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Duffey M, Jumde RP, da Costa RM, Ropponen HK, Blasco B, Piddock LJ. Extending the Potency and Lifespan of Antibiotics: Inhibitors of Gram-Negative Bacterial Efflux Pumps. ACS Infect Dis 2024; 10:1458-1482. [PMID: 38661541 PMCID: PMC11091901 DOI: 10.1021/acsinfecdis.4c00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/14/2024] [Accepted: 03/20/2024] [Indexed: 04/26/2024]
Abstract
Efflux is a natural process found in all prokaryotic and eukaryotic cells that removes a diverse range of substrates from inside to outside. Many antibiotics are substrates of bacterial efflux pumps, and modifications to the structure or overexpression of efflux pumps are an important resistance mechanism utilized by many multidrug-resistant bacteria. Therefore, chemical inhibition of bacterial efflux to revitalize existing antibiotics has been considered a promising approach for antimicrobial chemotherapy over two decades, and various strategies have been employed. In this review, we provide an overview of bacterial multidrug resistance (MDR) efflux pumps, of which the resistance nodulation division (RND) efflux pumps are considered the most clinically relevant in Gram-negative bacteria, and describe over 50 efflux inhibitors that target such systems. Although numerous efflux inhibitors have been identified to date, none have progressed into clinical use because of formulation, toxicity, and pharmacokinetic issues or a narrow spectrum of inhibition. For these reasons, the development of efflux inhibitors has been considered a difficult and complex area of research, and few active preclinical studies on efflux inhibitors are in progress. However, recently developed tools, including but not limited to computational tools including molecular docking models, offer hope that further research on efflux inhibitors can be a platform for research and development of new bacterial efflux inhibitors.
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Affiliation(s)
- Maëlle Duffey
- Global
Antibiotic Research & Development Partnership (GARDP), Chemin Camille-Vidart 15, 1202 Geneva, Switzerland
| | - Ravindra P. Jumde
- Global
Antibiotic Research & Development Partnership (GARDP), Chemin Camille-Vidart 15, 1202 Geneva, Switzerland
| | - Renata M.A. da Costa
- Global
Antibiotic Research & Development Partnership (GARDP), Chemin Camille-Vidart 15, 1202 Geneva, Switzerland
| | - Henni-Karoliina Ropponen
- Global
Antibiotic Research & Development Partnership (GARDP), Chemin Camille-Vidart 15, 1202 Geneva, Switzerland
| | - Benjamin Blasco
- Global
Antibiotic Research & Development Partnership (GARDP), Chemin Camille-Vidart 15, 1202 Geneva, Switzerland
| | - Laura J.V. Piddock
- Global
Antibiotic Research & Development Partnership (GARDP), Chemin Camille-Vidart 15, 1202 Geneva, Switzerland
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2
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Liu Y, Van Horn AM, Pham MTN, Dinh BNN, Chen R, Raphael SDR, Paulino A, Thaker K, Somadder A, Frost DJ, Menke CC, Slimak ZC, Slonczewski JL. Fitness trade-offs of multidrug efflux pumps in Escherichia coli K-12 in acid or base, and with aromatic phytochemicals. Appl Environ Microbiol 2024; 90:e0209623. [PMID: 38289137 PMCID: PMC10880634 DOI: 10.1128/aem.02096-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 12/14/2023] [Indexed: 02/22/2024] Open
Abstract
Multidrug efflux pumps are the frontline defense mechanisms of Gram-negative bacteria, yet little is known of their relative fitness trade-offs under gut conditions such as low pH and the presence of antimicrobial food molecules. Low pH contributes to the proton-motive force (PMF) that drives most efflux pumps. We show how the PMF-dependent pumps AcrAB-TolC, MdtEF-TolC, and EmrAB-TolC undergo selection at low pH and in the presence of membrane-permeant phytochemicals. Competition assays were performed by flow cytometry of co-cultured Escherichia coli K-12 strains possessing or lacking a given pump complex. All three pumps showed negative selection under conditions that deplete PMF (pH 5.5 with carbonyl cyanide 3-chlorophenylhydrazone or at pH 8.0). At pH 5.5, selection against AcrAB-TolC was increased by aromatic acids, alcohols, and related phytochemicals such as methyl salicylate. The degree of fitness cost for AcrA was correlated with the phytochemical's lipophilicity (logP). Methyl salicylate and salicylamide selected strongly against AcrA, without genetic induction of drug resistance regulons. MdtEF-TolC and EmrAB-TolC each had a fitness cost at pH 5.5, but salicylate or benzoate made the fitness contribution positive. Pump fitness effects were not explained by gene expression (measured by digital PCR). Between pH 5.5 and 8.0, acrA and emrA were upregulated in the log phase, whereas mdtE expression was upregulated in the transition-to-stationary phase and at pH 5.5 in the log phase. Methyl salicylate did not affect pump gene expression. Our results suggest that lipophilic non-acidic molecules select against a major efflux pump without inducing antibiotic resistance regulons.IMPORTANCEFor drugs that are administered orally, we need to understand how ingested phytochemicals modulate drug resistance in our gut microbiome. Bacteria maintain low-level resistance by proton-motive force (PMF)-driven pumps that efflux many different antibiotics and cell waste products. These pumps play a key role in bacterial defense by conferring resistance to antimicrobial agents at first exposure while providing time for a pathogen to evolve resistance to higher levels of the antibiotic exposed. Nevertheless, efflux pumps confer energetic costs due to gene expression and pump energy expense. The bacterial PMF includes the transmembrane pH difference (ΔpH), which may be depleted by permeant acids and membrane disruptors. Understanding the fitness costs of efflux pumps may enable us to develop resistance breakers, that is, molecules that work together with antibiotics to potentiate their effect. Non-acidic aromatic molecules have the advantage that they avoid the Mar-dependent induction of regulons conferring other forms of drug resistance. We show that different pumps have distinct selection criteria, and we identified non-acidic aromatic molecules as promising candidates for drug resistance breakers.
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Affiliation(s)
- Yangyang Liu
- Department of Biology, Kenyon College, Gambier, Ohio, USA
| | | | | | | | - Rachel Chen
- Department of Biology, Kenyon College, Gambier, Ohio, USA
| | | | | | - Kavya Thaker
- Department of Biology, Kenyon College, Gambier, Ohio, USA
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Resende DISP, Durães F, Zubarioglu S, Freitas-Silva J, Szemerédi N, Pinto M, Pinto E, Martins da Costa P, Spengler G, Sousa E. Antibacterial Potential of Symmetrical Twin-Drug 3,6-Diaminoxanthones. Pharmaceuticals (Basel) 2024; 17:209. [PMID: 38399424 PMCID: PMC10891989 DOI: 10.3390/ph17020209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/20/2024] [Accepted: 01/27/2024] [Indexed: 02/25/2024] Open
Abstract
Global health faces a significant issue with the rise of infectious diseases caused by bacteria, fungi, viruses, and parasites. The increasing number of multi-drug resistant microbial pathogens severely threatens public health worldwide. Antibiotic-resistant pathogenic bacteria, in particular, present a significant challenge. Therefore, there is an urgent need to identify new potential antimicrobial targets and discover new chemical entities that can potentially reverse bacterial resistance. The main goal of this research work was to create and develop a library of 3,6-disubstituted xanthones based on twin drugs and molecular extension approaches to inhibit the activity of efflux pumps. The process involved synthesizing 3,6-diaminoxanthones through the reaction of 9-oxo-9H-xanthene-3,6-diyl bis(trifluoromethanesulfonate) with various primary and secondary amines. The resulting 3,6-disubstituted xanthone derivatives were then tested for their in vitro antimicrobial properties against a range of pathogenic strains and their efficacy in inhibiting the activity of efflux pumps, biofilm formation, and quorum-sensing. Several compounds have exhibited effective antibacterial properties against the Gram-positive bacterial species tested. Xanthone 16, in particular, has demonstrated exceptional efficacy with a remarkable MIC of 11 µM (4 µg/mL) against reference strains Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212, and 25 µM (9 µg/mL) against methicillin-resistant S. aureus 272123. Furthermore, some derivatives have shown potential as antibiofilm agents in a crystal violet assay. The ethidium bromide accumulation assay pinpointed certain compounds inhibiting bacterial efflux pumps. The cytotoxic effect of the most promising compounds was examined in mouse fibroblast cell line NIH/3T3, and two monoamine substituted xanthone derivatives with a hydroxyl substituent did not exhibit any cytotoxicity. Overall, the nature of the substituent was critical in determining the antimicrobial spectra of aminated xanthones.
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Affiliation(s)
- Diana I. S. P. Resende
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - Fernando Durães
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - Sidika Zubarioglu
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Joana Freitas-Silva
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
- ICBAS—Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Nikoletta Szemerédi
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center and Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary
| | - Madalena Pinto
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - Eugénia Pinto
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
- Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Paulo Martins da Costa
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
- ICBAS—Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Gabriella Spengler
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center and Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary
| | - Emília Sousa
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
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Wilhelm J, Pos KM. Molecular insights into the determinants of substrate specificity and efflux inhibition of the RND efflux pumps AcrB and AdeB. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001438. [PMID: 38358391 PMCID: PMC10924465 DOI: 10.1099/mic.0.001438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/30/2024] [Indexed: 02/16/2024]
Abstract
Gram-negative bacterial members of the Resistance Nodulation and cell Division (RND) superfamily form tripartite efflux pump systems that span the cell envelope. One of the intriguing features of the multiple drug efflux members of this superfamily is their ability to recognize different classes of antibiotics, dyes, solvents, bile salts, and detergents. This review provides an overview of the molecular mechanisms of multiple drug efflux catalysed by the tripartite RND efflux system AcrAB-TolC from Eschericha coli. The determinants for sequential or simultaneous multiple substrate binding and efflux pump inhibitor binding are discussed. A comparison is made with the determinants for substrate binding of AdeB from Acinetobacter baumannii, which acts within the AdeABC multidrug efflux system. There is an apparent general similarity between the structures of AcrB and AdeB and their substrate specificity. However, the presence of distinct conformational states and different drug efflux capacities as revealed by single-particle cryo-EM and mutational analysis suggest that the drug binding and transport features exhibited by AcrB may not be directly extrapolated to the homolog AdeB efflux pump.
