51
|
Teicoplanin-A New Use for an Old Drug in the COVID-19 Era? Pharmaceuticals (Basel) 2021; 14:ph14121227. [PMID: 34959628 PMCID: PMC8708781 DOI: 10.3390/ph14121227] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 12/22/2022] Open
Abstract
Teicoplanin is an antibiotic that has been actively used in medical practice since 1986 to treat serious Gram-positive bacterial infections. Due to its efficiency and low cytotoxicity, teicoplanin has also been used for patients with complications, including pediatric and immunocompromised patients. Although teicoplanin is accepted as an antibacterial drug, its action against RNA viruses, including SARS-CoV2, has been proven in vitro. Here, we provide a thorough overview of teicoplanin usage in medicine, based on the current literature. We summarize infection sites treated with teicoplanin, concentrations of the antibiotic in different organs, and side effects. Finally, we summarize all available data about the antiviral activity of teicoplanin. We believe that, due to the extensive experience of teicoplanin usage in clinical settings to treat bacterial infections and its demonstrated activity against SARS-CoV2, teicoplanin could become a drug of choice in the treatment of COVID-19 patients. Teicoplanin stops the replication of the virus and at the same time avoids the development of Gram-positive bacterial co-infections.
Collapse
|
52
|
Vimberg V, Buriánková K, Mazumdar A, Branny P, Novotná GB. Role of membrane proteins in bacterial resistance to antimicrobial peptides. Med Res Rev 2021; 42:1023-1036. [PMID: 34796517 DOI: 10.1002/med.21869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 09/19/2021] [Accepted: 10/21/2021] [Indexed: 11/07/2022]
Abstract
Several natural antimicrobial peptides (AMPs), including the novel semisynthetic lipoglycopeptide antibiotics telavancin, dalbavancin, and oritavancin, have been approved for clinical use to address the growing problem of multiple antibiotic-resistant Gram-positive bacterial infections. Nevertheless, the efficacy of these antibiotics has already been compromised. The SARS-CoV-2 pandemic led to the increased clinical use of all antibiotics, further promoting the development of bacterial resistance. Therefore, it is critical to gain a deeper understanding of the role of resistance mechanisms to minimize the consequential risks of long-term antibiotic use and misuse. Here, we summarize for the first time the current knowledge of resistance mechanisms that have been shown to cause resistance to clinically used AMPs, with particular focus on membrane proteins that have been reported to interfere with the activity of AMPs by affecting the binding of AMPs to bacteria.
Collapse
Affiliation(s)
- Vladimir Vimberg
- Laboratory for Biology of Secondary Metabolism, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Karolína Buriánková
- Laboratory of Cell Signaling, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Aninda Mazumdar
- Laboratory for Biology of Secondary Metabolism, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Pavel Branny
- Laboratory of Cell Signaling, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Gabriela B Novotná
- Laboratory for Biology of Secondary Metabolism, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| |
Collapse
|
53
|
Two Novel Semisynthetic Lipoglycopeptides Active against Staphylococcus aureus Biofilms and Cells in Late Stationary Growth Phase. Pharmaceuticals (Basel) 2021; 14:ph14111182. [PMID: 34832964 PMCID: PMC8619453 DOI: 10.3390/ph14111182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/06/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
The increase in antibiotic resistance among Gram-positive bacteria underscores the urgent need to develop new antibiotics. New antibiotics should target actively growing susceptible bacteria that are resistant to clinically accepted antibiotics including bacteria that are not growing or are protected in a biofilm environment. In this paper, we compare the in vitro activities of two new semisynthetic glycopeptide antibiotics, MA79 and ERJ390, with two clinically used glycopeptide antibiotics-vancomycin and teicoplanin. The new antibiotics effectively killed not only exponentially growing cells of Staphylococcus aureus, but also cells in the stationary growth phase and biofilm.
Collapse
|
54
|
Lactococcus lactis Resistance to Aureocin A53- and Enterocin L50-Like Bacteriocins and Membrane-Targeting Peptide Antibiotics Relies on the YsaCB-KinG-LlrG Four-Component System. Antimicrob Agents Chemother 2021; 65:e0092121. [PMID: 34516250 DOI: 10.1128/aac.00921-21] [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] [Indexed: 01/20/2023] Open
Abstract
Resistance to nonribosomally synthesized peptide antibiotics affecting the cell envelope is well studied and mostly associated with the action of peptide-sensing and detoxification (PSD) modules, which consist of a two-component system (TCS) and an ATP-binding cassette (ABC) transporter. In contrast, the mechanisms of resistance to ribosomally synthesized bacterial toxic peptides (bacteriocins), which also affect the cell envelope, are studied to a lesser extent, and the possible cross-resistance between them and antibiotics is still poorly understood. In the present study, we investigated the development of resistance of Lactococcus lactis to aureocin A53- and enterocin L50-like bacteriocins and cross-resistance with antibiotics. First, 19 spontaneous mutants resistant to their representatives were selected and also displayed changes in sensitivity to peptide antibiotics acting on the cell envelope (bacitracin, daptomycin, and gramicidin). Sequencing of their genomes revealed mutations in genes encoding the ABC transporter YsaCB and the TCS KinG-LlrG, the emergence of which induced the upregulation of the dltABCD and ysaDCB operons. The ysaB mutations were either nonsense or frameshift mutations and led to the generation of truncated YsaB but with the conserved N-terminal FtsX domain intact. Deletions of ysaCB or llrG had a minor effect on the resistance of the obtained mutants to the tested bacteriocins, daptomycin, and gramicidin, indicating that the development of resistance is dependent on the modification of the protein rather than its absence. In further corroboration of the above-mentioned conclusion, we show that the FtsX domain, which functions effectively when YsaB is lacking its central and C-terminal parts, is critical for resistance to these antimicrobials.
Collapse
|
55
|
Alternatives to Fight Vancomycin-Resistant Staphylococci and Enterococci. Antibiotics (Basel) 2021; 10:antibiotics10091116. [PMID: 34572698 PMCID: PMC8471638 DOI: 10.3390/antibiotics10091116] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/25/2022] Open
Abstract
Gram positive pathogens are a significant cause of healthcare-associated infections, with Staphylococci and Enterococci being the most prevalent ones. Vancomycin, a last resort glycopeptide, is used to fight these bacteria but the emergence of resistance against this drug leaves some patients with few therapeutic options. To counter this issue, new generations of antibiotics have been developed but resistance has already been reported. In this article, we review the strategies in place or in development to counter vancomycin-resistant pathogens. First, an overview of traditional antimicrobials already on the market or in the preclinical or clinical pipeline used individually or in combination is summarized. The second part focuses on the non-traditional antimicrobials, such as antimicrobial peptides, bacteriophages and nanoparticles. The conclusion is that there is hitherto no substitute equivalent to vancomycin. However, promising strategies based on drugs with multiple mechanisms of action and treatments based on bacteriophages possibly combined with conventional antibiotics are hoped to provide treatment options for vancomycin-resistant Gram-positive pathogens.
Collapse
|
56
|
Pantel A, Nachar O, Boudet A, Loubet P, Schuldiner S, Cellier N, Sotto A, Dunyach-Remy C, Lavigne JP. In vitro activity of dalbavancin against Gram-positive bacteria isolated from diabetic foot osteomyelitis. J Antimicrob Chemother 2021; 76:2057-2060. [PMID: 33842980 DOI: 10.1093/jac/dkab117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/15/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Diabetic foot infections (DFIs) represent a serious threat to public health because of their frequency and the severity of their consequences, i.e. osteomyelitis and amputation. The management of diabetic foot osteomyelitis (DFOM) requires prolonged antibiotic therapy. In Western countries, Gram-positive bacteria are the most commonly encountered pathogens. OBJECTIVES This study evaluated the in vitro activity of dalbavancin, a novel lipoglycopeptide with extended half-life, recently marketed in Europe for acute bacterial skin and skin structure infections, on a panel of Gram-positive bacteria responsible for DFOM. METHODS Dalbavancin activity was evaluated against a panel of Gram-positive bacterial strains isolated from bone biopsies performed by a trained surgeon among patients with suspected DFOM. MICs were determined using MIC Test Strips (Liofilchem) and confirmed with the EUCAST broth microdilution method. Three other antimicrobial agents (vancomycin, teicoplanin and ceftobiprole) were used as comparators. RESULTS Dalbavancin showed excellent activity against all Gram-positive bacterial strains tested, including one teicoplanin-resistant Staphylococcus epidermidis isolate. With MIC50 and MIC90 values of 0.047 and 0.094 mg/L, respectively, dalbavancin showed the most potent in vitro activity among antimicrobial agents tested. CONCLUSIONS With its efficacy, good tolerability and unique pharmacokinetic properties, dalbavancin appears to be a promising treatment for DFOM involving Gram-positive bacteria.
