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Rudzite M, O’Toole GA. An energy coupling factor transporter of Streptococcus sanguinis impacts antibiotic susceptibility as well as metal and membrane homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.12.603315. [PMID: 39026867 PMCID: PMC11257530 DOI: 10.1101/2024.07.12.603315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Streptococcus sanguinis is a prevalent member of human microbiome capable of acting as a causative agent of oral and respiratory infections. S. sanguinis competitive success within the infection niche is dependent on acquisition of metal ions and vitamins. Among the systems that bacteria use for micronutrient uptake is the energy coupling factor (ECF) transporter system EcfAAT. Here we describe physiological changes arising from EcfAAT transporter disruption. We found that EcfAAT contributes to S. sanguinis antibiotic sensitivity as well as metal and membrane homeostasis. Specifically, our work found that disruption of EcfAAT results in increased polymyxin susceptibility. We performed assessment of cell-associated metal content and found depletion of iron, magnesium, and manganese. Furthermore, membrane composition analysis revealed significant enrichment in unsaturated fatty acid species resulting in increased membrane fluidity. Our results demonstrate how disruption of a single EcfAAT transporter can have broad consequences on bacterial cell homeostasis. ECF transporters are of interest within the context of infection biology in bacterial species other than streptococci, hence work described here will further the understanding of how micronutrient uptake systems contribute to bacterial pathogenesis.
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Affiliation(s)
- Marta Rudzite
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - G. A. O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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2
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Lacroix M, Moreau J, Zampaloni C, Bissantz C, Shirvani H, Marchand S, Couet W, Chauzy A. Impact of nutritional factors on in vitro PK/PD modelling of polymyxin B against various strains of Acinetobacter baumannii. Int J Antimicrob Agents 2024; 64:107189. [PMID: 38697578 DOI: 10.1016/j.ijantimicag.2024.107189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 04/23/2024] [Accepted: 04/25/2024] [Indexed: 05/05/2024]
Abstract
The main objective of this study was to assess the effect of rich artificial cation-adjusted Mueller-Hinton broth (CAMHB) on the growth of three strains of Acinetobacter baumannii (ATCC 19606 and two clinical strains), either susceptible or resistant to polymyxin B (PMB), and on PMB bactericidal activity. A pharmacokinetic (PK)/pharmacodynamic (PD) modelling approach was used to characterize the effect of PMB in various conditions. Time-kill experiments were performed using undiluted CAMHB or CAMHB diluted to 50%, 25% and 10%, with or without Ca2+ and Mg2+ compensation (known to affect PMB activity), and with PMB concentrations ranging from 0.25 to 256 mg/L based on the strain's MIC. For each strain, time-kill replicates were modelled using NONMEM. Unexpectedly, dilution of CAMHB by up to 10-fold did not affect the growth rate of any of the three strains in the absence of PMB. However, the bactericidal activity of PMB increased with medium dilution, resulting in a reduction in the apparent bacterial regrowth of the various strains observed after a few hours. Data for each strain were well characterized by a PK/PD model, with two bacterial subpopulations with different susceptibility to PMB (more susceptible and less susceptible). The impact of medium dilution and cation compensation showed relatively high, unexplained between-strain variability. Further studies are needed to characterize the mechanism underlying the medium dilution effect.
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Affiliation(s)
- Mathilde Lacroix
- Université de Poitiers, INSERM U1070, PHAR2, Poitiers, France; Institut Roche, Boulogne-Billancourt, France
| | - Jérémy Moreau
- Université de Poitiers, INSERM U1070, PHAR2, Poitiers, France
| | - Claudia Zampaloni
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Centre Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Caterina Bissantz
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Centre Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | | | - Sandrine Marchand
- Université de Poitiers, INSERM U1070, PHAR2, Poitiers, France; Département de Pharmacocinétique et Toxicologie, CHU Poitiers, Poitiers, France
| | - William Couet
- Université de Poitiers, INSERM U1070, PHAR2, Poitiers, France; Département de Pharmacocinétique et Toxicologie, CHU Poitiers, Poitiers, France
| | - Alexia Chauzy
- Université de Poitiers, INSERM U1070, PHAR2, Poitiers, France.
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3
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Buchholz KR, Reichelt M, Johnson MC, Robinson SJ, Smith PA, Rutherford ST, Quinn JG. Potent activity of polymyxin B is associated with long-lived super-stoichiometric accumulation mediated by weak-affinity binding to lipid A. Nat Commun 2024; 15:4733. [PMID: 38830951 PMCID: PMC11148078 DOI: 10.1038/s41467-024-49200-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/23/2024] [Indexed: 06/05/2024] Open
Abstract
Polymyxins are gram-negative antibiotics that target lipid A, the conserved membrane anchor of lipopolysaccharide in the outer membrane. Despite their clinical importance, the molecular mechanisms underpinning polymyxin activity remain unresolved. Here, we use surface plasmon resonance to kinetically interrogate interactions between polymyxins and lipid A and derive a phenomenological model. Our analyses suggest a lipid A-catalyzed, three-state mechanism for polymyxins: transient binding, membrane insertion, and super-stoichiometric cluster accumulation with a long residence time. Accumulation also occurs for brevicidine, another lipid A-targeting antibacterial molecule. Lipid A modifications that impart polymyxin resistance and a non-bactericidal polymyxin derivative exhibit binding that does not evolve into long-lived species. We propose that transient binding to lipid A permeabilizes the outer membrane and cluster accumulation enables the bactericidal activity of polymyxins. These findings could establish a blueprint for discovery of lipid A-targeting antibiotics and provide a generalizable approach to study interactions with the gram-negative outer membrane.
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Affiliation(s)
- Kerry R Buchholz
- Department of Infectious Diseases, Genentech, Inc., South San Francisco, CA, USA.
| | - Mike Reichelt
- Department of Pathology, Genentech, Inc., South San Francisco, CA, USA
| | - Matthew C Johnson
- Department of Structural Biology, Genentech, Inc., South San Francisco, CA, USA
| | - Sarah J Robinson
- Department of Discovery Chemistry, Genentech, Inc., South San Francisco, CA, USA
| | - Peter A Smith
- Department of Infectious Diseases, Genentech, Inc., South San Francisco, CA, USA
- Revagenix, Inc., San Mateo, CA, USA
| | - Steven T Rutherford
- Department of Infectious Diseases, Genentech, Inc., South San Francisco, CA, USA.
| | - John G Quinn
- Department of Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA, USA.
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4
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Padhy I, Dwibedy SK, Mohapatra SS. A molecular overview of the polymyxin-LPS interaction in the context of its mode of action and resistance development. Microbiol Res 2024; 283:127679. [PMID: 38508087 DOI: 10.1016/j.micres.2024.127679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 03/03/2024] [Accepted: 03/06/2024] [Indexed: 03/22/2024]
Abstract
With the rising incidences of antimicrobial resistance (AMR) and the diminishing options of novel antimicrobial agents, it is paramount to decipher the molecular mechanisms of action and the emergence of resistance to the existing drugs. Polymyxin, a cationic antimicrobial lipopeptide, is used to treat infections by Gram-negative bacterial pathogens as a last option. Though polymyxins were identified almost seventy years back, their use has been restricted owing to toxicity issues in humans. However, their clinical use has been increasing in recent times resulting in the rise of polymyxin resistance. Moreover, the detection of "mobile colistin resistance (mcr)" genes in the environment and their spread across the globe have complicated the scenario. The mechanism of polymyxin action and the development of resistance is not thoroughly understood. Specifically, the polymyxin-bacterial lipopolysaccharide (LPS) interaction is a challenging area of investigation. The use of advanced biophysical techniques and improvement in molecular dynamics simulation approaches have furthered our understanding of this interaction, which will help develop polymyxin analogs with better bactericidal effects and lesser toxicity in the future. In this review, we have delved deeper into the mechanisms of polymyxin-LPS interactions, highlighting several models proposed, and the mechanisms of polymyxin resistance development in some of the most critical Gram-negative pathogens.
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Affiliation(s)
- Indira Padhy
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India
| | - Sambit K Dwibedy
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India
| | - Saswat S Mohapatra
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India.
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5
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He S, Deber CM. Interaction of designed cationic antimicrobial peptides with the outer membrane of gram-negative bacteria. Sci Rep 2024; 14:1894. [PMID: 38253659 PMCID: PMC10803810 DOI: 10.1038/s41598-024-51716-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
The outer membrane (OM) is a hallmark feature of gram-negative bacteria that provides the species with heightened resistance against antibiotic threats while cationic antimicrobial peptides (CAPs) are natural antibiotics broadly recognized for their ability to disrupt bacterial membranes. It has been well-established that lipopolysaccharides present on the OM are among major targets of CAP activity against gram-negative species. Here we investigate how the relative distribution of charged residues along the primary peptide sequence, in conjunction with its overall hydrophobicity, affects such peptide-OM interactions in the natural CAP Ponericin W1. Using a designed peptide library derived from Ponericin W1, we determined that the consecutive placement of Lys residues at the peptide N- or C-terminus (ex. "PonN": KKKKKKWLGSALIGALLPSVVGLFQ) enhances peptide binding affinity to OM lipopolysaccharides compared to constructs where Lys residues are interspersed throughout the primary sequence (ex. "PonAmp": WLKKALKIGAKLLPSVVKLFKGSGQ). Antimicrobial activity against multidrug resistant strains of Pseudomonas aeruginosa was similarly found to be highest among Lys-clustered sequences. Our findings suggest that while native Ponericin W1 exerts its initial activity at the OM, Lys-clustering may be a promising means to enhance potency towards this interface, thereby augmenting peptide entry and activity at the IM, with apparent advantage against multidrug-resistant species.
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Affiliation(s)
- Shelley He
- Program in Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
| | - Charles M Deber
- Program in Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada.
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6
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Suchi SA, Lee DY, Kim YK, Kang SS, Bilkis T, Yoo JC. Synergistic Effect, Improved Cell Selectivity, and Elucidating the Action Mechanism of Antimicrobial Peptide YS12. Int J Mol Sci 2023; 24:13522. [PMID: 37686328 PMCID: PMC10487915 DOI: 10.3390/ijms241713522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/15/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
Antimicrobial peptides (AMPs) have attracted considerable attention as potential substitutes for traditional antibiotics. In our previous research, a novel antimicrobial peptide YS12 derived from the Bacillus velezensis strain showed broad-spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria. In this study, the fractional inhibitory concentration index (FICI) indicated that combining YS12 with commercial antibiotics produced a synergistic effect. Following these findings, the combination of YS12 with an antibiotic resulted in a faster killing effect against bacterial strains compared to the treatment with the peptide YS12 or antibiotic alone. The peptide YS12 maintained its antimicrobial activity under different physiological salts (Na+, Mg2+, and Fe3+). Most importantly, YS12 exhibited no cytotoxicity towards Raw 264.7 cells and showed low hemolytic activity, whereas positive control melittin indicated extremely high toxicity. In terms of mode of action, we found that peptide YS12 was able to bind with LPS through electrostatic interaction. The results from fluorescent measurement revealed that peptide YS12 damaged the integrity of the bacterial membrane. Confocal laser microscopy further confirmed that the localization of peptide YS12 was almost in the cytoplasm of the cells. Peptide YS12 also exhibited anti-inflammatory activity by reducing the release of LPS-induced pro-inflammatory mediators such as TNF-α, IL-1β, and NO. Collectively, these properties strongly suggest that the antimicrobial peptide YS12 may be a promising candidate for treating microbial infections and inflammation.
