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Zhao X, Verma R, Sridhara MB, Sharath Kumar KS. Fluorinated azoles as effective weapons in fight against methicillin-resistance staphylococcus aureus (MRSA) and its SAR studies. Bioorg Chem 2024; 143:106975. [PMID: 37992426 DOI: 10.1016/j.bioorg.2023.106975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/22/2023] [Accepted: 11/14/2023] [Indexed: 11/24/2023]
Abstract
The rapid spread of Methicillin-resistant Staphylococcus aureus (MRSA) and its difficult-to-treat skin and filmsy diseases are making MRSA a threat to human life. The most dangerous feature is the fast emergence of MRSA resistance to all recognized antibiotics, including vancomycin. The creation of novel, effective, and non-toxic drug candidates to combat MRSA isolates is urgently required. Fluorine containing small molecules have taken a centre stage in the field of drug development. Over the last 50 years, there have been a growing number of fluorinated compounds that have been approved since the clinical usage of fluorinated corticosteroids in the 1950 s and fluoroquinolones in the 1980 s. Due to its advantages in terms of potency and ADME (absorption, distribution, metabolism, and excretion), fluoro-pharmaceuticals have been regarded as a potent and useful tool in the rational drug design method. The flexible bioactive fluorinated azoles are ideal candidates for the development of new antibiotics. This review summarizes the decade developments of fluorinated azole derivatives with a wide antibacterial activity against diverged MRSA strains. In specific, we correlated the efficacy of structurally varied fluorinated azole analogues including thiazole, benzimidazole, oxadiazole and pyrazole against MRSA and discussed different angles of structure-activity relationship (SAR).
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Affiliation(s)
- Xuanming Zhao
- Energy Engineering College, Yulin University, Yulin City-719000, P. R. China
| | - Rameshwari Verma
- School of New Energy, Yulin University, Yulin 719000, Shaanxi, P. R. China
| | - M B Sridhara
- Department of Chemistry, Rani Channamma University, Vidyasangama, Belagavi 591156, India
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Barbachyn MR. Identification of a 1,2,4-Oxadiazole with Potent and Specific Activity against Clostridioides difficile, the Causative Bacterium of C. difficile Infection, an Urgent Public Health Threat. J Med Chem 2023; 66:13888-13890. [PMID: 37823241 PMCID: PMC10614189 DOI: 10.1021/acs.jmedchem.3c01778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Indexed: 10/13/2023]
Abstract
The discovery of compound 57, a new, totally synthetic 1,2,4-oxadiazole antibacterial agent, is described. This oxadiazole displays highly selective, bactericidal killing of Clostridioides (Clostridium) difficile, the bacterium that causes C. difficile infection (CDI) in both hospital and community settings. The narrow spectrum of activity exhibited by 57 should avoid any disruption of commensal anaerobic bacteria in the gut microbiome, minimizing chances for recurrent CDI.
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Qian Y, Birhanu BT, Yang J, Ding D, Janardhanan J, Mobashery S, Chang M. A Potent and Narrow-Spectrum Antibacterial against Clostridioides difficile Infection. J Med Chem 2023; 66:13891-13899. [PMID: 37732641 DOI: 10.1021/acs.jmedchem.3c01249] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Clostridioides difficile is an anaerobic Gram-positive bacterium that colonizes the gut of patients treated with broad-spectrum antibiotics. The normal gut microflora prevents C. difficile colonization; however, dysbiosis by treatment with broad-spectrum antibiotics causes recurrent C. difficile infection (CDI) in 25% of patients. There are no fully effective antibiotics for multiple recurrent CDIs. We report herein that oxadiazole antibiotics exhibit bactericidal activity against C. difficile vegetative cells. We screened a library of 75 oxadiazoles against C. difficile ATCC 43255. The findings from this collection served as the basis for the syntheses of an additional 58 analogs, which were tested against the same strain. We report a potent (MIC50 = 0.5 μg/mL and MIC90 = 1 μg/mL values for 101 C. difficile strains) and narrow-spectrum oxadiazole (3-(4-(cyclopentyloxy)phenyl)-5-(4-nitro-1H-imidazol-2-yl)-1,2,4-oxadiazole; compound 57), which is not active against common gut bacteria or other tested organisms. Compound 57 is selectively bactericidal against C. difficile and targets cell-wall synthesis.
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Affiliation(s)
- Yuanyuan Qian
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Biruk T Birhanu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jingdong Yang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Derong Ding
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jeshina Janardhanan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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4
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Dai J, Battini N, Zang Z, Luo Y, Zhou C. Novel Thiazolylketenyl Quinazolinones as Potential Anti-MRSA Agents and Allosteric Modulator for PBP2a. Molecules 2023; 28:molecules28104240. [PMID: 37241983 DOI: 10.3390/molecules28104240] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
Bacterial infections caused by methicillin-resistant Staphylococcus aureus have seriously threatened public health. There is an urgent need to propose an existing regimen to overcome multidrug resistance of MRSA. A unique class of novel anti-MRSA thiazolylketenyl quinazolinones (TQs) and their analogs were developed. Some synthesized compounds showed good bacteriostatic potency. Especially TQ 4 was found to exhibit excellent inhibition against MRSA with a low MIC of 0.5 μg/mL, which was 8-fold more effective than norfloxacin. The combination of TQ 4 with cefdinir showed stronger antibacterial potency. Further investigation revealed that TQ 4, with low hemolytic toxicity and low drug resistance, was not only able to inhibit biofilm formation but also could reduce MRSA metabolic activity and showed good drug-likeness. Mechanistic explorations revealed that TQ 4 could cause leakage of proteins by disrupting membrane integrity and block DNA replication by intercalated DNA. Furthermore, the synergistic antibacterial effect with cefdinir might be attributed to TQ 4 with the ability to induce PBP2a allosteric regulation of MRSA and further trigger the opening of the active site to promote the binding of cefdinir to the active site, thus inhibiting the expression of PBP2a, thereby overcoming MRSA resistance and significantly enhancing the anti-MRSA activity of cefdinir. A new strategy provided by these findings was that TQ 4, possessing both excellent anti-MRSA activity and allosteric effect of PBP2a, merited further development as a novel class of antibacterial agents to overcome increasingly severe MRSA infections.
