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Johnson RM, Li K, Chen X, Morgan GL, Aubé J, Li B. The Hybrid Antibiotic Thiomarinol A Overcomes Intrinsic Resistance in Escherichia coli Using a Privileged Dithiolopyrrolone Moiety. ACS Infect Dis 2024; 10:582-593. [PMID: 38226592 DOI: 10.1021/acsinfecdis.3c00504] [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] [Indexed: 01/17/2024]
Abstract
An impermeable outer membrane and multidrug efflux pumps work in concert to provide Gram-negative bacteria with intrinsic resistance against many antibiotics. These resistance mechanisms reduce the intracellular concentrations of antibiotics and render them ineffective. The natural product thiomarinol A combines holothin, a dithiolopyrrolone antibiotic, with marinolic acid A, a close analogue of mupirocin. The hybridity of thiomarinol A converts the mupirocin scaffold from inhibiting Gram-positive bacteria to inhibiting both Gram-positive and -negative bacteria. We found that thiomarinol A accumulates significantly more than mupirocin within the Gram-negative bacterium Escherichia coli, likely contributing to its broad-spectrum activity. Antibiotic susceptibility testing of E. coli mutants reveals that thiomarinol A overcomes the intrinsic resistance mechanisms that render mupirocin inactive. Structure-activity relationship studies suggest that the dithiolopyrrolone is a privileged moiety for improving the accumulation and antibiotic activity of the mupirocin scaffold without compromising binding to isoleucyl-tRNA synthetase. These studies also highlight that accumulation is required but not sufficient for antibiotic activity. Our work reveals a role of the dithiolopyrrolone moiety in overcoming intrinsic mupirocin resistance in E. coli and provides a starting point for designing dual-acting and high-accumulating hybrid antibiotics.
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Affiliation(s)
- Rachel M Johnson
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Kelin Li
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Xiaoyan Chen
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Gina L Morgan
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jeffrey Aubé
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Bo Li
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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2
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Li Y, Acharya A, Yang L, Liu J, Tajkhorshid E, Zgurskaya HI, Jackson M, Gumbart JC. Insights into substrate transport and water permeation in the mycobacterial transporter MmpL3. Biophys J 2023; 122:2342-2352. [PMID: 36926696 PMCID: PMC10257117 DOI: 10.1016/j.bpj.2023.03.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/04/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
Mycobacteria, such as Mycobacterium tuberculosis, are characterized by a uniquely thick and waxy cell envelope that consists of two membranes, with a variety of mycolates comprising their outer membrane (OM). The protein Mycobacterial membrane protein Large 3 (MmpL3) is responsible for the transport of a primary OM component, trehalose monomycolate (TMM), from the inner (cytoplasmic) membrane (IM) to the periplasmic space, a process driven by the proton gradient. Although multiple structures of MmpL3 with bound substrates have been solved, the exact pathway(s) for TMM or proton transport remains elusive. Here, employing molecular dynamics simulations we investigate putative pathways for either transport species. We hypothesized that MmpL3 will cycle through similar conformational states as the related transporter AcrB, which we used as targets for modeling the conformation of MmpL3. A continuous water pathway through the transmembrane region was found in one of these states, illustrating a putative pathway for protons. Additional equilibrium simulations revealed that TMM can diffuse from the membrane into a binding pocket in MmpL3 spontaneously. We also found that acetylation of TMM, which is required for transport, makes it more stable within MmpL3's periplasmic cavity compared with the unacetylated form.
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Affiliation(s)
- Yupeng Li
- Theoretical and Computational Biophysics Group, NIH Resource for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Atanu Acharya
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Lixinhao Yang
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry (MB&B), Yale University, New Haven, Connecticut
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Resource for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois; Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
| | - James C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia; School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia.
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3
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Athar M, Gervasoni S, Catte A, Basciu A, Malloci G, Ruggerone P, Vargiu AV. Tripartite efflux pumps of the RND superfamily: what did we learn from computational studies? MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36972322 DOI: 10.1099/mic.0.001307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Bacterial resistance to antibiotics has been long recognized as a priority to address for human health. Among all micro-organisms, the so-called multi-drug resistant (MDR) bacteria, which are resistant to most, if not all drugs in our current arsenal, are particularly worrisome. The World Health Organization has prioritized the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species) pathogens, which include four Gram-negative bacterial species. In these bacteria, active extrusion of antimicrobial compounds out of the cell by means of 'molecular guns' known as efflux pumps is a main determinant of MDR phenotypes. The resistance-nodulation-cell division (RND) superfamily of efflux pumps connecting the inner and outer membrane in Gram-negative bacteria is crucial to the onset of MDR and virulence, as well as biofilm formation. Thus, understanding the molecular basis of the interaction of antibiotics and inhibitors with these pumps is key to the design of more effective therapeutics. With the aim to contribute to this challenge, and complement and inspire experimental research, in silico studies on RND efflux pumps have flourished in recent decades. Here, we review a selection of such investigations addressing the main determinants behind the polyspecificity of these pumps, the mechanisms of substrate recognition, transport and inhibition, as well as the relevance of their assembly for proper functioning, and the role of protein-lipid interactions. The journey will end with a perspective on the role of computer simulations in addressing the challenges posed by these beautifully complex machineries and in supporting the fight against the spread of MDR bacteria.
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Affiliation(s)
- Mohd Athar
- Physics Department, University of Cagliari, Cittadella Universitaria, SP 8 km 0.700, 09042, Monserrato (CA), Italy
| | - Silvia Gervasoni
- Physics Department, University of Cagliari, Cittadella Universitaria, SP 8 km 0.700, 09042, Monserrato (CA), Italy
| | - Andrea Catte
- Physics Department, University of Cagliari, Cittadella Universitaria, SP 8 km 0.700, 09042, Monserrato (CA), Italy
| | - Andrea Basciu
- Physics Department, University of Cagliari, Cittadella Universitaria, SP 8 km 0.700, 09042, Monserrato (CA), Italy
| | - Giuliano Malloci
- Physics Department, University of Cagliari, Cittadella Universitaria, SP 8 km 0.700, 09042, Monserrato (CA), Italy
| | - Paolo Ruggerone
- Physics Department, University of Cagliari, Cittadella Universitaria, SP 8 km 0.700, 09042, Monserrato (CA), Italy
| | - Attilio Vittorio Vargiu
- Physics Department, University of Cagliari, Cittadella Universitaria, SP 8 km 0.700, 09042, Monserrato (CA), Italy
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4
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Manrique PD, López CA, Gnanakaran S, Rybenkov VV, Zgurskaya HI. New understanding of multidrug efflux and permeation in antibiotic resistance, persistence, and heteroresistance. Ann N Y Acad Sci 2023; 1519:46-62. [PMID: 36344198 PMCID: PMC9839546 DOI: 10.1111/nyas.14921] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Antibiotics effective against Gram-negative ESKAPE pathogens are a critical area of unmet need. Infections caused by these pathogens are not only difficult to treat but finding new therapies to overcome Gram-negative resistance is also a challenge. There are not enough antibiotics in development that target the most dangerous pathogens and there are not enough novel drugs in the pipeline. The major obstacle in the antibiotic discovery pipeline is the lack of understanding of how to breach antibiotic permeability barriers of Gram-negative pathogens. These barriers are created by active efflux pumps acting across both the inner and the outer membranes. Overproduction of efflux pumps alone or together with either modification of the outer membrane or antibiotic-inactivating enzymes and target mutations contribute to clinical levels of antibiotics resistance. Recent efforts have generated significant advances in the rationalization of compound efflux and permeation across the cell envelopes of Gram-negative pathogens. Combined with earlier studies and novel mathematical models, these efforts have led to a multilevel understanding of how antibiotics permeate these barriers and how multidrug efflux and permeation contribute to the development of antibiotic resistance and heteroresistance. Here, we discuss the new developments in this area.
