1
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O'Connell LM, Coffey A, O'Mahony JM. Alternatives to antibiotics in veterinary medicine: considerations for the management of Johne's disease. Anim Health Res Rev 2023; 24:12-27. [PMID: 37475561 DOI: 10.1017/s146625232300004x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Antibiotic resistance has become a major health concern globally, with current predictions expecting deaths related to resistant infections to surpass those of cancer by 2050. Major efforts are being undertaken to develop derivative and novel alternatives to current antibiotic therapies in human medicine. What appears to be lacking however, are similar efforts into researching the application of those alternatives, such as (bacterio)phage therapy, in veterinary contexts. Agriculture is still undoubtedly the most prominent consumer of antibiotics, with up to 70% of annual antibiotic usage attributed to this sector, despite policies to reduce their use in food animals. This not only increases the risk of resistant infections spreading from farm to community but also the risk that animals may acquire species-specific infections that subvert treatment. While these diseases may not directly affect human welfare, they greatly affect the profit margin of industries reliant on livestock due to the cost of treatments and (more frequently) the losses associated with animal death. This means actively combatting animal infection not only benefits animal welfare but also global economies. In particular, targeting recurring or chronic conditions associated with certain livestock has the potential to greatly reduce financial losses. This can be achieved by developing novel diagnostics to quickly identify ill animals alongside the design of novel therapies. To explore this concept further, this review employs Johne's disease, a chronic gastroenteritis condition that affects ruminants, as a case study to exemplify the benefits of rapid diagnostics and effective treatment of chronic disease, with particular regard to the diagnostic and therapeutic potential of phage.
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Affiliation(s)
- Laura M O'Connell
- Department of Biological Sciences, Munster Technological University, Rossa Avenue, Bishopstown, Cork, T12 P928, Ireland
| | - Aidan Coffey
- Department of Biological Sciences, Munster Technological University, Rossa Avenue, Bishopstown, Cork, T12 P928, Ireland
| | - Jim M O'Mahony
- Department of Biological Sciences, Munster Technological University, Rossa Avenue, Bishopstown, Cork, T12 P928, Ireland
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2
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Ayon NJ. High-Throughput Screening of Natural Product and Synthetic Molecule Libraries for Antibacterial Drug Discovery. Metabolites 2023; 13:625. [PMID: 37233666 PMCID: PMC10220967 DOI: 10.3390/metabo13050625] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/29/2023] [Accepted: 05/01/2023] [Indexed: 05/27/2023] Open
Abstract
Due to the continued emergence of resistance and a lack of new and promising antibiotics, bacterial infection has become a major public threat. High-throughput screening (HTS) allows rapid screening of a large collection of molecules for bioactivity testing and holds promise in antibacterial drug discovery. More than 50% of the antibiotics that are currently available on the market are derived from natural products. However, with the easily discoverable antibiotics being found, finding new antibiotics from natural sources has seen limited success. Finding new natural sources for antibacterial activity testing has also proven to be challenging. In addition to exploring new sources of natural products and synthetic biology, omics technology helped to study the biosynthetic machinery of existing natural sources enabling the construction of unnatural synthesizers of bioactive molecules and the identification of molecular targets of antibacterial agents. On the other hand, newer and smarter strategies have been continuously pursued to screen synthetic molecule libraries for new antibiotics and new druggable targets. Biomimetic conditions are explored to mimic the real infection model to better study the ligand-target interaction to enable the designing of more effective antibacterial drugs. This narrative review describes various traditional and contemporaneous approaches of high-throughput screening of natural products and synthetic molecule libraries for antibacterial drug discovery. It further discusses critical factors for HTS assay design, makes a general recommendation, and discusses possible alternatives to traditional HTS of natural products and synthetic molecule libraries for antibacterial drug discovery.
