Toxicity of indole-3-acetic acid combined with horseradish peroxidase on Staphylococcus aureus (original) (raw)
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Inflammation Research, 2008
Background: Superoxide dismutase (SOD) and catalase are anti-oxidant enzymes potentially used by the bacteria to neutralize macrophage microbicidal molecules such as hydrogen peroxide (H2O2). Objective: To investigate contribution of bacterial anti-oxidant enzymes in intracellular survival of Staphylococcus aureus (S. aureus) within macrophages. Materials: Murine peritoneal macrophages and S. aureus (CMC-524, ICH-629 and ICH-757). Treatment: 106 colony forming units (CFU) of the 90 minutes (min) intracellularly viable S. aureus were administered (i.v.) per mouse through 0.1 ml saline. Methods: Anti-oxidant enzyme assay, phagocytic activity, H2O2 release, Zymography for catalase, serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) level were estimated. One-way Model I ANOVA and one tail Student’s t-test were performed. Results: Survival of S. aureus was least after 90 min of reincubation within macrophages. Maximum amount of bacterial anti-oxidant enzymes were released after 90 min of re-incubation. H2O2 released after 90 min of re-incubation with S. aureus was maximum. Higher activity of catalase and SOD by S. aureus occurred in response to the gradual production of H2O2. Serum IL-6 and TNF-α was also elevated 1h post infection. Conclusions: Bacterial catalase and SOD combat reactive oxygen species enabling S. aureus to persist within macrophages, inducing local inflammation, causing greater induction of serum TNF-α and IL-6.
Journal of Biotechnology Research Center, 2009
Thirty three isolates classified as Staphylococcus aureus were isolated from 183 different samples that included wounds, burns, boils, abscesses, ear, nose, vaginal swabs, blood, urine samples, sputum, seminal fluid and cerebrospinal fluid. The ability of these isolates to produce superoxide dismutase (SOD) was tested by using submerged culture. It has been found that the isolate S.aureus HM86 has the highest productivity of the enzyme. The optimal condition for SOD enzyme production from the isolate S.aureus HM86 by the submerged culture method were determined using (0.5 %) Mannose as carbon source and peptone (0.5%) and pancreatic digest of casein (2%) as nitrogen sources with initial pH of 7 after 12 hours of incubation at 37oC, in shaker incubator at 150 rpm and with aeration ratio (1: 6.6). It has been found that the best method for enzyme extraction is by using ultrasonication for 15 min, the optimal time for addition of paraquat at concentration of 0.5 mM is after 6 and 8 hou...
Microbiology, 2006
The response of Staphylococcus aureus to hypochlorous acid (HOCl) exposure was investigated. HOCl challenges were performed on cultures interrupted in the exponential phase. Pretreatment with HOCl conferred resistance to hydrogen peroxide in a PerR-dependent manner. Derepression of the PerR regulon was observed at low HOCl concentration (survival >50 %), using several fusions of different stress promoters to lacZ reporter genes. At least four members of the PerR regulon (katA, mrgA, bcp and trxA) encoding proteins with antioxidant properties were strongly induced following exposure to various HOCl concentrations. A striking result was the link between the derepression of the PerR regulon and the decreased superoxide dismutase (SOD) activity following exposure to increased HOCl concentrations. The sodA mutant was more resistant than the wild-type and also had a higher level of 3-phosphoglycerate dehydrogenase (a measure of PerR regulon activity) without exposure to HOCl. Together,...
Inhibition of Staphylococcus aureus by Oleuropein Is Mediated by Hydrogen Peroxide
Journal of Food Protection, 2005
The inhibition of Staphylococcus aureus by oleuropein is shown to be largely due to hydrogen peroxide production by oleuropein. The reaction is initiated by noninhibitory levels of hydrogen peroxide present as a result of tryptone oxidation in the underlying medium. Inhibition is abolished by catalase and anaerobic incubation conditions, and the effect of tryptone can be replicated by exogenous H2O2. S. aureus strains with reduced catalase activity show greater sensitivity to oleuropein. A mechanism for hydrogen peroxide production is proposed. Inhibition is not entirely due to H2O2, since some organisms with similar sensitivity to H2O2 as S. aureus were resistant to oleuropein, suggesting that there may be a cooperative effect between H2O2 and oleuropein itself.
