The Response of Antioxidant Enzyme and ATPase in Bacteria Exposed to 1,2-dichlorobenzene

The activity response of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), ATP enzyme activities of Escherichia coli Q8, Bacillus subtilis L11, and Bacillus cereus OL-1 following exposure to 1,2-dichlorobenzene (1,2-DCB) was investigated. The bacterial strains were treated with the different concentrations of 1,2-DCB. Results obtained indicated that SOD and CAT activities in the tested bacteria increased significantly in a concentration-dependent manner after different concentrations of 1,2-DCB were applied. The activity of SOD in B. subtilis was stimulated and reached the highest level after treatment with 10 mg/L 1,2-DCB for 3 h. For B.cereus OL-1, there was another stimulation of SOD activity after 1,2-DCB application for about 5 h The stimulation by 1,2-DCB showed a relative lag for E. coli. 1,2-DCB had an evident influence on ATPase activity in the three bacteria within a relatively short period. 1,2-DCB would have caused a certain oxidative stress on the three bacteria which may not only elevate SOD and CAT activities but also generate new SOD isozymes to antagonize oxidative stress. All indirectly reflect the existence of poisonous and harmful material in the environment , and can indicate the influence of pollution sensitivily. Therefore SOD, CAT and ATP enzyme activity in microbial body can be regarded as a molecular index of polluting ,which is feasible.

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617. Efficacy of Dimercaptosuccinic Acid (DMSA), a Zinc Chelator, in Combination with Imipenem Against Metallo-β-Lactamase Producing Escherichia coli in a Murine Peritonitis Model

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.685 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S287-S287

Author(s):

Geoffrey Cheminet ◽

Patrice Nordmann ◽

Francoise Chau ◽

Nicolas Kieffer ◽

Katell Peoc’h ◽

...

Keyword(s):

Escherichia Coli ◽

Maximum Effect ◽

Dependent Manner ◽

Bacterial Strains ◽

Concentration Dependent Manner ◽

Bacterial Counts ◽

E Coli ◽

Zinc Chelator ◽

Peritonitis Model

Abstract Background A strategy used by bacterial strains to resist β-lactam antibiotics is the expression of metallo-β-lactamases (MBL) requiring zinc for activity. The use of a zinc chelator may restore carbapenem activity against MBL-producing Enterobacteriaceae. DMSA is a heavy metal chelator approved in humans with a satisfactory safety record. Our objective was to evaluate the activity of DMSA in combination with carbapenems, in vitro and in a fatal murine peritonitis model, against MBL-producing Escherichia coli. Methods Isogenic derivatives of wild-type E. coli CFT073 producing the MBL NDM-1, VIM-2, IMP-1, and the serine carbapenemases OXA-48 and KPC-3 were constructed. Minimum inhibitory concentrations (MICs) of imipenem, meropenem, and ertapenem were determined against each strain alone or in combination with DMSA. Mice were infected with E. coli CFT073 or NDM-1 and treated intraperitoneally for 24 hours with imipenem 100 mg/kg every 4 hours, DMSA 200 mg/kg every 4 hours, or both. Mice survival rates and bacterial counts in peritoneal fluid (PF) and spleen were assessed at 24 hours. Results In vitro, DMSA in combination with each carbapenem permitted a significant decrease of the MICs against all MBL-producing strains, in a concentration-dependent manner. The maximum effect was found for the NDM-1 strain with a 6- to 8-fold MIC reduction, depending on the carbapenem used. NDM-1 strain became susceptible to carbapenems with concentrations of DMSA ≥6 mM. Increasing zinc concentrations above 1 mg/L (average human plasma concentration) did not alter this effect. No benefit of DMSA was observed against non-MBL strains. In vivo, when used alone, the DMSA regimen was not toxic in uninfected mice and ineffective against NDM-1-infected mice (100% mortality). Combination of imipenem and DMSA significantly reduced bacterial counts in PF and spleen as compared with imipenem alone (P < 0.001), and reduced mortality, although not significantly (11% vs. 37%, respectively, P = 0.12). No benefit of the combination was observed against CFT073. Conclusion DMSA is highly effective in vitro in reducing carbapenems MICs against MBL-producing E. coli and appears as a promising strategy in combination with carbapenems for the treatment of NDM-1-related infections. Disclosures All authors: No reported disclosures.

