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Hong Y, Hu D, Verderosa AD, Qin J, Totsika M, Reeves PR. Repeat-Unit Elongations To Produce Bacterial Complex Long Polysaccharide Chains, an O-Antigen Perspective. EcoSal Plus 2023; 11:eesp00202022. [PMID: 36622162 DOI: 10.1128/ecosalplus.esp-0020-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 12/02/2022] [Indexed: 01/10/2023]
Abstract
The O-antigen, a long polysaccharide that constitutes the distal part of the outer membrane-anchored lipopolysaccharide, is one of the critical components in the protective outer membrane of Gram-negative bacteria. Most species produce one of the structurally diverse O-antigens, with nearly all the polysaccharide components having complex structures made by the Wzx/Wzy pathway. This pathway produces repeat-units of mostly 3-8 sugars on the cytosolic face of the cytoplasmic membrane that is translocated by Wzx flippase to the periplasmic face and polymerized by Wzy polymerase to give long-chain polysaccharides. The Wzy polymerase is a highly diverse integral membrane protein typically containing 10-14 transmembrane segments. Biochemical evidence confirmed that Wzy polymerase is the sole driver of polymerization, and recent progress also began to demystify its interacting partner, Wzz, shedding some light to speculate how the proteins may operate together during polysaccharide biogenesis. However, our knowledge of how the highly variable Wzy proteins work as part of the O-antigen processing machinery remains poor. Here, we discuss the progress to the current understanding of repeat-unit polymerization and propose an updated model to explain the formation of additional short chain O-antigen polymers found in the lipopolysaccharide of diverse Gram-negative species and their importance in the biosynthetic process.
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Affiliation(s)
- Yaoqin Hong
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Dalong Hu
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Anthony D Verderosa
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Jilong Qin
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Makrina Totsika
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Peter R Reeves
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
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2
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Gavin NC, Wignall E, Marsh N, Marquart L, Dobeli KL, O'Brien C, Verderosa AD, Totsika M, Keogh S. Perforated intravenous catheter design is acceptable for the administration of contrast-enhanced computed tomography administration in cancer patients: Results of a pilot randomised controlled trial. J Vasc Access 2023:11297298231171422. [PMID: 37264630 DOI: 10.1177/11297298231171422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
BACKGROUND Optimising first time success of peripheral intravenous catheter (PIVC) insertion and reducing intravenous (IV) complications in cancer patients undergoing contrast-enhanced computed tomography (CT) is vital to ensure vascular access preservation and diagnostic accuracy. The aim of this study was to test the feasibility of a randomised controlled trial (RCT) evaluating a novel perforated PIVC compared to a standard PIVC. METHODS A single centre, parallel-group, pilot RCT was conducted between March and May 2020. Adult participants diagnosed with cancer were randomised to a non-perforated PIVC (standard care) or a PIVC with a novel perforated design (intervention) for the administration of IV contrast. There were two primary outcomes: (1) feasibility of an adequately powered RCT with pre-established criteria; and (2) all-cause PIVC failure. Secondary outcomes included: first insertion success, modes of PIVC failure, dwell time, contrast injection parameters (volume and injection rate), contrast enhancement, radiographer satisfaction and adverse events. RESULTS Feasibility outcomes were met, except for eligibility (⩾90%) and recruitment (⩾90%). In total, 166 participants were screened, 128 (77%) were eligible and of these 101/128 (79%) were randomised; 50 to standard care and 51 to intervention. First time insertion rate was 94% (47/50) in standard care and 90% (46/50) in intervention. The median dwell time was 37 minutes (interquartile range (IQR): 25-55) in standard care and 35 minutes (IQR: 25-60) in the intervention group. There was one PIVC failure, a contrast media extravasation, in the intervention group (1/51; 2%). The desired contrast injection rate was not achieved in 4/101 (4%) of participants; two from each group. Radiographers were satisfied with the contrast flow rate. CONCLUSIONS This pilot RCT suggests perforated PIVCs provide expected flow rate, with no evidence of differences in contrast enhancement to non-perforated PIVCs. The feasibility of conducting a larger powered RCT was demonstrated.
