1
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Yildirim O, Barman D, Chung M, Stone S, Geißen R, Boby ML, Sherborne BS, Tan DS. Design and synthesis of a library of C8-substituted sulfamidoadenosines to probe bacterial permeability. Bioorg Med Chem Lett 2024; 110:129844. [PMID: 38851357 DOI: 10.1016/j.bmcl.2024.129844] [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: 04/24/2024] [Revised: 05/30/2024] [Accepted: 06/05/2024] [Indexed: 06/10/2024]
Abstract
Gram-negative bacteria pose a major challenge in antibiotic drug discovery because their cell envelope presents a permeability barrier that affords high intrinsic resistance to small-molecule drugs. The identification of correlations between chemical structure and Gram-negative permeability would thus enable development of predictive tools to facilitate antibiotic discovery. Toward this end, have advanced a library design paradigm in which various chemical scaffolds are functionalized at different regioisomeric positions using a uniform reagent set. This design enables decoupling of scaffold, regiochemistry, and substituent effects upon Gram-negative permeability of these molecules. Building upon our recent synthesis of a library of C2-substituted sulfamidoadenosines, we have now developed an efficient synthetic route to an analogous library of regioisomeric C8-substituted congeners. The C8 library samples a region of antibiotic-relevant chemical space that is similar to that addressed by the C2 library, but distinct from that sampled by a library of analogously substituted oxazolidinones. Selected molecules were tested for accumulation in Escherichia coli in a pilot analysis, setting the stage for full comparative evaluation of these libraries in the future.
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Affiliation(s)
- Okan Yildirim
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Dipti Barman
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Mia Chung
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Samantha Stone
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Raphael Geißen
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Doctoral Program, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Melissa L Boby
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Pharmacology Graduate Program, Weill Cornell Graduate School, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | | | - Derek S Tan
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Pharmacology Graduate Program, Weill Cornell Graduate School, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
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2
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Parkhill SL, Johnson EO. Integrating bacterial molecular genetics with chemical biology for renewed antibacterial drug discovery. Biochem J 2024; 481:839-864. [PMID: 38958473 DOI: 10.1042/bcj20220062] [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: 05/07/2024] [Revised: 06/20/2024] [Accepted: 06/24/2024] [Indexed: 07/04/2024]
Abstract
The application of dyes to understanding the aetiology of infection inspired antimicrobial chemotherapy and the first wave of antibacterial drugs. The second wave of antibacterial drug discovery was driven by rapid discovery of natural products, now making up 69% of current antibacterial drugs. But now with the most prevalent natural products already discovered, ∼107 new soil-dwelling bacterial species must be screened to discover one new class of natural product. Therefore, instead of a third wave of antibacterial drug discovery, there is now a discovery bottleneck. Unlike natural products which are curated by billions of years of microbial antagonism, the vast synthetic chemical space still requires artificial curation through the therapeutics science of antibacterial drugs - a systematic understanding of how small molecules interact with bacterial physiology, effect desired phenotypes, and benefit the host. Bacterial molecular genetics can elucidate pathogen biology relevant to therapeutics development, but it can also be applied directly to understanding mechanisms and liabilities of new chemical agents with new mechanisms of action. Therefore, the next phase of antibacterial drug discovery could be enabled by integrating chemical expertise with systematic dissection of bacterial infection biology. Facing the ambitious endeavour to find new molecules from nature or new-to-nature which cure bacterial infections, the capabilities furnished by modern chemical biology and molecular genetics can be applied to prospecting for chemical modulators of new targets which circumvent prevalent resistance mechanisms.
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Affiliation(s)
- Susannah L Parkhill
- Systems Chemical Biology of Infection and Resistance Laboratory, The Francis Crick Institute, London, U.K
- Faculty of Life Sciences, University College London, London, U.K
| | - Eachan O Johnson
- Systems Chemical Biology of Infection and Resistance Laboratory, The Francis Crick Institute, London, U.K
- Faculty of Life Sciences, University College London, London, U.K
- Department of Chemistry, Imperial College, London, U.K
- Department of Chemistry, King's College London, London, U.K
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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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Asnicar F, Thomas AM, Passerini A, Waldron L, Segata N. Machine learning for microbiologists. Nat Rev Microbiol 2024; 22:191-205. [PMID: 37968359 DOI: 10.1038/s41579-023-00984-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2023] [Indexed: 11/17/2023]
Abstract
Machine learning is increasingly important in microbiology where it is used for tasks such as predicting antibiotic resistance and associating human microbiome features with complex host diseases. The applications in microbiology are quickly expanding and the machine learning tools frequently used in basic and clinical research range from classification and regression to clustering and dimensionality reduction. In this Review, we examine the main machine learning concepts, tasks and applications that are relevant for experimental and clinical microbiologists. We provide the minimal toolbox for a microbiologist to be able to understand, interpret and use machine learning in their experimental and translational activities.
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Affiliation(s)
- Francesco Asnicar
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Andrew Maltez Thomas
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Andrea Passerini
- Department of Information Engineering and Computer Science, University of Trento, Trento, Italy
| | - Levi Waldron
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy.
- Department of Epidemiology and Biostatistics, City University of New York, New York, NY, USA.
| | - Nicola Segata
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy.
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy.
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5
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Ishikawa F, Konno S, Kakeya H, Tanabe G. Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells. Beilstein J Org Chem 2024; 20:445-451. [PMID: 38440174 PMCID: PMC10910458 DOI: 10.3762/bjoc.20.39] [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: 12/14/2023] [Accepted: 02/12/2024] [Indexed: 03/06/2024] Open
Abstract
The adenylation (A) domain is essential for non-ribosomal peptide synthetases (NRPSs), which synthesize various peptide-based natural products, including virulence factors, such as siderophores and genotoxins. Hence, the inhibition of A-domains could attenuate the virulence of pathogens. 5'-O-N-(Aminoacyl or arylacyl)sulfamoyladenosine (AA-AMS) is a bisubstrate small-molecule inhibitor of the A-domains of NRPSs. However, the bacterial cell permeability of AA-AMS is typically a problem owing to its high hydrophilicity. In this study, we investigated the influence of a modification of 2'-OH in the AMS scaffold with different functional groups on binding to target enzymes and bacterial cell penetration. The inhibitor 7 with a cyanomethyl group at 2'-OH showed desirable inhibitory activity against both recombinant and intracellular gramicidin S synthetase A (GrsA) in the gramicidin S-producer Aneurinibacillus migulanus ATCC 9999, providing an alternative scaffold to develop novel A-domain inhibitors.
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Affiliation(s)
- Fumihiro Ishikawa
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Sho Konno
- Department of System Chemotherapy and Molecular Sciences, Division of Medicinal Frontier Sciences, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Hideaki Kakeya
- Department of System Chemotherapy and Molecular Sciences, Division of Medicinal Frontier Sciences, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Genzoh Tanabe
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
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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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Stoorza AM, Duerfeldt AS. Guiding the Way: Traditional Medicinal Chemistry Inspiration for Rational Gram-Negative Drug Design. J Med Chem 2024; 67:65-80. [PMID: 38134355 DOI: 10.1021/acs.jmedchem.3c01831] [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] [Indexed: 12/24/2023]
Abstract
The discovery and development of small-molecule therapeutics effective against Gram-negative pathogens are highly challenging tasks. Most compounds that are active in biochemical settings fail to exhibit whole-cell activity. The major reason for this lack of activity is the effectiveness of bacterial cell envelopes as permeability barriers. These barriers originate from the nutrient-selective outer membranes, which act synergistically with polyspecific efflux pumps. Guiding principles to enable rational optimization of small molecules for efficient penetration and intracellular accumulation in Gram-negative bacteria would have a transformative impact on the discovery and design of chemical probes and therapeutics. In this Perspective, we draw on inspiration from traditional medicinal chemistry approaches for eukaryotic drug design to present a broader call for action in developing comparable approaches for Gram-negative bacteria.
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Affiliation(s)
- Alexis M Stoorza
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Adam S Duerfeldt
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55414, United States
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9
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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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10
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Zhao S, Maceren J, Chung M, Stone S, Geißen R, Boby ML, Sherborne BS, Tan DS. Design and synthesis of a library of C2-substituted sulfamidoadenosines to probe bacterial permeability. Bioorg Med Chem Lett 2024; 97:129486. [PMID: 37734424 PMCID: PMC10842738 DOI: 10.1016/j.bmcl.2023.129486] [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: 09/04/2023] [Revised: 09/18/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023]
Abstract
Antibiotic resistance is a major threat to public health, and Gram-negative bacteria pose a particular challenge due to their combination of a low permeability cell envelope and efflux pumps. Our limited understanding of the chemical rules for overcoming these barriers represents a major obstacle in antibacterial drug discovery. Several recent efforts to address this problem have involved screening compound libraries for accumulation in bacteria in order to understand the structural properties required for Gram-negative permeability. Toward this end, we used cheminformatic analysis to design a library of sulfamidoadenosines (AMSN) having diverse substituents at the adenine C2 position. An efficient synthetic route was developed with installation of a uniform cross-coupling reagent set using Sonogashira and Suzuki reactions of a C2-iodide. The potential utility of these compounds was demonstrated by pilot analysis of selected analogues for accumulation in Escherichia coli.
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Affiliation(s)
- Shibin Zhao
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
| | - Julian Maceren
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
| | - Mia Chung
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
| | - Samantha Stone
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
| | - Raphael Geißen
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA; Doctoral Program, Faculty of Biology, Albert-Ludwigs-Universität Freiburg,79104 Freiburg im Breisgau, Germany
| | - Melissa L Boby
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA; Pharmacology Graduate Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
| | | | - Derek S Tan
- Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA; Pharmacology Graduate Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA; Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA.
