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Open accessJournal ArticleDOI: 10.7150/THNO.56205

Drug repurposing for next-generation combination therapies against multidrug-resistant bacteria.

04 Mar 2021-Theranostics (Ivyspring International Publisher)-Vol. 11, Iss: 10, pp 4910-4928
Abstract: Antimicrobial resistance has been a global health challenge that threatens our ability to control and treat life-threatening bacterial infections. Despite ongoing efforts to identify new drugs or alternatives to antibiotics, no new classes of antibiotic or their alternatives have been clinically approved in the last three decades. A combination of antibiotics and non-antibiotic compounds that could inhibit bacterial resistance determinants or enhance antibiotic activity offers a sustainable and effective strategy to confront multidrug-resistant bacteria. In this review, we provide a brief overview of the co-evolution of antibiotic discovery and the development of bacterial resistance. We summarize drug-drug interactions and uncover the art of repurposing non-antibiotic drugs as potential antibiotic adjuvants, including discussing classification and mechanisms of action, as well as reporting novel screening platforms. A pathogen-by-pathogen approach is then proposed to highlight the critical value of drug repurposing and its therapeutic potential. Finally, general advantages, challenges and development trends of drug combination strategy are discussed.

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Topics: Repurposing (58%), Antibiotic resistance (52%)

6 results found

Open accessJournal ArticleDOI: 10.3390/IJMS22094595
Abstract: The development of drug-resistant microorganisms has become a critical issue for modern medicine and drug discovery and development with severe socio-economic and ecological implications. Since standard and conventional treatment options are generally inefficient, leading to infection persistence and spreading, novel strategies are fundamentally necessary in order to avoid serious global health problems. In this regard, both metal and metal oxide nanoparticles (NPs) demonstrated increased effectiveness as nanobiocides due to intrinsic antimicrobial properties and as nanocarriers for antimicrobial drugs. Among them, gold, silver, copper, zinc oxide, titanium oxide, magnesium oxide, and iron oxide NPs are the most preferred, owing to their proven antimicrobial mechanisms and bio/cytocompatibility. Furthermore, inorganic NPs can be incorporated or attached to organic/inorganic films, thus broadening their application within implant or catheter coatings and wound dressings. In this context, this paper aims to provide an up-to-date overview of the most recent studies investigating inorganic NPs and their integration into composite films designed for antimicrobial therapies.

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Topics: Modern medicine (51%)

7 Citations

Open accessJournal ArticleDOI: 10.3390/PHARMACEUTICS13050660
05 May 2021-Pharmaceutics
Abstract: Flavonoids are among the most abundant natural bioactive compounds produced by plants. Many different activities have been reported for these secondary metabolites against numerous cells and systems. One of the most interesting is certainly the antimicrobial, which is stimulated through various molecular mechanisms. In fact, flavonoids are effective both in directly damaging the envelope of Gram-negative and Gram-positive bacteria but also by acting toward specific molecular targets essential for the survival of these microorganisms. The purpose of this paper is to present an overview of the most interesting results obtained in the research focused on the study of the interactions between flavonoids and bacterial proteins. Despite the great structural heterogeneity of these plant metabolites, it is interesting to observe that many flavonoids affect the same cellular pathways. Furthermore, it is evident that some of these compounds interact with more than one target, producing multiple effects. Taken together, the reported data demonstrate the great potential of flavonoids in developing innovative systems, which can help address the increasingly serious problem of antibiotic resistance.