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Affiliation(s)
- Nicole C Gavin
- School of Nursing and Centre for Healthcare Transformation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- Cancer Care Services, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
- Alliance for Vascular Access Teaching and Research (AVATAR), School of Pharmacy and Medical Sciences, Griffith University, Nathan, QLD, Australia
| | - Elizabeth Wignall
- Department of Medical Imaging, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Nicole Marsh
- School of Nursing and Centre for Healthcare Transformation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- Alliance for Vascular Access Teaching and Research (AVATAR), School of Pharmacy and Medical Sciences, Griffith University, Nathan, QLD, Australia
- Nursing and Midwifery Research Centre, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Louise Marquart
- School of Public Health, University of Queensland, Herston, QLD, Australia
- Queensland Institute of Medical Research Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Karen L Dobeli
- Department of Medical Imaging, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Catherine O'Brien
- Department of Medical Imaging, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
- Nursing and Midwifery Research Centre, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Anthony D Verderosa
- School of Biomedical Sciences and Centre for Immunology and Infection Control, Queensland University of Technology, Kelvin Grove, QLD, Australia
| | - Makrina Totsika
- School of Biomedical Sciences and Centre for Immunology and Infection Control, Queensland University of Technology, Kelvin Grove, QLD, Australia
| | - Samantha Keogh
- School of Nursing and Centre for Healthcare Transformation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- Alliance for Vascular Access Teaching and Research (AVATAR), School of Pharmacy and Medical Sciences, Griffith University, Nathan, QLD, Australia
- Nursing and Midwifery Research Centre, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
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3
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Rayner B, Verderosa AD, Ferro V, Blaskovich MAT. Siderophore conjugates to combat antibiotic-resistant bacteria. RSC Med Chem 2023; 14:800-822. [PMID: 37252105 PMCID: PMC10211321 DOI: 10.1039/d2md00465h] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 02/21/2023] [Indexed: 10/31/2023] Open
Abstract
Antimicrobial resistance (AMR) is a global threat to society due to the increasing emergence of multi-drug resistant bacteria that are not susceptible to our last line of defence antibiotics. Exacerbating this issue is a severe gap in antibiotic development, with no new clinically relevant classes of antibiotics developed in the last two decades. The combination of the rapidly increasing emergence of resistance and scarcity of new antibiotics in the clinical pipeline means there is an urgent need for new efficacious treatment strategies. One promising solution, known as the 'Trojan horse' approach, hijacks the iron transport system of bacteria to deliver antibiotics directly into cells - effectively tricking bacteria into killing themselves. This transport system uses natively produced siderophores, which are small molecules with a high affinity for iron. By linking antibiotics to siderophores, to make siderophore antibiotic conjugates, the activity of existing antibiotics can potentially be reinvigorated. The success of this strategy was recently exemplified with the clinical release of cefiderocol, a cephalosporin-siderophore conjugate with potent antibacterial activity against carbapenem-resistant and multi-drug resistant Gram-negative bacilli. This review discusses the recent advancements in siderophore antibiotic conjugates and the challenges associated with the design of these compounds that need to be overcome to deliver more efficacious therapeutics. Potential strategies have also been suggested for new generations of siderophore-antibiotics with enhanced activity.
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Affiliation(s)
- Beth Rayner
- Centre for Superbug Solutions, Institute for Molecular Bioscience, University of Queensland Brisbane Queensland Australia
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
| | - Anthony D Verderosa
- Centre for Superbug Solutions, Institute for Molecular Bioscience, University of Queensland Brisbane Queensland Australia
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
| | - Vito Ferro
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, University of Queensland Brisbane Queensland Australia
- Australian Infectious Disease Research Centre, The University of Queensland Brisbane Queensland Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland Australia
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4
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Abstract
Bacteria, similar to most organisms, have a love-hate relationship with metals: a specific metal may be essential for survival yet toxic in certain forms and concentrations. Metal ions have a long history of antimicrobial activity and have received increasing attention in recent years owing to the rise of antimicrobial resistance. The search for antibacterial agents now encompasses metal ions, nanoparticles and metal complexes with antimicrobial activity ('metalloantibiotics'). Although yet to be advanced to the clinic, metalloantibiotics are a vast and underexplored group of compounds that could lead to a much-needed new class of antibiotics. This Review summarizes recent developments in this growing field, focusing on advances in the development of metalloantibiotics, in particular, those for which the mechanism of action has been investigated. We also provide an overview of alternative uses of metal complexes to combat bacterial infections, including antimicrobial photodynamic therapy and radionuclide diagnosis of bacterial infections.