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Affiliation(s)
- Jie Dai
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Narsaiah Battini
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Zhonglin Zang
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Yan Luo
- College of Pharmacy, National & Local Joint Engineering Research Center of Targeted and Innovative Therapeutics, Chongqing Key Laboratory of Kinase Modulators as Innovative Medicine, Chongqing University of Arts and Sciences, Chongqing 402160, China
| | - Chenghe Zhou
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
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5
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Dhanda G, Acharya Y, Haldar J. Antibiotic Adjuvants: A Versatile Approach to Combat Antibiotic Resistance. ACS OMEGA 2023; 8:10757-10783. [PMID: 37008128 PMCID: PMC10061514 DOI: 10.1021/acsomega.3c00312] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/21/2023] [Indexed: 06/13/2023]
Abstract
The problem of antibiotic resistance is on the rise, with multidrug-resistant strains emerging even to the last resort antibiotics. The drug discovery process is often stalled by stringent cut-offs required for effective drug design. In such a scenario, it is prudent to delve into the varying mechanisms of resistance to existing antibiotics and target them to improve antibiotic efficacy. Nonantibiotic compounds called antibiotic adjuvants which target bacterial resistance can be used in combination with obsolete drugs for an improved therapeutic regime. The field of "antibiotic adjuvants" has gained significant traction in recent years where mechanisms other than β-lactamase inhibition have been explored. This review discusses the multitude of acquired and inherent resistance mechanisms employed by bacteria to resist antibiotic action. The major focus of this review is how to target these resistance mechanisms by the use of antibiotic adjuvants. Different types of direct acting and indirect resistance breakers are discussed including enzyme inhibitors, efflux pump inhibitors, inhibitors of teichoic acid synthesis, and other cellular processes. The multifaceted class of membrane-targeting compounds with poly pharmacological effects and the potential of host immune-modulating compounds have also been reviewed. We conclude with providing insights about the existing challenges preventing clinical translation of different classes of adjuvants, especially membrane-perturbing compounds, and a framework about the possible directions which can be pursued to fill this gap. Antibiotic-adjuvant combinatorial therapy indeed has immense potential to be used as an upcoming orthogonal strategy to conventional antibiotic discovery.
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Affiliation(s)
- Geetika Dhanda
- Antimicrobial
Research Laboratory, New Chemistry Unit and School of Advanced
Materials, Jawaharlal Nehru Centre for Advanced
Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India
| | - Yash Acharya
- Antimicrobial
Research Laboratory, New Chemistry Unit and School of Advanced
Materials, Jawaharlal Nehru Centre for Advanced
Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India
| | - Jayanta Haldar
- Antimicrobial
Research Laboratory, New Chemistry Unit and School of Advanced
Materials, Jawaharlal Nehru Centre for Advanced
Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India
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Zhang PL, Gopala L, Zhang SL, Cai GX, Zhou CH. An unanticipated discovery towards novel naphthalimide corbelled aminothiazoximes as potential anti-MRSA agents and allosteric modulators for PBP2a. Eur J Med Chem 2021; 229:114050. [PMID: 34922190 DOI: 10.1016/j.ejmech.2021.114050] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/26/2021] [Accepted: 12/09/2021] [Indexed: 12/14/2022]
Abstract
Available therapeutic strategies are urgently needed to conquer multidrug resistance of MRSA. A visible effort was guided towards the advancement of novel antibacterial framework of naphthalimide corbelled aminothiazoximes, and desired to assert some insight on the conjunction of individual pharmacophore with distinct biological activities and unique action mechanism. Preliminary assessment displayed that dimethylenediamine derivative 13d presented a wonderful inhibition on MRSA (MIC = 0.5 μg/mL), and showed excellent membrane selectivity (HC50 > 200 μg/mL) from an electrostatic distinction of the electronegative bacterial membranes and the electroneutral mammalian membranes. Moreover, 13d could effectually relieve the development of MRSA resistance. Investigations into explaining the mechanism of anti-MRSA disclosed that 13d displayed strong lipase affinity, which facilitated its permeation into cell membrane, causing membrane depolarization, leakage of cytoplasmic contents and lactate dehydrogenase (LDH) inhibition. Meanwhile, 13d could exert interaction with DNA to hinder biological function of DNA, and disrupt the antioxidant defense system of MRSA through up-regulation of ROS subjected the strain to oxidative stress. In particular, the unanticipated mechanism for naphthalimide corbelled aminothiazoximes that 13d could suppress the expression of PBP2a by inducing allosteric modulation of PBP2a and triggering the open of the active site, was discovered for the first time. These findings of naphthalimide corbelled aminothiazoximes as a small-molecule class of anti-MRSA agents held promise in strategies for treatment of MRSA infections.
