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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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2
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Hoffmann A, Steffens U, Maček B, Franz-Wachtel M, Nieselt K, Harbig TA, Scherlach K, Hertweck C, Sahl HG, Bierbaum G. The unusual mode of action of the polyketide glycoside antibiotic cervimycin C. mSphere 2024; 9:e0076423. [PMID: 38722162 DOI: 10.1128/msphere.00764-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/28/2024] [Indexed: 05/30/2024] Open
Abstract
Cervimycins A-D are bis-glycosylated polyketide antibiotics produced by Streptomyces tendae HKI 0179 with bactericidal activity against Gram-positive bacteria. In this study, cervimycin C (CmC) treatment caused a spaghetti-like phenotype in Bacillus subtilis 168, with elongated curved cells, which stayed joined after cell division, and exhibited a chromosome segregation defect, resulting in ghost cells without DNA. Electron microscopy of CmC-treated Staphylococcus aureus (3 × MIC) revealed swollen cells, misshapen septa, cell wall thickening, and a rough cell wall surface. Incorporation tests in B. subtilis indicated an effect on DNA biosynthesis at high cervimycin concentrations. Indeed, artificial downregulation of the DNA gyrase subunit B gene (gyrB) increased the activity of cervimycin in agar diffusion tests, and, in high concentrations (starting at 62.5 × MIC), the antibiotic inhibited S. aureus DNA gyrase supercoiling activity in vitro. To obtain a more global view on the mode of action of CmC, transcriptomics and proteomics of cervimycin treated versus untreated S. aureus cells were performed. Interestingly, 3 × MIC of cervimycin did not induce characteristic responses, which would indicate disturbance of the DNA gyrase activity in vivo. Instead, cervimycin induced the expression of the CtsR/HrcA heat shock operon and the expression of autolysins, exhibiting similarity to the ribosome-targeting antibiotic gentamicin. In summary, we identified the DNA gyrase as a target, but at low concentrations, electron microscopy and omics data revealed a more complex mode of action of cervimycin, which comprised induction of the heat shock response, indicating protein stress in the cell.IMPORTANCEAntibiotic resistance of Gram-positive bacteria is an emerging problem in modern medicine, and new antibiotics with novel modes of action are urgently needed. Secondary metabolites from Streptomyces species are an important source of antibiotics, like the cervimycin complex produced by Streptomyces tendae HKI 0179. The phenotypic response of Bacillus subtilis and Staphylococcus aureus toward cervimycin C indicated a chromosome segregation and septum formation defect. This effect was at first attributed to an interaction between cervimycin C and the DNA gyrase. However, omics data of cervimycin treated versus untreated S. aureus cells indicated a different mode of action, because the stress response did not include the SOS response but resembled the response toward antibiotics that induce mistranslation or premature chain termination and cause protein stress. In summary, these results point toward a possibly novel mechanism that generates protein stress in the cells and subsequently leads to defects in cell and chromosome segregation.
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Affiliation(s)
- Alina Hoffmann
- University Hospital Bonn, Institute of Medical Microbiology, Immunology and Parasitology, Bonn, Germany
| | - Ursula Steffens
- University Hospital Bonn, Institute of Medical Microbiology, Immunology and Parasitology, Bonn, Germany
| | - Boris Maček
- University of Tübingen, Proteome Center Tübingen, Tübingen, Germany
| | | | - Kay Nieselt
- University of Tübingen, Interfaculty Institute for Bioinformatics and Medical Informatics, Tübingen, Germany
| | - Theresa Anisja Harbig
- University of Tübingen, Interfaculty Institute for Bioinformatics and Medical Informatics, Tübingen, Germany
| | - Kirstin Scherlach
- Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Christian Hertweck
- Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
- Friedrich Schiller University Jena, Institute of Microbiology, Faculty of Biological Sciences, Jena, Germany
| | - Hans-Georg Sahl
- University of Bonn, Institute for Pharmaceutical Microbiology, Bonn, Germany
| | - Gabriele Bierbaum
- University Hospital Bonn, Institute of Medical Microbiology, Immunology and Parasitology, Bonn, Germany
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3
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Allemailem KS. Recent Advances in Understanding the Molecular Mechanisms of Multidrug Resistance and Novel Approaches of CRISPR/Cas9-Based Genome-Editing to Combat This Health Emergency. Int J Nanomedicine 2024; 19:1125-1143. [PMID: 38344439 PMCID: PMC10859101 DOI: 10.2147/ijn.s453566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 01/26/2024] [Indexed: 02/15/2024] Open
Abstract
The rapid spread of multidrug resistance (MDR), due to abusive use of antibiotics has led to global health emergency, causing substantial morbidity and mortality. Bacteria attain MDR by different means such as antibiotic modification/degradation, target protection/modification/bypass, and enhanced efflux mechanisms. The classical approaches of counteracting MDR bacteria are expensive and time-consuming, thus, it is highly significant to understand the molecular mechanisms of this resistance to curb the problem from core level. The revolutionary approach of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated sequence 9 (CRISPR/Cas9), considered as a next-generation genome-editing tool presents an innovative opportunity to precisely target and edit bacterial genome to alter their MDR strategy. Different bacteria possessing antibiotic resistance genes such as mecA, ermB, ramR, tetA, mqrB and blaKPC that have been targeted by CRISPR/Cas9 to re-sensitize these pathogens against antibiotics, such as methicillin, erythromycin, tigecycline, colistin and carbapenem, respectively. The CRISPR/Cas9 from S. pyogenes is the most widely studied genome-editing tool, consisting of a Cas9 DNA endonuclease associated with tracrRNA and crRNA, which can be systematically coupled as sgRNA. The targeting strategies of CRISPR/Cas9 to bacterial cells is mediated through phage, plasmids, vesicles and nanoparticles. However, the targeting approaches of this genome-editing tool to specific bacteria is a challenging task and still remains at a very preliminary stage due to numerous obstacles awaiting to be solved. This review elaborates some recent updates about the molecular mechanisms of antibiotic resistance and the innovative role of CRISPR/Cas9 system in modulating these resistance mechanisms. Furthermore, the delivery approaches of this genome-editing system in bacterial cells are discussed. In addition, some challenges and future prospects are also described.
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Affiliation(s)
- Khaled S Allemailem
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah51452, Saudi Arabia
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4
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Campbell AE, McCready-Vangi AR, Uberoi A, Murga-Garrido SM, Lovins VM, White EK, Pan JTC, Knight SAB, Morgenstern AR, Bianco C, Planet PJ, Gardner SE, Grice EA. Variable staphyloxanthin production by Staphylococcus aureus drives strain-dependent effects on diabetic wound-healing outcomes. Cell Rep 2023; 42:113281. [PMID: 37858460 PMCID: PMC10680119 DOI: 10.1016/j.celrep.2023.113281] [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: 10/21/2022] [Revised: 08/24/2023] [Accepted: 09/28/2023] [Indexed: 10/21/2023] Open
Abstract
Strain-level variation in Staphylococcus aureus is a factor that contributes to disease burden and clinical outcomes in skin disorders and chronic wounds. However, the microbial mechanisms that drive these variable host responses are poorly understood. To identify mechanisms underlying strain-specific outcomes, we perform high-throughput phenotyping screens on S. aureus isolates cultured from diabetic foot ulcers. Isolates from non-healing wounds produce more staphyloxanthin, a cell membrane pigment. In murine diabetic wounds, staphyloxanthin-producing isolates delay wound closure significantly compared with staphyloxanthin-deficient isolates. Staphyloxanthin promotes resistance to oxidative stress and enhances bacterial survival in neutrophils. Comparative genomic and transcriptomic analysis of genetically similar clinical isolates with disparate staphyloxanthin phenotypes reveals a mutation in the sigma B operon, resulting in marked differences in stress response gene expression. Our work illustrates a framework to identify traits that underlie strain-level variation in disease burden and suggests more precise targets for therapeutic intervention in S. aureus-positive wounds.
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Affiliation(s)
- Amy E Campbell
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amelia R McCready-Vangi
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aayushi Uberoi
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sofía M Murga-Garrido
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Victoria M Lovins
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ellen K White
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jamie Ting-Chun Pan
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Simon A B Knight
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexis R Morgenstern
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Colleen Bianco
- Division of Infectious Disease, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Paul J Planet
- Division of Infectious Disease, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Departments of Pediatrics and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sue E Gardner
- College of Nursing, University of Iowa, Iowa City, IA 52242, USA
| | - Elizabeth A Grice
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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5
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Jia J, Zheng M, Zhang C, Li B, Lu C, Bai Y, Tong Q, Hang X, Ge Y, Zeng L, Zhao M, Song F, Zhang H, Zhang L, Hong K, Bi H. Killing of Staphylococcus aureus persisters by a multitarget natural product chrysomycin A. SCIENCE ADVANCES 2023; 9:eadg5995. [PMID: 37540745 PMCID: PMC10403215 DOI: 10.1126/sciadv.adg5995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 07/05/2023] [Indexed: 08/06/2023]
Abstract
Staphylococcus aureus poses a severe public health problem as one of the vital causative agents of healthcare- and community-acquired infections. There is a globally urgent need for new drugs with a novel mode of action (MoA) to combat S. aureus biofilms and persisters that tolerate antibiotic treatment. We demonstrate that a benzonaphthopyranone glycoside, chrysomycin A (ChryA), is a rapid bactericide that is highly active against S. aureus persisters, robustly eradicates biofilms in vitro, and shows a sustainable killing efficacy in vivo. ChryA was suggested to target multiple critical cellular processes. A wide range of genetic and biochemical approaches showed that ChryA directly binds to GlmU and DapD, involved in the biosynthetic pathways for the cell wall peptidoglycan and lysine precursors, respectively, and inhibits the acetyltransferase activities by competition with their mutual substrate acetyl-CoA. Our study provides an effective antimicrobial strategy combining multiple MoAs onto a single small molecule for treatments of S. aureus persistent infections.
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Affiliation(s)
- Jia Jia
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Mingxin Zheng
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Chongwen Zhang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Binglei Li
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Cai Lu
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Yuefan Bai
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Qian Tong
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Xudong Hang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Yixin Ge
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Liping Zeng
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
| | - Ming Zhao
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Fuhang Song
- School of Light Industry, Beijing Technology and Business University, Beijing 100048, China
| | - Huawei Zhang
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
| | - Liang Zhang
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Kui Hong
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China
| | - Hongkai Bi
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing 211166, China
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6
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Al Ali A, Alsulami J, Aubee JI, Idowu A, Tomlinson BR, Felton EA, Jackson JK, Kennedy SJ, Torres NJ, Shaw LN, Thompson KM. Staphylococcus aureus SigS Induces Expression of a Regulatory Protein Pair That Modulates Its mRNA Stability. J Bacteriol 2023; 205:e0039222. [PMID: 37255480 PMCID: PMC10294688 DOI: 10.1128/jb.00392-22] [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: 10/17/2022] [Accepted: 04/13/2023] [Indexed: 06/01/2023] Open
Abstract
SigS is the sole extracytoplasmic function sigma factor in Staphylococcus aureus and is necessary for virulence, immune evasion, and adaptation to toxic chemicals and environmental stressors. Despite the contribution of SigS to a myriad of critical phenotypes, the downstream effectors of SigS-dependent pathogenesis, immune evasion, and stress adaptation remain elusive. To address this knowledge gap, we analyzed the S. aureus transcriptome following transient overexpression of SigS. We identified a bicistronic transcript, upregulated 1,000-fold, containing two midsized genes, each containing single domains of unknown function (DUFs). We renamed these genes SigS-regulated orfA (sroA) and SigS-regulated orfB (sroB). We demonstrated that SigS regulation of the sroAB operon is direct by using in vitro transcription analysis. Using Northern blot analysis, we also demonstrated that SroA and SroB have opposing autoregulatory functions on the transcriptional architecture of the sigS locus, with SroA stimulating SigS mRNA levels and SroB stimulating s750 (SigS antisense) levels. We hypothesized that these opposing regulatory effects were due to a direct interaction. We subsequently demonstrated a direct interaction between SroA and SroB using an in vivo surrogate genetics approach via bacterial adenylate cyclase-based two-hybrid (BACTH) analysis. We demonstrated that the SroA effect on SigS is at the posttranscriptional level of mRNA stability, highlighting a mechanism likely used by S. aureus to tightly control SigS levels. Finally, we demonstrate that the sroAB locus promotes virulence in a murine pneumonia model of infection. IMPORTANCE SigS is necessary for S. aureus virulence, immune evasion, and adaptation to chemical and environmental stressors. These processes are critically important for the ability of S. aureus to cause disease. However, the SigS-dependent transcriptome has not been identified, hindering our ability to identify downstream effectors of SigS that contribute to these pathogenic and adaptive phenotypes. Here, we identify a regulatory protein pair that is a major direct target of SigS, known as SroA and SroB. SroA also acts to stimulate SigS expression at the posttranscriptional level of RNA turnover, providing insight into intrinsically low levels of SigS. The discovery of SroA and SroB increases our understanding of SigS and the S. aureus pathogenesis process.