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Affiliation(s)
- Angelo Frei
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
| | - Anthony D Verderosa
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Alysha G Elliott
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Johannes Zuegg
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Mark A T Blaskovich
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
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5
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Wang G, Qin J, Verderosa AD, Hor L, Santos-Martin C, Paxman JJ, Martin JL, Totsika M, Heras B. A Buried Water Network Modulates the Activity of the Escherichia coli Disulphide Catalyst DsbA. Antioxidants (Basel) 2023; 12:antiox12020380. [PMID: 36829940 PMCID: PMC9952396 DOI: 10.3390/antiox12020380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/27/2023] [Accepted: 02/01/2023] [Indexed: 02/08/2023] Open
Abstract
The formation of disulphide bonds is an essential step in the folding of many proteins that enter the secretory pathway; therefore, it is not surprising that eukaryotic and prokaryotic organisms have dedicated enzymatic systems to catalyse this process. In bacteria, one such enzyme is disulphide bond-forming protein A (DsbA), a thioredoxin-like thiol oxidase that catalyses the oxidative folding of proteins required for virulence and fitness. A large body of work on DsbA proteins, particularly Escherichia coli DsbA (EcDsbA), has demonstrated the key role that the Cys30-XX-Cys33 catalytic motif and its unique redox properties play in the thiol oxidase activity of this enzyme. Using mutational and functional analyses, here we identify that a set of charged residues, which form an acidic groove on the non-catalytic face of the enzyme, further modulate the activity of EcDsbA. Our high-resolution structures indicate that these residues form a water-mediated proton wire that can transfer protons from the bulk solvent to the active site. Our results support the view that proton shuffling may facilitate the stabilisation of the buried Cys33 thiolate formed during the redox reaction and promote the correct direction of the EcDsbA-substrate thiol-disulphide exchange. Comparison with other proteins of the same class and proteins of the thioredoxin-superfamily in general suggest that a proton relay system appears to be a conserved catalytic feature among this widespread superfamily of proteins. Furthermore, this study also indicates that the acidic groove of DsbA could be a promising allosteric site to develop novel DsbA inhibitors as antibacterial therapeutics.
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Affiliation(s)
- Geqing Wang
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Correspondence: (G.W.); (B.H.)
| | - Jilong Qin
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Anthony D. Verderosa
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Lilian Hor
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Carlos Santos-Martin
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Jason J. Paxman
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Jennifer L. Martin
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
| | - Makrina Totsika
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Begoña Heras
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Correspondence: (G.W.); (B.H.)
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6
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Blaskovich MAT, Verderosa AD. Use of Antiviral Agents and other Therapies for COVID-19. Semin Respir Crit Care Med 2023; 44:118-129. [PMID: 36646090 DOI: 10.1055/s-0042-1758837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic led to a remarkably rapid development of a range of effective prophylactic vaccines, including new technologies that had not previously been approved for human use. In contrast, the development of new small molecule antiviral therapeutics has taken years to produce the first approved drugs specifically targeting severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), with the intervening years filled with attempts to repurpose existing drugs and the development of biological therapeutics. This review will discuss the reasons behind this variation in timescale and provide a survey of the many new treatments that are progressing through the clinical pipeline.
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Affiliation(s)
- Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Anthony D Verderosa
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
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7
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Hawas S, Verderosa AD, Totsika M. Combination Therapies for Biofilm Inhibition and Eradication: A Comparative Review of Laboratory and Preclinical Studies. Front Cell Infect Microbiol 2022; 12:850030. [PMID: 35281447 PMCID: PMC8915430 DOI: 10.3389/fcimb.2022.850030] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/04/2022] [Indexed: 12/26/2022] Open
Abstract
Microbial biofilms are becoming increasingly difficult to treat in the medical setting due to their intrinsic resistance to antibiotics. To combat this, several biofilm dispersal agents are currently being developed as treatments for biofilm infections. Combining biofilm dispersal agents with antibiotics is emerging as a promising strategy to simultaneously disperse and eradicate biofilms or, in some cases, even inhibit biofilm formation. Here we review studies that have investigated the anti-biofilm activity of some well-studied biofilm dispersal agents (e.g., quorum sensing inhibitors, nitric oxide/nitroxides, antimicrobial peptides/amino acids) in combination with antibiotics from various classes. This review aims to directly compare the efficacy of different combination strategies against microbial biofilms and highlight synergistic treatments that warrant further investigation. By comparing across studies that use different measures of efficacy, we can conclude that treating biofilms in vitro and, in some limited cases in vivo, with a combination of an anti-biofilm agent and an antibiotic, appears overall more effective than treating with either compound alone. The review identifies the most promising combination therapies currently under development as biofilm inhibition and eradication therapies.