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Further investigation of the mechanism of Vitreoscilla hemoglobin (VHb) protection from oxidative stress in Escherichia coli

Biologia ◽

10.2478/s11756-011-0099-x ◽

2011 ◽

Vol 66 (5) ◽

Cited By ~ 2

Author(s):

Meltem Akbas ◽

Tugrul Doruk ◽

Serhat Ozdemir ◽

Benjamin Stark

Keyword(s):

Oxidative Stress ◽

Escherichia Coli ◽

Hydrogen Peroxide ◽

Superoxide Dismutase ◽

Stationary Phase ◽

Exponential Phase ◽

Vitreoscilla Hemoglobin ◽

Sod Activity ◽

E Coli ◽

Hydrogen Peroxide Treatment

AbstractIn Escherichia coli, Vitreoscilla hemoglobin (VHb) protects against oxidative stress, perhaps, in part, by oxidizing OxyR. Here this protection, specifically VHb-associated effects on superoxide dismutase (SOD) and catalase levels, was examined. Exponential or stationary phase cultures of SOD+ or SOD− E. coli strains with or without VHb and oxyR antisense were treated with 2 mM hydrogen peroxide without sublethal peroxide induction, and compared to untreated control cultures. The hydrogen peroxide treatment was toxic to both SOD+ and SOD− cells, but much more to SOD− cells; expression of VHb in SOD+ strains enhanced this toxicity. In contrast, the presence of VHb was generally associated in the SOD+ background with a modest increase in SOD activity that was not greatly affected by oxyR antisense or peroxide treatment. In both SOD+ and SOD− backgrounds, VHb was associated with higher catalase activity both in the presence and absence of peroxide. Contrary to its stimulatory effects in stationary phase, in exponential phase oxyR antisense generally decreased VHb levels.

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Dimercaptosuccinic acid in combination with carbapenems against isogenic strains of Escherichia coli producing or not producing a metallo-β-lactamase in vitro and in murine peritonitis

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkaa347 ◽

2020 ◽

Vol 75 (12) ◽

pp. 3593-3600 ◽

Cited By ~ 1

Author(s):

G Cheminet ◽

V de Lastours ◽

L Poirel ◽

F Chau ◽

K Peoc’h ◽

...

Keyword(s):

Escherichia Coli ◽

Peritoneal Fluid ◽

Dimercaptosuccinic Acid ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Bacterial Counts ◽

E Coli ◽

Time Kill ◽

Isogenic Strains

Abstract Background Carbapenemase-producing Enterobacterales represent a major therapeutic challenge. MBLs, requiring zinc at their catalytic site, could be inhibited by meso-dimercaptosuccinic acid (DMSA), a heavy metal chelator already widely used for treating lead intoxication. Objectives To evaluate the activity of carbapenems alone or combined with DMSA against MBL-producing Escherichia coli in a severe murine peritonitis model. Methods Isogenic strains of wild-type E. coli CFT073 producing the MBLs NDM-1, VIM-2 and IMP-1, and the control serine carbapenemases OXA-48 and KPC-3 were constructed. MIC determinations and time–kill assays were performed for imipenem, meropenem and ertapenem alone or in combination with DMSA. Infected mice were treated intraperitoneally for 24 h with imipenem, DMSA or their combination. Bacterial counts in peritoneal fluid and spleen were assessed at 24 h. Results DMSA in combination with each carbapenem caused a significant decrease in the MICs for all MBL-producing strains, in a concentration-dependent manner, but did not provide benefit against non-MBL strains. In mice infected with the NDM-1-producing strain, the combination of imipenem and DMSA significantly reduced bacterial counts in peritoneal fluid (P = 0.0006) and spleen (P < 0.0001), as compared with imipenem alone, with no benefit against the KPC-3-producing and CFT073 strains. DMSA concentrations in plasma of mice were comparable to those obtained in humans with a standard oral dose. Conclusions DMSA restores the activity of carbapenems against MBL-producing strains, and its combination with carbapenems appears to be a promising strategy for the treatment of NDM-producing E. coli infections.