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Affiliation(s)
- Navid J Ayon
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
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3
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Yeware A, Akhtar S, Sarkar D. Probes and techniques used in active and the hypoxia-based dormant state of an antitubercular drug screening assay. MEDICINE IN DRUG DISCOVERY 2022. [DOI: 10.1016/j.medidd.2021.100115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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4
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A Unique Dual-Readout High-Throughput Screening Assay To Identify Antifungal Compounds with Aspergillus fumigatus. mSphere 2021; 6:e0053921. [PMID: 34406854 PMCID: PMC8386399 DOI: 10.1128/msphere.00539-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Treatment of invasive mold infections is limited by the lack of adequate drug options that are effective against these fatal infections. High-throughput screening of molds using traditional antifungal assays of growth is problematic and has greatly limited our ability to identify new mold-active agents. Here, we present a high-throughput screening platform for use with Aspergillus fumigatus, the most common causative agent of invasive mold infections, for the discovery of novel mold-active antifungals. This assay detects cell lysis through the release of the cytosolic enzyme adenylate kinase and, thus, is not dependent on changes in biomass or metabolism to detect antifungal activity. The ability to specifically detect cell lysis is a unique aspect of this assay that allows identification of molecules that disrupt fungal cell integrity, such as cell wall-active molecules. We also found that germinating A. fumigatus conidia release low levels of adenylate kinase and that a reduction in this background allowed us to identify molecules that inhibit conidial germination, expanding the potential for discovery of novel antifungal compounds. Here, we describe the validation of this assay and proof-of-concept pilot screens that identified a novel antifungal compound, PIK-75, that disrupts cell wall integrity. This screening assay provides a novel platform for high-throughput screens with A. fumigatus for the identification of anti-mold drugs. IMPORTANCE Fungal infections caused by molds have the highest mortality rates of human fungal infections. These devastating infections are hard to treat and available antifungal drugs are often not effective. Therefore, the identification of new antifungal drugs with mold activity is critical. Drug screening with molds is challenging and there are limited assays available to identify new antifungal compounds directly with these organisms. Here, we present an assay suitable for use for high-throughput screening with a common mold pathogen. This assay has exciting future potential for the identification of new drugs to treat these fatal infections.
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5
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Patil V, Noonikara-Poyil A, Joshi SD, Patil SA, Patil SA, Lewis AM, Bugarin A. Synthesis, molecular docking studies, and in vitro evaluation of 1,3,5-triazine derivatives as promising antimicrobial agents. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128687] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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6
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Elnaas AR, Grice D, Han J, Feng Y, Capua AD, Mak T, Laureanti JA, Buchko GW, Myler PJ, Cook G, Quinn RJ, Liu M. Discovery of a Natural Product That Binds to the Mycobacterium tuberculosis Protein Rv1466 Using Native Mass Spectrometry. Molecules 2020; 25:molecules25102384. [PMID: 32455540 PMCID: PMC7288112 DOI: 10.3390/molecules25102384] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 12/18/2022] Open
Abstract
Elucidation of the mechanism of action of compounds with cellular bioactivity is important for progressing compounds into future drug development. In recent years, phenotype-based drug discovery has become the dominant approach to drug discovery over target-based drug discovery, which relies on the knowledge of a specific drug target of a disease. Still, when targeting an infectious disease via a high throughput phenotypic assay it is highly advantageous to identifying the compound’s cellular activity. A fraction derived from the plant Polyalthia sp. showed activity against Mycobacterium tuberculosis at 62.5 μge/μL. A known compound, altholactone, was identified from this fraction that showed activity towards M. tuberculosis at an minimum inhibitory concentration (MIC) of 64 μM. Retrospective analysis of a target-based screen against a TB proteome panel using native mass spectrometry established that the active fraction was bound to the mycobacterial protein Rv1466 with an estimated pseudo-Kd of 42.0 ± 6.1 µM. Our findings established Rv1466 as the potential molecular target of altholactone, which is responsible for the observed in vivo toxicity towards M. tuberculosis.