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Affiliation(s)
- Sophia Hawas
- Centre for Immunology and Infection Control, Queensland University of Technology, Brisbane, QLD, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Anthony D. Verderosa
- Centre for Immunology and Infection Control, Queensland University of Technology, Brisbane, QLD, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Makrina Totsika
- Centre for Immunology and Infection Control, Queensland University of Technology, Brisbane, QLD, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- *Correspondence: Makrina Totsika,
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8
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Park JR, Verderosa AD, Totsika M, Hoogenboom R, Dargaville TR. Thermoresponsive Polymer-Antibiotic Conjugates Based on Gradient Copolymers of 2-Oxazoline and 2-Oxazine. Biomacromolecules 2021; 22:5185-5194. [PMID: 34726387 DOI: 10.1021/acs.biomac.1c01133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A polymer-antibiotic conjugate with thermoresponsive properties near body temperature is presented. The backbone polymer is a copolymer of 2-n-propyl-2-oxazine (PropOzi) and methoxycarbonylethyl-2-oxazoline (C2MestOx) which is conjugated with the broad-spectrum antibiotic, cefazolin, via modification of the methyl ester group of C2MestOx. The resulting polymer-antibiotic conjugate has a cloud point temperature near body temperature, meaning that it can form a homogenous solution if cooled, but when injected into a skin-mimic at 37 °C, it forms a drug depot precipitate. Cleavage of the ester linker leads to quantitative release of the pristine cefazolin (with some antibiotic degradation observed) and redissolution of the polymer. When Escherichia coli were treated with polymer-antibiotic conjugate total clearance is observed within 12 h. The power of this approach is the potential for localized antibiotic delivery, for example, at a specific tissue site or into infected phagocytic cells.
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Affiliation(s)
- Jong-Ryul Park
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Anthony D Verderosa
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland 4006, Australia
| | - Makrina Totsika
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland 4006, Australia
| | - Richard Hoogenboom
- Supramolecular Chemistry Group, Centre of Macromolecular Chemistry (CMaC), Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281 S4, Ghent B-9000, Belgium
| | - Tim R Dargaville
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland 4000, Australia
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9
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Subedi P, Paxman JJ, Wang G, Hor L, Hong Y, Verderosa AD, Whitten AE, Panjikar S, Santos-Martin CF, Martin JL, Totsika M, Heras B. Salmonella enterica BcfH Is a Trimeric Thioredoxin-Like Bifunctional Enzyme with Both Thiol Oxidase and Disulfide Isomerase Activities. Antioxid Redox Signal 2021; 35:21-39. [PMID: 33607928 DOI: 10.1089/ars.2020.8218] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Aims: Thioredoxin (TRX)-fold proteins are ubiquitous in nature. This redox scaffold has evolved to enable a variety of functions, including redox regulation, protein folding, and oxidative stress defense. In bacteria, the TRX-like disulfide bond (Dsb) family mediates the oxidative folding of multiple proteins required for fitness and pathogenic potential. Conventionally, Dsb proteins have specific redox functions with monomeric and dimeric Dsbs exclusively catalyzing thiol oxidation and disulfide isomerization, respectively. This contrasts with the eukaryotic disulfide forming machinery where the modular TRX protein disulfide isomerase (PDI) mediates thiol oxidation and disulfide reshuffling. In this study, we identified and structurally and biochemically characterized a novel Dsb-like protein from Salmonella enterica termed bovine colonization factor protein H (BcfH) and defined its role in virulence. Results: In the conserved bovine colonization factor (bcf) fimbrial operon, the Dsb-like enzyme BcfH forms a trimeric structure, exceptionally uncommon among the large and evolutionary conserved TRX superfamily. This protein also displays very unusual catalytic redox centers, including an unwound α-helix holding the redox active site and a trans-proline instead of the conserved cis-proline active site loop. Remarkably, BcfH displays both thiol oxidase and disulfide isomerase activities contributing to Salmonella fimbrial biogenesis. Innovation and Conclusion: Typically, oligomerization of bacterial Dsb proteins modulates their redox function, with monomeric and dimeric Dsbs mediating thiol oxidation and disulfide isomerization, respectively. This study demonstrates a further structural and functional malleability in the TRX-fold protein family. BcfH trimeric architecture and unconventional catalytic sites permit multiple redox functions emulating in bacteria the eukaryotic PDI dual oxidoreductase activity. Antioxid. Redox Signal. 35, 21-39.
