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Pahlow S, Schmidt S, Pappert T, Thieme L, Makarewicz O, Monecke S, Ehricht R, Weber K, Popp J. Evaluating the potential of vancomycin-modified magnetic beads as a tool for sample preparation in diagnostic assays. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024. [PMID: 39295576 DOI: 10.1039/d4ay01557f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/21/2024]
Abstract
Vancomycin-functionalized micro- or nanoparticles are frequently used for isolation and enrichment of bacteria from various samples. Theoretically, only Gram-positive organisms should adhere to the functionalized surfaces as vancomycin is an antibiotic targeting a peptidoglycan precursor in the cell wall, which in Gram-negative bacteria is shielded by the outer cell membrane. In the literature, however, it is often reported that Gram-negative bacteria also bind efficiently to the vancomycin-modified particles. The goal of our study was to identify the underlying cause for these different findings. For each species several strains, including patient isolates, were investigated, and effects such as day-to-day reproducibility, particle type, and the antimicrobial effect of vancomycin-coupled beads were explored. Overall, we found that there is a strong preference for binding Gram-positive organisms, but the specific yield is heavily influenced by the strain and experimental conditions. For Staphylococcus aureus average yields of approximately 100% were obtained. Respectively, yields of 44% for Staphylococcus cohnii, 22% for Staphylococcus warneri, 17% for Enterococcus faecalis and 5% for vancomycin-sensitive Enterococcus faecium were found. Yields for Gram-negative species (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii) and vancomycin-resistant Enterococcus faecium were below 3%. Our results indicate that the interaction between vancomycin and the D-alanine-D-alanine terminus of the peptidoglycan precursor in the bacterial cell wall is the dominant force responsible for the adherence of the bacteria to the particle surface. It needs to be considered though, that other factors, such as the specific molecules presented on the bacterial surface, as well as the pH, and the ion concentrations in the surrounding medium will also play a role, as these can lead to attractive or repulsive electrostatic forces. Last but not least, when using colony forming unit-based quantification for determining the yields, the influence of cell cluster formation and different sensitivities towards the antimicrobial effect of the vancomycin beads between species and strains needs to be considered.
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Affiliation(s)
- Susanne Pahlow
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
- InfectoGnostics Research Campus Jena, Center for Applied Research, Philosophenweg 7, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology, Member of the Research Alliance "Leibniz Health Technologies", The Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Straße 9, 07745 Jena, Germany.
| | - Sabine Schmidt
- Leibniz Institute of Photonic Technology, Member of the Research Alliance "Leibniz Health Technologies", The Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Straße 9, 07745 Jena, Germany.
| | - Tabea Pappert
- Leibniz Institute of Photonic Technology, Member of the Research Alliance "Leibniz Health Technologies", The Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Straße 9, 07745 Jena, Germany.
| | - Lara Thieme
- Institute of Infectious Diseases and Infection Control, University Hospital Jena - Friedrich Schiller University Jena, Member of the Leibniz Centre for Photonics in Infection Research (LPI), Am Klinikum 1, 07747 Jena, Germany
| | - Oliwia Makarewicz
- Institute of Infectious Diseases and Infection Control, University Hospital Jena - Friedrich Schiller University Jena, Member of the Leibniz Centre for Photonics in Infection Research (LPI), Am Klinikum 1, 07747 Jena, Germany
| | - Stefan Monecke
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
- InfectoGnostics Research Campus Jena, Center for Applied Research, Philosophenweg 7, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology, Member of the Research Alliance "Leibniz Health Technologies", The Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Straße 9, 07745 Jena, Germany.
| | - Ralf Ehricht
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
- InfectoGnostics Research Campus Jena, Center for Applied Research, Philosophenweg 7, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology, Member of the Research Alliance "Leibniz Health Technologies", The Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Straße 9, 07745 Jena, Germany.
| | - Karina Weber
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
- InfectoGnostics Research Campus Jena, Center for Applied Research, Philosophenweg 7, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology, Member of the Research Alliance "Leibniz Health Technologies", The Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Straße 9, 07745 Jena, Germany.
| | - Jürgen Popp
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
- InfectoGnostics Research Campus Jena, Center for Applied Research, Philosophenweg 7, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology, Member of the Research Alliance "Leibniz Health Technologies", The Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Straße 9, 07745 Jena, Germany.
