151
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Ishii M, Matsumoto Y, Sekimizu K. Usefulness of silkworm as a host animal for understanding pathogenicity of Cryptococcus neoformans. Drug Discov Ther 2016; 10:9-13. [PMID: 26902902 DOI: 10.5582/ddt.2016.01015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We propose Cryptococcus neoformans infection model using silkworm for understanding cryptococcosis and screening of therapeutically effective antibiotics. Silkworm is an insect whose rearing methods were established through a long history of the sericulture industry. Silkworm facilitates experiments using a large number of individuals because of low cost for rearing and few ethical problems caused by killing animals. Silkworm can be reared at 37˚C to perform infection experiments at same temperature to human body. Injection of accurate amounts of samples into hemolymph of silkworm by usual syringes is easy to be done since silkworm has an appropriate size to handle. Moreover two injection methods, injection into hemolymph and intestine, are distinguishable for silkworms. The former is correspondent to intravenous injection, and the latter is to oral administration in humans. Taking these advantages of silkworms as host animals, it is possible to evaluate the virulence factors in C. neoformans and the therapeutic efficacy of antifungal agents.
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Affiliation(s)
- Masaki Ishii
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
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152
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Assembly and clustering of natural antibiotics guides target identification. Nat Chem Biol 2016; 12:233-9. [PMID: 26829473 DOI: 10.1038/nchembio.2018] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/09/2015] [Indexed: 12/25/2022]
Abstract
Antibiotics are essential for numerous medical procedures, including the treatment of bacterial infections, but their widespread use has led to the accumulation of resistance, prompting calls for the discovery of antibacterial agents with new targets. A majority of clinically approved antibacterial scaffolds are derived from microbial natural products, but these valuable molecules are not well annotated or organized, limiting the efficacy of modern informatic analyses. Here, we provide a comprehensive resource defining the targets, chemical origins and families of the natural antibacterial collective through a retrobiosynthetic algorithm. From this we also detail the directed mining of biosynthetic scaffolds and resistance determinants to reveal structures with a high likelihood of having previously unknown modes of action. Implementing this pipeline led to investigations of the telomycin family of natural products from Streptomyces canus, revealing that these bactericidal molecules possess a new antibacterial mode of action dependent on the bacterial phospholipid cardiolipin.
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153
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Affiliation(s)
- Hiroshi Tomoda
- Graduate School of Pharmaceutical Sciences, Kitasato University
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154
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Inagaki Y, Matsumoto Y, Sekimizu K. Using silkworms to establish alternative animal models for evaluation of drug-induced tissue injury. Drug Discov Ther 2016; 10:40-3. [DOI: 10.5582/ddt.2016.01023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Yoshinori Inagaki
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
| | - Yasuhiko Matsumoto
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
| | - Kazuhisa Sekimizu
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
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155
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Abstract
The practice of medicine was profoundly transformed by the introduction of the antibiotics (compounds isolated from Nature) and the antibacterials (compounds prepared by synthesis) for the control of bacterial infection. As a result of the extraordinary success of these compounds over decades of time, a timeless biological activity for these compounds has been presumed. This presumption is no longer. The inexorable acquisition of resistance mechanisms by bacteria is retransforming medical practice. Credible answers to this dilemma are far better recognized than they are being implemented. In this perspective we examine (and in key respects, reiterate) the chemical and biological strategies being used to address the challenge of bacterial resistance.
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Affiliation(s)
- Jed F. Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame IN 46556–5670, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame IN 46556–5670, USA
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156
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Klahn P, Brönstrup M. New Structural Templates for Clinically Validated and Novel Targets in Antimicrobial Drug Research and Development. Curr Top Microbiol Immunol 2016; 398:365-417. [PMID: 27704270 DOI: 10.1007/82_2016_501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The development of bacterial resistance against current antibiotic drugs necessitates a continuous renewal of the arsenal of efficacious drugs. This imperative has not been met by the output of antibiotic research and development of the past decades for various reasons, including the declining efforts of large pharma companies in this area. Moreover, the majority of novel antibiotics are chemical derivatives of existing structures that represent mostly step innovations, implying that the available chemical space may be exhausted. This review negates this impression by showcasing recent achievements in lead finding and optimization of antibiotics that have novel or unexplored chemical structures. Not surprisingly, many of the novel structural templates like teixobactins, lysocin, griselimycin, or the albicidin/cystobactamid pair were discovered from natural sources. Additional compounds were obtained from the screening of synthetic libraries and chemical synthesis, including the gyrase-inhibiting NTBI's and spiropyrimidinetrione, the tarocin and targocil inhibitors of wall teichoic acid synthesis, or the boronates and diazabicyclo[3.2.1]octane as novel β-lactamase inhibitors. A motif that is common to most clinically validated antibiotics is that they address hotspots in complex biosynthetic machineries, whose functioning is essential for the bacterial cell. Therefore, an introduction to the biological targets-cell wall synthesis, topoisomerases, the DNA sliding clamp, and membrane-bound electron transport-is given for each of the leads presented here.
