Mechanism of Microbicidal Action of E-101 Solution, a Myeloperoxidase-Mediated Antimicrobial, and its Oxidative Products (original) (raw)
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Journal of Antimicrobial Chemotherapy, 2010
Objectives: E-101 Solution (E-101) is a novel myeloperoxidase-mediated antimicrobial. It is composed of porcine myeloperoxidase (pMPO), glucose oxidase, glucose as the substrate and specific amino acids in an aqueous vehicle. E-101 is being developed for topical application directly into surgical wounds to prevent surgical site infections (SSIs). The in vitro activity of E-101 was investigated. Methods: MIC, MBC, time-kill and antimicrobial combination experiments were performed according to CLSI guidelines with modifications. Resistance selection studies were performed using a serial passage method. Results: E-101 showed MIC 90 values of 0.03, 0.5 and 0.5 mg pMPO/L for staphylococci (n¼ 140), streptococci (n¼ 95) and enterococci (n¼ 55), respectively. MIC 90 values ranged between 0.03-0.5 and ≤0.004-0.12 mg pMPO/L for Enterobacteriaceae (n¼ 148) and Gram-negative non-Enterobacteriaceae (n¼ 92) strains, respectively. There was no antimicrobial tolerance to E-101 for Staphylococcus aureus, Streptococcus agalactiae or Streptococcus pyogenes. Time-kill studies demonstrated a rapid (,30 min) bactericidal effect against S. aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa in a concentrationdependent and time-dependent manner. There was no evidence of stable resistance to E-101 among staphylococci, enterococci, E. coli or P. aeruginosa strains and no evidence of E-101 interaction with antibiotics commonly used in clinical medicine. Conclusions: E-101 shows potent and broad-spectrum in vitro activity against bacteria that are the causative pathogens of SSIs, thereby providing the impetus to test its clinical utility in the prevention of SSIs.
Journal of Antimicrobial Agents, 2021
E-101 solution is a first-in-class myeloperoxidase containing antimicrobial solution developed for topical application. The active ingredients in E-101 solution are two enzymes, porcine myeloperoxidase (pMPO) and glucose oxidase (GO) in an aqueous solution and activated by the addition of a glucose solution. Once activated, the reactive species hydrogen peroxide, hypochlorous acid/hypochlorite (HOCl/OCl-), and singlet oxygen (1 O 2) are generated. We evaluated the effect of whole human blood on the performance of E-101 solution compared to commercially available wound antiseptics and commonly used biocides. The wound cleansers NeutroPhase, Microcyn, and Vashe with the active HOCl/OClcomponent were tested according to the USP-51 effectiveness test in the presence of 0, 1, 2 and 5% blood. Comparative time-kill studies against chlorhexidine, povidone-iodine, sodium oxychlorosene were tested in the presence of 0, 2, 5 10, and 20% blood. In the USP-51 test, E-101 solution demonstrated >2 log10 reduction against bacterial and fungal isolates in the presence of 5% blood at days 14 and 28. With the exception of NeutroPhase activity against S. aureus, all comparable wound antiseptics demonstrated <2 log10 reduction in the presence of 5% blood at days 14 and 28. Time-kill microbicidal data observed in the presence of blood demonstrated that E-101 solution was the most active biocide, followed by chlorhexidine and povidone-iodine. The presence of 2% blood completely inhibited the activity of sodium oxychlorosene. In summary, E-101 solution remained active in the presence of blood containing catalase and other substances that competitively react with 1 O 2 and HOCl/OClas a safe and effective wound antiseptic.
Myeloperoxidase Selectively Binds and Selectively Kills Microbes
Infection and Immunity, 2011
ABSTRACTMyeloperoxidase (MPO) is reported to selectively bind to bacteria. The present study provides direct evidence of MPO binding selectivity and tests the relationship of selective binding to selective killing. The microbicidal effectiveness of H2O2and of OCl−was compared to that of MPO plus H2O2. Synergistic microbicidal action was investigated by combiningStreptococcus sanguinis, a H2O2-producing microbe showing low MPO binding, with high-MPO-bindingEscherichia coli,Staphylococcus aureus, orPseudomonas aeruginosawithout exogenous H2O2, with and without MPO, and with and without erythrocytes (red blood cells [RBCs]). Selectivity of MPO microbicidal action was conventionally measured as the MPO MIC and minimal bactericidal concentration (MBC) for 82 bacteria includingE. coli,P. aeruginosa,S. aureus,Enterococcus faecalis,Streptococcus pyogenes,Streptococcus agalactiae, and viridans streptococci. Both H2O2and OCl−destroyed RBCs at submicrobicidal concentrations. Nanomolar concentr...