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Affiliation(s)
- Ali R. Elnaas
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia; (A.R.E.); (J.H.); (Y.F.); (A.D.C.); (T.M.); (R.J.Q.)
| | - Darren Grice
- Institute for Glycomics, Griffith University, Gold Coast, Queensland 4222, Australia;
| | - Jianying Han
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia; (A.R.E.); (J.H.); (Y.F.); (A.D.C.); (T.M.); (R.J.Q.)
| | - Yunjiang Feng
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia; (A.R.E.); (J.H.); (Y.F.); (A.D.C.); (T.M.); (R.J.Q.)
| | - Angela Di Capua
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia; (A.R.E.); (J.H.); (Y.F.); (A.D.C.); (T.M.); (R.J.Q.)
| | - Tin Mak
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia; (A.R.E.); (J.H.); (Y.F.); (A.D.C.); (T.M.); (R.J.Q.)
| | - Joseph A. Laureanti
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA;
| | - Garry W. Buchko
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA;
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA
| | - Peter J. Myler
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA 98109, USA;
| | - Gregory Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand;
| | - Ronald J. Quinn
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia; (A.R.E.); (J.H.); (Y.F.); (A.D.C.); (T.M.); (R.J.Q.)
| | - Miaomiao Liu
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia; (A.R.E.); (J.H.); (Y.F.); (A.D.C.); (T.M.); (R.J.Q.)
- Correspondence: ; Tel.: +61-7-3735-6077
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7
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Design, synthesis, and molecular docking study of new piperazine derivative as potential antimicrobial agents. Bioorg Chem 2019; 92:103217. [DOI: 10.1016/j.bioorg.2019.103217] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/19/2019] [Accepted: 08/22/2019] [Indexed: 11/17/2022]
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8
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Patil M, Noonikara-Poyil A, Joshi SD, Patil SA, Patil SA, Bugarin A. New Urea Derivatives as Potential Antimicrobial Agents: Synthesis, Biological Evaluation, and Molecular Docking Studies. Antibiotics (Basel) 2019; 8:antibiotics8040178. [PMID: 31600950 PMCID: PMC6963781 DOI: 10.3390/antibiotics8040178] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/01/2019] [Accepted: 10/05/2019] [Indexed: 12/29/2022] Open
Abstract
A series of new urea derivatives, containing aryl moieties as potential antimicrobial agents, were designed, synthesized, and characterized by 1H NMR, 13C NMR, FT-IR, and LCMS spectral techniques. All newly synthesized compounds were screened in vitro against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). Variable levels of interaction were observed for these urea derivatives. However, and of major importance, many of these molecules exhibited promising growth inhibition against Acinetobacter baumannii. In particular, to our delight, the adamantyl urea adduct 3l demonstrated outstanding growth inhibition (94.5%) towards Acinetobacter baumannii. In light of this discovery, molecular docking studies were performed in order to elucidate the binding interaction mechanisms of the most active compounds, as reported herein.
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Affiliation(s)
- Mahadev Patil
- Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Bangalore 562112, Karnataka, India.
| | - Anurag Noonikara-Poyil
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019, USA.
| | - Shrinivas D Joshi
- Department of Pharmaceutical Chemistry, S. E. T's College of Pharmacy, Sangolli Rayanna Nagar, Dharwad 580 002, Karnataka, India.
| | - Shivaputra A Patil
- Pharmaceutical Sciences Department, College of Pharmacy, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Siddappa A Patil
- Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Bangalore 562112, Karnataka, India.
| | - Alejandro Bugarin
- Department of Chemistry and Physics, Florida Gulf Coast University, Fort Myers, FL 33965, USA.
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9
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Patil M, Poyil AN, Joshi SD, Patil SA, Patil SA, Bugarin A. Synthesis, molecular docking studies, and antimicrobial evaluation of new structurally diverse ureas. Bioorg Chem 2019; 87:302-311. [DOI: 10.1016/j.bioorg.2019.03.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/09/2019] [Accepted: 03/12/2019] [Indexed: 10/27/2022]
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10
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Nguyen TV, Minrovic BM, Melander RJ, Melander C. Identification of Anti-Mycobacterial Biofilm Agents Based on the 2-Aminoimidazole Scaffold. ChemMedChem 2019; 14:927-937. [PMID: 30834698 DOI: 10.1002/cmdc.201900033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 03/04/2019] [Indexed: 12/12/2022]
Abstract
Tuberculosis (TB) remains a significant global health problem for which new therapeutic options are sorely needed. The ability of the causative agent, Mycobacterium tuberculosis, to reside within host macrophages and form biofilm-like communities contributes to the persistent and drug-tolerant nature of the disease. Compounds that can prevent or reverse the biofilm-like phenotype have the potential to serve alongside TB antibiotics to overcome this tolerance, and decrease treatment duration. Using Mycobacterium smegmatis as a surrogate organism, we report the identification of two new 2-aminoimidazole compounds that inhibit and disperse mycobacterial biofilms, work synergistically with isoniazid and rifampicin to eradicate preformed M. smegmatis biofilms in vitro, are nontoxic toward Galleria mellonella, and exhibit stability in mouse plasma.