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Affiliation(s)
- Philipp Klahn
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.
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157
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Paudel A, Hamamoto H, Panthee S, Sekimizu K. Menaquinone as a potential target of antibacterial agents. Drug Discov Ther 2016; 10:123-8. [DOI: 10.5582/ddt.2016.01041] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | | | | | - Kazuhisa Sekimizu
- Teikyo University Institute of Medical Mycology
- Genome Pharmaceuticals Institute Co., Ltd
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158
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Ishii K, Tabuchi F, Matsuo M, Tatsuno K, Sato T, Okazaki M, Hamamoto H, Matsumoto Y, Kaito C, Aoyagi T, Hiramatsu K, Kaku M, Moriya K, Sekimizu K. Phenotypic and genomic comparisons of highly vancomycin-resistant Staphylococcus aureus strains developed from multiple clinical MRSA strains by in vitro mutagenesis. Sci Rep 2015; 5:17092. [PMID: 26603341 PMCID: PMC4658547 DOI: 10.1038/srep17092] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 10/01/2015] [Indexed: 12/12/2022] Open
Abstract
The development of vancomycin (VCM) resistance in Staphylococcus aureus threatens global health. Studies of the VCM-resistance mechanism and alternative therapeutic strategies are urgently needed. We mutagenized S. aureus laboratory strains and methicillin-resistant S. aureus (MRSA) with ethyl methanesulfonate, and isolated mutants that exhibited high resistance to VCM (minimum inhibitory concentration = 32 μg/ml). These VCM-resistant strains were sensitive to linezolid and rifampicin, and partly to arbekacin and daptomycin. Beta-lactams had synergistic effects with VCM against these mutants. VCM-resistant strains exhibited a 2-fold increase in the cell wall thickness. Several genes were commonly mutated among the highly VCM-resistant mutants. These findings suggest that MRSA has a potential to develop high VCM resistance with cell wall thickening by the accumulation of mutations.
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Affiliation(s)
- Kenichi Ishii
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Fumiaki Tabuchi
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Miki Matsuo
- Department of Bacteriology, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Keita Tatsuno
- Department of Infection Control and Prevention, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tomoaki Sato
- Department of Infection Control and Prevention, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Mitsuhiro Okazaki
- Department of Medical Technology, School of Health Sciences, Tokyo University of Technology, Tokyo, Japan
| | - Hiroshi Hamamoto
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yasuhiko Matsumoto
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Chikara Kaito
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Tetsuji Aoyagi
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Tokyo, Japan
| | - Keiichi Hiramatsu
- Department of Bacteriology, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Mitsuo Kaku
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Tokyo, Japan
| | - Kyoji Moriya
- Department of Infection Control and Prevention, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazuhisa Sekimizu
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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159
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Nwibo DD, Hamamoto H, Matsumoto Y, Kaito C, Sekimizu K. Current use of silkworm larvae (Bombyx mori) as an animal model in pharmaco-medical research. Drug Discov Ther 2015; 9:133-5. [PMID: 25994065 DOI: 10.5582/ddt.2015.01026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We advocate the use of silkworm larvae, Bombyx mori, as an animal model for discovery of drug candidates. We have established several disease models using silkworms, which offer technical advantages in drug development and the study of host-pathogen interaction. This mini review briefly describes recent trends in the use of silkworm larvae as a non-mammalian model for drug discovery and it offers suggestions regarding the potential for silkworm use in pharmaceutical-biomedical research.