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Affiliation(s)
- Pramod Subedi
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Jason J Paxman
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Geqing Wang
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Lilian Hor
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Yaoqin Hong
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Anthony D Verderosa
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Andrew E Whitten
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia
| | - Santosh Panjikar
- Macromolecular Crystallography, Australian Synchrotron, ANSTO, Clayton, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Carlos F Santos-Martin
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Jennifer L Martin
- Griffith Institute for Drug Discovery, Brisbane Innovation Park, Nathan, Australia.,Vice-Chancellor's Unit, University of Wollongong, Wollongong, Australia
| | - Makrina Totsika
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Begoña Heras
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
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10
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Dhouib R, Vagenas D, Hong Y, Verderosa AD, Martin JL, Heras B, Totsika M. Antivirulence DsbA inhibitors attenuate Salmonella enterica serovar Typhimurium fitness without detectable resistance. FASEB Bioadv 2021; 3:231-242. [PMID: 33842848 PMCID: PMC8019255 DOI: 10.1096/fba.2020-00100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 12/22/2020] [Accepted: 01/06/2021] [Indexed: 11/15/2022] Open
Abstract
Inhibition of the DiSulfide Bond (DSB) oxidative protein folding machinery, a major facilitator of virulence in Gram‐negative bacteria, represents a promising antivirulence strategy. We previously developed small molecule inhibitors of DsbA from Escherichia coli K‐12 (EcDsbA) and showed that they attenuate virulence of Gram‐negative pathogens by directly inhibiting multiple diverse DsbA homologues. Here we tested the evolutionary robustness of DsbA inhibitors as antivirulence antimicrobials against Salmonella enterica serovar Typhimurium under pathophysiological conditions in vitro. We show that phenylthiophene DsbA inhibitors slow S. Typhimurium growth in minimal media, phenocopying S. Typhimurium isogenic dsbA null mutants. Through passaging experiments, we found that DsbA inhibitor resistance was not induced under conditions that rapidly induced resistance to ciprofloxacin, an antibiotic commonly used to treat Salmonella infections. Furthermore, no mutations were identified in the dsbA gene of inhibitor‐treated S. Typhimurium, and S. Typhimurium virulence remained susceptible to DsbA inhibitors. Our work demonstrates that under in vitro pathophysiological conditions, DsbA inhibitors can have both antivirulence and antibiotic action. Importantly, our finding that DsbA inhibitors appear to be evolutionarily robust offers promise for their further development as next‐generation antimicrobials against Gram‐negative pathogens.
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Affiliation(s)
- Rabeb Dhouib
- Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Herston QLD Australia.,Centre for Immunology and Infection Control School of Biomedical Sciences Queensland University of Technology Herston QLD Australia
| | - Dimitrios Vagenas
- Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Herston QLD Australia
| | - Yaoqin Hong
- Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Herston QLD Australia.,Centre for Immunology and Infection Control School of Biomedical Sciences Queensland University of Technology Herston QLD Australia
| | - Anthony D Verderosa
- Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Herston QLD Australia.,Centre for Immunology and Infection Control School of Biomedical Sciences Queensland University of Technology Herston QLD Australia
| | - Jennifer L Martin
- Griffith Institute for Drug Discovery Griffith University Nathan QLD Australia.,University of Wollongong Wollongong NSW Australia
| | - Begoña Heras
- La Trobe Institute for Molecular Science La Trobe University Bundoora VIC Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation School of Biomedical Sciences Queensland University of Technology Herston QLD Australia.,Centre for Immunology and Infection Control School of Biomedical Sciences Queensland University of Technology Herston QLD Australia
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11
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Bolle ECL, Verderosa AD, Dhouib R, Parker TJ, Fraser JF, Dargaville TR, Totsika M. An in vitro Reconstructed Human Skin Equivalent Model to Study the Role of Skin Integration Around Percutaneous Devices Against Bacterial Infection. Front Microbiol 2020; 11:670. [PMID: 32477277 PMCID: PMC7240036 DOI: 10.3389/fmicb.2020.00670] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/24/2020] [Indexed: 01/19/2023] Open
Abstract
Percutaneous devices are a key technology in clinical practice, used to connect internal organs to external medical devices. Examples include prosthesis, catheters and electrical drivelines. Percutaneous devices breach the skin's natural barrier and create an entry point for pathogens, making device infections a widespread problem. Modification of the percutaneous implant surface to increase skin integration with the aim to reduce subsequent infection is attracting a great deal of attention. While novel surfaces have been tested in various in vitro models used to study skin integration around percutaneous devices, no skin model has been reported, for the study of bacterial infection around percutaneous devices. Here, we report the establishment of an in vitro human skin equivalent model for driveline infections caused by Staphylococcus aureus, the most common cause of driveline-related infections. Three types of mock drivelines manufactured using melt electrowriting (smooth or porous un-seeded and porous pre-seeded with human fibroblasts) were implanted in human skin constructs and challenged with S. aureus. Our results show a high and stable load of S. aureus in association with the skin surface and no signs of S. aureus-induced tissue damage. Furthermore, our results demonstrate that bacterial migration along the driveline surface occurs in micro-gaps caused by insufficient skin integration between the driveline and the surrounding skin consistent with clinical reports from explanted patient drivelines. Thus, the human skin-driveline infection model presented here provides a clinically-relevant and versatile experimental platform for testing novel device surfaces and infection therapeutics.