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Qi YK, Tang X, Wei NN, Pang CJ, Du SS, Wang KW. Discovery, synthesis, and optimization of teixobactin, a novel antibiotic without detectable bacterial resistance. J Pept Sci 2022; 28:e3428. [PMID: 35610021 DOI: 10.1002/psc.3428] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 05/07/2022] [Accepted: 05/10/2022] [Indexed: 11/09/2022]
Abstract
Discovering new antibiotics with novel chemical scaffolds and antibacterial mechanisms presents a challenge for medicinal scientists worldwide as the ever-increasing bacterial resistance poses a serious threat to human health. A new cyclic peptide-based antibiotic termed teixobactin was discovered from a screen of uncultured soil bacteria through iChip technology in 2015. Teixobactin exhibits excellent antibacterial activity against all the tested gram-positive pathogens and Mycobacterium tuberculosis, including drug-resistant strains. Given that teixobactin targets the highly conserved lipid II and lipid III, which induces the simultaneous inhibition of both peptidoglycan and teichoic acid synthesis, the emergence of resistance is considered to be rather difficult. The novel structure, potent antibacterial activity, and highly conservative targets make teixobactin a promising lead compound for further antibiotic development. This review provides a comprehensive treatise on the advances of teixobactin in the areas of discovery processes, antibacterial activity, mechanisms of action, chemical synthesis, and structural optimizations. The synthetic methods for the key building block l-allo-End, natural teixobactin, representative teixobactin analogues, as well as the structure-activity relationship studies will be highlighted and discussed in details. Finally, some insights into new trends for the generation of novel teixobactin analogues and tips for future work and directions will be commented.
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Affiliation(s)
- Yun-Kun Qi
- Department of Medicinal Chemistry, School of Pharmacy, Qingdao University, Qingdao, China.,Institute of Innovative Drugs, Qingdao University, Qingdao, China.,State Key Laboratory Base for Eco-Chemical Engineering in College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Xiaowen Tang
- Department of Medicinal Chemistry, School of Pharmacy, Qingdao University, Qingdao, China
| | - Ning-Ning Wei
- Institute of Innovative Drugs, Qingdao University, Qingdao, China
| | - Cheng-Jian Pang
- The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Shan-Shan Du
- State Key Laboratory Base for Eco-Chemical Engineering in College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Ke Wei Wang
- Department of Medicinal Chemistry, School of Pharmacy, Qingdao University, Qingdao, China.,Institute of Innovative Drugs, Qingdao University, Qingdao, China
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Li J, Fernández-Millán P, Boix E. Synergism between Host Defence Peptides and Antibiotics Against Bacterial Infections. Curr Top Med Chem 2020; 20:1238-1263. [DOI: 10.2174/1568026620666200303122626] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 01/22/2020] [Accepted: 02/07/2020] [Indexed: 01/10/2023]
Abstract
Background:Antimicrobial resistance (AMR) to conventional antibiotics is becoming one of the main global health threats and novel alternative strategies are urging. Antimicrobial peptides (AMPs), once forgotten, are coming back into the scene as promising tools to overcome bacterial resistance. Recent findings have attracted attention to the potentiality of AMPs to work as antibiotic adjuvants.Methods:In this review, we have tried to collect the currently available information on the mechanism of action of AMPs in synergy with other antimicrobial agents. In particular, we have focused on the mechanisms of action that mediate the inhibition of the emergence of bacterial resistance by AMPs.Results and Conclusion:We find in the literature many examples where AMPs can significantly reduce the antibiotic effective concentration. Mainly, the peptides work at the bacterial cell wall and thereby facilitate the drug access to its intracellular target. Complementarily, AMPs can also contribute to permeate the exopolysaccharide layer of biofilm communities, or even prevent bacterial adhesion and biofilm growth. Secondly, we find other peptides that can directly block the emergence of bacterial resistance mechanisms or interfere with the community quorum-sensing systems. Interestingly, the effective peptide concentrations for adjuvant activity and inhibition of bacterial resistance are much lower than the required for direct antimicrobial action. Finally, many AMPs expressed by innate immune cells are endowed with immunomodulatory properties and can participate in the host response against infection. Recent studies in animal models confirm that AMPs work as adjuvants at non-toxic concentrations and can be safely administrated for novel combined chemotherapies.
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Affiliation(s)
- Jiarui Li
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Spain
| | - Pablo Fernández-Millán
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Spain
| | - Ester Boix
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Spain
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Katzenmeyer KN, Szott LM, Bryers JD. Artificial opsonin enhances bacterial phagocytosis, oxidative burst and chemokine production by human neutrophils. Pathog Dis 2018; 75:3934653. [PMID: 28859309 DOI: 10.1093/femspd/ftx075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 07/04/2017] [Indexed: 12/23/2022] Open
Abstract
Here, we describe the application of an 'artificial opsonin' to stimulate the innate immune response against Gram-positive bacteria. The artificial opsonin comprises a poly(L-lysine)-graft-poly(ethylene glycol) backbone displaying multiple copies of vancomycin and human IgG-Fc. The vancomycin targets bacteria by recognizing d-Ala-d-Ala-terminated peptides present in the bacterial cell wall. The human IgG-Fc antibody fragments serve as phagocyte recognition moieties that recognize the Fcγ cell surface receptors expressed by professional human phagocytes. Staphylococcus epidermidis RP62A, a biofilm-forming, methicillin-resistant strain, was utilized to investigate the effects of opsonization on phagocytosis, oxidative burst and IL-8 chemokine production by human neutrophils. Results show that opsonization of S. epidermidis RP62A with the artificial opsonin resulted in an ∼2-fold increase in neutrophil phagocytosis. Analysis of the cell supernatant found a 2- to 3-fold increase in neutrophil IL-8 secretion. The neutrophil oxidative burst was investigated using the oxidation-sensitive fluorophore dihydrorhodamine-123. Bacterial opsonization resulted in a 20% increase in fluorescence intensity, indicating a significant increase in the production of reactive oxygen species by the neutrophils. These studies suggest that artificial opsonins may be a novel immunostimulation therapeutic strategy to control infections caused by Gram-positive bacteria, particularly those that are known to be immune evasive and/or antibiotic resistant.