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Affiliation(s)
- Peng-Li Zhang
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China
| | - Lavanya Gopala
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China
| | - Shao-Lin Zhang
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing, 401331, China.
| | - Gui-Xin Cai
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
| | - Cheng-He Zhou
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
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7
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Shakour N, Hadizadeh F, Kesharwani P, Sahebkar A. 3D-QSAR Studies of 1,2,4-Oxadiazole Derivatives as Sortase A Inhibitors. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6380336. [PMID: 34912894 PMCID: PMC8668286 DOI: 10.1155/2021/6380336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/23/2021] [Accepted: 11/13/2021] [Indexed: 12/20/2022]
Abstract
Sortase A (SrtA) is an enzyme that catalyzes the attachment of proteins to the cell wall of Gram-positive bacterial membrane, preventing the spread of pathogenic bacterial strains. Here, one class of oxadiazole compounds was distinguished as an efficient inhibitor of SrtA via the "S. aureus Sortase A" substrate-based virtual screening. The current study on 3D-QSAR was done by utilizing preparation of the structure in the Schrödinger software suite and an assessment of 120 derivatives with the crystal structure of 1,2,4-oxadiazole which was extracted from the PDB data bank. The docking operation of the best compound in terms of pMIC (pMIC = 2.77) was done to determine the drug likeliness and binding form of 1,2,4-oxadiazole derivatives as antibiotics in the active site. Using the kNN-MFA way, seven models of 3D-QSAR were created and amongst them, and one model was selected as the best. The chosen model based on q 2 (pred_r 2) and R 2 values related to the sixth factor of PLS illustrates better and more acceptable external and internal predictions. Values of crossvalidation (pred_r 2), validation (q 2), and F were observed 0.5479, 0.6319, and 179.0, respectively, for a test group including 24 molecules and the training group including 96 molecules. The external reliability outcomes showed that the acceptable and the selective 3D-QSAR model had a high predictive potential (R 2 = 0.9235) which was confirmed by the Y-randomization test. Besides, the model applicability domain was described successfully to validate the estimation of the model.
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Affiliation(s)
- Neda Shakour
- Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
- Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Farzin Hadizadeh
- Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Prashant Kesharwani
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
- Department of Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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8
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Verma SK, Verma R, Kumar KSS, Banjare L, Shaik AB, Bhandare RR, Rakesh KP, Rangappa KS. A key review on oxadiazole analogs as potential methicillin-resistant Staphylococcus aureus (MRSA) activity: Structure-activity relationship studies. Eur J Med Chem 2021; 219:113442. [PMID: 33878562 DOI: 10.1016/j.ejmech.2021.113442] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/22/2021] [Accepted: 04/02/2021] [Indexed: 01/03/2023]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is becoming dangerous to human beings due to easy transmission mode and leading to the difficult-to-treat situation. The rapid resistance development of MRSA to many approved antibiotics is of major concern. There is a lot of scope to develop novel, efficient, specific, and nontoxic drug candidates to fight against MRSA isolates. The interesting molecular structure and adaptable feature of oxadiazole moiety which are bioisosteres of esters and amides, and these functional groups show improved resistance to esterases mediated hydrolytic cleavage, attracting researchers to develop required novel antibiotics based on oxadiazole core. This review summarizes the developments of oxadiazole-containing derivatives as potent antibacterial agents against multidrug-resistant MRSA strains and discussing the structure-activity relationship (SAR) in various directions. The current survey is the highlight of the present scenario of oxadiazole hybrids on MRSA studies, covering articles published from 2011 to 2020. This collective information may become a good platform to plan and develop new oxadiazole-based small molecule growth inhibitors of MRSA with minimal side effects.
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Affiliation(s)
- Santosh Kumar Verma
- School of Chemistry and Chemical Engineering, Yulin University, Yulin, 719000, Shaanxi, PR China; Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin University, Yulin, 719000, Shaanxi, PR China
| | - Rameshwari Verma
- School of Chemistry and Chemical Engineering, Yulin University, Yulin, 719000, Shaanxi, PR China; Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin University, Yulin, 719000, Shaanxi, PR China.
| | | | - Laxmi Banjare
- School of Pharmaceutical Sciences, Guru Ghasidas Central University, Bilaspur, Koni, 495009, Chhattisgarh, India
| | - Afzal B Shaik
- Department of Pharmaceutical Chemistry, Vignan Pharmacy College, Jawaharlal Nehru Technological University, Vadlamudi, 522213, Andhra Pradesh, India
| | - Richie R Bhandare
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman, United Arab Emirates; Centre of Medical and Bio-allied Health Sciences Research, Ajman Uniersity, Ajman, United Arab Emirates
| | - Kadalipura P Rakesh
- School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, 430073, PR China
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Fisher JF, Mobashery S. β-Lactams against the Fortress of the Gram-Positive Staphylococcus aureus Bacterium. Chem Rev 2021; 121:3412-3463. [PMID: 33373523 PMCID: PMC8653850 DOI: 10.1021/acs.chemrev.0c01010] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The biological diversity of the unicellular bacteria-whether assessed by shape, food, metabolism, or ecological niche-surely rivals (if not exceeds) that of the multicellular eukaryotes. The relationship between bacteria whose ecological niche is the eukaryote, and the eukaryote, is often symbiosis or stasis. Some bacteria, however, seek advantage in this relationship. One of the most successful-to the disadvantage of the eukaryote-is the small (less than 1 μm diameter) and nearly spherical Staphylococcus aureus bacterium. For decades, successful clinical control of its infection has been accomplished using β-lactam antibiotics such as the penicillins and the cephalosporins. Over these same decades S. aureus has perfected resistance mechanisms against these antibiotics, which are then countered by new generations of β-lactam structure. This review addresses the current breadth of biochemical and microbiological efforts to preserve the future of the β-lactam antibiotics through a better understanding of how S. aureus protects the enzyme targets of the β-lactams, the penicillin-binding proteins. The penicillin-binding proteins are essential enzyme catalysts for the biosynthesis of the cell wall, and understanding how this cell wall is integrated into the protective cell envelope of the bacterium may identify new antibacterials and new adjuvants that preserve the efficacy of the β-lactams.
