scholarly journals Biomineralization of Platinum by Escherichia coli

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 407 ◽  
Author(s):  
Sahar Shar ◽  
Frank Reith ◽  
Esmaeil Shahsavari ◽  
Eric Adetutu ◽  
Yuana Nurulita ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Liquid Culture ◽  
Bacterial Species ◽  
Platinum Complexes ◽  
Industrial Applications ◽  
Bacterial Survival ◽  
Platinum Concentration ◽  
E Coli ◽  
The Impact ◽  
Scanning Electron

The widespread use of platinum in many industrial applications has led to its release into the environment at elevated concentrations with potential adverse effects on human and environmental health. However, the nature of interactions between mobile platinum complexes and the biotic components of the environment, which are increasingly being exposed to platinum, is poorly studied. The aim of this study was to assess the impact of Pt(IV)-chloride on the growth and activity of the well-characterized bacteria Escherichia coli. Bacterial survival and viability in the presence of different concentrations of Pt(IV)-chloride were assessed in liquid culture, while platinum retention was assessed using experimentation with sand-filled columns with the residual platinum concentration measured by atomic absorption spectroscopy. Bacterial biomineralization of platinum was studied with scanning electron microscopy. The results showed that E. coli tolerated PtCl4 at concentrations of up to 10,000 µM over 21 days and remained viable after 112 days of incubation with PtCl4 at 10,000 µM in sand columns. Overall, 74 wt.% and 50 wt.% of platinum was mineralized in E. coli and blank sand columns, respectively. The results of this study confirm that E. coli is capable of biomineralizing platinum. The results confirm that the interaction of platinum with bacteria is not limited to known metal-resistant bacterial species.

scholarly journals mcr-1 Gene Expression Modulates the Inflammatory Response of Human Macrophages to Escherichia coli

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Giorgio Mattiuz ◽  
Sabrina Nicolò ◽  
Alberto Antonelli ◽  
Tommaso Giani ◽  
Ilaria Baccani ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lipid A ◽  
Nuclear Translocation ◽  
Interleukin 12 ◽  
Bacterial Survival ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Human Macrophages ◽  
E Coli ◽  
The Impact

ABSTRACT MCR-1 is a plasmid-encoded phosphoethanolamine transferase able to modify the lipid A structure. It confers resistance to colistin and was isolated from human, animal, and environmental strains of Enterobacteriaceae, raising serious global health concerns. In this paper, we used recombinant mcr-1-expressing Escherichia coli to study the impact of MCR-1 products on E. coli-induced activation of inflammatory pathways in activated THP-1 cells, which was used as a model of human macrophages. We found that infection with recombinant mcr-1-expressing E. coli significantly modulated p38-MAPK and Jun N-terminal protein kinase (JNK) activation and pNF-κB nuclear translocation as well as the expression of genes for the relevant proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-12 (IL-12), and IL-1β compared with mcr-1-negative strains. Caspase-1 activity and IL-1β secretion were significantly less activated by mcr-1-positive E. coli strains than the mcr-1-negative parental strain. Similar results were obtained with clinical isolates of mcr-1-positive E. coli, suggesting that, in addition to colistin resistance, the expression of mcr-1 allows the escape of early host innate defenses and may promote bacterial survival.

scholarly journals Preparation of multilayer polyelectrolyte ceramic membrane for water disinfection

2020 ◽  
Vol 20 (8) ◽  
pp. 3207-3215
Author(s):  
Mohamed Boussemghoune ◽  
Chikhi Mustapha ◽  
Yasin Ozay ◽  
Nadir Dizge
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ceramic Membrane ◽  
Ceramic Membranes ◽  
Water Disinfection ◽  
Clay Material ◽  
Test Results ◽  
E Coli ◽  
The Impact ◽  
Scanning Electron

Abstract A multilayer polyelectrolyte ceramic membrane using LbL was assembled to test the performance of water disinfection capability. The natural raw clay material (kaolin) was used as the main ceramic membrane (CM) support. The impact of the number of polyelectrolyte bilayers (2, 4, 6) on the retention of Escherichia coli was systematically investigated. Test results showed the water permeability coefficients (Lp) were 85.3 L/m2.h.bar and 69.5, 28.3, 50.1 L/m2.h.bar for pristine (CM0) and ceramic membranes with two bilayers (CM2), four bilayers (CM4), and six bilayers (CM6), respectively. Complete retention of E. coli was achieved by the multilayer polyelectrolyte ceramic membrane with four bilayers. The surface morphology of the multilayer polyelectrolyte ceramic membrane was identified by scanning electron microscopy (SEM). The results showed that the multilayer polyelectrolyte ceramic membrane can be safely applied in providing water disinfection.