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Affiliation(s)
- Julia Wilhelm
- Institute of Biochemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
| | - Klaas Martinus Pos
- Institute of Biochemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
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Shobana R, Thahirunnisa JH, Sivaprakash S, Amali AJ, Solomon AP, Suresh D. Effect of palladium(II) complexes on NorA efflux pump inhibition and resensitization of fluoroquinolone-resistant Staphylococcus aureus: in vitro and in silico approach. Front Cell Infect Microbiol 2024; 13:1340135. [PMID: 38292858 PMCID: PMC10825952 DOI: 10.3389/fcimb.2023.1340135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 12/20/2023] [Indexed: 02/01/2024] Open
Abstract
Staphylococcus aureus leads to diverse infections, and their treatment relies on the use of antibiotics. Nevertheless, the rise of antibiotic resistance poses an escalating challenge and various mechanisms contribute to antibiotic resistance, including modifications to drug targets, enzymatic deactivation of drugs, and increased efflux of antibiotics. Hence, the quest for innovative antimicrobial solutions has intensified in the face of escalating antibiotic resistance and the looming threat of superbugs. The NorA protein of S. aureus, classified as an efflux pump within the major facilitator superfamily, when overexpressed, extrudes various substances, including fluoroquinolones (such as ciprofloxacin) and quaternary ammonium. Addressing this, the unexplored realm of inorganic and organometallic compounds in medicinal chemistry holds promise. Notably, the study focused on investigating two different series of palladium-based metal complexes consisting of QSL_PA and QSL_PB ligands to identify a potent NorA efflux pump inhibitor that can restore the susceptibility to fluoroquinolone antibiotics. QSL_Pd5A was identified as a potent efflux pump inhibitor from the real-time efflux assay. QSL_Pd5A also resensitized SA1199B to ciprofloxacin at a low concentration of 0.125 µg/mL without elucidating cytotoxicity on the NRK-62E cell line. The in vitro findings were substantiated by docking results, indicating favorable interactions between QSL_Pd5A and the NorA efflux pump.
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Affiliation(s)
- Rajaramon Shobana
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Jaffer Hussain Thahirunnisa
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Selvam Sivaprakash
- Organometallics and Catalysis Laboratory, Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu, India
| | - Arlin Jose Amali
- Organometallics and Catalysis Laboratory, Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu, India
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Devarajan Suresh
- Organometallics and Catalysis Laboratory, Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu, India
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6
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Allgood SC, Su CC, Crooks AL, Meyer CT, Zhou B, Betterton MD, Barbachyn MR, Yu EW, Detweiler CS. Bacterial efflux pump modulators prevent bacterial growth in macrophages and under broth conditions that mimic the host environment. mBio 2023; 14:e0249223. [PMID: 37921493 PMCID: PMC10746280 DOI: 10.1128/mbio.02492-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 11/04/2023] Open
Abstract
New approaches for combating microbial infections are needed. One strategy for disrupting pathogenesis involves developing compounds that interfere with bacterial virulence. A critical molecular determinant of virulence for Gram-negative bacteria are efflux pumps of the resistance-nodulation-division family, which includes AcrAB-TolC. We previously identified small molecules that bind AcrB, inhibit AcrAB-TolC, and do not appear to damage membranes. These efflux pump modulators (EPMs) were discovered in an in-cell screening platform called SAFIRE (Screen for Anti-infectives using Fluorescence microscopy of IntracellulaR Enterobacteriaceae). SAFIRE identifies compounds that disrupt the growth of a Gram-negative human pathogen, Salmonella enterica serotype Typhimurium (S. Typhimurium), in macrophages. We used medicinal chemistry to iteratively design ~200 EPM35 analogs and test them for activity in SAFIRE, generating compounds with nanomolar potency. Analogs were demonstrated to bind AcrB in a substrate binding pocket by cryo-electron microscopy. Despite having amphipathic structures, the EPM analogs do not disrupt membrane voltage, as monitored by FtsZ localization to the cell septum. The EPM analogs had little effect on bacterial growth in standard Mueller Hinton Broth. However, under broth conditions that mimic the micro-environment of the macrophage phagosome, acrAB is required for growth, the EPM analogs are bacteriostatic, and the EPM analogs increase the potency of antibiotics. These data suggest that under macrophage-like conditions, the EPM analogs prevent the export of a toxic bacterial metabolite(s) through AcrAB-TolC. Thus, compounds that bind AcrB could disrupt infection by specifically interfering with the export of bacterial toxic metabolites, host defense factors, and/or antibiotics.IMPORTANCEBacterial efflux pumps are critical for resistance to antibiotics and for virulence. We previously identified small molecules that inhibit efflux pumps (efflux pump modulators, EPMs) and prevent pathogen replication in host cells. Here, we used medicinal chemistry to increase the activity of the EPMs against pathogens in cells into the nanomolar range. We show by cryo-electron microscopy that these EPMs bind an efflux pump subunit. In broth culture, the EPMs increase the potency (activity), but not the efficacy (maximum effect), of antibiotics. We also found that bacterial exposure to the EPMs appear to enable the accumulation of a toxic metabolite that would otherwise be exported by efflux pumps. Thus, inhibitors of bacterial efflux pumps could interfere with infection not only by potentiating antibiotics, but also by allowing toxic waste products to accumulate within bacteria, providing an explanation for why efflux pumps are needed for virulence in the absence of antibiotics.
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Affiliation(s)
- Samual C. Allgood
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Amy L. Crooks
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Christian T. Meyer
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
- Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado, USA
- Duet Biosystems, Nashville, Tennessee, USA
- Antimicrobial Research Consortium (ARC) Labs, Boulder, Colorado, USA
| | - Bojun Zhou
- Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - Meredith D. Betterton
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
- Department of Physics, University of Colorado, Boulder, Colorado, USA
- Center for Computational Biology, Flatiron Institute, New York, New York, USA
| | | | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Corrella S. Detweiler
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
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7
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Allgood SC, Su CC, Crooks AL, Meyer CT, Zhou B, Betterton MD, Barbachyn MR, Yu EW, Detweiler CS. Bacterial Efflux Pump Modulators Prevent Bacterial Growth in Macrophages and Under Broth Conditions that Mimic the Host Environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.20.558466. [PMID: 37786697 PMCID: PMC10541609 DOI: 10.1101/2023.09.20.558466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
New approaches for combatting microbial infections are needed. One strategy for disrupting pathogenesis involves developing compounds that interfere with bacterial virulence. A critical molecular determinant of virulence for Gram-negative bacteria are efflux pumps of the resistance-nodulation-division (RND) family, which includes AcrAB-TolC. We previously identified small molecules that bind AcrB, inhibit AcrAB-TolC, and do not appear to damage membranes. These efflux pump modulators (EPMs) were discovered in an in-cell screening platform called SAFIRE (Screen for Anti-infectives using Fluorescence microscopy of IntracellulaR Enterobacteriaceae). SAFIRE identifies compounds that disrupt the growth of a Gram-negative human pathogen, Salmonella enterica serotype Typhimurium (S. Typhimurium) in macrophages. We used medicinal chemistry to iteratively design ~200 EPM35 analogs and test them for activity in SAFIRE, generating compounds with nanomolar potency. Analogs were demonstrated to bind AcrB in a substrate binding pocket by cryo-electron microscopy (cryo-EM). Despite having amphipathic structures, the EPM analogs do not disrupt membrane voltage, as monitored by FtsZ localization to the cell septum. The EPM analogs had little effect on bacterial growth in standard Mueller Hinton Broth. However, under broth conditions that mimic the micro-environment of the macrophage phagosome, acrAB is required for growth, the EPM analogs are bacteriostatic, and increase the potency of antibiotics. These data suggest that under macrophage-like conditions the EPM analogs prevent the export of a toxic bacterial metabolite(s) through AcrAB-TolC. Thus, compounds that bind AcrB could disrupt infection by specifically interfering with the export of bacterial toxic metabolites, host defense factors, and/or antibiotics.
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Affiliation(s)
- Samual C Allgood
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Amy L Crooks
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Christian T Meyer
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
- Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, USA
- Duet Biosystems, Nashville, TN, USA
- Antimicrobial Research Consortium (ARC) Labs, Boulder, CO, USA
| | - Bojun Zhou
- Department of Physics, University of Colorado, Boulder, CO, USA
| | - Meredith D Betterton
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
- Center for Computational Biology, Flatiron Institute, New York, NY, USA
| | | | - Edward W Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Corrella S Detweiler
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
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8
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Shakibaie MR, Modaresi F, Azizi O, Tadjrobehkar O, Ghaemi MM. Amphiphilic peptide Mastoparan-B induces conformational changes within the AdeB efflux pump, down-regulates adeB gene expression, and restores antibiotic susceptibility in an MDR strain of Acinetobacter baumannii. Proteins 2023; 91:1205-1221. [PMID: 37455426 DOI: 10.1002/prot.26539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 05/11/2023] [Accepted: 05/30/2023] [Indexed: 07/18/2023]
Abstract
Mastoparan B (MP-B) is an amphiphilic peptide with a potent antimicrobial activity against most Gram-negative bacteria. However, there is little information available on the inhibition of the Acinetobacter baumannii resistance-nodulation-cell-division (RND) efflux pump using this antimicrobial peptide. Here, we carried out a series of in-silico experiments to find the mechanisms underlying the anti-efflux activity of MP-B using a multi-drug resistant (MDR) strain of A. baumannii (AB). According to our findings, MP-B demonstrated a potent antibacterial activity against an MDR-AB (minimum inhibitory concentration [MIC] = 1 μg/mL) followed by a 20-fold reduction in the adeB gene expression in the presence of sub-MIC of this peptide. Using Groningen Machine for Chemicals Simulation (GROMACS) via PyMOL Graphical User Interface (GUI), (we observed that, the AdeB transporter had conserved helix-turn-helix regions and a tight pore rich in Phe and Ala residues. To understand how inhibition of the AdeB is achieved, we generated 20 apo-MP-B poses using the InterPep and SiteMap tools. The high-quality model was created by homology modeling and used for docking via AutoDock/Vina to identify the MP-B binding sites. We established that the most apo-MP-B formed H-bonds to the backbone of five amino acids in the Helix-5. As a result, the dihedral angles of the involved amino acids shift by 9.0-9.6 Ǻ, causing a change in the conformation of the AdeB protein. This led to helix conformation stereoisomerization and block the AdeB activity. MP-B presumably has dual mechanisms. (1) It blocks the AdeB transporter by changing its conformation. (2) MP-B influences the adeB gene expression by binding to G-protein which laterally controls efflux regulators like MarA, RamA, SoxS, and Rob proteins.
