排序方式: 共有12条查询结果,搜索用时 15 毫秒
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Dr. Keishi Ishida Dr. Gulimila Shabuer Dr. Sebastian Schieferdecker Dr. Sacha J. Pidot Prof. Dr. Timothy P. Stinear Uwe Knuepfer Michael Cyrulies Prof. Dr. Christian Hertweck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(58):13147-13151
Anaerobic bacteria have only recently been recognized as a source of antibiotics; yet, the metabolic potential of Negativicutes (Gram-negative staining Firmicutes) such as the oak-associated Dendrosporobacter quercicolus has remained unknown. Genome mining of D. quercicolus and phylogenetic analyses revealed a gene cluster for a type II polyketide synthase (PKS) complex that belongs to the most ancestral enzyme systems of this type. Metabolic profiling, NMR analyses, and stable-isotope labeling led to the discovery of a new family of anthraquinone-type polyphenols, the dendrubins, which are diversified by acylation, methylation, and dimerization. Dendrubin A and B were identified as strong antibiotics against a range of clinically relevant, human-pathogenic mycobacteria. 相似文献
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Bioorthogonal Chemical Reporters for Selective In Situ Probing of Mycomembrane Components in Mycobacteria
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Hannah N. Foley Jessica A. Stewart Dr. Herbert W. Kavunja Sarah R. Rundell Prof. Dr. Benjamin M. Swarts 《Angewandte Chemie (International ed. in English)》2016,55(6):2053-2057
The global pathogen Mycobacterium tuberculosis and other species in the suborder Corynebacterineae possess a distinctive outer membrane called the mycomembrane (MM). The MM is composed of mycolic acids, which are either covalently linked to an underlying arabinogalactan layer or incorporated into trehalose glycolipids that associate with the MM non‐covalently. These structures are generated through a process called mycolylation, which is central to mycobacterial physiology and pathogenesis and is an important target for tuberculosis drug development. Current approaches to investigating mycolylation rely on arduous analytical methods that occur outside the context of a whole cell. Herein, we describe mycobacteria‐specific chemical reporters that can selectively probe either covalent arabinogalactan mycolates or non‐covalent trehalose mycolates in live mycobacteria. These probes, in conjunction with bioorthogonal chemistry, enable selective in situ detection of the major MM components. 相似文献
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裂解甲基化气相色谱法区别不产色分支杆菌菌群的研究 总被引:1,自引:0,他引:1
应用新的气相色谱技术──裂解甲基化法解析了不产色分支杆菌菌群的细胞脂类组分,结果表明,这个方法能对该群7种细菌进行特异性区分。其特点是在高温裂解的瞬间完成酯化反应,长链大分子的支菌酸(50~80个碳原子)断裂成脂肪酸碎片C_(24:0)和C_(26:0)流出。裂解甲基化法分析快捷,谱图重现性好,具有推广应用的价值。 相似文献
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Marco Beccaria Flavio A. Franchina Mavra Nasir Theodore Mellors Jane E. Hill Giorgia Purcaro 《Molecules (Basel, Switzerland)》2021,26(15)
Species of Mycobacteriaceae cause disease in animals and humans, including tuberculosis and leprosy. Individuals infected with organisms in the Mycobacterium tuberculosis complex (MTBC) or non-tuberculous mycobacteria (NTM) may present identical symptoms, however the treatment for each can be different. Although the NTM infection is considered less vital due to the chronicity of the disease and the infrequency of occurrence in healthy populations, diagnosis and differentiation among Mycobacterium species currently require culture isolation, which can take several weeks. The use of volatile organic compounds (VOCs) is a promising approach for species identification and in recent years has shown promise for use in the rapid analysis of both in vitro cultures as well as ex vivo diagnosis using breath or sputum. The aim of this contribution is to analyze VOCs in the culture headspace of seven different species of mycobacteria and to define the volatilome profiles that are discriminant for each species. For the pre-concentration of VOCs, solid-phase micro-extraction (SPME) was employed and samples were subsequently analyzed using gas chromatography–quadrupole mass spectrometry (GC-qMS). A machine learning approach was applied for the selection of the 13 discriminatory features, which might represent clinically translatable bacterial biomarkers. 相似文献