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1 Citations

Open accessJournal ArticleDOI: 10.3390/PH14090907
Ziwen Tong1, Tianqi Xu1, Tian Deng1, Jingru Shi1  +2 moreInstitutions (1)
Abstract: Recently, a novel efflux pump gene cluster called tmexCD1-toprJ1 and its variants have been identified, which undermine the antibacterial activity of tigecycline, one of the last remaining options effective against multidrug-resistant (MDR) Gram-negative bacteria. Herein, we report the potent synergistic effect of the non-steroidal anti-inflammatory drug benzydamine in combination with tigecycline at sub-inhibitory concentrations against various temxCD-toprJ-positive Gram-negative pathogens. The combination of benzydamine and tigecycline killed all drug-resistant pathogens during 24 h of incubation. In addition, the evolution of tigecycline resistance was significantly suppressed in the presence of benzydamine. Studies on the mechanisms of synergism showed that benzydamine disrupted the bacterial proton motive force and the functionality of this kind of novel plasmid-encoded resistance-nodulation-division efflux pump, thereby promoting the intracellular accumulation of tigecycline. Most importantly, the combination therapy of benzydamine and tigecycline effectively improved the survival of Galleria mellonella larvae compared to tigecycline monotherapy. Our findings provide a promising drug combination therapeutic strategy for combating superbugs carrying the tmexCD-toprJ gene.

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Topics: Benzydamine (58%), Tigecycline (55%)

Open accessJournal ArticleDOI: 10.3390/PHARMACEUTICS13060819
Yi-Hsien Shih1, Donald Liu1, Yen-Chou Chen1, Ming-Hsuan Liao1  +2 moreInstitutions (1)
31 May 2021-Pharmaceutics
Abstract: Biofilms of Cutibacterium (C.) acnes (formerly Propionibacterium acnes) are responsible for the persistence and antibiotic resistance of acne vulgaris. In addition to the standard treatments for acne vulgaris, a common adjunctive treatment is the topical administration of nicotinamide (NAM). However, the effects of NAM on biofilms of C. acnes have never been explored. This study comprehensively investigates the effects of NAM against biofilms of C. acnes using in vitro and in vivo approaches. The results showed that NAM potentiated the efficacy of suboptimal dosing of tetracycline against C. acnes. Moreover, NAM alone decreased the formation and increased the degradation of biofilms in C. acnes. The antibiofilm effect of NAM against C. acnes was further enhanced in combination with deoxyribonuclease (DNase) I, an enzyme with known antibiofilm properties. The computational molecular docking, surface plasmon resonance analysis, and enzymatic kinetic assay demonstrated that NAM binds to DNase I and accelerated its reaction. In conclusion, NAM activates DNase I to attenuate biofilms of C. acnes. This offers valuable insights into the strategies against biofilms that are worth elaborating on in other biofilm-related chronic cutaneous infections in the future.

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Journal ArticleDOI: 10.1016/J.MOLSTRUC.2021.131551
Abstract: A series of 6-methylpyrimidin-4(3H)-one and oxo-1,2,4-triazolo[4,3-a]pyrimidine derivatives (1-18) was designed to meet the urgent need for novel antibacterial and antioxidant agents. The in vitro antibacterial activity revealed that most of the compounds exhibited a good inhibitory effect on Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria with MIC values in the range of 55–200 µg/mL for E. coli and 125–700 µg/mL for S. aureus. (E)-2-(2-(4-methoxybenzylidene)hydrazinyl)-6-methylpyrimidin-4(3H)-one (8) was the most active compound (MIC = 55 and 125 µg/mL against E. coli and S. aureus, respectively). All compounds exhibited antioxidant activity ranged from weak to moderate and high. The obtained findings revealed that compounds 3, 5, 6, 9, 16, and 18 have superiority among all compounds, demonstrating the highest capacity to deplete DPPH (1,1-diphenyl-2-picrylhydrazyl), compared to α-tocopherol, as a standard antioxidant agent. Surprisingly, compound 3 (2-hydrazinyl-6-methylpyrimidin-4(3H)-one) showed significantly higher antioxidant activity (EC50 = 2.12 µg/mL) than α-tocopherol (EC50 = 9.16 µg/mL). Molecular docking, drug-likeness data, physicochemical properties, and ADMET parameters of the compounds were in silico computed. The derivatives presented good properties for Lipinski’s parameters, poor solubility in the aqueous medium (Log S of -1.27 to -5.45), and PSA ≤140, indicating good permeability in biological membranes and gastrointestinal absorption. Molecular docking to the active sites of penicillin-binding protein and NADPH oxidase revealed that most compounds displayed minimal binding energy and have a good affinity toward the active pocket.