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Affiliation(s)
- Mohammad Reza Shakibaie
- Department of Microbiology and Virology, Kerman University of Medical Sciences, Kerman, Iran
- Gastroenterology Hepatology Research Center, Institute of Basic and Clinical Physiology, Kerman University of Medical Sciences, Kerman, Iran
| | - Farzan Modaresi
- Department of Microbiology, School of Medicine, Jahrom University of Medical Sciences, Jahrom, Iran
| | - Omid Azizi
- Department of Laboratory Sciences, and Health Sciences Research center, Torbat Heydariyeh University of Medical Sciences, Torbate Heydarieh, Iran
| | - Omid Tadjrobehkar
- Department of Microbiology and Virology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Mehdi Ghaemi
- Medical Informatics Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran
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Gervasoni S, Mehla J, Bergen CR, Leus IV, Margiotta E, Malloci G, Bosin A, Vargiu AV, Lomovskaya O, Rybenkov VV, Ruggerone P, Zgurskaya HI. Molecular determinants of avoidance and inhibition of Pseudomonas aeruginosa MexB efflux pump. mBio 2023; 14:e0140323. [PMID: 37493633 PMCID: PMC10470492 DOI: 10.1128/mbio.01403-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 06/12/2023] [Indexed: 07/27/2023] Open
Abstract
Transporters of the resistance-nodulation-cell division (RND) superfamily of proteins are the dominant multidrug efflux power of Gram-negative bacteria. The major RND efflux pump of Pseudomonas aeruginosa is MexAB-OprM, in which the inner membrane transporter MexB is responsible for the recognition and binding of compounds. The high importance of this pump in clinical antibiotic resistance made it a subject of intense investigations and a promising target for the discovery of efflux pump inhibitors. This study is focused on a series of peptidomimetic compounds developed as effective inhibitors of MexAB-OprM. We performed multi-copy molecular dynamics simulations, machine-learning (ML) analyses, and site-directed mutagenesis of MexB to investigate interactions of MexB with representatives of efflux avoiders, substrates, and inhibitors. The analysis of both direct and water-mediated protein-ligand interactions revealed characteristic patterns for each class, highlighting significant differences between them. We found that efflux avoiders poorly interact with the access binding site of MexB, and inhibition engages amino acid residues that are not directly involved in binding and transport of substrates. In agreement, machine-learning models selected different residues predictive of MexB substrates and inhibitors. The differences in interactions were further validated by site-directed mutagenesis. We conclude that the substrate translocation and inhibition pathways of MexB split at the interface (between the main putative binding sites) and at the deep binding pocket and that interactions outside of the hydrophobic patch contribute to the inhibition of MexB. This molecular-level information could help in the rational design of new inhibitors and antibiotics less susceptible to the efflux mechanism. IMPORTANCE Multidrug transporters recognize and expel from cells a broad range of ligands including their own inhibitors. The difference between the substrate translocation and inhibition routes remains unclear. In this study, machine learning and computational and experimental approaches were used to understand dynamics of MexB interactions with its ligands. Our results show that some ligands engage a certain combination of polar and charged residues in MexB binding sites to be effectively expelled into the exit funnel, whereas others engage aromatic and hydrophobic residues that slow down or hinder the next step in the transporter cycle. These findings suggest that all MexB ligands fit into this substrate-inhibitor spectrum depending on their physico-chemical structures and properties.
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Affiliation(s)
- Silvia Gervasoni
- Department of Physics, University of Cagliari, Monserrato, Italy
| | - Jitender Mehla
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Charles R. Bergen
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Inga V. Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Enrico Margiotta
- Department of Physics, University of Cagliari, Monserrato, Italy
| | - Giuliano Malloci
- Department of Physics, University of Cagliari, Monserrato, Italy
| | - Andrea Bosin
- Department of Physics, University of Cagliari, Monserrato, Italy
| | | | | | - Valentin V. Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, Monserrato, Italy
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
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10
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Avakh A, Grant GD, Cheesman MJ, Kalkundri T, Hall S. The Art of War with Pseudomonas aeruginosa: Targeting Mex Efflux Pumps Directly to Strategically Enhance Antipseudomonal Drug Efficacy. Antibiotics (Basel) 2023; 12:1304. [PMID: 37627724 PMCID: PMC10451789 DOI: 10.3390/antibiotics12081304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 07/26/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa) poses a grave clinical challenge due to its multidrug resistance (MDR) phenotype, leading to severe and life-threatening infections. This bacterium exhibits both intrinsic resistance to various antipseudomonal agents and acquired resistance against nearly all available antibiotics, contributing to its MDR phenotype. Multiple mechanisms, including enzyme production, loss of outer membrane proteins, target mutations, and multidrug efflux systems, contribute to its antimicrobial resistance. The clinical importance of addressing MDR in P. aeruginosa is paramount, and one pivotal determinant is the resistance-nodulation-division (RND) family of drug/proton antiporters, notably the Mex efflux pumps. These pumps function as crucial defenders, reinforcing the emergence of extensively drug-resistant (XDR) and pandrug-resistant (PDR) strains, which underscores the urgency of the situation. Overcoming this challenge necessitates the exploration and development of potent efflux pump inhibitors (EPIs) to restore the efficacy of existing antipseudomonal drugs. By effectively countering or bypassing efflux activities, EPIs hold tremendous potential for restoring the antibacterial activity against P. aeruginosa and other Gram-negative pathogens. This review focuses on concurrent MDR, highlighting the clinical significance of efflux pumps, particularly the Mex efflux pumps, in driving MDR. It explores promising EPIs and delves into the structural characteristics of the MexB subunit and its substrate binding sites.
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Affiliation(s)
| | | | | | | | - Susan Hall
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, QLD 4222, Australia; (A.A.); (G.D.G.); (M.J.C.); (T.K.)
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11
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Almeida MC, Szemerédi N, Durães F, Long S, Resende DISP, Martins da Costa P, Pinto M, Spengler G, Sousa E. Effect of Indole-Containing Pyrazino[2,1- b]quinazoline-3,6-diones in the Virulence of Resistant Bacteria. Antibiotics (Basel) 2023; 12:antibiotics12050922. [PMID: 37237825 DOI: 10.3390/antibiotics12050922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Drug resistance is rising to alarming levels, constituting one of the major threats to global health. The overexpression of efflux pumps and the formation of biofilms constitute two of the most common resistance mechanisms, favoring the virulence of bacteria. Therefore, the research and development of effective antimicrobial agents that can also counteract resistance mechanisms are extremely important. Pyrazino[2,1-b]quinazoline-3,6-diones, from marine and terrestrial organisms and simpler synthetic analogues, were recently disclosed by us as having relevant antimicrobial properties. In this study, using a multi-step approach, it was possible to synthesize new pyrazino[2,1-b]quinazoline-3,6-diones focusing on compounds with fluorine substituents since, to the best of our knowledge, the synthesis of fluorinated fumiquinazoline derivatives had not been attempted before. The new synthesized derivatives were screened for antibacterial activity and, along with previously synthetized pyrazino[2,1-b]quinazoline-3,6-diones, were characterized for their antibiofilm and efflux-pump-inhibiting effects against representative bacterial species and relevant resistant clinical strains. Several compounds showed relevant antibacterial activity against the tested Gram-positive bacterial species with MIC values in the range of 12.5-77 μM. Furthermore, some derivatives showed promising results as antibiofilm agents in a crystal violet assay. The results of the ethidium bromide accumulation assay suggested that some compounds could potentially inhibit bacterial efflux pumps.
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Affiliation(s)
- Mariana C Almeida
- Laboratório de Química Orgânica e Farmacêutica, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- CIIMAR--Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Nikoletta Szemerédi
- Department of Medical Microbiology, Albert Szent-Gyorgyi Health Center and Albert Szent-Gyorgyi Medical School, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary
| | - Fernando Durães
- Laboratório de Química Orgânica e Farmacêutica, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- CIIMAR--Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Solida Long
- Laboratório de Química Orgânica e Farmacêutica, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- Department of Bioengineering, Royal University of Phnom Penh, Russian Confederation Blvd, Phnom Penh 12156, Cambodia
| | - Diana I S P Resende
- Laboratório de Química Orgânica e Farmacêutica, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- CIIMAR--Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Paulo Martins da Costa
- CIIMAR--Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Madalena Pinto
- Laboratório de Química Orgânica e Farmacêutica, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- CIIMAR--Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Gabriella Spengler
- Department of Medical Microbiology, Albert Szent-Gyorgyi Health Center and Albert Szent-Gyorgyi Medical School, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary
| | - Emília Sousa
- Laboratório de Química Orgânica e Farmacêutica, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- CIIMAR--Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
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12
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Darby EM, Trampari E, Siasat P, Gaya MS, Alav I, Webber MA, Blair JMA. Molecular mechanisms of antibiotic resistance revisited. Nat Rev Microbiol 2023; 21:280-295. [PMID: 36411397 DOI: 10.1038/s41579-022-00820-y] [Citation(s) in RCA: 190] [Impact Index Per Article: 190.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2022] [Indexed: 11/22/2022]
Abstract
Antibiotic resistance is a global health emergency, with resistance detected to all antibiotics currently in clinical use and only a few novel drugs in the pipeline. Understanding the molecular mechanisms that bacteria use to resist the action of antimicrobials is critical to recognize global patterns of resistance and to improve the use of current drugs, as well as for the design of new drugs less susceptible to resistance development and novel strategies to combat resistance. In this Review, we explore recent advances in understanding how resistance genes contribute to the biology of the host, new structural details of relevant molecular events underpinning resistance, the identification of new resistance gene families and the interactions between different resistance mechanisms. Finally, we discuss how we can use this information to develop the next generation of antimicrobial therapies.
