101
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Jeong YC, Bikadi Z, Hazai E, Moloney MG. A Detailed Study of Antibacterial 3-Acyltetramic Acids and 3-Acylpiperidine-2,4-diones. ChemMedChem 2014; 9:1826-37. [DOI: 10.1002/cmdc.201402093] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Indexed: 12/12/2022]
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102
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Yu L, Trujillo ME, Miyanaga S, Saiki I, Igarashi Y. Campechic acids A and B: anti-invasive polyether polyketides from a soil-derived Streptomyces. JOURNAL OF NATURAL PRODUCTS 2014; 77:976-982. [PMID: 24592993 DOI: 10.1021/np401071x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Campechic acids A (1) and B (2), two new polyketides, were isolated from the culture extract of Streptomyces sp., and their structures were determined by NMR and MS spectroscopic analysis. Campechic acids are polyether-polyketides functionalized by two tetrahydrofuran rings, an enolized 1,3-diketone, and multiple methyl substitutions. Absolute configuration of nine stereogenic centers in 1, except for four chiral centers in the cyclic ether moieties, was determined by the 1H NMR anisotropy method in combination with chemical degradation. Campechic acids exhibited potent inhibitory effects on tumor cell invasion with IC50 values in the nanomolar to submicromolar range.
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Affiliation(s)
- Linkai Yu
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University , 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
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103
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Cerium oxide and iron oxide nanoparticles abolish the antibacterial activity of ciprofloxacin against gram positive and gram negative biofilm bacteria. Cytotechnology 2014; 67:427-35. [PMID: 24643389 DOI: 10.1007/s10616-014-9701-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 02/12/2014] [Indexed: 10/25/2022] Open
Abstract
Metal oxide nanoparticles have been suggested as good candidates for the development of antibacterial agents. Cerium oxide (CeO2) and iron oxide (Fe2O3) nanoparticles have been utilized in a number of biomedical applications. Here, the antibacterial activity of CeO2 and Fe2O3 nanoparticles were evaluated on a panel of gram positive and gram negative bacteria in both the planktonic and biofilm cultures. Additionally, the effect of combining CeO2 and Fe2O3 nanoparticles with the broad spectrum antibiotic ciprofloxacin on tested bacteria was investigated. Thus, minimum inhibitory concentrations (MICs) of CeO2 and Fe2O3 nanoparticles that are required to inhibit bacterial planktonic growth and bacterial biofilm, were evaluated, and were compared to the MICs of the broad spectrum antibiotic ciprofloxacin alone or in the presence of CeO2 and Fe2O3 nanoparticles. Results of this study show that both CeO2 and Fe2O3 nanoparticles fail to inhibit bacterial growth and biofilm biomass for all the bacterial strains tested. Moreover, adding CeO2 or Fe2O3 nanoparticles to the broad spectrum antibiotic ciprofloxacin almost abolished its antibacterial activity. Results of this study suggest that CeO2 and Fe2O3 nanoparticles are not good candidates as antibacterial agents, and they could interfere with the activity of important antibiotics.
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104
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Pharmacological properties of NAI-603, a well-tolerated semisynthetic derivative of ramoplanin. Antimicrob Agents Chemother 2014; 58:1922-9. [PMID: 24419352 DOI: 10.1128/aac.01620-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
NAI-603 is a ramoplanin derivative designed to overcome the tolerability issues of the parent drug as a systemic agent. NAI-603 is highly active against aerobic and anaerobic Gram-positive bacteria, with MICs ranging from 0.008 to 8 μg/ml. MICs were not significantly affected by pH (range, 6 to 8), by inoculum up to 10(8) CFU/ml, or by addition of 50% human serum. Against staphylococci and enterococci, NAI-603 was rapidly bactericidal, with minimum bactericidal concentration (MBC)/MIC ratios never exceeding 4. The frequency of spontaneous resistance was low at 2× to 4× MIC (≤1×10(-6) to ≤1×10(-8)) and below the detection limit (about ≤1×10(-9)) at 8×MIC. Serial subcultures at 0.5×MIC yielded at most an 8-fold increase in MICs. In a systemic infection induced by methicillin-resistant Staphylococcus aureus (MRSA), the 50% effective dose (ED50) of intravenous (i.v.) NAI-603 was 0.4 mg/kg, lower than that of oral (p.o.) linezolid (1.4 mg/kg) and subcutaneous (s.c.) teicoplanin (1.4 mg/kg) or vancomycin (0.6 mg/kg). In neutropenic mice infected with vancomycin-resistant enterococci (VRE), the ED50s for NAI-603 were 1.1 to 1.6 mg/kg i.v., compared to 0.5 mg/kg i.v. of ramoplanin. The bactericidal activity was confirmed in vivo in the rat granuloma pouch model induced by MRSA, where NAI-603, at 40 mg/kg i.v., induced about a 2- to 3-log10-reduction in viable bacteria in the exudates, which persisted for more than 72 h. The pharmacokinetic (PK) profiles of NAI-603 and ramoplanin at 20 mg/kg show similar half-lives (3.27 and 3.80 h, respectively) with the maximum concentration (Cmax) markedly higher for NAI-603 (207 μg/ml versus 79 μg/ml). The favorable pharmacological profile of NAI-603, coupled with the absence of local tolerability issues, supports further investigation.
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105
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Wu WJ, Zhang JW, Zhang WJ, Wei SP. A New Dihydrooxazole Antibiotic from the Fermentation Broth of Streptomyces djakartensis. HETEROCYCLES 2014. [DOI: 10.3987/com-14-13001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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106
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Asencio G, Lavin P, Alegría K, Domínguez M, Bello H, González-Rocha G, González-Aravena M. Antibacterial activity of the Antarctic bacterium Janthinobacterium sp. SMN 33.6 against multi-resistant Gram-negative bacteria. ELECTRON J BIOTECHN 2014. [DOI: 10.1016/j.ejbt.2013.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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107
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Dutta D, Mishra S. The structural and energetic aspects of substrate binding and the mechanism of action of the DapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) investigated using a hybrid QM/MM method. Phys Chem Chem Phys 2014; 16:26348-58. [DOI: 10.1039/c4cp03986f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Substrate binding and the mechanism of action of the DapE-encodedN-succinyl-l,l-diaminopimelic acid desuccinylase (DapE).