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Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
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10
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Chang M, Mahasenan KV, Hermoso JA, Mobashery S. Unconventional Antibacterials and Adjuvants. Acc Chem Res 2021; 54:917-929. [PMID: 33512995 DOI: 10.1021/acs.accounts.0c00776] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The need for new classes of antibacterials is genuine in light of the dearth of clinical options for the treatment of bacterial infections. The prodigious discoveries of antibiotics during the 1940s to 1970s, a period wistfully referred to as the Golden Age of Antibiotics, have not kept up in the face of emergence of resistant bacteria in the past few decades. There has been a renewed interest in old drugs, the repurposing of the existing antibiotics and pairing of synergistic antibiotics or of an antibiotic with an adjuvant. Notwithstanding, discoveries of novel classes of these life-saving drugs have become increasingly difficult, calling for new paradigms. We describe, herein, three strategies from our laboratories toward discoveries of new antibacterials and adjuvants using computational and multidisciplinary experimental methods. One approach targets penicillin-binding proteins (PBPs), biosynthetic enzymes of cell-wall peptidoglycan, for discoveries of non-β-lactam inhibitors. Oxadiazoles and quinazolinones emerged as two structural classes out of these efforts. Several hundred analogs of these two classes of antibiotics have been synthesized and fully characterized in our laboratories. A second approach ventures into inhibition of allosteric regulation of cell-wall biosynthesis. The mechanistic details of allosteric regulation of PBP2a of Staphylococcus aureus, discovered in our laboratories, is outlined. The allosteric site in this protein is at 60 Å distance to the active site, whereby ligand binding at the former makes access to the latter by the substrate possible. We have documented that both quinazolinones and ceftaroline, a fifth-generation cephalosporin, bind to the allosteric site in manifestation of the antibacterial activity. Attempts at inhibition of the regulatory phosphorylation events identified three classes of antibacterial adjuvants and one class of antibacterials, the picolinamides. The chemical structures for these hits went through diversification by synthesis of hundreds of analogs. These analogs were characterized in various assays for identification of leads with adjuvant and antibacterial activities. Furthermore, we revisited the mechanism of bulgecins, a class of adjuvants discovered and abandoned in the 1980s. These compounds potentiate the activities of β-lactam antibiotics by the formation of bulges at the sites of septum formation during bacterial replication, which are points of structural weakness in the envelope. These bulges experience rupture, which leads to bacterial death. Bulgecin A inhibits the lytic transglycosylase Slt of Pseudomonas aeruginosa as a likely transition-state mimetic for its turnover of the cell-wall peptidoglycan. Once damage to cell wall is inflicted by a β-lactam antibiotic, the function of Slt is to repair the damage. When Slt is inhibited by bulgecin A, the organism cannot cope with it and would undergo rapid lysis. Bulgecin A is an effective adjuvant of β-lactam antibiotics. These discoveries of small-molecule classes of antibacterials or of adjuvants to antibacterials hold promise in strategies for treatment of bacterial infections.
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Affiliation(s)
- Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, McCourtney Hall, Notre Dame Indiana 46556, United States
| | - Kiran V. Mahasenan
- Department of Chemistry and Biochemistry, University of Notre Dame, McCourtney Hall, Notre Dame Indiana 46556, United States
| | - Juan A. Hermoso
- Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física “Rocasolano”, CSIC, Serrano 119, 28006-Madrid Spain
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, McCourtney Hall, Notre Dame Indiana 46556, United States
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11
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Tarasenko MV, Presnukhina SI, Baikov SV, Shetnev AA. Synthesis and Evaluation of Antibacterial Activity of 1,2,4-Oxadiazole-Containing Biphenylcarboxylic Acids. RUSS J GEN CHEM+ 2020. [DOI: 10.1134/s1070363220090042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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12
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Frank MW, Yao J, Batte JL, Gullett JM, Subramanian C, Rosch JW, Rock CO. Host Fatty Acid Utilization by Staphylococcus aureus at the Infection Site. mBio 2020; 11:e00920-20. [PMID: 32430471 PMCID: PMC7240157 DOI: 10.1128/mbio.00920-20] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 04/20/2020] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus utilizes the fatty acid (FA) kinase system to activate exogenous FAs for membrane synthesis. We developed a lipidomics workflow to determine the membrane phosphatidylglycerol (PG) molecular species synthesized by S. aureus at the thigh infection site. Wild-type S. aureus utilizes both host palmitate and oleate to acylate the 1 position of PG, and the 2 position is occupied by pentadecanoic acid arising from de novo biosynthesis. Inactivation of FakB2 eliminates the ability to assimilate oleate and inactivation of FakB1 reduces the content of saturated FAs and enhances oleate utilization. Elimination of FA activation in either ΔfakA or ΔfakB1 ΔfakB2 mutants does not impact growth. All S. aureus strains recovered from the thigh have significantly reduced branched-chain FAs and increased even-chain FAs compared to that with growth in rich laboratory medium. The molecular species pattern observed in the thigh was reproduced in the laboratory by growth in isoleucine-deficient medium containing exogenous FAs. S. aureus utilizes specific host FAs for membrane biosynthesis but also requires de novo FA biosynthesis initiated by isoleucine (or leucine) to produce pentadecanoic acid.IMPORTANCE The shortage of antibiotics against drug-resistant Staphylococcus aureus has led to the development of new drugs targeting the elongation cycle of fatty acid (FA) synthesis that are progressing toward the clinic. An objection to the use of FA synthesis inhibitors is that S. aureus can utilize exogenous FAs to construct its membrane, suggesting that the bacterium would bypass these therapeutics by utilizing host FAs instead. We developed a mass spectrometry workflow to determine the composition of the S. aureus membrane at the infection site to directly address how S. aureus uses host FAs. S. aureus strains that cannot acquire host FAs are as effective in establishing an infection as the wild type, but strains that require the utilization of host FAs for growth were attenuated in the mouse thigh infection model. We find that S. aureus does utilize host FAs to construct its membrane, but host FAs do not replace the requirement for pentadecanoic acid, a branched-chain FA derived from isoleucine (or leucine) that predominantly occupies the 2 position of S. aureus phospholipids. The membrane phospholipid structure of S. aureus mutants that cannot utilize host FAs indicates the isoleucine is a scarce resource at the infection site. This reliance on the de novo synthesis of predominantly pentadecanoic acid that cannot be obtained from the host is one reason why drugs that target fatty acid synthesis are effective in treating S. aureus infections.
