoko Yarita, Yasunori Muraosa, Maki Yahiro, Takashi Yaguchi, Katsuhiko Kamei
    JOURNAL OF INFECTION AND CHEMOTHERAPY 20(5-6) 336-338 2014年5月  
    Azole resistance among clinical isolates of Aspergillus fumigatus is becoming a serious problem in Europe, but the status in Japan is not yet known in detail. The aim of this study was to determine the present status of azole resistance in A. fumigatus in Japan. We employed 171 clinical isolates of A. fumigatus sensu stricto collected from 1987 to 2008 at the Medical Mycology Research Center, Chiba University, Japan for azole resistance determination. Identification of all isolates were re-examined both from the aspect of morphology and molecular phylogeny. The antifungal susceptibility of these isolates was tested based on the CLSI M38-A2 broth microdilution method. In our collection, only 1 (0.6%) and 2 isolates (1.2%) showed elevated MIC to voriconazole and itraconazole, respectively. Our study disclosed that the frequency of azole resistance in A. fumigatus still remains low in this collection. (C) 2014, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
  • Tetsuhiro Matsuzawa, Galba M. Campos Takaki, Takashi Yaguchi, Kaoru Okada, Tohru Gonoi, Yoshikazu Horie
    MYCOSCIENCE 55(2) 79-88 2014年3月  査読有り
    Aspergillus caatingaensis and A. pernambucoensis, isolated from semi-desert soil in caatinga area, the State of Pernambuco, Brazil, are described and illustrated. Aspergillus caatingaensis is characterized by its white cleistothecia, broadly lenticular ascospores with four equatorial crests and irregularly ribbed to slightly reticulate with aculeate convex surfaces, and ellipsoidal to broadly ellipsoidal conidia with a smooth wall. Aspergillus pernambucoensis is characterized by its, white cleistothecia, lenticular ascospores with two equatorial crests and irregularly ribbed with tuberculate to verrucate convex surfaces, and ovoid to broadly ellipsoidal conidia with a smooth wall. The validation of these new species is supported further by analyses of the beta-tubulin, calmodulin and actin gene sequences. (C) 2013 The Mycological Society of Japan. Published by Elsevier B.V. All rights reserved.
  • Rui Kano, Erina Yoshida, Takashi Yaguchi, Vit Hubka, Kazushi Anzawa, Takashi Mochizuki, Atsuhiko Hasegawa, Hiroshi Kamata
    MYCOPATHOLOGIA 177(1-2) 87-90 2014年2月  
    Trichophyton verrucosum is a zoophilic dermatophyte species that is the most frequent etiologic agent of bovine dermatophytosis throughout the world. Since no teleomorph of T. verrucosum has been found, polymerase chain reaction (PCR) analysis on the genome of T. verrucosum isolated from the Czech Republic and Japan was performed to confirm the presence of a mating type locus in the genome of the fungus and to clarify its classification and ecological characteristics. The mating type gene (MAT1-2) allele was detected by PCR analysis in all 22 isolates (four isolates from the Czech Republic and 18 isolates from Japan). The nucleotide sequence of the region exhibited 99-100 % identity among all isolates, including the reference strain of T. verrucosum. Phylogenetic analysis revealed that the sequences of the internal transcribed spacer region at the MAT1-2 locus clustered together in the isolates examined, forming a branch distinct from that of the other dermatophyte species. These results suggest that T. verrucosum is a clonal offshoot that has drifted away from Arthroderma benhamiae.
  • Toyozo SATO, Mutsuo AOKI, Takayuki AOKI, Masaharu KUBOTA, Takashi YAGUCHI, Shihomi UZUHASHI, Keisuke TOMIOKA
    Japan Agricultural Research Quarterly: JARQ 48(3) 317-329 2014年  
    The morphology of 18 and seven species of fungi isolated from spoiled bean sprouts of Vigna spp. and soybean in Japan were respectively described, and DNA barcode markers of most isolates were sequenced to confirm the morphological identification. Fifteen and five species were isolated for the first time from Vigna spp. and soybean sprouts, including their ingredient grains, respectively. Globisporangium ultimum var. ultimum was newly recorded from the mung bean and most isolated fungi seemed to originate from the grains. Approximately 70% of isolates are recognized as plant pathogens and at least 14 species are known to be seed-borne. Inoculation experiments with representative strains of each species are needed to estimate the risks to bean sprout production and crop protection. Some strains of Fusarium graminearum isolated from the soybean were already reported as producing high concentrations of deoxynivalenol. Aspergillus flavus, which was found in mung bean sprouts, is a well-known aflatoxin producer. The ingredient grains should be imported after complete sterilization to avoid hazards; not only to bean sprout production but to human health. The effects of previously used sterilization techniques should be re-examined with the strains of various fungi isolated in this study to make them more practical.