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Affiliation(s)
- Debodyuti Dutta
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur, India
| | - Sabyashachi Mishra
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur, India
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108
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109
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Maffioli SI. A Chemist's Survey of Different Antibiotic Classes. Antibiotics (Basel) 2013. [DOI: 10.1002/9783527659685.ch1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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110
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Jeong YC, Moloney MG. Synthesis and antibacterial activity of monocyclic 3-carboxamide tetramic acids. Beilstein J Org Chem 2013; 9:1899-906. [PMID: 24204399 PMCID: PMC3817595 DOI: 10.3762/bjoc.9.224] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 08/23/2013] [Indexed: 11/23/2022] Open
Abstract
A chemical library of carboxamide-substituted tetramates designed by analogy with antibacterial natural products, a method for their rapid construction, and the evaluation of their antibacterial activity is reported.
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Affiliation(s)
- Yong-Chul Jeong
- Chemistry Research Laboratory, University of Oxford, Mansfield Rd, University of Oxford, OX1 3TA, UK
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111
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Higginbotham SJ, Arnold AE, Ibañez A, Spadafora C, Coley PD, Kursar TA. Bioactivity of fungal endophytes as a function of endophyte taxonomy and the taxonomy and distribution of their host plants. PLoS One 2013; 8:e73192. [PMID: 24066037 PMCID: PMC3774686 DOI: 10.1371/journal.pone.0073192] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 07/18/2013] [Indexed: 11/21/2022] Open
Abstract
Fungal endophytes--fungi that grow within plant tissues without causing immediate signs of disease--are abundant and diverse producers of bioactive secondary metabolites. Endophytes associated with leaves of tropical plants are an especially exciting and relatively untapped source of novel compounds. However, one major challenge in drug discovery lies in developing strategies to efficiently recover highly bioactive strains. As part of a 15-year drug discovery project, foliar endophytes were isolated from 3198 plant samples (51 orders, 105 families and at least 232 genera of angiosperms and ferns) collected in nine geographically distinct regions of Panama. Extracts from culture supernatants of >2700 isolates were tested for bioactivity (in vitro percent inhibition of growth, % IG) against a human breast cancer cell line (MCF-7) and the causative agents of malaria, leishmaniasis, and Chagas' disease. Overall, 32.7% of endophyte isolates were highly active in at least one bioassay, including representatives of diverse fungal lineages, host lineages, and collection sites. Up to 17% of isolates tested per assay were highly active. Most bioactive strains were active in only one assay. Fungal lineages differed in the incidence and degree of bioactivity, as did fungi from particular plant taxa, and greater bioactivity was observed in endophytes isolated from plants in cloud forests vs. lowland forests. Our results suggest that using host taxonomy and forest type to tailor plant collections, and selecting endophytes from specific orders or families for cultivation, will markedly increase the efficiency and efficacy of discovering bioactive metabolites for particular pharmaceutical targets.
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Affiliation(s)
| | - A. Elizabeth Arnold
- School of Plant Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Alicia Ibañez
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Carmenza Spadafora
- Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Panama, Republic of Panama
| | - Phyllis D. Coley
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
- Department of Biology, University of Utah, Salt Lake City, Utah, United States of America
| | - Thomas A. Kursar
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
- Department of Biology, University of Utah, Salt Lake City, Utah, United States of America
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112
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Müller R, Wink J. Future potential for anti-infectives from bacteria - how to exploit biodiversity and genomic potential. Int J Med Microbiol 2013; 304:3-13. [PMID: 24119567 DOI: 10.1016/j.ijmm.2013.09.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The early stages of antibiotic development include the identification of novel hit compounds. Since actinomycetes and myxobacteria are still the most important natural sources of active metabolites, we provide an overview on these producers and discuss three of the most promising approaches toward finding novel anti-infectives from microorganisms. These are defined as the use of biodiversity to find novel producers, the variation of culture conditions and induction of silent genes, and the exploitation of the genomic potential of producers via "genome mining". Challenges that exist beyond compound discovery are outlined in the last section.
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Affiliation(s)
- Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), P.O. Box 151150, 66041 Saarbrücken, Germany; Helmholtz Centre for Infectious Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Joachim Wink
- Helmholtz Centre for Infectious Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany.
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113
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Wertheim H, Van Nguyen K, Hara GL, Gelband H, Laxminarayan R, Mouton J, Cars O. Global survey of polymyxin use: A call for international guidelines. J Glob Antimicrob Resist 2013; 1:131-134. [PMID: 24749079 PMCID: PMC3991322 DOI: 10.1016/j.jgar.2013.03.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Revised: 03/20/2013] [Accepted: 03/25/2013] [Indexed: 11/04/2022] Open
Abstract
Polymyxins (polymyxin B and colistin) are older bactericidal antibiotics that are increasingly used to treat infections caused by multidrug-resistant (MDR) Gram-negative bacteria. However, dosing and clinical use of these drugs vary widely. This survey was undertaken to reveal how polymyxins are used worldwide. Data were collected through a structured online questionnaire consisting of 24 questions regarding colistin usage patterns and indications as well as colistin dosage for adult patients. The questionnaire was disseminated in 2011 to relevant experts worldwide and was completed by 284 respondents from 56 different countries. Respondents from 11/56 countries (20%) had no access to colistin; 58/284 respondents (20.4%) reported that in 2010 they experienced that colistin was not available when needed. Formulations of polymyxins used were reported as: colistimethate sodium (48.6%); colistin sulfate (14.1%); both (1.4%); polymyxin B (1.4%); and unknown. Intravenous formulations were used by 84.2%, aerosolised or nebulised colistin by 44.4% and oral colistin for selective gut decontamination by 12.7%. Common indications for intravenous colistin were ventilator-associated pneumonia, sepsis and catheter-related infections with MDR Gram-negative bacteria. Only 21.2% of respondents used a colistin-loading dose, mainly in Europe and North America. This survey reveals that the majority of respondents use colistin and a few use polymyxin B. The survey results show that colistin is commonly underdosed. Clear guidance is needed on indications, dosing and antibiotic combinations to improve clinical outcomes and delay the emergence of resistance. Colistin should be considered a last-resort drug and its use should be controlled. International guidelines are urgently needed.