Indian Journal of Microbiology, 2010
The present study was performed in order to carefully investigate the interaction of Staphylococcus aureus with murine macrophages and the contribution of catalase and superoxide dismutase in intracellular persistence of Staphylococcus aureus within murine macrophages during in vitro infection. We have reported that Staphylococcus aureus internalized by murine macrophages did not appear to be rapidly killed. Data indicating the contribution of a single catalase and superoxide dismutase in intracellular survival of Staphylococcus aureus were provided using established biochemical assays. The results of the present experiment suggest that the survival of Staphylococcus aureus within phagocytic cells is facilitated by its ability to resist oxidative products. Organisms in the log phase of growth clearly demonstrate a resistance to oxidative products.
International Journal of Phytoremediation, 2021
NADPH-dependent superoxide production by intact human neutrophils is inhibited by DPI (diphenyleneiodonium), when stimulated by either FMLP (N-formylmethionyl-leucyl-phenylalanine) or PMA (phorbol 12-myristate 13-acetate). Addition of 10 ,#M-DPI abolished the reduction of both the FAD and the cytochrome b components of the NADPH oxidase. DPI inhibition of the oxidase was associated with defective aerobic killing of staphylococci by human neutrophils. Anaerobic killing, phagocytosis, chemotaxis and motility were relatively unaffected by 10,uM-DPI. Degranulation of the azurophil and specific granules, induced by the soluble stimuli FMLP or PMA, and by particulate stimuli was decreased by the presence of DPI. The above effects of DPI on human neutrophils are similar to those found in chronic granulomatous disease. Bactericidal assays The Oxford strain of Staphylococcus aureus (N.C.T.C. 6571) was used in bactericidal assays. Bacteria were prepared and bactericidal assays performed as described by Williams et al. (1985), with human in place of bovine neutrophils. Lysostaphin was used to remove extracellular staphylococci in the determination of intracellular survival (Tan et al., 1971). Neutrophils (3.3 x 106/ml) and bacteria (106/ml) were suspended in 20 mM-phosphate-buffered saline (0.137 M-NaCl/2.68 mM-KCI/8. 1 mM-Na2HPO4/ 1.47 mM-KH2PO4, pH 7.0) containing 1.26 mM-CaCl2, 0.41 mM-Vol.
Journal of Bacteriology, 1999
A Staphylococcus aureus mutant (SPW1) which is unable to survive long-term starvation was shown to have a transposon insertion within a gene homologous to the sodA family of manganese-dependent superoxide dismutases (SOD). Whole-cell lysates of the parental 8325-4 strain demonstrated three zones of SOD activity by nondenaturing gel electrophoresis. The activities of two of these zones were dependent on manganese for activity and were absent in SPW1. The levels of SOD activity and sodA expression were growth-phase dependent, occurring most during postexponential phase. This response was also dependent on the level of aeration of the culture, with highest activity and expression occurring only under high aeration. Expression of sodA and, consequently, SOD activity could be induced by methyl viologen but only during the transition from exponential- to postexponential-phase growth. SPW1 was less able to survive amino acid limitation and acid stress but showed no alteration in pathogenic...
