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Mechanism of Microbicidal Action of E-101 Solution, a Myeloperoxidase-Mediated Antimicrobial, and Its Oxidative
Gerald A Denys1, Neil C Devoe2, Polyxeni Gudis2
1Indiana University School of Medicine, Indianapolis, Indiana, USA gdenys@iupui.edu.
Abstract:
E-101 solution is a first-in-class myeloperoxidase-mediated antimicrobial developed for topical application. It is composed of porcine myeloperoxidase (pMPO), glucose oxidase (GO), glucose, sodium chloride, and specific amino acids in an aqueous solution. Once activated, the reactive species hydrogen peroxide (H2O2), hypochlorous acid, and singlet oxygen are generated. We evaluated the treatment effects of E-101 solution and its oxidative products on ultrastructure changes and microbicidal activity against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli Time-kill and transmission electron microscopy studies were also performed using formulations with pMPO or GO omitted. The glutathione membrane protection assay was used to study the neutralization of reactive oxygen species. The potency of E-101 solution was also measured in the presence of serum and whole blood by MIC and minimal bactericidal concentration (MBC) determinations. E-101 solution demonstrated rapid bactericidal activity and ultracellular changes in MRSA and E. coli cells. When pMPO was omitted, high levels of H2O2 generated from GO and glucose demonstrated slow microbicidal activity with minimal cellular damage. When GO was omitted from the formulation, no antimicrobial activity or cellular damage was observed. Protection from exposure to E-101 solution reactive oxygen species in the glutathione protection assay was competitive and temporary. E-101 solution maintained its antimicrobial activity in the presence of inhibitory substances, such as serum and whole blood. E-101 solution is a potent myeloperoxidase enzyme system with multiple oxidative mechanisms of action. Our findings suggest that the primary site where E-101 solution exerts microbicidal action is the cell membrane, by inactivation of essential cell membrane components.
Insights
E-101 solution, a novel antimicrobial, rapidly kills bacteria like MRSA and E. coli by generating reactive oxygen species. Its effectiveness relies on the myeloperoxidase enzyme system, targeting bacterial cell membranes.
Area of Science:
- Biochemistry
- Microbiology
- Antimicrobial Research
Background:
- Topical antimicrobials are crucial for combating resistant bacteria.
- Myeloperoxidase (MPO) enzymes generate reactive species with antimicrobial potential.
- Developing novel agents against multidrug-resistant pathogens like MRSA is a priority.
Purpose of the Study:
- To evaluate the antimicrobial efficacy and mechanism of action of E-101 solution.
- To investigate the role of specific components (porcine MPO and glucose oxidase) in E-101's activity.
- To assess E-101's performance in the presence of biological fluids.
Main Methods:
- Time-kill assays and transmission electron microscopy (TEM) were used to assess microbicidal activity and ultrastructural changes.
- Glutathione protection assay evaluated reactive oxygen species neutralization.
- Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) determined potency in serum and whole blood.
Main Results:
- E-101 solution exhibited rapid bactericidal activity and caused significant ultrastructural damage to MRSA and E. coli.
- Porcine MPO was essential for E-101's potent antimicrobial effect; glucose oxidase alone showed limited activity.
- E-101 maintained antimicrobial potency in serum and whole blood, indicating stability in complex biological environments.
Conclusions:
- E-101 solution is a potent topical antimicrobial agent leveraging myeloperoxidase for broad-spectrum activity.
- The primary mechanism involves cell membrane disruption via multiple oxidative species.
- E-101 demonstrates potential for treating infections caused by resistant bacteria like MRSA.
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