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Yang J, Zhang L, He X, Gou X, Zong Z, Luo Y. In vitro and in vivo enhancement effect of glabridin on the antibacterial activity of colistin, against multidrug resistant Escherichia coli strains. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024; 130:155732. [PMID: 38776738 DOI: 10.1016/j.phymed.2024.155732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 04/19/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND The increase in antimicrobial resistance leads to complications in treatments, prolonged hospitalization, and increased mortality. Glabridin (GLA) is a hydroxyisoflavan from Glycyrrhiza glabra L. that exhibits multiple pharmacological activities. Colistin (COL), a last-resort antibiotic, is increasingly being used in clinic against Gram-negative bacteria. Previous reports have shown that GLA is able to sensitize first line antibiotics such as norfloxacin and vancomycin on Staphylococcus aureus, implying that the use of GLA as an antibiotic adjuvant is a promising strategy for addressing the issue of drug resistance. However, the adjuvant effect on other antibiotics, especially COL, on Gram-negative bacteria such as Escherichia coli has not been studied. PURPOSE The objective of our study was to investigate the targets of GLA and the synergistic effect of GLA and COL in E. coli, and to provide further evidence for the use of GLA as an antibiotic adjuvant to alleviate the problem of drug resistance. METHODS We first investigated the interaction between GLA and enoyl-acyl carrier protein reductase, also called "FabI", through enzyme inhibition assay, differential scanning fluorimetry, isothermal titration calorimetry and molecular docking assay. We tested the transmembrane capacity of GLA on its own and combined it with several antibiotics. The antimicrobial activities of GLA and COL were evaluated against six different susceptible and resistant E. coli in vitro. Their interactions were analyzed using checkerboard assay, time-kill curve and CompuSyn software. A series of sensitivity tests was conducted in E. coli overexpressing the fabI gene. The development of COL resistance in the presence of GLA was tested. The antimicrobial efficacy of GLA and COL in a mouse model of urinary tract infection was assessed. The anti-biofilm effects of GLA and COL were investigated. RESULTS In this study, enzyme kinetic analysis and thermal analysis provided evidence for the interaction between GLA and FabI in E. coli. GLA enhanced the antimicrobial effect of COL and synergistically suppressed six different susceptible and resistant E. coli with COL. Overexpression experiments showed that targeted inhibition of FabI was a key mechanism by which GLA synergistically enhanced COL activity. The combination of GLA and COL slowed the development of COL resistance in E. coli. Combined GLA and COL treatment significantly reduced bacterial load and mitigated urinary tract injury in a mouse model of E. coli urinary tract infection. Additionally, GLA + COL inhibited the formation and eradication of biofilms and the synthesis of curli. CONCLUSION Our findings indicate that GLA synergistically enhances antimicrobial activities of COL by targeting inhibition of FabI in E. coli. GLA is expected to continue to be developed as an antibiotic adjuvant to address drug resistance issues.
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Affiliation(s)
- Jiaxing Yang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Laiying Zhang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xinlian He
- Laboratory of Human Diseases and Immunotherapy, and State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xupeng Gou
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zhiyong Zong
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Youfu Luo
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.
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2
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Rodríguez-Robles E, Müller D, Künzl T, Nemat SJ, Edelmann MP, Srivastava P, Louis D, Groaz E, Tiefenbacher K, Roberts TM, Herdewijn P, Marlière P, Panke S. Rational design of a bacterial import system for new-to-nature molecules. Metab Eng 2024; 85:26-34. [PMID: 38802041 DOI: 10.1016/j.ymben.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 04/27/2024] [Accepted: 05/23/2024] [Indexed: 05/29/2024]
Abstract
Integration of novel compounds into biological processes holds significant potential for modifying or expanding existing cellular functions. However, the cellular uptake of these compounds is often hindered by selectively permeable membranes. We present a novel bacterial transport system that has been rationally designed to address this challenge. Our approach utilizes a highly promiscuous sulfonate membrane transporter, which allows the passage of cargo molecules attached as amides to a sulfobutanoate transport vector molecule into the cytoplasm of the cell. These cargoes can then be unloaded from the sulfobutanoyl amides using an engineered variant of the enzyme γ-glutamyl transferase, which hydrolyzes the amide bond and releases the cargo molecule within the cell. Here, we provide evidence for the broad substrate specificity of both components of the system by evaluating a panel of structurally diverse sulfobutanoyl amides. Furthermore, we successfully implement the synthetic uptake system in vivo and showcase its functionality by importing an impermeant non-canonical amino acid.
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Affiliation(s)
- Emilio Rodríguez-Robles
- Bioprocess Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - David Müller
- Bioprocess Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Tilmann Künzl
- Bioprocess Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Suren J Nemat
- Department of Chemistry, University of Basel, Basel, Switzerland
| | - Martin Peter Edelmann
- Bioprocess Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Puneet Srivastava
- Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Elisabetta Groaz
- Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Tania Michelle Roberts
- Bioprocess Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Piet Herdewijn
- Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Sven Panke
- Bioprocess Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland.
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3
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Dash R, Holsinger KA, Chordia MD, Gh. MS, Pires MM. Bioluminescence-Based Determination of Cytosolic Accumulation of Antibiotics in Escherichia coli. ACS Infect Dis 2024; 10:1602-1611. [PMID: 38592927 PMCID: PMC11091882 DOI: 10.1021/acsinfecdis.3c00684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/11/2024]
Abstract
Antibiotic resistance is an alarming public health concern that affects millions of individuals across the globe each year. A major challenge in the development of effective antibiotics lies in their limited ability to permeate cells, noting that numerous susceptible antibiotic targets reside within the bacterial cytosol. Consequently, improving the cellular permeability is often a key consideration during antibiotic development, underscoring the need for reliable methods to assess the permeability of molecules across cellular membranes. Currently, methods used to measure permeability often fail to discriminate between the arrival within the cytoplasm and the overall association of molecules with the cell. Additionally, these techniques typically possess throughput limitations. In this work, we describe a luciferase-based assay designed for assessing the permeability of molecules in the cytosolic compartment of Gram-negative bacteria. Our findings demonstrate a robust system that can elucidate the kinetics of intracellular antibiotic accumulation in live bacterial cells in real time.
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Affiliation(s)
- Rachita Dash
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Kadie A. Holsinger
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Mahendra D. Chordia
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Mohammad Sharifian Gh.
