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Butler MS, Vollmer W, Goodall ECA, Capon RJ, Henderson IR, Blaskovich MAT. A Review of Antibacterial Candidates with New Modes of Action. ACS Infect Dis 2024. [PMID: 39018341 DOI: 10.1021/acsinfecdis.4c00218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/19/2024]
Abstract
There is a lack of new antibiotics to combat drug-resistant bacterial infections that increasingly threaten global health. The current pipeline of clinical-stage antimicrobials is primarily populated by "new and improved" versions of existing antibiotic classes, supplemented by several novel chemical scaffolds that act on traditional targets. The lack of fresh chemotypes acting on previously unexploited targets (the "holy grail" for new antimicrobials due to their scarcity) is particularly unfortunate as these offer the greatest opportunity for innovative breakthroughs to overcome existing resistance. In recognition of their potential, this review focuses on this subset of high value antibiotics, providing chemical structures where available. This review focuses on candidates that have progressed to clinical trials, as well as selected examples of promising pioneering approaches in advanced stages of development, in order to stimulate additional research aimed at combating drug-resistant infections.
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Affiliation(s)
- Mark S Butler
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Waldemar Vollmer
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Emily C A Goodall
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Robert J Capon
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Ian R Henderson
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
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2
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Quan M, Zhang X, Fang Q, Lv X, Wang X, Zong Z. Fighting against Clostridioides difficile infection: Current medications. Int J Antimicrob Agents 2024; 64:107198. [PMID: 38734214 DOI: 10.1016/j.ijantimicag.2024.107198] [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: 12/08/2023] [Revised: 04/18/2024] [Accepted: 05/04/2024] [Indexed: 05/13/2024]
Abstract
Clostridioides difficile (formerly Clostridium difficile) has been regarded as an 'urgent threat' and a significant global health problem, as life-threatening diarrhoea and refractory recurrence are common in patients with C. difficile infection (CDI). Unfortunately, the available anti-CDI drugs are limited. Recent guidelines recommend fidaxomicin and vancomycin as first-line drugs to treat CDI, bezlotoxumab to prevent recurrence, and faecal microbiota transplantation for rescue treatment. Currently, researchers are investigating therapeutic antibacterial drugs (e.g. teicoplanin, ridinilazole, ibezapolstat, surotomycin, cadazolid, and LFF571), preventive medications against recurrence (e.g. Rebyota, Vowst, VP20621, VE303, RBX7455, and MET-2), primary prevention strategies (e.g. vaccine, ribaxamase, and DAV132) and other anti-CDI medications in the preclinical stage (e.g. Raja 42, Myxopyronin B, and bacteriophage). This narrative review summarises current medications, including newly marketed drugs and products in development against CDI, to help clinicians treat CDI appropriately and to call for more research on innovation.
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Affiliation(s)
- Min Quan
- Center for Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China
| | - Xiaoxia Zhang
- Center for Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China
| | - Qingqing Fang
- Center for Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China
| | - Xiaoju Lv
- Center for Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China; Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, China
| | - Xiaohui Wang
- Center for Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China; Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, China.
| | - Zhiyong Zong
- Center for Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China; Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, China
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3
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Bassères E, Eubank TA, Begum K, Alam MJ, Jo J, Le TM, Lancaster CK, Gonzales-Luna AJ, Garey KW. Antibacterial activity of ibezapolstat against antimicrobial-resistant clinical strains of Clostridioides difficile. Antimicrob Agents Chemother 2024; 68:e0162123. [PMID: 38364016 PMCID: PMC10916401 DOI: 10.1128/aac.01621-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/25/2024] [Indexed: 02/18/2024] Open
Abstract
Antimicrobial resistance is emerging in clinical strains of Clostridioides difficile. Ibezapolstat (IBZ) is a DNA polymerase IIIC inhibitor that has completed phase II clinical trials. IBZ has potent in vitro activity against wild-type, susceptible strains but its effect on C. difficile strains with reduced susceptibility to metronidazole (MTZ), vancomycin (VAN), or fidaxomicin (FDX) has not been tested. The primary objective of this study was to test the antibacterial properties of IBZ against multidrug-resistant C. difficile strains. The in vitro activity, bactericidal, and time-kill activity of IBZ versus comparators were evaluated against 100 clinical strains of which 59 had reduced susceptibility to other C. difficile antibiotics. Morphologic changes against a multidrug resistance strain were visualized by light and scanning electron microscopy. The overall IBZ MIC50/90 values (µg/mL) for evaluated C. difficile strains were 4/8, compared with 2/4 for VAN, 0.5/1 for FDX, and 0.25/4 for MTZ. IBZ MIC50/90 values did not differ based on non-susceptibility to antibiotic class or number of classes to which strains were non-susceptible. IBZ bactericidal activity was similar to the minimum inhibitory concentration (MIC) and maintained in wild-type and non-susceptible strains. Time-kill assays against two laboratory wild-type and two clinical non-susceptible strains demonstrated sustained IBZ activity despite reduced killing by comparator antibiotics for IBZ and VAN non-susceptible strains. Microscopy visualized increased cell lengthening and cellular damage in multidrug-resistant strains exposed to IBZ sub-MIC concentrations. This study demonstrated the potent antibacterial activity of IBZ against a large collection of C. difficile strains including multidrug-resistant strains. This study highlights the therapeutic potential of IBZ against multidrug-resistant strains of C. difficile.
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Affiliation(s)
- Eugénie Bassères
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Taryn A. Eubank
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Khurshida Begum
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - M. Jahangir Alam
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Jinhee Jo
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Thanh M. Le
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Chris K. Lancaster
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Anne J. Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Kevin W. Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
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4
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Buddle JE, Fagan RP. Pathogenicity and virulence of Clostridioides difficile. Virulence 2023; 14:2150452. [PMID: 36419222 DOI: 10.1080/21505594.2022.2150452] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/02/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Clostridioides difficile is the most common cause of nosocomial antibiotic-associated diarrhea, and is responsible for a spectrum of diseases characterized by high levels of recurrence, morbidity, and mortality. Treatment is complex, since antibiotics constitute both the main treatment and the major risk factor for infection. Worryingly, resistance to multiple antibiotics is becoming increasingly widespread, leading to the classification of this pathogen as an urgent threat to global health. As a consummate opportunist, C. difficile is well equipped for promoting disease, owing to its arsenal of virulence factors: transmission of this anaerobe is highly efficient due to the formation of robust endospores, and an array of adhesins promote gut colonization. C. difficile produces multiple toxins acting upon gut epithelia, resulting in manifestations typical of diarrheal disease, and severe inflammation in a subset of patients. This review focuses on such virulence factors, as well as the importance of antimicrobial resistance and genome plasticity in enabling pathogenesis and persistence of this important pathogen.