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Affiliation(s)
- Elizabeth M Darby
- College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | | | - Pauline Siasat
- College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | | | - Ilyas Alav
- College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Mark A Webber
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK.
- Medical School, University of East Anglia, Norwich Research Park, Norwich, UK.
| | - Jessica M A Blair
- College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK.
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13
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Baran A, Kwiatkowska A, Potocki L. Antibiotics and Bacterial Resistance-A Short Story of an Endless Arms Race. Int J Mol Sci 2023; 24:ijms24065777. [PMID: 36982857 PMCID: PMC10056106 DOI: 10.3390/ijms24065777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/10/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
Despite the undisputed development of medicine, antibiotics still serve as first-choice drugs for patients with infectious disorders. The widespread use of antibiotics results from a wide spectrum of their actions encompassing mechanisms responsible for: the inhibition of bacterial cell wall biosynthesis, the disruption of cell membrane integrity, the suppression of nucleic acids and/or proteins synthesis, as well as disturbances of metabolic processes. However, the widespread availability of antibiotics, accompanied by their overprescription, acts as a double-edged sword, since the overuse and/or misuse of antibiotics leads to a growing number of multidrug-resistant microbes. This, in turn, has recently emerged as a global public health challenge facing both clinicians and their patients. In addition to intrinsic resistance, bacteria can acquire resistance to particular antimicrobial agents through the transfer of genetic material conferring resistance. Amongst the most common bacterial resistance strategies are: drug target site changes, increased cell wall permeability to antibiotics, antibiotic inactivation, and efflux pumps. A better understanding of the interplay between the mechanisms of antibiotic actions and bacterial defense strategies against particular antimicrobial agents is crucial for developing new drugs or drug combinations. Herein, we provide a brief overview of the current nanomedicine-based strategies that aim to improve the efficacy of antibiotics.
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Affiliation(s)
- Aleksandra Baran
- Department of Biotechnology, College of Natural Sciences, University of Rzeszów, Pigonia 1, 35-310 Rzeszow, Poland
| | - Aleksandra Kwiatkowska
- Institute of Physical Culture Studies, College of Medical Sciences, University of Rzeszów, ul. Towarnickiego 3, 35-959 Rzeszów, Poland
| | - Leszek Potocki
- Department of Biotechnology, College of Natural Sciences, University of Rzeszów, Pigonia 1, 35-310 Rzeszow, Poland
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14
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Li T, Wang Z, Guo J, de la Fuente-Nunez C, Wang J, Han B, Tao H, Liu J, Wang X. Bacterial resistance to antibacterial agents: Mechanisms, control strategies, and implications for global health. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 860:160461. [PMID: 36435256 DOI: 10.1016/j.scitotenv.2022.160461] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 11/19/2022] [Accepted: 11/20/2022] [Indexed: 06/16/2023]
Abstract
The spread of bacterial drug resistance has posed a severe threat to public health globally. Here, we cover bacterial resistance to current antibacterial drugs, including traditional herbal medicines, conventional antibiotics, and antimicrobial peptides. We summarize the influence of bacterial drug resistance on global health and its economic burden while highlighting the resistance mechanisms developed by bacteria. Based on the One Health concept, we propose 4A strategies to combat bacterial resistance, including prudent Application of antibacterial agents, Administration, Assays, and Alternatives to antibiotics. Finally, we identify several opportunities and unsolved questions warranting future exploration for combating bacterial resistance, such as predicting genetic bacterial resistance through the use of more effective techniques, surveying both genetic determinants of bacterial resistance and the transmission dynamics of antibiotic resistance genes (ARGs).
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Affiliation(s)
- Ting Li
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, PR China; State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, No. 20, Dongda Street, Fengtai District, Beijing 100071, PR China
| | - Zhenlong Wang
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, PR China
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St Lucia, Queensland 4072, Australia.
| | - Cesar de la Fuente-Nunez
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America; Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States of America; Penn Institute for Computational Science, University of Pennsylvania, Philadelphia, PA, United States of America.
| | - Jinquan Wang
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, PR China
| | - Bing Han
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, PR China
| | - Hui Tao
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, PR China
| | - Jie Liu
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, PR China
| | - Xiumin Wang
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, PR China.
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15
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Chetri S. The culmination of multidrug-resistant efflux pumps vs. meager antibiotic arsenal era: Urgent need for an improved new generation of EPIs. Front Microbiol 2023; 14:1149418. [PMID: 37138605 PMCID: PMC10149990 DOI: 10.3389/fmicb.2023.1149418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 03/13/2023] [Indexed: 05/05/2023] Open
Abstract
Efflux pumps function as an advanced defense system against antimicrobials by reducing the concentration of drugs inside the bacteria and extruding the substances outside. Various extraneous substances, including antimicrobials, toxic heavy metals, dyes, and detergents, have been removed by this protective barrier composed of diverse transporter proteins found in between the cell membrane and the periplasm within the bacterial cell. In this review, multiple efflux pump families have been analytically and widely outlined, and their potential applications have been discussed in detail. Additionally, this review also discusses a variety of biological functions of efflux pumps, including their role in the formation of biofilms, quorum sensing, their survivability, and the virulence in bacteria, and the genes/proteins associated with efflux pumps have also been explored for their potential relevance to antimicrobial resistance and antibiotic residue detection. A final discussion centers around efflux pump inhibitors, particularly those derived from plants.
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16
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Schuster S, Vavra M, Kern WV. A Screening of Antimalarials Extends the Range of Known Escherichia coli AcrB Efflux Substrates and Reveals Two Candidates with Antimicrobial Drug-Enhancing Activity. Microb Drug Resist 2022; 28:1065-1070. [PMID: 36255442 DOI: 10.1089/mdr.2022.0138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Efflux by resistance nodulation cell division transporters, such as AcrAB-TolC in Escherichia coli, substantially contributes to the development of Gram-negative multidrug resistance. Therefore, the finding of compounds that counteract efflux is an urgent goal in the fight against infectious diseases. Previously, an efflux inhibitory activity of the antimalarials mefloquine and artesunate was reported. In this study, we have investigated further antimalarials regarding efflux by AcrB, the pumping part of AcrAB-TolC, and their drug-enhancing potency in E. coli. We show that 10 of the 24 drugs tested are substrates of the multidrug efflux pump AcrB. Among them, tafenoquine and proguanil, when used at subinhibitory concentrations, caused an at least 4- and up to 24-fold enhancement in susceptibility to 6 and 14 antimicrobial agents, respectively. Both antimalarials are able to increase the intracellular accumulation of Hoechst 33342, with proguanil showing similar effectiveness as the efflux inhibitor 1-(1-naphthylmethyl)piperazine. In the case of proguanil, AcrB-dependent efflux inhibition could also be demonstrated in a real-time efflux assay. In addition to presenting new AcrB substrates, our study reveals two previously unknown efflux inhibitors among antimalarials. Particularly proguanil appears as a promising candidate and its chemical scaffold might be further optimized for repurposing as antimicrobial drug enhancer.
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Affiliation(s)
- Sabine Schuster
- Division of Infectious Diseases, Department of Medicine II, University Hospital and Medical Center, Freiburg, Germany
| | - Martina Vavra
- Division of Infectious Diseases, Department of Medicine II, University Hospital and Medical Center, Freiburg, Germany
| | - Winfried V Kern
- Division of Infectious Diseases, Department of Medicine II, University Hospital and Medical Center, Freiburg, Germany.,Faculty of Medicine, Albert-Ludwigs-University, Freiburg, Germany
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17
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New Chalcone-Triazole Hybrids with Promising Antimicrobial Activity in Multidrug Resistance Strains. Int J Mol Sci 2022; 23:ijms232214291. [PMID: 36430768 PMCID: PMC9697807 DOI: 10.3390/ijms232214291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/09/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022] Open
Abstract
Resistance to antibiotics is an emerging problem worldwide, which leads to an increase in morbidity and mortality rates. Several mechanisms are attributed to bacterial resistance, overexpression of efflux pumps being one of the most prominent. As an attempt to develop new effective antimicrobial drugs, which could be able to act against resistant bacterial strains and considering the antimicrobial potential of flavonoids and triazolyl flavonoid derivatives, in particular chalcones, a small library of chalcone derivatives was synthesized and evaluated for its potential to act as antimicrobials and/or adjuvants in combination with antibiotics towards resistant bacteria. Although only compound 7 was able to act as antibacterial, compounds 1, 2, 4, 5, 7, and 9 revealed to be able to potentiate the activity of antibiotics in resistant bacteria. Moreover, five compounds (3, 5-8) demonstrated to be effective inhibitors of efflux pumps in Salmonella enterica serovar Typhimurium SL1344, and four compounds (1, 3, 7, and 10) showed higher ability than reserpine to inhibit biofilm formation of resistant Staphylococcus aureus 272123. Together, our results showed the potential of these compounds regarding reversion of bacterial resistance.