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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4
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Poulsen BE, Warrier T, Barkho S, Bagnall J, Romano KP, White T, Yu X, Kawate T, Nguyen PH, Raines K, Ferrara K, Golas A, Fitzgerald M, Boeszoermenyi A, Kaushik V, Serrano-Wu M, Shoresh N, Hung DT. "Multiplexed screen identifies a Pseudomonas aeruginosa -specific small molecule targeting the outer membrane protein OprH and its interaction with LPS". BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.16.585348. [PMID: 38559044 PMCID: PMC10980007 DOI: 10.1101/2024.03.16.585348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The surge of antimicrobial resistance threatens efficacy of current antibiotics, particularly against Pseudomonas aeruginosa , a highly resistant gram-negative pathogen. The asymmetric outer membrane (OM) of P. aeruginosa combined with its array of efflux pumps provide a barrier to xenobiotic accumulation, thus making antibiotic discovery challenging. We adapted PROSPECT 1 , a target-based, whole-cell screening strategy, to discover small molecule probes that kill P. aeruginosa mutants depleted for essential proteins localized at the OM. We identified BRD1401, a small molecule that has specific activity against a P. aeruginosa mutant depleted for the essential lipoprotein, OprL. Genetic and chemical biological studies identified that BRD1401 acts by targeting the OM β-barrel protein OprH to disrupt its interaction with LPS and increase membrane fluidity. Studies with BRD1401 also revealed an interaction between OprL and OprH, directly linking the OM with peptidoglycan. Thus, a whole-cell, multiplexed screen can identify species-specific chemical probes to reveal novel pathogen biology.
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5
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Wang Z, Guo S, Cai Y, Yang Q, Wang Y, Yu X, Sun W, Qiu S, Li X, Guo Y, Xie Y, Zhang A, Zheng S. Decoding active compounds and molecular targets of herbal medicine by high-throughput metabolomics technology: A systematic review. Bioorg Chem 2024; 144:107090. [PMID: 38218070 DOI: 10.1016/j.bioorg.2023.107090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 12/19/2023] [Accepted: 12/31/2023] [Indexed: 01/15/2024]
Abstract
Clinical experiences of herbal medicine (HM) have been used to treat a variety of human intractable diseases. As the treatment of diseases using HM is characterized by multi-components and multi-targets, it is difficult to determine the bio-active components, explore the molecular targets and reveal the mechanisms of action. Metabolomics is frequently used to characterize the effect of external disturbances on organisms because of its unique advantages on detecting changes in endogenous small-molecule metabolites. Its systematicity and integrity are consistent with the effective characteristics of HM. After HM intervention, metabolomics can accurately capture and describe the behavior of endogenous metabolites under the disturbance of functional compounds, which will be used to decode the bioactive ingredients of HM and expound the molecular targets. Metabolomics can provide an approach for explaining HM, addressing unclear clinical efficacy and undefined mechanisms of action. In this review, the metabolomics strategy and its applications in HM are systematically introduced, which offers valuable insights for metabolomics methods to characterizing the pharmacological effects and molecular targets of HM.
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Affiliation(s)
- Zhibo Wang
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; Graduate School, Heilongjiang University of Chinese Medicine, Harbin 150040, China
| | - Sifan Guo
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China
| | - Ying Cai
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; Graduate School, Heilongjiang University of Chinese Medicine, Harbin 150040, China
| | - Qiang Yang
- Graduate School, Heilongjiang University of Chinese Medicine, Harbin 150040, China
| | - Yan Wang
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China
| | - Xiaodan Yu
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China
| | - Wanying Sun
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China
| | - Shi Qiu
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China.
| | - Xiancai Li
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Guangzhou 510650, China.
| | - Yu Guo
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China.
| | - Yiqiang Xie
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China.
| | - Aihua Zhang
- Scientific Experiment Center, Hainan General Hospital, International Advanced Functional Omics Platform, International Joint Research Center on Traditional Chinese and Modern Medicine, Key Laboratory of Tropical Cardiovascular Diseases Research of Hainan Province, Hainan Engineering Research Center for Biological Sample Resources of Major Diseases, Hainan Medical University, Xueyuan Road 3, Haikou 571199, China; Graduate School, Heilongjiang University of Chinese Medicine, Harbin 150040, China.
| | - Shaojiang Zheng
- Medical Research Center of The First Affiliated Hospital, Hainan Women and Children Medical Center, Key Laboratory of Emergency and Trauma of Ministry of Education, Hainan Medical University, Haikou 571199, China.
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6
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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 PMCID: PMC11235417 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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7
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Squire S, Sebghati S, Hammond MC. Cytoplasmic Accumulation and Permeability of Antibiotics in Gram Positive and Gram Negative Bacteria Visualized in Real-Time via a Fluorogenic Tagging Strategy. ACS Chem Biol 2024; 19:3-8. [PMID: 38096425 PMCID: PMC10805102 DOI: 10.1021/acschembio.3c00510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/06/2023] [Accepted: 12/08/2023] [Indexed: 01/23/2024]
Abstract
In this study, we describe the first real-time live cell assay for compound accumulation and permeability in both Gram positive and Gram negative bacteria. The assay utilizes a novel fluorogenic tagging strategy that permits direct visualization of compound accumulation dynamics in the cytoplasm of live cells, unobscured by washing or other processing steps. Quantitative differences could be reproducibly measured by flow cytometry at compound concentrations below the limit of detection for MS-based approaches. We establish the fluorogenic assay in E. coli and B. subtilis and compare the intracellular accumulation of two antibiotics, ciprofloxacin and ampicillin, with related pharmacophores in these bacteria.