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Affiliation(s)
- Amer Al Ali
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
| | - Jamilah Alsulami
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
| | - Joseph I. Aubee
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
| | - Ayotimofe Idowu
- Department of Biology, College of Arts and Sciences, Howard University, Washington, DC, USA
| | - Brooke R. Tomlinson
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Emily A. Felton
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Jessica K. Jackson
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Sarah J. Kennedy
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Nathanial J. Torres
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Karl M. Thompson
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
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7
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Wilkinson AJ, Ooi N, Finlayson J, Lee VE, Lyth D, Maskew KS, Newman R, Orr D, Ansell K, Birchall K, Canning P, Coombs P, Fusani L, McIver E, Pisco J, Ireland PM, Jenkins C, Norville IH, Southern SJ, Cowan R, Hall G, Kettleborough C, Savage VJ, Cooper IR. Evaluating the druggability of TrmD, a potential antibacterial target, through design and microbiological profiling of a series of potent TrmD inhibitors. Bioorg Med Chem Lett 2023; 90:129331. [PMID: 37187252 DOI: 10.1016/j.bmcl.2023.129331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/17/2023]
Abstract
The post-transcriptional modifier tRNA-(N1G37) methyltransferase (TrmD) has been proposed to be essential for growth in many Gram-negative and Gram-positive pathogens, however previously reported inhibitors show only weak antibacterial activity. In this work, optimisation of fragment hits resulted in compounds with low nanomolar TrmD inhibition incorporating features designed to enhance bacterial permeability and covering a range of physicochemical space. The resulting lack of significant antibacterial activity suggests that whilst TrmD is highly ligandable, its essentiality and druggability are called into question.
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Affiliation(s)
- Andrew J Wilkinson
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK.
| | - Nicola Ooi
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Jonathan Finlayson
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Victoria E Lee
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - David Lyth
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Kathryn S Maskew
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Rebecca Newman
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - David Orr
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Keith Ansell
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Kristian Birchall
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Peter Canning
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Peter Coombs
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Lucia Fusani
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Ed McIver
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - João Pisco
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Philip M Ireland
- CBR division, Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK
| | | | | | | | - Richard Cowan
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, LE1 7RH, UK
| | - Gareth Hall
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, LE1 7RH, UK
| | | | - Victoria J Savage
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Ian R Cooper
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
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8
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Norambuena J, Al-Tameemi H, Bovermann H, Kim J, Beavers WN, Skaar EP, Parker D, Boyd JM. Copper ions inhibit pentose phosphate pathway function in Staphylococcus aureus. PLoS Pathog 2023; 19:e1011393. [PMID: 37235600 PMCID: PMC10249872 DOI: 10.1371/journal.ppat.1011393] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 06/08/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
To gain a better insight of how Copper (Cu) ions toxify cells, metabolomic analyses were performed in S. aureus strains that lacks the described Cu ion detoxification systems (ΔcopBL ΔcopAZ; cop-). Exposure of the cop- strain to Cu(II) resulted in an increase in the concentrations of metabolites utilized to synthesize phosphoribosyl diphosphate (PRPP). PRPP is created using the enzyme phosphoribosylpyrophosphate synthetase (Prs) which catalyzes the interconversion of ATP and ribose 5-phosphate to PRPP and AMP. Supplementing growth medium with metabolites requiring PRPP for synthesis improved growth in the presence of Cu(II). A suppressor screen revealed that a strain with a lesion in the gene coding adenine phosphoribosyltransferase (apt) was more resistant to Cu. Apt catalyzes the conversion of adenine with PRPP to AMP. The apt mutant had an increased pool of adenine suggesting that the PRPP pool was being redirected. Over-production of apt, or alternate enzymes that utilize PRPP, increased sensitivity to Cu(II). Increasing or decreasing expression of prs resulted in decreased and increased sensitivity to growth in the presence of Cu(II), respectively. We demonstrate that Prs is inhibited by Cu ions in vivo and in vitro and that treatment of cells with Cu(II) results in decreased PRPP levels. Lastly, we establish that S. aureus that lacks the ability to remove Cu ions from the cytosol is defective in colonizing the airway in a murine model of acute pneumonia, as well as the skin. The data presented are consistent with a model wherein Cu ions inhibits pentose phosphate pathway function and are used by the immune system to prevent S. aureus infections.
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Affiliation(s)
- Javiera Norambuena
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Hassan Al-Tameemi
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Hannah Bovermann
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Jisun Kim
- Department of Pathology, Immunology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey, United States of America
| | - William N. Beavers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Dane Parker
- Department of Pathology, Immunology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey, United States of America
| | - Jeffrey M. Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, United States of America
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9
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Fragment-Based Lead Discovery Strategies in Antimicrobial Drug Discovery. Antibiotics (Basel) 2023; 12:antibiotics12020315. [PMID: 36830226 PMCID: PMC9951956 DOI: 10.3390/antibiotics12020315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Fragment-based lead discovery (FBLD) is a powerful application for developing ligands as modulators of disease targets. This approach strategy involves identification of interactions between low-molecular weight compounds (100-300 Da) and their putative targets, often with low affinity (KD ~0.1-1 mM) interactions. The focus of this screening methodology is to optimize and streamline identification of fragments with higher ligand efficiency (LE) than typical high-throughput screening. The focus of this review is on the last half decade of fragment-based drug discovery strategies that have been used for antimicrobial drug discovery.
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10
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Menghani SV, Sanchez-Rosario Y, Pok C, Liu R, Gao F, O’Brien H, Neubert MJ, Ochoa K, Durckel M, Hellinger RD, Hackett N, Wang W, Johnson MDL. Novel dithiocarbamate derivatives are effective copper-dependent antimicrobials against Streptococcal species. Front Microbiol 2023; 13:1099330. [PMID: 36741900 PMCID: PMC9894897 DOI: 10.3389/fmicb.2022.1099330] [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: 11/15/2022] [Accepted: 12/15/2022] [Indexed: 01/21/2023] Open
Abstract
Despite the availability of several vaccines against multiple disease-causing strains of Streptococcus pneumoniae, the rise of antimicrobial resistance and pneumococcal disease caused by strains not covered by the vaccine creates a need for developing novel antimicrobial strategies. N,N-dimethyldithiocarbamate (DMDC) was found to be a potent copper-dependent antimicrobial against several pathogens, including S. pneumoniae. Here, DMDCs efficacy against Streptococcal pathogens Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus anginosus was tested using bactericidal and inductively coupled plasma - optical emission spectrometry. After confirming DMDC as broad-spectrum streptococcal antimicrobial, DMDC was derivatized into five compounds. The derivatives' effectiveness as copper chelators using DsRed2 and as copper-dependent antimicrobials against S. pneumoniae TIGR4 and tested in bactericidal and animal models. Two compounds, sodium N-benzyl-N-methyldithiocarbamate and sodium N-allyl-N-methyldithiocarbamate (herein "Compound 3" and "Compound 4"), were effective against TIGR4 and further, D39 and ATCC® 6303™ _(a type 3 capsular strain). Both Compound 3 and 4 increased the pneumococcal internal concentrations of copper to the same previously reported levels as with DMDC and copper treatment. However, in an in vivo murine pneumonia model, Compound 3, but not Compound 4, was effective in significantly decreasing the bacterial burden in the blood and lungs of S. pneumoniae-infected mice. These derivatives also had detrimental effects on the other streptococcal species. Collectively, derivatizing DMDC holds promise as potent bactericidal antibiotics against relevant streptococcal pathogens.
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Affiliation(s)
- Sanjay V. Menghani
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
- Medical Scientist Training MD-PhD Program (MSTP), University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Yamil Sanchez-Rosario
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Chansorena Pok
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
- Department of Microbial Pathogens and Immunity, Rush University, Chicago, IL, United States
| | - Renshuai Liu
- Department of Pharmacology and Toxicology, R. Ken Coit College of Pharmacy, University of Arizona, Tucson, AZ, United States
| | - Feng Gao
- Department of Pharmacology and Toxicology, R. Ken Coit College of Pharmacy, University of Arizona, Tucson, AZ, United States
| | - Henrik O’Brien
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Miranda J. Neubert
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Klariza Ochoa
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Meredythe Durckel
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Riley D. Hellinger
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
- Medical Scientist Training MD-PhD Program (MSTP), University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Nadia Hackett
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
| | - Wei Wang
- Department of Pharmacology and Toxicology, R. Ken Coit College of Pharmacy, University of Arizona, Tucson, AZ, United States
| | - Michael D. L. Johnson
- Department of Immunobiology, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
- Valley Fever Center for Excellence, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
- BIO5 Institute, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
- Asthma and Airway Disease Research Center, University of Arizona College of Medicine - Tucson, Tucson, AZ, United States
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11
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Spoto M, Riera Puma JP, Fleming E, Guan C, Ondouah Nzutchi Y, Kim D, Oh J. Large-Scale CRISPRi and Transcriptomics of Staphylococcus epidermidis Identify Genetic Factors Implicated in Lifestyle Versatility. mBio 2022; 13:e0263222. [PMID: 36409086 PMCID: PMC9765180 DOI: 10.1128/mbio.02632-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 10/27/2022] [Indexed: 11/23/2022] Open
Abstract
Staphylococcus epidermidis is a ubiquitous human commensal skin bacterium that is also one of the most prevalent nosocomial pathogens. The genetic factors underlying this remarkable lifestyle plasticity are incompletely understood, mainly due to the difficulties of genetic manipulation, precluding high-throughput functional profiling of this species. To probe the versatility of S. epidermidis to survive across a diversity of environmental conditions, we developed a large-scale CRISPR interference (CRISPRi) screen complemented by transcriptional profiling (RNA sequencing) across 24 diverse conditions and piloted a droplet-based CRISPRi approach to enhance throughput and sensitivity. We identified putative essential genes, importantly revealing amino acid metabolism as crucial to survival across diverse environments, and demonstrated the importance of trace metal uptake for survival under multiple stress conditions. We identified pathways significantly enriched and repressed across our range of stress and nutrient-limited conditions, demonstrating the considerable plasticity of S. epidermidis in responding to environmental stressors. Additionally, we postulate a mechanism by which nitrogen metabolism is linked to lifestyle versatility in response to hyperosmotic challenges, such as those encountered on human skin. Finally, we examined the survival of S. epidermidis under acid stress and hypothesize a role for cell wall modification as a vital component of the survival response under acidic conditions. Taken together, this study integrates large-scale CRISPRi and transcriptomics data across multiple environments to provide insights into a keystone member of the human skin microbiome. Our results additionally provide a valuable benchmarking analysis for CRISPRi screens and are a rich resource for other staphylococcal researchers. IMPORTANCE Staphylococcus epidermidis is a bacteria that broadly inhabits healthy human skin, yet it is also a common cause of skin infections and bloodstream infections associated with implanted medical devices. Because human skin has many different types of S. epidermidis, each containing different genes, our goal is to determine how these different genes allow S. epidermidis to switch from healthy growth in the skin to being an infectious pathogen. Understanding this switch is critical to developing new strategies to prevent and treat S. epidermidis infections.
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Affiliation(s)
- Michelle Spoto
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
- The University of Connecticut Health Center, Farmington, Connecticut, USA
| | | | - Elizabeth Fleming
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | - Changhui Guan
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | | | - Dean Kim
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | - Julia Oh
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
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12
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Kundar R, Gokarn K. CRISPR-Cas System: A Tool to Eliminate Drug-Resistant Gram-Negative Bacteria. Pharmaceuticals (Basel) 2022; 15:ph15121498. [PMID: 36558949 PMCID: PMC9781512 DOI: 10.3390/ph15121498] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/18/2022] [Accepted: 11/24/2022] [Indexed: 12/04/2022] Open
Abstract
Rapidly emerging drug-resistant superbugs, especially Gram-negative bacteria, pose a serious threat to healthcare systems all over the globe. Newer strategies are being developed to detect and overcome the arsenal of weapons that these bacteria possess. The development of antibiotics is time-consuming and may not provide full proof of action on evolving drug-resistant pathogens. The clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas) systems are promising in curbing drug-resistant bacteria. This review focuses on the pathogenesis of Gram-negative bacteria, emergence of antimicrobial drug resistance, and their treatment failures. It also draws attention to the present status of the CRISPR-Cas system in diagnosisand treatment of Gram-negative bacterial infections.
