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Bassetti M, Cascio A, De Rosa FG, Meschiari M, Parrella R, Petrosillo N, Armuzzi A, Caprioli F, Dentali F, Pani M, Pilotto A, Restelli U, Sanguinetti M. Management of Clostridioides difficile infection: an Italian Delphi consensus. J Antimicrob Chemother 2024:dkae179. [PMID: 39008427 DOI: 10.1093/jac/dkae179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024] Open
Abstract
BACKGROUND Clostridioides difficile infection (CDI), a leading cause of nosocomial deaths, is a microbiota-mediated disease. As such, the use of broader spectrum antibiotics, such as vancomycin and metronidazole, can prime the gastrointestinal tract to become more prone to CDI recurrences. Fidaxomicin, a narrow-spectrum antibiotic, has been demonstrated to be superior in preventing recurrence and in preserving the intestinal microbiota; however, widespread employment worldwide has been hindered due to high acquisition costs. OBJECTIVES To integrate the currently available guidelines on the management of CDI and to shed light on the timeliest employment of fidaxomicin. METHODS An expert panel was gathered to obtain consensus using Delphi methodology on a series of statements regarding the management of CDI and on appropriate antibiotic use. RESULTS Consensus was reached on 21 of the 25 statements addressing the management of CDI. CONCLUSIONS Delphi methodology was used to achieve consensus on the management of CDI, on the identification of patients at risk of recurrences or severe infection, and on the most appropriate use of fidaxomicin, with the final aim of fostering clinical practice application of treatment algorithms proposed by previous guidelines, in absolute synergy. It could be an important tool to promote more appropriate and cost-effective CDI treatments in European settings with limited resources, like Italy.
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Affiliation(s)
- Matteo Bassetti
- Infectious Diseases Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Antonio Cascio
- Department PROMISE-Infectious and Tropical Diseases Unit, AOU Policlinico "P. Giaccone", University of Palermo, 90127 Palermo, Italy
| | | | - Marianna Meschiari
- Department of Infectious Diseases, Azienda Ospedaliero-Universitaria di Modena, Policlinico di Modena, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Roberto Parrella
- Unit of Respiratory Infectious Diseases, Cotugno Hospital, Azienda Ospedaliera dei Colli, 80131 Naples, Italy
| | - Nicola Petrosillo
- Infection Prevention and Control Service, Fondazione Policlinico Universitario Campus Bio-Medico, 00127 Rome, Italy
| | - Alessandro Armuzzi
- IBD Unit, IRCCS Humanitas Research Hospital, Via A. Manzoni 56, Rozzano, 20089 Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
| | - Flavio Caprioli
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20133 Milan, Italy
- Gastroenterology and Endoscopy Unit, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico di Milano, 20122 Milan, Italy
| | - Francesco Dentali
- Division of Internal Medicine, Medical Center, Ospedale di Circolo & Fondazione Macchi, ASST Sette Laghi, 21100 Varese, Italy
- Department of Medicine and Surgery, Insubria University, 21100 Varese, Italy
| | - Marcello Pani
- Hospital Pharmacy, Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Alberto Pilotto
- Department of Interdisciplinary Medicine, 'Aldo Moro' University of Bari, 70121 Bari, Italy
- Geriatrics Unit, Department of Geriatric Care, Neurology and Rehabilitation, Galliera Hospitals, 16128 Genova, Italy
| | | | - Maurizio Sanguinetti
- Department of Laboratory and Infectious Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo A. Gemelli 8, 00168 Rome, Italy
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2
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Saecker RM, Mueller AU, Malone B, Chen J, Budell WC, Dandey VP, Maruthi K, Mendez JH, Molina N, Eng ET, Yen LY, Potter CS, Carragher B, Darst SA. Early intermediates in bacterial RNA polymerase promoter melting visualized by time-resolved cryo-electron microscopy. Nat Struct Mol Biol 2024:10.1038/s41594-024-01349-9. [PMID: 38951624 DOI: 10.1038/s41594-024-01349-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 06/06/2024] [Indexed: 07/03/2024]
Abstract
During formation of the transcription-competent open complex (RPo) by bacterial RNA polymerases (RNAPs), transient intermediates pile up before overcoming a rate-limiting step. Structural descriptions of these interconversions in real time are unavailable. To address this gap, here we use time-resolved cryogenic electron microscopy (cryo-EM) to capture four intermediates populated 120 ms or 500 ms after mixing Escherichia coli σ70-RNAP and the λPR promoter. Cryo-EM snapshots revealed that the upstream edge of the transcription bubble unpairs rapidly, followed by stepwise insertion of two conserved nontemplate strand (nt-strand) bases into RNAP pockets. As the nt-strand 'read-out' extends, the RNAP clamp closes, expelling an inhibitory σ70 domain from the active-site cleft. The template strand is fully unpaired by 120 ms but remains dynamic, indicating that yet unknown conformational changes complete RPo formation in subsequent steps. Given that these events likely describe DNA opening at many bacterial promoters, this study provides insights into how DNA sequence regulates steps of RPo formation.
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Affiliation(s)
- Ruth M Saecker
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
| | - Andreas U Mueller
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
| | - Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
- Memorial Sloan Kettering Cancer Center, Sloan Kettering Institute, New York, NY, USA
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - William C Budell
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Venkata P Dandey
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
- National Institute of Environmental Health Sciences, Durham, NC, USA
| | - Kashyap Maruthi
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Joshua H Mendez
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Nina Molina
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
| | - Edward T Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Laura Y Yen
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Clinton S Potter
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Chan Zuckerberg Imaging Institute, San Francisco, CA, USA
| | - Bridget Carragher
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Chan Zuckerberg Imaging Institute, San Francisco, CA, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA.
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3
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Ferrara I, Chesnokov GA, Dittmann S, Blacque O, Sievers S, Gademann K. Formal Single Atom Editing of the Glycosylated Natural Product Fidaxomicin Improves Acid Stability and Retains Antibiotic Activity. JACS AU 2024; 4:2267-2280. [PMID: 38938792 PMCID: PMC11200244 DOI: 10.1021/jacsau.4c00206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/15/2024] [Accepted: 05/06/2024] [Indexed: 06/29/2024]
Abstract
Fidaxomicin (Fdx) constitutes a glycosylated natural product with excellent antibacterial activity against various Gram-positive bacteria but is approved only for Clostridioides difficile infections. Poor water solubility and acid lability preclude its use for other infections. Herein, we describe our strategy to overcome the acid lability by introducing acid-stable S-linked glycosides. We describe the direct, diastereoselective modification of unprotected Fdx without the need to avoid air or moisture. Using our newly established approach, Fdx was converted to the single atom exchanged analogue S-Fdx, in which the acid labile O-glycosidic bond to the noviose sugar was replaced by the acid stable S-glycosidic bond. Studies of the antibacterial activity of a structurally diverse set of thioglycoside derivatives revealed high potency of acyl derivatives of S-Fdx against Clostridioides difficile (MIC range: 0.12-4 μg/mL) and excellent potency against Clostridium perfringens (MIC range: 0.06-0.5 μg/mL).