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Escherichia coli O157 : H7 glutamate- and arginine-dependent acid-resistance systems protect against oxidative stress during extreme acid challenge

Microbiology ◽

10.1099/mic.0.022905-0 ◽

2009 ◽

Vol 155 (3) ◽

pp. 805-812 ◽

Cited By ~ 44

Author(s):

Bradley L. Bearson ◽

In Soo Lee ◽

Thomas A. Casey

Keyword(s):

Oxidative Stress ◽

Escherichia Coli ◽

Hydrogen Peroxide ◽

Acid Stress ◽

Acid Resistance ◽

Dependent Manner ◽

Bacterial Survival ◽

E Coli ◽

Stress Protection ◽

Acid Challenge

Micro-organisms may simultaneously encounter multiple stresses in their environment. To investigate the protection that several known Escherichia coli O157 : H7 acid-resistance systems might provide against both oxidative and acid stress, the addition of diamide, a membrane-permeable thiol-specific oxidizing agent, or hydrogen peroxide were used concurrent with acid challenge at pH 2.5 to determine bacterial survival. The addition of either diamide or hydrogen peroxide decreased bacterial survival in a dose-dependent manner for E. coli O157 : H7 during challenge at pH 2.5 following overnight growth in LB MES pH 5.5 (acid-resistance system 1, AR1). In contrast, the presence of either glutamate or arginine during challenge provided significant protection against diamide- and hydrogen peroxide-induced oxidative stress during pH 2.5 acid challenge. Oxidative stress protection during acid challenge required gadC and adiA for the glutamate- (AR2) and arginine- (AR3) dependent acid-resistance systems, respectively. In addition, maximal protection against oxidative stress in the presence of glutamate required a low external pH (pH 2.5), since pH 5.5 did not protect. This study demonstrates that the glutamate- and arginine-dependent acid-resistance systems of E. coli O157 : H7 can simultaneously protect against oxidative stress during extreme acid challenge.

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Use of [1-14C]oleate labelled autoclaved Escherichia coli as a membranous substrate for measurement of in vitro phospholipase D activity

Biochemistry and Cell Biology ◽

10.1139/o92-006 ◽

1992 ◽

Vol 70 (1) ◽

pp. 43-48 ◽

Cited By ~ 3

Author(s):

S. S. Ghosh ◽

Richard C. Franson

Keyword(s):

Escherichia Coli ◽

Phosphatidic Acid ◽

Phospholipase D ◽

Phospholipase A ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

E Coli ◽

Streptomyces Chromofuscus ◽

Hydrolysis Of

Autoclaved Escherichia coli labelled with [1-14C]oleate in the 2-acyl position have been used extensively to measure phospholipase A2 activity in vitro. The present study demonstrates that this membranous substrate is also useful for the measurement of in vitro phospholipase D activity. Phospholipase D from Streptomyces chromofuscus catalyzed the hydrolysis of [1-14C]oleate labelled, autoclaved E. coli optimally at pH 7.0–8.0 to generate [14C]phosphatidic acid in the presence of 5 mM added Ca2+. Other divalent cations would not substitute for Ca2+. Activity was linear with time and protein up to 30% of the hydrolysis of substrate. Phospholipase D activity was stimulated in a dose-dependent manner by the addition of Triton X-100. The activity was increased 5.5-fold with 0.05% Triton, a concentration that totally inhibited hydrolysis of E. coli by human synovial fluid phospholipase A2. Accumulation of [14C]diglyceride was observed after 10 min of incubation. This accumulation was inhibited by NaF (IC50 = 18 μM) or propanolol (IC50 = 180 μM) suggesting the S. chromofuscus phospholipase D was contaminated with phosphatidate phosphohydrolase. Phosphatidic acid released by the action of cabbage phospholipase D was converted to phosphatidylethanol in an ethanol concentration dependent manner. These results demonstrate that [1-14C]oleate labelled, autoclaved E. coli can be used to measure phospholipase D activity by monitoring accumulation of either [14C]phosphatidic acid or [14C]phosphatidylethanol.Key words: Escherichia coli, substrate, phospholipase D, Streptomyces chromofuscus, sodium fluoride, propranolol.

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Evaluation of Biological Activities of Chemically Synthesized Cobalt Oxide Nanoparticles in Concentration and Time Dependent Manner

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2020.13.6.9 ◽

2020 ◽

Vol 13 (6) ◽

pp. 5243-5249

Author(s):

Vijayta Gupta ◽

Vinay Kant ◽

Meena Sharma

Keyword(s):