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Topics: Antibacterial activity (52%), DPPH (51%)


164 results found

Journal ArticleDOI: 10.1016/S1473-3099(15)00424-7
Yiyun Liu1, Yang Wang2, Timothy R. Walsh3, Ling-Xian Yi1  +16 moreInstitutions (7)
Abstract: Summary Background Until now, polymyxin resistance has involved chromosomal mutations but has never been reported via horizontal gene transfer. During a routine surveillance project on antimicrobial resistance in commensal Escherichia coli from food animals in China, a major increase of colistin resistance was observed. When an E coli strain, SHP45, possessing colistin resistance that could be transferred to another strain, was isolated from a pig, we conducted further analysis of possible plasmid-mediated polymyxin resistance. Herein, we report the emergence of the first plasmid-mediated polymyxin resistance mechanism, MCR-1, in Enterobacteriaceae. Methods The mcr-1 gene in E coli strain SHP45 was identified by whole plasmid sequencing and subcloning. MCR-1 mechanistic studies were done with sequence comparisons, homology modelling, and electrospray ionisation mass spectrometry. The prevalence of mcr-1 was investigated in E coli and Klebsiella pneumoniae strains collected from five provinces between April, 2011, and November, 2014. The ability of MCR-1 to confer polymyxin resistance in vivo was examined in a murine thigh model. Findings Polymyxin resistance was shown to be singularly due to the plasmid-mediated mcr-1 gene. The plasmid carrying mcr-1 was mobilised to an E coli recipient at a frequency of 10 −1 to 10 −3 cells per recipient cell by conjugation, and maintained in K pneumoniae and Pseudomonas aeruginosa . In an in-vivo model, production of MCR-1 negated the efficacy of colistin. MCR-1 is a member of the phosphoethanolamine transferase enzyme family, with expression in E coli resulting in the addition of phosphoethanolamine to lipid A. We observed mcr-1 carriage in E coli isolates collected from 78 (15%) of 523 samples of raw meat and 166 (21%) of 804 animals during 2011–14, and 16 (1%) of 1322 samples from inpatients with infection. Interpretation The emergence of MCR-1 heralds the breach of the last group of antibiotics, polymyxins, by plasmid-mediated resistance. Although currently confined to China, MCR-1 is likely to emulate other global resistance mechanisms such as NDM-1. Our findings emphasise the urgent need for coordinated global action in the fight against pan-drug-resistant Gram-negative bacteria. Funding Ministry of Science and Technology of China, National Natural Science Foundation of China.

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Topics: MCR-1 (65%), Colistin (61%), Plasmid-mediated resistance (58%) ... read more

2,827 Citations

Open accessJournal ArticleDOI: 10.1016/S1473-3099(13)70318-9
Abstract: The causes of antibiotic resistance are complex and include human behaviour at many levels of society; the consequences affect everybody in the world. Similarities with climate change are evident. Many efforts have been made to describe the many different facets of antibiotic resistance and the interventions needed to meet the challenge. However, coordinated action is largely absent, especially at the political level, both nationally and internationally. Antibiotics paved the way for unprecedented medical and societal developments, and are today indispensible in all health systems. Achievements in modern medicine, such as major surgery, organ transplantation, treatment of preterm babies, and cancer chemotherapy, which we today take for granted, would not be possible without access to effective treatment for bacterial infections. Within just a few years, we might be faced with dire setbacks, medically, socially, and economically, unless real and unprecedented global coordinated actions are immediately taken. Here, we describe the global situation of antibiotic resistance, its major causes and consequences, and identify key areas in which action is urgently needed.