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Affiliation(s)
- Isabella Ferrara
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Gleb A. Chesnokov
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Silvia Dittmann
- Department
for Microbial Physiology and Molecular Biology, Institute of Microbiology,
Center for Functional Genomics of Microbes, University of Greifswald, Felix-Hausdorff-Strasse 8, 17489 Greifswald, Germany
| | - Olivier Blacque
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Susanne Sievers
- Department
for Microbial Physiology and Molecular Biology, Institute of Microbiology,
Center for Functional Genomics of Microbes, University of Greifswald, Felix-Hausdorff-Strasse 8, 17489 Greifswald, Germany
| | - Karl Gademann
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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4
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Saba J, Flores K, Marshall B, Engstrom MD, Peng Y, Garje AS, Comstock L, Landick R. Bacteroides expand the functional versatility of a universal transcription factor and transcribed DNA to program capsule diversity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.21.599965. [PMID: 38948710 PMCID: PMC11213015 DOI: 10.1101/2024.06.21.599965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Human gut Bacteroides species encode numerous (eight or more) tightly regulated capsular polysaccharides (CPS). Specialized paralogs of the universal transcription elongation factor NusG, called UpxY (Y), and an anti-Y UpxZ (Z) are encoded by the first two genes of each CPS operon. The Y-Z regulators combine with promoter inversions to limit CPS transcription to a single operon in most cells. Y enhances transcript elongation whereas Z inhibits noncognate Ys. How Y distinguishes among cognate CPS operons and how Z inhibits only noncognate Ys are unknown. Using in-vivo nascent-RNA sequencing and promoter-less in vitro transcription (PIVoT), we establish that Y recognizes a paused RNA polymerase via sequences in both the exposed non-template DNA and the upstream duplex DNA. Y association is aided by novel 'pause-then-escape' nascent RNA hairpins. Z binds non-cognate Ys to directly inhibit Y association. This Y-Z hierarchical regulatory program allows Bacteroides to create CPS subpopulations for optimal fitness.
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Affiliation(s)
- Jason Saba
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
- Microbiology Doctoral Training Program, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Katia Flores
- Department of Microbiology, University of Chicago, Chicago, IL, 60637, USA
- Duchossois Family Institute, University of Chicago, Chicago, IL 60637, USA
| | - Bailey Marshall
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
- Cell and Molecular Biology Training Program, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Michael D. Engstrom
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Yikai Peng
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Atharv S. Garje
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
- Genetics Training Program, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Laurie Comstock
- Department of Microbiology, University of Chicago, Chicago, IL, 60637, USA
- Duchossois Family Institute, University of Chicago, Chicago, IL 60637, USA
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706, USA
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI 53706, USA
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5
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Yuan L, Liu Q, Xu L, Wu B, Feng Y. Structural basis of promoter recognition by Staphylococcus aureus RNA polymerase. Nat Commun 2024; 15:4850. [PMID: 38844782 PMCID: PMC11156646 DOI: 10.1038/s41467-024-49229-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 05/28/2024] [Indexed: 06/09/2024] Open
Abstract
Bacterial RNAP needs to form holoenzyme with σ factors to initiate transcription. While Staphylococcus aureus σA controls housekeeping functions, S. aureus σB regulates virulence, biofilm formation, persistence, cell internalization, membrane transport, and antimicrobial resistance. Besides the sequence difference, the spacers between the -35 element and -10 element of σB regulated promoters are shorter than those of σA regulated promoters. Therefore, how σB recognizes and initiates transcription from target promoters can not be inferred from that of the well studied σ. Here, we report the cryo-EM structures of S. aureus RNAP-promoter open complexes comprising σA and σB, respectively. Structural analyses, in combination with biochemical experiments, reveal the structural basis for the promoter specificity of S. aureus transcription. Although the -10 element of σA regulated promoters is recognized by domain σA2 as single-stranded DNA, the -10 element of σB regulated promoters is co-recognized by domains σB2 and σB3 as double-stranded DNA, accounting for the short spacers of σB regulated promoters. S. aureus RNAP is a validated target of antibiotics, and our structures pave the way for rational drug design targeting S. aureus RNAP.
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Affiliation(s)
- Linggang Yuan
- Department of Biophysics, and Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qingyang Liu
- Department of Biophysics, and Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Liqiao Xu
- Department of Biophysics, and Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Bing Wu
- Department of Gastroenterology and Hepatology, Minhang Hospital, Fudan University, Shanghai, China
- Institute of Fudan-Minhang Academic Health System, Minhang Hospital, Fudan University, Shanghai, China
| | - Yu Feng
- Department of Biophysics, and Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
- Key Laboratory for Diagnosis and Treatment of Physic-Chemical and Aging Injury Diseases of Zhejiang Province, Hangzhou, China.
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6
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Kolte B, Nübel U. Genetic determinants of resistance to antimicrobial therapeutics are rare in publicly available Clostridioides difficile genome sequences. J Antimicrob Chemother 2024; 79:1320-1328. [PMID: 38598696 PMCID: PMC11144481 DOI: 10.1093/jac/dkae101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/18/2024] [Indexed: 04/12/2024] Open
Abstract
OBJECTIVES To determine the frequencies and clonal distributions of putative genetic determinants of resistance to antimicrobials applied for treatment of Clostridioides difficile infection (CDI), as documented in the genomic record. METHODS We scanned 26 557 C. difficile genome sequences publicly available from the EnteroBase platform for plasmids, point mutations and gene truncations previously reported to reduce susceptibility to vancomycin, fidaxomicin or metronidazole, respectively. We measured the antimicrobial susceptibility of 143 selected C. difficile isolates. RESULTS The frequency of mutations causing reduced susceptibility to vancomycin and metronidazole, respectively, increased strongly after 2000, peaking at up to 52% of all sequenced C. difficile genomes. However, both mutations declined sharply more recently, reflecting major changes in CDI epidemiology. We detected mutations associated with fidaxomicin resistance in several major genotypes, but found no evidence of international spread of resistant clones. The pCD-METRO plasmid, conferring metronidazole resistance, was detected in a single previously unreported C. difficile isolate, recovered from a hospital patient in Germany in 2008. The pX18-498 plasmid, putatively associated with decreased vancomycin susceptibility, was confined to related, recent isolates from the USA. Phenotype measurements confirmed that most of those genetic features were useful predictors of antibiotic susceptibility, even though ranges of MICs typically overlapped among isolates with and without specific mutations. CONCLUSIONS Genomic data suggested that resistance to therapeutic antimicrobial drugs is rare in C. difficile. Public antimicrobial resistance marker databases were not equipped to detect most of the genetic determinants relevant to antibiotic therapy of CDI.