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Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The identification of mycobacteria in tissue sections can be made through a microscopic examination with fite-faraco staining or PCR method. Paraffin blocks from four patients with leprosy were retrieved from The Pathologic Department of Dr.Soetomo Hospital, Surabaya. Two cases were from paucibacillary leprosy patients with no mycobacteria stained by fite-faraco. PCR assay showed a negative result. The other two cases were multibacillary leprosy with many bacteria stained by fite-faraco. PCR assay showed a positive result. 相似文献
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《Journal of mass spectrometry : JMS》2017,52(9):597-602
Conventional identification of mycobacteria species is slow, laborious and has low discriminatory power. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) has proved highly effective for identifying conventional bacteria, and it may also be useful for identifying mycobacteria. The aim of this study was to evaluate and compare MALDI‐TOF MS with currently recommended molecular methods for the identification of nontuberculous mycobacteria (NTM), applying Mycobacteria Libraries v3.0 (ML3.0) and v2.0 (ML2.0). A total of 240 clinical isolates of 41 NTM species grown on solid media were analysed: 132 isolates of slow‐growing mycobacteria and 108 of rapid‐growing mycobacteria. MALDI‐TOF MS, using ML3.0, identified 192 (80%) NTM isolates with a score ≥1.7, encompassing 35 (85.4%) different species, that is, 17 (7.1%; p = 0.0863) isolates and 15 (36.6%; p = 0.0339) species more than currently recommended molecular techniques (polymerase chain reaction reverse hybridization). All these isolates were correctly identified according to molecular identification methods. The application of ML3.0 also identified 15 (6.2%) NTM isolates more than ML2.0 (p < 0.01). The scores obtained with MALDI‐TOF MS using ML3.0 (mean score: 1.960) were higher in 147 (61.2%) isolates than when using ML2.0 (mean score: 1.797; p < 0.01). Three of the species analysed were not included in either database, so they were not recognized by this system. In conclusion, MALDI‐TOF MS identified more isolates and species than the recommended polymerase chain reaction reverse hybridization assays. Although the new ML3.0 is not the definitive database, it yielded better results than ML2.0. This shows that the updating of the MALDI‐TOF MS database plays an essential role in mycobacterial identification. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Isoniazid@Fe2O3 Nanocontainers and Their Antibacterial Effect on Tuberculosis Mycobacteria
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Dr. Peter Leidinger Jens Treptow Kristine Hagens Jacqueline Eich Dr. Nicole Zehethofer Dr. Dominik Schwudke Dr. Wulf Oehlmann Dr. Heinrich Lünsdorf Dr. Oliver Goldmann Prof. Dr. Ulrich E. Schaible Dr. Kurt E. J. Dittmar Prof. Dr. Claus Feldmann 《Angewandte Chemie (International ed. in English)》2015,54(43):12597-12601
Isoniazid‐filled Fe2O3 hollow nanospheres (INH@Fe2O3, diameter <30 nm, 48 wt % INH‐load) are prepared for the first time and suggested for tuberculosis therapy. After dextran‐functionalization, the INH@Fe2O3@DEX nanocontainers show strong activity against Mycobacterium tuberculosis (M.tb.) and M.tb.‐infected macrophages. The nanocontainers can be considered as “Trojan horses” and show efficient, active uptake into both M.tb.‐infected macrophages and even into mycobacterial cells. 相似文献
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Acute Modulation of Mycobacterial Cell Envelope Biogenesis by Front‐Line Tuberculosis Drugs
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Frances P. Rodriguez‐Rivera Xiaoxue Zhou Julie A. Theriot Carolyn R. Bertozzi 《Angewandte Chemie (International ed. in English)》2018,57(19):5267-5272
Front‐line tuberculosis (TB) drugs have been characterized extensively in vitro and in vivo with respect to gene expression and cell viability. However, little work has been devoted to understanding their effects on the physiology of the cell envelope, one of the main targets of this clinical regimen. Herein, we use metabolic labeling methods to visualize the effects of TB drugs on cell envelope dynamics in mycobacterial species. We developed a new fluorophore–trehalose conjugate to visualize trehalose monomycolates of the mycomembrane using super‐resolution microscopy. We also probed the relationship between mycomembrane and peptidoglycan dynamics using a dual metabolic labeling strategy. Finally, we found that metabolic labeling of both cell envelope structures reports on drug effects on cell physiology in two hours, far faster than a genetic sensor of cell envelope stress. Our work provides insight into acute drug effects on cell envelope biogenesis in live mycobacteria. 相似文献