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Affiliation(s)
- Suzia Aktar Suchi
- Department of Pharmacy, College of Pharmacy, Chosun University, Gwangju 61452, Republic of Korea
| | - Dae Young Lee
- Department of Herbal Crop Research, National Institute of Horticultural and Herbal Science, RDA, Eumseong 27709, Republic of Korea
| | - Young Kyun Kim
- Department of Pharmacy, College of Pharmacy, Chosun University, Gwangju 61452, Republic of Korea
| | - Seong Soo Kang
- Department of Veterinary Medicine and BK21 Four Program, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Tahmina Bilkis
- Department of Biomedical Sciences, Chosun University, Gwangju 61452, Republic of Korea
| | - Jin Cheol Yoo
- Department of Pharmacy, College of Pharmacy, Chosun University, Gwangju 61452, Republic of Korea
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Thapa HB, Ebenberger SP, Schild S. The Two Faces of Bacterial Membrane Vesicles: Pathophysiological Roles and Therapeutic Opportunities. Antibiotics (Basel) 2023; 12:1045. [PMID: 37370364 PMCID: PMC10295235 DOI: 10.3390/antibiotics12061045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
Bacterial membrane vesicles (MVs) are nanosized lipid particles secreted by lysis or blebbing mechanisms from Gram-negative and -positive bacteria. It is becoming increasingly evident that MVs can promote antimicrobial resistance but also provide versatile opportunities for therapeutic exploitation. As non-living facsimiles of parent bacteria, MVs can carry multiple bioactive molecules such as proteins, lipids, nucleic acids, and metabolites, which enable them to participate in intra- and interspecific communication. Although energetically costly, the release of MVs seems beneficial for bacterial fitness, especially for pathogens. In this review, we briefly discuss the current understanding of diverse MV biogenesis routes affecting MV cargo. We comprehensively highlight the physiological functions of MVs derived from human pathogens covering in vivo adaptation, colonization fitness, and effector delivery. Emphasis is given to recent findings suggesting a vicious cycle of MV biogenesis, pathophysiological function, and antibiotic therapy. We also summarize potential therapeutical applications, such as immunotherapy, vaccination, targeted delivery, and antimicrobial potency, including their experimental validation. This comparative overview identifies common and unique strategies for MV modification used along diverse applications. Thus, the review summarizes timely aspects of MV biology in a so far unprecedented combination ranging from beneficial function for bacterial pathogen survival to future medical applications.
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Affiliation(s)
- Himadri B. Thapa
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Stephan P. Ebenberger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
- Field of Excellence Biohealth, University of Graz, 8010 Graz, Austria
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Jiao Y, Yan J, Vicchiarelli M, Sutaria DS, Lu P, Reyna Z, Spellberg B, Bonomo RA, Drusano GL, Louie A, Luna BM, Bulitta JB. Individual Components of Polymyxin B Modeled via Population Pharmacokinetics to Design Humanized Dosage Regimens for a Bloodstream and Lung Infection Model in Immune-Competent Mice. Antimicrob Agents Chemother 2023; 67:e0019723. [PMID: 37022153 PMCID: PMC10190254 DOI: 10.1128/aac.00197-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 03/20/2023] [Indexed: 04/07/2023] Open
Abstract
Polymyxin B is a "last-line-of-defense" antibiotic approved in the 1960s. However, the population pharmacokinetics (PK) of its four main components has not been reported in infected mice. We aimed to determine the PK of polymyxin B1, B1-Ile, B2, and B3 in a murine bloodstream and lung infection model of Acinetobacter baumannii and develop humanized dosage regimens. A linear 1-compartment model, plus an epithelial lining fluid (ELF) compartment for the lung model, best described the PK. Clearance and volume of distribution were similar among the four components. The bioavailability fractions were 72.6% for polymyxin B1, 12.0% for B1-Ile, 11.5% for B2, and 3.81% for B3 for the lung model and were similar for the bloodstream model. While the volume of distribution was comparable between both models (17.3 mL for the lung and ~27 mL for the bloodstream model), clearance was considerably smaller for the lung (2.85 mL/h) compared to that of the bloodstream model (5.59 mL/h). The total drug exposure (AUC) in ELF was high due to the saturable binding of polymyxin B presumably to bacterial lipopolysaccharides. However, the modeled unbound AUC in ELF was ~16.7% compared to the total drug AUC in plasma. The long elimination half-life (~4 h) of polymyxin B enabled humanized dosage regimens with every 12 h dosing in mice. Daily doses that optimally matched the range of drug concentrations observed in patients were 21 mg/kg for the bloodstream and 13 mg/kg for the lung model. These dosage regimens and population PK models support translational studies for polymyxin B at clinically relevant drug exposures.
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Affiliation(s)
- Yuanyuan Jiao
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Jun Yan
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Michael Vicchiarelli
- Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, USA
| | - Dhruvitkumar S. Sutaria
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Peggy Lu
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Zeferino Reyna
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Brad Spellberg
- Los Angeles County-USC (LAC+USC) Medical Center, Los Angeles, California, USA
| | - Robert A. Bonomo
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, USA
- Deparment of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA
- Deparment of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, Ohio, USA
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
| | - George L. Drusano
- Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, USA
| | - Arnold Louie
- Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, USA
| | - Brian M. Luna
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Jürgen B. Bulitta
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
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Ramôa AM, Campos F, Moreira L, Teixeira C, Leiro V, Gomes P, das Neves J, Martins MCL, Monteiro C. Antimicrobial peptide-grafted PLGA-PEG nanoparticles to fight bacterial wound infections. Biomater Sci 2023; 11:499-508. [PMID: 36458466 DOI: 10.1039/d2bm01127a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Wound infection treatment with antimicrobial peptides (AMPs) is still not a reality, due to the loss of activity in vivo. Unlike the conventional strategy of encapsulating AMPs on nanoparticles (NPs) leaving activity dependent on the release profile, this work explores AMP grafting to poly(D,L-lactide-co-glycolide)-polyethylene glycol NPs (PLGA-PEG NPs), whereby AMP exposition, infection targeting and immediate action are promoted. NPs are functionalized with MSI-78(4-20), an equipotent and more selective derivative of MSI-78, grafted through a thiol-maleimide (Mal) Michael addition. NPs with different ratios of PLGA-PEG/PLGA-PEG-Mal are produced and characterized, with 40%PLGA-PEG-Mal presenting the best colloidal properties and higher amounts of AMP grafted as shown by surface charge (+8.6 ± 1.8 mV) and AMP quantification (326 μg mL-1, corresponding to 16.3 μg of AMP per mg of polymer). NPs maintain the activity of the free AMP with a minimal inhibitory concentration (MIC) of 8-16 μg mL-1 against Pseudomonas aeruginosa, and 16-32 μg mL-1 against Staphylococcus aureus. Moreover, AMP grafting accelerates killing kinetics, from 1-2 h to 15 min for P. aeruginosa and from 6-8 h to 0.5-1 h for S. aureus. NP activity in a simulated wound fluid is maintained for S. aureus and decreases slightly for P. aeruginosa. Furthermore, NPs do not demonstrate signs of cytotoxicity at MIC concentrations. Overall, this promising formulation helps unleash the full potential of AMPs for the management of wound infections.
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Affiliation(s)
- António Miguel Ramôa
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. .,INEB, Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.,Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.,Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal
| | - Filipa Campos
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. .,INEB, Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Luís Moreira
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. .,INEB, Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.,Escola Superior de Biotecnologia, Universidade Católica do Porto, Rua de Diogo Botelho, 1327, 4169-005 Porto, Portugal
| | - Cátia Teixeira
- LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Victoria Leiro
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. .,INEB, Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Paula Gomes
- LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - José das Neves
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. .,INEB, Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - M Cristina L Martins
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. .,INEB, Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.,Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Cláudia Monteiro
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal. .,INEB, Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
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10
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Schink S, Ammar C, Chang Y, Zimmer R, Basan M. Analysis of proteome adaptation reveals a key role of the bacterial envelope in starvation survival. Mol Syst Biol 2022; 18:e11160. [PMID: 36479616 PMCID: PMC9728487 DOI: 10.15252/msb.202211160] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 12/12/2022] Open
Abstract
Bacteria reorganize their physiology upon entry to stationary phase. What part of this reorganization improves starvation survival is a difficult question because the change in physiology includes a global reorganization of the proteome, envelope, and metabolism of the cell. In this work, we used several trade-offs between fast growth and long survival to statistically score over 2,000 Escherichia coli proteins for their global correlation with death rate. The combined ranking allowed us to narrow down the set of proteins that positively correlate with survival and validate the causal role of a subset of proteins. Remarkably, we found that important survival genes are related to the cell envelope, i.e., periplasm and outer membrane, because the maintenance of envelope integrity of E. coli plays a crucial role during starvation. Our results uncover a new protective feature of the outer membrane that adds to the growing evidence that the outer membrane is not only a barrier that prevents abiotic substances from reaching the cytoplasm but also essential for bacterial proliferation and survival.
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Affiliation(s)
- Severin Schink
- Systems Biology DepartmentHarvard Medical SchoolMABostonUSA
| | - Constantin Ammar
- Systems Biology DepartmentHarvard Medical SchoolMABostonUSA
- Institute of InformaticsLudwig‐Maximilians‐Universität MünchenMunichGermany
- Department of Proteomics and Signal TransductionMax Planck Institute of BiochemistryMartinsriedGermany
| | - Yu‐Fang Chang
- Systems Biology DepartmentHarvard Medical SchoolMABostonUSA
| | - Ralf Zimmer
- Institute of InformaticsLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Markus Basan
- Systems Biology DepartmentHarvard Medical SchoolMABostonUSA
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11
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Koh Jing Jie A, Hussein M, Rao GG, Li J, Velkov T. Drug Repurposing Approaches towards Defeating Multidrug-Resistant Gram-Negative Pathogens: Novel Polymyxin/Non-Antibiotic Combinations. Pathogens 2022; 11:pathogens11121420. [PMID: 36558754 PMCID: PMC9781023 DOI: 10.3390/pathogens11121420] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 11/30/2022] Open
Abstract
Multidrug-resistant (MDR) Gram-negative pathogens remain an unmet public health threat. In recent times, increased rates of resistance have been reported not only to commonly used antibiotics, but also to the last-resort antibiotics, such as polymyxins. More worryingly, despite the current trends in resistance, there is a lack of new antibiotics in the drug-discovery pipeline. Hence, it is imperative that new strategies are developed to preserve the clinical efficacy of the current antibiotics, particularly the last-line agents. Combining conventional antibiotics such as polymyxins with non-antibiotics (or adjuvants), has emerged as a novel and effective strategy against otherwise untreatable MDR pathogens. This review explores the available literature detailing the latest polymyxin/non-antibiotic combinations, their mechanisms of action, and potential avenues to advance their clinical application.