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Affiliation(s)
- Jessica E Buddle
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Robert P Fagan
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, UK
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Butler MS, Henderson IR, Capon RJ, Blaskovich MAT. Antibiotics in the clinical pipeline as of December 2022. J Antibiot (Tokyo) 2023; 76:431-473. [PMID: 37291465 PMCID: PMC10248350 DOI: 10.1038/s41429-023-00629-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/20/2023] [Accepted: 04/25/2023] [Indexed: 06/10/2023]
Abstract
The need for new antibacterial drugs to treat the increasing global prevalence of drug-resistant bacterial infections has clearly attracted global attention, with a range of existing and upcoming funding, policy, and legislative initiatives designed to revive antibacterial R&D. It is essential to assess whether these programs are having any real-world impact and this review continues our systematic analyses that began in 2011. Direct-acting antibacterials (47), non-traditional small molecule antibacterials (5), and β-lactam/β-lactamase inhibitor combinations (10) under clinical development as of December 2022 are described, as are the three antibacterial drugs launched since 2020. Encouragingly, the increased number of early-stage clinical candidates observed in the 2019 review increased in 2022, although the number of first-time drug approvals from 2020 to 2022 was disappointingly low. It will be critical to monitor how many Phase-I and -II candidates move into Phase-III and beyond in the next few years. There was also an enhanced presence of novel antibacterial pharmacophores in early-stage trials, and at least 18 of the 26 phase-I candidates were targeted to treat Gram-negative bacteria infections. Despite the promising early-stage antibacterial pipeline, it is essential to maintain funding for antibacterial R&D and to ensure that plans to address late-stage pipeline issues succeed.
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Affiliation(s)
- Mark S Butler
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
| | - Ian R Henderson
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Robert J Capon
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
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6
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Nelson-Rigg R, Fagan SP, Jaremko WJ, Pata JD. Pre-Steady-State Kinetic Characterization of an Antibiotic-Resistant Mutant of Staphylococcus aureus DNA Polymerase PolC. Antimicrob Agents Chemother 2023; 67:e0157122. [PMID: 37222615 PMCID: PMC10269047 DOI: 10.1128/aac.01571-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/17/2023] [Indexed: 05/25/2023] Open
Abstract
The emergence and spread of antibiotic resistance in bacterial pathogens are serious and ongoing threats to public health. Since chromosome replication is essential to cell growth and pathogenesis, the essential DNA polymerases in bacteria have long been targets of antimicrobial development, although none have yet advanced to the market. Here, we use transient-state kinetic methods to characterize the inhibition of the PolC replicative DNA polymerase from Staphylococcus aureus by 2-methoxyethyl-6-(3'-ethyl-4'-methylanilino)uracil (ME-EMAU), a member of the 6-anilinouracil compounds that specifically target PolC enzymes, which are found in low-GC content Gram-positive bacteria. We find that ME-EMAU binds to S. aureus PolC with a dissociation constant of 14 nM, more than 200-fold tighter than the previously reported inhibition constant, which was determined using steady-state kinetic methods. This tight binding is driven by a very slow off rate of 0.006 s-1. We also characterized the kinetics of nucleotide incorporation by PolC containing a mutation of phenylalanine 1261 to leucine (F1261L). The F1261L mutation decreases ME-EMAU binding affinity by at least 3,500-fold but also decreases the maximal rate of nucleotide incorporation by 11.5-fold. This suggests that bacteria acquiring this mutation would be likely to replicate slowly and be unable to out-compete wild-type strains in the absence of inhibitors, reducing the likelihood of the resistant bacteria propagating and spreading resistance.
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Affiliation(s)
- Rachel Nelson-Rigg
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - Sean P. Fagan
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - William J. Jaremko
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Janice D. Pata
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
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7
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New potent ciprofloxacin-uracil conjugates as DNA gyrase and topoisomerase IV inhibitors against methicillin-resistant Staphylococcus aureus. Bioorg Med Chem 2022; 73:117004. [PMID: 36148773 DOI: 10.1016/j.bmc.2022.117004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/20/2022]
Abstract
A series of ciprofloxacin-uracil conjugates 5a-t were synthesized and identified by 1H NMR, 13C NMR, mass spectroscopy and elemental analyses. The antibacterial results revealed that the new derivatives exhibited better activity against Gram-positive than the Gram-negative strains; most of the target compounds exhibited good activities against S. aureus ATCC 6538. Compounds 5b and 5g possess the highest activities with MICs of 1.25 and 2.37 µM, respectively, which are more potent than the parent drug ciprofloxacin, MIC, 7.58 µM. In addition, they also exhibited potent activities against MRSA AUMC 261 with MICs, 0.031 and 0.046 µM respectively, higher than ciprofloxacin with MIC, 0.57 µM. Moreover, compounds 5b and 5g showed potent inhibitory activities against DNA gyrase (IC50 = 1.72 and 5.72 µM) and topoisomerase IV (4.36 and 7.77 µM) compared to ciprofloxacin with IC50 values 0.66 and 8.16 µM, respectively. The molecular docking study revealed that compounds 5b and 5g may formed stable interaction with the active sites of DNA gyrase and topoisomerase IV similar to ciprofloxacin. Hence, 5b and 5g are considered promising antibacterial candidated against MRSA AUMC 261 strains that requires further optimization.