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Affiliation(s)
- Heiman Wertheim
- Wellcome Trust Major Overseas Program, Oxford University Clinical Research Unit, National Hospital for Tropical Diseases, Hanoi, Viet Nam ; Nuffield Department of Clinical Medicine, Centre for Tropical Diseases, Oxford, UK
| | | | - Gabriel Levy Hara
- Infectious Diseases Unit, Hospital Carlos G. Durand, Buenos Aires, Argentina
| | - Hellen Gelband
- Center for Disease Dynamics Economics and Policy, Washington, DC, USA
| | - Ramanan Laxminarayan
- Center for Disease Dynamics Economics and Policy, Washington, DC, USA ; Princeton University, Princeton, NJ, USA
| | - Johan Mouton
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Otto Cars
- Action on Antibiotic Resistance (ReAct), Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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114
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Capturing Linear Intermediates and C-Terminal Variants during Maturation of the Thiopeptide GE2270. ACTA ACUST UNITED AC 2013; 20:1067-77. [DOI: 10.1016/j.chembiol.2013.07.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/05/2013] [Accepted: 07/10/2013] [Indexed: 11/18/2022]
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115
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Verma D, Jacobs DJ, Livesay DR. Variations within class-A β-lactamase physiochemical properties reflect evolutionary and environmental patterns, but not antibiotic specificity. PLoS Comput Biol 2013; 9:e1003155. [PMID: 23874193 PMCID: PMC3715408 DOI: 10.1371/journal.pcbi.1003155] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 06/10/2013] [Indexed: 11/19/2022] Open
Abstract
The bacterial enzyme β-lactamase hydrolyzes the β-lactam ring of penicillin and chemically related antibiotics, rendering them ineffective. Due to rampant antibiotic overuse, the enzyme is evolving new resistance activities at an alarming rate. Related, the enzyme's global physiochemical properties exhibit various amounts of conservation and variability across the family. To that end, we characterize the extent of property conservation within twelve different class-A β-lactamases, and conclusively establish that the systematic variations therein parallel their evolutionary history. Large and systematic differences within electrostatic potential maps and pairwise residue-to-residue couplings are observed across the protein, which robustly reflect phylogenetic outgroups. Other properties are more conserved (such as residue pKa values, electrostatic networks, and backbone flexibility), yet they also have systematic variations that parallel the phylogeny in a statistically significant way. Similarly, the above properties also parallel the environmental condition of the bacteria they are from in a statistically significant way. However, it is interesting and surprising that the only one of the global properties (protein charge) parallels the functional specificity patterns; meaning antibiotic resistance activities are not significantly constraining the global physiochemical properties. Rather, extended spectrum activities can emerge from the background of nearly any set of electrostatic and dynamic properties.
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Affiliation(s)
- Deeptak Verma
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
| | - Donald J. Jacobs
- Department of Physics and Optical Science, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
| | - Dennis R. Livesay
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
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116
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Kurosu M, Siricilla S, Mitachi K. Advances in MRSA drug discovery: where are we and where do we need to be? Expert Opin Drug Discov 2013; 8:1095-116. [PMID: 23829425 DOI: 10.1517/17460441.2013.807246] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Methicillin-resistant Staphylococcus aureus (MRSA) have been on the increase during the past decade, due to the steady growth of the elderly and immunocompromised patients, and the emergence of multidrug-resistant (MDR) bacterial strains. Although there are a limited number of anti-MRSA drugs available, a number of different combination antimicrobial drug regimens have been used to treat serious MRSA infections. Thus, the addition of several new antistaphylococcal drugs into clinical practice should broaden clinician's therapeutic options. As MRSA is one of the most common and problematic bacteria associated with increasing antimicrobial resistance, continuous efforts for the discovery of lead compounds as well as development of alternative therapies and faster diagnostics are required. AREAS COVERED This article summarizes the FDA-approved drugs to treat MRSA infections, the drugs in clinical trials, and the drug leads for MRSA and related Gram-positive bacterial infections. In addition, the article discusses the mode of action of antistaphylococcal molecules and the resistant mechanisms of some molecules. EXPERT OPINION The number of pipeline drugs presently undergoing clinical trials is not particularly encouraging. There are limited and rather expensive therapeutic options for MRSA infections in the critically ill. Further research efforts are required for effective phage therapy on MRSA infections in clinical use, which seem to be attractive therapeutic options for the future.
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Affiliation(s)
- Michio Kurosu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee, 881 Madison Avenue, Memphis, TN 38163, USA.
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117
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A simple assay to screen antimicrobial compounds potentiating the activity of current antibiotics. BIOMED RESEARCH INTERNATIONAL 2013; 2013:927323. [PMID: 23865073 PMCID: PMC3705824 DOI: 10.1155/2013/927323] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 05/29/2013] [Accepted: 06/04/2013] [Indexed: 11/27/2022]
Abstract
Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotics.
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118
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Huczyński A. FT-IR, 1H, 13C NMR, ESI-MS and semiempirical investigation of the structures of Monensin phenyl urethane complexes with the sodium cation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 110:285-290. [PMID: 23578536 DOI: 10.1016/j.saa.2013.03.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 03/12/2013] [Accepted: 03/13/2013] [Indexed: 06/02/2023]
Abstract
In this paper three forms of phenyl urethane of Monensin i.e. its acid form (H-MU) and its 1:1 complex with NaClO4 (H-MU-Na) and its sodium salt (Na-MU) were obtained and their structures were studied by FT-IR, (1)H and (13)C NMR, ESI MS and PM5 methods. The FT-IR data of Na-MU complexes demonstrate that the C=O urethane group is not engaged in the complexation of the sodium cation. However spectroscopic studies of H-MU-Na complex show that the structure in which this C=O urethane groups participate in the complexation is also present, but it is in the minority. The PM5 semiempirical calculations allow visualisation of all structures and determination of the hydrogen bond parameters.
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Affiliation(s)
- Adam Huczyński
- Faculty of Chemistry, Department of Biochemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.
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119
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Abstract
The author discuss the up to date interpretation of the concept of antibiotics and antibiotic research, as well as the present role of various natural, semisynthetic and synthetic antibiotic compounds in various areas of the human therapy. The origin and the total number of all antibiotics and applied antibiotics in the practice, as well as the bioactive microbial metabolites (antibiotics) in other therapeutical, non-antibiotic fields (including agriculture) are also reviewed. The author discusses main problems, such as increasing (poly)resistance, virulence of pathogens and the non-scientific factors (such as a decline of research efforts and their sociological, economic, financial and regulatory reasons). A short summary of the history of Hungarian antibiotic research is also provided. The author briefly discusses the prospects in the future and the general advantages of the natural products over synthetic compounds. It is concluded that new approaches for the investigation of the unlimited possibilities of the living world are necessary. The discovery of new types or simply neglected (micro)organisms and their biosynthetic capabilities, the introduction of new biotechnological and genetic methods (genomics, metagenom, genome mining) are absolutely required in the future. Orv. Hetil., 2013, 154, 563–573.