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11
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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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12
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Theuretzbacher U, Blasco B, Duffey M, Piddock LJV. Unrealized targets in the discovery of antibiotics for Gram-negative bacterial infections. Nat Rev Drug Discov 2023; 22:957-975. [PMID: 37833553 DOI: 10.1038/s41573-023-00791-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2023] [Indexed: 10/15/2023]
Abstract
Advances in areas that include genomics, systems biology, protein structure determination and artificial intelligence provide new opportunities for target-based antibacterial drug discovery. The selection of a 'good' new target for direct-acting antibacterial compounds is the first decision, for which multiple criteria must be explored, integrated and re-evaluated as drug discovery programmes progress. Criteria include essentiality of the target for bacterial survival, its conservation across different strains of the same species, bacterial species and growth conditions (which determines the spectrum of activity of a potential antibiotic) and the level of homology with human genes (which influences the potential for selective inhibition). Additionally, a bacterial target should have the potential to bind to drug-like molecules, and its subcellular location will govern the need for inhibitors to penetrate one or two bacterial membranes, which is a key challenge in targeting Gram-negative bacteria. The risk of the emergence of target-based drug resistance for drugs with single targets also requires consideration. This Review describes promising but as-yet-unrealized targets for antibacterial drugs against Gram-negative bacteria and examples of cognate inhibitors, and highlights lessons learned from past drug discovery programmes.
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Affiliation(s)
| | - Benjamin Blasco
- Global Antibiotic Research and Development Partnership (GARDP), Geneva, Switzerland
| | - Maëlle Duffey
- Global Antibiotic Research and Development Partnership (GARDP), Geneva, Switzerland
| | - Laura J V Piddock
- Global Antibiotic Research and Development Partnership (GARDP), Geneva, Switzerland.
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13
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Santana CP, Matter BA, Patil MA, Silva-Cunha A, Kompella UB. Corneal Permeability and Uptake of Twenty-Five Drugs: Species Comparison and Quantitative Structure-Permeability Relationships. Pharmaceutics 2023; 15:1646. [PMID: 37376094 DOI: 10.3390/pharmaceutics15061646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/28/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
The purpose of this study was to determine corneal permeability and uptake in rabbit, porcine, and bovine corneas for twenty-five drugs using an N-in-1 (cassette) approach and relate these parameters to drug physicochemical properties and tissue thickness through quantitative structure permeability relationships (QSPRs). A twenty-five-drug cassette containing β-blockers, NSAIDs, and corticosteroids in solution at a micro-dose was exposed to the epithelial side of rabbit, porcine, or bovine corneas mounted in a diffusion chamber, and the corneal drug permeability and tissue uptake were monitored using an LC-MS/MS method. Data obtained were used to construct and evaluate over 46,000 quantitative structure-permeability (QSPR) models using multiple linear regression, and the best-fit models were cross-validated by Y-randomization. Drug permeability was generally higher in rabbit cornea and comparable between bovine and porcine corneas. Permeability differences between species could be explained in part by differences in corneal thickness. Corneal uptake between species correlated with a slope close to 1, indicating generally similar drug uptake per unit weight of tissue. A high correlation was observed between bovine, porcine, and rabbit corneas for permeability and between bovine and porcine corneas for uptake (R2 ≥ 0.94). MLR models indicated that drug characteristics such as lipophilicity (LogD), heteroatom ratio (HR), nitrogen ratio (NR), hydrogen bond acceptors (HBA), rotatable bonds (RB), index of refraction (IR), and tissue thickness (TT) are of great influence on drug permeability and uptake. When data for all species along with thickness as a parameter was used in MLR, the best fit equation for permeability was Log (% transport/cm2·s) = 0.441 LogD - 8.29 IR + 8.357 NR - 0.279 HBA - 3.833 TT + 10.432 (R2 = 0.826), and the best-fit equation for uptake was Log (%/g) = 0.387 LogD + 4.442 HR + 0.105 RB - 0.303 HBA - 2.235 TT + 1.422 (R2 = 0.750). Thus, it is feasible to explain corneal drug delivery in three species using a single equation.
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Affiliation(s)
- Cleildo P Santana
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Brock A Matter
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Madhoosudan A Patil
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Armando Silva-Cunha
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Uday B Kompella
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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14
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Functional Diversity of Gram-Negative Permeability Barriers Reflected in Antibacterial Activities and Intracellular Accumulation of Antibiotics. Antimicrob Agents Chemother 2023; 67:e0137722. [PMID: 36715507 PMCID: PMC9933635 DOI: 10.1128/aac.01377-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Gram-negative bacteria are notoriously more resistant to antibiotics than Gram-positive bacteria, primarily due to the presence of the outer membrane and a plethora of active efflux pumps. However, the potency of antibiotics also varies dramatically between different Gram-negative pathogens, suggesting major mechanistic differences in how antibiotics penetrate permeability barriers. Two approaches are used broadly to analyze how permeability barriers affect intracellular accumulation of antibiotics. One compares the antibacterial activities of compounds, while the other measures the total intracellular concentrations of compounds in nongrowing cells, with both approaches using strains harboring wild-type or genetically modified efflux systems and permeability barriers. Whether the two assays provide similar mechanistic insights remains unclear. In this study, we analyzed the intracellular accumulation and antibacterial activities of antibiotics representative of major clinical classes in three Gram-negative pathogens of high clinical importance, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii. We found that both assays are informative about properties of permeability barriers, but there is no quantitative agreement between the assays. Our results show that the three pathogens differ dramatically in their permeability barriers, with the outer membrane playing the dominant role in E. coli and P. aeruginosa but efflux dominating in A. baumannii. However, even compounds of the same chemotype may use different permeation pathways depending on small chemical modifications. Accordingly, a classification analysis revealed limited conservation of molecular properties that define compound penetration into the three bacteria.
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15
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Dokla EME, Abutaleb NS, Milik SN, Kandil EAEA, Qassem OM, Elgammal Y, Nasr M, McPhillie MJ, Abouzid KAM, Seleem MN, Imming P, Adel M. SAR investigation and optimization of benzimidazole-based derivatives as antimicrobial agents against Gram-negative bacteria. Eur J Med Chem 2023; 247:115040. [PMID: 36584632 DOI: 10.1016/j.ejmech.2022.115040] [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: 09/09/2022] [Revised: 12/03/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Antibiotic-resistant bacteria represent a serious threat to modern medicine and human life. Only a minority of antibacterial agents are active against Gram-negative bacteria. Hence, the development of novel antimicrobial agents will always be a vital need. In an effort to discover new therapeutics against Gram-negative bacteria, we previously reported a structure-activity-relationship (SAR) study on 1,2-disubstituted benzimidazole derivatives. Compound III showed a potent activity against tolC-mutant Escherichia coli with an MIC value of 2 μg/mL, representing a promising lead for further optimization. Building upon this study, herein, 49 novel benzimidazole compounds were synthesized to investigate their antibacterial activity against Gram-negative bacteria. Our design focused on three main goals, to address the low permeability of our compounds and improve their cellular accumulation, to expand the SAR study to the unexplored ring C, and to optimize the lead compound (III) by modification of the methanesulfonamide moiety. Compounds (25a-d, 25f-h, 25k, 25l, 25p, 25r, 25s, and 26b) exhibited potent activity against tolC-mutant E. coli with MIC values ranging from 0.125 to 4 μg/mL, with compound 25d displaying the highest potency among the tested compounds with an MIC value of 0.125 μg/mL. As its predecessor, III, compound 25d exhibited an excellent safety profile without any significant cytotoxicity to mammalian cells. Time-kill kinetics assay indicated that 25d exhibited a bacteriostatic activity and significantly reduced E. coli JW55031 burden as compared to DMSO. Additionally, combination of 25d with colistin partially restored its antibacterial activity against Gram-negative bacterial strains (MIC values ranging from 4 to 16 μg/mL against E. coli BW25113, K. pneumoniae, A. baumannii, and P. aeruginosa). Furthermore, formulation of III and 25d as lipidic nanoparticles (nanocapsules) resulted in moderate enhancement of their antibacterial activity against Gram-negative bacterial strains (A. Baumannii, N. gonorrhoeae) and compound 25d demonstrated superior activity to the lead compound III. These findings establish compound 25d as a promising candidate for treatment of Gram-negative bacterial infections and emphasize the potential of nano-formulations in overcoming poor cellular accumulation in Gram-negative bacteria where further optimization and investigation are warranted to improve the potency and broaden the spectrum of our compounds.
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Affiliation(s)
- Eman M E Dokla
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, 11566, Egypt; Institute für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, Halle (Saale), 06120, Germany.
| | - Nader S Abutaleb
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA; Department of Microbiology and Immunology, Zagazig University, Zagazig, 44519, Egypt
| | - Sandra N Milik
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, 11566, Egypt; School of Chemistry, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Ezzat A E A Kandil
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, 11566, Egypt
| | - Omar M Qassem
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, 11566, Egypt; Purdue University Institute of Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA
| | - Yehia Elgammal
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Maha Nasr
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, 11566, Egypt
| | - Martin J McPhillie
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Khaled A M Abouzid
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, 11566, Egypt
| | - Mohamed N Seleem
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA; Center for Emerging, Zoonotic and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Peter Imming
- Institute für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, Halle (Saale), 06120, Germany
| | - Mai Adel
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, 11566, Egypt.