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8
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Mekky AE, Sanad SM, Abdelfattah AM. Tandem synthesis, antibacterial evaluation and SwissADME prediction study of new bis(1,3,4-oxadiazoles) linked to arene units. MENDELEEV COMMUNICATIONS 2022. [DOI: 10.1016/j.mencom.2022.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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9
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Functional and Metagenomic Evaluation of Ibezapolstat for Early Evaluation of Anti-Recurrence Effects in Clostridioides difficile Infection. Antimicrob Agents Chemother 2022; 66:e0224421. [PMID: 35862742 PMCID: PMC9380534 DOI: 10.1128/aac.02244-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reduction of Clostridioides difficile infection (CDI) recurrence is an essential endpoint for CDI-directed antibiotic development that is often not evaluated until Phase III trials. The purpose of this project was to use a functional and metagenomic approach to predict the potential anti-CDI recurrence effect of ibezapolstat, a DNA polymerase IIIC inhibitor, in clinical development for CDI. As part of the Phase I ibezapolstat clinical study, stool samples were collected from 22 healthy volunteers, who were given either ibezapolstat or vancomycin. Stool samples were evaluated for microbiome changes and bile acid concentrations. Ibezapolstat 450 mg and vancomycin, but not ibezapolstat 300 mg, showed statistically significant changes in alpha diversity over time compared to that of a placebo. Beta diversity changes confirmed that microbiota were significantly different between study groups. Vancomycin had a more wide-ranging effect on the microbiome, characterized by an increased proportion of Gammaproteobacteria. Ibezapolstat demonstrated an increased proportion of Actinobacteria, including the Bifidobacteriaceae family. Using a linear regression analysis, vancomycin was associated with significant increases in primary bile acids as well as primary:secondary bile acid ratios. An overabundance of Enterobacteriaceae was most highly correlated with primary bile acid concentrations (r = 0.63; P < 0.0001). Using Phase I healthy volunteer samples, beneficial changes suggestive of a lower risk of CDI recurrence were associated with ibezapolstat compared to vancomycin. This novel omics approach may allow for better and earlier prediction of anti-CDI recurrence effects for antibiotics in the clinical development pipeline.
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Abdelfattah AM, Mekky AEM, Sanad SMH. Synthesis, antibacterial activity and in silico study of new bis(1,3,4-oxadiazoles). SYNTHETIC COMMUN 2022. [DOI: 10.1080/00397911.2022.2095211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
| | - Ahmed E. M. Mekky
- Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt
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11
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Investigation of Morchella esculenta and Morchella conica for their antibacterial potential against methicillin-susceptible Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pyogenes. Arch Microbiol 2022; 204:391. [PMID: 35699800 DOI: 10.1007/s00203-022-03003-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/20/2022] [Indexed: 11/02/2022]
Abstract
Antimicrobial resistance is an alarming problem, especially due to emergence of methicillin-resistance Staphylococcus aureus (MRSA). World Health Organization (WHO) has already listed MRSA as a top priority pathogen for the development of novel antibacterial agents. Presently, different therapeutic approaches against bacterial infections are in practice which includes targeting bacterial virulence factors, bacteriophage therapy, and manipulation of the microbiome. Natural products have been efficiently used for centuries to combat bacterial infections. Morchella is a natural fungal product which has been reported to possess broad-spectrum biological activities against bacterial infections. Hence, this study was aimed to evaluate the antibacterial efficacy of two macro-fungi against S. aureus, MRSA, and Streptococcus pyogenes (S. pyogenes). The antibacterial potential of both fungal extracts (Morchella esculenta and Morchella conica) was evaluated using disk diffusion and standard broth microdilution methods. The chemical compounds of both fungi were investigated using ultra-performance liquid chromatography mass spectroscopy (UPLC-MS) analysis. All fungal extracts inhibited growth of tested bacteria with inhibitory zone ranging from 10.66 ± 0.3 to 21.00 ± 1.5 mm. The minimum inhibitory concentration (MIC) of tested bacterial growth ranged from 03.33 to 16.0 mg/ml. It was noteworthy that Morchella extracts prevented S. aureus growth in a bactericidal manner with minimal bactericidal concentration (MBC) of 8-16 mg/ml. The extracts were also more effective against MRSA than currently available antibiotics. In conclusion, the growth inhibition of tested bacteria by fungal extracts revealed their potential as antibacterial agents and their compounds may be used as drug candidates.
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12
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Angula KT, Legoabe LJ, Jordaan A, Warner DF, Beteck RM. Investigation of quinolone-tethered aminoguanidine as novel antibacterial agents. Arch Pharm (Weinheim) 2022; 355:e2200172. [PMID: 35674486 DOI: 10.1002/ardp.202200172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/10/2022] [Accepted: 05/19/2022] [Indexed: 11/05/2022]
Abstract
A recent study identified quinolone-based thiosemicarbazone with an MIC90 value of 2 µM against Mycobacterium tuberculosis (Mtb). Herein, we report further optimization of the previous hit, which led to the discovery of quinolone-tethered aminoguanidine molecules with generally good antitubercular activity. Compounds 7f and 8e emerged as the hits of the series with submicromolar antitubercular activity, exhibiting MIC90 values of 0.49/0.90 and 0.49/0.60 µM, respectively, in the 7H9 CAS GLU Tx medium. This shows a fivefold increase in antitubercular activity compared to the previous study. Target compounds were also screened against ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens. However, the series generally exhibited poor antibacterial activities, with only compounds 8d and 8e demonstrating >50% growth inhibition of Staphylococcus aureus and Pseudomonas aeruginosa at 32 µg/ml. The compounds displayed selective antitubercular activity as they showed no cytotoxicity effects against two noncancerous human cell lines. In silico studies predict 7f to have good solubility, no inhibitory effect on cytochrome P450 isoenzymes, and to be a non-pan-assay interfering compound.