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Affiliation(s)
- Augustine Koh Jing Jie
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Maytham Hussein
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Gauri G. Rao
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jian Li
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Tony Velkov
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
- Correspondence:
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12
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Meir O, Zaknoon F, Mor A. An efflux-susceptible antibiotic-adjuvant with systemic efficacy against mouse infections. Sci Rep 2022; 12:17673. [PMID: 36271103 PMCID: PMC9586926 DOI: 10.1038/s41598-022-21526-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 09/28/2022] [Indexed: 01/18/2023] Open
Abstract
Scarcity of effective treatments against sepsis is daunting, especially under the contemporary standpoints on antibiotics resistance, entailing the development of alternative treatment strategies. Here, we describe the design and antibiotic adjuvant properties of a new lipopeptide-like pentamer, decanoyl-bis.diaminobutyrate-aminododecanoyl-diaminobutyrate-amide (C10BBc12B), whose sub-maximal tolerated doses combinations with inefficient antibiotics demonstrated systemic efficacies in murine models of peritonitis-sepsis and urinary-tract infections. Attempts to shed light into the mechanism of action using membrane-active fluorescent probes, suggest outer-membrane interactions to dominate the pentamer's adjuvant properties, which were not associated with typical inner-membrane damages or with delayed bacterial growth. Yet, checkerboard titrations with low micromolar concentrations of C10BBc12B exhibited unprecedented capacities in potentiation of hydrophobic antibiotics towards Gram-negative ESKAPE pathogens, with an apparent low propensity for prompting resistance to the antibiotics. Assessment of the pentamer's potentiating activities upon efflux inhibition incites submission of a hitherto unreported, probable action mechanism implicating the pentamer's de-facto capacity to hijack bacterial efflux pumps for boosting its adjuvant activity through repetitive steps including outer-membrane adhesion, translocation and subsequent expulsion.
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Affiliation(s)
- Ohad Meir
- grid.6451.60000000121102151Faculty of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, 3200003 Haifa, Israel
| | - Fadia Zaknoon
- grid.6451.60000000121102151Faculty of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, 3200003 Haifa, Israel
| | - Amram Mor
- grid.6451.60000000121102151Faculty of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, 3200003 Haifa, Israel
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13
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Lipid Microenvironment Modulates the Pore-Forming Ability of Polymyxin B. Antibiotics (Basel) 2022; 11:antibiotics11101445. [PMID: 36290103 PMCID: PMC9598075 DOI: 10.3390/antibiotics11101445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022] Open
Abstract
The ability of polymyxin B, an antibiotic used to treat infections caused by multidrug-resistant Gram-negative bacteria as a last-line therapeutic option, to form ion pores in model membranes composed of various phospholipids and lipopolysaccharides was studied. Our data demonstrate that polymyxin B predominantly interacts with negatively charged lipids. Susceptibility decreases as follows: Kdo2-Lipid A >> DOPG ≈ DOPS >> DPhPG ≈ TOCL ≈ Lipid A. The dimer and hexamer of polymyxin B are involved in the pore formation in DOPG(DOPS)- and Kdo2-Lipid A-enriched bilayers, respectively. The pore-forming ability of polymyxin B significantly depends on the shape of membrane lipids, which indicates that the antibiotic produces toroidal lipopeptide-lipid pores. Small amphiphilic molecules diminishing the membrane dipole potential and inducing positive curvature stress were shown to be agonists of pore formation by polymyxin B and might be used to develop innovative lipopeptide-based formulations.
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14
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Wang G, Brunel JM, Preusse M, Mozaheb N, Willger SD, Larrouy-Maumus G, Baatsen P, Häussler S, Bolla JM, Van Bambeke F. The membrane-active polyaminoisoprenyl compound NV716 re-sensitizes Pseudomonas aeruginosa to antibiotics and reduces bacterial virulence. Commun Biol 2022; 5:871. [PMID: 36008485 PMCID: PMC9411590 DOI: 10.1038/s42003-022-03836-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 08/11/2022] [Indexed: 11/09/2022] Open
Abstract
Pseudomonas aeruginosa is intrinsically resistant to many antibiotics due to the impermeability of its outer membrane and to the constitutive expression of efflux pumps. Here, we show that the polyaminoisoprenyl compound NV716 at sub-MIC concentrations re-sensitizes P. aeruginosa to abandoned antibiotics by binding to the lipopolysaccharides (LPS) of the outer membrane, permeabilizing this membrane and increasing antibiotic accumulation inside the bacteria. It also prevents selection of resistance to antibiotics and increases their activity against biofilms. No stable resistance could be selected to NV716-itself after serial passages with subinhibitory concentrations, but the transcriptome of the resulting daughter cells shows an upregulation of genes involved in the synthesis of lipid A and LPS, and a downregulation of quorum sensing-related genes. Accordingly, NV716 also reduces motility, virulence factors production, and biofilm formation. NV716 shows a unique and highly promising profile of activity when used alone or in combination with antibiotics against P. aeruginosa, combining in a single molecule anti-virulence and potentiator effects. Additional work is required to more thoroughly understand the various functions of NV716. The polyaminoisoprenyl compound NV716 re-sensitizes Pseudomonas aeruginosa to antibiotics through permeabilizing the outer membrane and increases the activity of antibiotics on biofilms.
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Affiliation(s)
- Gang Wang
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jean-Michel Brunel
- Aix Marseille Université, INSERM, SSA, Membranes et Cibles thérapeutiques (MCT), Marseille, France
| | - Matthias Preusse
- Department of Molecular Bacteriology, Helmoltz Centre for Infection Research, Braunschweig, Germany
| | - Negar Mozaheb
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Sven D Willger
- Department of Molecular Bacteriology, Helmoltz Centre for Infection Research, Braunschweig, Germany.,Department of Molecular Bacteriology, Twincore, Hannover, Germany.,Institute for Medical Biometry and Bioinformatics, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Gerald Larrouy-Maumus
- Department of Life Sciences, Faculty of Natural Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Pieter Baatsen
- Electron Microscopy Platform & Bio Imaging Core, VIB & KULeuven Center for Brain & Disease Research, KULeuven, Leuven, Belgium
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmoltz Centre for Infection Research, Braunschweig, Germany.,Department of Molecular Bacteriology, Twincore, Hannover, Germany.,Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.,Cluster of Excellence RESIST, Hannover Medical School, Hannover, Germany
| | - Jean-Michel Bolla
- Aix Marseille Université, INSERM, SSA, Membranes et Cibles thérapeutiques (MCT), Marseille, France
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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15
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A method for increasing electroporation competence of Gram-negative clinical isolates by polymyxin B nonapeptide. Sci Rep 2022; 12:11629. [PMID: 35804085 PMCID: PMC9270391 DOI: 10.1038/s41598-022-15997-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 07/04/2022] [Indexed: 11/09/2022] Open
Abstract
The study of clinically relevant bacterial pathogens relies on molecular and genetic approaches. However, the generally low transformation frequency among natural isolates poses technical hurdles to widely applying common methods in molecular biology, including transformation of large constructs, chromosomal genetic manipulation, and dense mutant library construction. Here we demonstrate that culturing clinical isolates in the presence of polymyxin B nonapeptide (PMBN) improves their transformation frequency via electroporation by up to 100-fold in a dose-dependent and reversible manner. The effect was observed for PMBN-binding uropathogenic Escherichia coli (UPEC) and Salmonella enterica strains but not naturally polymyxin resistant Proteus mirabilis. Using our PMBN electroporation method we show efficient delivery of large plasmid constructs into UPEC, which otherwise failed using a conventional electroporation protocol. Moreover, we show a fivefold increase in the yield of engineered mutant colonies obtained in S. enterica with the widely used lambda-Red recombineering method, when cells are cultured in the presence of PMBN. Lastly, we demonstrate that PMBN treatment can enhance the delivery of DNA-transposase complexes into UPEC and increase transposon mutant yield by eightfold when constructing Transposon Insertion Sequencing (TIS) libraries. Therefore, PMBN can be used as a powerful electropermeabilisation adjuvant to aid the delivery of DNA and DNA-protein complexes into clinically important bacteria.
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16
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Marciano DC, Wang C, Hsu TK, Bourquard T, Atri B, Nehring RB, Abel NS, Bowling EA, Chen TJ, Lurie PD, Katsonis P, Rosenberg SM, Herman C, Lichtarge O. Evolutionary action of mutations reveals antimicrobial resistance genes in Escherichia coli. Nat Commun 2022; 13:3189. [PMID: 35680894 PMCID: PMC9184624 DOI: 10.1038/s41467-022-30889-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 05/24/2022] [Indexed: 11/08/2022] Open
Abstract
Since antibiotic development lags, we search for potential drug targets through directed evolution experiments. A challenge is that many resistance genes hide in a noisy mutational background as mutator clones emerge in the adaptive population. Here, to overcome this noise, we quantify the impact of mutations through evolutionary action (EA). After sequencing ciprofloxacin or colistin resistance strains grown under different mutational regimes, we find that an elevated sum of the evolutionary action of mutations in a gene identifies known resistance drivers. This EA integration approach also suggests new antibiotic resistance genes which are then shown to provide a fitness advantage in competition experiments. Moreover, EA integration analysis of clinical and environmental isolates of antibiotic resistant of E. coli identifies gene drivers of resistance where a standard approach fails. Together these results inform the genetic basis of de novo colistin resistance and support the robust discovery of phenotype-driving genes via the evolutionary action of genetic perturbations in fitness landscapes.
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Affiliation(s)
- David C Marciano
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Chen Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Teng-Kuei Hsu
- The Verna and Marrs McLean Department of Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Thomas Bourquard
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Benu Atri
- Structural and Computational Biology & Molecular Biophysics Program, Baylor College of Medicine, Houston, TX, 77030, USA
- Clara Analytics Inc., 451 El Camino Real #201, Santa Clara, CA, 95050, USA
| | - Ralf B Nehring
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- The Verna and Marrs McLean Department of Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Nicholas S Abel
- Department of Pharmacology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Elizabeth A Bowling
- The Verna and Marrs McLean Department of Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Taylor J Chen
- Integrative Molecular & Biomedical Biosciences Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Pamela D Lurie
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Panagiotis Katsonis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- The Verna and Marrs McLean Department of Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
- Integrative Molecular & Biomedical Biosciences Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Christophe Herman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Olivier Lichtarge
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Structural and Computational Biology & Molecular Biophysics Program, Baylor College of Medicine, Houston, TX, 77030, USA.
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA.
- Computational and Integrative Biomedical Research Center, Baylor College of Medicine, Houston, TX, 77030, USA.
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17
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Milicaj J, Hassan BA, Cote JM, Ramirez-Mondragon CA, Jaunbocus N, Rafalowski A, Patel KR, Castro CD, Muthyala R, Sham YY, Taylor EA. Discovery of first-in-class nanomolar inhibitors of heptosyltransferase I reveals a new aminoglycoside target and potential alternative mechanism of action. Sci Rep 2022; 12:7302. [PMID: 35508636 PMCID: PMC9068772 DOI: 10.1038/s41598-022-10776-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 04/04/2022] [Indexed: 11/08/2022] Open
Abstract
A clinically relevant inhibitor for Heptosyltransferase I (HepI) has been sought after for many years because of its critical role in the biosynthesis of lipopolysaccharides on bacterial cell surfaces. While many labs have discovered or designed novel small molecule inhibitors, these compounds lacked the bioavailability and potency necessary for therapeutic use. Extensive characterization of the HepI protein has provided valuable insight into the dynamic motions necessary for catalysis that could be targeted for inhibition. Structural inspection of Kdo2-lipid A suggested aminoglycoside antibiotics as potential inhibitors for HepI. Multiple aminoglycosides have been experimentally validated to be first-in-class nanomolar inhibitors of HepI, with the best inhibitor demonstrating a Ki of 600 ± 90 nM. Detailed kinetic analyses were performed to determine the mechanism of inhibition while circular dichroism spectroscopy, intrinsic tryptophan fluorescence, docking, and molecular dynamics simulations were used to corroborate kinetic experimental findings. While aminoglycosides have long been described as potent antibiotics targeting bacterial ribosomes' protein synthesis leading to disruption of the stability of bacterial cell membranes, more recently researchers have shown that they only modestly impact protein production. Our research suggests an alternative and novel mechanism of action of aminoglycosides in the inhibition of HepI, which directly leads to modification of LPS production in vivo. This finding could change our understanding of how aminoglycoside antibiotics function, with interruption of LPS biosynthesis being an additional and important mechanism of aminoglycoside action. Further research to discern the microbiological impact of aminoglycosides on cells is warranted, as inhibition of the ribosome may not be the sole and primary mechanism of action. The inhibition of HepI by aminoglycosides may dramatically alter strategies to modify the structure of aminoglycosides to improve the efficacy in fighting bacterial infections.