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120
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Abstract
INTRODUCTION Natural products have long been instrumental for discovering antibiotics, but many pharmaceutical companies abandoned this field and new antibiotics declined. In contrast, microbial resistance to current antibiotics has approached critical levels. AREAS COVERED This article gives historical perspectives by providing background about present-day economic realities and medical needs for antibiotic research, whose pipeline is mostly focused toward older known agents and newer semi-synthetic derivatives. Future research trends and projected technological developments open many innovative opportunities to discover novel antibacterials and find ways to control pathogenic bacteria without conventional antibiotics that provoke resistance. EXPERT OPINION The successful registration of daptomycin, retapamulin and fidaxomicin indicate the re-emergence of natural products has already begun. Semi-synthetic derivatives from other under-explored classes are progressing. More effort is being put into approaches such as total synthesis, discovery of new structural scaffolds for synthesis, alterations of biosynthetic pathways, combinatorial biosynthesis, new screening targets and new resources from which to isolate natural products. A return to successful screening of actinomycetes depends on solving the rate-limiting dereplication obstacle. Long-term solutions need to come from greater exploration of the massive numbers of uncultured microbes. An ultimate solution to the antibiotic-promoted microbial resistance cycle may lie in finding ways to control bacteria by non-lethal means.
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121
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Antibacterial activity composition of the fermentation broth of Streptomyces djakartensis NW35. Molecules 2013; 18:2763-8. [PMID: 23455667 PMCID: PMC6270429 DOI: 10.3390/molecules18032763] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/20/2013] [Accepted: 02/21/2013] [Indexed: 11/16/2022] Open
Abstract
The new compound Z-4-2 was isolated from the fermentation broth of Streptomyces djakartensis NW35, together with the known compound N-acetyltryptamine (Z-9-2) by bioassay-guided fractionation. Its chemical structure was elucidated as (E)-2-methoxy-1,4 naphthoquinone-1-oxime (Z-4-2) mainly by NMR analyses and MS spectral data. Their antibacterial activities against bacteria were evaluated by the filter paper method. The results of indicated that these compounds possess significant antibacterial activities.
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122
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Jeong YC, Anwar M, Bikadi Z, Hazai E, Moloney MG. Natural product inspired antibacterial tetramic acid libraries with dual enzyme inhibition. Chem Sci 2013. [DOI: 10.1039/c2sc21713a] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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123
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Abstract
The synthesis of the bacterial peptidoglycan has been recognized for over 50 years as fertile ground for antibacterial discovery. Initially, empirical screening of natural products for inhibition of bacterial growth detected many chemical classes of antibiotics whose specific mechanisms of action were eventually dissected and defined. Of the nontoxic antibiotics discovered, most were found to be inhibitors of either protein synthesis or cell wall synthesis, which led to more directed screening for inhibitors of these pathways. Directed screening and design programs for cell wall inhibitors have been undertaken since the 1960s. In that time it has become clear that, while certain steps and intermediates have yielded selective inhibitors and are established targets, other potential targets have not yielded inhibitors whose antibacterial activity is proven to be solely due to that inhibition. Why has this search been so problematic? Are the established targets still worth pursuing? This review will attempt to answer these and other questions and evaluate the viability of targets related to peptidoglycan synthesis.
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Affiliation(s)
- Lynn L Silver
- LL Silver Consulting, LLC, Springfield, New Jersey 07081, USA.
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124
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Sajid I, Shaaban KA, Hasnain S. Purification and identification of bioactive angucyclinones from Streptomyces matensis BG5, isolated from the rhizosphere of Rosa indica L. Prep Biochem Biotechnol 2012; 43:22-32. [PMID: 23215652 DOI: 10.1080/10826068.2012.693897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A newly isolated strain Streptomyces sp. BG5 was investigated for the production of bioactive compounds. The strain exhibited broad-spectrum activity against an array of nine test organisms including gram-positive bacteria, gram-negative bacteria, and fungal and microalgal pathogens, along with a moderate cytotoxic response (28.9% mortality) in a microwell cytotoxicity assay against the brine shrimp Artimia salina. The morphological, physiological, and biochemical characterization of the Streptomyces sp. BG5 strongly suggested it to be a member of the genus Streptomyces. The nucleotide sequence of 16S rRNA gene (1433 pb) of the Streptomyces sp. BG5 (Gene bank accession number EU301836) exhibited high similarity (98%) with Streptomyces matensis. The large-scale fermentation of Streptomyces sp. BG5 and subsequent extraction, isolation, and purification of the crude extract afforded three pure compounds. The structures of these compounds were identified as ochromycinone (1a), emycin D (2), and 1-acetyl-β-carbolin (3), based on nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and by comparison with reference data from the literature.
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Affiliation(s)
- Imran Sajid
- Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus, Lahore, Pakistan.
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125
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Dosler S, Gerceker AA. In vitro activities of antimicrobial cationic peptides; melittin and nisin, alone or in combination with antibiotics against Gram-positive bacteria. J Chemother 2012; 24:137-43. [PMID: 22759757 DOI: 10.1179/1973947812y.0000000007] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The In vitro activities of two antimicrobial cationic peptides, melittin and nisin alone and in combination with frequently used antibiotics (daptomycin, vancomycin, linezolid, ampicillin, and erythromycin), were assessed against clinical isolates of methicillin-susceptible Staphylococcus aureus, methicillin-resistant S. aureus and Enterococcus faecalis. Using the broth microdilution method, minimum inhibitory concentration (MIC) ranges of melittin and nisin against all strains were 2-8 μg/ml and 2-32 μg/ml respectively. In combination studies performed with the microdilution checkerboard method using a fractional inhibitory concentration index of ≤ 0.5 as borderline, synergistic interactions occurred more frequently with nisin-ampicillin combination against MSSA and nisin-daptomycin combination against E. faecalis strains. The results of the time-killing curve analysis demonstrated that the concentration dependent rapid bactericidal activity of nisin, and that synergism or early synergism was detected in most strains when nisin or melittin was used in combination with antibiotics even at concentrations of 0.5 × MIC.
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Affiliation(s)
- Sibel Dosler
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Istanbul University, Turkey.
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126
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Végh A, Bencsik T, Molnár P, Böszörményi A, Lemberkovics É, Kovács K, Kocsis B, Horváth G. Composition and Antipseudomonal Effect of Essential Oils Isolated from Different Lavender Species. Nat Prod Commun 2012. [DOI: 10.1177/1934578x1200701039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The aims of our research include the phytochemical characterization of the essential oils extracted from different lavender species ( Lavandula vera L., L. intermedia L., L. pyrenaica DC., and L. stoechas subsp. stoechas) that are important from therapeutic and economic aspects, as well as the optimization of the tube dilution method for microbiological investigation of the effect of essential oils on the selected Pseudomonas strain. The chemical and percentage compositions of the essential oils were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The main component of the essential oils in the majority of lavender species was linalool, while L-fencone was identified in the largest amount in L. stoechas subsp. stoechas. Tube dilution is one of the most frequently used methods for microbiological investigation. Its advantages are that it is easy to perform and provides information about minimum bactericidal concentration (MBC). Because of the lipophilic character of essential oils, the tube dilution method should be optimized for the detection of antibacterial activity of these plant extracts, and, therefore, emulsions containing 0.2% polysorbate 80 were prepared from the samples. In each of the eight investigated essential oils an inhibitory effect was detected, and MBC values were in the range 12.5-50 μL/mL in seven cases.