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Affiliation(s)
- Baban Kolte
- Leibniz Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Microbial Genome Research, Inhoffenstr. 7B, 38124, Braunschweig, Germany
- Technical University Braunschweig, Institute of Microbiology, Braunschweig, Germany
| | - Ulrich Nübel
- Leibniz Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Microbial Genome Research, Inhoffenstr. 7B, 38124, Braunschweig, Germany
- Technical University Braunschweig, Institute of Microbiology, Braunschweig, Germany
- German Center for Infection Research (DZIF), Partner Site Braunschweig-Hannover, Braunschweig, Germany
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7
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Saecker RM, Mueller AU, Malone B, Chen J, Budell WC, Dandey VP, Maruthi K, Mendez JH, Molina N, Eng ET, Yen LY, Potter CS, Carragher B, Darst SA. Early intermediates in bacterial RNA polymerase promoter melting visualized by time-resolved cryo-electron microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.13.584744. [PMID: 38559232 PMCID: PMC10979975 DOI: 10.1101/2024.03.13.584744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
During formation of the transcription-competent open complex (RPo) by bacterial RNA polymerases (RNAP), transient intermediates pile up before overcoming a rate-limiting step. Structural descriptions of these interconversions in real time are unavailable. To address this gap, time-resolved cryo-electron microscopy (cryo-EM) was used to capture four intermediates populated 120 or 500 milliseconds (ms) after mixing Escherichia coli σ70-RNAP and the λPR promoter. Cryo-EM snapshots revealed the upstream edge of the transcription bubble unpairs rapidly, followed by stepwise insertion of two conserved nontemplate strand (nt-strand) bases into RNAP pockets. As nt-strand "read-out" extends, the RNAP clamp closes, expelling an inhibitory σ70 domain from the active-site cleft. The template strand is fully unpaired by 120 ms but remains dynamic, indicating yet unknown conformational changes load it in subsequent steps. Because these events likely describe DNA opening at many bacterial promoters, this study provides needed insights into how DNA sequence regulates steps of RPo formation.
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Affiliation(s)
- Ruth M. Saecker
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - Andreas U. Mueller
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - William C. Budell
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Venkata P. Dandey
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Kashyap Maruthi
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Joshua H. Mendez
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Nina Molina
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - Edward T. Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Laura Y. Yen
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Clinton S. Potter
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY USA
| | - Bridget Carragher
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY USA
| | - Seth A. Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
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8
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Dureja C, Rutherford JT, Pavel FB, Norseeda K, Prah I, Sun D, Hevener KE, Hurdle JG. In vivo evaluation of Clostridioides difficile enoyl-ACP reductase II (FabK) inhibition by phenylimidazole unveils a promising narrow-spectrum antimicrobial strategy. Antimicrob Agents Chemother 2024; 68:e0122223. [PMID: 38265216 PMCID: PMC10916379 DOI: 10.1128/aac.01222-23] [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: 09/21/2023] [Accepted: 12/18/2023] [Indexed: 01/25/2024] Open
Abstract
Clostridioides difficile infection (CDI) is a leading cause of hospital-acquired diarrhea, which often stems from disruption of the gut microbiota by broad-spectrum antibiotics. The increasing prevalence of antibiotic-resistant C. difficile strains, combined with disappointing clinical trial results for recent antibiotic candidates, underscores the urgent need for novel CDI antibiotics. To this end, we investigated C. difficile enoyl ACP reductase (CdFabK), a crucial enzyme in de novo fatty acid synthesis, as a drug target for microbiome-sparing antibiotics. To test this concept, we evaluated the efficacy and in vivo spectrum of activity of the phenylimidazole analog 296, which is validated to inhibit intracellular CdFabK. Against major CDI-associated ribotypes 296 had an Minimum inhibitory concentration (MIC90) of 2 µg/mL, which was comparable to vancomycin (1 µg/mL), a standard of care antibiotic. In addition, 296 achieved high colonic concentrations and displayed dosed-dependent efficacy in mice with colitis CDI. Mice that were given 296 retained colonization resistance to C. difficile and had microbiomes that resembled the untreated mice. Conversely, both vancomycin and fidaxomicin induced significant changes to mice microbiomes, in a manner consistent with prior reports. CdFabK, therefore, represents a potential target for microbiome-sparing CDI antibiotics, with phenylimidazoles providing a good chemical starting point for designing such agents.
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Affiliation(s)
- Chetna Dureja
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Jacob T. Rutherford
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Fahad B.A. Pavel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Krissada Norseeda
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, Hawaii, USA
| | - Isaac Prah
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Dianqing Sun
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, Hawaii, USA
| | - Kirk E. Hevener
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Julian G. Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
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9
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Markantonis JE, Fallon JT, Madan R, Alam MZ. Clostridioides difficile Infection: Diagnosis and Treatment Challenges. Pathogens 2024; 13:118. [PMID: 38392856 PMCID: PMC10891949 DOI: 10.3390/pathogens13020118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
Clostridioides difficile is the most important cause of healthcare-associated diarrhea in the United States. The high incidence and recurrence rates of C. difficile infection (CDI), associated with high morbidity and mortality, pose a public health challenge. Although antibiotics targeting C. difficile bacteria are the first treatment choice, antibiotics also disrupt the indigenous gut flora and, therefore, create an environment that is favorable for recurrent CDI. The challenge of treating CDI is further exacerbated by the rise of antibiotic-resistant strains of C. difficile, placing it among the top five most urgent antibiotic resistance threats in the USA. The evolution of antibiotic resistance in C. difficile involves the acquisition of new resistance mechanisms, which can be shared among various bacterial species and different C. difficile strains within clinical and community settings. This review provides a summary of commonly used diagnostic tests and antibiotic treatment strategies for CDI. In addition, it discusses antibiotic treatment and its resistance mechanisms. This review aims to enhance our current understanding and pinpoint knowledge gaps in antimicrobial resistance mechanisms in C. difficile, with an emphasis on CDI therapies.
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Affiliation(s)
- John E. Markantonis
- Department of Pathology and Laboratory Medicine, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA; (J.E.M.); (J.T.F.)
| | - John T. Fallon
- Department of Pathology and Laboratory Medicine, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA; (J.E.M.); (J.T.F.)
| | - Rajat Madan
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
- Veterans Affairs Medical Center, Cincinnati, OH 45220, USA
| | - Md Zahidul Alam
- Department of Pathology and Laboratory Medicine, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA; (J.E.M.); (J.T.F.)
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10
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Walsh L, Lavelle A, O’Connor PM, Hill C, Ross RP. Comparison of fidaxomicin, thuricin CD, vancomycin and nisin highlights the narrow spectrum nature of thuricin CD. Gut Microbes 2024; 16:2342583. [PMID: 38722061 PMCID: PMC11085969 DOI: 10.1080/19490976.2024.2342583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 04/09/2024] [Indexed: 05/12/2024] Open
Abstract
Vancomycin and metronidazole are commonly used treatments for Clostridioides difficile infection (CDI). However, these antibiotics have been associated with high levels of relapse in patients. Fidaxomicin is a new treatment for CDI that is described as a narrow spectrum antibiotic that is minimally active on the commensal bacteria of the gut microbiome. The aim of this study was to compare the effect of fidaxomicin on the human gut microbiome with a number of narrow (thuricin CD) and broad spectrum (vancomycin and nisin) antimicrobials. The spectrum of activity of each antimicrobial was tested against 47 bacterial strains by well-diffusion assay. Minimum inhibitory concentrations (MICs) were calculated against a select number of these strains. Further, a pooled fecal slurry of 6 donors was prepared and incubated for 24 h with 100 µM of each antimicrobial in a mini-fermentation system together with a no-treatment control. Fidaxomicin, vancomycin, and nisin were active against most gram positive bacteria tested in vitro, although fidaxomicin and vancomycin produced larger zones of inhibition compared to nisin. In contrast, the antimicrobial activity of thuricin CD was specific to C. difficile and some Bacillus spp. The MICs showed similar results. Thuricin CD exhibited low MICs (<3.1 µg/mL) for C. difficile and Bacillus firmus, whereas fidaxomicin, vancomycin, and nisin demonstrated lower MICs for all other strains tested when compared to thuricin CD. The narrow spectrum of thuricin CD was also observed in the gut model system. We conclude that the spectrum of activity of fidaxomicin is comparable to that of the broad-spectrum antibiotic vancomycin in vitro and the broad spectrum bacteriocin nisin in a complex community.