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18
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Dong N, Zeng Y, Wang Y, Liu C, Lu J, Cai C, Liu X, Chen Y, Wu Y, Fang Y, Fu Y, Hu Y, Zhou H, Cai J, Hu F, Wang S, Wang Y, Wu Y, Chen G, Shen Z, Chen S, Zhang R. Distribution and spread of the mobilised RND efflux pump gene cluster tmexCD-toprJ in clinical Gram-negative bacteria: a molecular epidemiological study. THE LANCET. MICROBE 2022; 3:e846-e856. [PMID: 36202114 DOI: 10.1016/s2666-5247(22)00221-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/05/2022] [Accepted: 07/25/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND TMexCD1-TOprJ1, which is associated with phenotypic resistance to multiple classes of antibiotics, is a transmissible resistance-nodulation-division (RND) family efflux pump. However, the prevalence and genomic and phenotypic characteristics of clinical isolates with this important resistance determinant are poorly understood. In this study, we aimed to survey tmexCD-toprJ among clinical Gram-negative isolates collected from hospitals in China between 1991 and 2020 and characterise tmexCD-toprJ-positive clinical isolates. METHODS We conducted online data retrieval and active nationwide surveillance in China to screen tmexCD-toprJ-positive strains. We characterised tmexCD-toprJ-positive clinical strains for their antimicrobial susceptibility, genetic and functional characteristics, and the potential inter-species transmission route of tmexCD-toprJ with whole genome sequencing and bioinformatics analyses. The function of tmexCD-toprJ in Pseudomonas sp and Proteus sp was investigated by tmexD gene knockdown using an isopropylthio-β-galactoside-inducible CRISPR interference system. FINDINGS Data retrieval obtained 53 strains carrying tmexCD-toprJ, comprising 32 Pseudomonas spp, 11 Klebsiella pneumoniae, one Aeromonas spp, one Citrobacter freundii, and one uncultured bacterium from diverse niches. 48 (0·64%) of 7517 clinical isolates from China, including seven Klebsiella spp, one Proteus mirabilis, and 40 Pseudomonas spp, carried tmexCD-toprJ. These isolates exhibited multidrug resistance phenotypes and co-harboured resistance genes, such as mcr and carbapenemases genes. tmexCD-toprJ was encoded on both plasmids and chromosomes in all Klebsiella spp that carried plasmid-borne tmexCD-toprJ (n=7), P mirabilis carried chromosome-borne tmexCD-toprJ, and Pseudomonas spp carried either plasmid-borne (n=19) or chromosome-borne (n=21) ones. tmexCD-toprJ had undergone clonal and horizontal transmission among clinical pathogens. Eight different types of genetic context of tmexCD-toprJ were identified, each of which was associated with different mobile elements, including IntI, IS6100, TnAs1-like, ISRor5, ISVsa3, ISCfr-like, Tn5393, and IS222-like, which might facilitate its transmission. Knockdown of tmexD led to a four times decrease in tigecycline minimum inhibitory concentrations in both Pseudomonas spp and Proteus spp. INTERPRETATION Our study provides evidence to suggest that tmexCD-toprJ contributes to the antimicrobial resistance phenotypes in different bacterial species. tmexCD-toprJ has disseminated among diverse species of clinical pathogens, which warrants timely monitoring in clinical pathogens. FUNDING National Natural Science Foundation of China, Guangdong Major Project of Basic and Applied Basic Research, Natural Science Foundation of Jiangsu Province.
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Affiliation(s)
- Ning Dong
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China; Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong Special Administrative Region, China; Department of Medical Microbiology, School of Biology and Basic Medical Science, Medical College of Soochow University, Suzhou, China
| | - Yu Zeng
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Yao Wang
- Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Congcong Liu
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Jiayue Lu
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Chang Cai
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Xue Liu
- International Cancer Center, Health Science Center, Shenzhen University, Shenzhen, China
| | - Yongkui Chen
- International Cancer Center, Health Science Center, Shenzhen University, Shenzhen, China
| | - Yuchen Wu
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Yinfei Fang
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Yulin Fu
- Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yanyan Hu
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Hongwei Zhou
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Jiachang Cai
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Fupin Hu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Shaolin Wang
- Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yang Wang
- Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yongning Wu
- National Health Commission Key Laboratory of Food Safety Risk Assessment, Food Safety Research Unit (2019RU014) of Chinese Academy of Medical Science, China National Center for Food Safety Risk Assessment, Beijing, China
| | - Gongxiang Chen
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China
| | - Zhangqi Shen
- Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Sheng Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Rong Zhang
- Department of Clinical Laboratory, The Second Affiliated Hospital Zhejiang, University School of Medicine, Zhejiang, China.
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Drug Efflux Pump Inhibitors: A Promising Approach to Counter Multidrug Resistance in Gram-Negative Pathogens by Targeting AcrB Protein from AcrAB-TolC Multidrug Efflux Pump from Escherichia coli. BIOLOGY 2022; 11:biology11091328. [PMID: 36138807 PMCID: PMC9495857 DOI: 10.3390/biology11091328] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Multidrug-resistant bacterial infections, especially that caused by Gram-negative bacteria, have posed serious health issues worldwide. Bacteria have different mechanisms that can confer multidrug resistance to bacteria, among these mechanisms are drug efflux pumps that play the main role in conferring multidrug resistance by recognizing then expelling a wide range of compounds, especially antibiotics, and reducing their concentration to sub-toxic levels. Small molecule inhibitors that target drug efflux pumps especially the AcrAB-TolC multidrug efflux pump, from E. coli, appear as a new promising and attractive approach that could increase the required accumulation of antimicrobials to eliminate bacteria as well as leading to reverse antibiotic resistance and prevent the development of resistance in clinically relevant bacterial pathogens and enhances the activity of antibiotics or prolong their effectiveness. Abstract Infections caused by multidrug resistance (MDR) of Gram-negative bacteria have become one of the most severe public health problems worldwide. The main mechanism that confers MDR to bacteria is drug efflux pumps, as they expel a wide range of compounds, especially antibiotics. Among the different types of drug efflux pumps, the resistance nodulation division (RND) superfamily confers MDR to various Gram-negative bacteria species. The AcrAB-TolC multidrug efflux pump, from E. coli, a member of RND, is the best-characterized example and an excellent model for understanding MDR because of an abundance of functional and structural data. Small molecule inhibitors that target the AcrAB-TolC drug efflux pump represent a new solution to reversing MDR in Gram-negative bacteria and restoring the efficacy of various used drugs that are clinically relevant to these pathogens, especially in the high shortage of drugs for multidrug-resistant Gram-negative bacteria. This review will investigate solutions of MDR in Gram-negative bacteria by studying the inhibition of the AcrAB-TolC multidrug efflux pump.
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Pyridylpiperazine-based allosteric inhibitors of RND-type multidrug efflux pumps. Nat Commun 2022; 13:115. [PMID: 35013254 PMCID: PMC8749003 DOI: 10.1038/s41467-021-27726-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 12/02/2021] [Indexed: 12/30/2022] Open
Abstract
Efflux transporters of the RND family confer resistance to multiple antibiotics in Gram-negative bacteria. Here, we identify and chemically optimize pyridylpiperazine-based compounds that potentiate antibiotic activity in E. coli through inhibition of its primary RND transporter, AcrAB-TolC. Characterisation of resistant E. coli mutants and structural biology analyses indicate that the compounds bind to a unique site on the transmembrane domain of the AcrB L protomer, lined by key catalytic residues involved in proton relay. Molecular dynamics simulations suggest that the inhibitors access this binding pocket from the cytoplasm via a channel exclusively present in the AcrB L protomer. Thus, our work unveils a class of allosteric efflux-pump inhibitors that likely act by preventing the functional catalytic cycle of the RND pump. Efflux transporters of the RND family confer resistance to multiple antibiotics in Gram-negative bacteria. Here, the authors identify pyridylpiperazine-based compounds that potentiate antibiotic activity in E. coli through allosteric inhibition of its primary RND transporter.
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21
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Structural and functional analysis of the promiscuous AcrB and AdeB efflux pumps suggests different drug binding mechanisms. Nat Commun 2021; 12:6919. [PMID: 34824229 PMCID: PMC8617272 DOI: 10.1038/s41467-021-27146-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 10/26/2021] [Indexed: 11/08/2022] Open
Abstract
Upon antibiotic stress Gram-negative pathogens deploy resistance-nodulation-cell division-type tripartite efflux pumps. These include a H+/drug antiporter module that recognizes structurally diverse substances, including antibiotics. Here, we show the 3.5 Å structure of subunit AdeB from the Acinetobacter baumannii AdeABC efflux pump solved by single-particle cryo-electron microscopy. The AdeB trimer adopts mainly a resting state with all protomers in a conformation devoid of transport channels or antibiotic binding sites. However, 10% of the protomers adopt a state where three transport channels lead to the closed substrate (deep) binding pocket. A comparison between drug binding of AdeB and Escherichia coli AcrB is made via activity analysis of 20 AdeB variants, selected on basis of side chain interactions with antibiotics observed in the AcrB periplasmic domain X-ray co-structures with fusidic acid (2.3 Å), doxycycline (2.1 Å) and levofloxacin (2.7 Å). AdeABC, compared to AcrAB-TolC, confers higher resistance to E. coli towards polyaromatic compounds and lower resistance towards antibiotic compounds.
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22
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Enantioselectivity of Chiral Derivatives of Xanthones in Virulence Effects of Resistant Bacteria. Pharmaceuticals (Basel) 2021; 14:ph14111141. [PMID: 34832923 PMCID: PMC8623869 DOI: 10.3390/ph14111141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/04/2021] [Accepted: 11/09/2021] [Indexed: 12/04/2022] Open
Abstract
Antimicrobial peptides are one of the lines of defense produced by several hosts in response to bacterial infections. Inspired by them and recent discoveries of xanthones as bacterial efflux pump inhibitors, chiral amides with a xanthone scaffold were planned to be potential antimicrobial adjuvants. The chiral derivatives of xanthones were obtained by peptide coupling reactions between suitable xanthones with enantiomerically pure building blocks, yielding derivatives with high enantiomeric purity. Among 18 compounds investigated for their antimicrobial activity against reference strains of bacteria and fungi, antibacterial activity for the tested strains was not found. Selected compounds were also evaluated for their potential to inhibit bacterial efflux pumps. Compound (R,R)-8 inhibited efflux pumps in the Gram-positive model tested and three compounds, (S,S)-8, (R)-17 and (R,S)-18, displayed the same activity in the Gram-negative strain used. Studies were performed on the inhibition of biofilm formation and quorum-sensing, to which the enantiomeric pair 8 displayed activity for the latter. To gain a better understanding of how the active compounds bind to the efflux pumps, docking studies were performed. Hit compounds were proposed for each activity, and it was shown that enantioselectivity was noticeable and must be considered, as enantiomers displayed differences in activity.