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Affiliation(s)
- Jozafina Milicaj
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, USA
| | - Bakar A Hassan
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, USA
| | - Joy M Cote
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, USA
| | | | - Nadiya Jaunbocus
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, USA
| | | | - Kaelan R Patel
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Colleen D Castro
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, USA
| | - Ramaiah Muthyala
- Department of Experimental and Clinical Pharmacology, College Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Yuk Y Sham
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55455, USA.
- Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, MN, 55455, USA.
| | - Erika A Taylor
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, USA.
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18
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Ledger EVK, Sabnis A, Edwards AM. Polymyxin and lipopeptide antibiotics: membrane-targeting drugs of last resort. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001136. [PMID: 35118938 PMCID: PMC8941995 DOI: 10.1099/mic.0.001136] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/06/2022] [Indexed: 12/15/2022]
Abstract
The polymyxin and lipopeptide classes of antibiotics are membrane-targeting drugs of last resort used to treat infections caused by multi-drug-resistant pathogens. Despite similar structures, these two antibiotic classes have distinct modes of action and clinical uses. The polymyxins target lipopolysaccharide in the membranes of most Gram-negative species and are often used to treat infections caused by carbapenem-resistant species such as Escherichia coli, Acinetobacter baumannii and Pseudomonas aeruginosa. By contrast, the lipopeptide daptomycin requires membrane phosphatidylglycerol for activity and is only used to treat infections caused by drug-resistant Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. However, despite having distinct targets, both antibiotic classes cause membrane disruption, are potently bactericidal in vitro and share similarities in resistance mechanisms. Furthermore, there are concerns about the efficacy of these antibiotics, and there is increasing interest in using both polymyxins and daptomycin in combination therapies to improve patient outcomes. In this review article, we will explore what is known about these distinct but structurally similar classes of antibiotics, discuss recent advances in the field and highlight remaining gaps in our knowledge.
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Affiliation(s)
- Elizabeth V. K. Ledger
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
| | - Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
| | - Andrew M. Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
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19
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Application of antibiotic-derived fluorescent probes to bacterial studies. Methods Enzymol 2022; 665:1-28. [DOI: 10.1016/bs.mie.2021.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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20
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Zaknoon F, Meir O, Mor A. Mechanistic Studies of Antibiotic Adjuvants Reducing Kidney's Bacterial Loads upon Systemic Monotherapy. Pharmaceutics 2021; 13:pharmaceutics13111947. [PMID: 34834362 PMCID: PMC8621570 DOI: 10.3390/pharmaceutics13111947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/11/2021] [Accepted: 11/14/2021] [Indexed: 12/01/2022] Open
Abstract
We describe the design and attributes of a linear pentapeptide-like derivative (C14(ω5)OOc10O) screened for its ability to elicit bactericidal competences of plasma constituents against Gram-negative bacteria (GNB). In simpler culture media, the lipopeptide revealed high aptitudes to sensitize resilient GNB to hydrophobic and/or efflux-substrate antibiotics, whereas in their absence, C14(ω5)OOc10O only briefly delayed bacterial proliferation. Instead, at low micromolar concentrations, the lipopeptide has rapidly lowered bacterial proton and ATP levels, although significantly less than upon treatment with its bactericidal analog. Mechanistic studies support a two-step scenario providing a plausible explanation for the lipopeptide’s biological outcomes against GNB: initially, C14(ω5)OOc10O permeabilizes the outer membrane similarly to polymyxin B, albeit in a manner not necessitating as much LPS-binding affinity. Subsequently, C14(ω5)OOc10O would interact with the inner membrane gently yet intensively enough to restrain membrane-protein functions such as drug efflux and/or ATP generation, while averting the harsher inner membrane perturbations that mediate the fatal outcome associated with bactericidal peers. Preliminary in vivo studies where skin wound infections were introduced in mice, revealed a significant efficacy in affecting bacterial viability upon topical treatment with creams containing C14(ω5)OOc10O, whereas synergistic combination therapies were able to secure the pathogen’s eradication. Further, capitalizing on the finding that C14(ω5)OOc10O plasma-potentiating concentrations were attainable in mice blood at sub-maximal tolerated doses, we used a urinary tract infection model to acquire evidence for the lipopeptide’s systemic capacity to reduce the kidney’s bacterial loads. Collectively, the data establish the role of C14(ω5)OOc10O as a compelling antibacterial potentiator and suggest its drug-like potential.
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21
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Mohamed Z, Shin JH, Ghosh S, Sharma AK, Pinnock F, Bint E Naser Farnush S, Dörr T, Daniel S. Clinically Relevant Bacterial Outer Membrane Models for Antibiotic Screening Applications. ACS Infect Dis 2021; 7:2707-2722. [PMID: 34227387 DOI: 10.1021/acsinfecdis.1c00217] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Antibiotic resistance is a growing global health concern that has been increasing in prevalence over the past few decades. In Gram-negative bacteria, the outer membrane is an additional barrier through which antibiotics must traverse to kill the bacterium. In addition, outer membrane features and properties, like membrane surface charge, lipopolysaccharide (LPS) length, and membrane porins, can be altered in response to antibiotics and therefore, further mediate resistance. Model membranes have been used to mimic bacterial membranes to study antibiotic-induced membrane changes but often lack the compositional complexity of the actual outer membrane. Here, we developed a surface-supported membrane platform using outer membrane vesicles (OMVs) from clinically relevant Gram-negative bacteria and use it to characterize membrane biophysical properties and investigate its interaction with antibacterial compounds. We demonstrate that this platform maintains critical features of outer membranes, like fluidity, while retaining complex membrane components, like OMPs and LPS, which are central to membrane-mediated antibiotic resistance. This platform offers a non-pathogenic, cell-free surface to study such phenomena that is compatible with advanced microscopy and surface characterization tools like quartz crystal microbalance. We confirm these OMV bilayers recapitulate membrane interactions (or lack thereof) with the antibiotic compounds polymyxin B, bacitracin, and vancomycin, validating their use as representative models for the bacterial surface. By forming OMV bilayers from different strains, we envision that this platform could be used to investigate underlying biophysical differences in outer membranes leading to resistance, to screen and identify membrane-active antibiotics, or for the development of phage technologies targeting a particular membrane surface component.
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Affiliation(s)
- Zeinab Mohamed
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York United States
| | - Jung-Ho Shin
- Weill Institute for Cell and Molecular Biology and Department of Microbiology, Cornell University, Ithaca, New York United States
| | - Surajit Ghosh
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York United States
| | - Abhishek K. Sharma
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York United States
| | - Ferra Pinnock
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York United States
| | - Samavi Bint E Naser Farnush
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York United States
| | - Tobias Dörr
- Weill Institute for Cell and Molecular Biology and Department of Microbiology, Cornell University, Ithaca, New York United States
| | - Susan Daniel
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York United States
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York United States
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22
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van Groesen E, Slingerland CJ, Innocenti P, Mihajlovic M, Masereeuw R, Martin NI. Vancomyxins: Vancomycin-Polymyxin Nonapeptide Conjugates That Retain Anti-Gram-Positive Activity with Enhanced Potency against Gram-Negative Strains. ACS Infect Dis 2021; 7:2746-2754. [PMID: 34387988 PMCID: PMC8438664 DOI: 10.1021/acsinfecdis.1c00318] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
![]()
Vancomycin functions
by binding to lipid II, the penultimate bacterial
cell wall building block used by both Gram-positive and Gram-negative
species. However, vancomycin is generally only able to exert its antimicrobial
effect against Gram-positive strains as it cannot pass the outer membrane
(OM) of Gram-negative bacteria. To address this challenge, we here
describe efforts to conjugate vancomycin to the OM disrupting polymyxin
E nonapeptide (PMEN) to yield the hybrid “vancomyxins”.
In designing these hybrid antibiotics, different spacers and conjugation
sites were explored for connecting vancomycin and PMEN. The vancomyxins
show improved activity against Gram-negative strains compared with
the activity of vancomycin or vancomycin supplemented with PMEN separately.
In addition, the vancomyxins maintain the antimicrobial effect of
vancomycin against Gram-positive strains and, in some cases, show
enhanced activity against vancomycin-resistant strains. The hybrid
antibiotics described here have reduced nephrotoxicity when compared
with clinically used polymyxin antibiotics. This study demonstrates
that covalent conjugation to an OM disruptor contributes to sensitizing
Gram-negative strains to vancomycin while retaining anti-Gram-positive
activity.
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Affiliation(s)
- Emma van Groesen
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Cornelis J. Slingerland
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Paolo Innocenti
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Milos Mihajlovic
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Rosalinde Masereeuw
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Nathaniel I. Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
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23
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Noden M, Taylor SD. Enantioselective Synthesis and Application of Small and Environmentally Sensitive Fluorescent Amino Acids for Probing Biological Interactions. J Org Chem 2021; 86:11407-11418. [PMID: 34387500 DOI: 10.1021/acs.joc.1c00907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Environmentally sensitive fluorescent amino acids (FlAAs) have been used extensively to probe biological interactions. However, most of these amino acids are large and do not resemble amino acid side chains. Here, we report the enantioselective synthesis of two small and environmentally sensitive fluorescent amino acids bearing 7-dialkylaminocoumarin side chains by alkylation of a Ni(II) glycine Schiff base complex. These amino acids exhibit a large increase in fluorescence as environment polarity decreases. One of these FLAAs was incorporated into a highly active analog of the cyclic lipopeptide antibiotic paenibacterin by Fmoc solid-phase peptide synthesis via a new and very efficient route. This peptide was used to probe the interaction of the antibiotic with model liposomes, lipopolysaccharides, and live bacteria.