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Affiliation(s)
- Scott
O. Squire
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Cell & Genome Science, University of Utah, Salt Lake
City, Utah 84112, United States
| | - Sepehr Sebghati
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Cell & Genome Science, University of Utah, Salt Lake
City, Utah 84112, United States
| | - Ming C. Hammond
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Cell & Genome Science, University of Utah, Salt Lake
City, Utah 84112, United States
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8
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Phelps GA, Cheramie MN, Fernando DM, Selchow P, Meyer CJ, Waidyarachchi SL, Dharuman S, Liu J, Meuli M, Molin MD, Killam BY, Murphy PA, Reeve SM, Wilt LA, Anderson SM, Yang L, Lee RB, Temrikar ZH, Lukka PB, Meibohm B, Polikanov YS, Hobbie SN, Böttger EC, Sander P, Lee RE. Development of 2nd generation aminomethyl spectinomycins that overcome native efflux in Mycobacterium abscessus. Proc Natl Acad Sci U S A 2024; 121:e2314101120. [PMID: 38165935 PMCID: PMC10786304 DOI: 10.1073/pnas.2314101120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/11/2023] [Indexed: 01/04/2024] Open
Abstract
Mycobacterium abscessus (Mab), a nontuberculous mycobacterial (NTM) species, is an emerging pathogen with high intrinsic drug resistance. Current standard-of-care therapy results in poor outcomes, demonstrating the urgent need to develop effective antimycobacterial regimens. Through synthetic modification of spectinomycin (SPC), we have identified a distinct structural subclass of N-ethylene linked aminomethyl SPCs (eAmSPCs) that are up to 64-fold more potent against Mab over the parent SPC. Mechanism of action and crystallography studies demonstrate that the eAmSPCs display a mode of ribosomal inhibition consistent with SPC. However, they exert their increased antimicrobial activity through enhanced accumulation, largely by circumventing efflux mechanisms. The N-ethylene linkage within this series plays a critical role in avoiding TetV-mediated efflux, as lead eAmSPC 2593 displays a mere fourfold susceptibility improvement against Mab ΔtetV, in contrast to the 64-fold increase for SPC. Even a minor shortening of the linkage by a single carbon, akin to 1st generation AmSPC 1950, results in a substantial increase in MICs and a 16-fold rise in susceptibility against Mab ΔtetV. These shifts suggest that longer linkages might modify the kinetics of drug expulsion by TetV, ultimately shifting the equilibrium towards heightened intracellular concentrations and enhanced antimicrobial efficacy. Furthermore, lead eAmSPCs were also shown to synergize with various classes of anti-Mab antibiotics and retain activity against clinical isolates and other mycobacterial strains. Encouraging pharmacokinetic profiles coupled with robust efficacy in Mab murine infection models suggest that eAmSPCs hold the potential to be developed into treatments for Mab and other NTM infections.
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Affiliation(s)
- Gregory A. Phelps
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
- Graduate School of Biomedical Sciences, St. Jude Children’s Research Hospital, Memphis, TN38103
| | - Martin N. Cheramie
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Dinesh M. Fernando
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Petra Selchow
- Institute of Medical Microbiology, University of Zurich, ZurichCH-8006, Switzerland
| | - Christopher J. Meyer
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Samanthi L. Waidyarachchi
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Suresh Dharuman
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Jiuyu Liu
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Michael Meuli
- Institute of Medical Microbiology, University of Zurich, ZurichCH-8006, Switzerland
- National Reference Center for Mycobacteria, ZurichCH-8006, Switzerland
| | - Michael Dal Molin
- Institute of Medical Microbiology, University of Zurich, ZurichCH-8006, Switzerland
| | - Benjamin Y. Killam
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL60607
| | - Patricia A. Murphy
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Stephanie M. Reeve
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Laura A. Wilt
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Shelby M. Anderson
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Lei Yang
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Robin B. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
| | - Zaid H. Temrikar
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN38163
| | - Pradeep B. Lukka
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN38163
| | - Bernd Meibohm
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN38163
| | - Yury S. Polikanov
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL60607
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL60607
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL60607
| | - Sven N. Hobbie
- Institute of Medical Microbiology, University of Zurich, ZurichCH-8006, Switzerland
| | - Erik C. Böttger
- Institute of Medical Microbiology, University of Zurich, ZurichCH-8006, Switzerland
- National Reference Center for Mycobacteria, ZurichCH-8006, Switzerland
| | - Peter Sander
- Institute of Medical Microbiology, University of Zurich, ZurichCH-8006, Switzerland
- National Reference Center for Mycobacteria, ZurichCH-8006, Switzerland
| | - Richard E. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN38105
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9
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Kumar TA, Birua S, SharathChandra M, Mukherjee P, Singh S, Kaul G, Akhir A, Chopra S, Hirschi J, Singh A, Chakrapani H. An Arm-to-Disarm Strategy to Overcome Phenotypic AMR in Mycobacterium tuberculosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.23.533925. [PMID: 38260651 PMCID: PMC10802243 DOI: 10.1101/2023.03.23.533925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Most front-line tuberculosis drugs are ineffective against hypoxic non-replicating drug-tolerant Mycobacterium tuberculosis (Mtb) contributing to phenotypic antimicrobial resistance (AMR). This is largely due to the poor permeability in the thick and waxy cell wall of persister cells, leading to diminished drug accumulation and reduced drug-target engagement. Here, using an "arm-to-disarm" prodrug approach, we demonstrate that non-replicating Mtb persisters can be sensitized to Moxifloxacin (MXF), a front-line TB drug. We design and develop a series of nitroheteroaryl MXF prodrugs that are substrates for bacterial nitroreductases (NTR), a class of enzymes that are over-expressed in hypoxic Mtb. Enzymatic activation involves electron-transfer to the nitroheteroaryl compound followed by protonation via water that contributes to the rapid cleavage rate of the protective group by NTR to produce the active drug. Phenotypic and genotypic data are fully consistent with MXF-driven lethality of the prodrug in Mtb with the protective group being a relatively innocuous bystander. The prodrug increased intracellular concentrations of MXF than MXF alone and is more lethal than MXF in non-replicating persisters. Hence, arming drugs to improve permeability, accumulation and drug-target engagement is a new therapeutic paradigm to disarm phenotypic AMR.
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Affiliation(s)
- T. Anand Kumar
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, India
| | - Shalini Birua
- Division of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | | | - Piyali Mukherjee
- Division of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Samsher Singh
- Division of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Grace Kaul
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Janakipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Abdul Akhir
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Janakipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India
| | - Sidharth Chopra
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Janakipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | | | - Amit Singh
- Division of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Harinath Chakrapani
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, India
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10
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Dash R, Holsinger KA, Chordia MD, Sharifian Gh M, Pires MM. Bioluminescence-Based Determination of Cytosolic Accumulation of Antibiotics in Escherichia coli. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.06.570448. [PMID: 38106213 PMCID: PMC10723488 DOI: 10.1101/2023.12.06.570448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Antibiotic resistance is an alarming public health concern that affects millions of individuals across the globe each year. A major challenge in the development of effective antibiotics lies in their limited ability to permeate into cells, noting that numerous susceptible antibiotic targets reside within the bacterial cytosol. Consequently, improving cellular permeability is often a key consideration during antibiotic development, underscoring the need for reliable methods to assess the permeability of molecules across cellular membranes. Currently, methods used to measure permeability often fail to discriminate between arrival within the cytoplasm and the overall association of molecules with the cell. Additionally, these techniques typically possess throughput limitations. In this work, we describe a luciferase-based assay designed for assessing the permeability of molecules into the cytosolic compartment of Gram-negative bacteria. Our findings demonstrate a robust system that can elucidate the kinetics of intracellular antibiotics accumulation in live bacterial cells in real time.