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16
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Ongwae GM, Lepori I, Chordia MD, Dalesandro BE, Apostolos AJ, Siegrist MS, Pires MM. Measurement of Small Molecule Accumulation into Diderm Bacteria. ACS Infect Dis 2023; 9:97-110. [PMID: 36530146 DOI: 10.1021/acsinfecdis.2c00435] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Some of the most dangerous bacterial pathogens (Gram-negative and mycobacterial) deploy a formidable secondary membrane barrier to reduce the influx of exogenous molecules. For Gram-negative bacteria, this second exterior membrane is known as the outer membrane (OM), while for the Gram-indeterminate Mycobacteria, it is known as the "myco" membrane. Although different in composition, both the OM and mycomembrane are key structures that restrict the passive permeation of small molecules into bacterial cells. Although it is well-appreciated that such structures are principal determinants of small molecule permeation, it has proven to be challenging to assess this feature in a robust and quantitative way or in complex, infection-relevant settings. Herein, we describe the development of the bacterial chloro-alkane penetration assay (BaCAPA), which employs the use of a genetically encoded protein called HaloTag, to measure the uptake and accumulation of molecules into model Gram-negative and mycobacterial species, Escherichia coli and Mycobacterium smegmatis, respectively, and into the human pathogen Mycobacterium tuberculosis. The HaloTag protein can be directed to either the cytoplasm or the periplasm of bacteria. This offers the possibility of compartmental analysis of permeation across individual cell membranes. Significantly, we also showed that BaCAPA can be used to analyze the permeation of molecules into host cell-internalized E. coli and M. tuberculosis, a critical capability for analyzing intracellular pathogens. Together, our results show that BaCAPA affords facile measurement of permeability across four barriers: the host plasma and phagosomal membranes and the diderm bacterial cell envelope.
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Affiliation(s)
- George M Ongwae
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Irene Lepori
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Mahendra D Chordia
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Brianna E Dalesandro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Alexis J Apostolos
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01003, United States.,Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Marcos M Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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17
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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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18
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Poulton NC, Rock JM. Unraveling the mechanisms of intrinsic drug resistance in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2022; 12:997283. [PMID: 36325467 PMCID: PMC9618640 DOI: 10.3389/fcimb.2022.997283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/30/2022] [Indexed: 02/03/2023] Open
Abstract
Tuberculosis (TB) is among the most difficult infections to treat, requiring several months of multidrug therapy to produce a durable cure. The reasons necessitating long treatment times are complex and multifactorial. However, one major difficulty of treating TB is the resistance of the infecting bacterium, Mycobacterium tuberculosis (Mtb), to many distinct classes of antimicrobials. This review will focus on the major gaps in our understanding of intrinsic drug resistance in Mtb and how functional and chemical-genetics can help close those gaps. A better understanding of intrinsic drug resistance will help lay the foundation for strategies to disarm and circumvent these mechanisms to develop more potent antitubercular therapies.
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19
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Lee IK, Jacome DA, Cho JK, Tu V, Young AJ, Dominguez T, Northrup JD, Etersque JM, Lee HS, Ruff A, Aklilu O, Bittinger K, Glaser LJ, Dorgan D, Hadjiliadis D, Kohli RM, Mach RH, Mankoff DA, Doot RK, Sellmyer MA. Imaging sensitive and drug-resistant bacterial infection with [11C]-trimethoprim. J Clin Invest 2022; 132:156679. [PMID: 36106638 PMCID: PMC9479701 DOI: 10.1172/jci156679] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 07/19/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Several molecular imaging strategies can identify bacterial infections in humans. PET affords the potential for sensitive infection detection deep within the body. Among PET-based approaches, antibiotic-based radiotracers, which often target key bacterial-specific enzymes, have considerable promise. One question for antibiotic radiotracers is whether antimicrobial resistance (AMR) reduces specific accumulation within bacteria, diminishing the predictive value of the diagnostic test. METHODS Using a PET radiotracer based on the antibiotic trimethoprim (TMP), [11C]-TMP, we performed in vitro uptake studies in susceptible and drug-resistant bacterial strains and whole-genome sequencing (WGS) in selected strains to identify TMP resistance mechanisms. Next, we queried the NCBI database of annotated bacterial genomes for WT and resistant dihydrofolate reductase (DHFR) genes. Finally, we initiated a first-in-human protocol of [11C]-TMP in patients infected with both TMP-sensitive and TMP-resistant organisms to demonstrate the clinical feasibility of the tool. RESULTS We observed robust [11C]-TMP uptake in our panel of TMP-sensitive and -resistant bacteria, noting relatively variable and decreased uptake in a few strains of P. aeruginosa and E. coli. WGS showed that the vast majority of clinically relevant bacteria harbor a WT copy of DHFR, targetable by [11C]-TMP, and that despite the AMR, these strains should be “imageable.” Clinical imaging of patients with [11C]-TMP demonstrated focal radiotracer uptake in areas of infectious lesions. CONCLUSION This work highlights an approach to imaging bacterial infection in patients, which could affect our understanding of bacterial pathogenesis as well as our ability to better diagnose infections and monitor response to therapy. TRIAL REGISTRATION ClinicalTrials.gov NCT03424525. FUNDING Institute for Translational Medicine and Therapeutics, Burroughs Wellcome Fund, NIH Office of the Director Early Independence Award (DP5-OD26386), and University of Pennsylvania NIH T32 Radiology Research Training Grant (5T32EB004311-12).
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Affiliation(s)
- Iris K. Lee
- Department of Radiology and
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | - Vincent Tu
- Department of Gastroenterology, Hepatology and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | | | | | | - Jean M. Etersque
- Department of Radiology and
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | - Kyle Bittinger
- Department of Gastroenterology, Hepatology and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Laurel J. Glaser
- Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel Dorgan
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, and
| | - Denis Hadjiliadis
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, and
| | - Rahul M. Kohli
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Division of Infectious Disease, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | - Mark A. Sellmyer
- Department of Radiology and
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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20
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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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21
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Li S, Poulton NC, Chang JS, Azadian ZA, DeJesus MA, Ruecker N, Zimmerman MD, Eckartt KA, Bosch B, Engelhart CA, Sullivan DF, Gengenbacher M, Dartois VA, Schnappinger D, Rock JM. CRISPRi chemical genetics and comparative genomics identify genes mediating drug potency in Mycobacterium tuberculosis. Nat Microbiol 2022; 7:766-779. [PMID: 35637331 PMCID: PMC9159947 DOI: 10.1038/s41564-022-01130-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/21/2022] [Indexed: 12/14/2022]
Abstract
Mycobacterium tuberculosis (Mtb) infection is notoriously difficult to treat. Treatment efficacy is limited by Mtb's intrinsic drug resistance, as well as its ability to evolve acquired resistance to all antituberculars in clinical use. A deeper understanding of the bacterial pathways that influence drug efficacy could facilitate the development of more effective therapies, identify new mechanisms of acquired resistance, and reveal overlooked therapeutic opportunities. Here we developed a CRISPR interference chemical-genetics platform to titrate the expression of Mtb genes and quantify bacterial fitness in the presence of different drugs. We discovered diverse mechanisms of intrinsic drug resistance, unveiling hundreds of potential targets for synergistic drug combinations. Combining chemical genetics with comparative genomics of Mtb clinical isolates, we further identified several previously unknown mechanisms of acquired drug resistance, one of which is associated with a multidrug-resistant tuberculosis outbreak in South America. Lastly, we found that the intrinsic resistance factor whiB7 was inactivated in an entire Mtb sublineage endemic to Southeast Asia, presenting an opportunity to potentially repurpose the macrolide antibiotic clarithromycin to treat tuberculosis. This chemical-genetic map provides a rich resource to understand drug efficacy in Mtb and guide future tuberculosis drug development and treatment.
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Affiliation(s)
- Shuqi Li
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Nicholas C Poulton
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Jesseon S Chang
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Zachary A Azadian
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Michael A DeJesus
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Nadine Ruecker
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Matthew D Zimmerman
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
| | - Kathryn A Eckartt
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Barbara Bosch
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Curtis A Engelhart
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Daniel F Sullivan
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Martin Gengenbacher
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
- Hackensack Meridian School of Medicine, Hackensack Meridian Health, Nutley, NJ, USA
| | - Véronique A Dartois
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
- Hackensack Meridian School of Medicine, Hackensack Meridian Health, Nutley, NJ, USA
| | - Dirk Schnappinger
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Jeremy M Rock
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA.
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22
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Leus IV, Weeks JW, Bonifay V, Shen Y, Yang L, Cooper CJ, Nash D, Duerfeldt AS, Smith JC, Parks JM, Rybenkov VV, Zgurskaya HI. Property space mapping of Pseudomonas aeruginosa permeability to small molecules. Sci Rep 2022; 12:8220. [PMID: 35581346 PMCID: PMC9114115 DOI: 10.1038/s41598-022-12376-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/10/2022] [Indexed: 02/03/2023] Open
Abstract
Two membrane cell envelopes act as selective permeability barriers in Gram-negative bacteria, protecting cells against antibiotics and other small molecules. Significant efforts are being directed toward understanding how small molecules permeate these barriers. In this study, we developed an approach to analyze the permeation of compounds into Gram-negative bacteria and applied it to Pseudomonas aeruginosa, an important human pathogen notorious for resistance to multiple antibiotics. The approach uses mass spectrometric measurements of accumulation of a library of structurally diverse compounds in four isogenic strains of P. aeruginosa with varied permeability barriers. We further developed a machine learning algorithm that generates a deterministic classification model with minimal synonymity between the descriptors. This model predicted good permeators into P. aeruginosa with an accuracy of 89% and precision above 58%. The good permeators are broadly distributed in the property space and can be mapped to six distinct regions representing diverse chemical scaffolds. We posit that this approach can be used for more detailed mapping of the property space and for rational design of compounds with high Gram-negative permeability.