Collapse
Affiliation(s)
- Alix Pantel
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, Clinique du Pied Diabétique Gard Occitanie, CHU Nîmes, Nîmes, France
| | - Oriane Nachar
- Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Agathe Boudet
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, Clinique du Pied Diabétique Gard Occitanie, CHU Nîmes, Nîmes, France
| | - Paul Loubet
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, Service des Maladies Infectieuses et Tropicales, Clinique du Pied Diabétique Gard Occitanie, CHU Carémeau, Nîmes, France
| | - Sophie Schuldiner
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, Service des Maladies Métaboliques et Endocriniennes, Clinique du Pied Diabétique Gard Occitanie, CHU Carémeau, Nîmes, France
| | - Nicolas Cellier
- Service de Chirurgie Orthopédique, Clinique du Pied Diabétique Gard Occitanie, CHU Carémeau, Nîmes, France
| | - Albert Sotto
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, Service des Maladies Infectieuses et Tropicales, Clinique du Pied Diabétique Gard Occitanie, CHU Carémeau, Nîmes, France
| | - Catherine Dunyach-Remy
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, Clinique du Pied Diabétique Gard Occitanie, CHU Nîmes, Nîmes, France
| | - Jean-Philippe Lavigne
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, Clinique du Pied Diabétique Gard Occitanie, CHU Nîmes, Nîmes, France
| |
Collapse
|
57
|
Ready-to-Eat Sandwiches as Source of Pathogens Endowed with Antibiotic Resistance and Other Virulence Factors. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11167177] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The aim of this study was to evaluate and characterize the bacterial load present in twenty-four Ready-To-Eat (RTE) sandwiches, purchased at refrigerated vending machines and supermarkets in the province of Modena (Italy). We isolated 54 bacterial strains, including pathogens of interest in food safety, such as Listeria, Staphylococcus, Enterococcus, Yersinia, Aeromonas and Acinetobacter spp. Phenotypic tests have been performed on these pathogens to detect the presence of virulence factors, such as gelatinase production and hemolytic capability. To test their antibiotic resistance features, the minimum inhibitory concentration (MIC) against eight commonly used antibiotics (Amikacin, Ciprofloxacin, Ampicillin, Oxacillin, Imipenem, Tetracycline, Erythromycin and Vancomycin) was also evaluated. The results showed that among the 54 isolates, fifty percent (50%) belonged to harmless microorganisms (Leuconostoc and Lactococcus), whereas the remaining fifty percent (50%) included pathogenic bacteria (Listeria ivanovii, Listeria monocytogenes, Staphylococcus aureus, Yersinia, and Citrobacter spp.), species responsible for pathologies often difficult to treat due to the presence of antibiotic resistance features. This study demonstrates the importance of thorough controls, both during the production and marketing of RTE food like sandwiches, to avoid reaching the infectious load and the onset of pathologies, particularly dangerous for old and immunocompromised patients.
Collapse
|
58
|
Sarkar P, Basak D, Mukherjee R, Bandow JE, Haldar J. Alkyl-Aryl-Vancomycins: Multimodal Glycopeptides with Weak Dependence on the Bacterial Metabolic State. J Med Chem 2021; 64:10185-10202. [PMID: 34233118 DOI: 10.1021/acs.jmedchem.1c00449] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Resistance to last-resort antibiotics such as vancomycin for Gram-positive bacterial infections necessitates the development of new therapeutics. Furthermore, the ability of bacteria to survive antibiotic therapy through formation of biofilms and persister cells complicates treatment. Toward this, we report alkyl-aryl-vancomycins (AAVs), with high potency against vancomycin-resistant enterococci and staphylococci. Unlike vancomycin, the lead compound AAV-qC10 was bactericidal and weakly dependent on bacterial metabolism. This resulted in complete eradication of non-growing cells of MRSA and disruption of its biofilms. In addition to inhibiting cell wall biosynthesis like vancomycin, AAV-qC10 also depolarizes and permeabilizes the membrane. More importantly, the compound delocalized the cell division protein MinD, thereby impairing bacterial growth through multiple pathways. The potential of AAV-qC10 is exemplified by its superior efficacy against MRSA in a murine thigh infection model as compared to vancomycin. This work paves the way for structural optimization and drug development for combating drug-resistant bacterial infections.
Collapse
Affiliation(s)
- Paramita Sarkar
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India
| | - Debajyoti Basak
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India
| | - Riya Mukherjee
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India
| | - Julia E Bandow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Universitätsstraße 150, Bochum 44780, Germany
| | - Jayanta Haldar
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India
| |
Collapse
|
59
|
Gan BH, Gaynord J, Rowe SM, Deingruber T, Spring DR. The multifaceted nature of antimicrobial peptides: current synthetic chemistry approaches and future directions. Chem Soc Rev 2021; 50:7820-7880. [PMID: 34042120 PMCID: PMC8689412 DOI: 10.1039/d0cs00729c] [Citation(s) in RCA: 162] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Indexed: 12/13/2022]
Abstract
Bacterial infections caused by 'superbugs' are increasing globally, and conventional antibiotics are becoming less effective against these bacteria, such that we risk entering a post-antibiotic era. In recent years, antimicrobial peptides (AMPs) have gained significant attention for their clinical potential as a new class of antibiotics to combat antimicrobial resistance. In this review, we discuss several facets of AMPs including their diversity, physicochemical properties, mechanisms of action, and effects of environmental factors on these features. This review outlines various chemical synthetic strategies that have been applied to develop novel AMPs, including chemical modifications of existing peptides, semi-synthesis, and computer-aided design. We will also highlight novel AMP structures, including hybrids, antimicrobial dendrimers and polypeptides, peptidomimetics, and AMP-drug conjugates and consider recent developments in their chemical synthesis.
Collapse
Affiliation(s)
- Bee Ha Gan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Josephine Gaynord
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Sam M Rowe
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Tomas Deingruber
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - David R Spring
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| |
Collapse
|
60
|
Khodaparast L, Wu G, Khodaparast L, Schmidt BZ, Rousseau F, Schymkowitz J. Bacterial Protein Homeostasis Disruption as a Therapeutic Intervention. Front Mol Biosci 2021; 8:681855. [PMID: 34150852 PMCID: PMC8206779 DOI: 10.3389/fmolb.2021.681855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/04/2021] [Indexed: 12/15/2022] Open
Abstract
Cells have evolved a complex molecular network, collectively called the protein homeostasis (proteostasis) network, to produce and maintain proteins in the appropriate conformation, concentration and subcellular localization. Loss of proteostasis leads to a reduction in cell viability, which occurs to some degree during healthy ageing, but is also the root cause of a group of diverse human pathologies. The accumulation of proteins in aberrant conformations and their aggregation into specific beta-rich assemblies are particularly detrimental to cell viability and challenging to the protein homeostasis network. This is especially true for bacteria; it can be argued that the need to adapt to their changing environments and their high protein turnover rates render bacteria particularly vulnerable to the disruption of protein homeostasis in general, as well as protein misfolding and aggregation. Targeting bacterial proteostasis could therefore be an attractive strategy for the development of novel antibacterial therapeutics. This review highlights advances with an antibacterial strategy that is based on deliberately inducing aggregation of target proteins in bacterial cells aiming to induce a lethal collapse of protein homeostasis. The approach exploits the intrinsic aggregation propensity of regions residing in the hydrophobic core regions of the polypeptide sequence of proteins, which are genetically conserved because of their essential role in protein folding and stability. Moreover, the molecules were designed to target multiple proteins, to slow down the build-up of resistance. Although more research is required, results thus far allow the hope that this strategy may one day contribute to the arsenal to combat multidrug-resistant bacterial infections.
Collapse
Affiliation(s)
- Laleh Khodaparast
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Guiqin Wu
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Ladan Khodaparast
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Béla Z Schmidt
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Frederic Rousseau
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, Leuven, Belgium
| |
Collapse
|
61
|
Mat Rani NNI, Mustafa Hussein Z, Mustapa F, Azhari H, Sekar M, Chen XY, Mohd Amin MCI. Exploring the possible targeting strategies of liposomes against methicillin-resistant Staphylococcus aureus (MRSA). Eur J Pharm Biopharm 2021; 165:84-105. [PMID: 33974973 DOI: 10.1016/j.ejpb.2021.04.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 03/26/2021] [Accepted: 04/26/2021] [Indexed: 12/12/2022]
Abstract
Multi antibiotic-resistant bacterial infections are on the rise due to the overuse of antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the pathogens listed under the category of serious threats where vancomycin remains the mainstay treatment despite the availability of various antibacterial agents. Recently, decreased susceptibility to vancomycin from clinical isolates of MRSA has been reported and has drawn worldwide attention as it is often difficult to overcome and leads to increased medical costs, mortality, and longer hospital stays. Development of antibiotic delivery systems is often necessary to improve bioavailability and biodistribution, in order to reduce antibiotic resistance and increase the lifespan of antibiotics. Liposome entrapment has been used as a method to allow higher drug dosing apart from reducing toxicity associated with drugs. The surface of the liposomes can also be designed and enhanced with drug-release properties, active targeting, and stealth effects to prevent recognition by the mononuclear phagocyte system, thus enhancing its circulation time. The present review aimed to highlight the possible targeting strategies of liposomes against MRSA bacteremia systemically while investigating the magnitude of this effect on the minimum inhibitory concentration level.