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Topics: Antibiotic misuse (55%), Modern medicine (52%)

2,561 Citations

Open accessJournal ArticleDOI: 10.1016/S1473-3099(10)70143-2
Karthikeyan Kumarasamy1, Mark Toleman2, Timothy R. Walsh2, Jay Bagaria3  +27 moreInstitutions (11)
Abstract: Summary Background Gram-negative Enterobacteriaceae with resistance to carbapenem conferred by New Delhi metallo-β-lactamase 1 (NDM-1) are potentially a major global health problem. We investigated the prevalence of NDM-1, in multidrug-resistant Enterobacteriaceae in India, Pakistan, and the UK. Methods Enterobacteriaceae isolates were studied from two major centres in India—Chennai (south India), Haryana (north India)—and those referred to the UK's national reference laboratory. Antibiotic susceptibilities were assessed, and the presence of the carbapenem resistance gene bla NDM-1 was established by PCR. Isolates were typed by pulsed-field gel electrophoresis of XbaI-restricted genomic DNA. Plasmids were analysed by S1 nuclease digestion and PCR typing. Case data for UK patients were reviewed for evidence of travel and recent admission to hospitals in India or Pakistan. Findings We identified 44 isolates with NDM-1 in Chennai, 26 in Haryana, 37 in the UK, and 73 in other sites in India and Pakistan. NDM-1 was mostly found among Escherichia coli (36) and Klebsiella pneumoniae (111), which were highly resistant to all antibiotics except to tigecycline and colistin. K pneumoniae isolates from Haryana were clonal but NDM-1 producers from the UK and Chennai were clonally diverse. Most isolates carried the NDM-1 gene on plasmids: those from UK and Chennai were readily transferable whereas those from Haryana were not conjugative. Many of the UK NDM-1 positive patients had travelled to India or Pakistan within the past year, or had links with these countries. Interpretation The potential of NDM-1 to be a worldwide public health problem is great, and co-ordinated international surveillance is needed. Funding European Union, Wellcome Trust, and Wyeth.

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2,469 Citations

Journal ArticleDOI: 10.1038/NRMICRO3380
Jessica M A Blair1, Mark A. Webber1, Alison J. Baylay1, DO Ogbolu1  +1 moreInstitutions (1)
Abstract: Antibiotic-resistant bacteria that are difficult or impossible to treat are becoming increasingly common and are causing a global health crisis. Antibiotic resistance is encoded by several genes, many of which can transfer between bacteria. New resistance mechanisms are constantly being described, and new genes and vectors of transmission are identified on a regular basis. This article reviews recent advances in our understanding of the mechanisms by which bacteria are either intrinsically resistant or acquire resistance to antibiotics, including the prevention of access to drug targets, changes in the structure and protection of antibiotic targets and the direct modification or inactivation of antibiotics.

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Topics: Antibiotic resistance (56%), Drug resistance (51%)

2,096 Citations

Journal ArticleDOI: 10.1038/NATURE10388
22 Sep 2011-Nature
Abstract: The discovery of antibiotics more than 70 years ago initiated a period of drug innovation and implementation in human and animal health and agriculture. These discoveries were tempered in all cases by the emergence of resistant microbes. This history has been interpreted to mean that antibiotic resistance in pathogenic bacteria is a modern phenomenon; this view is reinforced by the fact that collections of microbes that predate the antibiotic era are highly susceptible to antibiotics. Here we report targeted metagenomic analyses of rigorously authenticated ancient DNA from 30,000-year-old Beringian permafrost sediments and the identification of a highly diverse collection of genes encoding resistance to β-lactam, tetracycline and glycopeptide antibiotics. Structure and function studies on the complete vancomycin resistance element VanA confirmed its similarity to modern variants. These results show conclusively that antibiotic resistance is a natural phenomenon that predates the modern selective pressure of clinical antibiotic use.

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Topics: Antibiotic resistance (58%), Resistome (55%)

1,593 Citations

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