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Affiliation(s)
- T Vu Nguyen
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Bradley M Minrovic
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Roberta J Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
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11
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Nguyen TV, Peszko MT, Melander RJ, Melander C. Using 2-aminobenzimidazole derivatives to inhibit Mycobacterium smegmatis biofilm formation. MEDCHEMCOMM 2019; 10:456-459. [PMID: 31015909 PMCID: PMC6457209 DOI: 10.1039/c9md00025a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 02/07/2019] [Indexed: 12/18/2022]
Abstract
Biofilm formation by mycobacteria can lead to enhanced antibiotic tolerance. Herein, we report on the identification of a series of 2-aminobenzimidazole (2-ABI) derivatives that potently inhibit biofilm formation by Mycobacterium smegmatis.
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Affiliation(s)
- T Vu Nguyen
- Department of Chemistry , North Carolina State University , Raleigh , NC 27695 , USA
| | - Matthew T Peszko
- Department of Chemistry , North Carolina State University , Raleigh , NC 27695 , USA
| | - Roberta J Melander
- Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , IN 46556 , USA .
| | - Christian Melander
- Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , IN 46556 , USA .
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12
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Arthur PK, Amarh V, Cramer P, Arkaifie GB, Blessie EJS, Fuseini MS, Carilo I, Yeboah R, Asare L, Robertson BD. Characterization of Two New Multidrug-Resistant Strains of Mycobacterium smegmatis: Tools for Routine In Vitro Screening of Novel Anti-Mycobacterial Agents. Antibiotics (Basel) 2019; 8:antibiotics8010004. [PMID: 30609766 PMCID: PMC6466533 DOI: 10.3390/antibiotics8010004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/07/2018] [Accepted: 12/07/2018] [Indexed: 11/25/2022] Open
Abstract
Mycobacterium tuberculosis is a pathogen of global public health concern. This threat is exacerbated by the emergence of multidrug-resistant and extremely-drug-resistant strains of the pathogen. We have obtained two distinct clones of multidrug-resistant Mycobacterium smegmatis after gradual exposure of Mycobacterium smegmatis mc2 155 to increasing concentrations of erythromycin. The resulting resistant strains of Mycobacterium smegmatis exhibited robust viability in the presence of high concentrations of erythromycin and were found to be resistant to a wide range of other antimicrobials. They also displayed a unique growth phenotype in comparison to the parental drug-susceptible Mycobacterium smegmatis mc2 155, and a distinct colony morphology in the presence of cholesterol. We propose that these two multidrug-resistant clones of Mycobacterium smegmatis could be used as model organisms at the inceptive phase of routine in vitro screening of novel antimicrobial agents targeted against multidrug-resistant Mycobacterial tuberculosis.
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Affiliation(s)
- Patrick K Arthur
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Vincent Amarh
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Precious Cramer
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Gloria B Arkaifie
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Ethel J S Blessie
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Mohammed-Sherrif Fuseini
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Isaac Carilo
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Rebecca Yeboah
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Leonard Asare
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, P. O. Box LG 54, Accra, Ghana.
| | - Brian D Robertson
- Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, UK.