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Affiliation(s)
- Don Daniel Nwibo
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
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160
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161
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Seccareccia I, Kost C, Nett M. Quantitative Analysis of Lysobacter Predation. Appl Environ Microbiol 2015; 81:7098-105. [PMID: 26231654 PMCID: PMC4579460 DOI: 10.1128/aem.01781-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/28/2015] [Indexed: 02/01/2023] Open
Abstract
Bacteria of the genus Lysobacter are considered to be facultative predators that use a feeding strategy similar to that of myxobacteria. Experimental data supporting this assumption, however, are scarce. Therefore, the predatory activities of three Lysobacter species were tested in the prey spot plate assay and in the lawn predation assay, which are commonly used to analyze myxobacterial predation. Surprisingly, only one of the tested Lysobacter species showed predatory behavior in the two assays. This result suggested that not all Lysobacter strains are predatory or, alternatively, that the assays were not appropriate for determining the predatory potential of this bacterial group. To differentiate between the two scenarios, predation was tested in a CFU-based bioassay. For this purpose, defined numbers of Lysobacter cells were mixed together with potential prey bacteria featuring phenotypic markers, such as distinctive pigmentation or antibiotic resistance. After 24 h, cocultivated cells were streaked out on agar plates and sizes of bacterial populations were individually determined by counting the respective colonies. Using the CFU-based predation assay, we observed that Lysobacter spp. strongly antagonized other bacteria under nutrient-deficient conditions. Simultaneously, the Lysobacter population was increasing, which together with the killing of the cocultured bacteria indicated predation. Variation of the predator/prey ratio revealed that all three Lysobacter species tested needed to outnumber their prey for efficient predation, suggesting that they exclusively practiced group predation. In summary, the CFU-based predation assay not only enabled the quantification of prey killing and consumption by Lysobacter spp. but also provided insights into their mode of predation.
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Affiliation(s)
- Ivana Seccareccia
- Secondary Metabolism of Predatory Bacteria Junior Research Group, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Christian Kost
- Experimental Ecology and Evolution Research Group, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Markus Nett
- Secondary Metabolism of Predatory Bacteria Junior Research Group, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
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162
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Nwibo DD, Matsumoto Y, Sekimizu K. Identification and methods for prevention of Enterococcus mundtii infection in silkworm larvae, Bombyx mori, reared on artificial diet. Drug Discov Ther 2015; 9:184-90. [PMID: 26193940 DOI: 10.5582/ddt.2015.01036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Previously, it was reported that Enterococcus mundtii (E. mundtii) was associated with flacherie disease of silkworm larvae reared on artificial diet. In this study, we report that E. mundtii was isolated from diseased silkworm larvae, and validated as a pathogenic bacterium of the animal. When silkworm larva was infected with 1.04 × 10⁶ colony-forming units of E. mundtii via oral administration of diet, half population died within six days, indicating that the bacterium is pathogenic to silkworm. Less severe infection was found to cause anorexia and hamper the development of larvae. This pathogen was found to proliferate in both time- and dose-dependent manner in the gastrointestinal tract of the animal. The bacterium was isolated from powder of artificial diet made from mulberry leaves, and from mulberry leaves growing at a field. Minimum inhibitory concentration determination revealed that this bacterium was susceptible to tested antibiotics. Vancomycin treatment of diet significantly decreased the number of E. mundtii in intestine of silkworm larvae infected with the bacteria, compared to control. Furthermore, autoclaving or gamma ray irradiation of diet was also effective for exclusion of E. mundtii from the diet without the loss of its nutrient capacities. These results suggest that mulberry leaves used in making artificial diet for silkworm larvae is one of the sources of E. mundtii infection; and that antibiotic treatment, autoclaving or gamma ray irradiation of artificial diet can exclude the bacteria.
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Affiliation(s)
- Don Daniel Nwibo
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
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163
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Yang J, Yang Z, Yin Y, Rao M, Liang Y, Ge M. Three novel polyene macrolides isolated from cultures of Streptomyces lavenduligriseus. J Antibiot (Tokyo) 2015; 69:62-5. [PMID: 26174177 DOI: 10.1038/ja.2015.76] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/09/2015] [Accepted: 06/15/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Jiayue Yang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China.,Shanghai Laiyi Center for Biopharmaceutical R&D, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Zhijun Yang
- Shanghai Laiyi Center for Biopharmaceutical R&D, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Yu Yin
- Shanghai Laiyi Center for Biopharmaceutical R&D, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Min Rao
- Shanghai Laiyi Center for Biopharmaceutical R&D, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Yongheng Liang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Mei Ge
- Shanghai Laiyi Center for Biopharmaceutical R&D, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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164
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Abstract
The dramatic rise in microbial drug resistance in recent years has led to ongoing searches for novel drugs to add to the armory against infectious disease. Nevertheless, a paucity of new antibacterial drugs in discovery and development pipelines using traditional approaches has prompted a variety of unconventional and disruptive strategies for antibacterial drug discovery. Herein, we review recent nontraditional approaches that have been piloted for early drug discovery efforts. These unique methodologies open new avenues for finding the next generation of antimicrobials.