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Affiliation(s)
- Michael Noden
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Scott D Taylor
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
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24
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Interest of Homodialkyl Neamine Derivatives against Resistant P. aeruginosa, E. coli, and β-Lactamases-Producing Bacteria-Effect of Alkyl Chain Length on the Interaction with LPS. Int J Mol Sci 2021; 22:ijms22168707. [PMID: 34445410 PMCID: PMC8396045 DOI: 10.3390/ijms22168707] [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: 06/28/2021] [Revised: 07/29/2021] [Accepted: 08/07/2021] [Indexed: 11/24/2022] Open
Abstract
Development of novel therapeutics to treat antibiotic-resistant infections, especially those caused by ESKAPE pathogens, is urgent. One of the most critical pathogens is P. aeruginosa, which is able to develop a large number of factors associated with antibiotic resistance, including high level of impermeability. Gram-negative bacteria are protected from the environment by an asymmetric Outer Membrane primarily composed of lipopolysaccharides (LPS) at the outer leaflet and phospholipids in the inner leaflet. Based on a large hemi-synthesis program focusing on amphiphilic aminoglycoside derivatives, we extend the antimicrobial activity of 3′,6-dinonyl neamine and its branched isomer, 3′,6-di(dimethyloctyl) neamine on clinical P. aeruginosa, ESBL, and carbapenemase strains. We also investigated the capacity of 3′,6-homodialkyl neamine derivatives carrying different alkyl chains (C7–C11) to interact with LPS and alter membrane permeability. 3′,6-Dinonyl neamine and its branched isomer, 3′,6-di(dimethyloctyl) neamine showed low MICs on clinical P. aeruginosa, ESBL, and carbapenemase strains with no MIC increase for long-duration incubation. In contrast from what was observed for membrane permeability, length of alkyl chains was critical for the capacity of 3′,6-homodialkyl neamine derivatives to bind to LPS. We demonstrated the high antibacterial potential of the amphiphilic neamine derivatives in the fight against ESKAPE pathogens and pointed out some particular characteristics making the 3′,6-dinonyl- and 3′,6-di(dimethyloctyl)-neamine derivatives the best candidates for further development.
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25
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Wood TM, Slingerland CJ, Martin NI. A Convenient Chemoenzymatic Preparation of Chimeric Macrocyclic Peptide Antibiotics with Potent Activity against Gram-Negative Pathogens. J Med Chem 2021; 64:10890-10899. [PMID: 34283589 PMCID: PMC8365600 DOI: 10.1021/acs.jmedchem.1c00176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
The continuing rise
of antibiotic resistance, particularly among
Gram-negative pathogens, threatens to undermine many aspects of modern
medical practice. To address this threat, novel antibiotics that utilize
unexploited bacterial targets are urgently needed. Over the past decade,
a number of studies have highlighted the antibacterial potential of
macrocyclic peptides that target Gram-negative outer membrane proteins
(OMPs). Recently, it was reported that the antibacterial activities
of OMP-targeting macrocyclic peptidomimetics of the antimicrobial
peptide protegrin-1 are dramatically enhanced upon linking to polymyxin
E nonapeptide (PMEN). In this study, we describe a convergent, chemoenzymatic
route for the convenient preparation of such conjugates. Specifically,
we investigated the use of both amide bond formation and azide-alkyne
ligation for connecting an OMP-targeting macrocyclic peptide to a
PMEN building block (obtained by enzymatic degradation of polymyxin
E). The conjugates obtained via both approaches display potent antibacterial
activity against a range of Gram-negative pathogens including multi-drug-resistant
isolates.
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Affiliation(s)
- Thomas M Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands.,Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, The Netherlands
| | - Cornelis J Slingerland
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
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26
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Sadecki PW, Balboa SJ, Lopez LR, Kedziora KM, Arthur JC, Hicks LM. Evolution of Polymyxin Resistance Regulates Colibactin Production in Escherichia coli. ACS Chem Biol 2021; 16:1243-1254. [PMID: 34232632 PMCID: PMC8601121 DOI: 10.1021/acschembio.1c00322] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The complex reservoir of metabolite-producing bacteria in the gastrointestinal tract contributes tremendously to human health and disease. Bacterial composition, and by extension gut metabolomic composition, is undoubtably influenced by the use of modern antibiotics. Herein, we demonstrate that polymyxin B, a last resort antibiotic, influences the production of the genotoxic metabolite colibactin from adherent-invasive Escherichia coli (AIEC) NC101. Colibactin can promote colorectal cancer through DNA double stranded breaks and interstrand cross-links. While the structure and biosynthesis of colibactin have been elucidated, chemical-induced regulation of its biosynthetic gene cluster and subsequent production of the genotoxin by E. coli are largely unexplored. Using a multiomic approach, we identified that polymyxin B stress enhances the abundance of colibactin biosynthesis proteins (Clb's) in multiple pks+ E. coli strains, including pro-carcinogenic AIEC, NC101; the probiotic strain, Nissle 1917; and the antibiotic testing strain, ATCC 25922. Expression analysis via qPCR revealed that increased transcription of clb genes likely contributes to elevated Clb protein levels in NC101. Enhanced production of Clb's by NC101 under polymyxin stress matched an increased production of the colibactin prodrug motif, a proxy for the mature genotoxic metabolite. Furthermore, E. coli with a heightened tolerance for polymyxin induced greater mammalian DNA damage, assessed by quantification of γH2AX staining in cultured intestinal epithelial cells. This study establishes a key link between the polymyxin B stress response and colibactin production in pks+ E. coli. Ultimately, our findings will inform future studies investigating colibactin regulation and the ability of seemingly innocuous commensal microbes to induce host disease.
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Affiliation(s)
- Patric W. Sadecki
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Samantha J. Balboa
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Lacey R. Lopez
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Katarzyna M. Kedziora
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Bioinformatics and Analytics Research Collaborative (BARC), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Janelle C. Arthur
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Leslie M. Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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27
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Jiang X, Yang K, Yuan B, Han M, Zhu Y, Roberts KD, Patil NA, Li J, Gong B, Hancock REW, Velkov T, Schreiber F, Wang L, Li J. Molecular dynamics simulations informed by membrane lipidomics reveal the structure-interaction relationship of polymyxins with the lipid A-based outer membrane of Acinetobacter baumannii. J Antimicrob Chemother 2021; 75:3534-3543. [PMID: 32911540 DOI: 10.1093/jac/dkaa376] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 08/04/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND MDR bacteria represent an urgent threat to human health globally. Polymyxins are a last-line therapy against life-threatening Gram-negative 'superbugs', including Acinetobacter baumannii. Polymyxins exert antimicrobial activity primarily via permeabilizing the bacterial outer membrane (OM); however, the mechanism of interaction between polymyxins and the OM remains unclear at the atomic level. METHODS We constructed a lipid A-based OM model of A. baumannii using quantitative membrane lipidomics data and employed all-atom molecular dynamics simulations with umbrella sampling techniques to elucidate the structure-interaction relationship and thermodynamics governing the penetration of polymyxins [B1 and E1 (i.e. colistin A) representing the two clinically used polymyxins] into the OM. RESULTS Polymyxin B1 and colistin A bound to the A. baumannii OM by the initial electrostatic interactions between the Dab residues of polymyxins and the phosphates of lipid A, competitively displacing the cations from the headgroup region of the OM. Both polymyxin B1 and colistin A formed a unique folded conformation upon approaching the hydrophobic centre of the OM, consistent with previous experimental observations. Polymyxin penetration induced reorientation of the headgroups of the OM lipids near the penetration site and caused local membrane disorganization, thereby significantly increasing membrane permeability and promoting the subsequent penetration of polymyxin molecules into the OM and periplasmic space. CONCLUSIONS The thermodynamics governing the penetration of polymyxins through the outer leaflet of the A. baumannii OM were examined and novel structure-interaction relationship information was obtained at the atomic and membrane level. Our findings will facilitate the discovery of novel polymyxins against MDR Gram-negative pathogens.
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Affiliation(s)
- Xukai Jiang
- Biomedicine Discovery Institute, Infection & Immunity Program and Department of Microbiology, Monash University, Melbourne, Australia
| | - Kai Yang
- Centre for Soft Condensed Matter Physics and Interdisciplinary Research & School of Physical Science and Technology, Soochow University, Suzhou, China
| | - Bing Yuan
- Centre for Soft Condensed Matter Physics and Interdisciplinary Research & School of Physical Science and Technology, Soochow University, Suzhou, China
| | - Meiling Han
- Biomedicine Discovery Institute, Infection & Immunity Program and Department of Microbiology, Monash University, Melbourne, Australia
| | - Yan Zhu
- Biomedicine Discovery Institute, Infection & Immunity Program and Department of Microbiology, Monash University, Melbourne, Australia
| | - Kade D Roberts
- Biomedicine Discovery Institute, Infection & Immunity Program and Department of Microbiology, Monash University, Melbourne, Australia
| | - Nitin A Patil
- Biomedicine Discovery Institute, Infection & Immunity Program and Department of Microbiology, Monash University, Melbourne, Australia
| | - Jingliang Li
- Institute for Frontier Materials, Deakin University, Geelong, Victoria, Australia
| | - Bin Gong
- School of Computer Science and Technology, Shandong University, Jinan, China
| | - Robert E W Hancock
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Tony Velkov
- Department of Pharmacology & Therapeutics, University of Melbourne, Melbourne, Australia
| | - Falk Schreiber
- Department of Computer and Information Science, University of Konstanz, Konstanz, Germany
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jian Li
- Biomedicine Discovery Institute, Infection & Immunity Program and Department of Microbiology, Monash University, Melbourne, Australia
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28
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Srinivasan R, Santhakumari S, Poonguzhali P, Geetha M, Dyavaiah M, Xiangmin L. Bacterial Biofilm Inhibition: A Focused Review on Recent Therapeutic Strategies for Combating the Biofilm Mediated Infections. Front Microbiol 2021; 12:676458. [PMID: 34054785 PMCID: PMC8149761 DOI: 10.3389/fmicb.2021.676458] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/14/2021] [Indexed: 12/31/2022] Open
Abstract
Biofilm formation is a major concern in various sectors and cause severe problems to public health, medicine, and industry. Bacterial biofilm formation is a major persistent threat, as it increases morbidity and mortality, thereby imposing heavy economic pressure on the healthcare sector. Bacterial biofilms also strengthen biofouling, affecting shipping functions, and the offshore industries in their natural environment. Besides, they accomplish harsh roles in the corrosion of pipelines in industries. At biofilm state, bacterial pathogens are significantly resistant to external attack like antibiotics, chemicals, disinfectants, etc. Within a cell, they are insensitive to drugs and host immune responses. The development of intact biofilms is very critical for the spreading and persistence of bacterial infections in the host. Further, bacteria form biofilms on every probable substratum, and their infections have been found in plants, livestock, and humans. The advent of novel strategies for treating and preventing biofilm formation has gained a great deal of attention. To prevent the development of resistant mutants, a feasible technique that may target adhesive properties without affecting the bacterial vitality is needed. This stimulated research is a rapidly growing field for applicable control measures to prevent biofilm formation. Therefore, this review discusses the current understanding of antibiotic resistance mechanisms in bacterial biofilm and intensely emphasized the novel therapeutic strategies for combating biofilm mediated infections. The forthcoming experimental studies will focus on these recent therapeutic strategies that may lead to the development of effective biofilm inhibitors than conventional treatments.