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Affiliation(s)
- Inga V Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Jon W Weeks
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Vincent Bonifay
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Yue Shen
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Liang Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Connor J Cooper
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Dinesh Nash
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Adam S Duerfeldt
- Department of Medicinal Chemistry, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN, 55414, USA
| | - Jeremy C Smith
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Valentin V Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA.
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA.
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23
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Gurvic D, Leach AG, Zachariae U. Data-Driven Derivation of Molecular Substructures That Enhance Drug Activity in Gram-Negative Bacteria. J Med Chem 2022; 65:6088-6099. [PMID: 35427114 PMCID: PMC9059115 DOI: 10.1021/acs.jmedchem.1c01984] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The complex cell
envelope of Gram-negative bacteria creates a formidable
barrier to antibiotic influx. Reduced drug uptake impedes drug development
and contributes to a wide range of drug-resistant bacterial infections,
including those caused by extremely resistant species prioritized
by the World Health Organization. To develop new and efficient treatments,
a better understanding of the molecular features governing Gram-negative
permeability is essential. Here, we present a data-driven approach,
using matched molecular pair analysis and machine learning on minimal
inhibitory concentration data from Gram-positive and Gram-negative
bacteria to uncover chemical features that influence Gram-negative
bioactivity. We find recurring chemical moieties, of a wider range
than previously known, that consistently improve activity and suggest
that this insight can be used to optimize compounds for increased
Gram-negative uptake. Our findings may help to expand the chemical
space of broad-spectrum antibiotics and aid the search for new antibiotic
compound classes.
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Affiliation(s)
- Dominik Gurvic
- Computational Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom
| | - Andrew G. Leach
- Division of Pharmacy and Optometry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- Medchemica Limited, Mereside, Alderley Park, Macclesfield, SK10 4TG, United Kingdom
| | - Ulrich Zachariae
- Computational Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom
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24
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Gervasoni S, Malloci G, Bosin A, Vargiu AV, Zgurskaya HI, Ruggerone P. AB-DB: Force-Field parameters, MD trajectories, QM-based data, and Descriptors of Antimicrobials. Sci Data 2022; 9:148. [PMID: 35365662 PMCID: PMC8976083 DOI: 10.1038/s41597-022-01261-1] [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: 12/21/2021] [Accepted: 03/11/2022] [Indexed: 12/13/2022] Open
Abstract
Antibiotic resistance is a major threat to public health. The development of chemo-informatic tools to guide medicinal chemistry campaigns in the efficint design of antibacterial libraries is urgently needed. We present AB-DB, an open database of all-atom force-field parameters, molecular dynamics trajectories, quantum-mechanical properties, and curated physico-chemical descriptors of antimicrobial compounds. We considered more than 300 molecules belonging to 25 families that include the most relevant antibiotic classes in clinical use, such as β-lactams and (fluoro)quinolones, as well as inhibitors of key bacterial proteins. We provide traditional descriptors together with properties obtained with Density Functional Theory calculations. Noteworthy, AB-DB contains less conventional descriptors extracted from μs-long molecular dynamics simulations in explicit solvent. In addition, for each compound we make available force-field parameters for the major micro-species at physiological pH. With the rise of multi-drug-resistant pathogens and the consequent need for novel antibiotics, inhibitors, and drug re-purposing strategies, curated databases containing reliable and not straightforward properties facilitate the integration of data mining and statistics into the discovery of new antimicrobials. Measurement(s) | molecular physical property analysis objective | Technology Type(s) | Computer Modeling |
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Affiliation(s)
- Silvia Gervasoni
- University of Cagliari, Department of Physics, I-09042, Monserrato (Cagliari), Italy
| | - Giuliano Malloci
- University of Cagliari, Department of Physics, I-09042, Monserrato (Cagliari), Italy.
| | - Andrea Bosin
- University of Cagliari, Department of Physics, I-09042, Monserrato (Cagliari), Italy
| | - Attilio V Vargiu
- University of Cagliari, Department of Physics, I-09042, Monserrato (Cagliari), Italy
| | - Helen I Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, Norman, OK, 73072, United States
| | - Paolo Ruggerone
- University of Cagliari, Department of Physics, I-09042, Monserrato (Cagliari), Italy
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25
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Bozlul Karim M, Kanaya S, Altaf-Ul-Amin M. Antibacterial Activity Prediction of Plant Secondary Metabolites Based on a Combined Approach of Graph Clustering and Deep Neural Network. Mol Inform 2022; 41:e2100247. [PMID: 35014190 PMCID: PMC9400908 DOI: 10.1002/minf.202100247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/09/2022] [Indexed: 11/20/2022]
Abstract
The plants produce numerous types of secondary metabolites which have pharmacological importance in drug development for different diseases. Computational methods widely use the fingerprints of the metabolites to understand different properties and similarities among metabolites and for the prediction of chemical reactions etc. In this work, we developed three different deep neural network models (DNN) to predict the antibacterial property of plant metabolites. We developed the first DNN model using the fingerprint set of metabolites as features. In the second DNN model, we searched the similarities among fingerprints using correlation and used one representative feature from each group of highly correlated fingerprints. In the third model, the fingerprints of metabolites were used to find structurally similar chemical compound clusters. Form each cluster a representative metabolite is selected and made part of the training dataset. The second model reduced the number of features where the third model achieved better classification results for test data. In both cases, we applied the simple graph clustering method to cluster the corresponding network. The correlation‐based DNN model reduced some features while retaining an almost similar performance compared to the first DNN model. The third model improves classification results for test data by capturing wider variance within training data using graph clustering method. This third model is somewhat novel approach and can be applied to build DNN models for other purposes.
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26
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Abutaleb NS, Elhassanny AEM, Nocentini A, Hewitt CS, Elkashif A, Cooper BR, Supuran CT, Seleem MN, Flaherty DP. Repurposing FDA-approved sulphonamide carbonic anhydrase inhibitors for treatment of Neisseria gonorrhoeae. J Enzyme Inhib Med Chem 2021; 37:51-61. [PMID: 34894972 PMCID: PMC8667909 DOI: 10.1080/14756366.2021.1991336] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Neisseria gonorrhoeae is a high-priority pathogen of concern due to the growing prevalence of resistance development against approved antibiotics. Herein, we report the anti-gonococcal activity of ethoxzolamide, the FDA-approved human carbonic anhydrase inhibitor. Ethoxzolamide displayed an MIC50, against a panel of N. gonorrhoeae isolates, of 0.125 µg/mL, 16-fold more potent than acetazolamide, although both molecules exhibited almost similar potency against the gonococcal carbonic anhydrase enzyme (NgCA) in vitro. Acetazolamide displayed an inhibition constant (Ki) versus NgCA of 74 nM, while Ethoxzolamide’s Ki was estimated to 94 nM. Therefore, the increased anti-gonococcal potency of ethoxzolamide was attributed to its increased permeability in N. gonorrhoeae as compared to that of acetazolamide. Both drugs demonstrated bacteriostatic activity against N. gonorrhoeae, exhibited post-antibiotic effects up to 10 hours, and resistance was not observed against both. Taken together, these results indicate that acetazolamide and ethoxzolamide warrant further investigation for translation into effective anti-N. gonorrhoeae agents.
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Affiliation(s)
- Nader S Abutaleb
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VI, USA
| | - Ahmed E M Elhassanny
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VI, USA
| | - Alessio Nocentini
- Department of NEUROFARBA, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Polo Scientifico, Firenze, Italy
| | - Chad S Hewitt
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, USA
| | - Ahmed Elkashif
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
| | - Bruce R Cooper
- Metabolite Profiling Facility, Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States
| | - Claudiu T Supuran
- Department of NEUROFARBA, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Polo Scientifico, Firenze, Italy
| | - Mohamed N Seleem
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VI, USA.,Center for Emerging, Zoonotic and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, VI, USA
| | - Daniel P Flaherty
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, USA.,Purdue Institute for Drug Discovery, West Lafayette, IN, USA.,Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, IN, USA
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27
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Roy S, Bahar AA, Gu H, Nangia S, Sauer K, Ren D. Persister control by leveraging dormancy associated reduction of antibiotic efflux. PLoS Pathog 2021; 17:e1010144. [PMID: 34890435 PMCID: PMC8716142 DOI: 10.1371/journal.ppat.1010144] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/29/2021] [Accepted: 11/24/2021] [Indexed: 11/19/2022] Open
Abstract
Persistent bacterial infections do not respond to current antibiotic treatments and thus present a great medical challenge. These conditions have been linked to the formation of dormant subpopulations of bacteria, known as persister cells, that are growth-arrested and highly tolerant to conventional antibiotics. Here, we report a new strategy of persister control and demonstrate that minocycline, an amphiphilic antibiotic that does not require active transport to penetrate bacterial membranes, is effective in killing Escherichia coli persister cells [by 70.8 ± 5.9% (0.53 log) at 100 μg/mL], while being ineffective in killing normal cells. Further mechanistic studies revealed that persister cells have reduced drug efflux and accumulate more minocycline than normal cells, leading to effective killing of this dormant subpopulation upon wake-up. Consistently, eravacycline, which also targets the ribosome but has a stronger binding affinity than minocycline, kills persister cells by 3 logs when treated at 100 μg/mL. In summary, the findings of this study reveal that while dormancy is a well-known cause of antibiotic tolerance, it also provides an Achilles’ heel for controlling persister cells by leveraging dormancy associated reduction of drug efflux. Bacterial persister cells are dormant phenotypic variants that are highly tolerant to most antibiotics; and thus, present a major challenge to infection control. This motivated us to develop new strategies that can specifically target the persister population. It is known that persister formation is associated with reduced membrane potential and cellular activities. Thus, we hypothesize that persister cells have reduced drug efflux compared to normal cells and accumulate more antimicrobial agents that can penetrate the membranes of persister cells. By testing this hypothesis, we developed a new set of criteria for selecting persister control agents and demonstrated effective control of Escherichia coli persister cells by minocycline, rifamycin SV, and eravacycline. Our results revealed that these agents are more effective against persister cells than normal cells and the killing occurred during persister wake-up. Collectively, these results demonstrate a new strategy for persister control by leveraging dormancy associated changes in bacterial physiology. The findings may contribute to future drug discovery and the treatment of persistent infections.