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Affiliation(s)
- Eleonore C. L. Bolle
- Tissue Repair and Translational Physiology Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
- The Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia
- Infection and Immunity Research Program, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Anthony D. Verderosa
- Infection and Immunity Research Program, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Rabeb Dhouib
- Infection and Immunity Research Program, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Tony J. Parker
- Tissue Repair and Translational Physiology Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - John F. Fraser
- The Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia
| | - Tim R. Dargaville
- Tissue Repair and Translational Physiology Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Makrina Totsika
- Infection and Immunity Research Program, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
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Verderosa AD, Dhouib R, Fairfull-Smith KE, Totsika M. Nitroxide Functionalized Antibiotics Are Promising Eradication Agents against Staphylococcus aureus Biofilms. Antimicrob Agents Chemother 2019; 64:e01685-19. [PMID: 31636066 PMCID: PMC7187575 DOI: 10.1128/aac.01685-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/09/2019] [Indexed: 01/10/2023] Open
Abstract
Treatment of biofilm-related Staphylococcus aureus infections represents an important medical challenge worldwide, as biofilms, even those involving drug-susceptible S. aureus strains, are highly refractory to conventional antibiotic therapy. Nitroxides were recently shown to induce the dispersal of Gram-negative biofilms in vitro, but their action against Gram-positive bacterial biofilms remains unknown. Here, we demonstrate that the biofilm dispersal activity of nitroxides extends to S. aureus, a clinically important Gram-positive pathogen. Coadministration of the nitroxide CTEMPO (4-carboxy-2,2,6,6-tetramethylpiperidin-1-yloxyl) with ciprofloxacin significantly improved the biofilm eradication activity of the antibiotic against S. aureus Moreover, covalently linking the nitroxide to the antibiotic moiety further reduced the ciprofloxacin minimal biofilm eradication concentration. Microscopy analysis revealed that fluorescent nitroxide-antibiotic hybrids could penetrate S. aureus biofilms and enter cells localized at the surface and base of the biofilm structure. No toxicity to human cells was observed for the nitroxide CTEMPO or the nitroxide-antibiotic hybrids. Taken together, our results show that nitroxides can mediate the dispersal of Gram-positive biofilms and that dual-acting biofilm eradication antibiotics may provide broad-spectrum therapies for the treatment of biofilm-related infections.
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Affiliation(s)
- Anthony D Verderosa
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Rabeb Dhouib
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Kathryn E Fairfull-Smith
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
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Abstract
Most free-living bacteria can attach to surfaces and aggregate to grow into multicellular communities encased in extracellular polymeric substances called biofilms. Biofilms are recalcitrant to antibiotic therapy and a major cause of persistent and recurrent infections by clinically important pathogens worldwide (e.g., Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus). Currently, most biofilm remediation strategies involve the development of biofilm-inhibition agents, aimed at preventing the early stages of biofilm formation, or biofilm-dispersal agents, aimed at disrupting the biofilm cell community. While both strategies offer some clinical promise, neither represents a direct treatment and eradication strategy for established biofilms. Consequently, the discovery and development of biofilm eradication agents as comprehensive, stand-alone biofilm treatment options has become a fundamental area of research. Here we review our current understanding of biofilm antibiotic tolerance mechanisms and provide an overview of biofilm remediation strategies, focusing primarily on the most promising biofilm eradication agents and approaches. Many of these offer exciting prospects for the future of biofilm therapeutics for a large number of infections that are currently refractory to conventional antibiotics.