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11
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Geddes EJ, Gugger MK, Garcia A, Chavez MG, Lee MR, Perlmutter SJ, Bieniossek C, Guasch L, Hergenrother PJ. Porin-independent accumulation in Pseudomonas enables antibiotic discovery. Nature 2023; 624:145-153. [PMID: 37993720 PMCID: PMC11254092 DOI: 10.1038/s41586-023-06760-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/18/2023] [Indexed: 11/24/2023]
Abstract
Gram-negative antibiotic development has been hindered by a poor understanding of the types of compounds that can accumulate within these bacteria1,2. The presence of efflux pumps and substrate-specific outer-membrane porins in Pseudomonas aeruginosa renders this pathogen particularly challenging3. As a result, there are few antibiotic options for P. aeruginosa infections4 and its many porins have made the prospect of discovering general accumulation guidelines seem unlikely5. Here we assess the whole-cell accumulation of 345 diverse compounds in P. aeruginosa and Escherichia coli. Although certain positively charged compounds permeate both bacterial species, P. aeruginosa is more restrictive compared to E. coli. Computational analysis identified distinct physicochemical properties of small molecules that specifically correlate with P. aeruginosa accumulation, such as formal charge, positive polar surface area and hydrogen bond donor surface area. Mode of uptake studies revealed that most small molecules permeate P. aeruginosa using a porin-independent pathway, thus enabling discovery of general P. aeruginosa accumulation trends with important implications for future antibiotic development. Retrospective antibiotic examples confirmed these trends and these discoveries were then applied to expand the spectrum of activity of a gram-positive-only antibiotic, fusidic acid, into a version that demonstrates a dramatic improvement in antibacterial activity against P. aeruginosa. We anticipate that these discoveries will facilitate the design and development of high-permeating antipseudomonals.
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Affiliation(s)
- Emily J Geddes
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Morgan K Gugger
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Alfredo Garcia
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Martin Garcia Chavez
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Myung Ryul Lee
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Sarah J Perlmutter
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Christoph Bieniossek
- Roche Pharma Research and Early Development, Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Laura Guasch
- Roche Pharma Research and Early Development, Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Paul J Hergenrother
- Department of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA.
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12
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Ma Z, Yan XM, Geng J, Gao L, Du W, Li HB, Yuan LX, Zhou ZY, Zhang JS, Zhang Y, Chen L. Genome-wide identification and analysis of TMT-based proteomes in longissimus dorsi tissue from Kazakh cattle and Xinjiang brown cattle. Anim Biotechnol 2023; 34:1261-1272. [PMID: 34965845 DOI: 10.1080/10495398.2021.2019756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
With the gradual completion of the human genome project, proteomes have gained extremely important value in the fields of human disease and biological process research. In our previous research, we performed transcriptomic analyses of longissimus dorsi tissue from Kazakh cattle and Xinjiang brown cattle and conducted in-depth studies on the muscles of both species through epigenetics. However, it is unclear whether differentially expressed proteins in Kazakh cattle and Xinjiang brown cattle regulate muscle production and development. In this study, a proteomic analysis was performed on Xinjiang brown cattle and Kazakh cattle by using TMT markers, HPLC classification, LC/MS and bioinformatics analysis. A total of 13,078 peptides were identified, including 11,258 unique peptides. We identified a total of 1874 proteins, among which 1565 were quantifiable. Compared to Kazakh cattle, Xinjiang brown cattle exhibited 75 upregulated proteins and 44 downregulated proteins. These differentially expressed proteins were enriched for the functions of adrenergic signaling in cardiomyocytes, fatty acid degradation and glutathione metabolism. In our research, we found differentially expressed proteins in longissimus dorsi tissue between Kazakh cattle and Xinjiang brown cattle. We predict that these proteins regulate muscle production and development through select enriched signaling pathways. This study provides novel insights into the roles of proteomes in cattle genetics and breeding.
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Affiliation(s)
- Zhen Ma
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Xiang-Min Yan
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Juan Geng
- Xinjiang Animal Husbandry General Station, Urumqi, China
| | - Liang Gao
- Yili Vocational and Technical College, Yili, China
| | - Wei Du
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Hong-Bo Li
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Li-Xing Yuan
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Zhen-Yong Zhou
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Jin-Shan Zhang
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Yang Zhang
- Institute of Animal Husbandry, Xinjiang Academy of Animal Husbandry, Urumqi, China
| | - Lei Chen
- School of Animal Science and Technology, Shihezi University, Shihezi, China
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13
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Ding T, Liu L, Liu Y, Jiang S, Guo W, Liu R, He L. Chiral separation of racemic closantel and ultratrace detection of its enantiomers in bacteria by enhanced liquid chromatography-tandem mass spectrometry combined with postcolumn infusion of ammonia. J Chromatogr A 2023; 1698:464001. [PMID: 37087856 DOI: 10.1016/j.chroma.2023.464001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/30/2023] [Accepted: 04/16/2023] [Indexed: 04/25/2023]
Abstract
Reliable analysis of ultratrace antibiotics in bacterial cells may become a new means to elucidate the antibacterial mechanism, drug resistance and environmental fate. In this work, an ultrahigh-sensitive, accurate and enhanced liquid chromatography-tandem mass spectrometric method was first developed for chiral separation and detection of racemic closantel, as an antibacterial adjuvant. Optimizing acetonitrile-water-formic acid system that is compatible with mass spectrometry as a mobile phase, the baseline separation of two enantiomers was achieved by using EnantioPak® Y1-R chiral column, and the resolution of the two analytes was more than 1.95. Further adopt the strategy of postcolumn infusion of ammonia, the mobile phase pH was reversed from acidic condition suitable for the optimal chromatographic separation of R- and S-closantel to alkaline, so that closantel could realize efficient electrospray ionization under the preferred negative ion mode. The bacterial cells were subjected to be frozen-cracked, and the analytes were extracted with acetonitrile after clipping the pointed bottom of the Eppendorf tube into a new tube. The method was linear over concentration ranges of 0.5-50 pg/mL (r2≥0.99) for R- and S-closantel. The detection limits of target analytes were all 0.15 pg/mL in bacterial cells. The average recoveries of two enantiomers ranged from 81.2% to 107.8% with relative standard deviations below 15%. The method proposed might be important support for the deep research of the stereoselectivity of biological activity, toxicity and metabolism of closantel enantiomers.