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Affiliation(s)
- Pedro D. Manrique
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
- Present address: Physics Department, George Washington University, Washington D.C. 20052, United States
| | - Cesar A. López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
| | - S. Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
| | - Valentin V. Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK 73019, United States
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK 73019, United States
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5
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Barnabas V, Kashyap A, Raja R, Newar K, Rai D, Dixit NM, Mehra S. The Extent of Antimicrobial Resistance Due to Efflux Pump Regulation. ACS Infect Dis 2022; 8:2374-2388. [PMID: 36264222 DOI: 10.1021/acsinfecdis.2c00460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A key mechanism driving antimicrobial resistance (AMR) stems from the ability of bacteria to up-regulate efflux pumps upon exposure to drugs. The resistance gained by this up-regulation is pliable because of the tight regulation of efflux pump levels. This leads to temporary enhancement in survivability of bacteria due to higher efflux pump levels in the presence of antibiotics, which can be reversed when the cells are no longer exposed to the drug. Knowledge of the extent of resistance thus gained would inform intervention strategies aimed at mitigating AMR. Here, we combine mathematical modeling and experiments to quantify the maximum extent of resistance that efflux pump up-regulation can confer via phenotypic induction in the presence of drugs and genotypic abrogation of regulation. Our model describes the dynamics of drug transport in and out of cells coupled with the associated regulation of efflux pump levels and predicts the increase in the minimum inhibitory concentration (MIC) of drugs due to such regulation. To test the model, we measured the uptake and efflux as well as the MIC of the compound ethidium bromide (EtBr), a substrate of the efflux pump LfrA, in wild-type Mycobacterium smegmatis mc2155, as well as in two laboratory-generated strains. Our model captured the observed EtBr levels and MIC fold-changes quantitatively. Further, the model identified key parameters associated with the resulting resistance, variations in which could underlie the extent to which such resistance arises across different drug-bacteria combinations, potentially offering tunable handles to optimize interventions aimed at minimizing AMR.
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Affiliation(s)
- Vinay Barnabas
- Department of Chemical Engineering, Indian Institute of Technology, Mumbai400076, India
| | - Akanksha Kashyap
- Department of Chemical Engineering, Indian Institute of Technology, Mumbai400076, India
| | - Rubesh Raja
- Department of Chemical Engineering, Indian Institute of Science, Bangalore560012, India
| | - Kapil Newar
- Department of Chemical Engineering, Indian Institute of Science, Bangalore560012, India
| | - Deepika Rai
- Department of Chemical Engineering, Indian Institute of Technology, Mumbai400076, India
| | - Narendra M Dixit
- Department of Chemical Engineering, Indian Institute of Science, Bangalore560012, India.,Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore560012, India
| | - Sarika Mehra
- Department of Chemical Engineering, Indian Institute of Technology, Mumbai400076, India
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6
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Miller RD, Iinishi A, Modaresi SM, Yoo BK, Curtis TD, Lariviere PJ, Liang L, Son S, Nicolau S, Bargabos R, Morrissette M, Gates MF, Pitt N, Jakob RP, Rath P, Maier T, Malyutin AG, Kaiser JT, Niles S, Karavas B, Ghiglieri M, Bowman SEJ, Rees DC, Hiller S, Lewis K. Computational identification of a systemic antibiotic for gram-negative bacteria. Nat Microbiol 2022; 7:1661-1672. [PMID: 36163500 PMCID: PMC10155127 DOI: 10.1038/s41564-022-01227-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 08/05/2022] [Indexed: 12/14/2022]
Abstract
Discovery of antibiotics acting against Gram-negative species is uniquely challenging due to their restrictive penetration barrier. BamA, which inserts proteins into the outer membrane, is an attractive target due to its surface location. Darobactins produced by Photorhabdus, a nematode gut microbiome symbiont, target BamA. We reasoned that a computational search for genes only distantly related to the darobactin operon may lead to novel compounds. Following this clue, we identified dynobactin A, a novel peptide antibiotic from Photorhabdus australis containing two unlinked rings. Dynobactin is structurally unrelated to darobactins, but also targets BamA. Based on a BamA-dynobactin co-crystal structure and a BAM-complex-dynobactin cryo-EM structure, we show that dynobactin binds to the BamA lateral gate, uniquely protruding into its β-barrel lumen. Dynobactin showed efficacy in a mouse systemic Escherichia coli infection. This study demonstrates the utility of computational approaches to antibiotic discovery and suggests that dynobactin is a promising lead for drug development.
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Affiliation(s)
- Ryan D Miller
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Akira Iinishi
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | | | - Byung-Kuk Yoo
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Thomas D Curtis
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Patrick J Lariviere
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Libang Liang
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Sangkeun Son
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Samantha Nicolau
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Rachel Bargabos
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Madeleine Morrissette
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Michael F Gates
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Norman Pitt
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | | | | | - Timm Maier
- Biozentrum, University of Basel, Basel, Switzerland
| | - Andrey G Malyutin
- Beckman Institute, California Institute of Technology, Pasadena, CA, USA
| | - Jens T Kaiser
- Beckman Institute, California Institute of Technology, Pasadena, CA, USA
| | - Samantha Niles
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Blake Karavas
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Meghan Ghiglieri
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA
| | - Sarah E J Bowman
- National Crystallization Center, Hauptman-Woodward Medical Research Institute, Buffalo, NY, USA
| | - Douglas C Rees
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | | | - Kim Lewis
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA, USA.
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7
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Łapińska U, Voliotis M, Lee KK, Campey A, Stone MRL, Tuck B, Phetsang W, Zhang B, Tsaneva-Atanasova K, Blaskovich MAT, Pagliara S. Fast bacterial growth reduces antibiotic accumulation and efficacy. eLife 2022; 11:74062. [PMID: 35670099 PMCID: PMC9173744 DOI: 10.7554/elife.74062] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 05/08/2022] [Indexed: 12/11/2022] Open
Abstract
Phenotypic variations between individual microbial cells play a key role in the resistance of microbial pathogens to pharmacotherapies. Nevertheless, little is known about cell individuality in antibiotic accumulation. Here, we hypothesise that phenotypic diversification can be driven by fundamental cell-to-cell differences in drug transport rates. To test this hypothesis, we employed microfluidics-based single-cell microscopy, libraries of fluorescent antibiotic probes and mathematical modelling. This approach allowed us to rapidly identify phenotypic variants that avoid antibiotic accumulation within populations of Escherichia coli, Pseudomonas aeruginosa, Burkholderia cenocepacia, and Staphylococcus aureus. Crucially, we found that fast growing phenotypic variants avoid macrolide accumulation and survive treatment without genetic mutations. These findings are in contrast with the current consensus that cellular dormancy and slow metabolism underlie bacterial survival to antibiotics. Our results also show that fast growing variants display significantly higher expression of ribosomal promoters before drug treatment compared to slow growing variants. Drug-free active ribosomes facilitate essential cellular processes in these fast-growing variants, including efflux that can reduce macrolide accumulation. We used this new knowledge to eradicate variants that displayed low antibiotic accumulation through the chemical manipulation of their outer membrane inspiring new avenues to overcome current antibiotic treatment failures.
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Affiliation(s)
- Urszula Łapińska
- Living Systems Institute, University of ExeterExeterUnited Kingdom
- Biosciences, University of ExeterExeterUnited Kingdom
| | - Margaritis Voliotis
- Living Systems Institute, University of ExeterExeterUnited Kingdom
- Department of Mathematics, University of ExeterExeterUnited Kingdom
| | - Ka Kiu Lee
- Living Systems Institute, University of ExeterExeterUnited Kingdom
- Biosciences, University of ExeterExeterUnited Kingdom
| | - Adrian Campey
- Living Systems Institute, University of ExeterExeterUnited Kingdom
- Biosciences, University of ExeterExeterUnited Kingdom
| | - M Rhia L Stone
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
- Department of Chemistry and Chemical Biology, Rutgers, the State University of New JerseyPiscatawayUnited States
| | - Brandon Tuck
- Living Systems Institute, University of ExeterExeterUnited Kingdom
- Biosciences, University of ExeterExeterUnited Kingdom
| | - Wanida Phetsang
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
| | - Bing Zhang
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
| | - Krasimira Tsaneva-Atanasova
- Living Systems Institute, University of ExeterExeterUnited Kingdom
- Department of Mathematics, University of ExeterExeterUnited Kingdom
- EPSRC Hub for Quantitative Modelling in Healthcare, University of ExeterExeterUnited Kingdom
- Department of Bioinformatics and Mathematical Modelling, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of SciencesSofiaBulgaria
| | - Mark AT Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
| | - Stefano Pagliara
- Living Systems Institute, University of ExeterExeterUnited Kingdom
- Biosciences, University of ExeterExeterUnited Kingdom
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Zhao C, Li C, Wang X, Cao Z, Gao C, Su S, Xue B, Wang S, Qiu Z, Wang J, Shen Z. Monitoring and evaluation of antibiotic resistance genes in three rivers in northeast China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:44148-44161. [PMID: 35122641 DOI: 10.1007/s11356-022-18555-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Antibiotic resistance genes (ARGs) have become an important public health problem. In this study, we used metagenomic sequencing to analyze the composition of ARGs in selected original habitats of northeast China, comprising three different rivers and riverbank soils of the Heilongjiang River, Tumen River, and Yalu River. Twenty types of ARG were detected in the water samples. The major ARGs were multidrug resistance genes, at approximately 0.5 copies/16S rRNA, accounting for 57.5% of the total ARG abundance. The abundance of multidrug, bacitracin, beta-lactam, macrolide-lincosamide-streptogramin, sulfonamide, fosmidomycin, and polymyxin resistance genes covered 96.9% of the total ARG abundance. No significant ecological boundary of ARG diversity was observed. The compositions of the resistance genes in the three rivers were very similar to each other, and 92.1% of ARG subtypes were shared by all water samples. Except for vancomycin resistance genes, almost all ARGs in riverbank soils were detected in the river water. About 31.05% ARGs were carried by Pseudomonas. Opportunistic pathogenic bacteria carrying resistance genes were mainly related to diarrhea and respiratory infections. Multidrug and beta-lactam resistance genes correlated positively with mobile genetic elements (MGEs), indicating a potential risk of diffusion. The composition of ARGs in three different rivers was similar, indicating that climate plays an important role in ARG occurrence. ARG subtypes in river water were almost completely the same as those in riverbank soil. ARGs had no significant geographical distribution characteristics. Many ARGs were carried by human pathogenic bacteria related to diarrhea and respiratory infections, such as Pseudomonas aeruginosa and Aeromonas caviae. In general, our results provide a valuable dataset of river water ARG distribution in northeast China. The related ecological and geographical distribution characteristics should be further explored.