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Affiliation(s)
- Ramanathan Srinivasan
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, School of Life Sciences, Fujian Agriculture and Forestry University, Fujian, China.,Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fujian, China
| | - Sivasubramanian Santhakumari
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry, India
| | | | - Mani Geetha
- PG Research and Department of Microbiology, St. Joseph's College of Arts and Science (Autonomous), Tamil Nadu, India
| | - Madhu Dyavaiah
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Lin Xiangmin
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, School of Life Sciences, Fujian Agriculture and Forestry University, Fujian, China.,Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fujian, China.,Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fujian, China
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29
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Lin L, Du Y, Song J, Wang W, Yang C. Imaging Commensal Microbiota and Pathogenic Bacteria in the Gut. Acc Chem Res 2021; 54:2076-2087. [PMID: 33856204 DOI: 10.1021/acs.accounts.1c00068] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As a newly discovered organ, gut microbiota has been extensively studied in the last two decades, with their highly diverse and fundamental roles in the physiology of many organs and systems of the host being gradually revealed. However, most of the current research heavily relies on DNA sequencing-based methodologies. To truly understand the complex physiological and pathological functions demonstrated by commensal and pathogenic gut bacteria, we need more powerful methods and tools, among which imaging strategies suitable for approaching this ecosystem in different settings are one of the most desirable. Although the phrase gut "dark matter" is often used in referring to the unculturability of many gut bacteria, it is also applicable to describing the formidable difficulties in visualizing these microbes in the intestines. To develop suitable and versatile chemical and biological tools for imaging bacteria in the gut, great efforts have been devoted in the past several years.In this Account, we highlight the recent progress made by our group and other laboratories in the development of visualization strategies for commensal microbiota and pathogenic bacteria in the gut. First, we summarize our efforts toward the development of derivatized antibiotic staining probes that directly bind to specific bacterial surface structures for selective labeling of different groups of gut bacteria. Next, metabolic labeling-based imaging strategies, using unnatural amino acids, unnatural sugars, and stable isotopes, for imaging gut bacteria on various scales and in different settings are discussed in detail. We then introduce nucleic acid staining-based bacterial imaging, using either general nucleic acid-binding reagents or selective-labeling techniques (e.g., fluorescence in situ hybridization) to meet the diverse needs in gut microbiota research. This classical imaging strategy has witnessed a renaissance owing to a series of new technical advancements. Furthermore, despite the notorious difficulties of performing genetic manipulations in many commensal gut bacteria, great effort has been made recently in engineering gut bacteria with reporters like fluorescent proteins and acoustic response proteins.Our perspectives on the current limitations of the chemical tools and strategies and the future directions for improvement are also presented. We hope that this Account can offer valuable references to spark new ideas and invite new efforts to help decipher the complex biological and chemical interactions between commensal microbiota and pathogenic bacteria and the hosts.
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Affiliation(s)
- Liyuan Lin
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Yahui Du
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Jia Song
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Wei Wang
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Chaoyong Yang
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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30
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Zhu J, Hu C, Zeng Z, Deng X, Zeng L, Xie S, Fang Y, Jin Y, Alezra V, Wan Y. Polymyxin B-inspired non-hemolytic tyrocidine A analogues with significantly enhanced activity against gram-negative bacteria: How cationicity impacts cell specificity and antibacterial mechanism. Eur J Med Chem 2021; 221:113488. [PMID: 33991963 DOI: 10.1016/j.ejmech.2021.113488] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 03/31/2021] [Accepted: 04/18/2021] [Indexed: 11/25/2022]
Abstract
Naturally occurring cyclic antimicrobial peptides (AMPs) such as tyrocidine A (Tyrc A) and gramicidin S (GS) are appealing targets for the development of novel antibiotics. However, their therapeutic potentials are limited by undesired hemolytic activity and relatively poor activity against Gram-negative bacteria. Inspired by polycationic lipopeptide polymyxin B (PMB), the so called 'last-resort' antibiotic for the treatment of infections caused by multidrug-resistant Gram-negative bacteria, we synthesized and biologically evaluated a series of polycationic analogues derived from Tyrc A. We were able to obtain peptide 8 that possesses 5 positive charges exhibiting potent activities against both Gram-negative and Gram-positive bacteria along with totally diminished hemolytic activity. Intriguingly, antibacterial mechanism studies revealed that, rather than the 'pore forming' model that possessed by Tyrc A, peptide 8 likely diffuses membrane in a 'detergent-like' manner. Furthermore, when treating mice with peritonitis-sepsis, peptide 8 showed excellent antibacterial and anti-inflammatory activities in vivo.
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Affiliation(s)
- Jibao Zhu
- National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China
| | - Chengfei Hu
- National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China
| | - Zizhen Zeng
- National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China
| | - Xiaoyu Deng
- Minist Educ, Key Lab Modern Preparat TCM, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China
| | - Lingbing Zeng
- Department of Clinical Laboratory, The First Affiliated Hospital of Nanchang University, 17 Yongwaizheng Street, Donghu, Nanchang, 330006, PR China
| | - Saisai Xie
- National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China
| | - Yuanying Fang
- National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China
| | - Yi Jin
- National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China
| | - Valérie Alezra
- Laboratoire de Méthodologie, Synthèse et Molécules Thérapeutiques (ICMMO), UMR 8182, CNRS, Université Paris-Saclay, Bât 410, Facultédes Sciences D'Orsay, Orsay, 291405, France
| | - Yang Wan
- National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, PR China; Laboratoire de Méthodologie, Synthèse et Molécules Thérapeutiques (ICMMO), UMR 8182, CNRS, Université Paris-Saclay, Bât 410, Facultédes Sciences D'Orsay, Orsay, 291405, France; State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University, 15 Yuchai Road, Guilin, 541004, PR China.
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31
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Abstract
Although antimicrobial resistance is an increasingly significant public health concern, there have only been two new classes of antibiotics approved for human use since the 1960s. Understanding the mechanisms of action of antibiotics is critical for novel antibiotic discovery, but novel approaches are needed that do not exclusively rely on experiments. Molecular dynamics simulation is a computational tool that uses simple models of the atoms in a system to discover nanoscale insights into the dynamic relationship between mechanism and biological function. Such insights can lay the framework for elucidating the mechanism of action and optimizing antibiotic templates. Antimicrobial peptides represent a promising solution to escalating antimicrobial resistance, given their lesser tendency to induce resistance than that of small-molecule antibiotics. Simulations of these agents have already revealed how they interact with bacterial membranes and the underlying physiochemical features directing their structure and function. In this minireview, we discuss how traditional molecular dynamics simulation works and its role and potential for the development of new antibiotic candidates with an emphasis on antimicrobial peptides.
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32
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Maiden MM, Waters CM. Triclosan depletes the membrane potential in Pseudomonas aeruginosa biofilms inhibiting aminoglycoside induced adaptive resistance. PLoS Pathog 2020; 16:e1008529. [PMID: 33125434 PMCID: PMC7657502 DOI: 10.1371/journal.ppat.1008529] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 11/11/2020] [Accepted: 09/15/2020] [Indexed: 12/18/2022] Open
Abstract
Biofilm-based infections are difficult to treat due to their inherent resistance to antibiotic treatment. Discovering new approaches to enhance antibiotic efficacy in biofilms would be highly significant in treating many chronic infections. Exposure to aminoglycosides induces adaptive resistance in Pseudomonas aeruginosa biofilms. Adaptive resistance is primarily the result of active antibiotic export by RND-type efflux pumps, which use the proton motive force as an energy source. We show that the protonophore uncoupler triclosan depletes the membrane potential of biofilm growing P. aeruginosa, leading to decreased activity of RND-type efflux pumps. This disruption results in increased intracellular accumulation of tobramycin and enhanced antimicrobial activity in vitro. In addition, we show that triclosan enhances tobramycin effectiveness in vivo using a mouse wound model. Combining triclosan with tobramycin is a new anti-biofilm strategy that targets bacterial energetics, increasing the susceptibility of P. aeruginosa biofilms to aminoglycosides.
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Affiliation(s)
- Michael M. Maiden
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
- The BEACON Center for The Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Christopher M. Waters
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
- The BEACON Center for The Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
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33
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Espeche JC, Martínez M, Maturana P, Cutró A, Semorile L, Maffia PC, Hollmann A. Unravelling the mechanism of action of “de novo” designed peptide P1 with model membranes and gram-positive and gram-negative bacteria. Arch Biochem Biophys 2020; 693:108549. [DOI: 10.1016/j.abb.2020.108549] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 12/14/2022]
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34
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Tsakou F, Jersie-Christensen R, Jenssen H, Mojsoska B. The Role of Proteomics in Bacterial Response to Antibiotics. Pharmaceuticals (Basel) 2020; 13:E214. [PMID: 32867221 PMCID: PMC7559545 DOI: 10.3390/ph13090214] [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: 07/17/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 02/07/2023] Open
Abstract
For many years, we have tried to use antibiotics to eliminate the persistence of pathogenic bacteria. However, these infectious agents can recover from antibiotic challenges through various mechanisms, including drug resistance and antibiotic tolerance, and continue to pose a global threat to human health. To design more efficient treatments against bacterial infections, detailed knowledge about the bacterial response to the commonly used antibiotics is required. Proteomics is a well-suited and powerful tool to study molecular response to antimicrobial compounds. Bacterial response profiling from system-level investigations could increase our understanding of bacterial adaptation, the mechanisms behind antibiotic resistance and tolerance development. In this review, we aim to provide an overview of bacterial response to the most common antibiotics with a focus on the identification of dynamic proteome responses, and through published studies, to elucidate the formation mechanism of resistant and tolerant bacterial phenotypes.
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Affiliation(s)
| | | | | | - Biljana Mojsoska
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark; (F.T.); (R.J.-C.); (H.J.)
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35
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Xu C, Chen K, Chan KF, Chan EWC, Guo X, Chow HY, Zhao G, Zeng P, Wang M, Zhu Y, Li X, Wong K, Chen S. Imidazole Type Antifungal Drugs Are Effective Colistin Adjuvants That Resensitize Colistin‐Resistant
Enterobacteriaceae. ADVANCED THERAPEUTICS 2020. [DOI: 10.1002/adtp.202000084] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Chen Xu
- State Key Lab of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
- Department of Infectious Diseases and Public Health Jockey Club College of Veterinary Medicine and Life Sciences City University of Hong Kong Kowloon 999077 Hong Kong
| | - Kaichao Chen
- Department of Infectious Diseases and Public Health Jockey Club College of Veterinary Medicine and Life Sciences City University of Hong Kong Kowloon 999077 Hong Kong
| | - Kin Fai Chan
- State Key Lab of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
| | - Edward Wai Chi Chan
- State Key Lab of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
| | - Xuyun Guo
- Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
| | - Hoi Yee Chow
- Department of Chemistry The University of Hong Kong Pokfulam Hong Kong
| | - Guangming Zhao
- Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
| | - Ping Zeng
- State Key Lab of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
| | - Miaomiao Wang
- State Key Lab of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
- Department of Infectious Diseases and Public Health Jockey Club College of Veterinary Medicine and Life Sciences City University of Hong Kong Kowloon 999077 Hong Kong
| | - Ye Zhu
- Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
| | - Xuechen Li
- Department of Chemistry The University of Hong Kong Pokfulam Hong Kong
| | - Kwok‐Yin Wong
- State Key Lab of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
| | - Sheng Chen
- Department of Infectious Diseases and Public Health Jockey Club College of Veterinary Medicine and Life Sciences City University of Hong Kong Kowloon 999077 Hong Kong
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Antibiotic Resistance by Enzymatic Modification of Antibiotic Targets. Trends Mol Med 2020; 26:768-782. [PMID: 32493628 DOI: 10.1016/j.molmed.2020.05.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 11/21/2022]
Abstract
Antibiotic resistance remains a significant threat to modern medicine. Modification of the antibiotic target is a resistance strategy that is increasingly prevalent among pathogens. Examples include resistance to glycopeptide and polymyxin antibiotics that occurs via chemical modification of their molecular targets in the cell envelope. Similarly, many ribosome-targeting antibiotics are impaired by methylation of the rRNA. In these cases, the antibiotic target is subjected to enzymatic modification rather than genetic mutation, and in many instances the resistance enzymes are readily mobilized among pathogens. Understanding the enzymes responsible for these modifications is crucial to combat resistance. Here, we review our current understanding of enzymatic modification of antibiotic targets as well as discuss efforts to combat these resistance mechanisms.