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Affiliation(s)
- Rajeshwari Kundar
- Department of Microbiology, Sir H.N. Medical Research Society, Sir H.N. Reliance Foundation Hospital & Research Centre, Mumbai 400004, Maharashtra, India
| | - Karuna Gokarn
- Department of Microbiology, Sir H.N. Medical Research Society, Sir H.N. Reliance Foundation Hospital & Research Centre, Mumbai 400004, Maharashtra, India
- Department of Microbiology, St. Xavier’s College, 5- Mahapalika Marg, Mumbai 400001, Maharashtra, India
- Correspondence: or
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13
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Banerjee A, Mukherjee D, Bera A, Ghosh R, Mondal S, Mukhopadhyay S, Das R, Altass HM, Natto SSA, Moussa Z, Ahmed SA, Chattopadhyay A, Pal SK. Molecular co-localization of multiple drugs in a nanoscopic delivery vehicle for potential synergistic remediation of multi-drug resistant bacteria. Sci Rep 2022; 12:18881. [PMID: 36344591 PMCID: PMC9640573 DOI: 10.1038/s41598-022-22759-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 10/19/2022] [Indexed: 11/09/2022] Open
Abstract
Anti-microbial resistant infection is predicted to be alarming in upcoming years. In the present study, we proposed co-localization of two model drugs viz., rifampicin and benzothiazole used in anti-tuberculosis and anti-fungal agents respectively in a nanoscopic cationic micelle (cetyl triethyl ammonium bromide) with hydrodynamic diameter of 2.69 nm. Sterilization effect of the co-localized micellar formulation against a model multi-drug resistant bacterial strain viz., Methicillin resistant Staphylococcus aureus was also investigated. 99.88% decrease of bacterial growth in terms of colony forming unit was observed using the developed formulation. While Dynamic Light Scattering and Forsters Resonance Energy Transfer between benzothiazole and rifampicin show co-localization of the drugs in the nanoscopic micellar environment, analysis of time-resolved fluorescence decays by Infelta-Tachiya model and the probability distribution of the donor-acceptor distance fluctuations for 5 μM,10 μM and 15 μM acceptor concentrations confirm efficacy of the co-localization. Energy transfer efficiency and the donor acceptor distance are found to be 46% and 20.9 Å respectively. We have also used a detailed computational biology framework to rationalize the sterilization effect of our indigenous formulation. It has to be noted that the drugs used in our studies are not being used for their conventional indication. Rather the co-localization of the drugs in the micellar environment shows a completely different indication of their use in the remediation of multi-drug resistant bacteria revealing the re-purposing of the drugs for potential use in hospital-born multi-drug resistant bacterial infection.
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Affiliation(s)
- Amrita Banerjee
- Department of Physics, Jadavpur University, 188, Raja S.C. Mallick Rd, Kolkata, 700032, India
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, 700106, West Bengal, India
| | - Dipanjan Mukherjee
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Arpan Bera
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Ria Ghosh
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Susmita Mondal
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Subhadipta Mukhopadhyay
- Department of Physics, Jadavpur University, 188, Raja S.C. Mallick Rd, Kolkata, 700032, India
| | - Ranjan Das
- Department of Chemistry, West Bengal State University, Kolkata, 700106, India
| | - Hatem M Altass
- Chemistry Department, Faculty of Applied Science, Umm Al-Qura University, Mecca, 21955, Saudi Arabia
| | - Sameer S A Natto
- Physcis Department, Faculty of Applied Science, Umm Al-Qura University, Mecca, 21955, Saudi Arabia
| | - Ziad Moussa
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain, P.O. Box 15551, Abu Dhabi, United Arab Emirates
| | - Saleh A Ahmed
- Chemistry Department, Faculty of Applied Science, Umm Al-Qura University, Mecca, 21955, Saudi Arabia.
| | - Arpita Chattopadhyay
- Department of Basic Science and Humanities, Techno International New Town Block, DG 1/1, Action Area 1 New Town, Rajarhat, Kolkata, 700156, India.
- Department of Physics, Sister Nivedita University, DG 1/2 New Town, Action Area 1, Kolkata, 700156, India.
| | - Samir Kumar Pal
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India.
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14
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Cervimycin-Resistant Staphylococcus aureus Strains Display Vancomycin-Intermediate Resistant Phenotypes. Microbiol Spectr 2022; 10:e0256722. [PMID: 36173303 PMCID: PMC9603734 DOI: 10.1128/spectrum.02567-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Resistance to antibiotics is an increasing problem and necessitates novel antibacterial therapies. The polyketide antibiotics cervimycin A to D are natural products of Streptomyces tendae HKI 0179 with promising activity against multidrug-resistant staphylococci and vancomycin-resistant enterococci. To initiate mode of action studies, we selected cervimycin C- and D-resistant (CmR) Staphylococcus aureus strains. Genome sequencing of CmR mutants revealed amino acid exchanges in the essential histidine kinase WalK, the Clp protease proteolytic subunit ClpP or the Clp ATPase ClpC, and the heat shock protein DnaK. Interestingly, all characterized CmR mutants harbored a combination of mutations in walK and clpP or clpC. In vitro and in vivo analyses showed that the mutations in the Clp proteins abolished ClpP or ClpC activity, and the deletion of clpP rendered S. aureus but not all Bacillus subtilis strains cervimycin-resistant. The essential gene walK was the second mutational hotspot in the CmR S. aureus strains, which decreased WalK activity in vitro and generated a vancomycin-intermediate resistant phenotype, with a thickened cell wall, a lower growth rate, and reduced cell lysis. Transcriptomic and proteomic analyses revealed massive alterations in the CmR strains compared to the parent strain S. aureus SG511, with major shifts in the heat shock regulon, the metal ion homeostasis, and the carbohydrate metabolism. Taken together, mutations in the heat shock genes clpP, clpC, and dnaK, and the walK kinase gene in CmR mutants induced a vancomycin-intermediate resistant phenotype in S. aureus, suggesting cell wall metabolism or the Clp protease system as primary target of cervimycin. IMPORTANCE Staphylococcus aureus is a frequent cause of infections in both the community and hospital setting. Resistance development of S. aureus to various antibiotics is a severe problem for the treatment of this pathogen worldwide. New powerful antimicrobial agents against Gram-positives are needed, since antibiotics like vancomycin fail to cure vancomycin-intermediate resistant S. aureus (VISA) and vancomycin-resistant enterococci (VRE) infections. One candidate substance with promising activity against these organisms is cervimycin, which is an antibiotic complex with a yet unknown mode of action. In our study, we provide first insights into the mode of action of cervimycins. By characterizing cervimycin-resistant S. aureus strains, we revealed the Clp system and the essential kinase WalK as mutational hotspots for cervimycin resistance in S. aureus. It further emerged that cervimycin-resistant S. aureus strains show a VISA phenotype, indicating a role of cervimycin in perturbing the bacterial cell envelope.
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15
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Zhou J, Cai Y, Liu Y, An H, Deng K, Ashraf MA, Zou L, Wang J. Breaking down the cell wall: Still an attractive antibacterial strategy. Front Microbiol 2022; 13:952633. [PMID: 36212892 PMCID: PMC9544107 DOI: 10.3389/fmicb.2022.952633] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.
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Affiliation(s)
- Jingxuan Zhou
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Yi Cai
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Ying Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Haoyue An
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Kaihong Deng
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Muhammad Awais Ashraf
- Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Lili Zou
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Jun Wang
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- *Correspondence: Jun Wang,
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16
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Turgimbayeva A, Zein U, Zharkov DO, Ramankulov Y, Saparbaev M, Abeldenov S. Cloning and characterization of the major AP endonuclease from Staphylococcus aureus. DNA Repair (Amst) 2022; 119:103390. [DOI: 10.1016/j.dnarep.2022.103390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/19/2022] [Accepted: 08/20/2022] [Indexed: 11/03/2022]
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17
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Hogan AM, Cardona ST. Gradients in gene essentiality reshape antibacterial research. FEMS Microbiol Rev 2022; 46:fuac005. [PMID: 35104846 PMCID: PMC9075587 DOI: 10.1093/femsre/fuac005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 02/03/2023] Open
Abstract
Essential genes encode the processes that are necessary for life. Until recently, commonly applied binary classifications left no space between essential and non-essential genes. In this review, we frame bacterial gene essentiality in the context of genetic networks. We explore how the quantitative properties of gene essentiality are influenced by the nature of the encoded process, environmental conditions and genetic background, including a strain's distinct evolutionary history. The covered topics have important consequences for antibacterials, which inhibit essential processes. We argue that the quantitative properties of essentiality can thus be used to prioritize antibacterial cellular targets and desired spectrum of activity in specific infection settings. We summarize our points with a case study on the core essential genome of the cystic fibrosis pathobiome and highlight avenues for targeted antibacterial development.
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Affiliation(s)
- Andrew M Hogan
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Room 543 - 745 Bannatyne Avenue, Winnipeg, Manitoba, R3E 0J9, Canada
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18
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Sharma S, Rao R, Reeve SM, Phelps GA, Bharatham N, Katagihallimath N, Ramachandran V, Raveendran S, Sarma M, Nath A, Thomas T, Manickam D, Nagaraj S, Balasubramanian V, Lee RE, Hameed P S, Datta S. Azaindole Based Potentiator of Antibiotics against Gram-Negative Bacteria. ACS Infect Dis 2021; 7:3009-3024. [PMID: 34699190 DOI: 10.1021/acsinfecdis.1c00171] [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] [Indexed: 11/28/2022]
Abstract
We discovered azaindole-based compounds with weak innate activity that exhibit substantial potentiation of antibacterial activities of different antibiotics, viz., rifampicin, erythromycin, solithromycin, and novobiocin in Gram-negative bacteria. In the presence of the azaindole derivatives, these antibiotics exhibited submicromolar minimum inhibitory concentrations (MICs) against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The fold improvements in MIC of these antibiotics that were otherwise weak or inactive on their own against these bacteria were also observed against drug-resistant clinical isolates. Our studies indicate that this selective potentiation is probably through destabilization of the outer membrane's integrity, known to be regulated by the lipopolysaccharides (LPS). Thus, the azaindole based compounds described here open opportunities for those antibiotics that are otherwise ineffective due to LPS mediated entry barriers in Gram-negative bacteria.
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Affiliation(s)
- Sreevalli Sharma
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
- The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bengaluru, Karnataka-560064, India
| | - Ranga Rao
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
- The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bengaluru, Karnataka-560064, India
| | - Stephanie M. Reeve
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
| | - Gregory A. Phelps
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
- Graduate School of Biomedical Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
| | - Nagakumar Bharatham
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
- The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bengaluru, Karnataka-560064, India
| | - Nainesh Katagihallimath
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
- The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bengaluru, Karnataka-560064, India
| | - Vasanthi Ramachandran
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
- The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bengaluru, Karnataka-560064, India
| | - Savitha Raveendran
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
| | - Maitrayee Sarma
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
| | - Anubha Nath
- St. John’s Research Institute, Bengaluru, Karnataka-560034, India
| | - Teby Thomas
- St. John’s Research Institute, Bengaluru, Karnataka-560034, India
| | - Dhanasekaran Manickam
- Syngene International Ltd., Plot 2 & 3, Bommasandra Industrial Estate - Phase-IV, Bommasandra-Jigani Link Road, Bengaluru, Karnataka 560099, India
| | - Savitha Nagaraj
- St. John’s Medical Hospital, Bengaluru, Karnataka-560034, India
| | - V. Balasubramanian
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
| | - Richard E. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
| | - Shahul Hameed P
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
- The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bengaluru, Karnataka-560064, India
| | - Santanu Datta
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, GKVK, Bellary Rd, Bangalore, Karnataka 560065, India
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19
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Bekaert M, Goffin N, McMillan S, Desbois AP. Essential Genes of Vibrio anguillarum and Other Vibrio spp. Guide the Development of New Drugs and Vaccines. Front Microbiol 2021; 12:755801. [PMID: 34745063 PMCID: PMC8564382 DOI: 10.3389/fmicb.2021.755801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/24/2021] [Indexed: 01/04/2023] Open
Abstract
Essential genes in bacterial pathogens are potential drug targets and vaccine candidates because disrupting their function is lethal. The development of new antibiotics, in addition to effective prevention measures such as vaccination, contributes to addressing the global problem of bacterial antibiotic resistance. The aim of this present study was to determine the essential genes of Vibrio anguillarum, a bacterial pathogen of aquatic animals, as a means to identify putative targets for novel drugs and to assist the prioritisation of potential vaccine candidates. Essential genes were characterised by a Tn-seq approach using the TnSC189 mariner transposon to construct a library of 52,662 insertion mutants. In total, 329 essential genes were identified, with 34.7% found within the core genome of this species; each of these genes represents a strong potential drug target. Seven essential gene products were predicted to reside in the cell membrane or be released extracellularly, thus serving as putative vaccine candidates. Comparison to essential gene data from five other studies of Vibrio species revealed 13 proteins to be conserved across the studies, while 25 genes were specific to V. anguillarum and not found to be essential in the other Vibrio spp. This study provides new information on the essential genes of Vibrio species and the methodology may be applied to other pathogens to guide the development of new drugs and vaccines, which will assist efforts to counter antibiotic resistance.