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Affiliation(s)
- Chen Zhao
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Chenyu Li
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xiaoming Wang
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Zhuosong Cao
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
- School of Environmental & Chemical Engineering, Xi'an Polytechnic University, Xi'an, China
| | - Chao Gao
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
- School of Marine Science and Technology, Tianjin University, Tianjin, China
| | - Sicong Su
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Bin Xue
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Shang Wang
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Zhigang Qiu
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Jingfeng Wang
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China.
| | - Zhiqiang Shen
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China.
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9
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Abstract
With the overmining of actinomycetes for compounds acting against Gram-negative pathogens, recent efforts to discover novel antibiotics have been focused on other groups of bacteria. Teixobactin, the first antibiotic without detectable resistance that binds lipid II, comes from an uncultured Eleftheria terra, a betaproteobacterium; odilorhabdins, from Xenorhabdus, are broad-spectrum inhibitors of protein synthesis, and darobactins from Photorhabdus target BamA, the essential chaperone of the outer membrane of Gram-negative bacteria. Xenorhabdus and Photorhabdus are symbionts of the nematode gut microbiome and attractive producers of secondary metabolites. Only small portions of their biosynthetic gene clusters (BGC) are expressed in vitro. To access their silent operons, we first separated extracts from a small library of isolates into fractions, resulting in 200-fold concentrated material, and then screened them for antimicrobial activity. This resulted in a hit with selective activity against Escherichia coli, which we identified as a novel natural product antibiotic, 3′-amino 3′-deoxyguanosine (ADG). Mutants resistant to ADG mapped to gsk and gmk, kinases of guanosine. Biochemical analysis shows that ADG is a prodrug that is converted into an active ADG triphosphate (ADG-TP), a mimic of GTP. ADG incorporates into a growing RNA chain, interrupting transcription, and inhibits cell division, apparently by interfering with the GTPase activity of FtsZ. Gsk of the purine salvage pathway, which is the first kinase in the sequential phosphorylation of ADG, is restricted to E. coli and closely related species, explaining the selectivity of the compound. There are probably numerous targets of ADG-TP among GTP-dependent proteins. The discovery of ADG expands our knowledge of prodrugs, which are rare among natural compounds.
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10
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Kommerein N, Vierengel N, Groß J, Opatz T, Al-Nawas B, Müller-Heupt LK. Antiplanktonic and Antibiofilm Activity of Rheum palmatum against Streptococcus oralis and Porphyromonas gingivalis. Microorganisms 2022; 10:microorganisms10050965. [PMID: 35630409 PMCID: PMC9143743 DOI: 10.3390/microorganisms10050965] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 04/24/2022] [Accepted: 05/01/2022] [Indexed: 01/27/2023] Open
Abstract
Periodontitis and peri-implantitis are inflammatory conditions with a high global prevalence. Oral pathogens such as Porphyromonas gingivalis play a crucial role in the development of dysbiotic biofilms associated with both diseases. The aim of our study was to identify plant-derived substances which mainly inhibit the growth of “disease promoting bacteria”, by comparing the effect of Rheum palmatum root extract against P. gingivalis and the commensal species Streptococcus oralis. Antiplanktonic activity was determined by measuring optical density and metabolic activity. Antibiofilm activity was quantified using metabolic activity assays and live/dead fluorescence staining combined with confocal laser scanning microscopy. At concentrations of 3.9 mg/L, R. palmatum root extract selectively inhibited planktonic growth of the oral pathogen P. gingivalis, while not inhibiting growth of S. oralis. Selective effects also occurred in mature biofilms, as P. gingivalis was significantly more stressed and inhibited than S. oralis. Our studies show that low concentrations of R. palmatum root extract specifically inhibit P. gingivalis growth, and offer a promising approach for the development of a potential topical agent to prevent alterations in the microbiome due to overgrowth of pathogenic P. gingivalis.
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Affiliation(s)
- Nadine Kommerein
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany;
| | - Nina Vierengel
- Department of Chemistry, Johannes Gutenberg-University, Duesbergweg 10–14, 55128 Mainz, Germany; (N.V.); (J.G.); (T.O.)
| | - Jonathan Groß
- Department of Chemistry, Johannes Gutenberg-University, Duesbergweg 10–14, 55128 Mainz, Germany; (N.V.); (J.G.); (T.O.)
| | - Till Opatz
- Department of Chemistry, Johannes Gutenberg-University, Duesbergweg 10–14, 55128 Mainz, Germany; (N.V.); (J.G.); (T.O.)
| | - Bilal Al-Nawas
- Department of Oral- and Maxillofacial Surgery, University Medical Center Mainz, Augustusplatz 2, 55131 Mainz, Germany;
| | - Lena Katharina Müller-Heupt
- Department of Oral- and Maxillofacial Surgery, University Medical Center Mainz, Augustusplatz 2, 55131 Mainz, Germany;
- Correspondence: ; Tel.: +49-6131-175086
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11
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Nag A, Mehra S. Involvement of the SCO3366 efflux pump from S. coelicolor in rifampicin resistance and its regulation by a TetR regulator. Appl Microbiol Biotechnol 2022; 106:2175-2190. [PMID: 35194656 DOI: 10.1007/s00253-022-11837-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 02/05/2022] [Accepted: 02/12/2022] [Indexed: 11/26/2022]
Abstract
Overexpression of efflux pumps represents a key mechanism of resistance in bacteria. Soil bacteria such as Streptomyces harbour a vast array of efflux genes that are transcriptionally silent under laboratory conditions. However, dissemination of many of these genes into clinical pathogens via horizontal gene transfer results in conferring resistance to multiple drugs. In this study, we have identified the role of a MFS transporter, SCO3366 from Streptomyces coelicolor, in governing multidrug resistance. Overexpression and knockout studies revealed that SCO3366 provides resistance to several structurally unrelated drugs including ciprofloxacin, chloramphenicol, rifampicin and EtBr, with rifampicin being the major substrate. Beyond multidrug resistance, SCO3366 was efficient in providing tolerance towards oxidative stress. A combinatorial mechanism of increased oxidative stress tolerance decreased intracellular drug levels and decreased permeability act synergistically to provide resistance towards rifampicin. Shedding light on the regulation of SCO3366, we find the pump to be directly regulated by the TetR regulator SCO3367 in a negative manner and the repression was found to be relieved in presence of different compounds recognized as substrates of SCO3366. KEY POINTS: • First reported rifampicin efflux pump in Streptomyces coelicolor • Resistance to rifampicin is the result of a synergistic action of increased efflux with increased oxidative stress tolerance and decreased permeability, which can potentially arise in clinically relevant bacteria • SCO3366-SCO3367 to be a novel system that operates to protect the bacteria under varied environmental stress conditions.