  • Yuki Hayashi, Hiroshi Eguchi, Toshi Toibana, Yoshinori Mitamura, Takashi Yaguchi
    Cornea 33(8) 875-877 2014年  
    PURPOSE:: The aim of this study was to report the first case of polymicrobial fungal sclerokeratitis caused by infection with both Scedosporium apiospermum and Aspergillus cibarius, and notify the medical community of the possibility of infection caused by A. cibarius in humans. METHODS:: A 78-year-old woman presented to a medical practitioner with epiphora and a purulent discharge in her left eye. After concurrent administration of topical antibiotics and systemic steroids, her symptoms worsened, and she was referred to the Tokushima University Hospital. Because of suspected fungal infection, microscopic examination and cultivation of both corneal and scleral scrapings were performed. RESULTS:: Fungi were observed on microscopic examination, and S. apiospermum was isolated only from the sclera in the early stage of the clinical course. Although administration of an adequate medication regimen comprising topical and systemic antifungal drugs resulted in an improvement in the sclera, keratitis persisted, and the infected sclera was melted. After scleral transplantation, administration of systemic caspofungin and high concentrations of voriconazole solution eye drops resulted in a gradual improvement in keratitis. A strain of filamentous fungus was isolated from the cornea 6 weeks after the cultivation on a Sabouraud agar plate, and it was identified as A. cibarius. CONCLUSIONS:: A. cibarius may infect human tissue. Coinfection of the cornea and the sclera with 2 different species of fungi is likely to follow a complex clinical course. Copyright © 2014 by Lippincott Williams &amp Wilkins.
  • Hideaki Kawakami, Hiroko Inuzuka, Kiyofumi Mochizuki, Toshihiro Muto, Kiyofumi Ohkusu, Takashi Yaguchi, Yuka Yamagishi, Hiroshige Mikamo
    JOURNAL OF INFECTION AND CHEMOTHERAPY 20(1-2) 57-60 2014年1月  
    We describe a case of keratitis caused by Streptomyces thermocarboxydus and report the usefulness of molecular analysis in identifying the exact species of Streptomyces. A 50-year-old man was diagnosed with keratitis caused by Streptomyces sp. which was identified as S. thermocarboxydus by sequencing the 16S rDNA. He had no history of trauma or systemic diseases. He was initially treated with topical beta-lactams and fluoroquinolones, and systemic beta-lactams but the keratitis did not improve. His vision improved significantly after topical erythromycin (5 mg/ml and oral minocycline (200 mg/day) therapy. Our findings demonstrate that molecular analysis can be used to identify the exact Streptomyces species causing the keratitis. This then allowed us to determine the susceptibility of this species to different antibacterial drugs which were used to treat our patient successfully. (C) 2013, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
  • Alena Novakova, Vit Hubka, Zuzana Dudova, Tetsuhiro Matsuzawa, Alena Kubatova, Takashi Yaguchi, Miroslav Kolarik
    FUNGAL DIVERSITY 64(1) 253-274 2014年1月  
    The Aspergillus viridinutans complex includes morphologically similar, soil-inhabiting species. Although its species boundaries have not been fully defined, many isolates from the complex have been isolated as opportunistic human and animal pathogens. In the present study, these species were dominant in spoil sites subjected to various types of reclamation management after coal mining. These species were characterised using two different PCR-fingerprinting methods, sequence data from the beta-tubulin (benA) and calmodulin (caM) genes, macro- and micromorphology (optical and scanning electron microscopy), maximum growth temperatures and mating experiments. In addition, RNA polymerase II gene (RPB2), actin (act1) and ITS sequences were deposited for the ex-type isolates of newly described species. The mating experiment results, phylogenetic analyses and ascospore morphology suggested the presence of five species in the A. viridinutans complex. Aspergillus aureolus (syn. Neosartorya aureola) was the only homothallic species. Three species, A. felis, A. udagawae (syn. N. udagawae) and A. wyomingensis sp. nov., were heterothallic and their morphologically distinguishable teleomorph was induced by systematic mating experiments. Aspergillus viridinutans s. str. seems to be a very rare species and was represented only by the ex-type isolate in which the MAT1-1 locus was amplified. Aspegillus viridinutans and A. aureolus were typified in accordance with the rules of the new botanical code. Other species outside the A. viridinutans complex isolated from the reclamation sites were A. fumigatiaffinis and A. lentulus as well as two new sister species, A. brevistipitatus sp. nov. and A. conversis sp. nov. which were closely related each to other and to N. papuensis. Both new species are phylogenetically distant from all anamorphic species and resemble A. brevipes, A. duricaulis and A. unilateralis in micromorphology and are distinguishable from each other by the slower growth of A. conversis on all tested media. Interestingly, no isolate from the reclamation sites represented A. fumigatus s. str. which is usually reported as the dominant species from the section Fumigati in soil.