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Affiliation(s)
- Anna Végh
- Institute of Pharmaceutics and Central Clinical Pharmacy, Medical School, University of Pécs, 7624 Pécs, Honvéd u. 3., Hungary
| | - Tímea Bencsik
- Institute of Pharmacognosy, Medical School, University of Pécs, 7624 Pécs, Rókus u. 2., Hungary
| | - Péter Molnár
- Institute of Pharmacognosy, Medical School, University of Pécs, 7624 Pécs, Rókus u. 2., Hungary
| | - Andrea Böszörményi
- Institute of Pharmacognosy, Faculty of Pharmacy, Semmelweis University, 1085 Budapest, Üllői út 23, Hungary
| | - Éva Lemberkovics
- Institute of Pharmacognosy, Faculty of Pharmacy, Semmelweis University, 1085 Budapest, Üllői út 23, Hungary
| | - Krisztina Kovács
- Institute of Medical Microbiology and Immunology, Medical School, University of Pécs, 7624 Pécs, Szigeti út 12., Hungary
| | - Béla Kocsis
- Institute of Medical Microbiology and Immunology, Medical School, University of Pécs, 7624 Pécs, Szigeti út 12., Hungary
| | - Györgyi Horváth
- Institute of Pharmacognosy, Medical School, University of Pécs, 7624 Pécs, Rókus u. 2., Hungary
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127
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Anaerobic bacteria as producers of antibiotics. Appl Microbiol Biotechnol 2012; 96:61-7. [PMID: 22854892 DOI: 10.1007/s00253-012-4285-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 07/04/2012] [Accepted: 07/04/2012] [Indexed: 01/09/2023]
Abstract
Anaerobic bacteria are the oldest terrestrial creatures. They occur ubiquitously in soil and in the intestine of higher organisms and play a major role in human health, ecology, and industry. However, until lately no antibiotic or any other secondary metabolite has been known from anaerobes. Mining the genome sequences of Clostridium spp. has revealed a high prevalence of putative biosynthesis genes (PKS and NRPS), and only recently the first antibiotic from the anaerobic world, closthioamide, has been isolated from the cellulose degrading bacterium Clostridium cellulolyticum. The successful genetic induction of antibiotic biosynthesis in an anaerobe encourages further investigations of obligate anaerobes to tap their hidden biosynthetic potential.
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128
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Antibacterial, antifungal and antileishmanial activities of indolone-N-oxide derivatives. J Antibiot (Tokyo) 2012; 65:499-504. [PMID: 22828966 DOI: 10.1038/ja.2012.60] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An alarming increase in microbial resistance to traditional drugs and classical pharmacophores has spurred the search for new antimicrobial compounds. Indolone-N-oxides (INODs) possess a redox pharmacophore with promising, recently established, antimalarial activities. In this study, the anti-infectious properties of a series of INODs were investigated. The antibacterial activity was evaluated against five bacterial strains Gram-positive (Staphylococcus aureus, Enterococcus hirae), Gram-negative (Pseudomonas aeruginosa, Escherichia coli) and acid-fast (Mycobacterium tuberculosis). The antifungal activity was assessed using two fungal strains (Aspergillus niger, Candida albicans). The antileishmanial activity was tested against two leishmanial strains, axenically-cultured amastigote (Leishmania infantum, Leishmania amazonensis). The pharmacological activities are discussed as a function of structural and lipophilic characteristics. The Gram-positive bacterial strain E. hirae was found to be the most sensitive strain, whereas the Gram-negative E. coli was resistant to this family of compounds. One compound (64) was more potent than nalidixic acid against E. hirae, whereas another one (52) was equipotent as clotrimazole against C. albicans. INODs were microbe -cidal rather than -static. INODs showed good antitubercular activity in the low micromolar range (similar to ciprofloxacin). In addition, INOD-antiprotozoal potencies were confirmed against the leishmania parasite. INODs showed a broad spectrum of antimicrobial activity and offer a promising anti-infectious prototype worthy of being developed.
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129
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Brandi L, Maffioli S, Donadio S, Quaglia F, Sette M, Milón P, Gualerzi CO, Fabbretti A. Structural and functional characterization of the bacterial translocation inhibitor GE82832. FEBS Lett 2012; 586:3373-8. [PMID: 22841550 DOI: 10.1016/j.febslet.2012.07.040] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/10/2012] [Accepted: 07/11/2012] [Indexed: 10/28/2022]
Abstract
The structure of GE82832, a translocation inhibitor produced by a soil microorganism, is shown to be highly related to that of dityromycin, a bicyclodecadepsipeptide antibiotic discovered long ago whose characterization had never been pursued beyond its structural elucidation. GE82832 and dityromycin were shown to interfere with both aminoacyl-tRNA and mRNA movement and with the Pi release occurring after ribosome- and EF-G-dependent GTP hydrolysis. These findings and the unusual ribosomal localization of GE82832/dityromycin near protein S13 suggest that the mechanism of inhibition entails an interference with the rotation of the 30S subunit "head" which accompanies the ribosome-unlocking step of translocation.
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Affiliation(s)
- Letizia Brandi
- Department of Biosciences & Biotechnology, University of Camerino, Camerino (MC), Italy
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130
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Knerr P, van der Donk WA. Chemical synthesis and biological activity of analogues of the lantibiotic epilancin 15X. J Am Chem Soc 2012; 134:7648-51. [PMID: 22524291 PMCID: PMC3349288 DOI: 10.1021/ja302435y] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Indexed: 01/30/2023]
Abstract
Lantibiotics are a large family of antibacterial peptide natural products containing multiple post-translational modifications, including the thioether structures lanthionine and methyllanthionine. Efforts to probe structure-activity relationships and engineer improved pharmacological properties have driven the development of new methods to produce non-natural analogues of these compounds. In this study, solid-supported chemical synthesis was used to produce analogues of the potent lantibiotic epilancin 15X, in order to assess the importance of several N-terminal post-translational modifications for biological activity. Surprisingly, substitution of these moieties, including the unusual N-terminal D-lactyl moiety, resulted in relatively small changes in the antimicrobial activity and pore-forming ability of the peptides.