Biochimica et Biophysica Acta (BBA) - General Subjects, 1996
Neutrophils form superoxide anion (02) and hydrogen peroxide (H202) and release myeloperoxidase (MPO) during ingestion of microbial pathogens. MPO, which adheres to some bacteria, catalyzes the formation of HOCI from H202, thereby enhancing H202/O 2microbicidal activity. Hydroxyl radical (HO), also is an important contributor to H202 and O2-microbicidal activity. MPO decreases iron-catalyzed HO production but also leads to HO production through the reaction of O2-and HOCI. We hypothesized that binding of MPO to bacteria could alter the magnitude and site of HO production upon organism exposure to 02-/H202. Incubation of MPO with Escherichia coli and Pseudomonas aeruginosa resulted in stable association of MPO with the bacteria which enhanced their susceptibility to killing by O2-/H202. In the absence of MPO preincubation exposure of E. coli, but not P. aeruginosa to 02-/H202, led to iron-catalyzed HO generation. This was associated with different amounts of redox active iron in the two types of bacteria. MPO preincubation slightly decreased HO detected with E. coli, but markedly increased HO formation with P. aeruginosa. This likely resulted from decreased iron-catalyzed HO production counterbalanced by increased iron-independent HO formation. MPO preincubation did not effect bacterial killing by a system which generated only H202, precluding MPO-dependent HO formation. These data are consistent with a possible role for MPO-derived HO in the augmentation of bacterial killing by this enzyme.
Antibacterial effect of lactoperoxidase and myeloperoxidase against Bacillus cereus
Antimicrobial Agents and Chemotherapy, 1985
An oral periodontopathic bacterium, Bacillus cereus, was inhibited both by lactoperoxidase (LP) and myeloperoxidase (MP) antimicrobial systems. With the LP-SCN--H2O2 system, the growth inhibition was directly proportional to the amount of OSCN- ions present. The OSCN-, which is the principal oxidation product of the LP (or MP)-SCN--H2O2 system at neutral pH, is a normal component of human saliva. The oxidation products of both peroxidase systems inhibited the growth of the bacteria. This inhibition was associated with reduced extracellular release of collagenase activity from the cells. With LP, the antimicrobial efficiency of the oxidizable substrates was SCN- greater than I-, and with MP, the efficiency was I- greater than Cl- greater than SCN-, respectively. LP did not oxidize Cl-.
Biochem J 228 583 592, 1985
Examination of the spectra of phagocytosing neutrophils and of myeloperoxidase present in the medium of neutrophils stimulated with phorbol myristate acetate has shown that superoxide generated by the cells converts both intravacuolar and exogenous myeloperoxidase into the superoxo-ferric or oxyferrous form (compound III or MPG2). A similar product was observed with myeloperoxidase in the presence of hypoxanthine, xanthine oxidase and Cl-. Both transformations were inhibited by superoxide dismutase. Thus it appears that myeloperoxidase in the neutrophil must function predominantly as this superoxide derivative. MPO2 autoxidized slowly (ts = 12min at 25°C) to the ferric enzyme. It did not react directly with H202 or Cl-, but did react with compound II (MP2+ H202). MPO2 catalysed hypochlorite formation from H202 and Clat approximately the same rate as the ferric enzyme, and both reactions showed the same H202-dependence. This suggests that MPG2 can enter the main peroxidation pathway, possibly via its reaction with compound II. Both ferric myeloperoxidase and MPG2 showed catalase activity, in the presence or absence of Cl-, which predominated over chlorination at H202 concentrations above 200 tiM. Thus, although the reaction of neutrophil myeloperoxidase with superoxide does not appear to impair its chlorinating ability, the H202 concentration in its environment will determine whether the enzyme acts primarily as a catalase or peroxidase.