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Affiliation(s)
- Matthew W Frank
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jiangwei Yao
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Justin L Batte
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jessica M Gullett
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Chitra Subramanian
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jason W Rosch
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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13
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Shalaby MAW, Dokla EME, Serya RAT, Abouzid KAM. Penicillin binding protein 2a: An overview and a medicinal chemistry perspective. Eur J Med Chem 2020; 199:112312. [PMID: 32442851 DOI: 10.1016/j.ejmech.2020.112312] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/28/2020] [Accepted: 04/05/2020] [Indexed: 12/17/2022]
Abstract
Antimicrobial resistance is an imminent threat worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the "superbug" family, manifesting resistance through the production of a penicillin binding protein, PBP2a, an enzyme that provides its transpeptidase activity to allow cell wall biosynthesis. PBP2a's low affinity to most β-lactams, confers resistance to MRSA against numerous members of this class of antibiotics. An Achilles' heel of MRSA, PBP2a represents a substantial target to design novel antibiotics to tackle MRSA threat via inhibition of the bacterial cell wall biosynthesis. In this review we bring into focus the PBP2a enzyme and examine the various aspects related to its role in conferring resistance to MRSA strains. Moreover, we discuss several antibiotics and antimicrobial agents designed to target PBP2a and their therapeutic potential to meet such a grave threat. In conclusion, we consider future perspectives for targeting MRSA infections.
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Affiliation(s)
- Menna-Allah W Shalaby
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Eman M E Dokla
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt.
| | - Rabah A T Serya
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Khaled A M Abouzid
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt; Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Sadat City, Sadat City, Egypt.
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14
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Boudreau MA, Ding D, Meisel JE, Janardhanan J, Spink E, Peng Z, Qian Y, Yamaguchi T, Testero SA, O’Daniel PI, Leemans E, Lastochkin E, Song W, Schroeder VA, Wolter WR, Suckow MA, Mobashery S, Chang M. Structure-Activity Relationship for the Oxadiazole Class of Antibacterials. ACS Med Chem Lett 2020; 11:322-326. [PMID: 32184964 DOI: 10.1021/acsmedchemlett.9b00379] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/03/2019] [Indexed: 11/29/2022] Open
Abstract
A structure-activity relationship (SAR) for the oxadiazole class of antibacterials was evaluated by syntheses of 72 analogs and determination of the minimal-inhibitory concentrations (MICs) against the ESKAPE panel of bacteria. Selected compounds were further evaluated for in vitro toxicity, plasma protein binding, pharmacokinetics (PK), and a mouse model of methicillin-resistant Staphylococcus aureus (MRSA) infection. Oxadiazole 72c shows potent in vitro antibacterial activity, exhibits low clearance, a high volume of distribution, and 41% oral bioavailability, and shows efficacy in mouse models of MRSA infection.
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Affiliation(s)
- Marc A. Boudreau
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Derong Ding
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jayda E. Meisel
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jeshina Janardhanan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Edward Spink
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Zhihong Peng
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Yuanyuan Qian
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Takao Yamaguchi
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Sebastian A. Testero
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Peter I. O’Daniel
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Erika Leemans
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Elena Lastochkin
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Wei Song
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Valerie A. Schroeder
- Freimann Life Sciences Center and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - William R. Wolter
- Freimann Life Sciences Center and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Mark A. Suckow
- Freimann Life Sciences Center and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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15
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Fisher JF, Mobashery S. Constructing and deconstructing the bacterial cell wall. Protein Sci 2020; 29:629-646. [PMID: 31747090 PMCID: PMC7021008 DOI: 10.1002/pro.3737] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 12/11/2022]
Abstract
The history of modern medicine cannot be written apart from the history of the antibiotics. Antibiotics are cytotoxic secondary metabolites that are isolated from Nature. The antibacterial antibiotics disproportionately target bacterial protein structure that is distinct from eukaryotic protein structure, notably within the ribosome and within the pathways for bacterial cell-wall biosynthesis (for which there is not a eukaryotic counterpart). This review focuses on a pre-eminent class of antibiotics-the β-lactams, exemplified by the penicillins and cephalosporins-from the perspective of the evolving mechanisms for bacterial resistance. The mechanism of action of the β-lactams is bacterial cell-wall destruction. In the monoderm (single membrane, Gram-positive staining) pathogen Staphylococcus aureus the dominant resistance mechanism is expression of a β-lactam-unreactive transpeptidase enzyme that functions in cell-wall construction. In the diderm (dual membrane, Gram-negative staining) pathogen Pseudomonas aeruginosa a dominant resistance mechanism (among several) is expression of a hydrolytic enzyme that destroys the critical β-lactam ring of the antibiotic. The key sensing mechanism used by P. aeruginosa is monitoring the molecular difference between cell-wall construction and cell-wall deconstruction. In both bacteria, the resistance pathways are manifested only when the bacteria detect the presence of β-lactams. This review summarizes how the β-lactams are sensed and how the resistance mechanisms are manifested, with the expectation that preventing these processes will be critical to future chemotherapeutic control of multidrug resistant bacteria.