Collapse
Affiliation(s)
- Nur Najihah Izzati Mat Rani
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia; Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, 30450 Ipoh, Perak, Malaysia
| | - Zahraa Mustafa Hussein
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Fahimi Mustapa
- Hospital Batu Gajah Jalan Changkat, 31000 Batu Gajah, Perak, Malaysia
| | - Hanisah Azhari
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Mahendran Sekar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, 30450 Ipoh, Perak, Malaysia
| | - Xiang Yi Chen
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Mohd Cairul Iqbal Mohd Amin
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.
| |
Collapse
|
62
|
Moiseenko EI, Erdei R, Grammatikova NE, Mirchink EP, Isakova EB, Pereverzeva ER, Batta G, Shchekotikhin AE. Aminoalkylamides of Eremomycin Exhibit an Improved Antibacterial Activity. Pharmaceuticals (Basel) 2021; 14:379. [PMID: 33921612 PMCID: PMC8072890 DOI: 10.3390/ph14040379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 11/16/2022] Open
Abstract
After decades, the glycopeptide vancomycin is still the preferred antibiotic against resistant strains of Gram-positive bacteria. Although its clinical use is strictly regulated, the gradual spread of vancomycin-resistant bacteria, such as glycopeptide-resistant and glycopeptide-intermediate Staphylococcus aureus and vancomycin-resistant Enterococcus spp., is a serious health problem. Based on the literature data and previous studies, our main goal was to assess the antimicrobial potential and to study the structure-activity relationship of new eremomycin aminoalkylamides. We designed and synthesized a series of new eremomycin amides in which eremomycin is conjugated with a hydrophobic arylalkyl group via an alkylenediamine spacer, and tested their antibacterial activities on a panel of Gram-positive strains that were sensitive and resistant to a "gold-standard" vancomycin. Based on the data obtained, the structure-activity relationships were investigated, and a lead compound was selected for in-depth testing. Research carried out using an in vivo model of staphylococcus sepsis, acute toxicity studies, and the estimated therapeutic index also showed the advantage of the selected eremomycin amide derivative in particular, as well as the chosen direction in general.
Collapse
Affiliation(s)
- Elena I. Moiseenko
- Gause Institute of New Antibiotics, 119021 Moscow, Russia; (E.I.M.); (N.E.G.); (E.P.M.); (E.B.I.); (E.R.P.)
| | - Réka Erdei
- Department of Organic Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (R.E.); (G.B.)
| | - Natalia E. Grammatikova
- Gause Institute of New Antibiotics, 119021 Moscow, Russia; (E.I.M.); (N.E.G.); (E.P.M.); (E.B.I.); (E.R.P.)
| | - Elena P. Mirchink
- Gause Institute of New Antibiotics, 119021 Moscow, Russia; (E.I.M.); (N.E.G.); (E.P.M.); (E.B.I.); (E.R.P.)
| | - Elena B. Isakova
- Gause Institute of New Antibiotics, 119021 Moscow, Russia; (E.I.M.); (N.E.G.); (E.P.M.); (E.B.I.); (E.R.P.)
| | - Eleonora R. Pereverzeva
- Gause Institute of New Antibiotics, 119021 Moscow, Russia; (E.I.M.); (N.E.G.); (E.P.M.); (E.B.I.); (E.R.P.)
| | - Gyula Batta
- Department of Organic Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (R.E.); (G.B.)
| | - Andrey E. Shchekotikhin
- Gause Institute of New Antibiotics, 119021 Moscow, Russia; (E.I.M.); (N.E.G.); (E.P.M.); (E.B.I.); (E.R.P.)
| |
Collapse
|
63
|
Lade H, Kim JS. Bacterial Targets of Antibiotics in Methicillin-Resistant Staphylococcus aureus. Antibiotics (Basel) 2021; 10:398. [PMID: 33917043 PMCID: PMC8067735 DOI: 10.3390/antibiotics10040398] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/17/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent bacterial pathogens and continues to be a leading cause of morbidity and mortality worldwide. MRSA is a commensal bacterium in humans and is transmitted in both community and healthcare settings. Successful treatment remains a challenge, and a search for new targets of antibiotics is required to ensure that MRSA infections can be effectively treated in the future. Most antibiotics in clinical use selectively target one or more biochemical processes essential for S. aureus viability, e.g., cell wall synthesis, protein synthesis (translation), DNA replication, RNA synthesis (transcription), or metabolic processes, such as folic acid synthesis. In this review, we briefly describe the mechanism of action of antibiotics from different classes and discuss insights into the well-established primary targets in S. aureus. Further, several components of bacterial cellular processes, such as teichoic acid, aminoacyl-tRNA synthetases, the lipid II cycle, auxiliary factors of β-lactam resistance, two-component systems, and the accessory gene regulator quorum sensing system, are discussed as promising targets for novel antibiotics. A greater molecular understanding of the bacterial targets of antibiotics has the potential to reveal novel therapeutic strategies or identify agents against antibiotic-resistant pathogens.
Collapse
Affiliation(s)
| | - Jae-Seok Kim
- Department of Laboratory Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul 05355, Korea;
| |
Collapse
|
64
|
Suzuki M, Sujino T, Chiba S, Harada Y, Goto M, Takahashi R, Mita M, Hamase K, Kanai T, Ito M, Waldor MK, Yasui M, Sasabe J. Host-microbe cross-talk governs amino acid chirality to regulate survival and differentiation of B cells. SCIENCE ADVANCES 2021; 7:7/10/eabd6480. [PMID: 33658193 PMCID: PMC7929512 DOI: 10.1126/sciadv.abd6480] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Organisms use l-amino acids (l-aa) for most physiological processes. Unlike other organisms, bacteria chiral-convert l-aa to d-configurations as essential components of their cell walls and as signaling molecules in their ecosystems. Mammals recognize microbe-associated molecules to initiate immune responses, but roles of bacterial d-amino acids (d-aa) in mammalian immune systems remain largely unknown. Here, we report that amino acid chirality balanced by bacteria-mammal cross-talk modulates intestinal B cell fate and immunoglobulin A (IgA) production. Bacterial d-aa stimulate M1 macrophages and promote survival of intestinal naïve B cells. Mammalian intestinal d-aa catabolism limits the number of B cells and restricts growth of symbiotic bacteria that activate T cell-dependent IgA class switching of the B cells. Loss of d-aa catabolism results in excessive IgA production and dysbiosis with altered IgA coating on bacteria. Thus, chiral conversion of amino acids is linked to bacterial recognition by mammals to control symbiosis with bacteria.
Collapse
Affiliation(s)
- Masataka Suzuki
- Department of Pharmacology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
- Research Fellow of the Japan Society for the Promotion of Science (JSPS), Chiyoda-Ku, Tokyo 102-0083, Japan
| | - Tomohisa Sujino
- Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Sayako Chiba
- Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Yoichi Harada
- Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Motohito Goto
- Central Institute for Experimental Animals, Kawasaki, Kanagawa 210-0821, Japan
| | - Riichi Takahashi
- Central Institute for Experimental Animals, Kawasaki, Kanagawa 210-0821, Japan
| | | | - Kenji Hamase
- Department of Drug Discovery and Evolution, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Takanori Kanai
- Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Mamoru Ito
- Central Institute for Experimental Animals, Kawasaki, Kanagawa 210-0821, Japan
| | - Matthew Kaden Waldor
- Howard Hughes Medical Institute and Harvard Medical School, Boston, MA 02115, USA
| | - Masato Yasui
- Department of Pharmacology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Jumpei Sasabe
- Department of Pharmacology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
| |
Collapse
|
65
|
Interplay between ESKAPE Pathogens and Immunity in Skin Infections: An Overview of the Major Determinants of Virulence and Antibiotic Resistance. Pathogens 2021; 10:pathogens10020148. [PMID: 33540588 PMCID: PMC7912840 DOI: 10.3390/pathogens10020148] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/16/2022] Open
Abstract
The skin is the largest organ in the human body, acting as a physical and immunological barrier against pathogenic microorganisms. The cutaneous lesions constitute a gateway for microbial contamination that can lead to chronic wounds and other invasive infections. Chronic wounds are considered as serious public health problems due the related social, psychological and economic consequences. The group of bacteria known as ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter sp.) are among the most prevalent bacteria in cutaneous infections. These pathogens have a high level of incidence in hospital environments and several strains present phenotypes of multidrug resistance. In this review, we discuss some important aspects of skin immunology and the involvement of ESKAPE in wound infections. First, we introduce some fundamental aspects of skin physiology and immunology related to cutaneous infections. Following this, the major virulence factors involved in colonization and tissue damage are highlighted, as well as the most frequently detected antimicrobial resistance genes. ESKAPE pathogens express several virulence determinants that overcome the skin's physical and immunological barriers, enabling them to cause severe wound infections. The high ability these bacteria to acquire resistance is alarming, particularly in the hospital settings where immunocompromised individuals are exposed to these pathogens. Knowledge about the virulence and resistance markers of these species is important in order to develop new strategies to detect and treat their associated infections.
Collapse
|
66
|
Izsépi L, Erdei R, Tevyashova AN, Grammatikova NE, Shchekotikhin AE, Herczegh P, Batta G. Bacterial Cell Wall Analogue Peptides Control the Oligomeric States and Activity of the Glycopeptide Antibiotic Eremomycin: Solution NMR and Antimicrobial Studies. Pharmaceuticals (Basel) 2021; 14:ph14020083. [PMID: 33499349 PMCID: PMC7911593 DOI: 10.3390/ph14020083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/05/2021] [Accepted: 01/18/2021] [Indexed: 12/18/2022] Open
Abstract
For some time, glycopeptide antibiotics have been considered the last line of defense against Methicillin-resistant Staphylococcus aureus (MRSA). However, vancomycin resistance of Gram-positive bacteria is an increasingly emerging worldwide health problem. The mode of action of glycopeptide antibiotics is essentially the binding of peptidoglycan cell-wall fragments terminating in the d-Ala-d-Ala sequence to the carboxylate anion binding pocket of the antibiotic. Dimerization of these antibiotics in aqueous solution was shown to persist and even to enhance the antibacterial effect in a co-operative manner. Some works based on solid state (ss) Nuclear Magnetic Resonance (NMR) studies questioned the presence of dimers under the conditions of ssNMR while in a few cases, higher-order oligomers associated with contiguous back-to-back and face-to-face dimers were observed in the crystal phase. However, it is not proved if such oligomers persist in aqueous solutions. With the aid of 15N-labelled eremomycin using 15N relaxation and diffusion NMR methods, we observed tetramers and octamers when the N-Ac-d-Ala-d-Ala dipeptide was added. To the contrary, the N-Ac-d-Ala or (N-Ac)2-l-Lys-d-Ala-d-Ala tripeptide did not induce higher-order oligomers. These observations are interesting examples of tailored supramolecular self-organization. New antimicrobial tests have also been carried out with these self-assemblies against MRSA and VRE (resistant) strains.