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Affiliation(s)
- Ankita Nag
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Sarika Mehra
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
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12
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Sun L, Sun L, Li X, Hu X, Wang X, Nie T, Zhang Y, You X. A Novel Tigecycline Adjuvant ML-7 Reverses the Susceptibility of Tigecycline-Resistant Klebsiella pneumoniae. Front Cell Infect Microbiol 2022; 11:809542. [PMID: 35071055 PMCID: PMC8766836 DOI: 10.3389/fcimb.2021.809542] [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: 11/05/2021] [Accepted: 12/09/2021] [Indexed: 12/01/2022] Open
Abstract
The increasing incidence of tigecycline resistance undoubtedly constitutes a serious threat to global public health. The combination therapies had become the indispensable strategy against this threat. Herein, 11 clinical tigecycline-resistant Klebsiella pneumoniae which mainly has mutations in ramR, acrR, or macB were collected for tigecycline adjuvant screening. Interestingly, ML-7 hydrochloride (ML-7) dramatically potentiated tigecycline activity. We further picked up five analogs of ML-7 and evaluated their synergistic activities with tigecycline by using checkerboard assay. The results revealed that ML-7 showed certain synergy with tigecycline, while other analogs exerted attenuated synergistic effects among tigecycline-resistant isolates. Thus, ML-7 was selected for further investigation. The results from growth curves showed that ML-7 combined with tigecycline could completely inhibit the growth of bacteria, and the time-kill analysis revealed that the combination exhibited synergistic bactericidal activities for tigecycline-resistant isolates during 24 h. The ethidium bromide (EtBr) efflux assay demonstrated that ML-7 could inhibit the functions of efflux pump. Besides, ML-7 disrupted the proton motive force (PMF) via increasing ΔpH, which in turn lead to the inhibition of the functions of efflux pump, reduction of intracellular ATP levels, as well as accumulation of ROS. All of which promoted the death of bacteria. And further transcriptomic analysis revealed that genes related to the mechanism of ML-7 mainly enriched in ABC transporters. Taken together, these results revealed the potential of ML-7 as a novel tigecycline adjuvant to circumvent tigecycline-resistant Klebsiella pneumoniae.
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Affiliation(s)
- Lilan Sun
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Lang Sun
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xue Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xinxin Hu
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xiukun Wang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Tongying Nie
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Youwen Zhang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xuefu You
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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13
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Diversity and biological activity of fungal endophytes of Zingiber officinale Rosc. with emphasis on Aspergillus terreus as a biocontrol agent of its leaf spot. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2021.102234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Jurasz J, Bagiński M, Czub J, Wieczór M. Molecular mechanism of proton-coupled ligand translocation by the bacterial efflux pump EmrE. PLoS Comput Biol 2021; 17:e1009454. [PMID: 34613958 PMCID: PMC8523053 DOI: 10.1371/journal.pcbi.1009454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/18/2021] [Accepted: 09/15/2021] [Indexed: 11/18/2022] Open
Abstract
The current surge in bacterial multi-drug resistance (MDR) is one of the largest challenges to public health, threatening to render ineffective many therapies we rely on for treatment of serious infections. Understanding different factors that contribute to MDR is hence crucial from the global “one health” perspective. In this contribution, we focus on the prototypical broad-selectivity proton-coupled antiporter EmrE, one of the smallest known ligand transporters that confers resistance to aromatic cations in a number of clinically relevant species. As an asymmetric homodimer undergoing an “alternating access” protomer-swap conformational change, it serves as a model for the mechanistic understanding of more complex drug transporters. Here, we present a free energy and solvent accessibility analysis that indicates the presence of two complementary ligand translocation pathways that remain operative in a broad range of conditions. Our simulations show a previously undescribed desolvated apo state and anticorrelated accessibility in the ligand-bound state, explaining on a structural level why EmrE does not disrupt the pH gradient through futile proton transfer. By comparing the behavior of a number of model charged and/or aromatic ligands, we also explain the origin of selectivity of EmrE towards a broad class of aromatic cations. Finally, we explore unbiased pathways of ligand entry and exit to identify correlated structural changes implicated in ligand binding and release, as well as characterize key intermediates of occupancy changes. EmrE is a prototypical bacterial multidrug transporter (MDR) that confers resistance to drugs and antiseptics. Due to its structural simplicity, its mechanism of ligand recognition and translocation are relevant for a wide class of transporters. This proton-coupled antiport expels aromatic cations from the cytoplasm using the alternating access mechanism, achieving impressive levels of efficiency and robustness. Our protonation-specific free energy profiles, Grotthuss wire analyses and equilibrium simulations show how a deceivingly simple system can exchange ions with robustness and precision, hopefully inspiring rational efforts to design new MDR inhibitors.
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Affiliation(s)
- Jakub Jurasz
- Department of Pharmaceutical Technology and Biochemistry, Gdansk University of Technology, Gdansk, Poland
| | - Maciej Bagiński
- Department of Pharmaceutical Technology and Biochemistry, Gdansk University of Technology, Gdansk, Poland
- BioTechMed Center, Gdansk University of Technology, Gdansk, Poland
| | - Jacek Czub
- BioTechMed Center, Gdansk University of Technology, Gdansk, Poland
- Department of Physical Chemistry, Gdansk University of Technology, Gdansk, Poland
| | - Miłosz Wieczór
- Department of Physical Chemistry, Gdansk University of Technology, Gdansk, Poland
- Molecular Modeling and Bioinformatics Group, IRB Barcelona, Barcelona, Spain
- * E-mail:
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15
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Lo CC, Liao WY, Chou MC, Wu YY, Yeh TH, Lo HR. Overexpression of Resistance-Nodulation-Division Efflux Pump Genes Contributes to Multidrug Resistance in Aeromonas hydrophila Clinical Isolates. Microb Drug Resist 2021; 28:153-160. [PMID: 34609911 DOI: 10.1089/mdr.2021.0084] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Aeromonas hydrophila is a Gram-negative bacterium that is a critical causative agent of infections in fish and is occasionally responsible for human infections following contact with contaminated water or food. Currently, the extensive use of antibiotics in clinical practice has led to increased number of isolates of multidrug-resistant (MDR) Aeromonas and has posed a serious public health challenge. The efflux pump system is a critical mechanism of antibiotic resistance in most Gram-negative bacteria. However, the role of resistance-nodulation-division (RND)-type efflux pumps in MDR A. hydrophila is not fully understood. We aimed to evaluate the contribution of the RND efflux pump system to MDR A. hydrophila clinical isolates. PCR results indicated a considerable variation in the presence of RND efflux pump genes in clinical isolates compared to that of the environmental reference strain ATCC7966T. Compared to non-MDR clinical isolates, the expression levels of three putative RND efflux pump genes, AHA0021, AHA1320, and AheB, were significantly elevated in MDR strains. The minimal inhibitory concentrations of piperacillin/tazobactam, imipenem, erythromycin, and polymyxin B were significantly reduced by phenylalanine-arginine β-naphthylamide (PAβN), further supporting the contribution of the RND efflux system in MDR A. hydrophila. We provided evidence supporting the contribution of the RND efflux system to multidrug resistance in A. hydrophila clinical isolates. Further studies are warranted to elucidate the detailed mechanisms that confer intrinsic resistance to antimicrobials in A. hydrophila.
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Affiliation(s)
- Chung-Cheng Lo
- Department of Internal Medicine, Kaohsiung Veterans General Hospital Pingtung Branch, Pingtung, Taiwan
| | - Wan-Yu Liao
- Department of Medical Laboratory Science and Biotechnology, Fooyin University, Kaohsiung, Taiwan
| | - Miao-Chen Chou
- Department of Medical Laboratory Science and Biotechnology, Fooyin University, Kaohsiung, Taiwan
| | - Yu-Yi Wu
- Department of Medical Laboratory Science and Biotechnology, Fooyin University, Kaohsiung, Taiwan
| | - Tzu-Hui Yeh
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital Pingtung Branch, Pingtung, Taiwan
| | - Horng-Ren Lo
- Department of Medical Laboratory Science and Biotechnology, Fooyin University, Kaohsiung, Taiwan
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16
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Kell DB. The Transporter-Mediated Cellular Uptake and Efflux of Pharmaceutical Drugs and Biotechnology Products: How and Why Phospholipid Bilayer Transport Is Negligible in Real Biomembranes. Molecules 2021; 26:5629. [PMID: 34577099 PMCID: PMC8470029 DOI: 10.3390/molecules26185629] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/03/2021] [Accepted: 09/14/2021] [Indexed: 12/12/2022] Open
Abstract
Over the years, my colleagues and I have come to realise that the likelihood of pharmaceutical drugs being able to diffuse through whatever unhindered phospholipid bilayer may exist in intact biological membranes in vivo is vanishingly low. This is because (i) most real biomembranes are mostly protein, not lipid, (ii) unlike purely lipid bilayers that can form transient aqueous channels, the high concentrations of proteins serve to stop such activity, (iii) natural evolution long ago selected against transport methods that just let any undesirable products enter a cell, (iv) transporters have now been identified for all kinds of molecules (even water) that were once thought not to require them, (v) many experiments show a massive variation in the uptake of drugs between different cells, tissues, and organisms, that cannot be explained if lipid bilayer transport is significant or if efflux were the only differentiator, and (vi) many experiments that manipulate the expression level of individual transporters as an independent variable demonstrate their role in drug and nutrient uptake (including in cytotoxicity or adverse drug reactions). This makes such transporters valuable both as a means of targeting drugs (not least anti-infectives) to selected cells or tissues and also as drug targets. The same considerations apply to the exploitation of substrate uptake and product efflux transporters in biotechnology. We are also beginning to recognise that transporters are more promiscuous, and antiporter activity is much more widespread, than had been realised, and that such processes are adaptive (i.e., were selected by natural evolution). The purpose of the present review is to summarise the above, and to rehearse and update readers on recent developments. These developments lead us to retain and indeed to strengthen our contention that for transmembrane pharmaceutical drug transport "phospholipid bilayer transport is negligible".