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  • 馬目照久, 中村文香, 原康雅, 原康雅, 高屋明子, 高屋明子, 高屋明子, 伴さやか, 高橋弘喜, 高橋弘喜, 矢口貴志, 石橋正己, 石橋正己
    日本薬学会年会要旨集(Web) 143rd 2023年  
  • 三宅真未, 原康雅, 原康雅, 渡邊圭一郎, 高屋明子, 高屋明子, 高屋明子, 矢口貴志, 石橋正己, 石橋正己
    日本薬学会年会要旨集(Web) 143rd 2023年  
  • 原康雅, 渡邊圭一郎, 高屋明子, 高屋明子, 馬目照久, 矢口貴志, 石橋正己
    日本生薬学会年会講演要旨集 68th 2022年  
  • 井上 幸次, 宮崎 大, 馬場 高志, 石倉 涼子, 松浦 一貴, 長谷川 晶子, 諸星 計, 小松 恵子, 小松 直樹, 唐下 千寿, 寺坂 祐樹, 富長 岳史, 三原 幸子, 宮野 佐智子, 佐々木 慎一, 川本 由紀美, 春木 智子, 井上 美智子, 大谷 史江, 稲田 耕大, 魚谷 竜, 清水 大輔, 三宅 瞳, 江原 二三枝, 郭 權慧, 矢倉 慶子, 清水 由美子, 大橋 裕一, 下村 嘉一, 臼井 正彦, 姚 玉峰, 外園 千恵, 井上 智之, 鈴木 崇, 加藤 四郎, 上田 重晴, 前田 一洋, 佐々木 裕美, 坂本 雅子, 山田 雅夫, 林 皓三郎, 塩田 洋, 綾塚 祐二, 佐々木 香る, 浅利 誠志, 砂田 淳子, 木村 圭吾, 福田 昌彦, 江口 洋, 秦野 寛, 細貝 真弓, 山上 聡, 海老原 伸行, 鈴木 弘, 星 最智, 横倉 俊二, 望月 清文, 槇村 浩一, 矢口 貴志, 錫谷 達夫, 小杉 伊三夫, 門田 遊, 子島 良平, 八木 彰子, 古川 敏仁
    日本眼科学会雑誌 124(3) 155-184 2020年3月  
    眼感染症と他の眼疾患の大きな違いは,他の眼疾患にはホストと環境の二つが関連しているが,眼感染症はホストと微生物と環境の三者が絡み合って疾患を形成してくることにある.それだけにより複雑であり,それを読み解き,解決を図っていくためには,さまざまな手法を駆使する必要がある.本論文では,我々が基礎から臨床までさまざまな方法で眼感染症に取り組んできたこと,取り組んでいることを紹介する.1.角膜ヘルペス Herpes simplex virus(HSV)による角膜炎はウイルスの増殖とウイルスに対する免疫反応との微妙なバランスで成り立っており,いまだ根本的な解決はなされておらず,臨床的な重要性は高い.そしてそれらの解決に向けて基礎研究の積み重ねが重要で,そこには最新の研究手法が応用できる.in vitroでは,角膜上皮細胞・角膜内皮細胞にHSVを感染させてmRNAをみるマイクロアレイで網羅的に発現遺伝子を解析し,その結果,重要性が判明した遺伝子の中で,interferon regulatory factor 7(IRF7)やindoleamine 2,3-dioxygenase 1(IDO1)のHSVに対する免疫反応への関与を解析してきた.in vivoではヘルペス制御に対するワクチンの試みやケモカイン受容体と角膜実質炎の関係,新しい抗ヘルペス薬アメナメビルの効果の可能性をマウスのHSV角膜炎モデルで検討してきた.臨床への研究手法の応用としてreal-time polymerase chain reaction(PCR)による診断を行ってきた.2.サイトメガロウイルス角膜内皮炎 2006年の小泉らの報告以来多くの研究・報告がなされているが,その病態はいまだ不明である.