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Affiliation(s)
- Jed F. Fisher
- Department of Chemistry and BiochemistryUniversity of Notre DameSouth BendIndiana
| | - Shahriar Mobashery
- Department of Chemistry and BiochemistryUniversity of Notre DameSouth BendIndiana
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16
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Synergistic anti-methicillin-resistant Staphylococcus aureus (MRSA) activity and absolute stereochemistry of 7,8-dideoxygriseorhodin C. J Antibiot (Tokyo) 2020; 73:290-298. [PMID: 31992865 PMCID: PMC7125055 DOI: 10.1038/s41429-019-0275-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/16/2019] [Accepted: 12/20/2019] [Indexed: 02/07/2023]
Abstract
The emergence of antibiotic resistance necessitates not only the identification of new compounds with antimicrobial properties, but also new strategies and combination therapies to circumvent this growing problem. Here, we report synergistic activity against methicillin-resistant Staphylococcus aureus (MRSA) of the β-lactam antibiotic oxacillin combined with 7,8-dideoxygriseorhodin C in vitro. Ongoing efforts to identify antibiotics from marine mollusk-associated bacteria resulted in the isolation of 7,8-dideoxygriseorhodin C from a Streptomyces sp. strain cultivated from a marine gastropod tissue homogenate. Despite the long history of 7,8-dideoxygriseorhodin C in the literature, the absolute configuration has never been previously reported. A comparison of measured and calculated ECD spectra resolved the configuration of the spiroketal carbon C6, and 2D ROESY NMR spectroscopy established the absolute configuration as 6s,6aS. The compound is selective against Gram-positive bacteria including MRSA and Enterococcus faecium with an MIC range of 0.125-0.5 μg ml-1. Moreover, the compound synergizes with oxacillin against MRSA as observed in the antimicrobial microdilution and time-kill assays. Simultaneous treatment of the compound with oxacillin resulted in an approximately tenfold decrease in MIC with a combination index of <0.5, indicating synergistic anti-MRSA activity.
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17
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Konai MM, Haldar J. Lysine-Based Small Molecule Sensitizes Rifampicin and Tetracycline against Multidrug-Resistant Acinetobacter baumannii and Pseudomonas aeruginosa. ACS Infect Dis 2020; 6:91-99. [PMID: 31646866 DOI: 10.1021/acsinfecdis.9b00221] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The priority pathogen list published by the World Health Organization (WHO) has categorized carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa as the top two critical pathogens, and hence, the development of novel antibacterial strategies to tackle such bacteria is highly necessary. Toward this aim, herein we report the efficacy of the combination of a lysine-based membrane-active small molecule, D-LANA-14 (d-lysine conjugated aliphatic norspermidine analogue bearing tetradecanoyl chain) and the obsolete/inactive antibiotics (such as tetracycline and rifampicin) to combat these superbugs. The combination of D-LANA-14 and the antibiotics tetracycline or rifampicin showed not only synergistic activity against growing planktonic cells of meropenem-resistant A. baumannii and P. aeruginosa clinical isolates but was also able to disrupt their established biofilms. More importantly, this synergistic effect was retained under the in vivo scenario, wherein the combination showed excellent efficacy in mice model of burn-wound infection with a drastic reduction of bacterial burden. A combined treatment of D-LANA-14 (40 mg/kg) and rifampicin (40 mg/kg) showed 4.9 log and 4.0 log reduction in A. baumannii and P. aeruginosa viability, respectively. On the contrary, individual treatment of D-LANA-14 decreased bacterial burden by 2.3 log (A. baumannii) and 1.3 log (P. aeruginosa) and rifampicin reduced about 3.0 log (A. baumannii) and 1.6 log (P. aeruginosa). Owing to the membrane-active nature imparted by D-LANA-14, bacteria could not develop resistance against the combined treatment, whereas a high-level of resistance development was observed against the last resort Gram-negative antibiotic, colistin. Taken together, the results therefore indicate a great potential of this novel combination to be developed as therapeutic regimen to combat infections caused by critical Gram-negative pathogens.
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Affiliation(s)
- Mohini Mohan Konai
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Jayanta Haldar
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
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18
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Wang Q, Lv Y, Pang J, Li X, Lu X, Wang X, Hu X, Nie T, Yang X, Xiong YQ, Jiang J, Li C, You X. In vitro and in vivo activity of d-serine in combination with β-lactam antibiotics against methicillin-resistant Staphylococcus aureus. Acta Pharm Sin B 2019; 9:496-504. [PMID: 31193801 PMCID: PMC6543093 DOI: 10.1016/j.apsb.2019.01.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 12/16/2018] [Accepted: 12/20/2018] [Indexed: 12/31/2022] Open
Abstract
As d-amino acids play important roles in the physiological metabolism of bacteria, combination of d-amino acids with antibiotics may provide synergistic antibacterial activity. The aim of the study was to evaluate in vitro and in vivo activity of d-serine alone and in combination with β-lactams against methicillin-resistant Staphylococcus aureus (MRSA) strains, and to explore the possible sensitization mechanisms. The activity of d-serine, β-lactams alone and in combinations was evaluated both in vitro by standard MICs, time-kill curves and checkerboard assays, and in vivo by murine systemic infection model as well as neutropenic thigh infection model. An in vitro synergistic effect was demonstrated with the combination of d-serine and β-lactams against MRSA standard and clinical strains. Importantly, the combinations enhanced the therapeutic efficacy in the animal models as compared to β-lactam alone groups. Initial mechanism study suggested possible revision of d-alanine-d-alanine residue to d-alanine-d-serine in peptidoglycan by adding of d-alanine in the medium, which may cause decreased affinity to PBPs during transpeptidation. In conclusion, d-serine had synergistic activity in combination with β-lactams against MRSA strains both in vitro and in vivo. Considering the relatively good safety of d-serine alone or in combination with β-lactams, d-serine is worth following up as new anti-MRSA infection strategies.