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Affiliation(s)
- Klaudia T Angula
- Department of Pharmaceutical Chemistry, Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| | - Lesetja J Legoabe
- Department of Pharmaceutical Chemistry, Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| | - Audrey Jordaan
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology, University of Cape Town, Observatory, South Africa
| | - Digby F Warner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology, University of Cape Town, Observatory, South Africa.,Molecular Mycobacteriology Research Unit, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, South Africa.,Department of Pathology, Wellcome Centre for Infectious Diseases Research in Africa (CIDRI-Africa), Faculty of Health Sciences, University of Cape Town, Rondebosch, South Africa
| | - Richard M Beteck
- Department of Pharmaceutical Chemistry, Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
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Naclerio GA, Onyedibe KI, Karanja CW, Aryal UK, Sintim HO. Comparative Studies to Uncover Mechanisms of Action of N-(1,3,4-Oxadiazol-2-yl)benzamide Containing Antibacterial Agents. ACS Infect Dis 2022; 8:865-877. [PMID: 35297603 PMCID: PMC9188027 DOI: 10.1021/acsinfecdis.1c00613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Drug-resistant bacterial pathogens still cause high levels of mortality annually despite the availability of many antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) is especially problematic, and the rise in resistance to front-line treatments like vancomycin and linezolid calls for new chemical modalities to treat chronic and relapsing MRSA infections. Halogenated N-(1,3,4-oxadiazol-2-yl)benzamides are an interesting class of antimicrobial agents, which have been described by multiple groups to be effective against different bacterial pathogens. The modes of action of a few N-(1,3,4-oxadiazol-2-yl)benzamides have been elucidated. For example, oxadiazoles KKL-35 and MBX-4132 have been described as inhibitors of trans-translation (a ribosome rescue pathway), while HSGN-94 was shown to inhibit lipoteichoic acid (LTA). However, other similarly halogenated N-(1,3,4-oxadiazol-2-yl)benzamides neither inhibit trans-translation nor LTA biosynthesis but are potent antimicrobial agents. For example, HSGN-220, -218, and -144 are N-(1,3,4-oxadiazol-2-yl)benzamides that are modified with OCF3, SCF3, or SF5 and have remarkable minimum inhibitory concentrations ranging from 1 to 0.06 μg/mL against MRSA clinical isolates and show a low propensity to develop resistance to MRSA over 30 days. The mechanism of action of these highly potent oxadiazoles is however unknown. To provide insights into how these halogenated N-(1,3,4-oxadiazol-2-yl)benzamides inhibit bacterial growth, we performed global proteomics and RNA expression analysis of some essential genes of S. aureus treated with HSGN-220, -218, and -144. These studies revealed that the oxadiazoles HSGN-220, -218, and -144 are multitargeting antibiotics that regulate menaquinone biosynthesis and other essential proteins like DnaX, Pol IIIC, BirA, LexA, and DnaC. In addition, these halogenated N-(1,3,4-oxadiazol-2-yl)benzamides were able to depolarize bacterial membranes and regulate siderophore biosynthesis and heme regulation. Iron starvation appears to be part of the mechanism of action that led to bacterial killing. This study demonstrates that N-(1,3,4-oxadiazol-2-yl)benzamides are indeed privileged scaffolds for the development of antibacterial agents and that subtle modifications lead to changes to the mechanism of action.
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Affiliation(s)
- George A. Naclerio
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, Indiana 47907, United States
| | - Kenneth I. Onyedibe
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Institute for Inflammation, Immunology, and Infectious Diseases, West Lafayette, Indiana 47907, United States
| | - Caroline W. Karanja
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, Indiana 47907, United States
| | - Uma K. Aryal
- Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Proteomics Facility, Bindley Bioscience Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Herman O. Sintim
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Institute for Inflammation, Immunology, and Infectious Diseases, West Lafayette, Indiana 47907, United States
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14
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Garey KW, McPherson J, Dinh AQ, Hu C, Jo J, Wang W, Lancaster CK, Gonzales-Luna AJ, Loveall C, Begum K, Alam MJ, Silverman MH, Hanson B. Efficacy, Safety, Pharmacokinetics, and Microbiome Changes of Ibezapolstat in Adults with Clostridioides difficile Infection: A Phase 2a Multicenter Clinical Trial. Clin Infect Dis 2022; 75:1164-1170. [PMID: 35134880 PMCID: PMC9525077 DOI: 10.1093/cid/ciac096] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Indexed: 12/17/2022] Open
Abstract
Background This study was the first human validation of the gram-positive bacterial DNA polymerase IIIC target in patients with Clostridioides difficile infection. The primary objectives were to assess clinical cure rates and adverse events (AEs). Secondary objectives were to evaluate plasma/fecal pharmacokinetics, microbiologic eradication, microbiome and bile acid effects, and sustained clinical cure (SCC) with ibezapolstat. Methods This single-arm, open-label, phase 2a study enrolled adults with C. difficile infection at 4 US centers. Patients received ibezapolstat 450 mg orally every 12 hours for 10 days and followed for an additional 28 days to assess study objectives. Results Ten patients with a mean (standard deviation [SD]) age of 49 [15] years were enrolled. Seven AEs were reported classified as mild-moderate. Plasma levels of ibezapolstat ranged from 233 to 578 ng/mL while mean (SD) fecal levels were 416 (494) µg/g stool by treatment day 3 and >1000 µg/g stool by days 8–10. A rapid increase in alpha diversity in the fecal microbiome was noted after starting ibezapolstat therapy, which was maintained after completion of therapy. A proportional decrease in Bacteroidetes phylum was observed (mean change [SD], −10.0% [4.8%]; P = .04) with a concomitantly increased proportion of Firmicutes phylum (+14.7% [5.4%]; P = .009). Compared with baseline, total primary bile acids decreased by a mean (SD) of 40.1 (9.6) ng/mg stool during therapy (P < .001) and 40.5 (14.1) ng/mg stool after completion of therapy (P = .007). Rates of both initial clinical cure and SCC at 28 days were 100% (10 of 10 patients). Conclusions In this phase 2a study, 10 of 10 patients achieved SCC, demonstrated favorable pharmacokinetics, minimal AEs, and beneficial microbiome and bile acids results. These results support continued clinical development.
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Affiliation(s)
- Kevin W Garey
- University of Houston College of Pharmacy, Houston, TX USA.,University of Texas School of Public Health, Houston, TX USA
| | | | - An Q Dinh
- University of Texas School of Public Health, Houston, TX USA
| | - Chenlin Hu
- University of Houston College of Pharmacy, Houston, TX USA
| | - Jinhee Jo
- University of Houston College of Pharmacy, Houston, TX USA
| | - Weiqun Wang
- University of Houston College of Pharmacy, Houston, TX USA
| | | | | | | | | | | | | | - Blake Hanson
- University of Texas School of Public Health, Houston, TX USA
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15
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Cui X, Lü Y, Yue C. Development and Research Progress of Anti-Drug Resistant Bacteria Drugs. Infect Drug Resist 2022; 14:5575-5593. [PMID: 34992385 PMCID: PMC8711564 DOI: 10.2147/idr.s338987] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/12/2021] [Indexed: 01/10/2023] Open
Abstract
Bacterial resistance has become increasingly serious because of the widespread use and abuse of antibiotics. In particular, the emergence of multidrug-resistant bacteria has posed a serious threat to human public health and attracted the attention of the World Health Organization (WHO) and the governments of various countries. Therefore, the establishment of measures against bacterial resistance and the discovery of new antibacterial drugs are increasingly urgent to better contain the emergence of bacterial resistance and provide a reference for the development of new antibacterial drugs. In this review, we discuss some antibiotic drugs that have been approved for clinical use and a partial summary of the meaningful research results of anti-drug resistant bacterial drugs in different fields, including the antibiotic drugs approved by the FDA from 2015 to 2020, the potential drugs against drug-resistant bacteria, the new molecules synthesized by chemical modification, combination therapy, drug repurposing, immunotherapy and other therapies.