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13
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A Drug Repositioning Approach Reveals that Streptococcus mutans Is Susceptible to a Diverse Range of Established Antimicrobials and Nonantibiotics. Antimicrob Agents Chemother 2017; 62:AAC.01674-17. [PMID: 29061736 DOI: 10.1128/aac.01674-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/07/2017] [Indexed: 02/06/2023] Open
Abstract
Streptococcus mutans is the primary causative agent of dental caries and contributes to the multispecies biofilm known as dental plaque. An adenylate kinase-based assay was optimized for S. mutans to detect cell lysis when exposed to the Selleck library (Selleck Chemical, Houston, TX) of 853 FDA-approved drugs in, to our knowledge, the first high-throughput drug screen in S. mutans We found 126 drugs with activity against S. mutans planktonic cultures, and they were classified into six categories: antibacterials (61), antineoplastics (23), ion channel effectors (9), other antimicrobials (7), antifungals (6), and other (20). These drugs were also tested for activity against S. mutans biofilm cultures, and 24 compounds were found to inhibit biofilm formation, 6 killed preexisting biofilms, 84 exhibited biofilm inhibition and killing activity, and 12 had no activity against biofilms. The activities of 9 selected compounds that exhibited antimicrobial activity were further characterized for their activity against S. mutans planktonic and biofilm cultures. Together, our results suggest that S. mutans exhibits a susceptibility profile to a diverse array of established and novel antibacterials.
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14
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Dalton JP, Uy B, Okuda KS, Hall CJ, Denny WA, Crosier PS, Swift S, Wiles S. Screening of anti-mycobacterial compounds in a naturally infected zebrafish larvae model. J Antimicrob Chemother 2016; 72:421-427. [PMID: 27798206 DOI: 10.1093/jac/dkw421] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 08/28/2016] [Accepted: 09/07/2016] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Mycobacterium tuberculosis is a deadly human pathogen that causes the lung disease TB. M. tuberculosis latently infects a third of the world's population, resulting in ∼1.5 million deaths per year. Due to the difficulties and expense of carrying out animal drug trials using M. tuberculosis and rodents, infections of the zebrafish Danio rerio with Mycobacterium marinum have become a useful surrogate. However, the infection methods described to date require specialized equipment and a high level of operator expertise. METHODS We investigated whether zebrafish larvae could be naturally infected with bioluminescently labelled M. marinum by immersion, and whether infected larvae could be used for rapid screening of anti-mycobacterial compounds using bioluminescence. We used rifampicin and a variety of nitroimidazole-based next-generation and experimental anti-mycobacterial drugs, selected for their wide range of potencies against M. tuberculosis, to validate this model for anti-mycobacterial drug discovery. RESULTS We observed that five of the six treatments (rifampicin, pretomanid, delamanid, SN30488 and SN30527) significantly reduced the bioluminescent signal from M. marinum within naturally infected zebrafish larvae. Importantly, these same five treatments also retarded the growth of M. tuberculosis in vitro. In contrast, only three of the six treatments tested (rifampicin, delamanid and SN30527) retarded the growth of M. marinum in vitro. CONCLUSIONS We have demonstrated that zebrafish larvae naturally infected with bioluminescent M. marinum M can be used for the rapid screening of anti-mycobacterial compounds with readily available equipment and limited expertise. The result is an assay that can be carried out by a wide variety of laboratories for minimal cost and without high levels of zebrafish expertise.
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Affiliation(s)
- J P Dalton
- Bioluminescent Superbugs Lab, University of Auckland, Auckland, New Zealand.,Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - B Uy
- Bioluminescent Superbugs Lab, University of Auckland, Auckland, New Zealand.,Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - K S Okuda
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - C J Hall
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - W A Denny
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.,Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - P S Crosier
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - S Swift
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - S Wiles
- Bioluminescent Superbugs Lab, University of Auckland, Auckland, New Zealand .,Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
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15
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Kaur P, Datta S, Shandil RK, Kumar N, Robert N, Sokhi UK, Guptha S, Narayanan S, Anbarasu A, Ramaiah S. Unravelling the Secrets of Mycobacterial Cidality through the Lens of Antisense. PLoS One 2016; 11:e0154513. [PMID: 27144597 PMCID: PMC4856384 DOI: 10.1371/journal.pone.0154513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/14/2016] [Indexed: 01/13/2023] Open