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Affiliation(s)
- Sweta Roy
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York, United States of America
| | - Ali Adem Bahar
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York, United States of America
| | - Huan Gu
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York, United States of America
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York, United States of America
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, New York, United States of America
| | - Dacheng Ren
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York, United States of America
- Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York, United States of America
- Department of Biology, Syracuse University, Syracuse, New York, United States of America
- * E-mail:
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28
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Ishikawa F, Konno S, Takashima K, Kakeya H, Tanabe G. Inhibition of efflux pumps aids small-molecule probe-based fluorescence labeling and imaging in the Gram-negative bacterium Escherichia coli. Org Biomol Chem 2021; 19:8906-8911. [PMID: 34704577 DOI: 10.1039/d1ob01112j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A major challenge in fluorescence imaging experiments, which are essential to determine protein activity, expression, and localization, is the penetration of small-molecule probes through the outer membrane permeability barrier of bacteria. Here, we describe a novel strategy for small-molecule probe-based fluorescence protein labeling and imaging in the Gram-negative bacterium Escherichia coli. We targeted a siderophore enterobactin biosynthetic enzyme EntE in E. coli. When coupled with an efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone, small-molecule probes were able to efficiently enter the cells, leading to the fluorescence labeling and imaging of overproduced EntE in E. coli. This study demonstrates that the combination of small-molecule probes with appropriate efflux pump inhibitors may substantially enhance their interaction with the target proteins in live bacteria.
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Affiliation(s)
- Fumihiro Ishikawa
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
| | - Sho Konno
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Katsuki Takashima
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
| | - Hideaki Kakeya
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Genzoh Tanabe
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
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29
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Geddes EJ, Li Z, Hergenrother PJ. An LC-MS/MS assay and complementary web-based tool to quantify and predict compound accumulation in E. coli. Nat Protoc 2021; 16:4833-4854. [PMID: 34480129 PMCID: PMC8715754 DOI: 10.1038/s41596-021-00598-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 06/25/2021] [Indexed: 02/08/2023]
Abstract
Novel classes of broad-spectrum antibiotics have been extremely difficult to discover, largely due to the impermeability of the Gram-negative membranes coupled with a poor understanding of the physicochemical properties a compound should possess to promote its accumulation inside the cell. To address this challenge, numerous methodologies for assessing intracellular compound accumulation in Gram-negative bacteria have been established, including classic radiometric and fluorescence-based methods. The recent development of accumulation assays that utilize liquid chromatography-tandem mass spectrometry (LC-MS/MS) have circumvented the requirement for labeled compounds, enabling assessment of a substantially broader range of small molecules. Our unbiased study of accumulation trends in Escherichia coli using an LC-MS/MS-based assay led to the development of the eNTRy rules, which stipulate that a compound is most likely to accumulate in E. coli if it has an ionizable Nitrogen, has low Three-dimensionality and is relatively Rigid. To aid in the implementation of the eNTRy rules, we developed a complementary web tool, eNTRyway, which calculates relevant properties and predicts compound accumulation. Here we provide a comprehensive protocol for analysis and prediction of intracellular accumulation of small molecules in E. coli using an LC-MS/MS-based assay (which takes ~2 d) and eNTRyway, a workflow that is readily adoptable by any microbiology, biochemistry or chemical biology laboratory.
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Affiliation(s)
- Emily J Geddes
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Zhong Li
- Metabolomics Lab, Roy J. Carver Biotechnology Center, University of Illinois, Urbana, IL, USA
| | - Paul J Hergenrother
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL, USA.
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA.
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30
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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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31
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Rasmussen HB, Jürgens G, Thomsen R, Taboureau O, Zeth K, Hansen PE, Hansen PR. Cellular Uptake and Intracellular Phosphorylation of GS-441524: Implications for Its Effectiveness against COVID-19. Viruses 2021; 13:v13071369. [PMID: 34372575 PMCID: PMC8310262 DOI: 10.3390/v13071369] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/27/2021] [Accepted: 07/07/2021] [Indexed: 12/22/2022] Open
Abstract
GS-441524 is an adenosine analog and the parent nucleoside of the prodrug remdesivir, which has received emergency approval for treatment of COVID-19. Recently, GS-441524 has been proposed to be effective in the treatment of COVID-19, perhaps even being superior to remdesivir for treatment of this disease. Evaluation of the clinical effectiveness of GS-441524 requires understanding of its uptake and intracellular conversion to GS-441524 triphosphate, the active antiviral substance. We here discuss the potential impact of these pharmacokinetic steps of GS-441524 on the formation of its active antiviral substance and effectiveness for treatment of COVID-19. Available protein expression data suggest that several adenosine transporters are expressed at only low levels in the epithelial cells lining the alveoli in the lungs, i.e., the alveolar cells or pneumocytes from healthy lungs. This may limit uptake of GS-441524. Importantly, cellular uptake of GS-441524 may be reduced during hypoxia and inflammation due to decreased expression of adenosine transporters. Similarly, hypoxia and inflammation may lead to reduced expression of adenosine kinase, which is believed to convert GS-441524 to GS-441524 monophosphate, the perceived rate-limiting step in the intracellular formation of GS-441524 triphosphate. Moreover, increases in extracellular and intracellular levels of adenosine, which may occur during critical illnesses, has the potential to competitively decrease cellular uptake and phosphorylation of GS-441524. Taken together, tissue hypoxia and severe inflammation in COVID-19 may lead to reduced uptake and phosphorylation of GS-441524 with lowered therapeutic effectiveness as a potential outcome. Hypoxia may be particularly critical to the ability of GS-441524 to eliminate SARS-CoV-2 from tissues with low basal expression of adenosine transporters, such as alveolar cells. This knowledge may also be relevant to treatments with other antiviral adenosine analogs and anticancer adenosine analogs as well.
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Affiliation(s)
- Henrik Berg Rasmussen
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, DK-4000 Roskilde, Denmark
- Department of Science and Environment, Roskilde University Center, DK-4000 Roskilde, Denmark; (K.Z.); (P.E.H.)
- Correspondence:
| | - Gesche Jürgens
- Clinical Pharmacology Unit, Zealand University Hospital, DK-4000 Roskilde, Denmark;
| | - Ragnar Thomsen
- Section of Forensic Chemistry, Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark;
| | - Olivier Taboureau
- INSERM U1133, CNRS UMR 8251, Université de Paris, F-75013 Paris, France;
| | - Kornelius Zeth
- Department of Science and Environment, Roskilde University Center, DK-4000 Roskilde, Denmark; (K.Z.); (P.E.H.)
| | - Poul Erik Hansen
- Department of Science and Environment, Roskilde University Center, DK-4000 Roskilde, Denmark; (K.Z.); (P.E.H.)
| | - Peter Riis Hansen
- Department of Cardiology, Herlev and Gentofte Hospital, DK-2900 Hellerup, Denmark;
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32
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Golubchik A, Lopes LC, Singh V, Kuss S. Pharma‐molecule Transport across Bacterial Membranes: Detection and Quantification Approaches by Electrochemistry and Bioanalytical Methods. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alon Golubchik
- Department Chemistry University of Manitoba Winnipeg R3T 2N2 Canada
| | | | - Vikram Singh
- Department Chemistry University of Manitoba Winnipeg R3T 2N2 Canada
| | - Sabine Kuss
- Department Chemistry University of Manitoba Winnipeg R3T 2N2 Canada
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33
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Ishikawa F, Konno S, Uchida C, Suzuki T, Takashima K, Dohmae N, Kakeya H, Tanabe G. Chemoproteomics profiling of surfactin-producing nonribosomal peptide synthetases in living bacterial cells. Cell Chem Biol 2021; 29:145-156.e8. [PMID: 34133952 DOI: 10.1016/j.chembiol.2021.05.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/06/2021] [Accepted: 05/26/2021] [Indexed: 01/09/2023]
Abstract
Much of our current knowledge on nonribosomal peptide synthetases (NRPSs) is based on studies in which the full NRPS system or each protein domain is expressed in heterologous hosts. Consequently, methods to detect the endogenous activity of NRPSs, under natural cellular conditions, are needed for the study of NRPS cell biology. Here, we describe the in vivo activity-based protein profiling (ABPP) for endogenous NRPSs and its applications to the study of their activities in bacteria. Remarkably, in vitro and in vivo ABPP in the context of the surfactin producer Bacillus subtilis enabled the visualization, tracking, and imaging of an endogenous SrfAB-NRPS with remarkable selectivity and sensitivity. Furthermore, in vivo, ABPP allowed the discovery of the degradation processes of the endogenous SrfAB-NRPS in the context of its native producer bacteria. Overall, this study deepens our understanding of the properties of NRPSs that cannot be addressed by conventional methods.