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Affiliation(s)
- Xiangyi Cui
- Key Laboratory of Microbial Drugs Innovation and Transformation of Yan'an, School of Basic Medicine, Yan'an University, Yan'an, 716000, Shaanxi, People's Republic of China
| | - Yuhong Lü
- Key Laboratory of Microbial Drugs Innovation and Transformation of Yan'an, School of Basic Medicine, Yan'an University, Yan'an, 716000, Shaanxi, People's Republic of China.,Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, Yan'an University, Yan'an, 716000, Shaanxi, People's Republic of China
| | - Changwu Yue
- Key Laboratory of Microbial Drugs Innovation and Transformation of Yan'an, School of Basic Medicine, Yan'an University, Yan'an, 716000, Shaanxi, People's Republic of China.,Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, Yan'an University, Yan'an, 716000, Shaanxi, People's Republic of China
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16
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Abd El-Hameed RH, Sayed AI, Mahmoud Ali S, Mosa MA, Khoder ZM, Fatahala SS. Synthesis of novel pyrroles and fused pyrroles as antifungal and antibacterial agents. J Enzyme Inhib Med Chem 2021; 36:2183-2198. [PMID: 34602000 PMCID: PMC8491725 DOI: 10.1080/14756366.2021.1984904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 09/12/2021] [Accepted: 09/20/2021] [Indexed: 11/22/2022] Open
Abstract
Pyrroles and its fused forms possess antimicrobial activities, they can easily interact with biomolecules of living systems. A series of substituted pyrroles, and its fused pyrimidines and triazines forms have been synthesised, all newly synthesised compound structures were confirmed by spectroscopic analysis. Generally, the compounds inhibited growth of some important human pathogens, the best effect was given by: 2a, 3c, 4d on Gram-positive bacteria and was higher on yeast (C. albicans), by 5c on Gram-negative bacteria and by 5a then 3c on filamentous fungi (A. fumigatus and F. oxysporum). Such results present good antibacterial and antifungal potential candidates to help overcome the global problem of antibiotic resistance and opportunistic infections outbreak. Compound 3c gave the best anti-phytopathogenic effect at a 50-fold lower concentration than Kocide 2000, introducing a safe commercial candidate for agricultural use. The effect of the compounds on DNA was monitored to detect the mode of action.
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Affiliation(s)
- Rania Helmy Abd El-Hameed
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Helwan University, Helwan, Cairo, Egypt
| | - Amira Ibrahim Sayed
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Helwan University, Helwan, Cairo, Egypt
| | - Shima Mahmoud Ali
- Department of Chemistry, The state University of New York at Buffalo, New York, NY, USA
| | - Mohamed A. Mosa
- Microbiology and Immunology Department, Faculty of Pharmacy, Helwan University, Helwan, Cairo, Egypt
| | - Zainab M. Khoder
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Helwan University, Helwan, Cairo, Egypt
- Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
| | - Samar Said Fatahala
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Helwan University, Helwan, Cairo, Egypt
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17
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Gonzales-Luna AJ, Carlson TJ, Garey KW. Antibiotic Therapies for Clostridioides difficile Infection in Children. J Pediatric Infect Dis Soc 2021; 10:S52-S57. [PMID: 34791393 DOI: 10.1093/jpids/piab059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
While rates of Clostridioides difficile infection (CDI) are increasing among children in the United States, studies assessing CDI treatment in children are severely lacking. Thus, treatment guidelines have historically relied on evidence from limited observational data in children and randomized controlled trials (RCTs) conducted in adults to form recommendations. Currently, the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) recommend metronidazole and/or vancomycin for pediatric CDI depending on disease severity. Recently however, the first and only RCT of CDI treatment in children demonstrated fidaxomicin to be non-inferior to vancomycin, proving its safety and efficacy in this population. Additionally, observational data published since the IDSA/SHEA guidelines were released suggest metronidazole has lower rates of clinical improvement when compared to vancomycin in hospitalized children with non-severe CDI. Given these recent publications, fidaxomicin and vancomycin, instead of metronidazole, appear to be more appropriate, evidence-based options for the treatment of CDI in children.
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Affiliation(s)
- Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, 4849 Calhoun Road, Houston, Texas, 77204, USA
| | - Travis J Carlson
- Department of Clinical Sciences, High Point University Fred Wilson School of Pharmacy, One University Parkway, High Point, North Carolina, 27268, USA
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, 4849 Calhoun Road, Houston, Texas, 77204, USA
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18
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Sanad SM, Mekky AE. New pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(3H)-one hybrids linked to arene units: synthesis of potential MRSA, VRE, and COX-2 inhibitors. CAN J CHEM 2021. [DOI: 10.1139/cjc-2021-0121] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the current study, we reported the tandem synthesis of two series of arene-linked pyrimidinone hybrids with related fused thieno[2,3-b]pyridine moiety. The target hybrids were prepared, in moderate to excellent yields, by the reaction of a ternary mixture of the appropriate of 3-aminothieno[2,3-b]pyridine-2-carboxylate, DMF-DMA, and a series of aryl amines in dioxane at 110 °C for 8 h. The antibacterial activity of the new hybrids was estimated against six susceptible ATCC strains. Hybrids 5g and 7g, linked to a sulfonamide unit, showed the best efficacy against S. aureus and E. faecalis strains with minimum inhibitory concentration (MIC) values of 1.7–1.8 μM, which exceed ciprofloxacin. Furthermore, some of new hybrids were examined as potential inhibitors of four different MRSA and VRE strains. Hybrids 5g and 7g demonstrated more potent efficacy than linezolid against MRSA strains with MIC values of 3.6/3.4 and 1.8/1.7 μM against ATCC:33591 and ATCC:43300 strains, respectively. The prior hybrids displayed a comparable efficacy with linezolid against VRE strains with MIC values of 7.3/6.9 and 3.6/3.4 μM against ATCC:51299 and ATCC:51575 strains, respectively. Additionally, some of the new hybrids were examined as potential COX-2 inhibitors using the reference celecoxib (IC50 of 0.117 µM). Hybrid 7g revealed more potent inhibitory efficacy than celecoxib with IC50 of 0.112 µM, whereas hybrid 5g showed almost inhibitory activity equivalent to celecoxib with IC50 of 0.121 µM. Molecular docking was performed to predict the possible binding interactions between hybrids 5g and 7g with the target COX-2 enzyme.