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23
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Identified Seaweed Compound Diphenylmethane Serves as an Efflux Pump Inhibitor in Drug-Resistant Escherichia coli. Antibiotics (Basel) 2021; 10:antibiotics10111378. [PMID: 34827316 PMCID: PMC8614644 DOI: 10.3390/antibiotics10111378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/06/2021] [Accepted: 11/09/2021] [Indexed: 11/17/2022] Open
Abstract
Drug efflux pumps are one of the major elements used by antibiotic-resistant bacteria. Efflux pump inhibitors (EPIs) are potential therapeutic agents for adjunctive therapy, which can restore the activity of antibiotics that are no longer effective against pathogens. This study evaluated the seaweed compound diphenylmethane (DPM) for its EPI activity. The IC50 and modulation results showed that DPM has no antibacterial activity but can potentiate the activity of antibiotics against drug-resistant E. coli. Time-kill studies reported that a combination of DPM and erythromycin exhibited greater inhibitory activity against drug-resistant Escherichia coli. Dye accumulation and dye efflux studies using Hoechst 33342 and ethidium bromide showed that the addition of DPM significantly increased dye accumulation and reduced dye efflux in drug-resistant E. coli, suggesting its interference with dye translocation by an efflux pump. Using MALDI-TOF, it was observed that the addition of DPM could continuously reduce antibiotic efflux in drug-resistant E. coli. Additionally, DPM did not seem to damage the E. coli membranes, and the cell toxicity test showed that it features mild human-cell toxicity. In conclusion, these findings showed that DPM could serve as a potential EPI for drug-resistant E. coli.
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24
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D’Cunha N, Moniruzzaman M, Haynes K, Malloci G, Cooper CJ, Margiotta E, Vargiu AV, Uddin MR, Leus IV, Cao F, Parks JM, Rybenkov VV, Ruggerone P, Zgurskaya HI, Walker JK. Mechanistic Duality of Bacterial Efflux Substrates and Inhibitors: Example of Simple Substituted Cinnamoyl and Naphthyl Amides. ACS Infect Dis 2021; 7:2650-2665. [PMID: 34379382 DOI: 10.1021/acsinfecdis.1c00100] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Antibiotic resistance poses an immediate and growing threat to human health. Multidrug efflux pumps are promising targets for overcoming antibiotic resistance with small-molecule therapeutics. Previously, we identified a diaminoquinoline acrylamide, NSC-33353, as a potent inhibitor of the AcrAB-TolC efflux pump in Escherichia coli. This inhibitor potentiates the antibacterial activities of novobiocin and erythromycin upon binding to the membrane fusion protein AcrA. It is also a substrate for efflux and lacks appreciable intrinsic antibacterial activity of its own in wild-type cells. Here, we have modified the substituents of the cinnamoyl group of NSC-33353, giving rise to analogs that retain the ability to inhibit efflux, lost the features of the efflux substrates, and gained antibacterial activity in wild-type cells. The replacement of the cinnamoyl group with naphthyl isosteres generated compounds that lack antibacterial activity but are both excellent efflux pump inhibitors and substrates. Surprisingly, these inhibitors potentiate the antibacterial activity of novobiocin but not erythromycin. Surface plasmon resonance experiments and molecular docking suggest that the replacement of the cinnamoyl group with naphthyl shifts the affinity of the compounds away from AcrA to the AcrB transporter, making them better efflux substrates and changing their mechanism of inhibition. These results provide new insights into the duality of efflux substrate/inhibitor features in chemical scaffolds that will facilitate the development of new efflux pump inhibitors.
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Affiliation(s)
- Napoleon D’Cunha
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63110, United States
| | - Mohammad Moniruzzaman
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Keith Haynes
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63110, United States
| | - Giuliano Malloci
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Connor J. Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Enrico Margiotta
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Attilio V. Vargiu
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Muhammad R. Uddin
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Inga V. Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Feng Cao
- John Cochran Division, Department of Veteran Affairs Medical Center, St. Louis, Missouri 63106, United States
| | - Jerry M. Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Valentin V. Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - John K. Walker
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63110, United States
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Durães F, Szemerédi N, Kumla D, Pinto M, Kijjoa A, Spengler G, Sousa E. Metabolites from Marine-Derived Fungi as Potential Antimicrobial Adjuvants. Mar Drugs 2021; 19:475. [PMID: 34564137 PMCID: PMC8470461 DOI: 10.3390/md19090475] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/12/2021] [Accepted: 08/21/2021] [Indexed: 12/22/2022] Open
Abstract
Marine-derived fungi constitute an interesting source of bioactive compounds, several of which exhibit antibacterial activity. These acquire special importance, considering that antimicrobial resistance is becoming more widespread. The overexpression of efflux pumps, capable of expelling antimicrobials out of bacterial cells, is one of the most worrisome mechanisms. There has been an ongoing effort to find not only new antimicrobials, but also compounds that can block resistance mechanisms which can be used in combination with approved antimicrobial drugs. In this work, a library of nineteen marine natural products, isolated from marine-derived fungi of the genera Neosartorya and Aspergillus, was evaluated for their potential as bacterial efflux pump inhibitors as well as the antimicrobial-related mechanisms, such as inhibition of biofilm formation and quorum-sensing. Docking studies were performed to predict their efflux pump action. These compounds were also tested for their cytotoxicity in mouse fibroblast cell line NIH/3T3. The results obtained suggest that the marine-derived fungal metabolites are a promising source of compounds with potential to revert antimicrobial resistance and serve as an inspiration for the synthesis of new antimicrobial drugs.
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Affiliation(s)
- Fernando Durães
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (M.P.)
- CIIMAR–Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (D.K.); (A.K.)
| | - Nikoletta Szemerédi
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center, Faculty of Medicine, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary;
| | - Decha Kumla
- CIIMAR–Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (D.K.); (A.K.)
- ICBAS–Institute of Biomedical Sciences Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Madalena Pinto
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (M.P.)
- CIIMAR–Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (D.K.); (A.K.)
| | - Anake Kijjoa
- CIIMAR–Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (D.K.); (A.K.)
- ICBAS–Institute of Biomedical Sciences Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Gabriella Spengler
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center, Faculty of Medicine, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary;
| | - Emília Sousa
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (M.P.)
- CIIMAR–Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (D.K.); (A.K.)
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26
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Dos Santos Barbosa CR, Scherf JR, de Freitas TS, de Menezes IRA, Pereira RLS, Dos Santos JFS, de Jesus SSP, Lopes TP, de Sousa Silveira Z, de Morais Oliveira-Tintino CD, Júnior JPS, Coutinho HDM, Tintino SR, da Cunha FAB. Effect of Carvacrol and Thymol on NorA efflux pump inhibition in multidrug-resistant (MDR) Staphylococcus aureus strains. J Bioenerg Biomembr 2021; 53:489-498. [PMID: 34159523 DOI: 10.1007/s10863-021-09906-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/14/2021] [Indexed: 02/08/2023]
Abstract
Undue exposure to antimicrobials has led to the acquisition and development of sophisticated bacterial resistance mechanisms, such as efflux pumps, which are able to expel or reduce the intracellular concentration of various antibiotics, making them ineffective. Therefore, inhibiting this mechanism is a promising way to minimize the phenomenon of resistance in bacteria. In this sense, the present study sought to evaluate the activity of the Carvacrol (CAR) and Thymol (THY) terpenes as possible Efflux Pump Inhibitors (EPIs), by determining the Minimum Inhibitory Concentration (MIC) and the association of these compounds in subinhibitory concentrations with the antibiotic Norfloxacin and with Ethidium Bromide (EtBr) against strains SA-1199 (wild-type) and SA-1199B (overexpresses NorA) of Staphylococcus aureus. In order to verify the interaction of the terpenes with the NorA efflux protein, an in silico molecular modeling study was carried out. The assays used to obtain the MIC of CAR and THY were performed by broth microdilution, while the Efflux Pump inhibitory test was performed by the MIC modification method of the antibiotic Norfloxacin and EtBr. docking was performed using the Molegro Virtual Docker (MVD) program. The results of the study revealed that CAR and THY have moderate bacterial activity and are capable of reducing the MIC of Norfloxacin antibiotic and EtBr in strains of S. aureus carrying the NorA efflux pump. The docking results showed that these terpenes act as possible competitive NorA inhibitors and can be investigated as adjuvants in combined therapies aimed at reducing antibiotic resistance.
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Affiliation(s)
| | - Jackelyne Roberta Scherf
- Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato, Brazil
| | - Thiago Sampaio de Freitas
- Laboratory of Simulations and Molecular Spectroscopy (Lasemol), Regional University of Cariri-URCA, Crato, Brazil
| | - Irwin Rose Alencar de Menezes
- Laboratory of Pharmacology and Molecular Chemistry (LFQM), Department of Biological Chemistry, Regional University of Cariri-URCA, Crato, Brazil
| | - Raimundo Luiz Silva Pereira
- Laboratory of Simulations and Molecular Spectroscopy (Lasemol), Regional University of Cariri-URCA, Crato, Brazil
| | | | | | - Thais Pereira Lopes
- Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato, Brazil
| | | | | | | | | | - Saulo Relison Tintino
- Laboratory of Microbiology and Molecular Biology (LMBM), Regional University of Cariri-URCA, Crato, Brazil
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27
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Durães F, Palmeira A, Cruz B, Freitas-Silva J, Szemerédi N, Gales L, da Costa PM, Remião F, Silva R, Pinto M, Spengler G, Sousa E. Antimicrobial Activity of a Library of Thioxanthones and Their Potential as Efflux Pump Inhibitors. Pharmaceuticals (Basel) 2021; 14:ph14060572. [PMID: 34203998 PMCID: PMC8232621 DOI: 10.3390/ph14060572] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 12/15/2022] Open
Abstract
The overexpression of efflux pumps is one of the causes of multidrug resistance, which leads to the inefficacy of drugs. This plays a pivotal role in antimicrobial resistance, and the most notable pumps are the AcrAB-TolC system (AcrB belongs to the resistance-nodulation-division family) and the NorA, from the major facilitator superfamily. In bacteria, these structures can also favor virulence and adaptation mechanisms, such as quorum-sensing and the formation of biofilm. In this study, the design and synthesis of a library of thioxanthones as potential efflux pump inhibitors are described. The thioxanthone derivatives were investigated for their antibacterial activity and inhibition of efflux pumps, biofilm formation, and quorum-sensing. The compounds were also studied for their potential to interact with P-glycoprotein (P-gp, ABCB1), an efflux pump present in mammalian cells, and for their cytotoxicity in both mouse fibroblasts and human Caco-2 cells. The results concerning the real-time ethidium bromide accumulation may suggest a potential bacterial efflux pump inhibition, which has not yet been reported for thioxanthones. Moreover, in vitro studies in human cells demonstrated a lack of cytotoxicity for concentrations up to 20 µM in Caco-2 cells, with some derivatives also showing potential for P-gp modulation.