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Affiliation(s)
- Michaël Bekaert
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Nikki Goffin
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Stuart McMillan
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Andrew P Desbois
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
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20
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Union is strength: target-based and whole-cell high throughput screens in antibacterial discovery. J Bacteriol 2021; 204:e0047721. [PMID: 34723646 DOI: 10.1128/jb.00477-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial resistance is one of the greatest global health challenges today. For over three decades antibacterial discovery research and development has been focused on cell-based and target-based high throughput assays. Target-based screens use diagnostic enzymatic reactions to look for molecules that can bind directly and inhibit the target. Target-based screens are only applied to proteins that can be successfully expressed, purified and the activity of which can be effectively measured using a biochemical assay. Often times the molecules found in these in vitro screens are not active in cells due to poor permeability or efflux. On the other hand, cell-based screens use whole cells and look for growth inhibition. These screens give higher number of hits than target-based assays and can simultaneously test many targets of one process or pathway in their physiological context. Both strategies have pros and cons when used separately. In the past decade and a half our increasing knowledge of bacterial physiology has led to the development of innovative and sophisticated technologies to perform high throughput screening combining these two strategies and thus minimizing their disadvantages. In this review we discuss recent examples of high throughput approaches that used both target-based and whole-cell screening to find new antibacterials, the new insights they have provided and how this knowledge can be applied to other in vivo validated targets to develop new antimicrobials.
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21
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Cheung AL, Cho J, Bayer AS, Yeaman MR, Xiong YQ, Donegan NP, Mikheyeva IV, Lee GY, Yang SJ. Role of the Staphylococcus aureus Extracellular Loop of GraS in Resistance to Distinct Human Defense Peptides in PMN and Invasive Cardiovascular infections. Infect Immun 2021; 89:e0034721. [PMID: 34227840 PMCID: PMC8445198 DOI: 10.1128/iai.00347-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 11/20/2022] Open
Abstract
GraS is a membrane sensor in Staphylococcus aureus that induces mprF and dltABCD expression to alter the surface positive charge upon exposure to cationic human defense peptides (HDPs). The sensing domain of GraS likely resides in the 9-residue extracellular loop (EL). In this study, we assessed a hospital-acquired methicillin-resistant S. aureus (HA-MRSA) strain (COL) for the specific role of two distinct EL mutations: F38G (bulk) and D/35/37/41K (charged inversion). Activation of mprF by polymyxin B (PMB) was reduced in the D35/37/41K mutant versus the D35/37/41G mutant, correlating with reduced surface positive charge; in contrast, these effects were less prominent in the F38G mutant but still lower than those in the parent. These data indicated that both electrostatic charge and steric bulk of the EL of GraS influence induction of genes impacting HDP resistance. Using mprF expression as a readout, we confirmed GraS signaling was pH dependent, increasing as pH was lowered (from pH 7.5 down to pH 5.5). In contrast to PMB activation, reduction of mprF was comparable at pH 5.5 between the P38G and D35/37/41K point mutants, indicating a mechanistic divergence between GraS activation by acidic pH versus cationic peptides. Survival assays in human blood and purified polymorphonuclear leukocytes (PMNs) revealed lower survival of the D35/37/41K mutant versus the F38G mutant, with both being lower than that of the parent. Virulence studies in the rabbit endocarditis model mirrored whole blood and PMN killing assay data described above. Collectively, these data confirmed the importance of specific residues within the EL of GraS in conferring essential bacterial responses for MRSA survival in infections.
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Affiliation(s)
- Ambrose L. Cheung
- Department of Microbiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Junho Cho
- Department of Microbiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Arnold S. Bayer
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
- Department of Medicine, Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA
- The David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Michael R. Yeaman
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
- Department of Medicine, Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA
- The David Geffen School of Medicine at UCLA, Los Angeles, California, USA
- Department of Medicine, Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
| | - Yan Q. Xiong
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
- Department of Medicine, Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA
- The David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Niles P. Donegan
- Department of Microbiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Irina V. Mikheyeva
- Department of Microbiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Gi Yong Lee
- Department of Veterinary Microbiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
| | - Soo-Jin Yang
- Department of Veterinary Microbiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
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22
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Patel JS, Norambuena J, Al-Tameemi H, Ahn YM, Perryman AL, Wang X, Daher SS, Occi J, Russo R, Park S, Zimmerman M, Ho HP, Perlin DS, Dartois V, Ekins S, Kumar P, Connell N, Boyd JM, Freundlich JS. Bayesian Modeling and Intrabacterial Drug Metabolism Applied to Drug-Resistant Staphylococcus aureus. ACS Infect Dis 2021; 7:2508-2521. [PMID: 34342426 DOI: 10.1021/acsinfecdis.1c00265] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We present the application of Bayesian modeling to identify chemical tools and/or drug discovery entities pertinent to drug-resistant Staphylococcus aureus infections. The quinoline JSF-3151 was predicted by modeling and then empirically demonstrated to be active against in vitro cultured clinical methicillin- and vancomycin-resistant strains while also exhibiting efficacy in a mouse peritonitis model of methicillin-resistant S. aureus infection. We highlight the utility of an intrabacterial drug metabolism (IBDM) approach to probe the mechanism by which JSF-3151 is transformed within the bacteria. We also identify and then validate two mechanisms of resistance in S. aureus: one mechanism involves increased expression of a lipocalin protein, and the other arises from the loss of function of an azoreductase. The computational and experimental approaches, discovery of an antibacterial agent, and elucidated resistance mechanisms collectively hold promise to advance our understanding of therapeutic regimens for drug-resistant S. aureus.
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Affiliation(s)
- Jimmy S. Patel
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Javiera Norambuena
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, United States
| | - Hassan Al-Tameemi
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, United States
| | - Yong-Mo Ahn
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Alexander L. Perryman
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Xin Wang
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - Samer S. Daher
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
| | - James Occi
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Riccardo Russo
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Steven Park
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Matthew Zimmerman
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Hsin-Pin Ho
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - David S. Perlin
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Véronique Dartois
- Public Health Research Institute, Rutgers University − New Jersey Medical School, 225 Warren St, Newark, New Jersey 07103, United States
| | - Sean Ekins
- Collaborations in Chemistry, 5616 Hilltop Needmore Road, Fuquay-Varina, North Carolina 27526, United States
| | - Pradeep Kumar
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Nancy Connell
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Jeffrey M. Boyd
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, United States
| | - Joel S. Freundlich
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers University − New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States
- Department of Medicine, Center for Emerging and Re-emerging Pathogens, Rutgers University − New Jersey Medical School, Newark, New Jersey 07103, United States
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23
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Costa SK, Cho J, Cheung AL. GraS Sensory Activity in Staphylococcus epidermidis Is Modulated by the "Guard Loop" of VraG and the ATPase Activity of VraF. J Bacteriol 2021; 203:e0017821. [PMID: 34096781 PMCID: PMC8351631 DOI: 10.1128/jb.00178-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/01/2021] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial peptides (AMPs) are one of the key immune responses that can eliminate pathogenic bacteria through membrane perturbation. As a successful skin commensal, Staphylococcus epidermidis can sense and respond to AMPs through the GraXRS two-component system and an efflux system comprising the VraG permease and VraF ATPase. GraS is a membrane sensor known to function in AMP resistance through a negatively charged, 9-residue extracellular loop, which is predicted to be linear without any secondary structure. An important question is how GraS can impart effective sensing of AMPs through such a small unstructured sequence. In this study, we verified the role of graS and vraG in AMP sensing in S. epidermidis, as demonstrated by the failure of the ΔgraS or ΔvraG mutants to sense. Deletion of the extracellular loop of VraG did not affect sensing but reduced survival with polymyxin B. Importantly, a specific region within the extracellular loop, termed the guard loop (GL), has inhibitory activity since sensing of polymyxin B was enhanced in the ΔGL mutant, indicating that the GL may act as a gatekeeper for sensing. Bacterial two-hybrid analysis demonstrated that the extracellular regions of GraS and VraG interact, but interaction appears dispensable to sensing activity. Mutation of the extracellular loop of VraG, the GL, and the active site of VraF suggested that an active detoxification function of VraG is necessary for AMP resistance. Altogether, we provide evidence for a unique sensory scheme that relies on the function of a permease to impart effective information processing. IMPORTANCE Staphylococcus epidermidis has become an important opportunistic pathogen that is responsible for nosocomial and device-related infections that account for considerable morbidity worldwide. A thorough understanding of the mechanisms that enable S. epidermidis to colonize human skin successfully is essential for the development of alternative treatment strategies and prophylaxis. Here, we demonstrate the importance of an AMP response system in a clinically relevant S. epidermidis strain. Furthermore, we provide evidence for a unique sensory scheme that would rely on the detoxification function of a permease to effect information processing.
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Affiliation(s)
- Stephen K. Costa
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Junho Cho
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Ambrose L. Cheung
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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24
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Hibernation-Promoting Factor Sequesters Staphylococcus aureus Ribosomes to Antagonize RNase R-Mediated Nucleolytic Degradation. mBio 2021; 12:e0033421. [PMID: 34253058 PMCID: PMC8406268 DOI: 10.1128/mbio.00334-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Bacterial and eukaryotic hibernation factors prevent translation by physically blocking the decoding center of ribosomes, a phenomenon called ribosome hibernation that often occurs in response to nutrient deprivation. The human pathogen Staphylococcus aureus lacking the sole hibernation factor HPF undergoes massive ribosome degradation via an unknown pathway. Using genetic and biochemical approaches, we find that inactivating the 3′-to-5′ exonuclease RNase R suppresses ribosome degradation in the Δhpf mutant. In vitro cell-free degradation assays confirm that 30S and 70S ribosomes isolated from the Δhpf mutant are extremely susceptible to RNase R, in stark contrast to nucleolytic resistance of the HPF-bound 70S and 100S complexes isolated from the wild type. In the absence of HPF, specific S. aureus 16S rRNA helices are sensitive to nucleolytic cleavage. These RNase hot spots are distinct from that found in the Escherichia coli ribosomes. S. aureus RNase R is associated with ribosomes, but unlike the E. coli counterpart, it is not regulated by general stressors and acetylation. The results not only highlight key differences between the evolutionarily conserved RNase R homologs but also provide direct evidence that HPF preserves ribosome integrity beyond its role in translational avoidance, thereby poising the hibernating ribosomes for rapid resumption of translation.
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25
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Serral F, Castello FA, Sosa EJ, Pardo AM, Palumbo MC, Modenutti C, Palomino MM, Lazarowski A, Auzmendi J, Ramos PIP, Nicolás MF, Turjanski AG, Martí MA, Fernández Do Porto D. From Genome to Drugs: New Approaches in Antimicrobial Discovery. Front Pharmacol 2021; 12:647060. [PMID: 34177572 PMCID: PMC8219968 DOI: 10.3389/fphar.2021.647060] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 05/17/2021] [Indexed: 01/31/2023] Open
Abstract
Decades of successful use of antibiotics is currently challenged by the emergence of increasingly resistant bacterial strains. Novel drugs are urgently required but, in a scenario where private investment in the development of new antimicrobials is declining, efforts to combat drug-resistant infections become a worldwide public health problem. Reasons behind unsuccessful new antimicrobial development projects range from inadequate selection of the molecular targets to a lack of innovation. In this context, increasingly available omics data for multiple pathogens has created new drug discovery and development opportunities to fight infectious diseases. Identification of an appropriate molecular target is currently accepted as a critical step of the drug discovery process. Here, we review how diverse layers of multi-omics data in conjunction with structural/functional analysis and systems biology can be used to prioritize the best candidate proteins. Once the target is selected, virtual screening can be used as a robust methodology to explore molecular scaffolds that could act as inhibitors, guiding the development of new drug lead compounds. This review focuses on how the advent of omics and the development and application of bioinformatics strategies conduct a "big-data era" that improves target selection and lead compound identification in a cost-effective and shortened timeline.