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Affiliation(s)
- L. Walsh
- School of Microbiology, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - A. Lavelle
- School of Microbiology, University College Cork, Cork, Ireland
| | - PM O’Connor
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Teagasc Food Research Centre, Cork, Ireland
| | - C. Hill
- School of Microbiology, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - R. P. Ross
- School of Microbiology, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
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11
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Jung E, Kraimps A, Dittmann S, Griesser T, Costafrolaz J, Mattenberger Y, Jurt S, Viollier PH, Sander P, Sievers S, Gademann K. Phenolic Substitution in Fidaxomicin: A Semisynthetic Approach to Antibiotic Activity Across Species. Chembiochem 2023; 24:e202300570. [PMID: 37728121 DOI: 10.1002/cbic.202300570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/21/2023]
Abstract
Fidaxomicin (Fdx) is a natural product antibiotic with potent activity against Clostridioides difficile and other Gram-positive bacteria such as Mycobacterium tuberculosis. Only a few Fdx derivatives have been synthesized and examined for their biological activity in the 50 years since its discovery. Fdx has a well-studied mechanism of action, namely inhibition of the bacterial RNA polymerase. Yet, the targeted organisms harbor different target protein sequences, which poses a challenge for the rational development of new semisynthetic Fdx derivatives. We introduced substituents on the two phenolic hydroxy groups of Fdx and evaluated the resulting trends in antibiotic activity against M. tuberculosis, C. difficile, and the Gram-negative model organism Caulobacter crescentus. As suggested by the target protein structures, we identified the preferable derivatisation site for each organism. The derivative ortho-methyl Fdx also exhibited activity against the Gram-negative C. crescentus wild type, a first for fidaxomicin antibiotics. These insights will guide the synthesis of next-generation fidaxomicin antibiotics.
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Affiliation(s)
- Erik Jung
- Department of Chemistry, University of Zurich, 8057, Zürich, Switzerland
| | - Anastassia Kraimps
- Department of Chemistry, University of Zurich, 8057, Zürich, Switzerland
| | - Silvia Dittmann
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Tizian Griesser
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Jordan Costafrolaz
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Yves Mattenberger
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Simon Jurt
- Department of Chemistry, University of Zurich, 8057, Zürich, Switzerland
| | - Patrick H Viollier
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Peter Sander
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Susanne Sievers
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Karl Gademann
- Department of Chemistry, University of Zurich, 8057, Zürich, Switzerland
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12
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Xie H, Ruan JY, Bu QT, Li YP, Su YT, Zhao QW, Du YL, Li YQ. Transcriptional regulation of the fidaxomicin gene cluster and cellular development in Actinoplanes deccanensis YP-1 by the pleiotropic regulator MtrA. Microbiol Spectr 2023; 11:e0270223. [PMID: 37966201 PMCID: PMC10714768 DOI: 10.1128/spectrum.02702-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/06/2023] [Indexed: 11/16/2023] Open
Abstract
IMPORTANCE Cascade regulation networks are almost present in various kinds of microorganisms, but locating and systematically elucidating specific pleiotropic regulators related to a certain gene cluster can be a tricky problem. Here, based on the promoter of the fidaxomicin pathway-specific regulator FadR1, we utilized a "DNA to Proteins" affinity purification method and captured a global regulator MtrA, which positively regulates fidaxomicin biosynthesis. In the mtrA overexpressed strain, the production of fidaxomicin was improved by 37% compared to the native strain. Then, we combined the "Protein to DNAs" affinity purification method (DAP-seq) with the results of RNA-seq and systematically elucidated the primary and secondary metabolic processes in which MtrA directly or indirectly participates. Thus, our work brought up a new way to improve fidaxomicin production from the perspective of global regulation and analyzed the regulatory mechanism of MtrA. Meanwhile, we provided a novel methodology for the research of cascade regulation networks and vital secondary metabolites.
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Affiliation(s)
- Huang Xie
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Institute of Pharmaceutical Biotechnology, Hangzhou, China
| | - Jing-Yi Ruan
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Institute of Pharmaceutical Biotechnology, Hangzhou, China
| | - Qing-Ting Bu
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Institute of Pharmaceutical Biotechnology, Hangzhou, China
| | - Yue-Ping Li
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Institute of Pharmaceutical Biotechnology, Hangzhou, China
| | - Yi-Ting Su
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Institute of Pharmaceutical Biotechnology, Hangzhou, China
| | - Qing-Wei Zhao
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi-Ling Du
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Institute of Pharmaceutical Biotechnology, Hangzhou, China
| | - Yong-Quan Li
- First Affiliated Hospital and Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Institute of Pharmaceutical Biotechnology, Hangzhou, China
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13
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Alam MZ, Markantonis JE, Fallon JT. Host Immune Responses to Clostridioides difficile Infection and Potential Novel Therapeutic Approaches. Trop Med Infect Dis 2023; 8:506. [PMID: 38133438 PMCID: PMC10747268 DOI: 10.3390/tropicalmed8120506] [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: 10/30/2023] [Revised: 11/17/2023] [Accepted: 11/19/2023] [Indexed: 12/23/2023] Open
Abstract
Clostridioides difficile infection (CDI) is a leading nosocomial infection, posing a substantial public health challenge within the United States and globally. CDI typically occurs in hospitalized elderly patients who have been administered antibiotics; however, there has been a rise in the occurrence of CDI in the community among young adults who have not been exposed to antibiotics. C. difficile releases toxins, which damage large intestinal epithelium, leading to toxic megacolon, sepsis, and even death. Unfortunately, existing antibiotic therapies do not always prevent these consequences, with up to one-third of treated patients experiencing a recurrence of the infection. Host factors play a crucial role in the pathogenesis of CDI, and accumulating evidence shows that modulation of host immune responses may potentially alter the disease outcome. In this review, we provide an overview of our current knowledge regarding the role of innate and adaptive immune responses on CDI outcomes. Moreover, we present a summary of non-antibiotic microbiome-based therapies that can effectively influence host immune responses, along with immunization strategies that are intended to tackle both the treatment and prevention of CDI.
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Affiliation(s)
- Md Zahidul Alam
- Department of Pathology and Laboratory Medicine, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA; (J.E.M.); (J.T.F.)
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14
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Jensen D, Ruiz Manzano A, Rector M, Tomko E, Record M, Galburt E. High-throughput, fluorescent-aptamer-based measurements of steady-state transcription rates for the Mycobacterium tuberculosis RNA polymerase. Nucleic Acids Res 2023; 51:e99. [PMID: 37739412 PMCID: PMC10602862 DOI: 10.1093/nar/gkad761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/04/2023] [Accepted: 09/11/2023] [Indexed: 09/24/2023] Open
Abstract
The first step in gene expression is the transcription of DNA sequences into RNA. Regulation at the level of transcription leads to changes in steady-state concentrations of RNA transcripts, affecting the flux of downstream functions and ultimately cellular phenotypes. Changes in transcript levels are routinely followed in cellular contexts via genome-wide sequencing techniques. However, in vitro mechanistic studies of transcription have lagged with respect to throughput. Here, we describe the use of a real-time, fluorescent-aptamer-based method to quantitate steady-state transcription rates of the Mycobacterium tuberculosis RNA polymerase. We present clear controls to show that the assay specifically reports on promoter-dependent, full-length RNA transcription rates that are in good agreement with the kinetics determined by gel-resolved, α-32P NTP incorporation experiments. We illustrate how the time-dependent changes in fluorescence can be used to measure regulatory effects of nucleotide concentrations and identity, RNAP and DNA concentrations, transcription factors, and antibiotics. Our data showcase the ability to easily perform hundreds of parallel steady-state measurements across varying conditions with high precision and reproducibility to facilitate the study of the molecular mechanisms of bacterial transcription.