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Affiliation(s)
- Douglas B. Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St, Liverpool L69 7ZB, UK;
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs Lyngby, Denmark
- Mellizyme Biotechnology Ltd., IC1, Liverpool Science Park, Mount Pleasant, Liverpool L3 5TF, UK
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17
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Alegun O, Pandeya A, Cui J, Ojo I, Wei Y. Donnan Potential across the Outer Membrane of Gram-Negative Bacteria and Its Effect on the Permeability of Antibiotics. Antibiotics (Basel) 2021; 10:antibiotics10060701. [PMID: 34208097 PMCID: PMC8230823 DOI: 10.3390/antibiotics10060701] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
The cell envelope structure of Gram-negative bacteria is unique, composed of two lipid bilayer membranes and an aqueous periplasmic space sandwiched in between. The outer membrane constitutes an extra barrier to limit the exchange of molecules between the cells and the exterior environment. Donnan potential is a membrane potential across the outer membrane, resulted from the selective permeability of the membrane, which plays a pivotal role in the permeability of many antibiotics. In this review, we discussed factors that affect the intensity of the Donnan potential, including the osmotic strength and pH of the external media, the osmoregulated periplasmic glucans trapped in the periplasmic space, and the displacement of cell surface charges. The focus of our discussion is the impact of Donnan potential on the cellular permeability of selected antibiotics including fluoroquinolones, tetracyclines, β-lactams, and trimethoprim.
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Affiliation(s)
| | | | | | | | - Yinan Wei
- Correspondence: ; Tel.: +1-8592577085
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18
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Souabni H, Batista Dos Santos W, Cece Q, Catoire LJ, Puvanendran D, Bavro VN, Picard M. Quantitative real-time analysis of the efflux by the MacAB-TolC tripartite efflux pump clarifies the role of ATP hydrolysis within mechanotransmission mechanism. Commun Biol 2021; 4:493. [PMID: 33888866 PMCID: PMC8062640 DOI: 10.1038/s42003-021-01997-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 03/18/2021] [Indexed: 02/07/2023] Open
Abstract
Tripartite efflux pumps built around ATP-binding cassette (ABC) transporters are membrane protein machineries that perform vectorial export of a large variety of drugs and virulence factors from Gram negative bacteria, using ATP-hydrolysis as energy source. Determining the number of ATP molecules consumed per transport cycle is essential to understanding the efficiency of substrate transport. Using a reconstituted pump in a membrane mimic environment, we show that MacAB-TolC from Escherichia coli couples substrate transport to ATP-hydrolysis with high efficiency. Contrary to the predictions of the currently prevailing "molecular bellows" model of MacB-operation, which assigns the power stroke to the ATP-binding by the nucleotide binding domains of the transporter, by utilizing a novel assay, we report clear synchronization of the substrate transfer with ATP-hydrolysis, suggesting that at least some of the power stroke for the substrate efflux is provided by ATP-hydrolysis. Our findings narrow down the window for energy consumption step that results in substrate transition into the TolC-channel, expanding the current understanding of the efflux cycle of the MacB-based tripartite assemblies. Based on that we propose a modified model of the MacB cycle within the context of tripartite complex assembly.
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Affiliation(s)
- Hager Souabni
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS UMR 7099, Université de Paris, Paris, France
- Fondation Edmond de Rothschild pour le développement de la recherche Scientifique, Institut de Biologie Physico-Chimique, Paris, France
| | - William Batista Dos Santos
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS UMR 7099, Université de Paris, Paris, France
- Fondation Edmond de Rothschild pour le développement de la recherche Scientifique, Institut de Biologie Physico-Chimique, Paris, France
| | - Quentin Cece
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS UMR 7099, Université de Paris, Paris, France
- Fondation Edmond de Rothschild pour le développement de la recherche Scientifique, Institut de Biologie Physico-Chimique, Paris, France
| | - Laurent J Catoire
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS UMR 7099, Université de Paris, Paris, France
- Fondation Edmond de Rothschild pour le développement de la recherche Scientifique, Institut de Biologie Physico-Chimique, Paris, France
| | - Dhenesh Puvanendran
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS UMR 7099, Université de Paris, Paris, France
- Fondation Edmond de Rothschild pour le développement de la recherche Scientifique, Institut de Biologie Physico-Chimique, Paris, France
- Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY, USA
| | | | - Martin Picard
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS UMR 7099, Université de Paris, Paris, France.
- Fondation Edmond de Rothschild pour le développement de la recherche Scientifique, Institut de Biologie Physico-Chimique, Paris, France.
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19
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Henderson PJF, Maher C, Elbourne LDH, Eijkelkamp BA, Paulsen IT, Hassan KA. Physiological Functions of Bacterial "Multidrug" Efflux Pumps. Chem Rev 2021; 121:5417-5478. [PMID: 33761243 DOI: 10.1021/acs.chemrev.0c01226] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacterial multidrug efflux pumps have come to prominence in human and veterinary pathogenesis because they help bacteria protect themselves against the antimicrobials used to overcome their infections. However, it is increasingly realized that many, probably most, such pumps have physiological roles that are distinct from protection of bacteria against antimicrobials administered by humans. Here we undertake a broad survey of the proteins involved, allied to detailed examples of their evolution, energetics, structures, chemical recognition, and molecular mechanisms, together with the experimental strategies that enable rapid and economical progress in understanding their true physiological roles. Once these roles are established, the knowledge can be harnessed to design more effective drugs, improve existing microbial production of drugs for clinical practice and of feedstocks for commercial exploitation, and even develop more sustainable biological processes that avoid, for example, utilization of petroleum.
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Affiliation(s)
- Peter J F Henderson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Claire Maher
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia
| | - Liam D H Elbourne
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Bart A Eijkelkamp
- College of Science and Engineering, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Ian T Paulsen
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
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20
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Zgurskaya HI, Walker JK, Parks JM, Rybenkov VV. Multidrug Efflux Pumps and the Two-Faced Janus of Substrates and Inhibitors. Acc Chem Res 2021; 54:930-939. [PMID: 33539084 PMCID: PMC8208102 DOI: 10.1021/acs.accounts.0c00843] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antibiotics are miracle drugs that can cure infectious bacterial diseases. However, their utility is challenged by antibiotic-resistant bacteria emerging in clinics and straining modern medicine and our ways of life. Certain bacteria such as Gram-negative (Gram(-)) and Mycobacteriales species are intrinsically resistant to most clinical antibiotics and can further gain multidrug resistance through mutations and plasmid acquisition. These species stand out by the presence of an additional external lipidic membrane, the outer membrane (OM), that is composed of unique glycolipids. Although formidable, the OM is a passive permeability barrier that can reduce penetration of antibiotics but cannot affect intracellular steady-state concentrations of drugs. The two-membrane envelopes are further reinforced by active efflux transporters that expel antibiotics from cells against their concentration gradients. The major mechanism of antibiotic resistance in Gram(-) pathogens is the active efflux of drugs, which acts synergistically with the low permeability barrier of the OM and other mutational and plasmid-borne mechanisms of antibiotic resistance.The synergy between active efflux and slow uptake offers Gram(-) bacteria an impressive degree of protection from potentially harmful chemicals, but it is also their Achilles heel. Kinetic studies have revealed that even small changes in the efficiency of either of the two factors can have dramatic effects on drug penetration into the cell. In line with these expectations, two major approaches to overcome this antibiotic resistance mechanism are currently being explored: (1) facilitation of antibiotic penetration across the outer membranes and (2) avoidance and inhibition of clinically relevant multidrug efflux pumps. Herein we summarize the progress in the latter approach with a focus on efflux pumps from the resistance-nodulation-division (RND) superfamily. The ability to export various substrates across the OM at the expense of the proton-motive force acting on the inner membrane and the engagement of accessory proteins for their functions are the major mechanistic advantages of these pumps. Both the RND transporters and their accessory proteins are being targeted in the discovery of efflux pump inhibitors, which in combination with antibiotics can potentiate antibacterial activities. We discuss intriguing relationships between substrates and inhibitors of efflux pumps, as these two types of ligands face similar barriers and binding sites in the transporters and accessory proteins and both types of activities often occur with the same chemical scaffold. Several distinct chemical classes of efflux inhibitors have been discovered that are as structurally diverse as the substrates of efflux pumps. Recent mechanistic insights, both empirical and computational, have led to the identification of features that distinguish OM permeators and efflux pump avoiders as well as efflux inhibitors from substrates. These findings suggest a path forward for optimizing the OM permeation and efflux-inhibitory activities in antibiotics and other chemically diverse compounds.