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Affiliation(s)
- Patrick
J. Knerr
- Howard Hughes Medical
Institute and Roger Adams Laboratory,
Department of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Wilfred A. van der Donk
- Howard Hughes Medical
Institute and Roger Adams Laboratory,
Department of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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131
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Ge Y, Wu J, Xia Y, Yang M, Xiao J, Yu J. Molecular dynamics simulation of the complex PBP-2x with drug cefuroxime to explore the drug resistance mechanism of Streptococcus suis R61. PLoS One 2012; 7:e35941. [PMID: 22563422 PMCID: PMC3338546 DOI: 10.1371/journal.pone.0035941] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 03/26/2012] [Indexed: 11/30/2022] Open
Abstract
Drug resistance of Streptococcus suis strains is a worldwide problem for both humans and pigs. Previous studies have noted that penicillin-binding protein (PBPs) mutation is one important cause of β-lactam antibiotic resistance. In this study, we used the molecular dynamics (MD) method to study the interaction differences between cefuroxime (CES) and PBP2x within two newly sequenced Streptococcus suis: drug-sensitive strain A7, and drug-resistant strain R61. The MM-PBSA results proved that the drug bound much more tightly to PBP2x in A7 (PBP2x-A7) than to PBP2x in R61 (PBP2x-R61). This is consistent with the evidently different resistances of the two strains to cefuroxime. Hydrogen bond analysis indicated that PBP2x-A7 preferred to bind to cefuroxime rather than to PBP2x-R61. Three stable hydrogen bonds were formed by the drug and PBP2x-A7, while only one unstable bond existed between the drug and PBP2x-R61. Further, we found that the Gln569, Tyr594, and Gly596 residues were the key mutant residues contributing directly to the different binding by pair wise energy decomposition comparison. By investigating the binding mode of the drug, we found that mutant residues Ala320, Gln553, and Thr595 indirectly affected the final phenomenon by topological conformation alteration. Above all, our results revealed some details about the specific interaction between the two PBP2x proteins and the drug cefuroxime. To some degree, this explained the drug resistance mechanism of Streptococcus suis and as a result could be helpful for further drug design or improvement.
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Affiliation(s)
- Yan Ge
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jiayan Wu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Yingjie Xia
- State Key Laboratory of Genetic Resources and Revolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Ming Yang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Jingfa Xiao
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Jun Yu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
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132
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Lin YL, Chen YS, Hsu YM, Yao CH, Chang TJ. PROTEOMIC ANALYSIS AND ANTIBACTERIAL EFFECTS OF LITHOSPERMI RADIX AGAINST COMMON BACTERIA FROM HUMAN INFECTED WOUNDS. BIOMEDICAL ENGINEERING-APPLICATIONS BASIS COMMUNICATIONS 2012. [DOI: 10.4015/s1016237212002937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The prevention and treatment of infections of human wounds are an important issue. In this investigation five herbal plants were selected, and their antibacterial effects were elucidated. Of these five herbal plants, the morphological changes of the one with the strongest antibacterial effects were observed using a scanning electron microscope (SEM) and the differential expression of bacterial proteins treated with them was determined by two-dimensional gel electrophoresis (2D-GE). Two proteins of weakly expressed spots from the highest matching percentage of 2D-GE were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/TOF). The results indicated that the Lithospermi radix have the best minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The SEM examination reveals different bactericidal morphological changes and colony distributions obtained using Lithospermi radix. 2D-GE reveals that Staphylococcus aureus treated with Lithospermi radix has the highest matching percentage (90.93%). Then identification of two proteins that are weakly expressed in Staphylococcus aureus by MALDI-TOF/TOF reveals that they are Holliday junction ATP-dependent DNA helicase RuvB and D-alanine: D-alanine ligase (DDI). These results are noteworthy to suggest that Lithospermi radix may be used as an antibacterial medicine to treatment of human wound infection.
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Affiliation(s)
- Yu-Li Lin
- Division of Pediatric Surgery, Department of Surgery, Cheng Ching General Hospital, Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yueh-Sheng Chen
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Yua-Man Hsu
- Department of Biological Science & Technology, College of Life Sciences, China Medical University, Taichung, Taiwan
| | - Chun-Hsu Yao
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Tien-Jye Chang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
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133
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Sanchez J, Yague P, Manteca A. New Insights in Streptomyces Fermentations. FERMENTATION TECHNOLOGY 2012; 1. [PMID: 24143295 DOI: 10.4172/2167-7972.1000e105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jesus Sanchez
- Area of Microbiology, Department of Functional Biology and IUBA, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
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134
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Bérdy J. Thoughts and facts about antibiotics: where we are now and where we are heading. J Antibiot (Tokyo) 2012; 65:385-95. [PMID: 22511224 DOI: 10.1038/ja.2012.27] [Citation(s) in RCA: 520] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The declining trends in microbial metabolite and natural products research and the refocusing of this research area are discussed. Renewing natural products research requires inexhaustible natural resources, as well as new genetic techniques and microbial sources, including endophytic microbes. The numbers of known bioactive metabolites are summarized according to their microbiological origin, biological activities and chemical structures. Synthetic and natural product-based libraries are also compared. Importantly, the wide range of microbial metabolite bioactivities, future trends and the importance of prioritizing natural products over synthetic compounds are emphasized.
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135
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Wei S, Wu W, Ji Z. Synthesis and antibacterial activities of 1-alkyl-3-methacryloyl (acryloyl) of benzimidazolone (thione) derivatives. Int J Mol Sci 2012; 13:4819-4830. [PMID: 22606011 PMCID: PMC3344247 DOI: 10.3390/ijms13044819] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 03/24/2012] [Accepted: 04/06/2012] [Indexed: 11/25/2022] Open
Abstract
A series of (28) 1-alkyl-3-methacryloyl (acryloyl)-benzimidazolone (thione) deriv-atives were synthesized. The structures of the new derivatives were confirmed by 1H-NMR, 13C-NMR and ESI-MS spectral analysis. The antibacterial activities of these compounds against several strains of bacteria, such as Bacillus cereus, Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, were evaluated by methods of paper disc-diffusion and broth mciro-dilution. Methacryloyl derivatives displayed higher antibacterial activities against tested bacterial strains than those of acryloyl derivatives in in vitro tests. A structure-activity relationship (SAR) study revealed that the presences of the methacryloyl moieties is essential to the antibacterial activities of the compounds.