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Affiliation(s)
- Drake Jensen
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
| | - Ana Ruiz Manzano
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
| | - Maxwell Rector
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Eric J Tomko
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
| | - M Thomas Record
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Eric A Galburt
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
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15
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Pal R, Seleem MN. Antisense inhibition of RNA polymerase α subunit of Clostridioides difficile. Microbiol Spectr 2023; 11:e0175523. [PMID: 37772833 PMCID: PMC10581251 DOI: 10.1128/spectrum.01755-23] [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: 04/26/2023] [Accepted: 08/14/2023] [Indexed: 09/30/2023] Open
Abstract
Clostridioides difficile, the causative agent of antibiotic-associated diarrhea and pseudomembranous colitis, has emerged as a major enteric pathogen in recent years. Antibiotic treatment perturbs the gut microbiome homeostasis, which facilitates the colonization and proliferation of the pathogen in the host intestine. Paradoxically, the clinical repertoire for C. difficile infection includes the antibiotics vancomycin and/or fidaxomicin. The current therapies do not address the perturbed gut microbiome, which supports the recurrence of infection after cessation of antibiotic therapy. Peptide nucleic acids (PNAs) are novel alternatives to traditional antimicrobial therapy capable of forming strong and stable complexes with RNA and DNA, thus permitting targeted inhibition of specific genes. Here, we report a novel PNA that can target the RNA polymerase α subunit (rpoA) in C. difficile. The designed anti-rpoA construct inhibited clinical isolates of C. difficile (minimum inhibitory concentration values ranged between 4 and 8 µM) and exhibited bactericidal activity. Furthermore, silencing of the rpoA gene suppressed the expression of genes that encode virulence factors [toxin A (tcdA), toxin B (tcdB)] in C. difficile, and the gene that encodes the transcription factor stage 0 sporulation protein (spoOA). Interestingly, the efficacy of the designed PNA conjugate remained unaffected even when tested at different pH levels and against a high inoculum of the pathogen. The rpoA-TAT conjugate was very specific against C. difficile and did not inhibit members of the beneficial gut microflora. Taken altogether, our study confirms that the rpoA gene can be a promising narrow-spectrum therapeutic target to curb C. difficile infection. IMPORTANCE The widespread use of antibiotics can destroy beneficial intestinal microflora, opening the door for spores of Clostridioides difficile to run rampant in the digestive system, causing life-threatening diarrhea. Alternative approaches to target this deadly pathogen are urgently needed. We utilized targeted therapeutics called peptide nucleic acids (PNAs) to inhibit gene expression in C. difficile. Inhibition of the RNA polymerase α subunit gene (rpoA) by PNA was found to be lethal for C. difficile and could also disarm its virulence factors. Additionally, antisense inhibition of the C. difficile rpoA gene did not impact healthy microflora. We also propose a novel approach to manipulate gene expression in C. difficile without the need for established genetic tools.
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Affiliation(s)
- Rusha Pal
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Mohamed N. Seleem
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
- Center for Emerging Zoonotic and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
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16
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Dureja C, Rutherford JT, Pavel FBA, Norseeda K, Prah I, Sun D, Hevener KE, Hurdle JG. In vivo evaluation of Clostridioides difficile enoyl-ACP reductase II (FabK) Inhibition by phenylimidazole unveils a promising narrow-spectrum antimicrobial strategy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.22.559005. [PMID: 37790427 PMCID: PMC10543012 DOI: 10.1101/2023.09.22.559005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Clostridioides difficile infection (CDI) is a leading cause of hospital-acquired diarrhea, which often stem from disruption of the gut microbiota by broad-spectrum antibiotics. The increasing prevalence of antibiotic-resistant C. difficile strains, combined with disappointing clinical trials results for recent antibiotic candidates, underscore the urgent need for novel CDI antibiotics. To this end, we investigated C. difficile enoyl ACP reductase (CdFabK), a crucial enzyme in de novo fatty acid synthesis, as a drug target for microbiome-sparing antibiotics. To test this concept, we evaluated the efficacy and in vivo spectrum of activity of the phenylimidazole analog 296, which is validated to inhibit intracellular CdFabK. Against major CDI-associated ribotypes 296 had an MIC90 of 2 μg/ml, which was comparable to vancomycin (1 μg/ml), a standard of care antibiotic. In addition, 296 achieved high colonic concentrations and displayed dosed-dependent efficacy in mice with colitis CDI. Mice that were given 296 retained colonization resistance to C. difficile and had microbiomes that resembled the untreated mice. Conversely, both vancomycin and fidaxomicin induced significant changes to mice microbiomes, in a manner consistent with prior reports. CdFabK therefore represents a potential target for microbiome-sparing CDI antibiotics, with phenylimidazoles providing a good chemical starting point for designing such agents.
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Affiliation(s)
- Chetna Dureja
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
| | - Jacob T. Rutherford
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
| | - Fahad B. A. Pavel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, Tennessee 38105, USA
| | - Krissada Norseeda
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, Hawaii 96720, USA
| | - Isaac Prah
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
| | - Dianqing Sun
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, Hawaii 96720, USA
| | - Kirk E. Hevener
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, Tennessee 38105, USA
| | - Julian G. Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
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17
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Hu X, Dong R, Huang S, Zeng Y, Zhan W, Gao X, Tian D, Peng J, Xu J, Wang T, Zhang Y, Wang X, Zhang X, Liu J, Guang B, Yang T. CDBN-YGXZ, a Novel Small-Molecule Drug, Shows Efficacy against Clostridioides difficile Infection and Recurrence in Mouse and Hamster Infection Models. Antimicrob Agents Chemother 2023; 67:e0170422. [PMID: 37052498 PMCID: PMC10190532 DOI: 10.1128/aac.01704-22] [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: 12/22/2022] [Accepted: 03/01/2023] [Indexed: 04/14/2023] Open
Abstract
Clostridioides difficile infection (CDI) causes severe diarrhea and colitis, leading to significant morbidity, mortality, and high medical costs worldwide. Oral vancomycin, a first-line treatment for CDI, is associated with a high risk of recurrence, necessitating novel therapies for primary and recurrent CDI. A novel small-molecule compound, CDBN-YGXZ, was synthesized by modifying the benzene ring of nitazoxanide with lauric acid. The mechanism of action of CDBN-YGXZ was validated using a pyruvate:ferredoxin/flavodoxin oxidoreductase (PFOR) inhibition assay. The efficacy of CDBN-YGXZ was evaluated using the MIC test and CDI infection model in mice and hamsters. Furthermore, metagenomics was used to reveal the underlying reasons for the effective reduction or prevention of CDI after CDBN-YGXZ treatment. The inhibitory activity against PFOR induced by CDBN-YGXZ. MIC tests showed that the in vitro activity of CDBN-YGXZ against C. difficile ranging from 0.1 to 1.5 μg/mL. In the mouse and hamster CDI models, CDBN-YGXZ provided protection during both treatment and relapse, while vancomycin treatment resulted in severe relapse and significant clinical scores. Compared with global effects on the indigenous gut microbiota induced by vancomycin, CDBN-YGXZ treatment had a mild influence on gut microbes, thus resulting in the disappearance or reduction of CDI recurrence. CDBN-YGXZ displayed potent activity against C. difficile in vitro and in vivo, reducing or preventing relapse in infected animals, which could merit further development as a potential drug candidate for treating CDI.