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Affiliation(s)
- Fumihiro Ishikawa
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
| | - Sho Konno
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Chiharu Uchida
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Katsuki Takashima
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hideaki Kakeya
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Genzoh Tanabe
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
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34
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Golubchik A, Lopes LC, Singh V, Kuss S. Pharma-molecule Transport across Bacterial Membranes: Detection and Quantification Approaches by Electrochemistry and Bioanalytical Methods. Angew Chem Int Ed Engl 2021; 60:22112-22124. [PMID: 33979000 DOI: 10.1002/anie.202101055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Indexed: 11/07/2022]
Abstract
Antibiotic resistance is a significant challenge encountered by healthcare systems on a global scale. Knowledge about membrane transport of antibiotics and other pharmacologically relevant molecules in bacteria is crucial towards understanding and overcoming antibiotic resistance, as drug resistance often depends on drug transport. This comprehensive literature review discusses the detection and quantification of membrane transport of pharma-molecules in bacteria and highlights the importance of molecule transport to antibiotic resistance. This review emphasizes electrochemical and electrophysiological methods of detection and quantification. The results of this literature review reveal a substantial diversity in methods and types of quantitative information collected.
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Affiliation(s)
- Alon Golubchik
- Department Chemistry, University of Manitoba, Winnipeg, R3T 2N2, Canada
| | | | - Vikram Singh
- Department Chemistry, University of Manitoba, Winnipeg, R3T 2N2, Canada
| | - Sabine Kuss
- Department Chemistry, University of Manitoba, Winnipeg, R3T 2N2, Canada
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Prajapati JD, Kleinekathöfer U, Winterhalter M. How to Enter a Bacterium: Bacterial Porins and the Permeation of Antibiotics. Chem Rev 2021; 121:5158-5192. [PMID: 33724823 DOI: 10.1021/acs.chemrev.0c01213] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Despite tremendous successes in the field of antibiotic discovery seen in the previous century, infectious diseases have remained a leading cause of death. More specifically, pathogenic Gram-negative bacteria have become a global threat due to their extraordinary ability to acquire resistance against any clinically available antibiotic, thus urging for the discovery of novel antibacterial agents. One major challenge is to design new antibiotics molecules able to rapidly penetrate Gram-negative bacteria in order to achieve a lethal intracellular drug accumulation. Protein channels in the outer membrane are known to form an entry route for many antibiotics into bacterial cells. Up until today, there has been a lack of simple experimental techniques to measure the antibiotic uptake and the local concentration in subcellular compartments. Hence, rules for translocation directly into the various Gram-negative bacteria via the outer membrane or via channels have remained elusive, hindering the design of new or the improvement of existing antibiotics. In this review, we will discuss the recent progress, both experimentally as well as computationally, in understanding the structure-function relationship of outer-membrane channels of Gram-negative pathogens, mainly focusing on the transport of antibiotics.
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Affiliation(s)
| | | | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen 28759, Germany
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Muñoz KA, Hergenrother PJ. Facilitating Compound Entry as a Means to Discover Antibiotics for Gram-Negative Bacteria. Acc Chem Res 2021; 54:1322-1333. [PMID: 33635073 DOI: 10.1021/acs.accounts.0c00895] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
It has been over half a century since the last class of antibiotics active against the most problematic Gram-negative bacteria was approved by the Food and Drug Administration (FDA). The major challenge with developing antibiotics to treat these infections is not drug-target engagement but rather the inability of most small molecules to traverse the Gram-negative membranes, be retained, and accumulate within the cell. Despite an abundance of lead compounds, limited understanding of the physicochemical properties needed for compound accumulation (or avoidance of efflux) in Gram-negative bacteria has precluded a generalizable approach for developing Gram-negative antibiotics. Indeed, in many instances, despite years of intensive derivatization efforts and the synthesis of hundreds of compounds aimed at building in Gram-negative activity, little or no progress has been made in expanding the spectrum of activity for many Gram-positive-only antibiotics. In this Account, we describe the discovery and successful applications of a promising strategy for enhancing the accumulation of Gram-positive-only antibiotics as a means of imbuing compounds with broad-spectrum activity.Utilizing a prospective approach examining the accumulation in Escherichia coli for more than 180 diverse compounds, we found that small molecules have an increased likelihood to accumulate in E. coli when they contain an ionizable Nitrogen, have low Three-dimensionality, and are Rigid. Implementing these guidelines, codified as the "eNTRy rules" and assisted by web application www.entry-way.org, we have facilitated compound entry and systematically built Gram-negative activity into Gram-positive-only antibiotics. Though each antibiotic will have case-specific considerations, we describe a set of important criteria to consider when selecting candidate Gram-positive-only antibiotics for conversion to Gram-negative-active versions via the eNTRy rules. As detailed herein, using this blueprint the spectrum of activity was expanded for three antibiotic classes that engage three different biological targets: DNA gyrase inhibitor 6DNM, FabI inhibitor Debio-1452, and FMN riboswitch inhibitor Ribocil C. In each scenario, the eNTRy rules guided the synthesis of key analogues predisposed to accumulate in Gram-negative bacteria leading to compounds that display antibiotic activity (minimum inhibitory concentrations (MIC) ≤8 μg mL-1) against E. coli and other Gram-negative ESKAPE pathogens. While the eNTRy rules will continue to be refined and enhanced as more accumulation data is gathered, on the basis of these collective results and on other examples not covered herein it is clear that the eNTRy rules are actionable for the development of novel broad-spectrum antibiotics from Gram-positive-only compounds. By enabling the prediction of compound accumulation, the eNTRy rules should facilitate the process of discovering and developing novel antibiotics active against Gram-negative bacteria.
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Affiliation(s)
- Kristen A. Muñoz
- Department of Chemistry Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Paul J. Hergenrother
- Department of Chemistry Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Urbana, Illinois 61801, United States
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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: 58] [Impact Index Per Article: 14.5] [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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Stone MRL, Łapińska U, Pagliara S, Masi M, Blanchfield JT, Cooper MA, Blaskovich MAT. Fluorescent macrolide probes - synthesis and use in evaluation of bacterial resistance. RSC Chem Biol 2020; 1:395-404. [PMID: 34458770 PMCID: PMC8341779 DOI: 10.1039/d0cb00118j] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/28/2020] [Indexed: 12/19/2022] Open
Abstract
The emerging crisis of antibiotic resistance requires a multi-pronged approach in order to avert the onset of a post-antibiotic age. Studies of antibiotic uptake and localisation in live cells may inform the design of improved drugs and help develop a better understanding of bacterial resistance and persistence. To facilitate this research, we have synthesised fluorescent derivatives of the macrolide antibiotic erythromycin. These analogues exhibit a similar spectrum of antibiotic activity to the parent drug and are capable of labelling both Gram-positive and -negative bacteria for microscopy. The probes localise intracellularly, with uptake in Gram-negative bacteria dependent on the level of efflux pump activity. A plate-based assay established to quantify bacterial labelling and localisation demonstrated that the probes were taken up by both susceptible and resistant bacteria. Significant intra-strain and -species differences were observed in these preliminary studies. In order to examine uptake in real-time, the probe was used in single-cell microfluidic microscopy, revealing previously unseen heterogeneity of uptake in populations of susceptible bacteria. These studies illustrate the potential of fluorescent macrolide probes to characterise and explore drug uptake and efflux in bacteria. Macrolide fluorescent probes illuminate the interactions between antibiotics and bacteria, providing new insight into mechanisms of resistance.![]()
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Affiliation(s)
- M Rhia L Stone
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland 306 Carmody Road St Lucia 4072 Brisbane Australia
| | - Urszula Łapińska
- Living Systems Institute, University of Exeter Exeter EX4 4QD UK
| | - Stefano Pagliara
- Living Systems Institute, University of Exeter Exeter EX4 4QD UK
| | - Muriel Masi
- Université Paris-Saclay, CEA, CNRS Institute for Integrative Biology of the Cell (I2BC) 911198 Gif-sur-Yvette France
| | - Joanne T Blanchfield
- School of Chemistry and Molecular Biosciences, The University of Queensland 68 Cooper Road St Lucia 4072 Brisbane Australia
| | - Matthew A Cooper
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland 306 Carmody Road St Lucia 4072 Brisbane Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland 306 Carmody Road St Lucia 4072 Brisbane Australia
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Winterhalter M. Antibiotic uptake through porins located in the outer membrane of Gram-negative bacteria. Expert Opin Drug Deliv 2020; 18:449-457. [PMID: 33161750 DOI: 10.1080/17425247.2021.1847080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Introduction: Making selective inhibitors of novel Gram-negative targets is not a substantial challenge - getting them into Gram-negative bacteria to reach their lethal target is the bottleneck. Poor permeability of the antibiotic requires high concentration causing off target activity. The lack of simple experimental techniques to measure antibiotic uptake as well as the local concentration at the target site creates a particular bottleneck in understanding and in improving the antibiotic activity.Areas covered: Here we recall current approaches to quantify the uptake. For a few antibiotics with known evidence for channel-limited permeation, the flux across a single OmpF or OmpC channel has been measured. For a typical concentration gradient of 1 µM of antibiotics the uptake varies between one up to few hundred molecules per second and per channel.Expert opinion: The current research effort is on quantifying the flux for a larger list of compounds on a cellular (mass spectra, fluorescence) or at single channel level (electrophysiology). A larger dataset of single channel permeabilities under various condition will be a powerful tool for understanding and improving the activity of antibiotics.