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Affiliation(s)
- Maya A Farha
- M.G. DeGroote Institute for Infectious Disease Research, and Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario, Canada
| | - Eric D Brown
- M.G. DeGroote Institute for Infectious Disease Research, and Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario, Canada
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165
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Inagaki Y, Matsumoto Y, Ishii M, Uchino K, Sezutsu H, Sekimizu K. Fluorescence imaging for a noninvasive in vivo toxicity-test using a transgenic silkworm expressing green fluorescent protein. Sci Rep 2015; 5:11180. [PMID: 26061948 PMCID: PMC4462092 DOI: 10.1038/srep11180] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 05/18/2015] [Indexed: 01/16/2023] Open
Abstract
In drug development, the toxicity of candidate chemicals must be carefully examined in an animal model. Here we developed a live imaging technique using silkworms for a noninvasive toxicity test applicable for drug screening. Injection of carbon tetrachloride, a tissue-injuring chemical, into transgenic silkworms expressing green fluorescent protein (GFP) induced leakage of GFP from the tissues into the hemolymph. The leakage of GFP was suppressed by pre-administration of either cimetidine, a cytochrome P450 inhibitor, or N-acetyl cysteine, a free-radical scavenger. The transgenic silkworm was made transparent by feeding a diet containing chemicals that inhibit uric acid deposition in the epithelial cells. In the transparent silkworms, GFP fluorescence in the fat body could be observed from outside the body. Injection of salicylic acid or iron sulfate, tissue-injuring chemicals, into the transparent silkworms decreased the fluorescence intensity of the GFP in the fat body. These findings suggest that the transparent GFP-expressing silkworm model is useful for evaluating the toxicity of chemicals that induce tissue injury.
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Affiliation(s)
- Yoshinori Inagaki
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 111-0033, Japan
| | - Yasuhiko Matsumoto
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 111-0033, Japan
| | - Masaki Ishii
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 111-0033, Japan
| | - Keiro Uchino
- Transgenic Silkworm Research Unit, National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634 Japan
| | - Hideki Sezutsu
- Transgenic Silkworm Research Unit, National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634 Japan
| | - Kazuhisa Sekimizu
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 111-0033, Japan
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166
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Uchida R, Hanaki H, Matsui H, Hamamoto H, Sekimizu K, Iwatsuki M, Kim YP, Tomoda H. In vitro and in vivo anti-MRSA activities of nosokomycins. Drug Discov Ther 2015; 8:249-54. [PMID: 25639304 DOI: 10.5582/ddt.2014.01050] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of nosokomycins A to D discovered in the silkworm-MRSA infection screening was investigated. The minimum inhibitory concentration (MIC) values of nosokomycins for authentic MRSA and S. aureus strains were calculated to be 0.06 to 2.0 μg/mL. They also showed potent inhibitory activity against 54 clinically isolated MRSA strains. Furthermore, nosokomycin A proved effective in the mouse-MRSA infection model.
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Affiliation(s)
- Ryuji Uchida
- Graduate School of Pharmaceutical Sciences, Kitasato University
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167
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A novel mutation in the vraS gene of Staphylococcus aureus contributes to reduce susceptibility against daptomycin. J Antibiot (Tokyo) 2015; 68:646-8. [PMID: 25899124 DOI: 10.1038/ja.2015.42] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/09/2015] [Accepted: 03/25/2015] [Indexed: 11/09/2022]
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168
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Ishii K, Hamamoto H, Sekimizu K. Studies of host-pathogen interactions and immune-related drug development using the silkworm: interdisciplinary immunology, microbiology, and pharmacology studies. Drug Discov Ther 2015; 9:238-46. [PMID: 25865526 DOI: 10.5582/ddt.2015.01015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Innate immunity acts as a front-line barrier against invading pathogens, and the majority of the components are widely conserved among species. Regulation of innate immunity is important for overcoming infections and preventing self-damaging sepsis. Using the silkworm (Bombyx mori) as an animal model, we elucidated the activation processes of innate immunity with emphasis on a multifunctional insect cytokine called paralytic peptide. Moreover, we established an ex vivo system using silkworm larval specimens to quantitatively evaluate the immunostimulatory activity of natural compounds. We observed that overactivation of innate immunity in silkworms induces tissue damage followed by host death, resembling sepsis-induced multi-organ failure in humans. Here, we summarize our recent findings and propose the usefulness of the silkworm as an animal model for studying immune regulation and for evaluating compounds with the potential to regulate innate immunity.
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Affiliation(s)
- Kenichi Ishii
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo
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