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Affiliation(s)
- Kristy N Katzenmeyer
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Luisa M Szott
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - James D Bryers
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
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Abstract
Emergence of resistance among the most important bacterial pathogens is recognized as a major public health threat affecting humans worldwide. Multidrug-resistant organisms have not only emerged in the hospital environment but are now often identified in community settings, suggesting that reservoirs of antibiotic-resistant bacteria are present outside the hospital. The bacterial response to the antibiotic "attack" is the prime example of bacterial adaptation and the pinnacle of evolution. "Survival of the fittest" is a consequence of an immense genetic plasticity of bacterial pathogens that trigger specific responses that result in mutational adaptations, acquisition of genetic material, or alteration of gene expression producing resistance to virtually all antibiotics currently available in clinical practice. Therefore, understanding the biochemical and genetic basis of resistance is of paramount importance to design strategies to curtail the emergence and spread of resistance and to devise innovative therapeutic approaches against multidrug-resistant organisms. In this chapter, we will describe in detail the major mechanisms of antibiotic resistance encountered in clinical practice, providing specific examples in relevant bacterial pathogens.
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Detection of vancomycin resistances in enterococci within 3 ½ hours. Sci Rep 2015; 5:8217. [PMID: 25645753 PMCID: PMC4314646 DOI: 10.1038/srep08217] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/29/2014] [Indexed: 12/26/2022] Open
Abstract
Vancomycin resistant enterococci (VRE) constitute a challenging problem in health care institutions worldwide. Novel methods to rapidly identify resistances are highly required to ensure an early start of tailored therapy and to prevent further spread of the bacteria. Here, a spectroscopy-based rapid test is presented that reveals resistances of enterococci towards vancomycin within 3.5 hours. Without any specific knowledge on the strain, VRE can be recognized with high accuracy in two different enterococci species. By means of dielectrophoresis, bacteria are directly captured from dilute suspensions, making sample preparation very easy. Raman spectroscopic analysis of the trapped bacteria over a time span of two hours in absence and presence of antibiotics reveals characteristic differences in the molecular response of sensitive as well as resistant Enterococcus faecalis and Enterococcus faecium. Furthermore, the spectroscopic fingerprints provide an indication on the mechanisms of induced resistance in VRE.
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Katzenmeyer KN, Bryers JD. Multivalent artificial opsonin for the recognition and phagocytosis of Gram-positive bacteria by human phagocytes. Biomaterials 2011; 32:4042-51. [PMID: 21388677 DOI: 10.1016/j.biomaterials.2011.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 02/04/2011] [Indexed: 12/30/2022]
Abstract
Hospital-acquired infections (HAIs) remain a leading cause of death in the United States. Unfortunately, treatment of HAIs is complicated by the emergence of antibiotic-resistant bacterial strains. In an effort to enhance the body's natural immune response to infection, we have developed an artificial opsonin to promote the recognition, phagocytosis, and destruction of pathogenic bacteria by human phagocytes. The artificial opsonin is constructed from multivalent conjugates of poly(L-lysine)-graft-poly(ethylene glycol) with vancomycin and human IgG-Fc. Our approach utilizes vancomycin's inherent ability to bind to D-Ala-D-Ala terminated peptides present in the cell wall of Gram-positive bacteria. Here, we show that conjugation of vancomycin to PLL-g-PEG prevents its action as an antibiotic and allows vancomycin to function solely as a recognition molecule. Human IgG-Fc antibody fragment serves as a phagocyte recognition molecule and is recognized by the Fcγ cell surface receptors expressed on professional human phagocytes. Using flow cytometry, we found that a polysaccharide-encapsulated, methicillin-resistant strain of Staphylococcus epidermidis is efficiently recognized by the artificial opsonin (nearly 100% of cells were opsonized) and that opsonin binding is specific since it can be inhibited by the soluble cell wall peptide analog acetyl-Lys-D-Ala-D-Ala. Opsonization of S. epidermidis resulted in an approximate 2-fold increase in phagocytosis by a human neutrophil cell line. Notably, Enterococcus faecalis VanB, a bacterial strain with inducible vancomycin resistance, was used to show that the artificial opsonin does not unintentionally induce antibiotic resistance mechanisms.
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Affiliation(s)
- Kristy N Katzenmeyer
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
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