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Affiliation(s)
- Federico Serral
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Florencia A Castello
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ezequiel J Sosa
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Buenos Aires, Argentina
| | - Agustín M Pardo
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Buenos Aires, Argentina
| | - Miranda Clara Palumbo
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Carlos Modenutti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Buenos Aires, Argentina
| | - María Mercedes Palomino
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Buenos Aires, Argentina
| | - Alberto Lazarowski
- Departamento de Bioquímica Clínica, Instituto de Investigaciones en Fisiopatología y Bioquímica Clínica (INFIBIOC), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jerónimo Auzmendi
- Departamento de Bioquímica Clínica, Instituto de Investigaciones en Fisiopatología y Bioquímica Clínica (INFIBIOC), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Pablo Ivan P Ramos
- Centro de Integração de Dados e Conhecimentos para Saúde (CIDACS), Instituto Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Brazil
| | - Marisa F Nicolás
- Laboratório Nacional de Computação Científica (LNCC), Petrópolis, Brazil
| | - Adrián G Turjanski
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marcelo A Martí
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Buenos Aires, Argentina
| | - Darío Fernández Do Porto
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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26
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da Cunha BR, Zoio P, Fonseca LP, Calado CRC. Technologies for High-Throughput Identification of Antibiotic Mechanism of Action. Antibiotics (Basel) 2021; 10:565. [PMID: 34065815 PMCID: PMC8151116 DOI: 10.3390/antibiotics10050565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/05/2021] [Accepted: 05/10/2021] [Indexed: 01/23/2023] Open
Abstract
There are two main strategies for antibiotic discovery: target-based and phenotypic screening. The latter has been much more successful in delivering first-in-class antibiotics, despite the major bottleneck of delayed Mechanism-of-Action (MOA) identification. Although finding new antimicrobial compounds is a very challenging task, identifying their MOA has proven equally challenging. MOA identification is important because it is a great facilitator of lead optimization and improves the chances of commercialization. Moreover, the ability to rapidly detect MOA could enable a shift from an activity-based discovery paradigm towards a mechanism-based approach. This would allow to probe the grey chemical matter, an underexplored source of structural novelty. In this study we review techniques with throughput suitable to screen large libraries and sufficient sensitivity to distinguish MOA. In particular, the techniques used in chemical genetics (e.g., based on overexpression and knockout/knockdown collections), promoter-reporter libraries, transcriptomics (e.g., using microarrays and RNA sequencing), proteomics (e.g., either gel-based or gel-free techniques), metabolomics (e.g., resourcing to nuclear magnetic resonance or mass spectrometry techniques), bacterial cytological profiling, and vibrational spectroscopy (e.g., Fourier-transform infrared or Raman scattering spectroscopy) were discussed. Ultimately, new and reinvigorated phenotypic assays bring renewed hope in the discovery of a new generation of antibiotics.
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Affiliation(s)
- Bernardo Ribeiro da Cunha
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico (IST), Universidade de Lisboa (UL), Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (B.R.d.C.); (P.Z.); (L.P.F.)
| | - Paulo Zoio
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico (IST), Universidade de Lisboa (UL), Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (B.R.d.C.); (P.Z.); (L.P.F.)
- CIMOSM—Centro de Investigação em Modelação e Optimização de Sistemas Multifuncionais, ISEL—Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro 1, 1959-007 Lisboa, Portugal
| | - Luís P. Fonseca
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico (IST), Universidade de Lisboa (UL), Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (B.R.d.C.); (P.Z.); (L.P.F.)
| | - Cecília R. C. Calado
- CIMOSM—Centro de Investigação em Modelação e Optimização de Sistemas Multifuncionais, ISEL—Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro 1, 1959-007 Lisboa, Portugal
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27
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Abstract
Ribosomal proteins (RPs) are highly conserved across the bacterial and archaeal domains. Although many RPs are essential for survival, genome analysis demonstrates the absence of some RP genes in many bacterial and archaeal genomes. Furthermore, global transposon mutagenesis and/or targeted deletion showed that elimination of some RP genes had only a moderate effect on the bacterial growth rate. Here, we systematically analyze the evolutionary conservation of RPs in prokaryotes by compiling the list of the ribosomal genes that are missing from one or more genomes in the recently updated version of the Clusters of Orthologous Genes (COG) database. Some of these absences occurred because the respective genes carried frameshifts, presumably, resulting from sequencing errors, while others were overlooked and not translated during genome annotation. Apart from these annotation errors, we identified multiple genuine losses of RP genes in a variety of bacteria and archaea. Some of these losses are clade-specific, whereas others occur in symbionts and parasites with dramatically reduced genomes. The lists of computationally and experimentally defined non-essential ribosomal genes show a substantial overlap, revealing a common trend in prokaryote ribosome evolution that could be linked to the architecture and assembly of the ribosomes. Thus, RPs that are located at the surface of the ribosome and/or are incorporated at a late stage of ribosome assembly are more likely to be non-essential and to be lost during microbial evolution, particularly, in the course of genome compaction.IMPORTANCEIn many prokaryote genomes, one or more ribosomal protein (RP) genes are missing. Analysis of 1,309 prokaryote genomes included in the COG database shows that only about half of the RPs are universally conserved in bacteria and archaea. In contrast, up to 16 other RPs are missing in some genomes, primarily, tiny (<1 Mb) genomes of host-associated bacteria and archaea. Ten universal and nine archaea-specific ribosomal proteins show clear patterns of lineage-specific gene loss. Most of the RPs that are frequently lost from bacterial genomes are located on the ribosome periphery and are non-essential in Escherichia coli and Bacillus subtilis These results reveal general trends and common constraints in the architecture and evolution of ribosomes in prokaryotes.
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28
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Liu T, Luo H, Gao F. Position preference of essential genes in prokaryotic operons. PLoS One 2021; 16:e0250380. [PMID: 33886641 PMCID: PMC8061932 DOI: 10.1371/journal.pone.0250380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 04/05/2021] [Indexed: 11/19/2022] Open
Abstract
Essential genes, which form the basis of life activities, are crucial for the survival of organisms. Essential genes tend to be located in operons, but how they are distributed in operons is still unclear for most prokaryotes. In order to clarify the general rule of position preference of essential genes in operons, an index of the average position of genes in an operon was proposed, and the distributions of essential and non-essential genes in operons in 51 bacterial genomes and two archaeal genomes were analyzed based on this new index. Consequently, essential genes were found to preferentially occupy the front positions of the operons, which tend to be expressed at higher levels.
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Affiliation(s)
- Tao Liu
- Department of Physics, School of Science, Tianjin University, Tianjin, China
| | - Hao Luo
- Department of Physics, School of Science, Tianjin University, Tianjin, China
- * E-mail: (FG); (HL)
| | - Feng Gao
- Department of Physics, School of Science, Tianjin University, Tianjin, China
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
- * E-mail: (FG); (HL)
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29
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Zondervan NA, Martins Dos Santos VAP, Suarez-Diez M, Saccenti E. Phenotype and multi-omics comparison of Staphylococcus and Streptococcus uncovers pathogenic traits and predicts zoonotic potential. BMC Genomics 2021; 22:102. [PMID: 33541265 PMCID: PMC7860044 DOI: 10.1186/s12864-021-07388-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 01/13/2021] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Staphylococcus and Streptococcus species can cause many different diseases, ranging from mild skin infections to life-threatening necrotizing fasciitis. Both genera consist of commensal species that colonize the skin and nose of humans and animals, and of which some can display a pathogenic phenotype. RESULTS We compared 235 Staphylococcus and 315 Streptococcus genomes based on their protein domain content. We show the relationships between protein persistence and essentiality by integrating essentiality predictions from two metabolic models and essentiality measurements from six large-scale transposon mutagenesis experiments. We identified clusters of strains within species based on proteins associated to similar biological processes. We built Random Forest classifiers that predicted the zoonotic potential. Furthermore, we identified shared attributes between of Staphylococcus aureus and Streptococcus pyogenes that allow them to cause necrotizing fasciitis. CONCLUSIONS Differences observed in clustering of strains based on functional groups of proteins correlate with phenotypes such as host tropism, capability to infect multiple hosts and drug resistance. Our method provides a solid basis towards large-scale prediction of phenotypes based on genomic information.
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Affiliation(s)
- Niels A Zondervan
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
- LifeGlimmer GmBH, Markelstraße 38, 12163, Berlin, Germany
| | - Maria Suarez-Diez
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
| | - Edoardo Saccenti
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands.
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30
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Luo H, Lin Y, Liu T, Lai FL, Zhang CT, Gao F, Zhang R. DEG 15, an update of the Database of Essential Genes that includes built-in analysis tools. Nucleic Acids Res 2021; 49:D677-D686. [PMID: 33095861 PMCID: PMC7779065 DOI: 10.1093/nar/gkaa917] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 09/30/2020] [Accepted: 10/06/2020] [Indexed: 12/21/2022] Open
Abstract
Essential genes refer to genes that are required by an organism to survive under specific conditions. Studies of the minimal-gene-set for bacteria have elucidated fundamental cellular processes that sustain life. The past five years have seen a significant progress in identifying human essential genes, primarily due to the successful use of CRISPR/Cas9 in various types of human cells. DEG 15, a new release of the Database of Essential Genes (www.essentialgene.org), has provided major advancements, compared to DEG 10. Specifically, the number of eukaryotic essential genes has increased by more than fourfold, and that of prokaryotic ones has more than doubled. Of note, the human essential-gene number has increased by more than tenfold. Moreover, we have developed built-in analysis modules by which users can perform various analyses, such as essential-gene distributions between bacterial leading and lagging strands, sub-cellular localization distribution, enrichment analysis of gene ontology and KEGG pathways, and generation of Venn diagrams to compare and contrast gene sets between experiments. Additionally, the database offers customizable BLAST tools for performing species- and experiment-specific BLAST searches. Therefore, DEG comprehensively harbors updated human-curated essential-gene records among prokaryotes and eukaryotes with built-in tools to enhance essential-gene analysis.
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Affiliation(s)
- Hao Luo
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Yan Lin
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Tao Liu
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Fei-Liao Lai
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Chun-Ting Zhang
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Feng Gao
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China.,Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Ren Zhang
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA
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31
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Sertbas M, Ulgen KO. Genome-Scale Metabolic Modeling for Unraveling Molecular Mechanisms of High Threat Pathogens. Front Cell Dev Biol 2020; 8:566702. [PMID: 33251208 PMCID: PMC7673413 DOI: 10.3389/fcell.2020.566702] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/30/2020] [Indexed: 12/14/2022] Open
Abstract
Pathogens give rise to a wide range of diseases threatening global health and hence drawing public health agencies' attention to establish preventative and curative solutions. Genome-scale metabolic modeling is ever increasingly used tool for biomedical applications including the elucidation of antibiotic resistance, virulence, single pathogen mechanisms and pathogen-host interaction systems. With this approach, the sophisticated cellular system of metabolic reactions inside the pathogens as well as between pathogen and host cells are represented in conjunction with their corresponding genes and enzymes. Along with essential metabolic reactions, alternate pathways and fluxes are predicted by performing computational flux analyses for the growth of pathogens in a very short time. The genes or enzymes responsible for the essential metabolic reactions in pathogen growth are regarded as potential drug targets, as a priori guide to researchers in the pharmaceutical field. Pathogens alter the key metabolic processes in infected host, ultimately the objective of these integrative constraint-based context-specific metabolic models is to provide novel insights toward understanding the metabolic basis of the acute and chronic processes of infection, revealing cellular mechanisms of pathogenesis, identifying strain-specific biomarkers and developing new therapeutic approaches including the combination drugs. The reaction rates predicted during different time points of pathogen development enable us to predict active pathways and those that only occur during certain stages of infection, and thus point out the putative drug targets. Among others, fatty acid and lipid syntheses reactions are recent targets of new antimicrobial drugs. Genome-scale metabolic models provide an improved understanding of how intracellular pathogens utilize the existing microenvironment of the host. Here, we reviewed the current knowledge of genome-scale metabolic modeling in pathogen cells as well as pathogen host interaction systems and the promising applications in the extension of curative strategies against pathogens for global preventative healthcare.
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Affiliation(s)
- Mustafa Sertbas
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey.,Department of Chemical Engineering, Istanbul Technical University, Istanbul, Turkey
| | - Kutlu O Ulgen
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey
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32
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Al-Tameemi H, Beavers WN, Norambuena J, Skaar EP, Boyd JM. Staphylococcus aureus lacking a functional MntABC manganese import system has increased resistance to copper. Mol Microbiol 2020; 115:554-573. [PMID: 33034093 DOI: 10.1111/mmi.14623] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/28/2020] [Accepted: 10/04/2020] [Indexed: 12/17/2022]
Abstract
S. aureus USA300 isolates utilize the copBL and copAZ gene products to prevent Cu intoxication. We created and examined a ΔcopAZ ΔcopBL mutant strain (cop-). The cop- strain was sensitive to Cu and accumulated intracellular Cu. We screened a transposon (Tn) mutant library in the cop- background and isolated strains with Tn insertions in the mntABC operon that permitted growth in the presence of Cu. The mutations were in mntA and they were recessive. Under the growth conditions utilized, MntABC functioned in manganese (Mn) import. When cultured with Cu, strains containing a mntA::Tn accumulated less Cu than the parent strain. Mn(II) supplementation improved growth when cop- was cultured with Cu and this phenotype was dependent upon the presence of MntR, which is a repressor of mntABC transcription. A ΔmntR strain had an increased Cu load and decreased growth in the presence of Cu, which was abrogated by the introduction of mntA::Tn. Over-expression of mntABC increased cellular Cu load and sensitivity to Cu. The presence of a mntA::Tn mutation protected iron-sulfur (FeS) enzymes from inactivation by Cu. The data presented are consistent with a model wherein defective MntABC results in decreased cellular Cu accumulation and protection to FeS enzymes from Cu poisoning.