Collapse
Affiliation(s)
- László Izsépi
- Doctoral School of Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1., Hungary;
- Department of Organic Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1., Hungary;
| | - Réka Erdei
- Department of Organic Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1., Hungary;
| | - Anna N. Tevyashova
- Gause Institute of New Antibiotics, 11 B. Pirogovskaya, 119021 Moscow, Russia; (A.N.T.); (N.E.G.); (A.E.S.)
| | - Natalia E. Grammatikova
- Gause Institute of New Antibiotics, 11 B. Pirogovskaya, 119021 Moscow, Russia; (A.N.T.); (N.E.G.); (A.E.S.)
| | - Andrey E. Shchekotikhin
- Gause Institute of New Antibiotics, 11 B. Pirogovskaya, 119021 Moscow, Russia; (A.N.T.); (N.E.G.); (A.E.S.)
| | - Pál Herczegh
- Department of Pharmaceutical Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1., Hungary;
| | - Gyula Batta
- Department of Organic Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1., Hungary;
- Correspondence:
| |
Collapse
|
67
|
The Lactococcal dgkB ( yecE) and dxsA Genes for Lipid Metabolism Are Involved in the Resistance to Cell Envelope-Acting Antimicrobials. Int J Mol Sci 2021; 22:ijms22031014. [PMID: 33498351 PMCID: PMC7864038 DOI: 10.3390/ijms22031014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/18/2021] [Accepted: 01/18/2021] [Indexed: 01/01/2023] Open
Abstract
The emergence of antibiotic-resistant bacteria led to an urgent need for next-generation antimicrobial agents with novel mechanisms of action. The use of positively charged antimicrobial peptides that target cytoplasmic membrane is an especially promising strategy since essential functions and the conserved structure of the membrane hinder the development of bacterial resistance. Aureocin A53- and enterocin L50-like bacteriocins are highly cationic, membrane-targeting antimicrobial peptides that have potential as next-generation antibiotics. However, the mechanisms of resistance to these bacteriocins and cross-resistance against antibiotics must be examined before application to ensure their safe use. Here, in the model bacterium Lactococcus lactis, we studied the development of resistance to selected aureocin A53- and enterocin L50-like bacteriocins and its correlation with antibiotics. First, to generate spontaneous resistant mutants, L.lactis was exposed to bacteriocin BHT-B. Sequencing of their genomes revealed single nucleotide polymorphisms (SNPs) in the dgkB (yecE) and dxsA genes encoding diacylglycerol kinase and 1-deoxy-D-xylulose 5-phosphate synthase, respectively. Then, selected mutants underwent susceptibility tests with a wide array of bacteriocins and antibiotics. The highest alterations in the sensitivity of studied mutants were seen in the presence of cytoplasmic membrane targeting bacteriocins (K411, Ent7, EntL50, WelM, SalC, nisin) and antibiotics (daptomycin and gramicidin) as well as lipid II cycle-blocking bacteriocins (nisin and Lcn972) and antibiotics (bacitracin). Interestingly, decreased via the SNPs accumulation sensitivity to membrane-active bacteriocins and antibiotics resulted in the concurrently increased vulnerability to bacitracin, carbenicillin, or chlortetracycline. It is suspected that SNPs may result in alterations to the efficiency of the nascent enzymes rather than a total loss of their function as neither deletion nor overexpression of dxsA restored the phenotype observed in spontaneous mutants.
Collapse
|
68
|
Olivera C, Le VVH, Davenport C, Rakonjac J. In vitro synergy of 5-nitrofurans, vancomycin and sodium deoxycholate against Gram-negative pathogens. J Med Microbiol 2021; 70. [PMID: 33448923 PMCID: PMC8346734 DOI: 10.1099/jmm.0.001304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Introduction There is an urgent need for effective therapies against bacterial infections, especially those caused by antibiotic-resistant Gram-negative pathogens. Hypothesis Synergistic combinations of existing antimicrobials show promise due to their enhanced efficacies and reduced dosages which can mitigate adverse effects, and therefore can be used as potential antibacterial therapy. Aim In this study, we sought to characterize the in vitro interaction of 5-nitrofurans, vancomycin and sodium deoxycholate (NVD) against pathogenic bacteria. Methodology The synergy of the NVD combination was investigated in terms of growth inhibition and bacterial killing using checkerboard and time-kill assays, respectively. Results Using a three-dimensional checkerboard assay, we showed that 5-nitrofurans, sodium deoxycholate and vancomycin interact synergistically in the growth inhibition of 15 out of 20 Gram-negative strains tested, including clinically significant pathogens such as carbapenemase-producing Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii, and interact indifferently against the Gram-positive strains tested. The time-kill assay further confirmed that the triple combination was bactericidal in a synergistic manner. Conclusion This study demonstrates the synergistic effect of 5-nitrofurans, sodium deoxycholate and vancomycin against Gram-negative pathogens and highlights the potential of the combination as a treatment for Gram-negative and Gram-positive infections.
Collapse
Affiliation(s)
- Catrina Olivera
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Vuong Van Hung Le
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Catherine Davenport
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Jasna Rakonjac
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| |
Collapse
|
69
|
Pajares-Chamorro N, Wagley Y, Maduka CV, Youngstrom DW, Yeger A, Badylak SF, Hammer ND, Hankenson K, Chatzistavrou X. Silver-doped bioactive glass particles for in vivo bone tissue regeneration and enhanced methicillin-resistant Staphylococcus aureus (MRSA) inhibition. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 120:111693. [PMID: 33545854 PMCID: PMC8168684 DOI: 10.1016/j.msec.2020.111693] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 10/27/2020] [Accepted: 10/30/2020] [Indexed: 11/18/2022]
Abstract
Infection is a significant risk factor for failed healing of bone and other tissues. We have developed a sol-gel (solution-gelation) derived bioactive glass doped with silver ions (Ag-BG), tailored to provide non-cytotoxic antibacterial activity while significantly enhancing osteoblast-lineage cell growth in vitro and bone regeneration in vivo. Our objective was to engineer a biomaterial that combats bacterial infection while maintaining the capability to promote bone growth. We observed that Ag-BG inhibits bacterial growth and potentiates the efficacy of conventional antibiotic treatment. Ag-BG microparticles enhance cell proliferation and osteogenic differentiation in human bone marrow stromal cells (hBMSC) in vitro. Moreover, in vivo tests using a calvarial defect model in mice demonstrated that Ag-BG microparticles induce bone regeneration. This novel system with dual biological and advanced antibacterial properties is a promising therapeutic for combating resistant bacteria while triggering new bone formation.
Collapse
Affiliation(s)
- Natalia Pajares-Chamorro
- Department of Chemical Engineering and Materials Science, College of Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Yadav Wagley
- Department of Orthopaedic Surgery, University of Michigan Medical School, Ann Arbor, MI 48103, USA
| | - Chima V Maduka
- Department of Orthopaedic Surgery, University of Michigan Medical School, Ann Arbor, MI 48103, USA; Institute for Quantitative Health Sciences and Technology, Michigan State University, East Lansing, MI 48824, USA; Comparative Medicine and Integrative Biology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Daniel W Youngstrom
- Department of Orthopaedic Surgery, University of Michigan Medical School, Ann Arbor, MI 48103, USA
| | - Alyssa Yeger
- Department of Orthopaedic Surgery, University of Michigan Medical School, Ann Arbor, MI 48103, USA
| | - Stephen F Badylak
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Neal D Hammer
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Kurt Hankenson
- Department of Orthopaedic Surgery, University of Michigan Medical School, Ann Arbor, MI 48103, USA
| | - Xanthippi Chatzistavrou
- Department of Chemical Engineering and Materials Science, College of Engineering, Michigan State University, East Lansing, MI 48824, USA.
| |
Collapse
|
70
|
Donkor ES, Kotey FCN. Methicillin-Resistant Staphylococcus aureus in the Oral Cavity: Implications for Antibiotic Prophylaxis and Surveillance. Infect Dis (Lond) 2020; 13:1178633720976581. [PMID: 33402829 PMCID: PMC7739134 DOI: 10.1177/1178633720976581] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 11/03/2020] [Indexed: 02/06/2023] Open
Abstract
The oral cavity harbors a multitude of commensal flora, which may constitute a repository of antibiotic resistance determinants. In the oral cavity, bacteria form biofilms, and this facilitates the acquisition of antibiotic resistance genes through horizontal gene transfer. Recent reports indicate high methicillin-resistant Staphylococcus aureus (MRSA) carriage rates in the oral cavity. Establishment of MRSA in the mouth could be enhanced by the wide usage of antibiotic prophylaxis among at-risk dental procedure candidates. These changes in MRSA epidemiology have important implications for MRSA preventive strategies, clinical practice, as well as the methodological approaches to carriage studies of the organism.