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Affiliation(s)
- Sherif M.H. Sanad
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt
| | - Ahmed E.M. Mekky
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt
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19
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Garey KW, Begum K, Lancaster C, Gonzales-Luna A, Bui D, Mercier J, Seng Yue C, Ducharme MP, Hu M, Vince B, Silverman MH, Alam MJ, Kankam M. A randomized, double-blind, placebo-controlled, single and multiple ascending dose Phase 1 study to determine the safety, pharmacokinetics and food and faecal microbiome effects of ibezapolstat administered orally to healthy subjects. J Antimicrob Chemother 2021; 75:3635-3643. [PMID: 32892222 PMCID: PMC7662179 DOI: 10.1093/jac/dkaa364] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 07/17/2020] [Indexed: 01/07/2023] Open
Abstract
Background Clostridioides difficile infection is the most common cause of healthcare-associated infections in the USA, with limited treatment options. Ibezapolstat is a novel DNA polymerase IIIC inhibitor with in vitro activity against C. difficile. Objectives and methods Randomized, double-blind, placebo-controlled study to assess the safety, tolerability and pharmacokinetics of ibezapolstat in healthy volunteers. Microbiome changes associated with ibezapolstat were compared with vancomycin over a 10 day course using shotgun metagenomics. Results A total of 62 subjects aged 31 ± 7 years (45% female; average BMI: 25 ± 3 kg/m2) were randomized. Ibezapolstat was well tolerated with a safety signal similar to placebo. Ibezapolstat had minimal systemic absorption with the majority of plasma concentrations less than 1 µg/mL. In the multiday, ascending dose study, ibezapolstat concentrations of 2000 µg/g of stool were observed by Day 2 and for the remainder of the dosing time period. In the multiday, multiple-dose arm, baseline microbiota was comparable between subjects that received ibezapolstat compared with vancomycin. At Day 10 of dosing, differential abundance analysis and β-diversity demonstrated a distinct difference between the microbiome in subjects given vancomycin compared with either dose of ibezapolstat (P = 0.006). α-Diversity changes were characterized as an increase in the Actinobacteria phylum in subjects that received ibezapolstat and an increase in Proteobacteria in subjects given vancomycin. Conclusions Ibezapolstat was shown to be safe and well tolerated, with minimal systemic exposure, high stool concentrations and a distinct microbiome profile compared with oral vancomycin. These results support further clinical development of ibezapolstat for patients with C. difficile infection.
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Affiliation(s)
| | | | | | | | - Dinh Bui
- University of Houston, Houston, TX, USA
| | - Julie Mercier
- Altasciences Clinical Kansas, Overland Park, KS, USA
| | | | | | - Ming Hu
- University of Houston, Houston, TX, USA
| | - Bradley Vince
- Altasciences Clinical Kansas, Overland Park, KS, USA
| | | | | | - Martin Kankam
- Altasciences Clinical Kansas, Overland Park, KS, USA
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20
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Chemical Classes Presenting Novel Antituberculosis Agents Currently in Different Phases of Drug Development: A 2010-2020 Review. PHARMACEUTICALS (BASEL, SWITZERLAND) 2021; 14:ph14050461. [PMID: 34068171 PMCID: PMC8152995 DOI: 10.3390/ph14050461] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/08/2021] [Accepted: 05/10/2021] [Indexed: 01/18/2023]
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is a curable airborne disease currently treated using a drug regimen consisting of four drugs. Global TB control has been a persistent challenge for many decades due to the emergence of drug-resistant Mtb strains. The duration and complexity of TB treatment are the main issues leading to treatment failures. Other challenges faced by currently deployed TB regimens include drug-drug interactions, miss-matched pharmacokinetics parameters of drugs in a regimen, and lack of activity against slow replicating sub-population. These challenges underpin the continuous search for novel TB drugs and treatment regimens. This review summarizes new TB drugs/drug candidates under development with emphasis on their chemical classes, biological targets, mode of resistance generation, and pharmacokinetic properties. As effective TB treatment requires a combination of drugs, the issue of drug-drug interaction is, therefore, of great concern; herein, we have compiled drug-drug interaction reports, as well as efficacy reports for drug combinations studies involving antitubercular agents in clinical development.
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21
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Tian T, Zhao J, Wang Y, Li B, Qiao L, Zhang K, Liu B. Transpeptidation-mediated single-particle imaging assay for sensitive and specific detection of sortase with dark-field optical microscopy. Biosens Bioelectron 2021; 178:113003. [PMID: 33486157 DOI: 10.1016/j.bios.2021.113003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 12/10/2020] [Accepted: 01/12/2021] [Indexed: 11/30/2022]
Abstract
Transpeptidation of surface proteins catalyzed by the transpeptidase sortase plays a critical role in the infection process of Gram-positive pathogen. Monitoring sortase activity and screening its inhibitors are of great significance to fundamental understanding of the infection mechanism and pharmaceutical development. Herein, we developed a digital single-particle imaging method to quantify sortase A (SrtA) activity based on transpeptidation-mediated assembly and enumeration of gold nanoparticles (GNPs). The assay utilizes two peptide stands, in which one has the SrtA recognition sequence LPXTG motif while the other carries an oligoglycine nucleophile at the one end and a biotin group at the other. The presence of SrtA enables the ligation of two peptides and allows for the immobilization of streptavidin-functionalized GNPs. Thus, SrtA activity can be quantified by imaging and enumeration of the surface-assembled GNPs at the single-particle level via dark-field microscopy. The single-particle method was highly sensitive to SrtA activity with a low detection limit of 7.9 pM and a wide linear dynamic range from 0.05 to 50 nM. Besides detection of SrtA in complex biological samples such as Gram-positive pathogen lysates, the proposed method was also successfully applied to estimate the half-maximal inhibitory concentration (IC50) values of SrtA inhibitors (curcumin, berberine hydrochloride and quercetin). The present method, combining single-GNP counting and dark-field imaging, provides a facile and novel analytical tool for SrtA activity and its inhibitor screening.