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Affiliation(s)
- Tongyan Ding
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China; National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University (SCAU), Guangzhou, 510642, China
| | - Longyun Liu
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China
| | - Yilei Liu
- National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University (SCAU), Guangzhou, 510642, China
| | - Shuanghui Jiang
- National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University (SCAU), Guangzhou, 510642, China
| | - Wenying Guo
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China
| | - Rong Liu
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China
| | - Limin He
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China; National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University (SCAU), Guangzhou, 510642, China.
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14
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Liu DY, Phillips L, Wilson DM, Fulton KM, Twine SM, Wong A, Linington RG. Collateral sensitivity profiling in drug-resistant Escherichia coli identifies natural products suppressing cephalosporin resistance. Nat Commun 2023; 14:1976. [PMID: 37031190 PMCID: PMC10082850 DOI: 10.1038/s41467-023-37624-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/22/2023] [Indexed: 04/10/2023] Open
Abstract
The rapid emergence of antimicrobial resistance presents serious health challenges to the management of infectious diseases, a problem that is further exacerbated by slowing rates of antimicrobial drug discovery in recent years. The phenomenon of collateral sensitivity (CS), whereby resistance to one drug is accompanied by increased sensitivity to another, provides new opportunities to address both these challenges. Here, we present a high-throughput screening platform termed Collateral Sensitivity Profiling (CSP) to map the difference in bioactivity of large chemical libraries across 29 drug-resistant strains of E. coli. CSP screening of 80 commercial antimicrobials demonstrated multiple CS interactions. Further screening of a 6195-member natural product library revealed extensive CS relationships in nature. In particular, we report the isolation of known and new analogues of borrelidin A with potent CS activities against cephalosporin-resistant strains. Co-dosing ceftazidime with borrelidin A slows broader cephalosporin resistance with no recognizable resistance to borrelidin A itself.
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Affiliation(s)
- Dennis Y Liu
- Department of Chemistry, Simon Fraser University, 8888 University Dr., V5A 1S6, Burnaby, BC, Canada
| | - Laura Phillips
- Department of Biology, Carleton University, 1125 Colonel By Dr., K1S 5B6, Ottawa, ON, Canada
| | - Darryl M Wilson
- Department of Chemistry, Simon Fraser University, 8888 University Dr., V5A 1S6, Burnaby, BC, Canada
| | - Kelly M Fulton
- Human Health Therapeutics Research Center, National Research Council Canada, 100 Sussex Dr., K1N 5A2, Ottawa, ON, Canada
| | - Susan M Twine
- Department of Biology, Carleton University, 1125 Colonel By Dr., K1S 5B6, Ottawa, ON, Canada
- Human Health Therapeutics Research Center, National Research Council Canada, 100 Sussex Dr., K1N 5A2, Ottawa, ON, Canada
| | - Alex Wong
- Department of Biology, Carleton University, 1125 Colonel By Dr., K1S 5B6, Ottawa, ON, Canada
- Institute for Advancing Health Through Agriculture, Texas A&M AgriLife, 1500 Research Parkway, 77845, College Station, TX, USA
| | - Roger G Linington
- Department of Chemistry, Simon Fraser University, 8888 University Dr., V5A 1S6, Burnaby, BC, Canada.
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15
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Ahn YM, Lavin RC, Tan S, Freundlich JS. Liquid chromatography-mass spectrometry-based protocol to measure drug accumulation in Mycobacterium tuberculosis and its host cell. STAR Protoc 2023; 4:101971. [PMID: 36598855 PMCID: PMC9826881 DOI: 10.1016/j.xpro.2022.101971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/31/2022] [Accepted: 12/09/2022] [Indexed: 01/05/2023] Open
Abstract
The extent to which a drug accumulates in Mycobacterium tuberculosis (Mtb) and its host cell can affect treatment efficacy. We describe protocols measuring drug accumulation in Mtb, macrophages, and Mtb-infected macrophages. The method leverages drug extraction from the cellular lysate and drug-level quantification by liquid chromatography-mass spectrometry. The general methodology has broad applicability and can quantify drug accumulation in other cell types, while being extended to quantification of drug metabolites formed within the cell under study. For complete details on the use and execution of this protocol, please refer to Lavin et al. (2021).1.
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Affiliation(s)
- Yong-Mo Ahn
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University - New Jersey Medical School, Newark, NJ 07101, USA
| | - Richard C Lavin
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA; Graduate Program in Molecular Microbiology, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA; Graduate Program in Molecular Microbiology, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA.
| | - Joel S Freundlich
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University - New Jersey Medical School, Newark, NJ 07101, USA; Division of Infectious Disease, Department of Medicine and the Ruy V. Lourenco Center for the Study of Emerging and Re-emerging Pathogens, Rutgers University - New Jersey Medical School, Newark, NJ 07103, USA.
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16
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Kim C, Tomoshige S, Lee M, Zgurskaya HI, Mobashery S. Penetration through Outer Membrane and Efflux Potential in Pseudomonas aeruginosa of Bulgecin A as an Adjuvant to β-Lactam Antibiotics. Antibiotics (Basel) 2023; 12:antibiotics12020358. [PMID: 36830269 PMCID: PMC9952357 DOI: 10.3390/antibiotics12020358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
The treatment of infections by Gram-negative bacteria remains a difficult clinical challenge. In the light of the dearth of discovery of novel antibiotics, one strategy that is being explored is the use of adjuvants to enhance antibacterial activities of existing antibiotics. One such adjuvant is bulgecin A, which allows for the lowering of minimal-inhibitory concentrations for β-lactam antibiotics. We have shown that bulgecin A inhibits three of the pseudomonal lytic transglycosylases in its mode of action, yet high concentrations are needed for potentiation activity. Herein, we document that bulgecin A is not a substrate for pseudomonal efflux pumps, whose functions could have been a culprit in the need for high concentrations. We present evidence that the penetration barrier into the periplasm is at the root of the need for high concentrations of bulgecin A in its potentiation of β-lactam antibiotics.