Free Radicals ◽

Cobalt Oxide ◽

Biological Activities ◽

Antibacterial Properties ◽

Co3o4 Nanoparticles ◽

Dependent Manner ◽

Bacterial Strains ◽

Concentration Dependent Manner ◽

E Coli

The promising results of metal oxides nanoparticles in different areas including the biological system lead us to investigate the antioxidant and antimicrobial actions of chemically synthesized cobalt oxide (Co3O4) nanoparticles. The different concentrations of synthesized Co3O4 nanoparticles were prepared and evaluated for different parameters at different time intervals i.e. on day 1, 30 and 60 after preparations. Co3O4 nanoparticles synthesized in this study were of 52.2 nm average size with a polydispersity index of 0.465. We observed that Co3O4 nanoparticles scavenge different in vitro free radicals (DPPH, ABTS, superoxide anion and hydrogen peroxide radicals) in concentration dependent manner. The percentage of inhibitions of free radicals by Co3O4 nanoparticles was markedly more on day 1 as compared to day 30 and 60. The IC50 values of Co3O4 nanoparticles for these free radicals were also on day 1 as compared to day 30 and 60. The Co3O4 nanoparticles showed the antibacterial actions against both the bacterial strains i.e. S. aureus and E. coli. The MIC and MBC values revealed that action of Co3O4 nanoparticles was more against E. coli than S. aureus. The MIC and MBC values were lower on day 1 as compared to day 30 and 60 with respective to specific bacteria. In conclusions, the Co3O4 nanoparticles synthesized in this study showed potent antioxidant and antibacterial properties due to which it may serve as promising candidate for the combat the biological problems humans, animals and plants associated with reactive oxygen species and bacteria.

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NfiS, a species-specific regulatory noncoding RNA of Pseudomonas stutzeri, enhances oxidative stress tolerance in Escherichia coli

AMB Express ◽

10.1186/s13568-019-0881-7 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Guihua Hu ◽

Tao Hu ◽

Yuhua Zhan ◽

Wei Lu ◽

Min Lin ◽

...

Keyword(s):

Oxidative Stress ◽

Escherichia Coli ◽

Stress Responses ◽

Noncoding Rna ◽

Regulatory Networks ◽

Target Genes ◽

Pseudomonas Stutzeri ◽

Bacterial Strains ◽

E Coli ◽

Species Specific

Abstract Noncoding RNAs (ncRNAs) can finely control the expression of target genes at the posttranscriptional level in prokaryotes. Regulatory small RNAs (sRNAs) designed to control target gene expression for applications in metabolic engineering and synthetic biology have been successfully developed and used. However, the effect on the heterologous expression of species- or strain-specific ncRNAs in other bacterial strains remains poorly understood. In this work, a Pseudomonas stutzeri species-specific regulatory ncRNA, NfiS, which has been shown to play an important role in the response to oxidative stress as well as osmotic stress in P. stutzeri A1501, was cloned and transferred to the Escherichia coli strain Trans10. Recombinant NfiS-expressing E. coli, namely, Trans10-nfiS, exhibited significant enhancement of tolerance to oxidative stress. To map the possible gene regulatory networks mediated by NfiS in E. coli under oxidative stress, a microarray assay was performed to delineate the transcriptomic differences between Trans10-nfiS and wild-type E. coli under H2O2 shock treatment conditions. In all, 1184 genes were found to be significantly altered, and these genes were divided into mainly five functional categories: stress response, regulation, metabolism related, transport or membrane protein and unknown function. Our results suggest that the P. stutzeri species-specific ncRNA NfiS acts as a regulator that integrates adaptation to H2O2 with other cellular stress responses and helps protect E. coli cells against oxidative damage.

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Cytotoxic Effect of Graphene Oxide Nanoribbons on Escherichia coli

Nanomaterials ◽

10.3390/nano11051339 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1339

Author(s):

Shirong Qiang ◽

Zhengbin Li ◽

Li Zhang ◽

Dongxia Luo ◽

Rongyue Geng ◽

...

Keyword(s):

Escherichia Coli ◽

Graphene Oxide ◽

Cytotoxic Effect ◽

Lactic Dehydrogenase ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

E Coli ◽

Graphene Oxide Nanoribbons ◽

Graphene Derivatives

The biological and environmental toxicity of graphene and graphene derivatives have attracted great research interest due to their increasing applications. However, the cytotoxic mechanism is poorly understood. Here, we investigated the cytotoxic effect of graphene oxide nanoribbons (GORs) on Escherichia coli (E. coli) in an in vitro method. The fabricated GORs formed long ribbons, 200 nm wide. Based on the results of the MTT assay and plate-culture experiments, GORs significantly inhibited the growth and reproduction of E. coli in a concentration-dependent manner. We found that GORs stimulated E. coli to secrete reactive oxygen species, which then oxidized and damaged the bacterial cell membrane. Moreover, interaction between GORs and E. coli cytomembrane resulted in polysaccharide adsorption by GORs and the release of lactic dehydrogenase. Furthermore, GORs effectively depleted the metal ions as nutrients in the culture medium by adsorption. Notably, mechanical cutting by GORs was not obvious, which is quite different from the case of graphene oxide sheets to E. coli.