我々も臨床例における前房内のサイトメガロウイルス(CMV)-DNA量が種々の臨床的パラメーターと相関していること,CMVが角膜内皮細胞や線維柱帯細胞に実際に感染し,サイトカイン産生を含め,さまざまな反応を惹き起こしてくること,CMV感染角膜内皮細胞によるCD8陽性細胞傷害性T細胞誘導がCMV角膜内皮炎患者では低下していることなどを見出してきた.3.真菌性角膜炎多施設スタディ 日本眼感染症学会においてプロスペクティブな多施設観察研究として,起因真菌とその薬剤感受性・臨床所見や予後に関与する因子を検討した.多種多様な真菌が原因となっていることが,遺伝子解析で明らかとなり,in vitroの感受性検査では,ピマリシンとアゾール系の組み合わせで拮抗を示す株もあることが判明した.4.角膜感染症への人工知能応用の試み 現在多くの眼疾患への人工知能(AI)の応用が試みられており,今後日本眼科学会主導でAI研究が行われていくが,我々もImageNetデータベースの一般画像を用いて事前学習させた畳み込みニューラルネットワークというアルゴリズムに感染性角膜炎の細隙灯顕微鏡写真を学習させ,比較的良好な診断確度を得つつある.また,それと並行して細隙灯顕微鏡写真以外のデータ(培養・real-time PCR)を用いた診断モデルの構築もランダムフォレストなど別のアルゴリズムを用いて行っている.将来的にはこれを統合させることでAIによる診断が可能になると思われる.5.術後眼内炎予防 白内障術後眼内炎の予防についてはさまざまな試みが行われている.日本眼感染症学会主導の多施設スタディにおいて手術3日前からの抗菌点眼薬使用によって結膜嚢常在菌を減らすことができることを証明したが,その後ヨード製剤の術中使用や抗菌薬の前房内投与が行われるようになってきたこと,耐性菌対策が重要となってきたことなどから,術前抗菌点眼薬使用を見直す必要が出てきていると思われる.我々は術中ヨード製剤の使用によって,結膜嚢常在菌が減ること,また,術中ヨード製剤の使用が術前抗菌点眼薬使用に劣らない減菌効果を示すことをプロスペクティブスタディで証明した.これまで,眼感染症に関するさまざまな問題に対して研究が行われ,我々もそれに継続的に参画してきたが,今後も眼感染症は眼科臨床において重要な問題を提起し続けると思われ,最新の医学を貪欲に取り入れつつ,基礎から臨床にわたる幅広いアプローチでこの古くて新しい脅威に立ち向かっていく必要がある.(著者抄録)
  • 北原 博一, 稲本 伸子, 本田 治樹, 矢口 貴志, 佐藤 友隆
    臨床皮膚科 73(6) 435-439 2019年5月  
    <文献概要>77歳,男性.眉毛部の紅斑を主訴に受診.ステロイド外用にて治療開始したが,紅斑が増悪した.眉毛のKOH直接鏡検より菌糸を認め,顔面白癬と診断した.妻にMicrosporum canisによる顔面白癬で,テルビナフィン内服による加療歴があり,また敷地内に野良猫が複数おり容易に接触できる環境であったためM. canisによる顔面白癬を疑った.一方で患者の足趾爪甲に白濁病変があり,鏡検にて菌糸を認め爪白癬と診断した.顔面白癬の原因菌を同定するため,眉毛および爪から培養したところ,同様の集落を形成し,菌学的検査にて両者ともTrichophyton rubrumと確定した.顔面白癬の感染経路として,動物や柔道・レスリング選手同士などでの感染が報告される一方で,爪白癬などによる自家播種も考慮すべきであり,感染源特定に培養同定検査が有用であった1例を報告する.

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