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Affiliation(s)
- Hassan Al-Tameemi
- Department of Biochemistry and Microbiology, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
| | - William N Beavers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Javiera Norambuena
- Department of Biochemistry and Microbiology, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
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33
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Bockman MR, Mishra N, Aldrich CC. The Biotin Biosynthetic Pathway in Mycobacterium tuberculosis is a Validated Target for the Development of Antibacterial Agents. Curr Med Chem 2020; 27:4194-4232. [PMID: 30663561 DOI: 10.2174/0929867326666190119161551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/14/2018] [Accepted: 01/12/2019] [Indexed: 12/11/2022]
Abstract
Mycobacterium tuberculosis, responsible for Tuberculosis (TB), remains the leading cause of mortality among infectious diseases worldwide from a single infectious agent, with an estimated 1.7 million deaths in 2016. Biotin is an essential cofactor in M. tuberculosis that is required for lipid biosynthesis and gluconeogenesis. M. tuberculosis relies on de novo biotin biosynthesis to obtain this vital cofactor since it cannot scavenge sufficient biotin from a mammalian host. The biotin biosynthetic pathway in M. tuberculosis has been well studied and rigorously genetically validated providing a solid foundation for medicinal chemistry efforts. This review examines the mechanism and structure of the enzymes involved in biotin biosynthesis and ligation, summarizes the reported genetic validation studies of the pathway, and then analyzes the most promising inhibitors and natural products obtained from structure-based drug design and phenotypic screening.
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Affiliation(s)
- Matthew R Bockman
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Neeraj Mishra
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
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34
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Identification of a Novel LysR-Type Transcriptional Regulator in Staphylococcus aureus That Is Crucial for Secondary Tissue Colonization during Metastatic Bloodstream Infection. mBio 2020; 11:mBio.01646-20. [PMID: 32843554 PMCID: PMC7448277 DOI: 10.1128/mbio.01646-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Staphylococcus aureus is an important pathogen that can disseminate via the bloodstream and establish metastatic infections in distant organs. To achieve a better understanding of the bacterial factors facilitating the development of these metastatic infections, we used in this study a Staphylococcus aureus transposon mutant library in a murine model of intravenous infection, where bacteria first colonize the liver as the primary infection site and subsequently progress to secondary sites such as the kidney and bones. We identified a novel LysR-type transcriptional regulator (LTTR), which was specifically required by S. aureus for efficient colonization of secondary organs. We also determined the transcriptional activation as well as the regulon of LTTR, which suggests that this regulator is involved in the metabolic adaptation of S. aureus to the host microenvironment found in secondary infection sites. Staphylococcus aureus is a common cause of bacteremia that can lead to severe complications once the bacteria exit the bloodstream and establish infection in secondary organs. Despite its clinical relevance, little is known about the bacterial factors facilitating the development of these metastatic infections. Here, we used an S. aureus transposon mutant library coupled to transposon insertion sequencing (Tn-Seq) to identify genes that are critical for efficient bacterial colonization of secondary organs in a murine model of metastatic bloodstream infection. Our transposon screen identified a LysR-type transcriptional regulator (LTTR), which was required for efficient colonization of secondary organs such as the kidneys in infected mice. The critical role of LTTR in secondary organ colonization was confirmed using an isogenic mutant deficient in the expression of LTTR. To identify the set of genes controlled by LTTR, we used an S. aureus strain carrying the LTTR gene in an inducible expression plasmid. Gene expression analysis upon induction of LTTR showed increased transcription of genes involved in branched-chain amino acid biosynthesis, a methionine sulfoxide reductase, and a copper transporter as well as decreased transcription of genes coding for urease and components of pyrimidine nucleotides. Furthermore, we show that transcription of LTTR is repressed by glucose, is induced under microaerobic conditions, and required trace amounts of copper ions. Our data thus pinpoints LTTR as an important element that enables a rapid adaptation of S. aureus to the changing host microenvironment.
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35
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Hou YM, Masuda I, Foster LJ. tRNA methylation: An unexpected link to bacterial resistance and persistence to antibiotics and beyond. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1609. [PMID: 32533808 DOI: 10.1002/wrna.1609] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 02/02/2023]
Abstract
A major threat to public health is the resistance and persistence of Gram-negative bacteria to multiple drugs during antibiotic treatment. The resistance is due to the ability of these bacteria to block antibiotics from permeating into and accumulating inside the cell, while the persistence is due to the ability of these bacteria to enter into a nonreplicating state that shuts down major metabolic pathways but remains active in drug efflux. Resistance and persistence are permitted by the unique cell envelope structure of Gram-negative bacteria, which consists of both an outer and an inner membrane (OM and IM, respectively) that lay above and below the cell wall. Unexpectedly, recent work reveals that m1 G37 methylation of tRNA, at the N1 of guanosine at position 37 on the 3'-side of the tRNA anticodon, controls biosynthesis of both membranes and determines the integrity of cell envelope structure, thus providing a novel link to the development of bacterial resistance and persistence to antibiotics. The impact of m1 G37-tRNA methylation on Gram-negative bacteria can reach further, by determining the ability of these bacteria to exit from the persistence state when the antibiotic treatment is removed. These conceptual advances raise the possibility that successful targeting of m1 G37-tRNA methylation can provide new approaches for treating acute and chronic infections caused by Gram-negative bacteria. This article is categorized under: Translation > Translation Regulation RNA Processing > RNA Editing and Modification RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Isao Masuda
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Leonard J Foster
- Department of Biochemistry & Molecular Biology, and Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
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36
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Gajdiss M, Monk IR, Bertsche U, Kienemund J, Funk T, Dietrich A, Hort M, Sib E, Stinear TP, Bierbaum G. YycH and YycI Regulate Expression of Staphylococcus aureus Autolysins by Activation of WalRK Phosphorylation. Microorganisms 2020; 8:microorganisms8060870. [PMID: 32526915 PMCID: PMC7355866 DOI: 10.3390/microorganisms8060870] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus is a facultative pathogen that can encode numerous antibiotic resistance and immune evasion genes and can cause severe infections. Reduced susceptibility to last resort antibiotics such as vancomycin and daptomycin is often associated with mutations in walRK, an essential two-component regulatory system (TCS). This study focuses on the WalK accessory membrane proteins YycH and YycI and their influence on WalRK phosphorylation. Depletion of YycH and YycI by antisense RNA caused an impaired autolysis, indicating a positive regulatory function on WalK as has been previously described. Phosphorylation assays with full-length recombinant proteins in phospholipid liposomes showed that YycH and YycI stimulate WalK activity and that both regulatory proteins are needed for full activation of the WalK kinase. This was validated in vivo through examining the phosphorylation status of WalR using Phos-tag SDS-PAGE with a yycHI deletion mutant exhibiting reduced levels of phosphorylated WalR. In the yycHI knockdown strain, muropeptide composition of the cell wall was not affected, however, the wall teichoic acid content was increased. In conclusion, a direct modulation of WalRK phosphorylation activity by the accessory proteins YycH and YycI is reported both in vitro and in vivo. Taken together, our results show that YycH and YycI are important in the direct regulation of WalRK-dependent cell wall metabolism.
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Affiliation(s)
- Mike Gajdiss
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Ian R. Monk
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3010, Australia; (I.R.M.); (T.P.S.)
| | - Ute Bertsche
- Department of Infection Biology, University of Tuebingen, 72076 Tuebingen, Germany;
| | - Janina Kienemund
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Tanja Funk
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Alina Dietrich
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Michael Hort
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Esther Sib
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3010, Australia; (I.R.M.); (T.P.S.)
| | - Gabriele Bierbaum
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
- Correspondence:
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37
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An evolutionary path to altered cofactor specificity in a metalloenzyme. Nat Commun 2020; 11:2738. [PMID: 32483131 PMCID: PMC7264356 DOI: 10.1038/s41467-020-16478-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 04/29/2020] [Indexed: 11/28/2022] Open
Abstract
Almost half of all enzymes utilize a metal cofactor. However, the features that dictate the metal utilized by metalloenzymes are poorly understood, limiting our ability to manipulate these enzymes for industrial and health-associated applications. The ubiquitous iron/manganese superoxide dismutase (SOD) family exemplifies this deficit, as the specific metal used by any family member cannot be predicted. Biochemical, structural and paramagnetic analysis of two evolutionarily related SODs with different metal specificity produced by the pathogenic bacterium Staphylococcus aureus identifies two positions that control metal specificity. These residues make no direct contacts with the metal-coordinating ligands but control the metal’s redox properties, demonstrating that subtle architectural changes can dramatically alter metal utilization. Introducing these mutations into S. aureus alters the ability of the bacterium to resist superoxide stress when metal starved by the host, revealing that small changes in metal-dependent activity can drive the evolution of metalloenzymes with new cofactor specificity. Many metalloenzymes are highly specific for their cognate metal ion but the molecular principles underlying this specificity often remain unclear. Here, the authors characterize the structural and biochemical basis for the different metal specificity of two evolutionarily related superoxide dismutases.
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38
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Abstract
CRISPR-Cas systems have been engineered as powerful tools to control gene expression in bacteria. The most common strategy relies on the use of Cas effectors modified to bind target DNA without introducing DNA breaks. These effectors can either block the RNA polymerase or recruit it through activation domains. Here, we discuss the mechanistic details of how Cas effectors can modulate gene expression by blocking transcription initiation or acting as transcription roadblocks. CRISPR-Cas tools can be further engineered to obtain fine-tuned control of gene expression or target multiple genes simultaneously. Several caveats in using these tools have also been revealed, including off-target effects and toxicity, making it important to understand the design rules of engineered CRISPR-Cas effectors in bacteria. Alternatively, some types of CRISPR-Cas systems target RNA and could be used to block gene expression at the posttranscriptional level. Finally, we review applications of these tools in high-throughput screens and the progress and challenges in introducing CRISPR knockdown to other species, including nonmodel bacteria with industrial or clinical relevance. A deep understanding of how CRISPR-Cas systems can be harnessed to control gene expression in bacteria and build powerful tools will certainly open novel research directions.
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Affiliation(s)
- Antoine Vigouroux
- Synthetic Biology, Institut Pasteur, Paris, France
- Microbial Morphogenesis and Growth, Institut Pasteur, Paris, France
| | - David Bikard
- Synthetic Biology, Institut Pasteur, Paris, France
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Li L, Wang G, Cheung A, Abdelhady W, Seidl K, Xiong YQ. MgrA Governs Adherence, Host Cell Interaction, and Virulence in a Murine Model of Bacteremia Due to Staphylococcus aureus. J Infect Dis 2020; 220:1019-1028. [PMID: 31177268 DOI: 10.1093/infdis/jiz219] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/26/2019] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND MgrA is an important global virulence gene regulator in Staphylococcus aureus. In the present study, the role of mgrA in host-pathogen interactions related to virulence was explored in both methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains. METHODS In vitro susceptibilities to human defense peptides (HDPs), adherence to fibronectin (Fn) and endothelial cells (ECs), EC damage, α-toxin production, expression of global regulator (eg, agr RNAIII) and its downstream effectors (eg, α-toxin [hla] and Fn binding protein A [fnbA]), MgrA binding to fnbA promoter, and the effect on HDP-induced mprF and dltA expression were analyzed. The impact of mgrA on virulence was evaluated using a mouse bacteremia model. RESULTS mgrA mutants displayed significantly higher susceptibility to HDPs, which might be related to the decreased HDP-induced mprF and dltA expression but decreased Fn and EC adherence, EC damage, α-toxin production, agr RNAIII, hla and fnbA expression, and attenuated virulence in the bacteremia model as compared to their respective parental and mgrA-complemented strains. Importantly, direct binding of MgrA to the fnbA promoter was observed. CONCLUSIONS These results suggest that mgrA mediates host-pathogen interactions and virulence and may provide a novel therapeutic target for invasive S. aureus infections.