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Affiliation(s)
- Fernando Durães
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (A.P.); (M.P.)
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (J.F.-S.); (P.M.d.C.)
| | - Andreia Palmeira
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (A.P.); (M.P.)
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (J.F.-S.); (P.M.d.C.)
| | - Bárbara Cruz
- UCIBIO-REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; (B.C.); (F.R.); (R.S.)
| | - Joana Freitas-Silva
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (J.F.-S.); (P.M.d.C.)
- ICBAS–Institute of Biomedical Sciences Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Nikoletta Szemerédi
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center and Faculty of Medicine, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary;
| | - Luís Gales
- Department of Molecular Biology, ICBAS–Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal;
- Bioengineering & Synthetic Microbiology, I3S–Instituto de Investigação e Inovação em Saúde, University of Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Paulo Martins da Costa
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (J.F.-S.); (P.M.d.C.)
- ICBAS–Institute of Biomedical Sciences Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Fernando Remião
- UCIBIO-REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; (B.C.); (F.R.); (R.S.)
| | - Renata Silva
- UCIBIO-REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; (B.C.); (F.R.); (R.S.)
| | - Madalena Pinto
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (A.P.); (M.P.)
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (J.F.-S.); (P.M.d.C.)
| | - Gabriella Spengler
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center and Faculty of Medicine, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary;
- Correspondence: (G.S.); (E.S.)
| | - Emília Sousa
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (A.P.); (M.P.)
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; (J.F.-S.); (P.M.d.C.)
- Correspondence: (G.S.); (E.S.)
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28
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Durães F, Resende DISP, Palmeira A, Szemerédi N, Pinto MMM, Spengler G, Sousa E. Xanthones Active against Multidrug Resistance and Virulence Mechanisms of Bacteria. Antibiotics (Basel) 2021; 10:600. [PMID: 34069329 PMCID: PMC8158687 DOI: 10.3390/antibiotics10050600] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/28/2021] [Accepted: 05/17/2021] [Indexed: 02/07/2023] Open
Abstract
The emergence of multidrug and extensively drug-resistant pathogenic bacteria able to resist to the action of a wide range of antibiotics is becoming a growing problem for public health. The search for new compounds with the potential to help in the reversion of bacterial resistance plays an important role in current medicinal chemistry research. Under this scope, bacterial efflux pumps are responsible for the efflux of antimicrobials, and their inhibition could reverse resistance. In this study, the multidrug resistance reversing activity of a series of xanthones was investigated. Firstly, docking studies were performed in the AcrAB-TolC efflux pump and in a homology model of the NorA pump. Then, the effects of twenty xanthone derivatives on bacterial growth were evaluated in Staphylococcus aureus 272123 and in the acrA gene-inactivated mutant Salmonella enterica serovar Typhimurium SL1344 (SE03). Their efflux pump inhibitory properties were assessed using real-time fluorimetry. Assays concerning the activity of these compounds towards the inhibition of biofilm formation and quorum sensing have also been performed. Results showed that a halogenated phenylmethanamine xanthone derivative displayed an interesting profile, as far as efflux pump inhibition and biofilm formation were concerned. To the best of our knowledge, this is the first report of xanthones as potential efflux pump inhibitors.
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Affiliation(s)
- Fernando Durães
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (D.I.S.P.R.); (A.P.); (M.M.M.P.)
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - Diana I. S. P. Resende
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (D.I.S.P.R.); (A.P.); (M.M.M.P.)
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - Andreia Palmeira
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (D.I.S.P.R.); (A.P.); (M.M.M.P.)
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - Nikoletta Szemerédi
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center and Faculty of Medicine, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary;
| | - Madalena M. M. Pinto
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (D.I.S.P.R.); (A.P.); (M.M.M.P.)
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| | - Gabriella Spengler
- Department of Medical Microbiology, Albert Szent-Györgyi Health Center and Faculty of Medicine, University of Szeged, Semmelweis utca 6, 6725 Szeged, Hungary;
| | - Emília Sousa
- Laboratory of Organic and Pharmaceutical Chemistry (LQOF), Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; (F.D.); (D.I.S.P.R.); (A.P.); (M.M.M.P.)
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
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29
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Alav I, Kobylka J, Kuth MS, Pos KM, Picard M, Blair JMA, Bavro VN. Structure, Assembly, and Function of Tripartite Efflux and Type 1 Secretion Systems in Gram-Negative Bacteria. Chem Rev 2021; 121:5479-5596. [PMID: 33909410 PMCID: PMC8277102 DOI: 10.1021/acs.chemrev.1c00055] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Tripartite efflux pumps and the related type 1 secretion systems (T1SSs) in Gram-negative organisms are diverse in function, energization, and structural organization. They form continuous conduits spanning both the inner and the outer membrane and are composed of three principal components-the energized inner membrane transporters (belonging to ABC, RND, and MFS families), the outer membrane factor channel-like proteins, and linking the two, the periplasmic adaptor proteins (PAPs), also known as the membrane fusion proteins (MFPs). In this review we summarize the recent advances in understanding of structural biology, function, and regulation of these systems, highlighting the previously undescribed role of PAPs in providing a common architectural scaffold across diverse families of transporters. Despite being built from a limited number of basic structural domains, these complexes present a staggering variety of architectures. While key insights have been derived from the RND transporter systems, a closer inspection of the operation and structural organization of different tripartite systems reveals unexpected analogies between them, including those formed around MFS- and ATP-driven transporters, suggesting that they operate around basic common principles. Based on that we are proposing a new integrated model of PAP-mediated communication within the conformational cycling of tripartite systems, which could be expanded to other types of assemblies.
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Affiliation(s)
- Ilyas Alav
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Jessica Kobylka
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Miriam S. Kuth
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Klaas M. Pos
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Martin Picard
- Laboratoire
de Biologie Physico-Chimique des Protéines Membranaires, CNRS
UMR 7099, Université de Paris, 75005 Paris, France
- Fondation
Edmond de Rothschild pour le développement de la recherche
Scientifique, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Jessica M. A. Blair
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Vassiliy N. Bavro
- School
of Life Sciences, University of Essex, Colchester, CO4 3SQ United Kingdom
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30
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Moir DT, Opperman TJ, Aron ZD, Bowlin TL. Adjunctive therapy for multidrug-resistant bacterial infections: Type III secretion system and efflux inhibitors. Drug Discov Today 2021; 26:2173-2181. [PMID: 33845218 DOI: 10.1016/j.drudis.2021.03.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/21/2021] [Accepted: 03/31/2021] [Indexed: 10/21/2022]
Abstract
The increasing prevalence of multidrug-resistant (MDR) bacterial infections has created a crucial need for new therapeutics that avoid or minimize existing resistance mechanisms. In this review, we describe the development of novel classes of small-molecule adjunctive agents targeting either a bacterial virulence factor, the Pseudomonas aeruginosa type III secretion system (T3SS), or an intrinsic resistance factor, resistance-nodulation-cell division superfamily (RND) efflux pumps of the Enterobacteriaceae. These agents are designed to be administered with antibacterials to improve their efficacy. T3SS inhibition rescues host innate immune system cells from injection with bacterial toxins, whereas RND efflux pump inhibition increases antibiotic susceptibility, in both cases improving the efficacy of the combined antibacterial.
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31
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Zwama M, Yamaguchi A, Nishino K. Phylogenetic and functional characterisation of the Haemophilus influenzae multidrug efflux pump AcrB. Commun Biol 2019; 2:340. [PMID: 31531401 PMCID: PMC6744504 DOI: 10.1038/s42003-019-0564-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/28/2019] [Indexed: 11/09/2022] Open
Abstract
Multidrug resistance in Gram-negative bacteria can arise by the over-expression of multidrug efflux pumps, which can extrude a wide range of antibiotics. Here we describe the ancestral Haemophilus influenzae efflux pump AcrB (AcrB-Hi). We performed a phylogenetic analysis of hundreds of RND-type transporters. We found that AcrB-Hi is a relatively ancient efflux pump, which nonetheless can export the same range of antibiotics as its evolved colleague from Escherichia coli. AcrB-Hi was not inhibited by the efflux pump inhibitor ABI-PP, and could export bile salts weakly. This points to an environmental adaptation of RND transporters. We also explain the sensitivity of H. influenzae cells to β-lactams and novobiocin by the outer membrane porin OmpP2. This porin counterbalances the AcrB-Hi efflux by leaking the drugs back into the cells. We hypothesise that multidrug recognition by RND-type pumps is not an evolutionarily acquired ability, and has been present since ancient promiscuous transporters.
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Grants
- This work was supported by CREST and the Center of Innovation Program (COI) from the Japan Science and Technology Agency (JST), the Program for the Promotion of Fundamental Studies in Health Sciences of the National Institute of Biomedical Innovation, Grants-in-Aid, Network Joint Research Center for Materials and Devices, Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), Grant-in-Aid Research Activity Start-up (Kakenhi 18H06103) from MEXT, Grant-in-Aid for Scientific Research (B) (Kakenhi 17H03983) from Japan Society for the Promotion of Science (JSPS), and the Japan Agency for Medical Research and Development (AMED).