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Affiliation(s)
- Anthony D Verderosa
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kathryn E Fairfull-Smith
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, Australia
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14
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Verderosa AD, Dhouib R, Fairfull-Smith KE, Totsika M. Profluorescent Fluoroquinolone-Nitroxides for Investigating Antibiotic⁻Bacterial Interactions. Antibiotics (Basel) 2019; 8:antibiotics8010019. [PMID: 30836686 PMCID: PMC6466543 DOI: 10.3390/antibiotics8010019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 02/27/2019] [Accepted: 02/27/2019] [Indexed: 01/13/2023] Open
Abstract
Fluorescent probes are widely used for imaging and measuring dynamic processes in living cells. Fluorescent antibiotics are valuable tools for examining antibiotic⁻bacterial interactions, antimicrobial resistance and elucidating antibiotic modes of action. Profluorescent nitroxides are 'switch on' fluorescent probes used to visualize and monitor intracellular free radical and redox processes in biological systems. Here, we have combined the inherent fluorescent and antimicrobial properties of the fluoroquinolone core structure with the fluorescence suppression capabilities of a nitroxide to produce the first example of a profluorescent fluoroquinolone-nitroxide probe. Fluoroquinolone-nitroxide (FN) 14 exhibited significant suppression of fluorescence (>36-fold), which could be restored via radical trapping (fluoroquinolone-methoxyamine 17) or reduction to the corresponding hydroxylamine 20. Importantly, FN 14 was able to enter both Gram-positive and Gram-negative bacterial cells, emitted a measurable fluorescence signal upon cell entry (switch on), and retained antibacterial activity. In conclusion, profluorescent nitroxide antibiotics offer a new powerful tool for visualizing antibiotic⁻bacterial interactions and researching intracellular chemical processes.
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Affiliation(s)
- Anthony D Verderosa
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia.
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4006, Australia.
| | - Rabeb Dhouib
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4006, Australia.
| | - Kathryn E Fairfull-Smith
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia.
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4006, Australia.
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15
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Verderosa AD, Harris J, Dhouib R, Totsika M, Fairfull-Smith KE. Eradicating uropathogenic Escherichia coli biofilms with a ciprofloxacin-dinitroxide conjugate. Medchemcomm 2019; 10:699-711. [PMID: 31191860 DOI: 10.1039/c9md00062c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 02/19/2019] [Indexed: 11/21/2022]
Abstract
Urinary tract infections (UTIs) are amongst the most common and prevalent infectious diseases worldwide, with uropathogenic Escherichia coli (UPEC) reported as the main causative pathogen. Fluoroquinolone antibiotics are commonly used to treat UTIs but for infections involving UPEC biofilms, which are commonly associated with catheter use and recurrent episodes, ciprofloxacin is often ineffective. Here we report the development of a ciprofloxacin-dinitroxide (CDN) conjugate with potent UPEC biofilm-eradication activity. CDN 11 exhibited a 2-fold increase in potency over the parent antibiotic ciprofloxacin against UPEC biofilms. Moreover, CDN 11 resulted in almost complete UPEC biofilm cell eradication (99.7%) at concentrations as low as 12.5 μM, and significantly potentiated ciprofloxacin's biofilm-eradication activity against UPEC upon co-administration. The biofilm-eradication activity of CDN 11 highlights the potential of nitroxide functionalized antibiotics as a promising strategy for the treatment of biofilm-related UTIs.
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Affiliation(s)
- Anthony D Verderosa
- Queensland University of Technology , School of Chemistry, Physics and Mechanical Engineering , 2 George St , Brisbane , Queensland 4001 , Australia . .,Queensland University of Technology , School of Biomedical Sciences , Institute of Health and Biomedical Innovation , 300 Herston Rd , Brisbane , Queensland 4006 , Australia .
| | - Jessica Harris
- Queensland University of Technology , School of Chemistry, Physics and Mechanical Engineering , 2 George St , Brisbane , Queensland 4001 , Australia .
| | - Rabeb Dhouib
- Queensland University of Technology , School of Biomedical Sciences , Institute of Health and Biomedical Innovation , 300 Herston Rd , Brisbane , Queensland 4006 , Australia .
| | - Makrina Totsika
- Queensland University of Technology , School of Biomedical Sciences , Institute of Health and Biomedical Innovation , 300 Herston Rd , Brisbane , Queensland 4006 , Australia .
| | - Kathryn E Fairfull-Smith
- Queensland University of Technology , School of Chemistry, Physics and Mechanical Engineering , 2 George St , Brisbane , Queensland 4001 , Australia .