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Affiliation(s)
- Tongtong Tian
- Department of Chemistry, Shanghai Stomatological Hospital, State Key Laboratory of Molecular Engineering of Polymers and Institute of Biomedical Sciences, Fudan University, Shanghai, 200433, PR China
| | - Jinzhi Zhao
- Department of Chemistry, Shanghai Stomatological Hospital, State Key Laboratory of Molecular Engineering of Polymers and Institute of Biomedical Sciences, Fudan University, Shanghai, 200433, PR China
| | - Yuning Wang
- Department of Chemistry, Shanghai Stomatological Hospital, State Key Laboratory of Molecular Engineering of Polymers and Institute of Biomedical Sciences, Fudan University, Shanghai, 200433, PR China
| | - Binxiao Li
- Department of Chemistry, Shanghai Stomatological Hospital, State Key Laboratory of Molecular Engineering of Polymers and Institute of Biomedical Sciences, Fudan University, Shanghai, 200433, PR China
| | - Liang Qiao
- Department of Chemistry, Shanghai Stomatological Hospital, State Key Laboratory of Molecular Engineering of Polymers and Institute of Biomedical Sciences, Fudan University, Shanghai, 200433, PR China
| | - Kun Zhang
- Department of Neurosurgery, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 200062, PR China.
| | - Baohong Liu
- Department of Chemistry, Shanghai Stomatological Hospital, State Key Laboratory of Molecular Engineering of Polymers and Institute of Biomedical Sciences, Fudan University, Shanghai, 200433, PR China.
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22
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Novel Antibiotics Targeting Bacterial Replicative DNA Polymerases. Antibiotics (Basel) 2020; 9:antibiotics9110776. [PMID: 33158178 PMCID: PMC7694242 DOI: 10.3390/antibiotics9110776] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/31/2020] [Accepted: 11/02/2020] [Indexed: 12/15/2022] Open
Abstract
Multidrug resistance is a worldwide problem that is an increasing threat to global health. Therefore, the development of new antibiotics that inhibit novel targets is of great urgency. Some of the most successful antibiotics inhibit RNA transcription, RNA translation, and DNA replication. Transcription and translation are inhibited by directly targeting the RNA polymerase or ribosome, respectively. DNA replication, in contrast, is inhibited indirectly through targeting of DNA gyrases, and there are currently no antibiotics that inhibit DNA replication by directly targeting the replisome. This contrasts with antiviral therapies where the viral replicases are extensively targeted. In the last two decades there has been a steady increase in the number of compounds that target the bacterial replisome. In particular a variety of inhibitors of the bacterial replicative polymerases PolC and DnaE have been described, with one of the DNA polymerase inhibitors entering clinical trials for the first time. In this review we will discuss past and current work on inhibition of DNA replication, and the potential of bacterial DNA polymerase inhibitors in particular as attractive targets for a new generation of antibiotics.
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23
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Oliveira Paiva AM, van Eijk E, Friggen AH, Weigel C, Smits WK. Identification of the Unwinding Region in the Clostridioides difficile Chromosomal Origin of Replication. Front Microbiol 2020; 11:581401. [PMID: 33133049 PMCID: PMC7561715 DOI: 10.3389/fmicb.2020.581401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022] Open
Abstract
Faithful DNA replication is crucial for viability of cells across all kingdoms. Targeting DNA replication is a viable strategy for inhibition of bacterial pathogens. Clostridioides difficile is an important enteropathogen that causes potentially fatal intestinal inflammation. Knowledge about DNA replication in this organism is limited and no data is available on the very first steps of DNA replication. Here, we use a combination of in silico predictions and in vitro experiments to demonstrate that C. difficile employs a bipartite origin of replication that shows DnaA-dependent melting at oriC2, located in the dnaA-dnaN intergenic region. Analysis of putative origins of replication in different clostridia suggests that the main features of the origin architecture are conserved. This study is the first to characterize aspects of the origin region of C. difficile and contributes to our understanding of the initiation of DNA replication in clostridia.
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Affiliation(s)
- Ana M Oliveira Paiva
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands.,Centre for Microbial Cell Biology, Leiden, Netherlands
| | - Erika van Eijk
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands
| | - Annemieke H Friggen
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands
| | - Christoph Weigel
- Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Wiep Klaas Smits
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands.,Centre for Microbial Cell Biology, Leiden, Netherlands
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24
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Kullar R, Tran MCN, Goldstein EJC. Investigational Treatment Agents for Recurrent Clostridioides difficile Infection (rCDI). J Exp Pharmacol 2020; 12:371-384. [PMID: 33116952 PMCID: PMC7553590 DOI: 10.2147/jep.s242959] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/13/2020] [Indexed: 11/23/2022] Open
Abstract
Clostridioides difficile infection (CDI) is a major cause of nosocomial diarrhea that is deemed a global health threat. C. difficile strain BI/NAP1/027 has contributed to the increase in the mortality, severity of CDI outbreaks and recurrence rates (rCDI). Updated CDI treatment guidelines suggest vancomycin and fidaxomicin as initial first-line therapies that have initial clinical cure rates of over 80%. Unacceptably high recurrence rates of 15–30% in patients for the first episode and 40% for the second recurrent episode are reported. Alternative treatments for rCDI include fecal microbiota transplant and a human monoclonal antibody, bezlotoxumab, that can be used in patients with high risk of rCDI. Various emerging potential therapies with narrow spectrum of activity and little systemic absorption that are in development include 1) Ibezapolstat (formerly ACX-362E), MGB-BP-3, and DS-2969b-targeting bacterial DNA replication, 2) CRS3213 (REP3123)-inhibiting toxin production and spore formation, 3) ramizol and ramoplanin-affecting bacterial cell wall, 4) LFF-571-blocking protein synthesis, 5) Alanyl-L-Glutamine (alanylglutamine)-inhibiting damage caused by C. difficile by protecting intestinal mucosa, and 6) DNV3837 (MCB3681)-prodrug consisting of an oxazolidinone–quinolone combination that converts to the active form DNV3681 that has activity in vitro against C. difficile. This review article provides an overview of these developing drugs that can have potential role in the treatment of rCDI and in lowering recurrence rates.