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Anti-Biofilm Effect of Octenidine and Polyhexanide on Uropathogenic Biofilm-Producing Bacteria

Urologia Internationalis ◽

10.1159/000512370 ◽

2021 ◽

pp. 1-7

Author(s):

Maria Loose ◽

Kurt G. Naber ◽

Larry Purcell ◽

Manfred P. Wirth ◽

Florian M.E. Wagenlehner

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

E Coli ◽

Mueller Hinton ◽

High Dilutions ◽

Artificial Urine ◽

Tract Infections ◽

Mueller Hinton Broth

Background: A catheter allowing a release of antibacterial substances such as antiseptics into the bladder could be a new way of preventing biofilm formation and subsequent catheter-associated urinary tract infections. Methods: Minimal inhibitory and bactericidal concentration (MIC/MBC) determinations in cation-adjusted Mueller-Hinton broth and artificial urine were performed for 4 antiseptics against 3 uropathogenic biofilm producers, Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis. Furthermore, effects of octenidine and polyhexanide against catheter biofilm formation were determined by quantification of biofilm-producing bacteria. Results: Sodium hypochlorite showed MIC/MBC values between 200 and 800 mg/L for all strains tested. Triclosan was efficient against E. coli and P. mirabilis (MIC ≤2.98 mg/L) but ineffective against P. aeruginosa. Octenidine and polyhexanide showed antibacterial activity against all 3 species tested (MIC 1.95–7.8 and 3.9–31.25 mg/L). Both octenidine and polyhexanide were able to prevent biofilm formation on catheter segments in a concentration dependent manner. Furthermore, adding 250 mg/L of each biocide disrupted biofilms formed by E. coli and P. mirabilis, whereas even 500 mg/L was not sufficient to completely destroy P. aeruginosa biofilms. Conclusion: Octenidine- and polyhexanide-containing antiseptics showed a broad effect against typical uropathogenic biofilm producers even in high dilutions. This study provides a basis for further investigation of the potential of octenidine and polyhexanide as prophylaxis or treatment of catheter biofilms.

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Superoxide dismutase restores the influence of nitric oxide on renal arterioles in diabetes mellitus.

Journal of the American Society of Nephrology ◽

10.1681/asn.v581559 ◽

1995 ◽

Vol 5 (8) ◽

pp. 1559-1566

Author(s):

K Ohishi ◽

P K Carmines

Keyword(s):

Nitric Oxide ◽

Diabetes Mellitus ◽

Superoxide Dismutase ◽

Early Stage ◽

Dependent Manner ◽

Superoxide Anions ◽

Sprague Dawley ◽

Sod Activity ◽

Concentration Dependent Manner ◽

Arteriolar Diameter

Experiments were performed to determine the influence of endogenous nitric oxide (NO) on basal arteriolar diameter in kidneys from diabetic rats and to evaluate the role of superoxide anions as modulators of NO activity under these conditions. Male Sprague-Dawley rats were injected with streptozotocin (STZ, 65 mg/kg i.v.) and received insulin via ip osmotic minipumps (3 U/kg per day). Sham rats received vehicle treatments. Videomicroscopy was used, in conjunction with the in vitro blood-perfused juxtamedullary nephron technique, to visualize renal afferent and efferent arterioles 2 wk after the onset of diabetes. Baseline afferent arteriolar inside diameter was greater in STZ (32 +/- 2 microns) than in sham rats (24 +/- 2 microns). Efferent arteriolar diameter did not differ between STZ (24 +/- 2 microns) and sham rats (21 +/- 1 microns). In kidneys from sham rats, N omega-nitro-L-arginine (L-NNA, an NO synthase inhibitor) decreased arteriolar diameters in a concentration-dependent manner, with 100 microM L-NNA significantly reducing both afferent (13 +/- 2%) and efferent (11 +/- 1%) diameters. In kidneys from STZ rats, 100 microM L-NNA reduced afferent and efferent diameters by only 3 +/- 1 and 4 +/- 1%, respectively, indicating a suppressed arteriolar influence of NO. In STZ kidneys treated with superoxide dismutase (SOD, 150 U/mL), afferent and efferent arteriolar L-NNA responses were restored to levels comparable to those of SOD-treated and untreated sham kidneys. These observations suggest that suppressed SOD activity reduces the tonic influence of NO on renal arterioles during the early stage of diabetes mellitus, perhaps through allowing the accumulation of NO-scavenging superoxide anions.

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