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Affiliation(s)
| | | | - Zhiqin Ji
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +86-029-87092191; Fax: +86-029-87093987
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136
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Three novel cyclic hexapeptides from Streptomyces alboflavus 313 and their antibacterial activity. Eur J Med Chem 2012; 50:296-303. [DOI: 10.1016/j.ejmech.2012.02.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 01/17/2012] [Accepted: 02/03/2012] [Indexed: 11/24/2022]
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137
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Abstract
Aided by genome-mining strategies, knowledge of the prevalence and diversity of ribosomally synthesized natural products (RNPs) is rapidly increasing. Among these are the lantipeptides, posttranslationally modified peptides containing characteristic thioether cross-links imperative for bioactivity and stability. Though this family was once thought to be a limited class of antimicrobial compounds produced by gram-positive bacteria, new insights have revealed a much larger diversity of activity, structure, biosynthetic machinery, and producing organisms than previously appreciated. Detailed investigation of the enzymes responsible for installing the posttranslational modifications has resulted in improved in vivo and in vitro engineering systems focusing on enhancement of the therapeutic potential of these compounds. Although dozens of new lantipeptides have been isolated in recent years, bioinformatic analyses indicate that many hundreds more await discovery owing to the widespread frequency of lantipeptide biosynthetic machinery in bacterial genomes.
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Affiliation(s)
- Patrick J Knerr
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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138
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Activation of the dormant secondary metabolite production by introducing gentamicin-resistance in a marine-derived Penicillium purpurogenum G59. Mar Drugs 2012; 10:559-582. [PMID: 22611354 PMCID: PMC3347015 DOI: 10.3390/md10030559] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 02/13/2012] [Accepted: 02/21/2012] [Indexed: 11/16/2022] Open
Abstract
A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous DMSO, a total of 181 mutants were obtained by single colony isolation. In contrast to the strain G59, the EtOAc extracts of nine mutant cultures showed inhibitory effects on K562 cells, indicating that the nine mutants had acquired capability to produce antitumor metabolites. This was evidenced by TLC and HPLC analysis of EtOAc extracts of G59 and the nine mutants. Further isolation and characterization demonstrated that four antitumor secondary metabolites, janthinone (1), fructigenine A (2), aspterric acid methyl ester (3) and citrinin (4), were newly produced by mutant 5-1-4 compared to the parent strain G59, and which were also not found in the secondary metabolites of other Penicillium purpurogenum strains. However, Compounds 1–4 inhibited the proliferation of K562 cells with inhibition rates of 34.6% (1), 60.8% (2), 31.7% (3) and 67.1% (4) at 100 μg/mL, respectively. The present study demonstrated the effectiveness of a simple, yet practical approach to activate the production of dormant fungal secondary metabolites by introducing acquired resistance to aminoglycoside antibiotics, which could be applied to the studies for eliciting dormant metabolic potential of fungi to obtain cryptic secondary metabolites.
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139
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Biodiscovery from rare actinomycetes: an eco-taxonomical perspective. Appl Microbiol Biotechnol 2012; 93:1843-52. [DOI: 10.1007/s00253-012-3898-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/07/2012] [Accepted: 01/09/2012] [Indexed: 11/25/2022]
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140
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Dosler S, Gerceker AA. In vitro activities of nisin alone or in combination with vancomycin and ciprofloxacin against methicillin-resistant and methicillin-susceptible Staphylococcus aureus strains. Chemotherapy 2012; 57:511-6. [PMID: 22302084 DOI: 10.1159/000335598] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 12/04/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND We investigated the in vitro activities of nisin alone or in combination with vancomycin and ciprofloxacin against methicillin-resistant (MRSA) and -susceptible Staphylococcus aureus (MSSA) strains. METHODS The minimum inhibitory concentrations were determined by microbroth dilution technique. Antibiotic combinations were assessed using the checkerboard technique. The time-kill curve method was used for determining the bactericidal activity of nisin alone and in combination. RESULTS For both MSSA and MRSA strains, the minimum inhibitory concentrations of nisin ranged between 4 and 16 mg/l. With a fractional inhibitory concentration of ≥0.5 as borderline, synergistic interactions were seen in three of five isolates with nisin-ciprofloxacin compared to two of five isolates with nisin-vancomycin combinations against both MSSA and MRSA. No antagonism was observed. The results of time-kill curve analysis demonstrated concentration-dependent rapid bactericidal activity of nisin and synergism almost in all strains when nisin was used in combination with ciprofloxacin, and early synergistic interactions in some of the strains when it was used in combination with vancomycin. CONCLUSION Nisin seems to be a good candidate for further investigations in the treatment of Gram-positive bacteria, alone or in combination with antibiotics.
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Affiliation(s)
- Sibel Dosler
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Istanbul University, Turkey.
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141
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Bode HB, Reimer D, Fuchs SW, Kirchner F, Dauth C, Kegler C, Lorenzen W, Brachmann AO, Grün P. Determination of the Absolute Configuration of Peptide Natural Products by Using Stable Isotope Labeling and Mass Spectrometry. Chemistry 2012; 18:2342-8. [DOI: 10.1002/chem.201103479] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Indexed: 11/08/2022]
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142
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Zhang QG, Buckling A. Phages limit the evolution of bacterial antibiotic resistance in experimental microcosms. Evol Appl 2012; 5:575-82. [PMID: 23028398 PMCID: PMC3461140 DOI: 10.1111/j.1752-4571.2011.00236.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 12/13/2011] [Indexed: 01/21/2023] Open
Abstract
The evolution of multi-antibiotic resistance in bacterial pathogens, often resulting from de novo mutations, is creating a public health crisis. Phages show promise for combating antibiotic-resistant bacteria, the efficacy of which, however, may also be limited by resistance evolution. Here, we suggest that phages may be used as supplements to antibiotics in treating initially sensitive bacteria to prevent resistance evolution, as phages are unaffected by most antibiotics and there should be little cross-resistance to antibiotics and phages. In vitro experiments using the bacterium Pseudomonas fluorescens, a lytic phage, and the antibiotic kanamycin supported this prediction: an antibiotic–phage combination dramatically decreased the chance of bacterial population survival that indicates resistance evolution, compared with antibiotic treatment alone, whereas the phage alone did not affect bacterial survival. This effect of the combined treatment in preventing resistance evolution was robust to immigration of bacteria from an untreated environment, but not to immigration from environment where the bacteria had coevolved with the phage. By contrast, an isogenic hypermutable strain constructed from the wild-type P. fluorescens evolved resistance to all treatments regardless of immigration, but typically suffered very large fitness costs. These results suggest that an antibiotic–phage combination may show promise as an antimicrobial strategy.