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Affiliation(s)
| | - Mai-Chi N Tran
- Pharmacy Department, Keck Medical Center of USC, Los Angeles, CA, USA.,Clinica Juan Pablo Medical Group, Los Angeles, CA, USA
| | - Ellie J C Goldstein
- R.M. Alden Research Laboratory, Santa Monica, CA, USA.,David Geffen School of Medicine, Los Angeles, CA, USA
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25
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Murray B, Wolfe C, Marra A, Pillar C, Shinabarger D. In vitro activity of the novel antibacterial agent ibezapolstat (ACX-362E) against Clostridioides difficile. J Antimicrob Chemother 2020; 75:2149-2155. [PMID: 32285102 DOI: 10.1093/jac/dkaa134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 03/10/2020] [Accepted: 03/14/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Ibezapolstat (ACX-362E) is the first DNA polymerase IIIC inhibitor undergoing clinical development for the oral treatment of Clostridioides difficile infection (CDI). METHODS In this study, the in vitro activity of ibezapolstat was evaluated against a panel of 104 isolates of C. difficile, including those with characterized ribotypes (e.g. 027 and 078) and those producing toxin A or B and was shown to have similar activity to those of comparators against these strains. RESULTS The overall MIC50/90 (mg/L) for ibezapolstat against evaluated C. difficile was 2/4, compared with 0.5/4 for metronidazole, 1/4 for vancomycin and 0.5/2 for fidaxomicin. In addition, the bactericidal activity of ibezapolstat was evaluated against actively growing C. difficile by determining the MBC against three C. difficile isolates. Time-kill kinetic assays were additionally performed against the three C. difficile isolates, with metronidazole and vancomycin as comparators. CONCLUSIONS The killing of C. difficile by ibezapolstat was observed to occur at concentrations similar to its MIC, as demonstrated by MBC:MIC ratios and reflected in time-kill kinetic assays. This activity highlights the therapeutic potential of ibezapolstat for the treatment of CDI.
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Affiliation(s)
- Beverly Murray
- Micromyx, Inc, 4717 Campus Drive, Kalamazoo, MI 49008, USA
| | | | - Andrea Marra
- Micromyx, Inc, 4717 Campus Drive, Kalamazoo, MI 49008, USA
| | - Chris Pillar
- Micromyx, Inc, 4717 Campus Drive, Kalamazoo, MI 49008, USA
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26
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Antibiotic Treatment Pipeline for Clostridioides difficile Infection (CDI): A Wide Array of Narrow-Spectrum Agents. Curr Infect Dis Rep 2020. [DOI: 10.1007/s11908-020-00730-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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27
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Breijyeh Z, Jubeh B, Karaman R. Resistance of Gram-Negative Bacteria to Current Antibacterial Agents and Approaches to Resolve It. Molecules 2020; 25:E1340. [PMID: 32187986 PMCID: PMC7144564 DOI: 10.3390/molecules25061340] [Citation(s) in RCA: 511] [Impact Index Per Article: 127.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/12/2020] [Accepted: 03/12/2020] [Indexed: 12/18/2022] Open
Abstract
Antimicrobial resistance represents an enormous global health crisis and one of the most serious threats humans face today. Some bacterial strains have acquired resistance to nearly all antibiotics. Therefore, new antibacterial agents are crucially needed to overcome resistant bacteria. In 2017, the World Health Organization (WHO) has published a list of antibiotic-resistant priority pathogens, pathogens which present a great threat to humans and to which new antibiotics are urgently needed the list is categorized according to the urgency of need for new antibiotics as critical, high, and medium priority, in order to guide and promote research and development of new antibiotics. The majority of the WHO list is Gram-negative bacterial pathogens. Due to their distinctive structure, Gram-negative bacteria are more resistant than Gram-positive bacteria, and cause significant morbidity and mortality worldwide. Several strategies have been reported to fight and control resistant Gram-negative bacteria, like the development of antimicrobial auxiliary agents, structural modification of existing antibiotics, and research into and the study of chemical structures with new mechanisms of action and novel targets that resistant bacteria are sensitive to. Research efforts have been made to meet the urgent need for new treatments; some have succeeded to yield activity against resistant Gram-negative bacteria by deactivating the mechanism of resistance, like the action of the β-lactamase Inhibitor antibiotic adjuvants. Another promising trend was by referring to nature to develop naturally derived agents with antibacterial activity on novel targets, agents such as bacteriophages, DCAP(2-((3-(3,6-dichloro-9H-carbazol-9-yl)-2-hydroxypropyl)amino)-2(hydroxymethyl)propane1,3-diol, Odilorhabdins (ODLs), peptidic benzimidazoles, quorum sensing (QS) inhibitors, and metal-based antibacterial agents.
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Affiliation(s)
| | | | - Rafik Karaman
- Department of Bioorganic & Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Quds University, Jerusalem P.O. Box 20002, Palestine; (Z.B.); (B.J.)
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Antibiotics in the clinical pipeline in October 2019. J Antibiot (Tokyo) 2020; 73:329-364. [PMID: 32152527 PMCID: PMC7223789 DOI: 10.1038/s41429-020-0291-8] [Citation(s) in RCA: 167] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/30/2020] [Accepted: 01/30/2020] [Indexed: 12/27/2022]
Abstract
The development of new and effective antibacterial drugs to treat multi-drug resistant (MDR) bacteria, especially Gram-negative (G−ve) pathogens, is acknowledged as one of the world’s most pressing health issues; however, the discovery and development of new, nontoxic antibacterials is not a straightforward scientific task, which is compounded by a challenging economic model. This review lists the antibacterials, β-lactamase/β-lactam inhibitor (BLI) combinations, and monoclonal antibodies (mAbs) first launched around the world since 2009 and details the seven new antibiotics and two new β-lactam/BLI combinations launched since 2016. The development status, mode of action, spectra of activity, lead source, and administration route for the 44 small molecule antibacterials, eight β-lactamase/BLI combinations, and one antibody drug conjugate (ADC) being evaluated in worldwide clinical trials at the end of October 2019 are described. Compounds discontinued from clinical development since 2016 and new antibacterial pharmacophores are also reviewed. There has been an increase in the number of early stage clinical candidates, which has been fueled by antibiotic-focused funding agencies; however, there is still a significant gap in the pipeline for the development of new antibacterials with activity against β-metallolactamases, orally administered with broad spectrum G−ve activity, and new treatments for MDR Acinetobacter and gonorrhea.
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