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Adaptive and Mutational Responses to Peptide Dendrimer Antimicrobials in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2020; 64:AAC.02040-19. [PMID: 32015046 PMCID: PMC7179292 DOI: 10.1128/aac.02040-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/24/2020] [Indexed: 01/15/2023] Open
Abstract
Colistin (polymyxin E) is a last-resort antibiotic against multidrug-resistant isolates of Pseudomonas aeruginosa. However, the nephro-toxicity of colistin limits its use, spurring the interest in novel antimicrobial peptides (AMP). Here, we show that the synthetic AMP-dendrimer G3KL (MW 4,531.38 Da, 15 positive charges, MIC = 8 mg/liter) showed faster killing than polymyxin B (Pmx-B) with no detectable resistance selection in P. aeruginosa strain PA14. Colistin (polymyxin E) is a last-resort antibiotic against multidrug-resistant isolates of Pseudomonas aeruginosa. However, the nephro-toxicity of colistin limits its use, spurring the interest in novel antimicrobial peptides (AMP). Here, we show that the synthetic AMP-dendrimer G3KL (MW 4,531.38 Da, 15 positive charges, MIC = 8 mg/liter) showed faster killing than polymyxin B (Pmx-B) with no detectable resistance selection in P. aeruginosa strain PA14. Spontaneous mutants selected on Pmx-B, harboring loss of function mutations in the PhoQ sensor kinase gene, showed increased Pmx-B MICs and arnB operon expression (4-amino-l-arabinose addition to lipid A), but remained susceptible to dendrimers. Two mutants carrying a missense mutation in the periplasmic loop of the PmrB sensor kinase showed increased MICs for Pmx-B (8-fold) and G3KL (4-fold) but not for the dendrimer T7 (MW 4,885.64 Da, 16 positive charges, MIC = 8 mg/liter). The pmrB mutants showed increased expression of the arnB operon as well as of the speD2-speE2-PA4775 operon, located upstream of pmrAB, and involved in polyamine biosynthesis. Exogenous supplementation with the polyamines spermine and norspermine increased G3KL and T7 MICs in a phoQ mutant background but not in the PA14 wild type. This suggests that both addition of 4-amino-l-arabinose and secretion of polyamines are required to reduce susceptibility to dendrimers, probably neutralizing the negative charges present on the lipid A and the 2-keto-3-deoxyoctulosonic acid (KDO) sugars of the lipopolysaccharide (LPS), respectively. We further show by transcriptome analysis that the dendrimers G3KL and T7 induce adaptive responses through the CprRS two-component system in PA14.
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Norouz Dizaji A, Ding D, Kutsal T, Turk M, Kong D, Piskin E. In vivo imaging/detection of MRSA bacterial infections in mice using fluorescence labelled polymeric nanoparticles carrying vancomycin as the targeting agent. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2019; 31:293-309. [PMID: 31762403 DOI: 10.1080/09205063.2019.1692631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This study aims to develop fluorescence labelled polymeric nanoparticle (NP) carrying vancomycin as the targeting agent for in vivo imaging of Methicillin-resistant Staphylococcus aureus bacterial infections in animal models. Maleimide functionalized 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide (polyethylene glycol)-2000] as the main was carrier matrix to prepare the NPs. A fluorescence probe, namely, poly[9,9'-bis (6″-N,N,N-trimethylammonium) hexyl) fluorene-co-alt-4,7-(2,1,3-benzothiadiazole) dibromide] was encapsulated within these NPs by ultrasonication successfully. UV-Vis spectro- photometry of the NPs showed the characteristic shifting on the peak of conjugated polymers indicating successful packaging of this compound with lipid bilayers in nanoscales. Zeta-sizer and TEM analysis showed that the prepared NPs have a diameter of 80-100 nm in a narrow size distribution. Thiolated vancomycin was synthesized and attached to the NPs as the targeting agent. FTIR and MALDI-TOF spectroscopy analysis confirmed the immobilization. The specific targeting properties of the vancomycin conjugated NPs to the target bacteria were first confirmed in in vitro bacterial cultures in which Escherichia coli was the non-target bacteria - using confocal microscopy and TEM. Imaging of bacterial infections in vivo was investigated in mice model using a non-invasive live animal fluorescence imaging technique. The results confirmed that bacterial infections can be detected using these novel polymeric NPs carrying fluorescence probes for imaging and vancomycin as the targeting agent - in vivo successfully.
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Affiliation(s)
- Araz Norouz Dizaji
- Bioengineering Division, Institute of Graduate Studies, Hacettepe University, Beytepe, Ankara, Turkey
| | - Dan Ding
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials, Ministry of Education, and College of Life Sciences, Nankai University, Tianjin, China
| | - Tulin Kutsal
- Faculty of Engineering, Chemical Engineering Department, Hacettepe University, Beytepe, Ankara, Turkey
| | - Mustafa Turk
- Faculty of Engineering, Department of Bioengineering, Kirikkale University, Yahsihan, Kirikkale, Turkey
| | - Deling Kong
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials, Ministry of Education, and College of Life Sciences, Nankai University, Tianjin, China
| | - Erhan Piskin
- Bioengineering Division, Institute of Graduate Studies, Hacettepe University, Beytepe, Ankara, Turkey.,NanoBMT: Nanobiyomedtek Biyomedikal ve Biyoteknoloji San.Tic.Ltd.Şti, Bilkent, Ankara, Turkey
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Outer Membrane Interaction Kinetics of New Polymyxin B Analogs in Gram-Negative Bacilli. Antimicrob Agents Chemother 2019; 63:AAC.00935-19. [PMID: 31332075 DOI: 10.1128/aac.00935-19] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/18/2019] [Indexed: 11/20/2022] Open
Abstract
Infections caused by drug-resistant Gram-negative bacilli are a severe global health threat, limiting effective drug choices for treatment. In this study, polymyxin analogs designed to have reduced nephrotoxicity, direct activity, and potentiating activity were assessed for inhibition and outer membrane interaction kinetics against wild-type (WT) and polymyxin or multidrug-resistant (MDR) Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae In MIC assays, two polymyxin B (PMB) analogs (SPR1205 and SPR206) and a polymyxin E analog (SPR946), with shortened peptide side chains and branched aminobutyryl N termini, exhibited promising activity compared with PMB and previously tested control polymyxin analogs SPR741 and polymyxin B nonapeptide (PMBN). Using dansyl-polymyxin (DPX) binding to assess the affinity of interaction with lipopolysaccharide (LPS), purified or in the context of intact cells, SPR206 exhibited similar affinities to PMB but higher affinities than the other SPR analogs. Outer membrane permeabilization measured by the 1-N-phenyl-napthylamine (NPN) assay did not differ significantly between the polymyxin analogs. Moreover, Hill numbers were greater than 1 for most of the compounds tested on E. coli and P. aeruginosa strains which indicates that the disruption of the outer membrane by one molecule of compound cooperatively enhances the subsequent interactions of other molecules against WT and MDR strains. The high activity demonstrated by SPR206 as well as its ability to displace LPS and permeabilize the outer membrane of multiple strains of Gram-negative bacilli while showing cooperative potential with other membrane disrupting compounds supports further research with this polymyxin analog.
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Dwivedi R, Aggarwal P, Bhavesh NS, Kaur KJ. Design of therapeutically improved analogue of the antimicrobial peptide, indolicidin, using a glycosylation strategy. Amino Acids 2019; 51:1443-1460. [PMID: 31485742 DOI: 10.1007/s00726-019-02779-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/27/2019] [Indexed: 02/01/2023]
Abstract
Indolicidin is a member of cathelicidin family which displays broad spectrum antimicrobial activity. Severe toxicity and aggregation propensity associated with indolicidin pose a huge limitation to its probable therapeutic application. We are reporting the use of glycosylation strategy to design an analogue of indolicidin and subsequently explore structural and functional effects of sugar on it. Our study led to the design of a potent antibacterial glycosylated peptide, [βGlc-T9,K7]indolicidin, which showed decreased toxicity against erythrocytes and macrophage cells and thus a higher therapeutic selectivity. The incorporation of sugar also increased the solubility of the peptide. The mode of bacterial killing, functional stability, LPS binding, and cytokine inhibitory potential of the peptide, however, seemed unaffected upon glycosylation. Absence of significant changes in structure upon glycosylation accounts for the possibly retained functions and mode of action of the peptide. Our report thus presents the designing of an indolicidin analogue with improved therapeutic potential by substituting aromatic amino acid with glycosylated amino acid as a promising strategy for the first time.
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Affiliation(s)
- Rohini Dwivedi
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Priyanka Aggarwal
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Neel S Bhavesh
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Kanwal J Kaur
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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Coagulation factors VII, IX and X are effective antibacterial proteins against drug-resistant Gram-negative bacteria. Cell Res 2019; 29:711-724. [PMID: 31399697 PMCID: PMC6796875 DOI: 10.1038/s41422-019-0202-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 06/24/2019] [Indexed: 02/05/2023] Open
Abstract
Infections caused by drug-resistant “superbugs” pose an urgent public health threat due to the lack of effective drugs; however, certain mammalian proteins with intrinsic antibacterial activity might be underappreciated. Here, we reveal an antibacterial property against Gram-negative bacteria for factors VII, IX and X, three proteins with well-established roles in initiation of the coagulation cascade. These factors exert antibacterial function via their light chains (LCs). Unlike many antibacterial agents that target cell metabolism or the cytoplasmic membrane, the LCs act by hydrolyzing the major components of bacterial outer membrane, lipopolysaccharides, which are crucial for the survival of Gram-negative bacteria. The LC of factor VII exhibits in vitro efficacy towards all Gram-negative bacteria tested, including extensively drug-resistant (XDR) pathogens, at nanomolar concentrations. It is also highly effective in combating XDR Pseudomonas aeruginosa and Acinetobacter baumannii infections in vivo. Through decoding a unique mechanism whereby factors VII, IX and X behave as antimicrobial proteins, this study advances our understanding of the coagulation system in host defense, and suggests that these factors may participate in the pathogenesis of coagulation disorder-related diseases such as sepsis via their dual functions in blood coagulation and resistance to infection. Furthermore, this study may offer new strategies for combating Gram-negative “superbugs”.
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Poole K, Gilmour C, Farha MA, Parkins MD, Klinoski R, Brown ED. Meropenem potentiation of aminoglycoside activity against Pseudomonas aeruginosa: involvement of the MexXY-OprM multidrug efflux system. J Antimicrob Chemother 2019; 73:1247-1255. [PMID: 29420743 DOI: 10.1093/jac/dkx539] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/20/2017] [Indexed: 12/25/2022] Open
Abstract
Objectives To assess the ability of meropenem to potentiate aminoglycoside (AG) activity against laboratory and AG-resistant cystic fibrosis (CF) isolates of Pseudomonas aeruginosa and to elucidate its mechanism of action. Methods AG resistance gene deletions were engineered into P. aeruginosa laboratory and CF isolates using standard gene replacement technology. Susceptibility to AGs ± meropenem (at ½ MIC) was assessed using a serial 2-fold dilution assay. mexXY expression and MexXY-OprM efflux activity were quantified using quantitative PCR and an ethidium bromide accumulation assay, respectively. Results A screen for agents that rendered WT P. aeruginosa susceptible to a sub-MIC concentration of the AG paromomycin identified the carbapenem meropenem, which potentiated several additional AGs. Meropenem potentiation of AG activity was largely lost in a mutant lacking the MexXY-OprM multidrug efflux system, an indication that it was targeting this efflux system in enhancing P. aeruginosa susceptibility to AGs. Meropenem failed to block AG induction of mexXY expression or MexXY-OprM efflux activity, suggesting that it may be interfering with some MexXY-dependent process linked to AG susceptibility. Meropenem potentiated AG activity versus AG-resistant CF isolates, enhancing susceptibility to at least one AG in all isolates and susceptibility to all tested AGs in 50% of the isolates. Notably, meropenem potentiation of AG activity was linked to MexXY in some but not all CF isolates in which this was examined. Conclusions Meropenem potentiates AG activity against laboratory and CF strains of P. aeruginosa, both dependent on and independent of MexXY, highlighting the complexity of AG resistance in this organism.