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Affiliation(s)
- Martijn Zwama
- Department of Biomolecular Science and Regulation, Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 Japan
| | - Akihito Yamaguchi
- Laboratory of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 Japan
| | - Kunihiko Nishino
- Department of Biomolecular Science and Regulation, Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 Japan
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5-Arylideneimidazolones with Amine at Position 3 as Potential Antibiotic Adjuvants against Multidrug Resistant Bacteria. Molecules 2019; 24:molecules24030438. [PMID: 30691112 PMCID: PMC6384991 DOI: 10.3390/molecules24030438] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 01/20/2019] [Accepted: 01/21/2019] [Indexed: 12/30/2022] Open
Abstract
Searching for new chemosensitizers of bacterial multidrug resistance (MDR), chemical modifications of (Z)-5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-4(5H)-one (6) were performed. New compounds (7⁻17), with fused aromatic rings at position 5, were designed and synthesized. Crystallographic X-ray analysis proved that the final compounds (7⁻17) were substituted with tertiary amine-propyl moiety at position 3 and primary amine group at 2 due to intramolecular Dimroth rearrangement. New compounds were evaluated on their antibiotic adjuvant properties in either Gram-positive or Gram-negative bacteria. Efflux pump inhibitor (EPI) properties towards the AcrAB-TolC pump in Enterobacter aerogenes (EA289) were investigated in the real-time efflux (RTE) assay. Docking and molecular dynamics were applied to estimate an interaction of compounds 6⁻17 with penicillin binding protein (PBP2a). In vitro ADME-Tox properties were evaluated for compound 9. Most of the tested compounds reduced significantly (4-32-fold) oxacillin MIC in highly resistant MRSA HEMSA 5 strain. The anthracene-morpholine derivative (16) was the most potent (32-fold reduction). The tested compounds displayed significant EPI properties during RTE assay (37⁻97%). The naphthyl-methylpiperazine derivative 9 showed the most potent "dual action" of both oxacillin adjuvant (MRSA) and EPI (E. aerogenes). Molecular modeling results suggested the allosteric mechanism of action of the imidazolones, which improved binding of oxacillin in the PBP2a active site in MRSA.
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Atzori A, Malviya VN, Malloci G, Dreier J, Pos KM, Vargiu AV, Ruggerone P. Identification and characterization of carbapenem binding sites within the RND-transporter AcrB. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:62-74. [PMID: 30416087 DOI: 10.1016/j.bbamem.2018.10.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 12/11/2022]
Abstract
Understanding the molecular determinants for recognition, binding and transport of antibiotics by multidrug efflux systems is important for basic research and useful for the design of more effective antimicrobial compounds. Imipenem and meropenem are two carbapenems whose antibacterial activity is known to be poorly and strongly affected by MexAB-OprM, the major efflux pump transporter in Pseudomonas aeruginosa. However, not much is known regarding recognition and transport of these compounds by AcrAB-TolC, which is the MexAB-OprM homologue in Escherichia coli and by definition the paradigm model for structural studies on efflux pumps. Prompted by this motivation, we unveiled the molecular details of the interaction of imipenem and meropenem with the transporter AcrB by combining computer simulations with biophysical experiments. Regarding the interaction with the two main substrate binding regions of AcrB, the so-called access and deep binding pockets, molecular dynamics simulations revealed imipenem to be more mobile than meropenem in the former, while comparable mobilities were observed in the latter. This result is in line with isothermal titration calorimetry, differential scanning experiments, and binding free energy calculations, indicating a higher affinity for meropenem than imipenem at the deep binding pocket, while both sharing similar affinities at the access pocket. Our findings rationalize how different physico-chemical properties of compounds reflect on their interactions with AcrB. As such, they constitute precious information to be exploited for the rational design of antibiotics able to evade efflux pumps.
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Affiliation(s)
- Alessio Atzori
- Department of Physics, University of Cagliari, 09042 Monserrato, CA, Italy
| | - Viveka N Malviya
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Giuliano Malloci
- Department of Physics, University of Cagliari, 09042 Monserrato, CA, Italy
| | - Jürg Dreier
- Basilea Pharmaceutica International Ltd., Grenzacherstrasse 487, 4058 Basel, Switzerland
| | - Klaas M Pos
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Attilio V Vargiu
- Department of Physics, University of Cagliari, 09042 Monserrato, CA, Italy
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, 09042 Monserrato, CA, Italy,.
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Hickey SM, Ashton TD, Boer G, Bader CA, Thomas M, Elliott AG, Schmuck C, Yu HY, Li J, Nation RL, Cooper MA, Plush SE, Brooks DA, Pfeffer FM. Norbornane-based cationic antimicrobial peptidomimetics targeting the bacterial membrane. Eur J Med Chem 2018; 160:9-22. [PMID: 30316060 DOI: 10.1016/j.ejmech.2018.09.072] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/14/2018] [Accepted: 09/29/2018] [Indexed: 11/27/2022]
Abstract
The design, synthesis and evaluation of a small series of potent amphiphilic norbornane antibacterial agents has been performed (compound 10 MIC = 0.25 μg/mL against MRSA). Molecular modelling indicates rapid aggregation of this class of antibacterial agent prior to membrane association and insertion. Two fluorescent analogues (compound 29 with 4-amino-naphthalimide and 34 with 4-nitrobenz-2-oxa-1,3-diazole fluorophores) with good activity (MIC = 0.5 μg/mL against MRSA) were also constructed and confocal microscopy studies indicate that the primary site of interaction for this family of compounds is the bacterial membrane.
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Affiliation(s)
- Shane M Hickey
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia.
| | - Trent D Ashton
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Gareth Boer
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Christie A Bader
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Michael Thomas
- Research School of Chemistry, The Australian National University, Acton, ACT, 2601, Australia
| | - Alysha G Elliott
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Carsten Schmuck
- Institute for Organic Chemistry, University of Duisburg-Essen, 45117, Essen, Germany
| | - Heidi Y Yu
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Science, Royal Parade, Parkville, Victoria, 3052, Australia
| | - Jian Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Science, Royal Parade, Parkville, Victoria, 3052, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Science, Royal Parade, Parkville, Victoria, 3052, Australia
| | - Matthew A Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Sally E Plush
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Douglas A Brooks
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Frederick M Pfeffer
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia.
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35
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Bacterial efflux transporters in the limelight. Res Microbiol 2018; 169:349-350. [PMID: 30223033 DOI: 10.1016/j.resmic.2018.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 09/05/2018] [Indexed: 11/20/2022]
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36
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Vargiu AV, Ramaswamy VK, Malloci G, Malvacio I, Atzori A, Ruggerone P. Computer simulations of the activity of RND efflux pumps. Res Microbiol 2018; 169:384-392. [PMID: 29407044 DOI: 10.1016/j.resmic.2017.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/01/2017] [Accepted: 12/05/2017] [Indexed: 12/25/2022]
Abstract
The putative mechanism by which bacterial RND-type multidrug efflux pumps recognize and transport their substrates is a complex and fascinating enigma of structural biology. How a single protein can recognize a huge number of unrelated compounds and transport them through one or just a few mechanisms is an amazing feature not yet completely unveiled. The appearance of cooperativity further complicates the understanding of structure-dynamics-activity relationships in these complex machineries. Experimental techniques may have limited access to the molecular determinants and to the energetics of key processes regulating the activity of these pumps. Computer simulations are a complementary approach that can help unveil these features and inspire new experiments. Here we review recent computational studies that addressed the various molecular processes regulating the activity of RND efflux pumps.
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Affiliation(s)
- Attilio Vittorio Vargiu
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy.
| | - Venkata Krishnan Ramaswamy
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Giuliano Malloci
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Ivana Malvacio
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Alessio Atzori
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, Cittadella Universitaria, S.P. Monserrato-Sestu km 0.700, 09042 Monserrato (CA), Italy.
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37
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Ding F, Songkiatisak P, Cherukuri PK, Huang T, Xu XHN. Size-Dependent Inhibitory Effects of Antibiotic Drug Nanocarriers against Pseudomonas aeruginosa. ACS OMEGA 2018; 3:1231-1243. [PMID: 29399654 PMCID: PMC5793034 DOI: 10.1021/acsomega.7b01956] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 01/12/2018] [Indexed: 05/24/2023]
Abstract
Multidrug membrane transporters (efflux pumps) are responsible for multidrug resistance (MDR) and the low efficacy of therapeutic drugs. Noble metal nanoparticles (NPs) possess a high surface-area-to-volume ratio and size-dependent plasmonic optical properties, enabling them to serve both as imaging probes to study sized-dependent MDR and as potential drug carriers to circumvent MDR and enhance therapeutic efficacy. To this end, in this study, we synthesized three different sizes of silver nanoparticles (Ag NPs), 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm, functionalized their surface with a monolayer of 11-amino-1-undecanethiol (AUT), and covalently conjugated them with antibiotics (ofloxacin, Oflx) to prepare antibiotic drug nanocarriers with conjugation ratios of 8.6 × 102, 9.4 × 103, and 6.5 × 105 Oflx molecules per NP, respectively. We purified and characterized the nanocarriers and developed cell culture medium in which the cells grew normally and the nanocarriers were stable (non-aggregated), to quantitatively study the size, dose, and efflux pump (MexAB-OprM) dependent inhibitory effect of the nanocarriers against two strains of Pseudomonas aeruginosa, WT (normal expression of MexAB-OprM) and ΔABM (deletion of MexAB-OprM). We found that the inhibitory effect of these nanocarriers highly depended on the sizes of NPs, the doses of antibiotic, and the expression of MexAB-OprM. The same amount of Oflx on the largest nanocarriers (92.6 ± 4.4 nm) showed the highest inhibitory effect (the lowest minimal inhibitory concentration) against P. aeruginosa. Surprisingly, the smallest nanocarriers (2.4 ± 0.7 nm) exhibited a lower inhibitory effect than free Oflx. The results suggest that size-dependent multivalent effects, the distribution and localization of Oflx (pharmacodynamics), and the efflux of Oflx all play a role in the inhibitory effects. Control experiments using three sizes of AgMUNH2 NPs (absence of Oflx) showed that these NPs do not exhibit any significant inhibitory activity toward both strains. These new findings demonstrate the need for and possibility of designing optimal sized antibiotic nanocarriers to achieve the highest efficacy against P. aeruginosa.
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