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Affiliation(s)
- Choon Kim
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Shusuke Tomoshige
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
- Correspondence: ; Tel.: +1-574-631-2933
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17
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Improved LC/MS/MS Quantification Using Dual Deuterated Isomers as the Surrogates: A Case Analysis of Enrofloxacin Residue in Aquatic Products. Foods 2023; 12:foods12010224. [PMID: 36613439 PMCID: PMC9818688 DOI: 10.3390/foods12010224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/23/2022] [Accepted: 12/26/2022] [Indexed: 01/05/2023] Open
Abstract
Extensive and high residue variations in enrofloxacin (ENR) exist in different aquatic products. A novel quantitative method for measuring ENR using high-performance liquid chromatography-tandem mass spectrometry was developed employing enrofloxacin-d5 (ENR-d5) and enrofloxacin-d3 (ENR-d3) as isotope surrogates. This reduced the deviation of detected values, which results from the overpass of the linear range and/or the large difference in the residue between the isotope standard and ENR, from the actual content. Furthermore, high residue levels of ENR can be directly diluted and re-calibrated by the corresponding curve with the addition of high levels of another internal surrogate without repeated sample preparation, avoiding the overflow of the instrument response. The validation results demonstrated that the method can simultaneously determine ENR residues from MQL (2 µg/kg) to 5000 × MQL (method quantification limit) with recoveries between 97.1 and 106%, and intra-precision of no more than 2.14%. This method realized a wide linear calibration range with dual deuterated isomers, which has not been previously reported in the literature. The developed method was successfully applied to the analysis of ENR in different aquatic products, with ENR residue levels varying from 108 to 4340 μg/kg and an interval of precision in the range of 0.175~6.72%. These results demonstrate that batch samples with a high variation in ENR residues (over the linear range with a single isotope standard) can be detected by the dual isotope surrogates method in a single sample preparation process.
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18
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Hurst-Hess KR, Phelps GA, Wilt LA, Lee RE, Ghosh P. Mab2780c, a TetV-like efflux pump, confers high-level spectinomycin resistance in mycobacterium abscessus. Tuberculosis (Edinb) 2023; 138:102295. [PMID: 36584486 PMCID: PMC10228334 DOI: 10.1016/j.tube.2022.102295] [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] [Received: 10/14/2022] [Revised: 12/08/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Mycobacterium abscessus is highly resistant to spectinomycin (SPC) thereby making it unavailable for therapeutic use. Sublethal exposure to SPC strongly induces whiB7 and its regulon, and a ΔMab_whiB7 strain is SPC sensitive suggesting that the determinants of SPC resistance are included within its regulon. In the present study we have determined the transcriptomic changes that occur in M. abscessus upon SPC exposure and have evaluated the involvement of 11 genes, that are both strongly SPC induced and whiB7 dependent, in SPC resistance. Of these we show that MAB_2780c can complement SPC sensitivity of ΔMab_whiB7 and that a ΔMab_2780c strain is ∼150 fold more SPC sensitive than wildtype bacteria, but not to tetracycline (TET) or other aminoglycosides. This is in contrast to its homologues, TetV from M. smegmatis and Tap from M. tuberculosis, that confer low-level resistance to TET, SPC and other aminoglycosides. We also show that the addition of the efflux pump inhibitor (EPI), verapamil results in >100-fold decrease in MIC of SPC in bacteria expressing Mab2780c to the levels observed for ΔMab_2780c; moreover a deletion of MAB_2780c results in a decreased efflux of the drug into the cell supernatant. Together our data suggest that Mab2780c is an SPC antiporter. Finally, molecular docking of SPC and TET on models of TetVMs and Mab2780c confirmed our antibacterial susceptibility findings that the Mab2780c pump preferentially effluxes SPC over TET. To our knowledge, this is the first report of an efflux pump that confers high-level drug resistance in M. abscessus. The identification of Mab2780c in SPC resistance opens up prospects for repurposing this relatively well-tolerated antibiotic as a combination therapy with verapamil or its analogs against M. abscessus infections.
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Affiliation(s)
- Kelley R Hurst-Hess
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
| | - Greg A Phelps
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Laura A Wilt
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Richard E Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Pallavi Ghosh
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA; School of Public Health, University at Albany, Albany, NY, 12208, USA.
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19
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Pugh BA, Rao AB, Angeles-Solano M, Grosser MR, Brock JW, Murphy KE, Wolfe AL. Design and evaluation of poly-nitrogenous adjuvants capable of potentiating antibiotics in Gram-negative bacteria. RSC Med Chem 2022; 13:1058-1063. [PMID: 36324495 PMCID: PMC9491355 DOI: 10.1039/d2md00041e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 07/05/2022] [Indexed: 01/03/2023] Open
Abstract
Antibiotic resistance has been a growing public health crisis since the 1980s. Therefore, it is essential not only to continue to develop novel antibiotics but also to develop new methods for overcoming resistance mechanisms in pathogenic bacteria so antibiotics can be reactivated towards these resistant strains. One common cause of antibiotic resistance in Gram-negative bacteria is reduced permeability of the tightly packed, negatively charged lipopolysaccharide outer membrane (OM), which dramatically reduces or even prevents antibiotic accumulation within the cell. Adjuvants that promote passive diffusion through the OM, including phenylalanine-arginine-β-naphthylamide, tobramycin, and pentamidine, have proven useful in potentiating antibiotics against Gram-negative bacteria. Structural evaluation of these adjuvants, which all include multiple nitrogenous groups, indicates that the entry rules developed for improving antibiotic accumulation in Escherichia coli (EC), could also be used to guide adjuvant development. To this end, a series of structurally simple poly-nitrogenous diphenylsuccinamide compounds have been prepared and evaluated for their ability to potentiate a panel of classic antibiotics in wild-type EC and Pseudomonas aeruginosa (PA). Modest adjuvant activity was observed for all compounds surveyed when co-administered with known antibiotics to inhibit either wild-type EC or PA, and all were able to accumulate in both EC and PA.