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Affiliation(s)
- Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - John K Walker
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104, 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, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
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21
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Salcedo-Sora JE, Jindal S, O'Hagan S, Kell DB. A palette of fluorophores that are differentially accumulated by wild-type and mutant strains of Escherichia coli: surrogate ligands for profiling bacterial membrane transporters. MICROBIOLOGY (READING, ENGLAND) 2021; 167:001016. [PMID: 33406033 PMCID: PMC8131027 DOI: 10.1099/mic.0.001016] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/15/2020] [Indexed: 12/12/2022]
Abstract
Our previous work demonstrated that two commonly used fluorescent dyes that were accumulated by wild-type Escherichia coli MG1655 were differentially transported in single-gene knockout strains, and also that they might be used as surrogates in flow cytometric transporter assays. We summarize the desirable properties of such stains, and here survey 143 candidate dyes. We eventually triage them (on the basis of signal, accumulation levels and cost) to a palette of 39 commercially available and affordable fluorophores that are accumulated significantly by wild-type cells of the 'Keio' strain BW25113, as measured flow cytometrically. Cheminformatic analyses indicate both their similarities and their (much more considerable) structural differences. We describe the effects of pH and of the efflux pump inhibitor chlorpromazine on the accumulation of the dyes. Even the 'wild-type' MG1655 and BW25113 strains can differ significantly in their ability to take up such dyes. We illustrate the highly differential uptake of our dyes into strains with particular lesions in, or overexpressed levels of, three particular transporters or transporter components (yhjV, yihN and tolC). The relatively small collection of dyes described offers a rapid, inexpensive, convenient and informative approach to the assessment of microbial physiology and phenotyping of membrane transporter function.
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Affiliation(s)
- Jesus Enrique Salcedo-Sora
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
| | - Srijan Jindal
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
| | - Steve O'Hagan
- Department of Chemistry and Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester M1 7DN, UK
| | - Douglas B. Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs Lyngby, Denmark
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22
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Zhao S, Adamiak JW, Bonifay V, Mehla J, Zgurskaya HI, Tan DS. Defining new chemical space for drug penetration into Gram-negative bacteria. Nat Chem Biol 2020; 16:1293-1302. [PMID: 33199906 PMCID: PMC7897441 DOI: 10.1038/s41589-020-00674-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 09/11/2020] [Indexed: 12/24/2022]
Abstract
We live in the era of antibiotic resistance, and this problem will progressively worsen if no new solutions emerge. In particular, Gram-negative pathogens present both biological and chemical challenges that hinder the discovery of new antibacterial drugs. First, these bacteria are protected from a variety of structurally diverse drugs by a low-permeability barrier composed of two membranes with distinct permeability properties, in addition to active drug efflux, making this cell envelope impermeable to most compounds. Second, chemical libraries currently used in drug discovery contain few compounds that can penetrate Gram-negative bacteria. As a result of these challenges, intensive screening campaigns have led to few successes, highlighting the need for new approaches to identify regions of chemical space that are specifically relevant to antibacterial drug discovery. Herein we provide an overview of emerging insights into this problem and outline a general approach to addressing it using prospective analysis of chemical libraries for the ability of compounds to accumulate in Gram-negative bacteria. The overall goal is to develop robust cheminformatic tools to predict Gram-negative permeation and efflux, which can then be used to guide medicinal chemistry campaigns and the design of antibacterial discovery libraries.
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Affiliation(s)
- Shibin Zhao
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Justyna W Adamiak
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Vincent Bonifay
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Jitender Mehla
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA.
| | - Derek S Tan
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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Leus IV, Adamiak J, Trinh AN, Smith RD, Smith L, Richardson S, Ernst RK, Zgurskaya HI. Inactivation of AdeABC and AdeIJK efflux pumps elicits specific nonoverlapping transcriptional and phenotypic responses in Acinetobacter baumannii. Mol Microbiol 2020; 114:1049-1065. [PMID: 32858760 DOI: 10.1111/mmi.14594] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/17/2020] [Indexed: 12/24/2022]
Abstract
Multidrug resistant (MDR) strains of Acinetobacter baumannii present a serious clinical challenge. The development of antibiotic resistance in this species is enabled by efflux pumps of the Resistance-Nodulation-Division (RND) superfamily of proteins creating an efficient permeability barrier for antibiotics. At least three RND pumps, AdeABC, AdeIJK, and AdeFGH are encoded in the A. baumannii genome and are reported to contribute to antibiotic resistance in clinical isolates. In this study, we analyzed the contributions of AdeABC and AdeIJK in antibiotic resistance and growth physiology of the two MDR strains, AYE and AB5075. We found that not only the two pumps have nonoverlapping substrate specificities, their inactivation leads to specific nonoverlapping changes in gene expression as determined by RNA sequencing and confirmed by gene knockouts and growth phenotypes. Our results suggest that inactivation of AdeIJK elicits broader changes in the abundances of mRNAs and this response is modified in the absence of AdeB. In contrast, inactivation of AdeB leads to a focused cellular response, which is not sensitive to the activity of AdeIJK. We identified additional efflux pumps and transcriptional regulators that contribute to MDR phenotype of clinical A. baumannii isolates.
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Affiliation(s)
- Inga V Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Justyna Adamiak
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Anhthu N Trinh
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Richard D Smith
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, Baltimore, MD, USA
| | - Lauren Smith
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Sophie Richardson
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, Baltimore, MD, USA
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, USA
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25
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Moreira LG, Almeida AM, Camacho SA, Estevão BM, Oliveira ON, Aoki PHB. Chain Cleavage of Bioinspired Bacterial Membranes Photoinduced by Eosin Decyl Ester. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:9578-9585. [PMID: 32672975 DOI: 10.1021/acs.langmuir.0c01600] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Photodynamic therapy (PDT) is promising for bacterial inactivation since cellular internalization of photosensitizers (PS) is not crucial for the treatment effectiveness. Photoinduced damage in the lipid envelope may already induce microbial inactivation, which requires PS capable of easily penetrating into the membrane. Herein, we report on the insertion of the PS eosin decyl ester (EosDec) into Langmuir films of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DOPG), and cardiolipin (CLP) used as mimetic systems of bacterial membranes. Surface pressure isotherms and polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS) indicated that the hydrophobic nature of EosDec favored deeper penetration in all the phospholipid monolayers. The incorporation of EosDec led to monolayer expansion, especially in the anionic DOPG and CLP owing to repulsive electrostatic interactions, and induced disorder in the lipid chains. Light irradiation of DOPE, DOPG, and CLP monolayers containing EosDec increased the rate of material loss to the subphase, which is attributed to cleavage of lipid chains triggered by contact-dependent reactions between excited states of EosDec and lipid unsaturations. The latter is key for membrane permeabilization and efficiency in microbial inactivation.
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Affiliation(s)
- Lucas G Moreira
- School of Sciences, Humanities and Languages, São Paulo State University (UNESP), Assis, SP 19806-900, Brazil
| | - Alexandre M Almeida
- School of Sciences, Humanities and Languages, São Paulo State University (UNESP), Assis, SP 19806-900, Brazil
| | - Sabrina A Camacho
- School of Sciences, Humanities and Languages, São Paulo State University (UNESP), Assis, SP 19806-900, Brazil
- IFSC, São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, SP 13566-590, Brazil
| | - Bianca M Estevão
- IFSC, São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, SP 13566-590, Brazil
- Department of Chemistry, State University of Maringá (UEM), Maringá, PR 87020-900, Brazil
| | - Osvaldo N Oliveira
- IFSC, São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, SP 13566-590, Brazil
| | - Pedro H B Aoki
- School of Sciences, Humanities and Languages, São Paulo State University (UNESP), Assis, SP 19806-900, Brazil
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Honeycutt JD, Wenner N, Li Y, Brewer SM, Massis LM, Brubaker SW, Chairatana P, Owen SV, Canals R, Hinton JCD, Monack DM. Genetic variation in the MacAB-TolC efflux pump influences pathogenesis of invasive Salmonella isolates from Africa. PLoS Pathog 2020; 16:e1008763. [PMID: 32834002 PMCID: PMC7446830 DOI: 10.1371/journal.ppat.1008763] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/30/2020] [Indexed: 01/23/2023] Open
Abstract
The various sub-species of Salmonella enterica cause a range of disease in human hosts. The human-adapted Salmonella enterica serovar Typhi enters the gastrointestinal tract and invades systemic sites to cause enteric (typhoid) fever. In contrast, most non-typhoidal serovars of Salmonella are primarily restricted to gut tissues. Across Africa, invasive non-typhoidal Salmonella (iNTS) have emerged with an ability to spread beyond the gastrointestinal tract and cause systemic bloodstream infections with increased morbidity and mortality. To investigate this evolution in pathogenesis, we compared the genomes of African iNTS isolates with other Salmonella enterica serovar Typhimurium and identified several macA and macB gene variants unique to African iNTS. MacAB forms a tripartite efflux pump with TolC and is implicated in Salmonella pathogenesis. We show that macAB transcription is upregulated during macrophage infection and after antimicrobial peptide exposure, with macAB transcription being supported by the PhoP/Q two-component system. Constitutive expression of macAB improves survival of Salmonella in the presence of the antimicrobial peptide C18G. Furthermore, these macAB variants affect replication in macrophages and influence fitness during colonization of the murine gastrointestinal tract. Importantly, the infection outcome resulting from these macAB variants depends upon both the Salmonella Typhimurium genetic background and the host gene Nramp1, an important determinant of innate resistance to intracellular bacterial infection. The variations we have identified in the MacAB-TolC efflux pump in African iNTS may reflect evolution within human host populations that are compromised in their ability to clear intracellular Salmonella infections.