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Affiliation(s)
- Keith Poole
- Department of Biomedical and Molecular Sciences, Botterell Hall, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Christie Gilmour
- Department of Biomedical and Molecular Sciences, Botterell Hall, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Maya A Farha
- M.G. DeGroote Institute for Infectious Disease Research and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Michael D Parkins
- Department of Microbiology Immunology and Infectious Diseases and Department of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Rachael Klinoski
- Department of Biomedical and Molecular Sciences, Botterell Hall, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Eric D Brown
- M.G. DeGroote Institute for Infectious Disease Research and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
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Yadav K, Kumar S, Mishra D, Asad M, Mitra M, Yavvari PS, Gupta S, Vedantham M, Ranga P, Komalla V, Pal S, Sharma P, Kapil A, Singh A, Singh N, Srivastava A, Thukral L, Bajaj A. Deciphering the Role of Intramolecular Networking in Cholic Acid–Peptide Conjugates on the Lipopolysaccharide Surface in Combating Gram-Negative Bacterial Infections. J Med Chem 2019; 62:1875-1886. [DOI: 10.1021/acs.jmedchem.8b01357] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Kavita Yadav
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
- Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Sandeep Kumar
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
- Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Deepakkumar Mishra
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Mohammad Asad
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Madhurima Mitra
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Prabhu S. Yavvari
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal 462030, Madhya Pradesh, India
| | - Siddhi Gupta
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Madhukar Vedantham
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Pavit Ranga
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Varsha Komalla
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Sanjay Pal
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
- Kalinga Institute of Industrial Technology, Bhubaneswar 751024, Odisha, India
| | - Priyanka Sharma
- Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Arti Kapil
- Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Archana Singh
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
| | - Nirpendra Singh
- Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Aasheesh Srivastava
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal 462030, Madhya Pradesh, India
| | - Lipi Thukral
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
| | - Avinash Bajaj
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, 3rd Milestone Faridabad-Gurgaon Expressway, NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
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Khadka N, Aryal CM, Pan J. Lipopolysaccharide-Dependent Membrane Permeation and Lipid Clustering Caused by Cyclic Lipopeptide Colistin. ACS OMEGA 2018; 3:17828-17834. [PMID: 30613815 PMCID: PMC6312645 DOI: 10.1021/acsomega.8b02260] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 12/06/2018] [Indexed: 05/16/2023]
Abstract
Polyanionic lipopolysaccharides (LPS) play an important role in regulating the permeability of the outer membrane (OM) of Gram-negative bacteria. Impairment of the LPS-enriched OM is essential in initiating the bactericidal activity of polymyxins. We are interested in how colistin (polymyxin E) affects the membrane permeability of LPS/phospholipid bilayers. Our vesicle leakage experiment showed that colistin binding enhanced bilayer permeability; the maximum increase in the bilayer permeability was positively correlated with the LPS fraction. Addition of magnesium ions abolished the effect of LPS in enhancing bilayer permeabilization. To describe the vesicle leakage behavior from a structural perspective, we performed liquid atomic force microscopy (AFM) measurements on planar lipid bilayers. We found that colistin caused the formation of nano- and macroclusters that protruded from the bilayer by ∼2 nm. Moreover, cluster development was promoted by increasing the fraction of LPS or colistin concentration but inhibited by magnesium ions. To explain our experimental data, we proposed a lipid clustering model where colistin binds to LPS to form large-scale complexes segregated from zwitterionic phospholipids. The discontinuity (and thickness mismatch) at the edge of LPS-colistin clusters will create a passage that allows solutes to permeate through. The proposed model is consistent with all data obtained from our leakage and AFM experiments. Our results of LPS-dependent membrane restructuring provided useful insights into the mechanism that could be used by polymyxins in impairing the permeability barrier of the OM of Gram-negative bacteria.
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Feigman MS, Kim S, Pidgeon SE, Yu Y, Ongwae GM, Patel DS, Regen S, Im W, Pires MM. Synthetic Immunotherapeutics against Gram-negative Pathogens. Cell Chem Biol 2018; 25:1185-1194.e5. [PMID: 29983273 PMCID: PMC6195440 DOI: 10.1016/j.chembiol.2018.05.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/06/2018] [Accepted: 05/29/2018] [Indexed: 12/11/2022]
Abstract
While traditional drug discovery continues to be an important platform for the search of new antibiotics, alternative approaches should also be pursued to complement these efforts. We herein designed a class of molecules that decorate bacterial cell surfaces with the goal of re-engaging components of the immune system toward Escherichia coli and Pseudomonas aeruginosa. More specifically, conjugates were assembled using polymyxin B (an antibiotic that inherently attaches to the surface of Gram-negative pathogens) and antigenic epitopes that recruit antibodies found in human serum. We established that the spacer length played a significant role in hapten display within the bacterial cell surface, a result that was confirmed both experimentally and via molecular dynamics simulations. Most importantly, we demonstrated the specific killing of bacteria by our agent in the presence of human serum. By enlisting the immune system, these agents have the potential to pave the way for a potent antimicrobial modality.
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Affiliation(s)
| | - Seonghoon Kim
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Sean E Pidgeon
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
| | - Yuming Yu
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
| | | | - Dhilon S Patel
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Steven Regen
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
| | - Wonpil Im
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Marcos M Pires
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA.
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Johnson TR, Gómez BI, McIntyre MK, Dubick MA, Christy RJ, Nicholson SE, Burmeister DM. The Cutaneous Microbiome and Wounds: New Molecular Targets to Promote Wound Healing. Int J Mol Sci 2018; 19:ijms19092699. [PMID: 30208569 PMCID: PMC6164292 DOI: 10.3390/ijms19092699] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 12/16/2022] Open
Abstract
The ecological community of microorganisms in/on humans, termed the microbiome, is vital for sustaining homeostasis. While culture-independent techniques have revealed the role of the gut microbiome in human health and disease, the role of the cutaneous microbiome in wound healing is less defined. Skin commensals are essential in the maintenance of the epithelial barrier function, regulation of the host immune system, and protection from invading pathogenic microorganisms. In this review, we summarize the literature derived from pre-clinical and clinical studies on how changes in the microbiome of various acute and chronic skin wounds impact wound healing tissue regeneration. Furthermore, we review the mechanistic insights garnered from model wound healing systems. Finally, in the face of growing concern about antibiotic-resistance, we will discuss alternative strategies for the treatment of infected wounds to improve wound healing and outcomes. Taken together, it has become apparent that commensals, symbionts, and pathogens on human skin have an intimate role in the inflammatory response that highlights several potential strategies to treat infected, non-healing wounds. Despite these promising results, there are some contradictory and controversial findings from existing studies and more research is needed to define the role of the human skin microbiome in acute and chronic wound healing.
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Affiliation(s)
- Taylor R Johnson
- Department of Surgery, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
| | - Belinda I Gómez
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
| | - Matthew K McIntyre
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
- School of Medicine, New York Medical College, Valhalla, New York, NY 10595, USA.
| | - Michael A Dubick
- Department of Surgery, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
| | - Robert J Christy
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
| | - Susannah E Nicholson
- Department of Surgery, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
| | - David M Burmeister
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
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Wang W, Chen X. Antibiotics-based fluorescent probes for selective labeling of Gram-negative and Gram-positive bacteria in living microbiotas. Sci China Chem 2018. [DOI: 10.1007/s11426-018-9236-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Aminoglycoside Concentrations Required for Synergy with Carbapenems against Pseudomonas aeruginosa Determined via Mechanistic Studies and Modeling. Antimicrob Agents Chemother 2017; 61:AAC.00722-17. [PMID: 28893782 DOI: 10.1128/aac.00722-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 09/04/2017] [Indexed: 01/24/2023] Open
Abstract
This study aimed to systematically identify the aminoglycoside concentrations required for synergy with a carbapenem and characterize the permeabilizing effect of aminoglycosides on the outer membrane of Pseudomonas aeruginosa Monotherapies and combinations of four aminoglycosides and three carbapenems were studied for activity against P. aeruginosa strain AH298-GFP in 48-h static-concentration time-kill studies (SCTK) (inoculum: 107.6 CFU/ml). The outer membrane-permeabilizing effect of tobramycin alone and in combination with imipenem was characterized via electron microscopy, confocal imaging, and the nitrocefin assay. A mechanism-based model (MBM) was developed to simultaneously describe the time course of bacterial killing and prevention of regrowth by imipenem combined with each of the four aminoglycosides. Notably, 0.25 mg/liter of tobramycin, which was inactive in monotherapy, achieved synergy (i.e., ≥2-log10 more killing than the most active monotherapy at 24 h) combined with imipenem. Electron micrographs, confocal image analyses, and the nitrocefin uptake data showed distinct outer membrane damage by tobramycin, which was more extensive for the combination with imipenem. The MBM indicated that aminoglycosides enhanced the imipenem target site concentration up to 4.27-fold. Tobramycin was the most potent aminoglycoside to permeabilize the outer membrane; tobramycin (0.216 mg/liter), gentamicin (0.739 mg/liter), amikacin (1.70 mg/liter), or streptomycin (5.19 mg/liter) was required for half-maximal permeabilization. In summary, our SCTK, mechanistic studies and MBM indicated that tobramycin was highly synergistic and displayed the maximum outer membrane disruption potential among the tested aminoglycosides. These findings support the optimization of highly promising antibiotic combination dosage regimens for critically ill patients.
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Kennedy CA, Fanning S, Karczmarczyk M, Byrne B, Monaghan Á, Bolton D, Sweeney T. Characterizing the Multidrug Resistance of non-O157 Shiga Toxin-ProducingEscherichia coliIsolates from Cattle Farms and Abattoirs. Microb Drug Resist 2017; 23:781-790. [DOI: 10.1089/mdr.2016.0082] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Carrie-Ann Kennedy
- Cell Molecular Biology Laboratory, School of Veterinary Medicine, Veterinary Science Centre, University College Dublin, Dublin, Ireland
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Maria Karczmarczyk
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Brian Byrne
- Teagasc, Ashtown Food Research Centre, Dublin, Ireland
| | - Áine Monaghan
- Teagasc, Ashtown Food Research Centre, Dublin, Ireland
| | - Declan Bolton
- Teagasc, Ashtown Food Research Centre, Dublin, Ireland
| | - Torres Sweeney
- Cell Molecular Biology Laboratory, School of Veterinary Medicine, Veterinary Science Centre, University College Dublin, Dublin, Ireland
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