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Pandeya A, Alegun O, Cai Y, Wei Y. Distribution of fluoroquinolones in the two aqueous compartments of Escherichia coli. Biochem Biophys Rep 2020; 24:100849. [PMID: 33235925 PMCID: PMC7670238 DOI: 10.1016/j.bbrep.2020.100849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 10/10/2020] [Accepted: 10/23/2020] [Indexed: 12/31/2022] Open
Abstract
The double-layered cell envelope of Gram-negative bacteria and active drug efflux present a formidable barrier for antimicrobial compounds to penetrate. Fluoroquinolones are among the few classes of antimicrobials that are clinically useful in the treatment of Gram-negative bacterial infection. Previous studies on fluoroquinolone accumulation measured total bacteria associated compounds, rather than the cytoplasmic accumulation. Fluoroquinolones target the type II topoisomerases in the cytoplasm. Thus, the cytoplasmic accumulation is expected to be more relevant to the potency of the drugs. Here, we fractionated and measured the concentration of nine fluoroquinolone compounds in the periplasm and the cytoplasm of two strains of E. coli cells, a parent strain and its isogenic efflux-deficient tolC knockout strain. The potency of the drugs was determined using the minimum inhibitory concentration (MIC) assay. We found that all fluoroquinolones tested accumulated at much higher concentrations in the periplasm than in the cytoplasm. The periplasmic concentrations were 2–15 folds higher than the cytoplasmic concentration, while the actual distribution ratio varies drastically among the compounds tested. Good correlation between the MIC and the cytoplasmic accumulation, but not whole cell accumulation, was observed using a pair of isogenic wild type and drug-efflux deficient strains. Fluoroquinolones accumulate to high concentration in the periplasm of E. coli Periplasmic concentrations are higher than the cytoplasmic and exterior media concentration. Good correlation was observed for the cytoplasmic drug concentration and the antimicrobial potency. Disruption of active efflux has a larger impact on the periplasmic than the cytoplasmic accumulation.
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Affiliation(s)
- Ankit Pandeya
- Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Olaniyi Alegun
- Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Yuguang Cai
- Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Yinan Wei
- Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA
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Ushiyama F, Amada H, Mihara Y, Takeuchi T, Tanaka-Yamamoto N, Mima M, Kamitani M, Wada R, Tamura Y, Endo M, Masuko A, Takata I, Hitaka K, Sugiyama H, Ohtake N. Lead optimization of 8-(methylamino)-2-oxo-1,2-dihydroquinolines as bacterial type II topoisomerase inhibitors. Bioorg Med Chem 2020; 28:115776. [PMID: 33032189 DOI: 10.1016/j.bmc.2020.115776] [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] [Received: 07/09/2020] [Revised: 09/13/2020] [Accepted: 09/15/2020] [Indexed: 11/28/2022]
Abstract
The global increase in multidrug-resistant pathogens has caused severe problems in the treatment of infections. To overcome these difficulties, the advent of a new chemical class of antibacterial drug is eagerly desired. We aimed at creating novel antibacterial agents against bacterial type II topoisomerases, which are well-validated targets. TP0480066 (compound 32) has been identified by using structure-based optimization originated from lead compound 1, which was obtained as a result of our previous lead identification studies. The MIC90 values of TP0480066 against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), and genotype penicillin-resistant Streptococcus pneumoniae (gPRSP) were 0.25, 0.015, and 0.06 μg/mL, respectively. Hence, TP0480066 can be regarded as a promising antibacterial drug candidate of this chemical class.
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Affiliation(s)
- Fumihito Ushiyama
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan.
| | - Hideaki Amada
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Yasuhiro Mihara
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Tomoki Takeuchi
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | | | - Masashi Mima
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Masafumi Kamitani
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Reiko Wada
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Yunoshin Tamura
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Mayumi Endo
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Aiko Masuko
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Iichiro Takata
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Kosuke Hitaka
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Hiroyuki Sugiyama
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
| | - Norikazu Ohtake
- Taisho Pharmaceutical Co., Ltd, 1-403 Yoshino-Cho, Kita-Ku, Saitama 331-9530, Japan
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Lu X, Zhang Z, Xu Y, Lu J, Tang W, Zhang J. Effect of new carbonyl cyanide aromatic hydrazones on biofilm inhibition against methicillin resistant Staphylococcus aureus. RSC Adv 2020; 10:17854-17861. [PMID: 35515581 PMCID: PMC9053579 DOI: 10.1039/d0ra03124k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 04/29/2020] [Indexed: 12/03/2022] Open
Abstract
Carbonyl cyanide m-chlorophenylhydrazone (CCCP), as a protonophore, in combination with antibiotics exhibited potentiating antibacterial activity. To improve CCCP's potency and toxicity, a series of aromatic hydrazones were synthesized and their antimicrobial activity was evaluated; amongst them, compounds 2e and 2j with a strong para-electron-withdrawing substituent (–NO2 and –CF3) at the phenyl ring had the lowest MICs against both S. aureus and methicillin resistant Staphylococcus aureus (1.56 and 1.56 μM, respectively). Some compounds in combination with antibiotics exhibited potentiate Gram-positive antibacterial activity; compound 2e was found to display unaided or synergistic efficacy against MRSA. In particular, when compound 2e is combined with ofloxacin, it has a good synergistic effect against MRSA. Moreover, electron microscopy revealed that compound 2e inhibits biofilm formation and effectively eradicates preformed biofilm. MTT assay showed that compound 2e displays as low toxicity as CCCP. Overall, our data showed that the aromatic hydrazone is a promising scaffold for anti-staphylococcal drug development. 2e and 2j with strong p-NO2 and p-CF3 at phenyl ring had the lowest MICs against S. aureus and MRSA. 2e displayed unaided or synergistic efficacy against MRSA, especially combined with ofloxacin. EM revealed that 2e destroys biofilms and cell membranes.![]()
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Affiliation(s)
- Xueer Lu
- School of Medicine, Anhui University of Science and Technology Huainan 232001 China.,Anhui Prevention and Treatment Center for Occupational Disease, Anhui No. 2 Provincial People's Hospital Hefei 230041 China
| | - Ziwen Zhang
- School of Pharmacy, Anhui Medical University Hefei 230032 China
| | - Yingying Xu
- School of Pharmacy, Anhui Medical University Hefei 230032 China
| | - Jun Lu
- School of Medicine, Anhui University of Science and Technology Huainan 232001 China
| | - Wenjian Tang
- School of Pharmacy, Anhui Medical University Hefei 230032 China
| | - Jing Zhang
- School of Medicine, Anhui University of Science and Technology Huainan 232001 China.,Anhui Prevention and Treatment Center for Occupational Disease, Anhui No. 2 Provincial People's Hospital Hefei 230041 China
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McDowell LL, Quinn CL, Leeds JA, Silverman JA, Silver LL. Perspective on Antibacterial Lead Identification Challenges and the Role of Hypothesis-Driven Strategies. SLAS DISCOVERY 2020; 24:440-456. [PMID: 30890054 DOI: 10.1177/2472555218818786] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For the past three decades, the pharmaceutical industry has undertaken many diverse approaches to discover novel antibiotics, with limited success. We have witnessed and personally experienced many mistakes, hurdles, and dead ends that have derailed projects and discouraged scientists and business leaders. Of the many factors that affect the outcomes of screening campaigns, a lack of understanding of the properties that drive efflux and permeability requirements across species has been a major barrier for advancing hits to leads. Hits that possess bacterial spectrum have seldom also possessed druglike properties required for developability and safety. Persistence in solving these two key barriers is necessary for the reinvestment into discovering antibacterial agents. This perspective narrates our experience in antibacterial discovery-our lessons learned about antibacterial challenges as well as best practices for screening strategies. One of the tenets that guides us is that drug discovery is a hypothesis-driven science. Application of this principle, at all steps in the antibacterial discovery process, should improve decision making and possibly the odds of what has become, in recent decades, an increasingly challenging endeavor with dwindling success rates.
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Affiliation(s)
- Laura L McDowell
- 1 Novartis Institutes for Biomedical Research, Emeryville, CA, USA
| | | | - Jennifer A Leeds
- 1 Novartis Institutes for Biomedical Research, Emeryville, CA, USA
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Uriel C, Permingeat C, Ventura J, Avellanal-Zaballa E, Bañuelos J, García-Moreno I, Gómez AM, Lopez JC. BODIPYs as Chemically Stable Fluorescent Tags for Synthetic Glycosylation Strategies towards Fluorescently Labeled Saccharides. Chemistry 2020; 26:5388-5399. [PMID: 31999023 DOI: 10.1002/chem.201905780] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Indexed: 12/11/2022]
Abstract
A series of fluorescent boron-dipyrromethene (BODIPY, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes have been designed to participate, as aglycons, in synthetic oligosaccharide protocols. As such, they served a dual purpose: first, by being incorporated at the beginning of the process (at the reducing-end of the growing saccharide moiety), they can function as fluorescent glycosyl tags, facilitating the detection and purification of the desired glycosidic intermediates, and secondly, the presence of these chromophores on the ensuing compounds grants access to fluorescently labeled saccharides. In this context, a sought-after feature of the fluorescent dyes has been their chemical robustness. Accordingly, some BODIPY derivatives described in this work can withstand the reaction conditions commonly employed in the chemical synthesis of saccharides; namely, glycosylation and protecting-group manipulations. Regarding their photophysical properties, the BODIPY-labeled saccharides obtained in this work display remarkable fluorescence efficiency in water, reaching quantum yield values up to 82 %, as well as notable lasing efficiencies and photostabilities.