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Affiliation(s)
- Jared D. Honeycutt
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Nicolas Wenner
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Yan Li
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Susan M. Brewer
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Liliana M. Massis
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Sky W. Brubaker
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Phoom Chairatana
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Siân V. Owen
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Rocío Canals
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Jay C. D. Hinton
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Denise M. Monack
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
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Zhang D, Hu Y, Zhu Q, Huang J, Chen Y. Proteomic interrogation of antibiotic resistance and persistence in Escherichia coli - progress and potential for medical research. Expert Rev Proteomics 2020; 17:393-409. [PMID: 32567419 DOI: 10.1080/14789450.2020.1784731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Introduction Escherichia coli strains possess two survival strategies to endure lethal antibiotic exposure including antibiotic resistance and persistence, in which persistence can contribute to the emergence of antibiotic resistance and increasing the risk of multidrug resistance. Using high-throughput proteomics for the comprehensive understanding of mechanisms of antibiotic resistance and persistence is an effective strategy for development of target-based anti-bacterial therapies. Areas covered In this review, we summarize a comprehensive proteomic perspective of antibiotic resistance and persistence in E. coli, and overview of anti-antibiotic resistance and anti-persister molecules and strategies for the development of potential therapies. Expert opinion Proteomics allows us to globally identify the critical proteins and pathways involved in antibiotic resistance and persistence. Advancements in methodologies of proteomics and multi-omic strategies are required to overcome the limitations of proteomics and better understand mechanisms of antibiotic resistance and persistence in E. coli, and to open the possibility for identification of new targets for alternative strategies in therapeutics.
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Affiliation(s)
- Danfeng Zhang
- School of Biological Science and Biotechnology, Minnan Normal University , Zhangzhou, China
| | - Yuanqing Hu
- School of Biological Science and Biotechnology, Minnan Normal University , Zhangzhou, China
| | - Qiuqiang Zhu
- School of Biological Science and Biotechnology, Minnan Normal University , Zhangzhou, China
| | - Jiafu Huang
- School of Biological Science and Biotechnology, Minnan Normal University , Zhangzhou, China.,Engineering Technological Center of Mushroom Industry , Zhangzhou, China
| | - Yiyun Chen
- School of Biological Science and Biotechnology, Minnan Normal University , Zhangzhou, China
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Mansbach RA, Leus IV, Mehla J, Lopez CA, Walker JK, Rybenkov VV, Hengartner NW, Zgurskaya HI, Gnanakaran S. Machine Learning Algorithm Identifies an Antibiotic Vocabulary for Permeating Gram-Negative Bacteria. J Chem Inf Model 2020; 60:2838-2847. [PMID: 32453589 DOI: 10.1021/acs.jcim.0c00352] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Drug discovery faces a crisis. The industry has used up the "obvious" space in which to find novel drugs for biomedical applications, and productivity is declining. One strategy to combat this is rational approaches to expand the search space without relying on chemical intuition, to avoid rediscovery of similar spaces. In this work, we present proof of concept of an approach to rationally identify a "chemical vocabulary" related to a specific drug activity of interest without employing known rules. We focus on the pressing concern of multidrug resistance in Pseudomonas aeruginosa by searching for submolecules that promote compound entry into this bacterium. By synergizing theory, computation, and experiment, we validate our approach, explain the molecular mechanism behind identified fragments promoting compound entry, and select candidate compounds from an external library that display good permeation ability.
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Affiliation(s)
- Rachael A Mansbach
- Department of Theoretical Biology and Biophysics, Los Alamos National Lab, MS-K710, P.O. Box 1663, Los Alamos, New Mexico 87545-0001, United States
| | - Inga V Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, SLSRC, Rm 1000, Norman, Oklahoma 73019-5251, United States
| | - Jitender Mehla
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, SLSRC, Rm 1000, Norman, Oklahoma 73019-5251, United States
| | - Cesar A Lopez
- Department of Theoretical Biology and Biophysics, Los Alamos National Lab, MS-K710, P.O. Box 1663, Los Alamos, New Mexico 87545-0001, United States
| | - John K Walker
- Pharmacology and Physiological Science, School of Medicine, Saint Louis University, Schwitalla Hall, Room M362, St. Louis, Missouri 63104, United States
| | - Valentin V Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, SLSRC, Rm 1000, Norman, Oklahoma 73019-5251, United States
| | - Nicolas W Hengartner
- Department of Theoretical Biology and Biophysics, Los Alamos National Lab, MS-K710, P.O. Box 1663, Los Alamos, New Mexico 87545-0001, United States
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, SLSRC, Rm 1000, Norman, Oklahoma 73019-5251, United States
| | - S Gnanakaran
- Department of Theoretical Biology and Biophysics, Los Alamos National Lab, MS-K710, P.O. Box 1663, Los Alamos, New Mexico 87545-0001, United States
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29
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The Role of Bacterial Membrane Vesicles in the Dissemination of Antibiotic Resistance and as Promising Carriers for Therapeutic Agent Delivery. Microorganisms 2020; 8:microorganisms8050670. [PMID: 32380740 PMCID: PMC7284617 DOI: 10.3390/microorganisms8050670] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/25/2020] [Accepted: 05/02/2020] [Indexed: 12/11/2022] Open
Abstract
The rapid emergence and spread of antibiotic-resistant bacteria continues to be an issue difficult to deal with, especially in the clinical, animal husbandry, and food fields. The occurrence of multidrug-resistant bacteria renders treatment with antibiotics ineffective. Therefore, the development of new therapeutic methods is a worthwhile research endeavor in treating infections caused by antibiotic-resistant bacteria. Recently, bacterial membrane vesicles (BMVs) have been investigated as a possible approach to drug delivery and vaccine development. The BMVs are released by both pathogenic and non-pathogenic Gram-positive and Gram-negative bacteria, containing various components originating from the cytoplasm and the cell envelope. The BMVs are able to transform bacteria with genes that encode enzymes such as proteases, glycosidases, and peptidases, resulting in the enhanced antibiotic resistance in bacteria. The BMVs can increase the resistance of bacteria to antibiotics. However, the biogenesis and functions of BMVs are not fully understood in association with the bacterial pathogenesis. Therefore, this review aims to discuss BMV-associated antibiotic resistance and BMV-based therapeutic interventions.
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30
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Saha P, Sikdar S, Krishnamoorthy G, Zgurskaya HI, Rybenkov VV. Drug Permeation against Efflux by Two Transporters. ACS Infect Dis 2020; 6:747-758. [PMID: 32039579 DOI: 10.1021/acsinfecdis.9b00510] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The development of new antibiotics against Gram-negative bacteria is hampered by the powerful protective properties of their cell envelope. This envelope consists of two membranes augmented by efflux transporters, which act in synergy to restrict cellular access to a broad range of chemical compounds. Recently, a kinetic model of this system has been constructed. The model revealed a complex, nonlinear behavior of the system, complete with a bifurcation, and matched very well to experimental uptake data. Here, we expand the model to include multiple transporters and apply it to an experimental analysis of antibiotic accumulation in wild-type and efflux-deficient Escherichia coli. We show that transporters acting across the inner and outer membranes have synergistic effects with each other. In contrast, transporters acting across the same membrane are additive as a rule but can be synergistic under special circumstances owing to a bifurcation controlled by the barrier constant. With respect to ethidium bromide, the inner membrane transporter MdfA was synergistic to the TolC-dependent efflux across the outer membrane. The agreement between the model and drug accumulation was very good across a range of tested drug concentrations and strains. However, antibiotic susceptibilities related only qualitatively to the accumulation of the drugs or predictions of the model and could be fit to the model only if additional assumptions were made about the physiological consequences of prolonged cell exposure to the drugs. Thus, the constructed model correctly predicts transmembrane permeation of various compounds and potentially their intracellular activity.