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16
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Tan A, Li WS, Verderosa AD, Blakeway LV, D Mubaiwa T, Totsika M, Seib KL. Moraxella catarrhalis NucM is an entry nuclease involved in extracellular DNA and RNA degradation, cell competence and biofilm scaffolding. Sci Rep 2019; 9:2579. [PMID: 30796312 PMCID: PMC6384898 DOI: 10.1038/s41598-019-39374-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/18/2019] [Indexed: 11/10/2022] Open
Abstract
Moraxella catarrhalis is a host-adapted bacterial pathogen that causes otitis media and exacerbations of chronic obstructive pulmonary disease. This study characterises the conserved M. catarrhalis extracellular nuclease, a member of the ββα metal finger family of nucleases, that we have named NucM. NucM shares conserved sequence motifs from the ββα nuclease family, including the DRGH catalytic core and Mg2+ co-ordination site, but otherwise shares little primary sequence identity with other family members, such as the Serratia Nuc and pneumococcal EndA nucleases. NucM is secreted from the cell and digests linear and circular nucleic acid. However, it appears that a proportion of NucM is also associated with the cell membrane and acts as an entry nuclease, facilitating transformation of M. catarrhalis cells. This is the first example of a ββα nuclease in a Gram negative bacteria that acts as an entry nuclease. In addition to its role in competence, NucM affects cell aggregation and biofilm formation by M. catarrhalis, with ΔnucM mutants having increased biofilm biomass. NucM is likely to increase the ability of cells to survive and persist in vivo, increasing the virulence of M. catarrhalis and potentially affecting the behaviour of other pathogens that co-colonise the otorhinolaryngological niche.
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Affiliation(s)
- Aimee Tan
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Wing-Sze Li
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Anthony D Verderosa
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, 4006, Australia
| | - Luke V Blakeway
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Tsitsi D Mubaiwa
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, 4006, Australia
| | - Kate L Seib
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4215, Australia.
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17
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Verderosa AD, de la Fuente-Núñez C, Mansour SC, Cao J, Lu TK, Hancock REW, Fairfull-Smith KE. Ciprofloxacin-nitroxide hybrids with potential for biofilm control. Eur J Med Chem 2017; 138:590-601. [PMID: 28709125 DOI: 10.1016/j.ejmech.2017.06.058] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 01/15/2023]
Abstract
As bacterial biofilms display extreme tolerance to conventional antibiotic treatments, it has become imperative to develop new antibacterial strategies with alternative mechanisms of action. Herein, we report the synthesis of a series of ciprofloxacin-nitroxide conjugates and their corresponding methoxyamine derivatives in high yield. This was achieved by linking various nitroxides or methoxyamines to the secondary amine of the piperazine ring of ciprofloxacin using amide bond coupling. Biological evaluation of the prepared compounds on preformed P. aeruginosa biofilms in flow cells revealed substantial dispersal with ciprofloxacin-nitroxide hybrid 25, and virtually complete killing and removal (94%) of established biofilms in the presence of ciprofloxacin-nitroxide hybrid 27. Compounds 25-28 were shown to be non-toxic in both human embryonic kidney 293 (HEK 293) cells and human muscle rhabdomyosarcoma (RD) cells at concentrations up to 40 μM. Significantly, these hybrids demonstrate the potential of antimicrobial-nitroxide agents to overcome the resistance of biofilms to antimicrobials via stimulation of biofilm dispersal or through direct cell killing.
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Affiliation(s)
- Anthony D Verderosa
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Faculty of Science and Engineering, Queensland University of Technology, Queensland 4001, Australia
| | - César de la Fuente-Núñez
- Synthetic Biology Group, MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, United States; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; Broad Institute of MIT and Harvard, Cambridge, MA, United States; Harvard Biophysics Program, Harvard University, Boston, MA, United States; The Center for Microbiome Informatics and Therapeutics, Cambridge, MA, United States
| | - Sarah C Mansour
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jicong Cao
- Synthetic Biology Group, MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, United States; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; Broad Institute of MIT and Harvard, Cambridge, MA, United States; Harvard Biophysics Program, Harvard University, Boston, MA, United States; The Center for Microbiome Informatics and Therapeutics, Cambridge, MA, United States
| | - Timothy K Lu
- Synthetic Biology Group, MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, United States; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; Broad Institute of MIT and Harvard, Cambridge, MA, United States; Harvard Biophysics Program, Harvard University, Boston, MA, United States; The Center for Microbiome Informatics and Therapeutics, Cambridge, MA, United States
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kathryn E Fairfull-Smith
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Faculty of Science and Engineering, Queensland University of Technology, Queensland 4001, Australia.
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