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Affiliation(s)
- Qing Wang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Yuemeng Lv
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jing Pang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xue Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xi Lu
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xiukun Wang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xinxin Hu
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Tongying Nie
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xinyi Yang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Yan Q. Xiong
- Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jiandong Jiang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Congran Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Corresponding authors. Tel.: +86 10 67058991, +86 10 67061033; fax +86 10 63017302.
| | - Xuefu You
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Corresponding authors. Tel.: +86 10 67058991, +86 10 67061033; fax +86 10 63017302.
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19
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The Quinazolinone Allosteric Inhibitor of PBP 2a Synergizes with Piperacillin and Tazobactam against Methicillin-Resistant Staphylococcus aureus. Antimicrob Agents Chemother 2019; 63:AAC.02637-18. [PMID: 30858202 DOI: 10.1128/aac.02637-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/05/2019] [Indexed: 12/20/2022] Open
Abstract
The quinazolinones are a new class of antibacterials with in vivo efficacy against methicillin-resistant Staphylococcus aureus (MRSA). The quinazolinones target cell wall biosynthesis and have a unique mechanism of action by binding to the allosteric site of penicillin-binding protein 2a (PBP 2a). We investigated the potential for synergism of a lead quinazolinone with several antibiotics of different classes using checkerboard and time-kill assays. The quinazolinone synergized with β-lactam antibiotics. The combination of the quinazolinone with commercial piperacillin-tazobactam showed bactericidal synergy at sub-MICs of all three drugs. We demonstrated the efficacy of the triple-drug combination in a mouse MRSA neutropenic thigh infection model. The proposed mechanism for the synergistic activity in MRSA involves inhibition of the β-lactamase by tazobactam, which protects piperacillin from hydrolysis, which can then inhibit its target, PBP 2. Furthermore, the quinazolinone binds to the allosteric site of PBP 2a, triggering the allosteric response. This leads to the opening of the active site, which, in turn, binds another molecule of piperacillin. In other words, PBP 2a, which is not normally inhibited by piperacillin, becomes vulnerable to inhibition in the presence of the quinazolinone. The collective effect is the impairment of cell wall biosynthesis, with bactericidal consequence. Two crystal structures for complexes of the antibiotics with PBP 2a provide support for the proposed mechanism of action.
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20
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Shetnev A, Baykov S, Kalinin S, Belova A, Sharoyko V, Rozhkov A, Zelenkov L, Tarasenko M, Sadykov E, Korsakov M, Krasavin M. 1,2,4-Oxadiazole/2-Imidazoline Hybrids: Multi-target-directed Compounds for the Treatment of Infectious Diseases and Cancer. Int J Mol Sci 2019; 20:ijms20071699. [PMID: 30959765 PMCID: PMC6480344 DOI: 10.3390/ijms20071699] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/31/2019] [Accepted: 04/03/2019] [Indexed: 12/25/2022] Open
Abstract
Replacement of amide moiety with the 1,2,4-oxadiazole core in the scaffold of recently reported efflux pump inhibitors afforded a novel series of oxadiazole/2-imidazoline hybrids. The latter compounds exhibited promising antibacterial activity on both Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonasfluorescens) strains. Furthermore, selected compounds markedly inhibited the growth of certain drug-resistant bacteria. Additionally, the study revealed the antiproliferative activity of several antibacterial frontrunners against pancreas ductal adenocarcinoma (PANC-1) cell line, as well as their type-selective monoamine oxidase (MAO) inhibitory profile.
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Affiliation(s)
- Anton Shetnev
- Pharmaceutical Technology Transfer Center, Ushinsky Yaroslavl State Pedagogical University, 108 Respublikanskaya St., Yaroslavl 150000, Russia.
| | - Sergey Baykov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii Pr, Peterhof, Saint Petersburg 198504, Russia.
| | - Stanislav Kalinin
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii Pr, Peterhof, Saint Petersburg 198504, Russia.
| | - Alexandra Belova
- Pharmaceutical Technology Transfer Center, Ushinsky Yaroslavl State Pedagogical University, 108 Respublikanskaya St., Yaroslavl 150000, Russia.
| | - Vladimir Sharoyko
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii Pr, Peterhof, Saint Petersburg 198504, Russia.
| | - Anton Rozhkov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii Pr, Peterhof, Saint Petersburg 198504, Russia.
| | - Lev Zelenkov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii Pr, Peterhof, Saint Petersburg 198504, Russia.
| | - Marina Tarasenko
- Yaroslavl State Technical University, 88 Moscowsky Pr, Yaroslavl 150023, Russia.
| | - Evgeny Sadykov
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch Russian Academy of Science, 1 Favorsky Str, Irkutsk 664033, Russian.
| | - Mikhail Korsakov
- Pharmaceutical Technology Transfer Center, Ushinsky Yaroslavl State Pedagogical University, 108 Respublikanskaya St., Yaroslavl 150000, Russia.
| | - Mikhail Krasavin
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii Pr, Peterhof, Saint Petersburg 198504, Russia.
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21
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Boles LR, Awais R, Beenken KE, Smeltzer MS, Haggard WO, Jessica AJ. Local Delivery of Amikacin and Vancomycin from Chitosan Sponges Prevent Polymicrobial Implant-Associated Biofilm. Mil Med 2019; 183:459-465. [PMID: 29635622 DOI: 10.1093/milmed/usx161] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 12/27/2017] [Indexed: 01/01/2023] Open
Abstract
Military personnel have high risk for infection, particularly those with combat-related extremity trauma. Administration of multiple or broad-spectrum antibiotics provides clinicians with a strategy for preventing biofilm-based medical device infections. Selection of effective antibiotic combinations based on common pathogens may be used to improve chitosan wound dressing sponge-based local antibiotic delivery systems. In vitro assays in this study demonstrate that vancomycin and amikacin have a synergistic relationship against a strain of osteomyelitis-producing Gram-positive Staphylococcus aureus, although an indifferent relationship was observed against Gram-negative Pseudomonas aeruginosa. In an in vivo model of orthopedic hardware-associated polymicrobial (S. aureus and Escherichia coli) biofilm, chitosan sponges loaded with a combination of vancomycin and amikacin at 5 mg/mL each showed a greater percentage of complete clearance, 50%, than either antibiotic alone, 8.33%. Doubling the loading concentration of the combination achieved a complete clearance rate of 100%, a four log-fold reduction of S. aureus on the wire and a six log-fold reduction in bone. E. coli was detected in bone of untreated animals but did not form biofilm on wires. Results demonstrate the clinical potential of chitosan sponges to prevent infection and illustrates antibiotic selection and loading concentrations necessary for effective biofilm prevention.