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Affiliation(s)
- Bryce A. Pugh
- Department of Chemistry and Biochemistry, University of North Carolina AshevilleOne University HeightsAshevilleNorth Carolina28804USA
| | - Aliyah B. Rao
- Department of Chemistry and Biochemistry, University of North Carolina AshevilleOne University HeightsAshevilleNorth Carolina28804USA
| | - Michelle Angeles-Solano
- Department of Biology, University of North Carolina AshevilleOne University HeightsAshevilleNorth Carolina28804USA
| | - Melinda R. Grosser
- Department of Biology, University of North Carolina AshevilleOne University HeightsAshevilleNorth Carolina28804USA
| | - John W. Brock
- Department of Chemistry and Biochemistry, University of North Carolina AshevilleOne University HeightsAshevilleNorth Carolina28804USA
| | - Kyle E. Murphy
- Department of Chemistry and Biochemistry, University of North Carolina AshevilleOne University HeightsAshevilleNorth Carolina28804USA
| | - Amanda L. Wolfe
- Department of Chemistry and Biochemistry, University of North Carolina AshevilleOne University HeightsAshevilleNorth Carolina28804USA
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20
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Parker E, Cain BN, Hajian B, Ulrich RJ, Geddes EJ, Barkho S, Lee HY, Williams JD, Raynor M, Caridha D, Zaino A, Shekhar M, Muñoz KA, Rzasa KM, Temple ER, Hunt D, Jin X, Vuong C, Pannone K, Kelly AM, Mulligan MP, Lee KK, Lau GW, Hung DT, Hergenrother PJ. An Iterative Approach Guides Discovery of the FabI Inhibitor Fabimycin, a Late-Stage Antibiotic Candidate with In Vivo Efficacy against Drug-Resistant Gram-Negative Infections. ACS CENTRAL SCIENCE 2022; 8:1145-1158. [PMID: 36032774 PMCID: PMC9413440 DOI: 10.1021/acscentsci.2c00598] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Indexed: 05/13/2023]
Abstract
Genomic studies and experiments with permeability-deficient strains have revealed a variety of biological targets that can be engaged to kill Gram-negative bacteria. However, the formidable outer membrane and promiscuous efflux pumps of these pathogens prevent many candidate antibiotics from reaching these targets. One such promising target is the enzyme FabI, which catalyzes the rate-determining step in bacterial fatty acid biosynthesis. Notably, FabI inhibitors have advanced to clinical trials for Staphylococcus aureus infections but not for infections caused by Gram-negative bacteria. Here, we synthesize a suite of FabI inhibitors whose structures fit permeation rules for Gram-negative bacteria and leverage activity against a challenging panel of Gram-negative clinical isolates as a filter for advancement. The compound to emerge, called fabimycin, has impressive activity against >200 clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii, and does not kill commensal bacteria. X-ray structures of fabimycin in complex with FabI provide molecular insights into the inhibition. Fabimycin demonstrates activity in multiple mouse models of infection caused by Gram-negative bacteria, including a challenging urinary tract infection model. Fabimycin has translational promise, and its discovery provides additional evidence that antibiotics can be systematically modified to accumulate in Gram-negative bacteria and kill these problematic pathogens.
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Affiliation(s)
- Erica
N. Parker
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Brett N. Cain
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Behnoush Hajian
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Rebecca J. Ulrich
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Emily J. Geddes
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Sulyman Barkho
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Hyang Yeon Lee
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - John D. Williams
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Malik Raynor
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Diana Caridha
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Angela Zaino
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Mrinal Shekhar
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Kristen A. Muñoz
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Kara M. Rzasa
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Emily R. Temple
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Diana Hunt
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department
of Molecular Biology and Center for Computational and Integrative
Biology, Massachusetts General Hospital, Boston, Massachusetts 02115, United States
| | - Xiannu Jin
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Chau Vuong
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Kristina Pannone
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Aya M. Kelly
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Michael P. Mulligan
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Katie K. Lee
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Gee W. Lau
- Department
of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Deborah T. Hung
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department
of Molecular Biology and Center for Computational and Integrative
Biology, Massachusetts General Hospital, Boston, Massachusetts 02115, United States
| | - Paul J. Hergenrother
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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21
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Chemical Exploration of a Highly Selective Scaffold with Activity against Intracellular Mycobacterium tuberculosis. Microbiol Spectr 2022; 10:e0116122. [PMID: 35612308 PMCID: PMC9241686 DOI: 10.1128/spectrum.01161-22] [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] [Indexed: 11/28/2022] Open
Abstract
We previously identified a phenylthiourea series with activity against intracellular Mycobacterium tuberculosis using a high-throughput, high-content assay. We conducted a catalog structure-activity relationship study with a collection of 35 analogs. We identified several thiourea derivatives with excellent potency against intracellular bacteria and good selectivity over eukaryotic cells. Compounds had much lower activity against extracellular bacteria, which was not increased by using cholesterol as the sole carbon source. Compounds were equally active against strains with mutations in QcrB or MmpL3, thereby excluding common, promiscuous targets as the mode of action. The phenylthiourea series represents a good starting point for further exploration to develop novel antitubercular agents. IMPORTANCEMycobacterium tuberculosis is responsible for the highest number of deaths from a bacterial pathogen, with >1.5 million in 2020. M. tuberculosis is a sophisticated pathogen that can replicate inside immune cells. There is an urgent need for new drugs to combat M. tuberculosis and to shorten therapy from 6 to 24 months. We have identified a series of molecules that inhibit the growth of M. tuberculosis inside macrophages; we tested a number of derivatives to link structural features to biological activity. The compounds are likely to have novel mechanism of action and so could be developed as new agents for drug-resistant tuberculosis.
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22
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On the Hunt for Next-Generation Antimicrobial Agents: An Online Symposium Organized Jointly by the French Society for Medicinal Chemistry (Société de Chimie Thérapeutique) and the French Microbiology Society (Société Française de Microbiologie) on 9–10 December 2021. Pharmaceuticals (Basel) 2022; 15:ph15040388. [PMID: 35455385 PMCID: PMC9029193 DOI: 10.3390/ph15040388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 03/17/2022] [Indexed: 01/27/2023] Open
Abstract
The restrictions posed by the COVID-19 pandemic obliged the French Society for Medicinal Chemistry (Société de chimie thérapeutique) and the French Microbiology Society (Société Française de Microbiologie) to organize their joint autumn symposium (entitled “On the hunt for next-generation antimicrobial agents”) online on 9–10 December 2021. The meeting attracted more than 200 researchers from France and abroad with interests in drug discovery, antimicrobial resistance, medicinal chemistry, and related disciplines. This review summarizes the 13 invited keynote lectures. The symposium generated high-level scientific dialogue on the most recent advances in combating antimicrobial resistance. The University of Lille, the Institut Pasteur de Lille, the journal Pharmaceuticals, Oxeltis, and INCATE, sponsored the event.