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Affiliation(s)
- Liang Li
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance
| | - Genzhu Wang
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance
| | | | - Wessam Abdelhady
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance
| | - Kati Seidl
- University Hospital of Zurich, Switzerland
| | - Yan Q Xiong
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance.,David Geffen School of Medicine at UCLA, Los Angeles, California
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40
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Collins MM, Behera RK, Pallister KB, Evans TJ, Burroughs O, Flack C, Guerra FE, Pullman W, Cone B, Dankoff JG, Nygaard TK, Brinsmade SR, Voyich JM. The Accessory Gene saeP of the SaeR/S Two-Component Gene Regulatory System Impacts Staphylococcus aureus Virulence During Neutrophil Interaction. Front Microbiol 2020; 11:561. [PMID: 32390958 PMCID: PMC7189620 DOI: 10.3389/fmicb.2020.00561] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/16/2020] [Indexed: 01/04/2023] Open
Abstract
Staphylococcus aureus (S. aureus) causes a range of diseases ranging from superficial skin and soft-tissue infections to invasive and life-threatening conditions (Klevens et al., 2007; Kobayashi et al., 2015). S. aureus utilizes the Sae sensory system to adapt to neutrophil challenge. Although the roles of the SaeR response regulator and its cognate sensor kinase SaeS have been demonstrated to be critical for surviving neutrophil interaction and for causing infection, the roles for the accessory proteins SaeP and SaeQ remain incompletely defined. To characterize the functional role of these proteins during innate immune interaction, we generated isogenic deletion mutants lacking these accessory genes in USA300 (USA300ΔsaeP and USA300ΔsaeQ). S. aureus survival was increased following phagocytosis of USA300ΔsaeP compared to USA300 by neutrophils. Additionally, secreted extracellular proteins produced by USA300ΔsaeP cells caused significantly more plasma membrane damage to human neutrophils than extracellular proteins produced by USA300 cells. Deletion of saeQ resulted in a similar phenotype, but effects did not reach significance during neutrophil interaction. The enhanced cytotoxicity of USA300ΔsaeP cells toward human neutrophils correlated with an increased expression of bi-component leukocidins known to target these immune cells. A saeP and saeQ double mutant (USA300ΔsaePQ) showed a significant increase in survival following neutrophil phagocytosis that was comparable to the USA300ΔsaeP single mutant and increased the virulence of USA300 during murine bacteremia. These data provide evidence that SaeP modulates the Sae-mediated response of S. aureus against human neutrophils and suggest that saeP and saeQ together impact pathogenesis in vivo.
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Affiliation(s)
- Madison M Collins
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Ranjan K Behera
- Department of Biology, Georgetown University, Washington, DC, United States
| | - Kyler B Pallister
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Tyler J Evans
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Owen Burroughs
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Caralyn Flack
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Fermin E Guerra
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Willis Pullman
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Brock Cone
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Jennifer G Dankoff
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Tyler K Nygaard
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Shaun R Brinsmade
- Department of Biology, Georgetown University, Washington, DC, United States
| | - Jovanka M Voyich
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
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41
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Rao RT, Sivakumar N, Jayakumar K. Analyses of Livestock-Associated Staphylococcus aureus Pan-Genomes Suggest Virulence Is Not Primary Interest in Evolution of Its Genome. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 23:224-236. [PMID: 31009331 DOI: 10.1089/omi.2019.0005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Staphylococcus aureus is not only part of normal flora but also an opportunistic pathogen relevant to microbial genomics, public health, and veterinary medicine. In addition to being a well-known human pathogen, S. aureus causes various infections in economically important livestock animals such as cows, sheep, goats, and pigs. There are very few studies that have examined the pan-genome of S. aureus or the host-specific strains' pan-genomes. We report on livestock-associated S. aureus' (LA-SA) pan-genome and suggest that virulence is not the primary interest in evolution of its genome. LA-SA' complete genomes were retrieved from the NCBI and pan-genome was constructed by high-speed Roary pipeline. The pan-genome size was 4637 clusters, whereas 42.46% of the pan-genome was associated with the core genome. We found 1268 genes were associated with the strain-unique genome, and the remaining 1432 cluster with the accessory genome. COG (clusters of orthologous group of proteins) analysis of the core genes revealed 34% of clusters related to metabolism responsible for amino acid and inorganic ion transport (COG categories E and P), followed by carbohydrate metabolism (category G). Virulent gene analysis revealed the core genes responsible for antiphagocytosis and iron uptake. The fluidity of pan-genome was calculated as 0.082 ± 0.025. Importantly, the positive selection analysis suggested a slower rate of evolution among the LA-SA genomes. We call for comparative microbial and pan-genome research between human and LA-SA that can help further understand the evolution of virulence and thus inform future microbial diagnostics and drug discovery.
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Affiliation(s)
- Relangi Tulasi Rao
- 1 Department of Animal Behaviour & Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai, Tamil Nadu, India
| | - Natesan Sivakumar
- 2 Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai, Tamil Nadu, India
| | - Kannan Jayakumar
- 1 Department of Animal Behaviour & Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai, Tamil Nadu, India
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Hayes AJ, Satiaputra J, Sternicki LM, Paparella AS, Feng Z, Lee KJ, Blanco-Rodriguez B, Tieu W, Eijkelkamp BA, Shearwin KE, Pukala TL, Abell AD, Booker GW, Polyak SW. Advanced Resistance Studies Identify Two Discrete Mechanisms in Staphylococcus aureus to Overcome Antibacterial Compounds that Target Biotin Protein Ligase. Antibiotics (Basel) 2020; 9:antibiotics9040165. [PMID: 32268615 PMCID: PMC7235819 DOI: 10.3390/antibiotics9040165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/03/2020] [Accepted: 04/04/2020] [Indexed: 11/16/2022] Open
Abstract
Biotin protein ligase (BPL) inhibitors are a novel class of antibacterial that target clinically important methicillin-resistant Staphylococcus aureus (S. aureus). In S. aureus, BPL is a bifunctional protein responsible for enzymatic biotinylation of two biotin-dependent enzymes, as well as serving as a transcriptional repressor that controls biotin synthesis and import. In this report, we investigate the mechanisms of action and resistance for a potent anti-BPL, an antibacterial compound, biotinyl-acylsulfamide adenosine (BASA). We show that BASA acts by both inhibiting the enzymatic activity of BPL in vitro, as well as functioning as a transcription co-repressor. A low spontaneous resistance rate was measured for the compound (<10−9) and whole-genome sequencing of strains evolved during serial passaging in the presence of BASA identified two discrete resistance mechanisms. In the first, deletion of the biotin-dependent enzyme pyruvate carboxylase is proposed to prioritize the utilization of bioavailable biotin for the essential enzyme acetyl-CoA carboxylase. In the second, a D200E missense mutation in BPL reduced DNA binding in vitro and transcriptional repression in vivo. We propose that this second resistance mechanism promotes bioavailability of biotin by derepressing its synthesis and import, such that free biotin may outcompete the inhibitor for binding BPL. This study provides new insights into the molecular mechanisms governing antibacterial activity and resistance of BPL inhibitors in S. aureus.
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Affiliation(s)
- Andrew J. Hayes
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Jiulia Satiaputra
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Louise M. Sternicki
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Ashleigh S. Paparella
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Zikai Feng
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Kwang J. Lee
- School of Physical Sciences, University of Adelaide, South Australia 5005, Australia; (K.J.L.); (B.B.-R.); (W.T.); (T.L.P.); (A.D.A.)
| | - Beatriz Blanco-Rodriguez
- School of Physical Sciences, University of Adelaide, South Australia 5005, Australia; (K.J.L.); (B.B.-R.); (W.T.); (T.L.P.); (A.D.A.)
| | - William Tieu
- School of Physical Sciences, University of Adelaide, South Australia 5005, Australia; (K.J.L.); (B.B.-R.); (W.T.); (T.L.P.); (A.D.A.)
| | - Bart A. Eijkelkamp
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Keith E. Shearwin
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Tara L. Pukala
- School of Physical Sciences, University of Adelaide, South Australia 5005, Australia; (K.J.L.); (B.B.-R.); (W.T.); (T.L.P.); (A.D.A.)
| | - Andrew D. Abell
- School of Physical Sciences, University of Adelaide, South Australia 5005, Australia; (K.J.L.); (B.B.-R.); (W.T.); (T.L.P.); (A.D.A.)
- Centre for Nanoscale BioPhotonics (CNBP), University of Adelaide, Adelaide, SA 5005, Australia
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Grant W. Booker
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
| | - Steven W. Polyak
- School of Biological Sciences, University of Adelaide, South Australia 5005, Australia; (A.J.H.); (J.S.); (L.M.S.); (A.S.P.); (Z.F.); (B.A.E.); (K.E.S.); (G.W.B.)
- Correspondence: ; Tel.: +61883021603
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Gelin M, Paoletti J, Nahori MA, Huteau V, Leseigneur C, Jouvion G, Dugué L, Clément D, Pons JL, Assairi L, Pochet S, Labesse G, Dussurget O. From Substrate to Fragments to Inhibitor Active In Vivo against Staphylococcus aureus. ACS Infect Dis 2020; 6:422-435. [PMID: 32017533 DOI: 10.1021/acsinfecdis.9b00368] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Antibiotic resistance is a worldwide threat due to the decreasing supply of new antimicrobials. Novel targets and innovative strategies are urgently needed to generate pathbreaking drug compounds. NAD kinase (NADK) is essential for growth in most bacteria, as it supports critical metabolic pathways. Here, we report the discovery of a new class of antibacterials that targets bacterial NADK. We generated a series of small synthetic adenine derivatives to screen those harboring promising substituents in order to guide efficient fragment linking. This led to NKI1, a new lead compound inhibiting NADK that showed in vitro bactericidal activity against Staphylococcus aureus. In a murine model of infection, NKI1 restricted survival of the bacteria, including methicillin-resistant S. aureus. Collectively, these findings identify bacterial NADK as a potential drug target and NKI1 as a lead compound in the treatment of staphylococcal infections.
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Affiliation(s)
- Muriel Gelin
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université Montpellier, 29 route de Navacelles, 34090 Montpellier, France
| | - Julie Paoletti
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Marie-Anne Nahori
- Unité des Toxines Bactériennes, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Valérie Huteau
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Clarisse Leseigneur
- Unité de Recherche Yersinia, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 35 rue Hélène Brion, 75013 Paris, France
| | - Grégory Jouvion
- Unité de Neuropathologie Expérimentale, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
- Sorbonne Université, INSERM UMR S933, Unité de Génétique Médicale, Hôpital Armand Trousseau, APHP, 26 Avenue du Dr Arnold Netter, 75012 Paris, France
| | - Laurence Dugué
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - David Clément
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 35 rue Hélène Brion, 75013 Paris, France
| | - Jean-Luc Pons
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université Montpellier, 29 route de Navacelles, 34090 Montpellier, France
| | - Liliane Assairi
- INSERM U759, Institut Curie, Centre Universitaire Paris Sud, 91405 Orsay, France
| | - Sylvie Pochet
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Gilles Labesse
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université Montpellier, 29 route de Navacelles, 34090 Montpellier, France
| | - Olivier Dussurget
- Unité de Recherche Yersinia, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 35 rue Hélène Brion, 75013 Paris, France
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44
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Recent development in acetyl-CoA carboxylase inhibitors and their potential as novel drugs. Future Med Chem 2020; 12:533-561. [PMID: 32048880 DOI: 10.4155/fmc-2019-0312] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Acetyl-CoA carboxylase (ACC), a critical enzyme in the regulation of fatty acid synthesis and metabolism, has emerged as an attractive target for a plethora of emerging diseases, such as diabetes mellitus, nonalcoholic fatty liver disease, cancer, bacterial infections and so on. With decades of efforts in medicinal chemistry, significant progress has been made toward the design and discovery of a considerable number of inhibitors of this enzyme. In this review, we not only clarify the role of ACC in emerging diseases, but also summarize recent developments of potent ACC inhibitors and discuss their molecular mechanisms of action and potentials as novel drugs as well as future perspectives toward the design and discovery of novel ACC inhibitors.
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An integrated computational and experimental study to investigate Staphylococcus aureus metabolism. NPJ Syst Biol Appl 2020; 6:3. [PMID: 32001720 PMCID: PMC6992624 DOI: 10.1038/s41540-019-0122-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 12/19/2019] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus is a metabolically versatile pathogen that colonizes nearly all organs of the human body. A detailed and comprehensive knowledge of staphylococcal metabolism is essential to understand its pathogenesis. To this end, we have reconstructed and experimentally validated an updated and enhanced genome-scale metabolic model of S. aureus USA300_FPR3757. The model combined genome annotation data, reaction stoichiometry, and regulation information from biochemical databases and previous strain-specific models. Reactions in the model were checked and fixed to ensure chemical balance and thermodynamic consistency. To further refine the model, growth assessment of 1920 nonessential mutants from the Nebraska Transposon Mutant Library was performed, and metabolite excretion profiles of important mutants in carbon and nitrogen metabolism were determined. The growth and no-growth inconsistencies between the model predictions and in vivo essentiality data were resolved using extensive manual curation based on optimization-based reconciliation algorithms. Upon intensive curation and refinements, the model contains 863 metabolic genes, 1379 metabolites (including 1159 unique metabolites), and 1545 reactions including transport and exchange reactions. To improve the accuracy and predictability of the model to environmental changes, condition-specific regulation information curated from the existing knowledgebase was incorporated. These critical additions improved the model performance significantly in capturing gene essentiality, substrate utilization, and metabolite production capabilities and increased the ability to generate model-based discoveries of therapeutic significance. Use of this highly curated model will enhance the functional utility of omics data, and therefore, serve as a resource to support future investigations of S. aureus and to augment staphylococcal research worldwide. Integration of in vivo experiment with a newly developed model of Staphylococcus aureus metabolism helps explore its metabolic versatility. A multidisciplinary team led by Rajib Saha at the University of Nebraska developed a new genome-scale metabolic model of the multi-drug resistant pathogen S. aureus by combining genome annotation data, reaction stoichiometry, and condition- and mutant-specific regulations from biochemical databases and previous strain-specific models. Extensive manual curation and incorporation of newly generated experimental data on growth and metabolite production improved the accuracy and predictability of the model and increased its ability to generate model-based discoveries of therapeutic significance. Use of this highly curated model will enhance the functional utility of omics data and, therefore, serve as a resource to support future investigations of S. aureus and to augment staphylococcal research worldwide.