Collapse
Affiliation(s)
- Eric S Donkor
- Department of Medical Microbiology, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Fleischer CN Kotey
- Department of Medical Microbiology, College of Health Sciences, University of Ghana, Accra, Ghana
- FleRhoLife Research Consult, Teshie, Accra, Ghana
| |
Collapse
|
71
|
Browne K, Chakraborty S, Chen R, Willcox MDP, Black DS, Walsh WR, Kumar N. A New Era of Antibiotics: The Clinical Potential of Antimicrobial Peptides. Int J Mol Sci 2020; 21:ijms21197047. [PMID: 32987946 PMCID: PMC7582481 DOI: 10.3390/ijms21197047] [Citation(s) in RCA: 202] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/22/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
Antimicrobial resistance is a multifaceted crisis, imposing a serious threat to global health. The traditional antibiotic pipeline has been exhausted, prompting research into alternate antimicrobial strategies. Inspired by nature, antimicrobial peptides are rapidly gaining attention for their clinical potential as they present distinct advantages over traditional antibiotics. Antimicrobial peptides are found in all forms of life and demonstrate a pivotal role in the innate immune system. Many antimicrobial peptides are evolutionarily conserved, with limited propensity for resistance. Additionally, chemical modifications to the peptide backbone can be used to improve biological activity and stability and reduce toxicity. This review details the therapeutic potential of peptide-based antimicrobials, as well as the challenges needed to overcome in order for clinical translation. We explore the proposed mechanisms of activity, design of synthetic biomimics, and how this novel class of antimicrobial compound may address the need for effective antibiotics. Finally, we discuss commercially available peptide-based antimicrobials and antimicrobial peptides in clinical trials.
Collapse
Affiliation(s)
- Katrina Browne
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney 2052, Australia; (K.B.); (S.C.); (R.C.)
| | - Sudip Chakraborty
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney 2052, Australia; (K.B.); (S.C.); (R.C.)
| | - Renxun Chen
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney 2052, Australia; (K.B.); (S.C.); (R.C.)
| | - Mark DP Willcox
- School of Optometry and Vision Science, University of New South Wales (UNSW) Sydney, Sydney 2052, Australia;
| | - David StClair Black
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney 2052, Australia; (K.B.); (S.C.); (R.C.)
- Correspondence: (D.S.B.); (N.K.); Tel.: +612-9385-4657 (D.S.B.); +612-9385-4698 (N.K.)
| | - William R Walsh
- Surgical and Orthopaedic Research Laboratories (SORL), Prince of Wales Clinical School, Prince of Wales Hospital, University of New South Wales (UNSW), Randwick 2031, Australia;
| | - Naresh Kumar
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney 2052, Australia; (K.B.); (S.C.); (R.C.)
- Correspondence: (D.S.B.); (N.K.); Tel.: +612-9385-4657 (D.S.B.); +612-9385-4698 (N.K.)
| |
Collapse
|
72
|
Liu Y, Rebollo-Ramirez S, Larrouy-Maumus G. Metabolomics reveals that the cAMP receptor protein regulates nitrogen and peptidoglycan synthesis in Mycobacterium tuberculosis. RSC Adv 2020; 10:26212-26219. [PMID: 33747441 PMCID: PMC7938724 DOI: 10.1039/d0ra05153e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/07/2020] [Indexed: 12/30/2022] Open
Abstract
Mycobacterium tuberculosis requires extensive sensing and response to environment for its successful survival and pathogenesis, and signalling by cyclic adenosine 3',5'-monophosphate (cAMP) is an important mechanism. cAMP regulates expression of target genes via interaction with downstream proteins, one of which is cAMP receptor protein (CRP), a global transcriptional regulator. Previous genomic works had identified regulon of CRP and investigated transcriptional changes in crp deletion mutant, however a link to downstream metabolomic events were lacking, which would help better understand roles of CRP. This work aims at investigating changes at metabolome level in M. tuberculosis crp deletion mutant combining untargeted LC-MS analysis and 13C isotope tracing analysis. The results were compared with previously published RNA sequencing data. We identified increasing abundances of metabolites related to nitrogen metabolism including ornithine, citrulline and glutamate derivatives, while 13C isotope labelling analysis further showed changes in turnover of these metabolites and amino acids, suggesting regulatory roles of CRP in nitrogen metabolism. Upregulation of diaminopimelic acid and its related genes also suggested role of CRP in regulation of peptidoglycan synthesis. This study provides insights on metabolomic aspects of cAMP-CRP regulatory pathway in M. tuberculosis and links to previously published transcriptomic data drawing a more complete map.
Collapse
Affiliation(s)
- Yi Liu
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, UK.
| | - Sonia Rebollo-Ramirez
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, UK.
| | - Gerald Larrouy-Maumus
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, UK.
| |
Collapse
|
73
|
Slizovskiy IB, Mukherjee K, Dean CJ, Boucher C, Noyes NR. Mobilization of Antibiotic Resistance: Are Current Approaches for Colocalizing Resistomes and Mobilomes Useful? Front Microbiol 2020; 11:1376. [PMID: 32695079 PMCID: PMC7338343 DOI: 10.3389/fmicb.2020.01376] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/28/2020] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial resistance (AMR) poses a global human and animal health threat, and predicting AMR persistence and transmission remains an intractable challenge. Shotgun metagenomic sequencing can help overcome this by enabling characterization of AMR genes within all bacterial taxa, most of which are uncultivatable in laboratory settings. Shotgun sequencing, therefore, provides a more comprehensive glance at AMR "potential" within samples, i.e., the "resistome." However, the risk inherent within a given resistome is predicated on the genomic context of various AMR genes, including their presence within mobile genetic elements (MGEs). Therefore, resistome risk stratification can be advanced if AMR profiles are considered in light of the flanking mobilizable genomic milieu (e.g., plasmids, integrative conjugative elements (ICEs), phages, and other MGEs). Because such mediators of horizontal gene transfer (HGT) are involved in uptake by pathogens, investigators are increasingly interested in characterizing that resistome fraction in genomic proximity to HGT mediators, i.e., the "mobilome"; we term this "colocalization." We explored the utility of common colocalization approaches using alignment- and assembly-based techniques, on clinical (human) and agricultural (cattle) fecal metagenomes, obtained from antimicrobial use trials. Ordination revealed that tulathromycin-treated cattle experienced a shift in ICE and plasmid composition versus untreated animals, though the resistome was unaffected during the monitoring period. Contrarily, the human resistome and mobilome composition both shifted shortly after antimicrobial administration, though this rebounded to pre-treatment status. Bayesian networks revealed statistical AMR-MGE co-occurrence in 19 and 2% of edges from the cattle and human networks, respectively, suggesting a putatively greater mobility potential of AMR in cattle feces. Conversely, using Mobility Index (MI) and overlap analysis, abundance of de novo-assembled contigs supporting resistomes flanked by MGE increased shortly post-exposure within human metagenomes, though > 40 days after peak dose such contigs were rare (∼2%). MI was not substantially altered by antimicrobial exposure across all cattle metagenomes, ranging 0.5-4.0%. We highlight that current alignment- and assembly-based methods estimating resistome mobility yield contradictory and incomplete results, likely constrained by approach-specific data inputs, and bioinformatic limitations. We discuss recent laboratory and computational advancements that may enhance resistome risk analysis in clinical, regulatory, and commercial applications.
Collapse
Affiliation(s)
- Ilya B Slizovskiy
- Food-Centric Corridor, Infectious Disease Laboratory, Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Kingshuk Mukherjee
- Department of Computer and Information Science and Engineering, The Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, United States
| | - Christopher J Dean
- Food-Centric Corridor, Infectious Disease Laboratory, Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Christina Boucher
- Department of Computer and Information Science and Engineering, The Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, United States
| | - Noelle R Noyes
- Food-Centric Corridor, Infectious Disease Laboratory, Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| |
Collapse
|
74
|
Yushchuk O, Binda E, Marinelli F. Glycopeptide Antibiotic Resistance Genes: Distribution and Function in the Producer Actinomycetes. Front Microbiol 2020; 11:1173. [PMID: 32655512 PMCID: PMC7325946 DOI: 10.3389/fmicb.2020.01173] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/07/2020] [Indexed: 12/22/2022] Open
Abstract
Glycopeptide antibiotics (GPAs) are considered drugs of "last resort" for the treatment of life-threatening infections caused by relevant Gram-positive pathogens (enterococci, staphylococci, and clostridia). Driven by the issue of the never-stopping evolution of bacterial antibiotic resistance, research on GPA biosynthesis and resistance is developing fast in modern "post-genomic" era. It is today widely accepted that resistance mechanisms emerging in pathogens have been acquired from the soil-dwelling antibiotic-producing actinomycetes, which use them to avoid suicide during production, rather than being orchestrated de novo by pathogen bacteria upon continued treatment. Actually, more and more genomes of GPA producers are being unraveled, carrying a broad collection of differently arranged GPA resistance (named van) genes. In the producer actinomycetes, van genes are generally associated with the antibiotic biosynthetic gene clusters (BGCs) deputed to GPA biosynthesis, being probably transferred/arranged together, favoring a possible co-regulation between antibiotic production and self-resistance. GPA BGC-associated van genes have been also found mining public databases of bacterial genomic and metagenomic sequences. Interestingly, some BGCs for antibiotics, seemingly unrelated to GPAs (e.g., feglymycin), carry van gene homologues. Herein, we would like to cover the recent advances on the distribution of GPA resistance genes in genomic and metagenomics datasets related to GPA potential/proved producer microorganisms. A thorough understanding of GPA resistance in the producing microorganisms may prove useful in the future surveillance of emerging mechanisms of resistance to this clinically relevant antibiotic class.