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23
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Dharuman S, Wallace MJ, Reeve SM, Bulitta JB, Lee RE. Synthesis and Structure–Activity Relationship of Thioacetamide-Triazoles against Escherichia coli. Molecules 2022; 27:molecules27051518. [PMID: 35268619 PMCID: PMC8911640 DOI: 10.3390/molecules27051518] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 02/04/2023] Open
Abstract
Infections due to Gram-negative bacteria are increasingly dangerous due to the spread of multi-drug resistant strains, emphasizing the urgent need for new antibiotics with alternative modes of action. We have previously identified a novel class of antibacterial agents, thioacetamide-triazoles, using an antifolate targeted screen and determined their mode of action which is dependent on activation by cysteine synthase A. Herein, we report a detailed examination of the anti-E. coli structure–activity relationship of the thioacetamide-triazoles. Analogs of the initial hit compounds were synthesized to study the contribution of the aryl, thioacetamide, and triazole sections. A clear structure–activity relationship was observed generating compounds with excellent inhibition values. Substitutions to the aryl ring were generally best tolerated, including the introduction of thiazole and pyridine heteroaryl systems. Substitutions to the central thioacetamide linker section were more nuanced; the introduction of a methyl branch to the thioacetamide linker substantially decreased antibacterial activity, but the isomeric propionamide and N-benzamide systems retained activity. Changes to the triazole portion of the molecule dramatically decreased the antibacterial activity, further indicating that 1,2,3-triazole is critical for potency. From these studies, we have identified new lead compounds with desirable in-vitro ADME properties and in-vivo pharmacokinetic properties.
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Affiliation(s)
- Suresh Dharuman
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (S.D.); (M.J.W.); (S.M.R.)
| | - Miranda J. Wallace
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (S.D.); (M.J.W.); (S.M.R.)
- Department of Pathology & Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stephanie M. Reeve
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (S.D.); (M.J.W.); (S.M.R.)
| | - Jürgen B. Bulitta
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, FL 31836, USA;
| | - Richard E. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (S.D.); (M.J.W.); (S.M.R.)
- Correspondence:
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24
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Role of internal loop dynamics in antibiotic permeability of outer membrane porins. Proc Natl Acad Sci U S A 2022; 119:2117009119. [PMID: 35193963 PMCID: PMC8872756 DOI: 10.1073/pnas.2117009119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2022] [Indexed: 12/26/2022] Open
Abstract
Antibiotic resistance in Gram-negative pathogens has been identified as an urgent threat to human health by the World Health Organization. The major challenge with treating infections by these pathogens is developing antibiotics that can traverse the dense bacterial outer membrane (OM) formed by a mesh of lipopolysaccharides. Effective antibiotics permeate through OM porins, which have evolved for nutrient diffusion; however, the conformational states of these porins regulating permeation are still unclear. Here, we used molecular dynamics simulations, free energy calculations, Markov-state modeling, and whole-cell accumulation assays to provide mechanistic insight on how a porin shifts between open and closed states. We provide a mechanism of how Gram-negative bacteria confer resistance to antibiotics. Gram-negative bacteria pose a serious public health concern due to resistance to many antibiotics, caused by the low permeability of their outer membrane (OM). Effective antibiotics use porins in the OM to reach the interior of the cell; thus, understanding permeation properties of OM porins is instrumental to rationally develop broad-spectrum antibiotics. A functionally important feature of OM porins is undergoing open–closed transitions that modulate their transport properties. To characterize the molecular basis of these transitions, we performed an extensive set of molecular dynamics (MD) simulations of Escherichia coli OM porin OmpF. Markov-state analysis revealed that large-scale motion of an internal loop, L3, underlies the transition between energetically stable open and closed states. The conformation of L3 is controlled by H bonds between highly conserved acidic residues on the loop and basic residues on the OmpF β-barrel. Mutation of key residues important for the loop’s conformation shifts the equilibrium between open and closed states and regulates translocation of permeants (ions and antibiotics), as observed in the simulations and validated by our whole-cell accumulation assay. Notably, one mutant system G119D, which we find to favor the closed state, has been reported in clinically resistant bacterial strains. Overall, our accumulated ∼200 µs of simulation data (the wild type and mutants) along with experimental assays suggest the involvement of internal loop dynamics in permeability of OM porins and antibiotic resistance in Gram-negative bacteria.
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25
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Haloi N, Vasan AK, Geddes EJ, Prasanna A, Wen PC, Metcalf WW, Hergenrother PJ, Tajkhorshid E. Rationalizing the generation of broad spectrum antibiotics with the addition of a positive charge. Chem Sci 2021; 12:15028-15044. [PMID: 34909143 PMCID: PMC8612397 DOI: 10.1039/d1sc04445a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/13/2021] [Indexed: 11/28/2022] Open
Abstract
Antibiotic resistance of Gram-negative bacteria is largely attributed to the low permeability of their outer membrane (OM). Recently, we disclosed the eNTRy rules, a key lesson of which is that the introduction of a primary amine enhances OM permeation in certain contexts. To understand the molecular basis for this finding, we perform an extensive set of molecular dynamics (MD) simulations and free energy calculations comparing the permeation of aminated and amine-free antibiotic derivatives through the most abundant OM porin of E. coli, OmpF. To improve sampling of conformationally flexible drugs in MD simulations, we developed a novel, Monte Carlo and graph theory based algorithm to probe more efficiently the rotational and translational degrees of freedom visited during the permeation of the antibiotic molecule through OmpF. The resulting pathways were then used for free-energy calculations, revealing a lower barrier against the permeation of the aminated compound, substantiating its greater OM permeability. Further analysis revealed that the amine facilitates permeation by enabling the antibiotic to align its dipole to the luminal electric field of the porin and form favorable electrostatic interactions with specific, highly-conserved charged residues. The importance of these interactions in permeation was further validated with experimental mutagenesis and whole cell accumulation assays. Overall, this study provides insights on the importance of the primary amine for antibiotic permeation into Gram-negative pathogens that could help the design of future antibiotics. We also offer a new computational approach for calculating free-energy of processes where relevant molecular conformations cannot be efficiently captured.
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Affiliation(s)
- Nandan Haloi
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Archit Kumar Vasan
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Emily J Geddes
- Department of Chemistry, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Arjun Prasanna
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
- Department of Microbiology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Po-Chao Wen
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - William W Metcalf
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
- Department of Microbiology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Paul J Hergenrother
- Department of Chemistry, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
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