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46
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Hernández-Tamayo R, Oviedo-Bocanegra LM, Fritz G, Graumann PL. Symmetric activity of DNA polymerases at and recruitment of exonuclease ExoR and of PolA to the Bacillus subtilis replication forks. Nucleic Acids Res 2019; 47:8521-8536. [PMID: 31251806 PMCID: PMC6895272 DOI: 10.1093/nar/gkz554] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 06/06/2019] [Accepted: 06/24/2019] [Indexed: 11/14/2022] Open
Abstract
DNA replication forks are intrinsically asymmetric and may arrest during the cell cycle upon encountering modifications in the DNA. We have studied real time dynamics of three DNA polymerases and an exonuclease at a single molecule level in the bacterium Bacillus subtilis. PolC and DnaE work in a symmetric manner and show similar dwell times. After addition of DNA damage, their static fractions and dwell times decreased, in agreement with increased re-establishment of replication forks. Only a minor fraction of replication forks showed a loss of active polymerases, indicating relatively robust activity during DNA repair. Conversely, PolA, homolog of polymerase I and exonuclease ExoR were rarely present at forks during unperturbed replication but were recruited to replications forks after induction of DNA damage. Protein dynamics of PolA or ExoR were altered in the absence of each other during exponential growth and during DNA repair, indicating overlapping functions. Purified ExoR displayed exonuclease activity and preferentially bound to DNA having 5′ overhangs in vitro. Our analyses support the idea that two replicative DNA polymerases work together at the lagging strand whilst only PolC acts at the leading strand, and that PolA and ExoR perform inducible functions at replication forks during DNA repair.
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Affiliation(s)
- Rogelio Hernández-Tamayo
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Hans-Meerwein-Straße 6, 35043 Marburg, Germany.,Department of Chemistry, Philipps Universität Marburg, Hans-Meerwein-Straße 6, 35043 Marburg, Germany
| | - Luis M Oviedo-Bocanegra
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Hans-Meerwein-Straße 6, 35043 Marburg, Germany.,Department of Chemistry, Philipps Universität Marburg, Hans-Meerwein-Straße 6, 35043 Marburg, Germany
| | - Georg Fritz
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Hans-Meerwein-Straße 6, 35043 Marburg, Germany.,Department of Physics, Philipps Universität Marburg, Renthof 5, 35032 Marburg, Germany
| | - Peter L Graumann
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Hans-Meerwein-Straße 6, 35043 Marburg, Germany.,Department of Chemistry, Philipps Universität Marburg, Hans-Meerwein-Straße 6, 35043 Marburg, Germany
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47
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Jaroensuk J, Wong YH, Zhong W, Liew CW, Maenpuen S, Sahili AE, Atichartpongkul S, Chionh YH, Nah Q, Thongdee N, McBee ME, Prestwich EG, DeMott MS, Chaiyen P, Mongkolsuk S, Dedon PC, Lescar J, Fuangthong M. Crystal structure and catalytic mechanism of the essential m 1G37 tRNA methyltransferase TrmD from Pseudomonas aeruginosa. RNA (NEW YORK, N.Y.) 2019; 25:1481-1496. [PMID: 31399541 PMCID: PMC6795141 DOI: 10.1261/rna.066746.118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 07/28/2019] [Indexed: 06/10/2023]
Abstract
The tRNA (m1G37) methyltransferase TrmD catalyzes m1G formation at position 37 in many tRNA isoacceptors and is essential in most bacteria, which positions it as a target for antibiotic development. In spite of its crucial role, little is known about TrmD in Pseudomonas aeruginosa (PaTrmD), an important human pathogen. Here we present detailed structural, substrate, and kinetic properties of PaTrmD. The mass spectrometric analysis confirmed the G36G37-containing tRNAs Leu(GAG), Leu(CAG), Leu(UAG), Pro(GGG), Pro(UGG), Pro(CGG), and His(GUG) as PaTrmD substrates. Analysis of steady-state kinetics with S-adenosyl-l-methionine (SAM) and tRNALeu(GAG) showed that PaTrmD catalyzes the two-substrate reaction by way of a ternary complex, while isothermal titration calorimetry revealed that SAM and tRNALeu(GAG) bind to PaTrmD independently, each with a dissociation constant of 14 ± 3 µM. Inhibition by the SAM analog sinefungin was competitive with respect to SAM (Ki = 0.41 ± 0.07 µM) and uncompetitive for tRNA (Ki = 6.4 ± 0.8 µM). A set of crystal structures of the homodimeric PaTrmD protein bound to SAM and sinefungin provide the molecular basis for enzyme competitive inhibition and identify the location of the bound divalent ion. These results provide insights into PaTrmD as a potential target for the development of antibiotics.
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Affiliation(s)
- Juthamas Jaroensuk
- Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Yee Hwa Wong
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Wenhe Zhong
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Chong Wai Liew
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Somchart Maenpuen
- Department of Biochemistry, Faculty of Science, Burapha University, Chonburi 20131, Thailand
| | - Abbas E Sahili
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | | | - Yok Hian Chionh
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Qianhui Nah
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Narumon Thongdee
- Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Megan E McBee
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Erin G Prestwich
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Michael S DeMott
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
- Department of Biotechnology, Faculty of Sciences, Mahidol University, Bangkok 10400, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), Bangkok 10400, Thailand
| | - Peter C Dedon
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Julien Lescar
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Mayuree Fuangthong
- Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), Bangkok 10400, Thailand
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48
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Kawano M, Morohashi S, Oda K, Ishikawa M, Fujita S, Saito M. Artificial small RNA-mediated growth inhibition in Escherichia coli and Salmonella enterica serovar Typhimurium. Biochem Biophys Res Commun 2019; 521:577-583. [PMID: 31679698 DOI: 10.1016/j.bbrc.2019.10.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 10/05/2019] [Indexed: 11/25/2022]
Abstract
We developed a synthetic RNA approach to identify growth inhibition sequences by cloning random 24-nucleotide (nt) sequences into an arabinose-inducible expression vector. This vector expressed a small RNA (sRNA) of ∼140 nt containing a 24 nt random sequence insert. After transforming Escherichia coli with the vector, 10 out of 954 transformants showed strong growth defect phenotypes and two clones caused cell lysis. We then examined growth inhibition phenotypes in the Salmonella Typhimurium LT2 strain using the twelve sRNAs that exerted an inhibitory effect on E. coli growth. Three of these clones showed strong growth inhibition phenotypes in S. Typhimurium LT2. The most effective sRNA contained the same insert (N1) in both bacteria. The 24 nt random sequence insert of N1 was abundant in guanine residues (ten out of 24 nt), and other random sequences causing growth defects were also highly enriched for guanine (G) nucleotides. We, therefore, generated clones that express sRNAs containing a stretch of 16 to 24 continuous guanine sequences (poly-G16, -G18, -G20, -G22, and -G24). All of these clones induced growth inhibition in both liquid and agar plate media and the poly-G20 clone showed the strongest effect in E. coli. These results demonstrate that our sRNA expression system can be used to identify nucleotide sequences that are potential candidates for oligonucleotide antimicrobial drugs.
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Affiliation(s)
- Mitsuoki Kawano
- Department of Human Nutrition, Faculty of Contemporary Life Science, Chugokugakuen University, Okayama, Japan; Department of Microbiology, Kawasaki Medical School, Kurashiki, Japan.
| | - Shota Morohashi
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Kohei Oda
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Masataka Ishikawa
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Shouta Fujita
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Mineki Saito
- Department of Microbiology, Kawasaki Medical School, Kurashiki, Japan
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Modulating Pathogenesis with Mobile-CRISPRi. J Bacteriol 2019; 201:JB.00304-19. [PMID: 31481541 PMCID: PMC6805112 DOI: 10.1128/jb.00304-19] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/24/2019] [Indexed: 12/13/2022] Open
Abstract
Conditionally essential (CE) genes are required by pathogenic bacteria to establish and maintain infections. CE genes encode virulence factors, such as secretion systems and effector proteins, as well as biosynthetic enzymes that produce metabolites not found in the host environment. Due to their outsized importance in pathogenesis, CE gene products are attractive targets for the next generation of antimicrobials. However, the precise manipulation of CE gene expression in the context of infection is technically challenging, limiting our ability to understand the roles of CE genes in pathogenesis and accordingly design effective inhibitors. We previously developed a suite of CRISPR interference-based gene knockdown tools that are transferred by conjugation and stably integrate into bacterial genomes that we call Mobile-CRISPRi. Here, we show the efficacy of Mobile-CRISPRi in controlling CE gene expression in an animal infection model. We optimize Mobile-CRISPRi in Pseudomonas aeruginosa for use in a murine model of pneumonia by tuning the expression of CRISPRi components to avoid nonspecific toxicity. As a proof of principle, we demonstrate that knock down of a CE gene encoding the type III secretion system (T3SS) activator ExsA blocks effector protein secretion in culture and attenuates virulence in mice. We anticipate that Mobile-CRISPRi will be a valuable tool to probe the function of CE genes across many bacterial species and pathogenesis models.IMPORTANCE Antibiotic resistance is a growing threat to global health. To optimize the use of our existing antibiotics and identify new targets for future inhibitors, understanding the fundamental drivers of bacterial growth in the context of the host immune response is paramount. Historically, these genetic drivers have been difficult to manipulate precisely, as they are requisite for pathogen survival. Here, we provide the first application of Mobile-CRISPRi to study conditionally essential virulence genes in mouse models of lung infection through partial gene perturbation. We envision the use of Mobile-CRISPRi in future pathogenesis models and antibiotic target discovery efforts.
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Zalis EA, Nuxoll AS, Manuse S, Clair G, Radlinski LC, Conlon BP, Adkins J, Lewis K. Stochastic Variation in Expression of the Tricarboxylic Acid Cycle Produces Persister Cells. mBio 2019; 10:e01930-19. [PMID: 31530676 PMCID: PMC6751062 DOI: 10.1128/mbio.01930-19] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/05/2019] [Indexed: 02/07/2023] Open
Abstract
Chronic bacterial infections are difficult to eradicate, though they are caused primarily by drug-susceptible pathogens. Antibiotic-tolerant persisters largely account for this paradox. In spite of their significance in the recalcitrance of chronic infections, the mechanism of persister formation is poorly understood. We previously reported that a decrease in ATP levels leads to drug tolerance in Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus We reasoned that stochastic fluctuation in the expression of tricarboxylic acid (TCA) cycle enzymes can produce cells with low energy levels. S. aureus knockouts in glutamate dehydrogenase, 2-oxoketoglutarate dehydrogenase, succinyl coenzyme A (CoA) synthetase, and fumarase have low ATP levels and exhibit increased tolerance of fluoroquinolone, aminoglycoside, and β-lactam antibiotics. Fluorescence-activated cell sorter (FACS) analysis of TCA genes shows a broad Gaussian distribution in a population, with differences of over 3 orders of magnitude in the levels of expression between individual cells. Sorted cells with low levels of TCA enzyme expression have an increased tolerance of antibiotic treatment. These findings suggest that fluctuations in the levels of expression of energy-generating components serve as a mechanism of persister formation.IMPORTANCE Persister cells are rare phenotypic variants that are able to survive antibiotic treatment. Unlike resistant bacteria, which have specific mechanisms to prevent antibiotics from binding to their targets, persisters evade antibiotic killing by entering a tolerant nongrowing state. Persisters have been implicated in chronic infections in multiple species, and growing evidence suggests that persister cells are responsible for many cases of antibiotic treatment failure. New antibiotic treatment strategies aim to kill tolerant persister cells more effectively, but the mechanism of tolerance has remained unclear until now.
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Affiliation(s)
- Eliza A Zalis
- Department of Biology, Antimicrobial Discovery Center, Northeastern University, Boston, Massachusetts, USA
| | - Austin S Nuxoll
- Department of Biology, Antimicrobial Discovery Center, Northeastern University, Boston, Massachusetts, USA
| | - Sylvie Manuse
- Department of Biology, Antimicrobial Discovery Center, Northeastern University, Boston, Massachusetts, USA
| | - Geremy Clair
- Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Lauren C Radlinski
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Brian P Conlon
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Joshua Adkins
- Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Kim Lewis
- Department of Biology, Antimicrobial Discovery Center, Northeastern University, Boston, Massachusetts, USA
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