Collapse
Affiliation(s)
- Oleksandr Yushchuk
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Elisa Binda
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| |
Collapse
|
75
|
Wu S, Lin K, Liu Y, Zhang H, Lei L. Two-component signaling pathways modulate drug resistance of Staphylococcus aureus (Review). Biomed Rep 2020; 13:5. [PMID: 32607234 PMCID: PMC7323452 DOI: 10.3892/br.2020.1312] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 05/07/2020] [Indexed: 02/05/2023] Open
Abstract
As the issues surrounding antibiotic-resistant strains of Staphylococcus aureus (S. aureus) are becoming increasingly serious concerns, it is imperative to investigate new therapeutic targets to successfully treat patients with S. aureus infections. The two-component signal transduction system is one of the primary pathways by which bacteria adapt to the external environment, and it serves an important role in regulating virulence gene expression, cell wall synthesis, biofilm formation and bacterial activity. There are 17 two-component signaling pathways in S. aureus, among which WalKR/VicSR/YycGF, AirSR/YhcSR, vancomycin resistance associated regulator/sensor and LytRS have been demonstrated to serve vital roles in regulating bacterial resistance, and are hypothesized to be potential targets for the treatment of S. aureus infections. The present review assesses the mechanism of the two-component signaling pathways associated with the development of S. aureus resistance.
Collapse
Affiliation(s)
- Shizhou Wu
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Kaifeng Lin
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yunjie Liu
- West China School of Public Health, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Hui Zhang
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Lei Lei
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| |
Collapse
|
76
|
Van Dort BA, Baysari MT, Carland JE, Stocker SL, Braithwaite HE, Fernon AR, Day RO. Education to improve vancomycin use: the perspectives of educators and education recipients. Intern Med J 2020; 50:565-572. [DOI: 10.1111/imj.14408] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/20/2019] [Accepted: 06/11/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Bethany A. Van Dort
- The University of Sydney, Charles Perkins CentreFaculty of Health Sciences Sydney New South Wales Australia
- Australian Institute of Health InnovationMacquarie University Sydney New South Wales Australia
- Department of Clinical Pharmacology and ToxicologySt Vincent’s Hospital Sydney New South Wales Australia
- Faculty of MedicineUNSW Sydney Sydney New South Wales Australia
| | - Melissa T. Baysari
- The University of Sydney, Charles Perkins CentreFaculty of Health Sciences Sydney New South Wales Australia
- Australian Institute of Health InnovationMacquarie University Sydney New South Wales Australia
| | - Jane E. Carland
- Department of Clinical Pharmacology and ToxicologySt Vincent’s Hospital Sydney New South Wales Australia
- St Vincent’s Clinical SchoolUNSW Sydney Sydney New South Wales Australia
| | - Sophie L. Stocker
- Department of Clinical Pharmacology and ToxicologySt Vincent’s Hospital Sydney New South Wales Australia
- St Vincent’s Clinical SchoolUNSW Sydney Sydney New South Wales Australia
| | - Hannah E. Braithwaite
- St Vincent’s Clinical SchoolUNSW Sydney Sydney New South Wales Australia
- St Vincent’s Hospital Sydney Sydney New South Wales Australia
| | - Anna R. Fernon
- St Vincent’s Hospital Sydney Sydney New South Wales Australia
| | - Richard O. Day
- Department of Clinical Pharmacology and ToxicologySt Vincent’s Hospital Sydney New South Wales Australia
- Faculty of MedicineUNSW Sydney Sydney New South Wales Australia
- St Vincent’s Clinical SchoolUNSW Sydney Sydney New South Wales Australia
| |
Collapse
|
77
|
Jian Y, Lv H, Liu J, Huang Q, Liu Y, Liu Q, Li M. Dynamic Changes of Staphylococcus aureus Susceptibility to Vancomycin, Teicoplanin, and Linezolid in a Central Teaching Hospital in Shanghai, China, 2008-2018. Front Microbiol 2020; 11:908. [PMID: 32528428 PMCID: PMC7247803 DOI: 10.3389/fmicb.2020.00908] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/17/2020] [Indexed: 11/16/2022] Open
Abstract
Vancomycin, teicoplanin, and linezolid are the major treatment options for methicillin-resistant Staphylococcus aureus (MRSA). The phenomenon of progressive increase in the value of vancomycin minimum inhibitory concentration (MIC) for S. aureus (i.e., vancomycin MIC “creep”), has been reported; however, it is still a controversial concept because the results of research remain inconclusive. In this study, we conducted a retrospective epidemiologic investigation for more than 10 years to elucidate the dynamic changes of the MICs of vancomycin, teicoplanin, and linezolid in S. aureus in a central teaching hospital in Shanghai, China. A total of 2911 S. aureus isolates was recovered from 2008 to 2018, to which the MICs of three antimicrobials were tested by the E-test method and subsequently correlated with the characteristics of oxacillin susceptibility, clonotypes, and antimicrobial consumption during the study period. The proportion of MRSA dramatically decreased from 2008 to 2018 (from 84 to 49%, p < 0.001). Vancomycin MIC decline was identified both in MRSA and methicillin-sensitive S. aureus (MSSA) (both with p < 0.001), and both the dominating MRSA clone ST5 and pre-dominating MRSA clone ST239 displayed vancomycin MIC decline (p < 0.001, p = 0.040), while teicoplanin MIC decline was only identified in MRSA (p = 0.037). Linezolid MIC creep was identified in total S. aureus (p < 0.001), but linezolid in MRSA as well as teicoplanin and linezolid in MSSA displayed no statistically distinct trends of MIC creep or decline. Clinical consumption of linezolid increased significantly from 2012 to 2018 (p = 0.003), which correlated with vancomycin MIC decline in S. aureus (p = 0.005). The results of this study clearly demonstrate the dynamic changes of the MICs of these three primary antimicrobials in S. aureus, and suggest that changes in clinical antibiotic use may affect bacterial resistance.
Collapse
Affiliation(s)
- Ying Jian
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Huiying Lv
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Junlan Liu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qian Huang
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yao Liu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qian Liu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Min Li
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
78
|
Vimberg V, Zieglerová L, Buriánková K, Branny P, Balíková Novotná G. VanZ Reduces the Binding of Lipoglycopeptide Antibiotics to Staphylococcus aureus and Streptococcus pneumoniae Cells. Front Microbiol 2020; 11:566. [PMID: 32318043 PMCID: PMC7146870 DOI: 10.3389/fmicb.2020.00566] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/16/2020] [Indexed: 11/30/2022] Open
Abstract
vanZ, a member of the VanA glycopeptide resistance gene cluster, confers resistance to lipoglycopeptide antibiotics independent of cell wall precursor modification by the vanHAX genes. Orthologs of vanZ are present in the genomes of many clinically relevant bacteria, including Enterococcus faecium and Streptococcus pneumoniae; however, vanZ genes are absent in Staphylococcus aureus. Here, we show that the expression of enterococcal vanZ paralogs in S. aureus increases the minimal inhibitory concentrations of lipoglycopeptide antibiotics teicoplanin, dalbavancin, oritavancin and new teicoplanin pseudoaglycone derivatives. The reduction in the binding of fluorescently labeled teicoplanin to the cells suggests the mechanism of VanZ-mediated resistance. In addition, using a genomic vanZ gene knockout mutant of S. pneumoniae, we have shown that the ability of VanZ proteins to compromise the activity of lipoglycopeptide antibiotics by reducing their binding is a more general feature of VanZ-superfamily proteins.
Collapse
Affiliation(s)
- Vladimir Vimberg
- Laboratory for Biology of Secondary Metabolism, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Leona Zieglerová
- Laboratory for Biology of Secondary Metabolism, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Karolína Buriánková
- Laboratory of Cell Signaling, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Pavel Branny
- Laboratory of Cell Signaling, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Gabriela Balíková Novotná
- Laboratory for Biology of Secondary Metabolism, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| |
Collapse
|
79
|
Guo Y, Song G, Sun M, Wang J, Wang Y. Prevalence and Therapies of Antibiotic-Resistance in Staphylococcus aureus. Front Cell Infect Microbiol 2020; 10:107. [PMID: 32257966 PMCID: PMC7089872 DOI: 10.3389/fcimb.2020.00107] [Citation(s) in RCA: 302] [Impact Index Per Article: 75.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/27/2020] [Indexed: 12/17/2022] Open
Abstract
Infectious diseases are the second most important cause of human death worldwide; Staphylococcus aureus (S. aureus) is a very common human pathogenic microorganism that can trigger a variety of infectious diseases, such as skin and soft tissue infections, endocarditis, osteomyelitis, bacteremia, and lethal pneumonia. Moreover, according to the sensitivity to antibiotic drugs, S. aureus can be divided into methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). In recent decades, due to the evolution of bacteria and the abuse of antibiotics, the drug resistance of S. aureus has gradually increased, the infection rate of MRSA has increased worldwide, and the clinical anti-infective treatment for MRSA has become more difficult. Accumulating evidence has demonstrated that the resistance mechanisms of S. aureus are very complex, especially for MRSA, which is resistant to many kinds of antibiotics. Therefore, understanding the drug resistance of MRSA in a timely manner and elucidating its drug resistance mechanism at the molecular level are of great significance for the treatment of S. aureus infection. A large number of researchers believe that analyzing the molecular characteristics of S. aureus can help provide a basis for designing effective prevention and treatment measures against hospital infections caused by S. aureus and further monitor the evolution of S. aureus. This paper reviews the research status of MSSA and MRSA, the detailed mechanisms of the intrinsic antibiotic resistance and the acquired antibiotic resistance, the advanced research on anti-MRSA antibiotics and novel therapeutic strategies for MRSA treatment.