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Affiliation(s)
- Xiaojun Hu
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Renhan Dong
- Chengdu Biobel Biotechnology Co., Ltd., Chengdu, Sichuan Province, China
| | - Sheng Huang
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Yisheng Zeng
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Wei Zhan
- Chengdu Biobel Biotechnology Co., Ltd., Chengdu, Sichuan Province, China
| | - Xiaofang Gao
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Dong Tian
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Jian Peng
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Jiewei Xu
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Ting Wang
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Yaying Zhang
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Xiaohui Wang
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Xiaoxia Zhang
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jin Liu
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Bing Guang
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
- Chengdu Biobel Biotechnology Co., Ltd., Chengdu, Sichuan Province, China
| | - Tai Yang
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan Province, China
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18
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Wang L, Zhu M, Zhang Q, Zhai S, Zhu Y, Zhang H, Zhang C. Biosynthetic Diversification of Fidaxomicin Aglycones by Heterologous Expression and Promoter Refactoring. JOURNAL OF NATURAL PRODUCTS 2023; 86:986-993. [PMID: 37042607 DOI: 10.1021/acs.jnatprod.3c00001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Fidaxomicin (Dificid) is a commercial macrolide antibiotic for treating Clostridium difficile infection. Total synthesis of fidaxomicin and its aglycone had been achieved through different synthetic schemes. In this study, an alternative biological route to afford the unique 18-membered macrolactone aglycone of fidaxomicin was developed. The promoter refactored fidaxomicin biosynthetic gene cluster from Dactylosporangium aurantiacum was expressed in the commonly used host Streptomyces albus J1074, thereby delivering five structurally diverse fidaxomicin aglycones with the corresponding titers ranging from 4.9 to 15.0 mg L-1. In general, these results validated a biological strategy to construct and diversify fidaxomicin aglycones on the basis of promoter refactoring and heterologous expression.
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Affiliation(s)
- Lijuan Wang
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
| | - Mengyi Zhu
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
| | - Qingbo Zhang
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
- University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, People's Republic of China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, People's Republic of China
- Sanya Institute of Ocean Eco-Environmental Engineering, Yazhou Scientific Bay, Sanya 572000, People's Republic of China
| | - Shilan Zhai
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
- University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, People's Republic of China
| | - Yiguang Zhu
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
- University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, People's Republic of China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, People's Republic of China
- Sanya Institute of Ocean Eco-Environmental Engineering, Yazhou Scientific Bay, Sanya 572000, People's Republic of China
| | - Haibo Zhang
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
- University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, People's Republic of China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, People's Republic of China
- Sanya Institute of Ocean Eco-Environmental Engineering, Yazhou Scientific Bay, Sanya 572000, People's Republic of China
| | - Changsheng Zhang
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
- University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, People's Republic of China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, People's Republic of China
- Sanya Institute of Ocean Eco-Environmental Engineering, Yazhou Scientific Bay, Sanya 572000, People's Republic of China
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19
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Baranova AA, Alferova VA, Korshun VA, Tyurin AP. Modern Trends in Natural Antibiotic Discovery. Life (Basel) 2023; 13:life13051073. [PMID: 37240718 DOI: 10.3390/life13051073] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/10/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
Natural scaffolds remain an important basis for drug development. Therefore, approaches to natural bioactive compound discovery attract significant attention. In this account, we summarize modern and emerging trends in the screening and identification of natural antibiotics. The methods are divided into three large groups: approaches based on microbiology, chemistry, and molecular biology. The scientific potential of the methods is illustrated with the most prominent and recent results.
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Affiliation(s)
- Anna A Baranova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia
- Gause Institute of New Antibiotics, Bolshaya Pirogovskaya 11, 119021 Moscow, Russia
| | - Vera A Alferova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia
- Gause Institute of New Antibiotics, Bolshaya Pirogovskaya 11, 119021 Moscow, Russia
| | - Vladimir A Korshun
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia
| | - Anton P Tyurin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia
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20
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Jensen D, Manzano AR, Rector M, Tomko EJ, Record MT, Galburt EA. High-throughput, fluorescent-aptamer-based measurements of steady-state transcription rates for Mycobacterium tuberculosis RNA polymerase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.13.532464. [PMID: 36993414 PMCID: PMC10054983 DOI: 10.1101/2023.03.13.532464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The first step in gene expression is the transcription of DNA sequences into RNA. Regulation at the level of transcription leads to changes in steady-state concentrations of RNA transcripts, affecting the flux of downstream functions and ultimately cellular phenotypes. Changes in transcript levels are routinely followed in cellular contexts via genome-wide sequencing techniques. However, in vitro mechanistic studies of transcription have lagged with respect to throughput. Here, we describe the use of a real-time, fluorescent-aptamer-based method to quantitate steady-state transcription rates of the Mycobacterium tuberculosis RNA polymerase. We present clear controls to show that the assay specifically reports on promoter-dependent, full-length RNA transcription rates that are in good agreement with the kinetics determined by gel-resolved, α- 32 P NTP incorporation experiments. We illustrate how the time-dependent changes in fluorescence can be used to measure regulatory effects of nucleotide concentrations and identity, RNAP and DNA concentrations, transcription factors, and antibiotics. Our data showcase the ability to easily perform hundreds of parallel steady-state measurements across varying conditions with high precision and reproducibility to facilitate the study of the molecular mechanisms of bacterial transcription. Significance Statement RNA polymerase transcription mechanisms have largely been determined from in vitro kinetic and structural biology methods. In contrast to the limited throughput of these approaches, in vivo RNA sequencing provides genome-wide measurements but lacks the ability to dissect direct biochemical from indirect genetic mechanisms. Here, we present a method that bridges this gap, permitting high-throughput fluorescence-based measurements of in vitro steady-state transcription kinetics. We illustrate how an RNA-aptamer-based detection system can be used to generate quantitative information on direct mechanisms of transcriptional regulation and discuss the far-reaching implications for future applications.