Abstract
One of the major impediments in anti-tubercular drug discovery is the lack of a robust grammar that governs the in-vitro to the in-vivo translation of efficacy. Mycobacterium tuberculosis (Mtb) is capable of growing both extracellular as well as intracellular; encountering various hostile conditions like acidic milieu, free radicals, starvation, oxygen deprivation, and immune effector mechanisms. Unique survival strategies of Mtb have prompted researchers to develop in-vitro equivalents to simulate in-vivo physiologies and exploited to find efficacious inhibitors against various phenotypes. Conventionally, the inhibitors are screened on Mtb under the conditions that are unrelated to the in-vivo disease environments. The present study was aimed to (1). Investigate cidality of Mtb targets using a non-chemical inhibitor antisense-RNA (AS-RNA) under in-vivo simulated in-vitro conditions.(2). Confirm the cidality of the targets under in-vivo in experimental tuberculosis. (3). Correlate in-vitro vs. in-vivo cidality data to identify the in-vitro condition that best predicts in-vivo cidality potential of the targets. Using cidality as a metric for efficacy, and AS-RNA as a target-specific inhibitor, we delineated the cidality potential of five target genes under six different physiological conditions (replicating, hypoxia, low pH, nutrient starvation, nitrogen depletion, and nitric oxide).In-vitro cidality confirmed in experimental tuberculosis in BALB/c mice using the AS-RNA allowed us to identify cidal targets in the rank order of rpoB>aroK>ppk>rpoC>ilvB. RpoB was used as the cidality control. In-vitro and in-vivo studies feature aroK (encoding shikimate kinase) as an in-vivo mycobactericidal target suitable for anti-TB drug discovery. In-vitro to in-vivo cidality correlations suggested the low pH (R = 0.9856) in-vitro model as best predictor of in-vivo cidality; however, similar correlation studies in pathologically relevant (Kramnik) mice are warranted. In the acute infection phase for the high fidelity translation, the compound efficacy may also be evaluated in the low pH, in addition to the standard replication condition.
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Affiliation(s)
- Parvinder Kaur
- Research Area, Drug Discovery, AstraZeneca India Private Limited, Bangalore, India
- * E-mail:
| | | | | | - Naveen Kumar
- Research Area, Drug Discovery, AstraZeneca India Private Limited, Bangalore, India
| | - Nanduri Robert
- Research Area, Drug Discovery, AstraZeneca India Private Limited, Bangalore, India
| | - Upneet K. Sokhi
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, New York, New York, United States of America
| | - Supreeth Guptha
- Research Area, Drug Discovery, AstraZeneca India Private Limited, Bangalore, India
| | - Shridhar Narayanan
- Research Area, Drug Discovery, AstraZeneca India Private Limited, Bangalore, India
| | - Anand Anbarasu
- School of Biosciences and Technology, VIT University, Vellore, India
| | - Sudha Ramaiah
- School of Biosciences and Technology, VIT University, Vellore, India
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Identification of New Molecular Entities (NMEs) as Potential Leads against Tuberculosis from Open Source Compound Repository. PLoS One 2015; 10:e0144018. [PMID: 26642200 PMCID: PMC4671662 DOI: 10.1371/journal.pone.0144018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/12/2015] [Indexed: 02/04/2023] Open
Abstract
The purpose of this study was to provide a number of diverse and promising early-lead compounds that will feed into the drug discovery pipeline for developing new antitubercular agents. The results from the phenotypic screening of the open-source compound library against Mycobacterium smegmatis and Mycobacterium bovis (BCG) with hit validation against M. tuberculosis (H37Rv) have identified novel potent hit compounds. To determine their druglikeness, a systematic analysis of physicochemical properties of the hit compounds has been performed using cheminformatics tools. The hit molecules were analysed by clustering based on their chemical finger prints and structural similarity determining their chemical diversity. The hit compound library is also filtered for druglikeness based on the physicochemical descriptors following Lipinski filters. The robust filtration of hits followed by secondary screening against BCG, H37Rv and cytotoxicity evaluation has identified 12 compounds with potential against H37Rv (MIC range 0.4 to 12.5 μM). Furthermore in cytotoxicity assays, 12 compounds displayed low cytotoxicity against liver and lung cells providing high therapeutic index > 50. To avoid any variations in activity due to the route of chemical synthesis, the hit compounds were re synthesized independently and confirmed for their potential against H37Rv. Taken together, the hits reported here provides copious potential starting points for generation of new leads eventually adds to drug discovery pipeline against tuberculosis.
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