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Affiliation(s)
- Paramita Saha
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Samapan Sikdar
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Ganesh Krishnamoorthy
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Valentin V. Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
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Zgurskaya HI, Rybenkov VV. Permeability barriers of Gram-negative pathogens. Ann N Y Acad Sci 2020; 1459:5-18. [PMID: 31165502 PMCID: PMC6940542 DOI: 10.1111/nyas.14134] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/06/2019] [Accepted: 05/13/2019] [Indexed: 12/13/2022]
Abstract
Most clinical antibiotics do not have efficacy against Gram-negative pathogens, mainly because these cells are protected by the permeability barrier comprising the two membranes with active efflux. The emergence of multidrug-resistant Gram-negative strains threatens the utility even of last resort therapeutic treatments. Significant efforts at different levels of resolution are currently focused on finding a solution to this nonpermeation problem and developing new approaches to the optimization of drug activities against multidrug-resistant pathogens. The exceptional efficiency of the Gram-negative permeability barrier is the result of a complex interplay between the two opposing fluxes of drugs across the two membranes. In this review, we describe the current state of understanding of the problem and the recent advances in theoretical and empirical approaches to characterization of drug permeation and active efflux in Gram-negative bacteria.
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Affiliation(s)
- Helen I Zgurskaya
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma
| | - Valentin V Rybenkov
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma
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Cunrath O, Meinel DM, Maturana P, Fanous J, Buyck JM, Saint Auguste P, Seth-Smith HMB, Körner J, Dehio C, Trebosc V, Kemmer C, Neher R, Egli A, Bumann D. Quantitative contribution of efflux to multi-drug resistance of clinical Escherichia coli and Pseudomonas aeruginosa strains. EBioMedicine 2019; 41:479-487. [PMID: 30852163 PMCID: PMC6443642 DOI: 10.1016/j.ebiom.2019.02.061] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 02/22/2019] [Accepted: 02/28/2019] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Efflux pumps mediate antimicrobial resistance in several WHO critical priority bacterial pathogens. However, most available data come from laboratory strains. The quantitative relevance of efflux in more relevant clinical isolates remains largely unknown. METHODS We developed a versatile method for genetic engineering in multi-drug resistant (MDR) bacteria, and used this method to delete tolC and specific antibiotic-resistance genes in 18 representative MDR clinical E. coli isolates. We determined efflux activity and minimal inhibitory concentrations for a diverse set of clinically relevant antibiotics in these mutants. We also deleted oprM in MDR P. aeruginosa strains and determined the impact on antibiotic susceptibility. FINDINGS tolC deletion abolished detectable efflux activity in 15 out of 18 tested E. coli strains, and modulated antibiotic susceptibility in many strains. However, all mutant strains retained MDR status, primarily because of other, antibiotic-specific resistance genes. Deletion of oprM altered antibiotic susceptibility in a fraction of clinical P. aeruginosa isolates. INTERPRETATION Efflux modulates antibiotic resistance in clinical MDR isolates of E. coli and P. aeruginosa. However, when other antimicrobial-resistance mechanisms are present, inhibition of MDR efflux pumps alone is often not sufficient to restore full susceptibility even for antibiotics with a dramatic impact of efflux in laboratory strains. We propose that development of novel antibiotics should include target validation in clinical MDR isolates. FUND: Innovative Medicines Initiative of European Union and EFPIA, Schweizerischer Nationalfonds, Swiss National Research Program 72, EU Marie Skłodowska-Curie program. The funders played no role in design, data collection, data analysis, interpretation, writing of the report, and in the decision to submit the paper for publication.
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Affiliation(s)
| | - Dominik M Meinel
- Clinical Microbiology, University Hospital Basel, Switzerland; Applied Microbiology Research, Department of Biomedicine, University of Basel, CH-4056 Basel, Switzerland
| | | | | | | | | | - Helena M B Seth-Smith
- Clinical Microbiology, University Hospital Basel, Switzerland; Applied Microbiology Research, Department of Biomedicine, University of Basel, CH-4056 Basel, Switzerland
| | - Jonas Körner
- Biozentrum, University Hospital Basel, Switzerland
| | | | - Vincent Trebosc
- BioVersys AG, Hochbergerstrasse 60C, Technology Park, 4057 Basel, Switzerland
| | - Christian Kemmer
- BioVersys AG, Hochbergerstrasse 60C, Technology Park, 4057 Basel, Switzerland
| | | | - Adrian Egli
- Clinical Microbiology, University Hospital Basel, Switzerland; Applied Microbiology Research, Department of Biomedicine, University of Basel, CH-4056 Basel, Switzerland
| | - Dirk Bumann
- Biozentrum, University Hospital Basel, Switzerland.
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Abstract
The transport of small molecules across membranes is essential for the import of nutrients and other energy sources into the cell and, for the export of waste and other potentially harmful byproducts out of the cell. While hydrophobic molecules are permeable to membranes, ions and other small polar molecules require transport via specialized membrane transport proteins . The two major classes of membrane transport proteins are transporters and channels. With our focus here on porins-major class of non-specific diffusion channel proteins , we will highlight some recent structural biology reports and functional assays that have substantially contributed to our understanding of the mechanism that mediates uptake of small molecules, including antibiotics, across the outer membrane of Enterobacteriaceae . We will also review advances in the regulation of porin expression and porin biogenesis and discuss these pathways as new therapeutic targets.
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Affiliation(s)
- Muriel Masi
- UMR_MD1, Inserm U1261, IRBA, Membranes et Cibles Thérapeutiques, Facultés de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | | | - Jean-Marie Pagès
- UMR_MD1, Inserm U1261, IRBA, Membranes et Cibles Thérapeutiques, Facultés de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
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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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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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Reens AL, Crooks AL, Su CC, Nagy TA, Reens DL, Podoll JD, Edwards ME, Yu EW, Detweiler CS. A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. PLoS Pathog 2018; 14:e1007115. [PMID: 29879224 PMCID: PMC6007937 DOI: 10.1371/journal.ppat.1007115] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/19/2018] [Accepted: 05/21/2018] [Indexed: 12/20/2022] Open
Abstract
Bacterial efflux pumps transport small molecules from the cytoplasm or periplasm outside the cell. Efflux pump activity is typically increased in multi-drug resistant (MDR) pathogens; chemicals that inhibit efflux pumps may have potential for antibiotic development. Using an in-cell screen, we identified three efflux pump modulators (EPMs) from a drug diversity library. The screening platform uses macrophages infected with the human Gram-negative pathogen Salmonella enterica (Salmonella) to identify small molecules that prevent bacterial replication or survival within the host environment. A secondary screen for hit compounds that increase the accumulation of an efflux pump substrate, Hoechst 33342, identified three small molecules with activity comparable to the known efflux pump inhibitor PAβN (Phe-Arg β-naphthylamide). The three putative EPMs demonstrated significant antibacterial activity against Salmonella within primary and cell culture macrophages and within a human epithelial cell line. Unlike traditional antibiotics, the three compounds did not inhibit bacterial growth in standard microbiological media. The three compounds prevented energy-dependent efflux pump activity in Salmonella and bound the AcrB subunit of the AcrAB-TolC efflux system with KDs in the micromolar range. Moreover, the EPMs display antibacterial synergy with antimicrobial peptides, a class of host innate immune defense molecules present in body fluids and cells. The EPMs also had synergistic activity with antibiotics exported by AcrAB-TolC in broth and in macrophages and inhibited efflux pump activity in MDR Gram-negative ESKAPE clinical isolates. Thus, an in-cell screening approach identified EPMs that synergize with innate immunity to kill bacteria and have potential for development as adjuvants to antibiotics.
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Affiliation(s)
- Abigail L. Reens
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Amy L. Crooks
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve, Cleveland OH, United States of America
| | - Toni A. Nagy
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - David L. Reens
- Department of Physics, University of Colorado Boulder, Boulder, CO, United States of America
- JILA, National Institutes of Standards and Technology and University of Colorado Boulder, Boulder, CO, United States of America
| | - Jessica D. Podoll
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Madeline E. Edwards
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve, Cleveland OH, United States of America
| | - Corrella S. Detweiler
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
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