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Affiliation(s)
- Drake Jensen
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
| | - Ana Ruiz Manzano
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
| | - Maxwell Rector
- Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - Eric J. Tomko
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
| | - M. Thomas Record
- Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - Eric A. Galburt
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
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21
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Cheng A, Wan D, Ghatak A, Wang C, Feng D, Fondell JD, Ebright RH, Fan H. Identification and Structural Modeling of the RNA Polymerase Omega Subunits in Chlamydiae and Other Obligate Intracellular Bacteria. mBio 2023; 14:e0349922. [PMID: 36719197 PMCID: PMC9973325 DOI: 10.1128/mbio.03499-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 01/04/2023] [Indexed: 02/01/2023] Open
Abstract
Gene transcription in bacteria is carried out by the multisubunit RNA polymerase (RNAP), which is composed of a catalytic core enzyme and a promoter-recognizing σ factor. The core enzyme comprises two α subunits, one β subunit, one β' subunit, and one ω subunit. The ω subunit plays critical roles in the assembly of the core enzyme and other cellular functions, including the regulation of bacterial growth, the stress response, and biofilm formation. However, the identity of an ω subunit for the obligate intracellular bacterium Chlamydia has not previously been determined. Here, we report the identification of the hypothetical protein CTL0286 as the probable chlamydial ω subunit based on sequence, synteny, and AlphaFold and AlphaFold-Multimer three-dimensional-structure predictions. Our findings indicate that CTL0286 functions as the missing ω subunit of chlamydial RNAP. Our extended analysis also indicates that all obligate intracellular bacteria have ω orthologs. IMPORTANCE Chlamydiae are obligate intracellular bacteria that replicate only inside eukaryotic cells. Previously, it has not been possible to identify a candidate gene encoding the chlamydial RNA polymerase ω subunit, and it has been hypothesized that the chlamydial RNA polymerase ω subunit was lost in the evolutionary process through which Chlamydiae reduced their genome size and proteome sizes to adapt to an obligate intracellular lifestyle. Here, we report the identification of the chlamydial RNA polymerase ω subunit, based on conserved sequence, conserved synteny, AlphaFold-predicted conserved three-dimensional structure, and AlfaFold-Multimer-predicted conserved interactions. Our identification of the previously elusive chlamydial RNA polymerase ω subunit sets the stage for investigation of its roles in regulation of gene expression during chlamydial growth, development, and stress responses, and sets the stage for preparation and study of the intact chlamydial RNA polymerase and its interactions with inhibitors.
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Affiliation(s)
- Andrew Cheng
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Danny Wan
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
- Graduate Program in Physiology and Integrative Biology, Rutgers School of Graduate Studies, Piscataway, New Jersey, USA
| | - Arkaprabha Ghatak
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Chengyuan Wang
- Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Deyu Feng
- Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Joseph D. Fondell
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Richard H. Ebright
- Waksman Institute, Rutgers University, Piscataway, New Jersey, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Huizhou Fan
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
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22
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de Campos LJ, Seleem MA, Feng J, Pires de Oliveira KM, de Andrade Dos Santos JV, Hayer S, Clayton JB, Kathi S, Fisher DJ, Ouellette SP, Conda-Sheridan M. Design, Biological Evaluation, and Computer-Aided Analysis of Dihydrothiazepines as Selective Antichlamydial Agents. J Med Chem 2023; 66:2116-2142. [PMID: 36696579 PMCID: PMC10056257 DOI: 10.1021/acs.jmedchem.2c01894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chlamydia trachomatis (CT) causes the most prevalent sexually transmitted bacterial disease in the United States. The lack of drug selectivity is one of the main challenges of the current antichlamydial pharmacotherapy. The metabolic needs of CT are controlled, among others, by cylindrical proteases and their chaperones (e.g., ClpX). It has been shown that dihydrothiazepines can disrupt CT-ClpXP. Based on this precedent, we synthesized a dihydrothiazepine library and characterized its antichlamydial activity using a modified semi-high-throughput screening assay. Then, we demonstrated their ability to inhibit ClpX ATPase activity in vitro, supporting ClpX as a target. Further, our lead compound displayed a promising selectivity profile against CT, acceptable cytotoxicity, no mutagenic potential, and good in vitro stability. A two-dimensional quantitative structure-activity relationship (2D QSAR) model was generated as a support tool in the identification of more potent antichlamydial molecules. This study suggests dihydrothiazepines are a promising starting point for the development of new and selective antichlamydial drugs.
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Affiliation(s)
- Luana Janaína de Campos
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Mohamed A Seleem
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Jiachen Feng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Kelly Mari Pires de Oliveira
- Faculty of Biological and Environmental Science, Federal University of Grande Dourados, Dourados, MS 79804-970, Brazil
| | | | - Shivdeep Hayer
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska 68182, United States
| | - Jonathan B Clayton
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska 68182, United States
- Department of Food Science and Technology, University of Nebraska─Lincoln, Lincoln, Nebraska 68588, United States
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Nebraska Food for Health Center, University of Nebraska─Lincoln, Lincoln, Nebraska 68508, United States
| | - Sharvath Kathi
- School of Biological Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Derek J Fisher
- School of Biological Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Scot P Ouellette
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Martin Conda-Sheridan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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23
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Aktories K. From signal transduction to protein toxins-a narrative review about milestones on the research route of C. difficile toxins. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:173-190. [PMID: 36203094 PMCID: PMC9831965 DOI: 10.1007/s00210-022-02300-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/22/2022] [Indexed: 01/29/2023]
Abstract
Selected findings about Clostridioides difficile (formerly Clostridium difficile) toxins are presented in a narrative review. Starting with a personal view on research about G proteins, adenylyl cyclase, and ADP-ribosylating toxins in the laboratory of Günter Schultz in Heidelberg, milestones of C. difficile toxin research are presented with the focus on toxin B (TcdB), covering toxin structure, receptor binding, toxin up-take and refolding, the intracellular actions of TcdB, and the treatment of C. difficile infection.
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Affiliation(s)
- Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Albertstr. 25, 79104, Freiburg, Germany.
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24
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Abstract
As the global burden of antibiotic resistance continues to grow, creative approaches to antibiotic discovery are needed to accelerate the development of novel medicines. A rapidly progressing computational revolution-artificial intelligence-offers an optimistic path forward due to its ability to alleviate bottlenecks in the antibiotic discovery pipeline. In this review, we discuss how advancements in artificial intelligence are reinvigorating the adoption of past antibiotic discovery models-namely natural product exploration and small molecule screening. We then explore the application of contemporary machine learning approaches to emerging areas of antibiotic discovery, including antibacterial systems biology, drug combination development, antimicrobial peptide discovery, and mechanism of action prediction. Lastly, we propose a call to action for open access of high-quality screening datasets and interdisciplinary collaboration to accelerate the rate at which machine learning models can be trained and new antibiotic drugs can be developed.
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Affiliation(s)
- Telmah Lluka
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, Ontario, Canada
| | - Jonathan M Stokes
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, Ontario, Canada
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25
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Caputo A, Sartini S, Levati E, Minato I, Elisi GM, Di Stasi A, Guillou C, Goekjian PG, Garcia P, Gueyrard D, Bach S, Comte A, Ottonello S, Rivara S, Montanini B. An Optimized Workflow for the Discovery of New Antimicrobial Compounds Targeting Bacterial RNA Polymerase Complex Formation. Antibiotics (Basel) 2022; 11:antibiotics11101449. [PMID: 36290107 PMCID: PMC9598883 DOI: 10.3390/antibiotics11101449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Bacterial resistance represents a major health problem worldwide and there is an urgent need to develop first-in-class compounds directed against new therapeutic targets. We previously developed a drug-discovery platform to identify new antimicrobials able to disrupt the protein–protein interaction between the β’ subunit and the σ70 initiation factor of bacterial RNA polymerase, which is essential for transcription. As a follow-up to such work, we have improved the discovery strategy to make it less time-consuming and more cost-effective. This involves three sequential assays, easily scalable to a high-throughput format, and a subsequent in-depth characterization only limited to hits that passed the three tests. This optimized workflow, applied to the screening of 5360 small molecules from three synthetic and natural compound libraries, led to the identification of six compounds interfering with the β’–σ70 interaction, and thus was capable of inhibiting promoter-specific RNA transcription and bacterial growth. Upon supplementation with a permeability adjuvant, the two most potent transcription-inhibiting compounds displayed a strong antibacterial activity against Escherichia coli with minimum inhibitory concentration (MIC) values among the lowest (0.87–1.56 μM) thus far reported for β’–σ PPI inhibitors. The newly identified hit compounds share structural feature similarities with those of a pharmacophore model previously developed from known inhibitors.