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Affiliation(s)
- Quan-Guo Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing Normal University Beijing, China
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143
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Molecular weight and pH aspects of the efficacy of oligochitosan against methicillin-resistant Staphylococcus aureus (MRSA). Carbohydr Polym 2012; 87:545-550. [DOI: 10.1016/j.carbpol.2011.08.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 08/08/2011] [Accepted: 08/08/2011] [Indexed: 11/21/2022]
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144
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Polyak SW, Abell AD, Wilce MCJ, Zhang L, Booker GW. Structure, function and selective inhibition of bacterial acetyl-coa carboxylase. Appl Microbiol Biotechnol 2011; 93:983-92. [PMID: 22183085 DOI: 10.1007/s00253-011-3796-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 11/21/2011] [Accepted: 11/24/2011] [Indexed: 11/24/2022]
Abstract
Acetyl-CoA carboxylase (ACC) catalyses the first committed step in fatty acid biosynthesis: a metabolic pathway required for several important biological processes including the synthesis and maintenance of cellular membranes. ACC employs a covalently attached biotin moiety to bind a carboxyl anion and then transfer it to acetyl-CoA, yielding malonyl-CoA. These activities occur at two different subsites: the biotin carboxylase (BC) and carboxyltransferase (CT). Structural biology, together with small molecule inhibitor studies, has provided new insights into the molecular mechanisms that govern ACC catalysis, specifically the BC and CT subunits. Here, we review these recent findings and highlight key differences between the bacterial and eukaryotic isozymes with a view to establish those features that provide an opportunity for selective inhibition. Especially important are examples of highly selective small molecule inhibitors capable of differentiating between ACCs from different phyla. The implications for early stage antibiotic discovery projects, stemming from these studies, are discussed.
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Affiliation(s)
- S W Polyak
- School of Molecular and Biomedical Science, University of Adelaide, North Tce, Adelaide, South Australia 5005, Australia.
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145
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Kirst HA. Recent derivatives from smaller classes of fermentation-derived antibacterials. Expert Opin Ther Pat 2011; 22:15-35. [DOI: 10.1517/13543776.2012.642370] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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146
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Ding N, Zhang Z, Zhang W, Chun Y, Wang P, Qi H, Wang S, Li Y. Synthesis and antibacterial evaluation of a series of oligorhamnoside derivatives. Carbohydr Res 2011; 346:2126-35. [DOI: 10.1016/j.carres.2011.07.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 07/29/2011] [Accepted: 07/31/2011] [Indexed: 10/17/2022]
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147
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Zaghian S, Shokri D, Emtiazi G. Co-production of a UV-stable bacteriocin-like inhibitory substance (BLIS) and indole-3-acetic acid hormone (IAA) and their optimization by Taguchi design in Bacillus pumilus. ANN MICROBIOL 2011. [DOI: 10.1007/s13213-011-0359-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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148
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Hu P, Yang M, Zhang A, Wu J, Chen B, Hua Y, Yu J, Chen H, Xiao J, Jin M. Comparative genomics study of multi-drug-resistance mechanisms in the antibiotic-resistant Streptococcus suis R61 strain. PLoS One 2011; 6:e24988. [PMID: 21966396 PMCID: PMC3180280 DOI: 10.1371/journal.pone.0024988] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 08/22/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Streptococcus suis infections are a serious problem for both humans and pigs worldwide. The emergence and increasing prevalence of antibiotic-resistant S. suis strains pose significant clinical and societal challenges. RESULTS In our study, we sequenced one multi-drug-resistant S. suis strain, R61, and one S. suis strain, A7, which is fully sensitive to all tested antibiotics. Comparative genomic analysis revealed that the R61 strain is phylogenetically distinct from other S. suis strains, and the genome of R61 exhibits extreme levels of evolutionary plasticity with high levels of gene gain and loss. Our results indicate that the multi-drug-resistant strain R61 has evolved three main categories of resistance. CONCLUSIONS Comparative genomic analysis of S. suis strains with diverse drug-resistant phenotypes provided evidence that horizontal gene transfer is an important evolutionary force in shaping the genome of multi-drug-resistant strain R61. In this study, we discovered novel and previously unexamined mutations that are strong candidates for conferring drug resistance. We believe that these mutations will provide crucial clues for designing new drugs against this pathogen. In addition, our work provides a clear demonstration that the use of drugs has driven the emergence of the multi-drug-resistant strain R61.
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Affiliation(s)
- Pan Hu
- Division of Animal Infectious Disease in the State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Ming Yang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
- Graduate University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Anding Zhang
- Division of Animal Infectious Disease in the State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Jiayan Wu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Bo Chen
- Division of Animal Infectious Disease in the State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Yafeng Hua
- Division of Animal Infectious Disease in the State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Jun Yu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Huanchun Chen
- Division of Animal Infectious Disease in the State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Jingfa Xiao
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
- * E-mail: (JX); (MJ)
| | - Meilin Jin
- Division of Animal Infectious Disease in the State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China
- * E-mail: (JX); (MJ)
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149
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Zotchev SB. Marine actinomycetes as an emerging resource for the drug development pipelines. J Biotechnol 2011; 158:168-75. [PMID: 21683100 DOI: 10.1016/j.jbiotec.2011.06.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 05/03/2011] [Accepted: 06/01/2011] [Indexed: 10/18/2022]
Abstract
Many representatives of the order Actinomycetales are prolific producers of thousands of biologically active secondary metabolites. Actinomycetes from terrestrial sources have been studied and screened since the 1950s, yielding many important anti-infective and anti-cancer drugs. However, frequent re-discovery of the same compounds in terrestrial actinomycetes have made them less attractive for screening programs in the recent years. At the same time, actinomycetes isolated from the marine environment currently receive considerable attention due to the structural diversity and unique biological activities of their secondary metabolites. This review highlights achievements and challenges in the isolation of marine actinomycetes, some examples of bioactive metabolites identified by conventional screening, and presents new developments in the field of genome mining and heterologous expression of biosynthetic gene clusters leading to the discovery of novel compounds.
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Affiliation(s)
- Sergey B Zotchev
- Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands Vei 6/8, 7491 Trondheim, Norway.
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150
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Gahtori P, Ghosh SK. Design, synthesis and SAR exploration of hybrid 4-chlorophenylthiazolyl-s-triazine as potential antimicrobial agents. J Enzyme Inhib Med Chem 2011; 27:281-93. [PMID: 21657948 DOI: 10.3109/14756366.2011.587418] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Prashant Gahtori
- Department of Pharmaceutical Sciences, Dibrugarh University,
Dibrugarh, Assam, India
| | - Surajit K. Ghosh
- Department of Pharmaceutical Sciences, Dibrugarh University,
Dibrugarh, Assam, India
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