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Affiliation(s)
- Logan R Boles
- Department of Biomedical Engineering, University of Memphis, 3796 Norriswood Avenue, Memphis, TN 38111
| | - Rukhsana Awais
- Department of Biomedical Engineering, University of Memphis, 3796 Norriswood Avenue, Memphis, TN 38111
| | - Karen E Beenken
- Department of Microbiology and Immunology University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205
| | - Mark S Smeltzer
- Department of Microbiology and Immunology University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205
| | - Warren O Haggard
- Department of Biomedical Engineering, University of Memphis, 3796 Norriswood Avenue, Memphis, TN 38111
| | - Amber Jennings Jessica
- Department of Biomedical Engineering, University of Memphis, 3796 Norriswood Avenue, Memphis, TN 38111
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22
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Ceballos S, Kim C, Ding D, Mobashery S, Chang M, Torres C. Activities of Oxadiazole Antibacterials against Staphylococcus aureus and Other Gram-Positive Bacteria. Antimicrob Agents Chemother 2018; 62:e00453-18. [PMID: 29866865 PMCID: PMC6105842 DOI: 10.1128/aac.00453-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/26/2018] [Indexed: 12/13/2022] Open
Abstract
The activities of four oxadiazoles were investigated with 210 methicillin-resistant Staphylococcus aureus (MRSA) strains. MIC50 and MIC90 values of 1 to 2 and 4 μg/ml, respectively, were observed. We also evaluated the activity of oxadiazole ND-421 against other staphylococci and enterococci and in the presence of oxacillin for selected MRSA strains. The MIC for ND-421 is lowered severalfold in combination with oxacillin, as they synergize. The MIC90 of ND-421 against vancomycin-resistant enterococci is ≤1 μg/ml.
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Affiliation(s)
- Sara Ceballos
- Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Choon Kim
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Derong Ding
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Carmen Torres
- Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
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23
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Carter GP, Harjani JR, Li L, Pitcher NP, Nong Y, Riley TV, Williamson DA, Stinear TP, Baell JB, Howden BP. 1,2,4-Oxadiazole antimicrobials act synergistically with daptomycin and display rapid kill kinetics against MDR Enterococcus faecium. J Antimicrob Chemother 2018. [DOI: 10.1093/jac/dky064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Glen P Carter
- Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
- Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Jitendra R Harjani
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
| | - Lucy Li
- Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Noel P Pitcher
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
| | - Yi Nong
- Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Thomas V Riley
- School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
- Department of Microbiology, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Deborah A Williamson
- Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
- Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Timothy P Stinear
- Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Jonathan B Baell
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Benjamin P Howden
- Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
- Department of Microbiology & Immunology, Doherty Institute, The University of Melbourne, Melbourne, Australia
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24
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Yeo WS, Arya R, Kim KK, Jeong H, Cho KH, Bae T. The FDA-approved anti-cancer drugs, streptozotocin and floxuridine, reduce the virulence of Staphylococcus aureus. Sci Rep 2018; 8:2521. [PMID: 29410445 PMCID: PMC5802796 DOI: 10.1038/s41598-018-20617-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/17/2018] [Indexed: 01/30/2023] Open
Abstract
In Staphylococcus aureus, an important Gram-positive human pathogen, the SaeRS two-component system is essential for the virulence and a good target for the development of anti-virulence drugs. In this study, we screened 12,200 small molecules for Sae inhibitors and identified two anti-cancer drugs, streptozotocin (STZ) and floxuridine (FU), as lead candidates for anti-virulence drug development against staphylococcal infections. As compared with STZ, FU was more efficient in repressing Sae-regulated promoters and protecting human neutrophils from S. aureus-mediated killing. FU inhibited S. aureus growth effectively whereas STZ did not. Intriguingly, RNA-seq analysis suggests that both compounds inhibit other virulence-regulatory systems such as Agr, ArlRS, and SarA more efficiently than they inhibit the Sae system. Both compounds induced prophages from S. aureus, indicating that they cause DNA damages. Surprisingly, a single administration of the drugs was sufficient to protect mice from staphylococcal intraperitoneal infection. Both compounds showed in vivo efficacy in a murine model of blood infection too. Finally, at the experimental dosage, neither compound showed any noticeable side effects on blood glucose level or blood cell counts. Based on these results, we concluded that STZ and FU are promising candidates for anti-virulence drug development against S. aureus infection.
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Affiliation(s)
- Won-Sik Yeo
- Department of Microbiology and Immunology, Indiana University School of Medicine-Northwest, Gary, Indiana, 46408, USA
| | - Rekha Arya
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Suwon, 16419, Korea
| | - Kyeong Kyu Kim
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Suwon, 16419, Korea
| | - Hyunyoung Jeong
- Departments of Pharmacy Practice and Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, 60607, USA
| | - Kyu Hong Cho
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA
| | - Taeok Bae
- Department of Microbiology and Immunology, Indiana University School of Medicine-Northwest, Gary, Indiana, 46408, USA.
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