Peroxidase-mediated oxygenation and microbicidal activity
Inflammation, 2000
It is known that a peroxidase, H 2 O 2 , and a halide form a "cytotoxic triad." As a result of the interactions of the components of the triad, reactive oxygen intermediates (ROI) are formed that help to destroy various invading pathogens including Candida. The present study was undertaken to determine if equivalent units of peroxidase induced equivalent levels of macrophage-mediated killing of Candida. Murine peritoneal macrophages were exposed to various concentrations of eosinophil peroxidase (EPO), myeloperoxidase (MPO), and horseradish peroxidase (HRP). Luminol-dependent chemiluminescence studies showed that equivalent units of peroxidase, as determined by oxidation of guaiacol, demonstrated a hierarchical pattern of ROI production. Macrophage phagocytosis and candidicidal activity, as measured by a fluorescence acridine orange assay, also demonstrated the same hierarchical pattern of EPO > MPO > HRP. Therefore, enzymatically equivalent peroxidases do not demonstrate equivalent candidicidal activity. These data indicate a distinct order of peroxidases relative to their ability to stimulate chemiluminescence and macrophage-mediated killing.
Evaluation of the Antimicrobial Activity of a Super Oxidized Solution in Clinical Isolates
Microbial Drug Resistance, 2015
This study evaluated the antimicrobial activity of Estericide Ò QX (super oxidized solution) in 524 bacterial clinical isolates causing nosocomial infections. The minimum inhibitory concentration (MIC) was determined by the serial broth microdilution method. The bacterial viability of the isolates and control strains was tested. The bactericidal effect of the disinfectant was determined according to the European Standards (EN) Test Methods-1040 guidelines. Assay of stability in Estericide QX after 1 year of storage was performed. The microdilution assays showed that the isolates were inhibited at concentrations of 10-40 parts per million (ppm). For grampositive bacteria, the MIC values 20 and 40 ppm were more predominant (95%), whereas for gram-negative bacteria, the MIC values 10 and 20 ppm had the highest percentage (91.7%). The difference between the two groups was statistically significant (p < 0.001). The results of the assay of bactericidal activity showed that all tested bacteria (99.999%) were killed within 30 sec of contact time. The stability test showed that Estericide QX maintained its disinfectant action over time. In conclusion, the results of the present study showed that the super oxidized solution of Estericide QX provides a high antibacterial activity on both gram-positive and gramnegative bacteria. Based on these results and under the conditions of the present study, we believe that Estericide QX can be used efficiently against multiresistant nosocomial bacteria, providing an opportunity for new disinfection alternatives.
Biochemical Journal
Examination of the spectra of phagocytosing neutrophils and of myeloperoxidase present in the medium of neutrophils stimulated with phorbol myristate acetate has shown that superoxide generated by the cells converts both intravacuolar and exogenous myeloperoxidase into the superoxo-ferric or oxyferrous form (compound III or MPG2). A similar product was observed with myeloperoxidase in the presence of hypoxanthine, xanthine oxidase and Cl-. Both transformations were inhibited by superoxide dismutase. Thus it appears that myeloperoxidase in the neutrophil must function predominantly as this superoxide derivative. MPO2 autoxidized slowly (ts = 12min at 25°C) to the ferric enzyme. It did not react directly with H202 or Cl-, but did react with compound II (MP2+ H202). MPO2 catalysed hypochlorite formation from H202 and Clat approximately the same rate as the ferric enzyme, and both reactions showed the same H202-dependence. This suggests that MPG2 can enter the main peroxidation pathway, possibly via its reaction with compound II. Both ferric myeloperoxidase and MPG2 showed catalase activity, in the presence or absence of Cl-, which predominated over chlorination at H202 concentrations above 200 tiM. Thus, although the reaction of neutrophil myeloperoxidase with superoxide does not appear to impair its chlorinating ability, the H202 concentration in its environment will determine whether the enzyme acts primarily as a catalase or peroxidase.