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Affiliation(s)
- Alessia Caputo
- Laboratory of Biochemistry and Molecular Biology, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
- Interdepartmental Research Centre Biopharmanet-Tec, University of Parma, 43124 Parma, Italy
| | - Sara Sartini
- Laboratory of Biochemistry and Molecular Biology, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA 90095, USA
| | - Elisabetta Levati
- Laboratory of Biochemistry and Molecular Biology, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Ilaria Minato
- Laboratory of Biochemistry and Molecular Biology, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
- Interdepartmental Research Centre Biopharmanet-Tec, University of Parma, 43124 Parma, Italy
| | - Gian Marco Elisi
- Department of Food and Drug, University of Parma, 43124 Parma, Italy
| | - Adriana Di Stasi
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Catherine Guillou
- Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Peter G. Goekjian
- Laboratoire Chimie Organique 2 Glycochimie, ICBMS UMR 5246 CNRS-Université Claude Bernard Lyon 1, Université de Lyon, 69622 Villeurbanne, France
| | - Pierre Garcia
- Laboratoire Chimie Organique 2 Glycochimie, ICBMS UMR 5246 CNRS-Université Claude Bernard Lyon 1, Université de Lyon, 69622 Villeurbanne, France
| | - David Gueyrard
- Laboratoire Chimie Organique 2 Glycochimie, ICBMS UMR 5246 CNRS-Université Claude Bernard Lyon 1, Université de Lyon, 69622 Villeurbanne, France
| | - Stéphane Bach
- Sorbonne Université, CNRS, UMR 8227, Integrative Biology of Marine Models, Team Physiology and Cell Fate, Station Biologique de Roscoff, CS 90074, 29680 Roscoff, France
- Sorbonne Université, CNRS, FR 2424, Plateforme de criblage KISSf (Kinase Inhibitor Specialized Screening Facility), Station Biologique de Roscoff, 29680 Roscoff, France
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
| | - Arnaud Comte
- Chimiothèque, ICBMS UMR 5246 CNRS-Université Claude Bernard Lyon 1, Université de Lyon, 69622 Villeurbanne, France
| | - Simone Ottonello
- Laboratory of Biochemistry and Molecular Biology, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
- Interdepartmental Research Centre Biopharmanet-Tec, University of Parma, 43124 Parma, Italy
| | - Silvia Rivara
- Interdepartmental Research Centre Biopharmanet-Tec, University of Parma, 43124 Parma, Italy
- Department of Food and Drug, University of Parma, 43124 Parma, Italy
| | - Barbara Montanini
- Laboratory of Biochemistry and Molecular Biology, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
- Interdepartmental Research Centre Biopharmanet-Tec, University of Parma, 43124 Parma, Italy
- Correspondence: ; Tel.: +39-0521-905654
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26
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Inamura K, Hamada T, Bullman S, Ugai T, Yachida S, Ogino S. Cancer as microenvironmental, systemic and environmental diseases: opportunity for transdisciplinary microbiomics science. Gut 2022; 71:gutjnl-2022-327209. [PMID: 35820782 PMCID: PMC9834441 DOI: 10.1136/gutjnl-2022-327209] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 06/28/2022] [Indexed: 02/06/2023]
Abstract
Cancer is generally regarded as a localised disease, with the well-established role of the tumour microenvironment. However, the realm of cancer goes beyond the tumour microenvironment, and cancer should also be regarded as a systemic and environmental disease. The exposome (ie, the totality of exposures), which encompasses diets, supplements, smoking, alcohol, other lifestyle factors, medications, etc, likely alters the microbiome (inclusive of bacteria, viruses, archaea, fungi, parasites, etc) and immune system in various body sites and influences tumour phenotypes. The systemic metabolic/inflammatory status, which is likely influenced by exposures and intestinal physiological changes, may affect tissue microenvironment of colorectum and any other organs. Germline genomic factors can modify disease phenotypes via gene-by-environment interactions. Although challenges exist, it is crucial to advance not only basic experimental research that can analyse the effects of exposures, microorganisms and microenvironmental components on tumour evolution but also interdisciplinary human population research that can dissect the complex pathogenic roles of the exposome, microbiome and immunome. Metagenomic, metatranscriptomic and metabolomic analyses should be integrated into well-designed population research combined with advanced methodologies of artificial intelligence and molecular pathological epidemiology. Ideally, a prospective cohort study design that enables biospecimen (such as stool) collection before disease detection should be considered to address reverse causation and recall biases. Robust experimental and observational research together can provide insights into dynamic interactions between environmental exposures, microbiota, tumour and immunity during carcinogenesis processes, thereby helping us develop precision prevention and therapeutic strategies to ultimately reduce the cancer burden.
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Affiliation(s)
- Kentaro Inamura
- Division of Pathology, The Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
- Department of Pathology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Tsuyoshi Hamada
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Hepato-Biliary-Pancreatic Medicine, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Susan Bullman
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Tomotaka Ugai
- Department of Epidemiology, Harvard University T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Program in MPE Molecular Pathological Epidemiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Shinichi Yachida
- Department of Cancer Genome Informatics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan
- Division of Genomic Medicine, National Cancer Center Research Institute, Tokyo, Japan
| | - Shuji Ogino
- Department of Epidemiology, Harvard University T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Program in MPE Molecular Pathological Epidemiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Cancer Immunology and Cancer Epidemiology Programs, Dana-Farber Harvard Cancer Center, Boston, Massachusetts, USA
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27
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Johnston CW, Badran AH. Natural and engineered precision antibiotics in the context of resistance. Curr Opin Chem Biol 2022; 69:102160. [PMID: 35660248 DOI: 10.1016/j.cbpa.2022.102160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/18/2022] [Accepted: 04/22/2022] [Indexed: 12/14/2022]
Abstract
Antibiotics are essential weapons in our fight against infectious disease, yet the consequences of broad-spectrum antibiotic use on microbiome stability and pathogen resistance are prompting investigations into more selective alternatives. Echoing the advent of precision medicine in oncology, precision antibiotics with focused activities are emerging as a means of addressing infections without damaging microbiomes or incentivizing resistance. Historically, antibiotic design principles have been gleaned from Nature, and reinvestigation of overlooked antibacterials is now providing scaffolds and targets for the design of pathogen-specific drugs. In this perspective, we summarize the biosynthetic and antibacterial mechanisms used to access these activities, and discuss how such strategies may be co-opted through engineering approaches to afford precision antibiotics.
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Affiliation(s)
- Chad W Johnston
- Department of Pharmacology & Chemical Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Ahmed H Badran
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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