Collapse
Affiliation(s)
- Yunlei Guo
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Guanghui Song
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Meiling Sun
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Juan Wang
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yi Wang
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| |
Collapse
|
80
|
Stogios PJ, Savchenko A. Molecular mechanisms of vancomycin resistance. Protein Sci 2020; 29:654-669. [PMID: 31899563 DOI: 10.1002/pro.3819] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 12/18/2022]
Abstract
Vancomycin and related glycopeptides are drugs of last resort for the treatment of severe infections caused by Gram-positive bacteria such as Enterococcus species, Staphylococcus aureus, and Clostridium difficile. Vancomycin was long considered immune to resistance due to its bactericidal activity based on binding to the bacterial cell envelope rather than to a protein target as is the case for most antibiotics. However, two types of complex resistance mechanisms, each comprised of a multi-enzyme pathway, emerged and are now widely disseminated in pathogenic species, thus threatening the clinical efficiency of vancomycin. Vancomycin forms an intricate network of hydrogen bonds with the d-Ala-d-Ala region of Lipid II, interfering with the peptidoglycan layer maturation process. Resistance to vancomycin involves degradation of this natural precursor and its replacement with d-Ala-d-lac or d-Ala-d-Ser alternatives to which vancomycin has low affinity. Through extensive research over 30 years after the initial discovery of vancomycin resistance, remarkable progress has been made in molecular understanding of the enzymatic cascades responsible. Progress has been driven by structural studies of the key components of the resistance mechanisms which provided important molecular understanding such as, for example, the ability of this cascade to discriminate between vancomycin sensitive and resistant peptidoglycan precursors. Important structural insights have been also made into the molecular evolution of vancomycin resistance enzymes. Altogether this molecular data can accelerate inhibitor discovery and optimization efforts to reverse vancomycin resistance. Here, we overview our current understanding of this complex resistance mechanism with a focus on the structural and molecular aspects.
Collapse
Affiliation(s)
- Peter J Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada.,Center for Structural Genomics of Infectious Diseases (CSGID)
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada.,Center for Structural Genomics of Infectious Diseases (CSGID).,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
81
|
Guo Y, Song G, Sun M, Wang J, Wang Y. Prevalence and Therapies of Antibiotic-Resistance in Staphylococcus aureus. Front Cell Infect Microbiol 2020; 10:107. [PMID: 32257966 DOI: 10.3389/fcimb.2020.00107/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/27/2020] [Indexed: 05/20/2023] Open
Abstract
Infectious diseases are the second most important cause of human death worldwide; Staphylococcus aureus (S. aureus) is a very common human pathogenic microorganism that can trigger a variety of infectious diseases, such as skin and soft tissue infections, endocarditis, osteomyelitis, bacteremia, and lethal pneumonia. Moreover, according to the sensitivity to antibiotic drugs, S. aureus can be divided into methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). In recent decades, due to the evolution of bacteria and the abuse of antibiotics, the drug resistance of S. aureus has gradually increased, the infection rate of MRSA has increased worldwide, and the clinical anti-infective treatment for MRSA has become more difficult. Accumulating evidence has demonstrated that the resistance mechanisms of S. aureus are very complex, especially for MRSA, which is resistant to many kinds of antibiotics. Therefore, understanding the drug resistance of MRSA in a timely manner and elucidating its drug resistance mechanism at the molecular level are of great significance for the treatment of S. aureus infection. A large number of researchers believe that analyzing the molecular characteristics of S. aureus can help provide a basis for designing effective prevention and treatment measures against hospital infections caused by S. aureus and further monitor the evolution of S. aureus. This paper reviews the research status of MSSA and MRSA, the detailed mechanisms of the intrinsic antibiotic resistance and the acquired antibiotic resistance, the advanced research on anti-MRSA antibiotics and novel therapeutic strategies for MRSA treatment.
Collapse
Affiliation(s)
- Yunlei Guo
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Guanghui Song
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Meiling Sun
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Juan Wang
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yi Wang
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| |
Collapse
|
82
|
Antimicrobial resistance in methicillin-resistant Staphylococcus aureus to newer antimicrobial agents. Antimicrob Agents Chemother 2019:AAC.01216-19. [PMID: 31527033 DOI: 10.1128/aac.01216-19] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) result in significant morbidity and mortality for patients in both community and health care settings. This is primarily due to the difficulty in treating MRSA, which is often resistant to multiple classes of antibiotics. Understanding the mechanisms of antimicrobial resistance (AMR) in MRSA provides insight into the optimal use of antimicrobial agents in clinical practice and also underpins critical aspects of antimicrobial stewardship programs. In this review we delineate the mechanisms, prevalence, and clinical importance of resistance to antibiotics licensed in the past 20 years that target MRSA, as well as new drugs in the pipeline which are likely to be licensed soon. Current gaps in scientific knowledge about MRSA resistance mechanisms are discussed, and topics in the epidemiology of AMR in S. aureus that require further investigation are highlighted.
Collapse
|
83
|
Pajares-Chamorro N, Shook J, Hammer ND, Chatzistavrou X. Resurrection of antibiotics that methicillin-resistant Staphylococcus aureus resists by silver-doped bioactive glass-ceramic microparticles. Acta Biomater 2019; 96:537-546. [PMID: 31302297 DOI: 10.1016/j.actbio.2019.07.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/24/2019] [Accepted: 07/09/2019] [Indexed: 11/16/2022]
Abstract
This work describes a novel strategy to combat methicillin-resistant Staphylococcus aureus (MRSA) via the reactivation of inert antibiotics. This strategy exploits a multifunctional system consisting of bioactive glass-ceramic microparticles with antibacterial properties combined with various antibiotics to kill MRSA. Specifically, sol-gel derived silver-doped bioactive glass-ceramic microparticles (Ag-BG) combined with antibiotics that MRSA resists such as oxacillin or fosfomycin, significantly decreased the viability of MRSA. Ag-BG also potentiated the activity of vancomycin on static bacteria, which are typically resistant to this antibiotic. Notably, the synergistic activity is restricted to cell-envelope acting antibiotics as Ag-BG supplementation did not increase the efficacy of gentamicin. Bacteria viability assays and electron microscopy images demonstrate that Ag-BG synergizes to restore antibacterial activity to antibiotics that MRSA resists. The low cytotoxicity previously studied against oral bacteria, together with the known regenerative properties presented in previous studies, and the unique antibacterial properties observed in this work when they are combined with antibiotics, make this multifunctional system a promising approach for healing infected tissue. STATEMENT OF SIGNIFICANCE: This study addresses a very significant issue in the field of antibiotic resistance presenting an innovative way to clear MRSA, by utilizing bioactive glass-ceramic microparticles in combination with antibiotics. Multifunctional glass-ceramic microparticles doped with silver ions (Ag-BG) have been previously observed to exhibit bioactive and antibacterial properties. In this study Ag-BG microparticles were observed to synergize with antibiotics restoring their sensitivity against MRSA. This research work presents a novel approach to resurrect ineffective antibiotics and render them effective against MRSA. Cytotoxicity to eukaryotic cells is not anticipated, as it has been previously observed that these microparticles can trigger hard and soft dental tissue regeneration, when they are utilized in certain concentrations. This study opens a new avenue in the treatment of multidrug resistance bacteria.
Collapse
Affiliation(s)
- Natalia Pajares-Chamorro
- Department of Chemical Engineering and Material Science, College of Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - John Shook
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Neal D Hammer
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Xanthippi Chatzistavrou
- Department of Chemical Engineering and Material Science, College of Engineering, Michigan State University, East Lansing, MI 48824, USA.
| |
Collapse
|
84
|
Vimberg V, Gazak R, Szűcs Z, Borbás A, Herczegh P, Cavanagh JP, Zieglerova L, Závora J, Adámková V, Balikova Novotna G. Fluorescence assay to predict activity of the glycopeptide antibiotics. J Antibiot (Tokyo) 2018; 72:114-117. [DOI: 10.1038/s41429-018-0120-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/13/2018] [Accepted: 10/04/2018] [Indexed: 11/09/2022]
|
85
|
Multiple Low Frequency Ultrasound Enhances Bactericidal Activity of Vancomycin against Methicillin-Resistant Staphylococcus aureus Biofilms. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6023101. [PMID: 30364019 PMCID: PMC6186328 DOI: 10.1155/2018/6023101] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/16/2018] [Indexed: 11/17/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) biofilm infections are difficult to treat due to the high antimicrobial resistance of biofilm. Therefore, new treatments are needed for more effective bacteria clearance. This study was to investigate whether low frequency ultrasound (LFU) can enhance the activity of antimicrobial agents against MRSA biofilm infection. Broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of vancomycin (VAN), linezolid (LIN), and levofloxacin (LEV) against three clinical isolated strains, including one methicillin-susceptible Staphylococcus aureus (MSSA) strain and two MRSA strains. Effects of various influencing factors, such as antimicrobial agents, drug concentrations, ultrasonic intensity, and single (S-LFU, 5 or 15 min) or multiple ultrasound (M-LFU, 5 min every 8 h), on the inhibition of biofilms were investigated. The bactericidal effects of S-LFU or M-LFU on MRSA or MSSA biofilms were determined by colony counts. Right after ultrasound, synergistic effects were observed in groups of S-LFU combined with three antimicrobial agents against MSSA biofilm, but for MRSA biofilm, only S-LFU plus VAN had synergistic effect. At the time point of 24 h, M-LFU plus VAN treatment had synergistic bactericidal effect against MRSA and MSSA biofilms, and the synergy showed that VAN is concentration-dependent, but no synergistic effects were observed in all S-LFU combination groups. In conclusion, combination of M-LFU and antimicrobial agents had a better synergistic effect than S-LFU against MRSA or MSSA biofilm. LFU may be useful in treating biofilm infection in the future.