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Affiliation(s)
- Clara Uriel
- Instituto de Química Organica General (IQOG-CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | - Caterina Permingeat
- Instituto de Química Organica General (IQOG-CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | - Juan Ventura
- Instituto de Química Organica General (IQOG-CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | | | - Jorge Bañuelos
- Dpto. Química Física, Universidad del País Vasco (UPV/EHU), Aptdo. 644, 48080, Bilbao, Spain
| | | | - Ana M Gómez
- Instituto de Química Organica General (IQOG-CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | - J Cristobal Lopez
- Instituto de Química Organica General (IQOG-CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
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Li Q, Yin L, Xue M, Wang Z, Song X, Shao Y, Liu H, Tu J, Qi K. The transcriptional regulator PhoP mediates the tolC molecular mechanism on APEC biofilm formation and pathogenicity. Avian Pathol 2020; 49:211-220. [PMID: 31809574 DOI: 10.1080/03079457.2019.1701182] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
As a transcriptional regulator of the classical binary regulatory system, PhoP plays an important role in the life activities of avian pathogenic Escherichia coli (APEC). In previous experiments, we found that the absence of phoP affects APEC biofilm formation and pathogenicity. To further explore the molecular mechanism of phoP regulation of these phenomena, the differentially expressed gene tolC was screened based on phoP-derived transcriptional data, and the specific sequence identity of the PhoP binding sequence was predicted by bioinformatics and verified by electrophoretic mobility shift assay (EMSA). The results showed that PhoP can directly bind to the tolC promoter. On this basis, tolC deletion and complementary strains were constructed. Biofilm formation was quantified by crystal violet staining and rdar morphology change was observed in these strains. Loss of tolC reduced biofilm formation. We also examined pathological changes in organ paraffin sections by challenging chicks with the strains. After loss of tolC, the clinical signs of pericarditis and liver and spleen enlargement in chicks were alleviated, and pathogenicity to the host cells was decreased. Additionally, quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that tolC deletion downregulated secA/secB/secE/secY transcript levels, which are part of the type II secretion system secreting virulence effector element. These results indicate that tolC contributes to the phoP-mediated effect on APEC biofilm formation and pathogenicity.
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Affiliation(s)
- Qianwen Li
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Lei Yin
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Mei Xue
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Zeping Wang
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Xiangjun Song
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Yin Shao
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Hongmei Liu
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Jian Tu
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China
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46
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Sarkar A. Enabling design of screening libraries for antibiotic discovery by modeling ChEMBL data. Eur J Pharm Sci 2020; 143:105166. [PMID: 31783159 DOI: 10.1016/j.ejps.2019.105166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/11/2019] [Accepted: 11/24/2019] [Indexed: 11/17/2022]
Abstract
It is critical to identify novel antibiotics. Yet, the scientific community has struggled in this pursuit because we do not understand which molecules will penetrate the bacterial outer envelope. In this work, we have identified a large dataset of compounds known to reach their targets in bacterial cells (penetrators) and compared them with molecules that do not (non-penetrators). Our dataset, extracted from the ChEMBL database, is a useful tool to guide the selection of molecules for antibiotic screening. Simple random forest classification models are able to correctly identify penetrators from non-penetrators. The model demonstrated ~87% accuracy, with high precision (~88%) and recall (~97%) in identifying penetrators of Gram-positive bacteria. A paucity of data for non-penetrators was a major hurdle to model-building; we observed a ~86% negative predictive value, but only a ~57% specificity. Accumulation of data on non-penetrators is therefore necessary. Data for Gram-negative bacteria was also sparse, but a larger fraction of these data represented non-penetrators. Correspondingly, the resultant models performed well in predicting those molecules that would fail to enter Gram-negative cells, but were relatively weaker in correctly predicting penetrators. A comparison of physicochemical properties of penetrators and non-penetrators suggests only marginal differences exist. Therefore, it may be difficult to identify overarching rules for generation of screening libraries for antibiotic discovery, based purely on physicochemical properties alone. Instead, models such as ours should be of use. Our models are highly preliminary and based on phenotypic data, but a similar large dataset directly addressing accumulation of chemical matter in bacterial cells is currently unavailable. Hence, our models represent the cutting edge in design of screening libraries for antibiotic discovery until appropriate data can be compiled.
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Affiliation(s)
- Aurijit Sarkar
- Department of Basic Pharmaceutical Sciences, Fred Wilson School of Pharmacy, High Point University, One University Pkwy, High Point NC 27268 USA.
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Detweiler CS. Infection-based chemical screens uncover host-pathogen interactions. Curr Opin Microbiol 2020; 54:43-50. [PMID: 32036306 DOI: 10.1016/j.mib.2019.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/30/2019] [Indexed: 12/12/2022]
Abstract
Bacterial pathogens must resist host innate immunity to cause disease. While Gram-negative bacteria have a protective outer membrane, this membrane is subject to host-induced damage that makes these pathogens vulnerable. We developed a high content screening platform that identifies compounds that cause the killing of the bacterial pathogen Salmonella enterica in macrophages. This platform enables the rapid discovery of compounds that work in concert with the macrophage to prevent pathogen survival, as most hit compounds are not active in standard microbiological media and are not pro-drugs. We describe within the platform and the compounds it has found, and consider how they may help us discover new ways to fight infection.
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Affiliation(s)
- Corrella S Detweiler
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, United States.
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Vickery CR, McCulloch IP, Sonnenschein EC, Beld J, Noel JP, Burkart MD. Dissecting modular synthases through inhibition: A complementary chemical and genetic approach. Bioorg Med Chem Lett 2020; 30:126820. [PMID: 31812466 DOI: 10.1016/j.bmcl.2019.126820] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 11/08/2019] [Accepted: 11/09/2019] [Indexed: 01/23/2023]
Abstract
Modular synthases, such as fatty acid, polyketide, and non-ribosomal peptide synthases (NRPSs), are sophisticated machineries essential in both primary and secondary metabolism. Various techniques have been developed to understand their genetic background and enzymatic abilities. However, uncovering the actual biosynthetic pathways remains challenging. Herein, we demonstrate a pipeline to study an assembly line synthase by interrogating the enzymatic function of each individual enzymatic domain of BpsA, a NRPS that produces the blue 3,3'-bipyridyl pigment indigoidine. Specific inhibitors for each biosynthetic domain of BpsA were obtained or synthesized, and the enzymatic performance of BpsA upon addition of each inhibitor was monitored by pigment development in vitro and in living bacteria. The results were verified using genetic mutants to inactivate each domain. Finally, the results complemented the currently proposed biosynthetic pathway of BpsA.
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Affiliation(s)
- Christopher R Vickery
- Department of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA; Howard Hughes Medical Institute, The Salk Institute for Biological Studies, Jack H. Skirball Center for Chemical Biology and Proteomics, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Ian P McCulloch
- Department of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA
| | - Eva C Sonnenschein
- Department of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA
| | - Joris Beld
- Department of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA
| | - Joseph P Noel
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, Jack H. Skirball Center for Chemical Biology and Proteomics, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA.
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Dumont E, Vergalli J, Conraux L, Taillier C, Vassort A, Pajovic J, Réfrégiers M, Mourez M, Pagès JM. Antibiotics and efflux: combined spectrofluorimetry and mass spectrometry to evaluate the involvement of concentration and efflux activity in antibiotic intracellular accumulation. J Antimicrob Chemother 2020; 74:58-65. [PMID: 30325444 DOI: 10.1093/jac/dky396] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 09/04/2018] [Indexed: 11/14/2022] Open
Abstract
Background In Gram-negative bacteria, passing through the double membrane barrier to reach the inhibitory concentration inside the bacterium is a pivotal step for antibiotic activity. Spectrofluorimetry has been developed to follow fluoroquinolone accumulation inside bacteria using intrinsic bacterial fluorescence as an internal standard. However, adaptation for non-fluorescent antibiotics is needed; quantitative methods based on MS offer the possibility of expanding the detection range obtained by spectrofluorimetry. Objectives To validate, with spectrofluorimetry, the use of MS to measure antibiotic accumulation in cells and to determine the relationship between antibiotic concentrations and the amount of intrabacterial accumulation in different efflux backgrounds on the same batch of molecules. Methods Spectrofluorimetry was performed in parallel with MS on the same samples to measure the ciprofloxacin and fleroxacin accumulation in cells expressing various efflux pump levels. A microplate protocol was set up to determine the antibiotic accumulation as a function of external antibiotic concentrations. Results A correlation existed between the data obtained with spectrofluorimetry and MS, whatever the efflux pump or tested antibiotic. The results highlighted different dynamics of uptake between ciprofloxacin and fleroxacin as well as the relationship between the level of efflux activity and antibiotic accumulation. Conclusions We have developed a microplate protocol and cross-validated two complementary methods: spectrofluorimetry, which contains a reliable internal standard; and MS, which allows detection of low antibiotic amounts. These assays allow study of the dose effect and the efflux impact on the intrabacterial accumulation of antibiotics.
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Affiliation(s)
- Estelle Dumont
- UMR_MD1, Aix-Marseille Univ, U-1261 INSERM, SSA, IRBA, MCT, Marseille, France
| | - Julia Vergalli
- UMR_MD1, Aix-Marseille Univ, U-1261 INSERM, SSA, IRBA, MCT, Marseille, France
| | - Laurence Conraux
- Infectious Diseases Therapeutic Area, Sanofi R&D, Marcy l'Étoile, France
| | - Carine Taillier
- Infectious Diseases Therapeutic Area, Sanofi R&D, Marcy l'Étoile, France
| | - Aurélie Vassort
- Infectious Diseases Therapeutic Area, Sanofi R&D, Marcy l'Étoile, France
| | | | | | - Michael Mourez
- Infectious Diseases Therapeutic Area, Sanofi R&D, Marcy l'Étoile, France
| | - Jean-Marie Pagès
- UMR_MD1, Aix-Marseille Univ, U-1261 INSERM, SSA, IRBA, MCT, Marseille, France
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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: 89] [Impact Index Per Article: 22.3] [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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