International Journal of Environmental Research and Public Health
Current study investigated effects of elevated hydrostatic pressure exposure in the presence of mild heat and natural antimicrobials against Staphylococcus aureus. Hydrostatic pressure of 350 to 550 MPa with nisin (5000 IU/mL), carvacrol, or caprylic acid (0.5% v/v) were applied for the reduction in four-strain mixture of S. aureus in HEPES buffer at 4 and 40 °C for up to 7 min. Results were statistically analyzed by ANOVA and D-values were additionally calculated using best-fitted linear model. Prior to exposure to treatments at 4 °C, counts of the pathogen were 7.95 ± 0.4 log CFU/mL and were reduced (p < 0.05) to 6.44 ± 0.3 log CFU/mL after 7 min of treatment at 450 MPa. D-value associated with this treatment was 5.34 min (R2 = 0.72). At 40 °C, counts were 8.21 ± 0.7 and 5.77 ± 0.3 log CFU/mL before and after the 7-min treatments, respectively. D-value associated with 40 °C treatment was 3.30 min (R2 = 0.62). Application of the antimicrobials provided additional pathogen reduct...
Hydrogen peroxide as a potent bacteriostatic antibiotic: Implications for host defense
Free Radical Biology and Medicine, 1995
Host defense against bacterial pathogens in higher organisms is mediated in part by the generation of reactive oxygen species (ROS) by PMN. In this study, we determined the following effects of exposure of constant concentrations of H202 on E. coli in a culture continuously monitored for H202 concentration, numbers, and viabilities of cells: (l) E. coli growth rates monitored for 1 h were profoundly affected by concentrations of H202, between 25-50 #M. (2) Complete bacteriostasis was observed at 100/~M. (3) Significant cell killing was not observed until the concentration of H202 was greater than 500 #M. (4) Bacteriostatic (25-50 #M) concentrations of H202 appeared not to be toxic to human skin fibroblasts for a 2-h exposure. (4) Bacteriostasis by H202 could not be explained by metabolic inhibition, because intracellular ATP levels were not compromised at bacteriostatic doses of H202. (5) Measurements of H202 concentrations in subcutaneous abscess fluid infected with both E. coli and S. aureus indicated prevailing concentrations of the oxidant consistent with a proposed role of H202 in host defense.
Antimicrobial Susceptibility Pattern and Biochemical Characteristics of Staphylococcus aureus: Impact of Bio field Treatment, 2015
Study background: Staphylococci are widespread in nature, mainly found on the skin and mucous membranes. Staphylococcus aureus (S. aureus) is the key organism for food poisoning due to massive production of heat stable exotoxins. The current study was attempted to investigate the effect of biofield treatment on antimicrobial susceptibility pattern and biochemical characteristics of S. aureus (ATCC 25923). Methods: S. aureus cells were procured from MicroBioLogics in sealed packs bearing the American Type Culture Collection (ATCC 25923) number and stored according to the recommended storage protocols until needed for experiments. Revived and lyophilized state of ATCC strains of S. aureus were selected for the study. Both revived (Group; Gr. II) and lyophilized (Gr. III) strain of S. aureus were subjected to Mr. Trivedi’s biofield treatment. Revived treated cells were assessed on day 5 and day 10 while lyophilized treated cells on day 10 only. After biofield treatment both treated cells were analysed for its antimicrobial sensitivity, minimum inhibitory concentration value, biochemical reactions and biotype number with respect to control (Gr. I). Results: The antimicrobial susceptibility and minimum inhibitory concentration of S. aureus showed significant (86.67%) alteration in lyophilized cells while no alteration was found in revived treated cells as compared to control. It was observed that overall 37.93% (eleven out of twenty nine) biochemical reactions were altered in the treated groups with respect to control. Moreover, biotype numbers were substantially changed in revived treated cells, Gr. II (303137, Staphylococcus capitis subsp. ureolyticus) on day 5 and in lyophilized treated cells, Gr. III (767177, S. cohnii subsp. urealyticum) on day 10 as compared to control (307016, S. aureus). Conclusion: The result suggested that biofield treatment has significant impact on S. aureus in lyophilized treated cells with respect to antimicrobial susceptibility, MIC values and biochemical reactions pattern. Apart from these, biotype numbers with new species were observed in revived treated group on day 5 as Staphylococcus capitis subsp. ureolyticus and in lyophilized cells as Staphylococcus cohnii subsp. urealyticum with respect to control, i.e., S. Aureus.