Collapse
|
86
|
Foster TJ. Can β-Lactam Antibiotics Be Resurrected to Combat MRSA? Trends Microbiol 2018; 27:26-38. [PMID: 30031590 DOI: 10.1016/j.tim.2018.06.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/25/2018] [Accepted: 06/22/2018] [Indexed: 01/26/2023]
Abstract
The use of β-lactam antibiotics to treat infections caused by Staphylococcus aureus has been severely compromised by the acquisition by horizontal gene transfer of a gene that encodes the β-lactam-insensitive penicillin-binding protein PBP2a. This allows methicillin-resistant S. aureus (MRSA) to proliferate in the presence of β-lactam antibiotics. Paradoxically the dependence on PBP2a for the essential transpeptidase activity in cell wall peptidoglycan biosynthesis is the 'Achilles heel' of MRSA. Compounds that disrupt the divisome, wall teichoic acid, and functional membrane microdomains act synergistically with β-lactams against MRSA. These include drugs such as statins that are widely used in human medicine. The antibiotics vancomycin and daptomycin are also synergistic with β-lactams, and combinations have been employed to treat persistent MRSA infections. An additional benefit of exposing MRSA to β-lactams could be a reduction in virulence mediated by interfering with the global regulator Agr. The mechanistic basis of synergy is discussed, and the possibility that β-lactams can be resurrected to combat MRSA infections is explored.
Collapse
Affiliation(s)
- Timothy J Foster
- Microbiology Department, Trinity College Dublin, Dublin 2, Ireland.
| |
Collapse
|
87
|
Foster TJ. Antibiotic resistance in Staphylococcus aureus. Current status and future prospects. FEMS Microbiol Rev 2018; 41:430-449. [PMID: 28419231 DOI: 10.1093/femsre/fux007] [Citation(s) in RCA: 391] [Impact Index Per Article: 65.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/12/2017] [Indexed: 12/11/2022] Open
Abstract
The major targets for antibiotics in staphylococci are (i) the cell envelope, (ii) the ribosome and (iii) nucleic acids. Several novel targets emerged from recent targeted drug discovery programmes including the ClpP protease and FtsZ from the cell division machinery. Resistance can either develop by horizontal transfer of resistance determinants encoded by mobile genetic elements viz plasmids, transposons and the staphylococcal cassette chromosome or by mutations in chromosomal genes. Horizontally acquired resistance can occur by one of the following mechanisms: (i) enzymatic drug modification and inactivation, (ii) enzymatic modification of the drug binding site, (iii) drug efflux, (iv) bypass mechanisms involving acquisition of a novel drug-resistant target, (v) displacement of the drug to protect the target. Acquisition of resistance by mutation can result from (i) alteration of the drug target that prevents the inhibitor from binding, (ii) derepression of chromosomally encoded multidrug resistance efflux pumps and (iii) multiple stepwise mutations that alter the structure and composition of the cell wall and/or membrane to reduce drug access to its target. This review focuses on development of resistance to currently used antibiotics and examines future prospects for new antibiotics and informed use of drug combinations.
Collapse
|
88
|
Abstract
Several new antimicrobial agents-daptomycin, ceftaroline, telavancin, dalbavancin, and-tedizolid have been approved for the treatment of staphylococcal infections, including methicillin-resistant Staphylococcus aureus (MRSA), in adults. Ceftaroline and daptomycin have been approved by the US Food and Drug Administration for use in children. Ceftaroline, a beta-lactam antibiotic with activity against MRSA, has been approved for treatment of community-acquired bacterial pneumonia and complicated skin and skin structure infections. Daptomycin has been approved for treatment of complicated skin and skin structure infections. In this article, we review the pharmacokinetics and pharmacodynamics of these antibiotics and available data on use in children.
Collapse
|
89
|
Streptococcus suis serotype 9 strain GZ0565 contains a type VII secretion system putative substrate EsxA that contributes to bacterial virulence and a vanZ-like gene that confers resistance to teicoplanin and dalbavancin in Streptococcus agalactiae. Vet Microbiol 2017. [PMID: 28622857 DOI: 10.1016/j.vetmic.2017.04.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Streptococcus suis (SS), an important pathogen for pigs, is not only considered as a zoonotic agent for humans, but is also recognized as a major reservoir of antimicrobial resistance contributing to the spread of resistance genes to other pathogenic Streptococcus species. In addition to serotype 2 (SS2), serotype 9 (SS9) is another prevalent serotype isolated from diseased pigs. Although many SS strains have been sequenced, the complete genome of a non-SS2 virulent strain has been unavailable to date. Here, we report the complete genome of GZ0565, a virulent strain of SS9, isolated from a pig with meningitis. Comparative genomic analysis revealed five new putative virulence or antimicrobial resistance-associated genes in strain GZ0565 but not in SS2 virulent strains. These five genes encode a putative triacylglycerol lipase, a TipAS antibiotic-recognition domain protein, a putative TetR family transcriptional repressor, a protein containing a LPXTG domain and a G5 domain, and a type VII secretion system (T7SS) putative substrate (EsxA), respectively. Western blot analysis showed that strain GZ0565 can secrete EsxA. We generated an esxA deletion mutant and showed that EsxA contributes to SS virulence in a mouse infection model. Additionally, the antibiotic resistance gene vanZSS was identified and expression of vanZSS conferred resistance to teicoplanin and dalbavancin in Streptococcus agalactiae. We believe this is the first experimental demonstration of the existence of the T7SS putative substrate EsxA and its contribution to bacterial virulence in SS. Together, our results contribute to further understanding of the virulence and antimicrobial resistance characteristics of SS.
Collapse
|
90
|
Deciphering the mode of action of cell wall-inhibiting antibiotics using metabolic labeling of growing peptidoglycan in Streptococcus pyogenes. Sci Rep 2017; 7:1129. [PMID: 28442740 PMCID: PMC5430839 DOI: 10.1038/s41598-017-01267-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/28/2017] [Indexed: 02/02/2023] Open
Abstract
Because of the scanty pipeline of antibiotics newly obtained from nature, chemical modification of established drugs is one of the major streams of current antibacterial research. Intuitive and easy-to-use assays are critical for identifying drug candidates with novel modes of action. In this study, we demonstrated that metabolic fluorescent staining of growing cell walls is a powerful tool for mode-of-action analyses of antibiotics using Streptococcus pyogenes. A set of major cell-wall-inhibiting antibiotics (bacitracin, D-cycloserine, flavomycin, oxacillin, ramoplanin, and vancomycin) was employed to validate the potential of the assay. The mechanistic differences of these antibiotics were successfully observed. For instance, D-cycloserine treatment induced fluorescently stained, excessive peripheral cell wall growth. This may indicate that the switch from the peripheral growth stage to the succeeding septal growth was disturbed by the treatment. We then applied this assay to analyze a series of vancomycin derivatives. The assay was sufficiently sensitive to detect the effects of single-site chemical modification of vancomycin on its modes of action. This metabolic fluorescent labeling method is easy to perform, especially because it does not require radiolabeled substrates. Thus, it is suitable for the preliminary evaluation of antibacterial mechanisms during antibacterial research.
Collapse
|
91
|
Venter H, Henningsen ML, Begg SL. Antimicrobial resistance in healthcare, agriculture and the environment: the biochemistry behind the headlines. Essays Biochem 2017; 61:1-10. [PMID: 28258225 PMCID: PMC5900547 DOI: 10.1042/ebc20160053] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 12/29/2022]
Abstract
The crisis of antimicrobial resistance (AMR) is one of the most serious issues facing us today. The scale of the problem is illustrated by the recent commitment of Heads of State at the UN to coordinate efforts to curb the spread of AMR infections. In this review, we explore the biochemistry behind the headlines of a few stories that were recently published in the public media. We focus on examples from three different issues related to AMR: (i) hospital-acquired infections, (ii) the spread of resistance through animals and/or the environment and (iii) the role of antimicrobial soaps and other products containing disinfectants in the dissemination of AMR. Although these stories stem from three very different settings, the underlying message in all of them is the same: there is a direct relationship between the use of antimicrobials and the development of resistance. In addition, one type of antimicrobial could select for cross-resistance to another type and/or for multidrug resistance. Therefore, we argue the case for increased stewardship to not only cover clinical use of antibiotics, but also the use of antimicrobials in agriculture and stewardship of our crucially important biocides such as chlorhexidine.
Collapse
Affiliation(s)
- Henrietta Venter
- School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5000, Australia
| | - Michael L Henningsen
- School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5000, Australia
| | - Stephanie L Begg
- School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5000, Australia
| |
Collapse
|