Effect of hydrogen peroxide on antibacterial activities of Canadian honeys

2006 ◽  
Vol 52 (12) ◽  
pp. 1228-1237 ◽  
Author(s):  
Katrina Brudzynski
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Specific Activity ◽  
Bacterial Species ◽  
Antibacterial Activities ◽  
Therapeutic Effects ◽  
E Coli ◽  
The Impact

Honey is recognized as an efficacious topical antimicrobial agent in the treatment of burns and wounds. The antimicrobial activity in some honeys depends on the endogenous hydrogen peroxide content. This study was aimed to determine whether honey's hydrogen peroxide level could serve as a honey-specific, activity-associated biomarker that would allow predicting and assessing the therapeutic effects of honey. Using a broth microdilution assay, I analyzed antibacterial activities of 42 Canadian honeys against two bacterial strains: Escherichia coli (ATCC 14948) and Bacillus subtilis (ATCC 6633). The MIC90 and MIC50 were established from the dose-response relationship between antibacterial activities and honey concentrations. The impact of H2O2 on antibacterial activity was determined (i) by measuring the levels of H2O2 before and after its removal by catalase and (ii) by correlating the results with levels of antibacterial activities. Canadian honeys demonstrated moderate to high antibacterial activity against both bacterial species. Both MIC90 and MIC50 revealed that the honeys exhibited a selective growth inhibitory activity against E. coli, and this activity was strongly influenced by endogenous H2O2 concentrations. Bacillus subtilis activity was marginally significantly correlated with H2O2 content. The removal of H2O2 by catalase reduced the honeys' antibacterial activity, but the enzyme was unable to completely decompose endogenous H2O2. The 25%-30% H2O2 "leftover" was significantly correlated with the honeys' residual antibacterial activity against E. coli. These data indicate that all Canadian honeys exhibited antibacterial activity, with higher selectivity against E. coli than B. subtilis, and that these antibacterial activities were correlated with hydrogen peroxide production in honeys. Hydrogen peroxide levels in honey, therefore, is a strong predictor of the honey's antibacterial activity.Key words: honey, antibacterial activity, hydrogen peroxide, catalase, Escherichia coli, Bacillus subtilis.

scholarly journals Impact of mcr-1 on the Development of High Level Colistin Resistance in Klebsiella pneumoniae and Escherichia coli

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao-Qing Zhu ◽  
Yi-Yun Liu ◽  
Renjie Wu ◽  
Haoliang Xun ◽  
Jian Sun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Bacterial Species ◽  
Survival Rates ◽  
Genetic Alterations ◽  
Colistin Resistance ◽  
E Coli ◽  
High Concentrations ◽  
High Level ◽  
The Impact

Plasmid-mediated colistin resistance gene mcr-1 generally confers low-level resistance. The purpose of this study was to investigate the impact of mcr-1 on the development of high-level colistin resistance (HLCR) in Klebsiella pneumoniae and Escherichia coli. In this study, mcr-1-negative K. pneumoniae and E. coli strains and their corresponding mcr-1-positive transformants were used to generate HLCR mutants via multiple passages in the presence of increasing concentrations of colistin. We found that for K. pneumoniae, HLCR mutants with minimum inhibitory concentrations (MICs) of colistin from 64 to 1,024 mg/L were generated. Colistin MICs increased 256- to 4,096-fold for mcr-1-negative K. pneumoniae strains but only 16- to 256-fold for the mcr-1-harboring transformants. For E. coli, colistin MICs increased 4- to 64-folds, but only 2- to 16-fold for their mcr-1-harboring transformants. Notably, mcr-1 improved the survival rates of both E. coli and K. pneumoniae strains when challenged with relatively high concentrations of colistin. In HLCR K. pneumoniae mutants, amino acid alterations predominately occurred in crrB, followed by phoQ, crrA, pmrB, mgrB, and phoP, while in E. coli mutants, genetic alterations were mostly occurred in pmrB and phoQ. Additionally, growth rate analyses showed that the coexistence of mcr-1 and chromosomal mutations imposed a fitness burden on HLCR mutants of K. pneumoniae. In conclusion, HLCR was more likely to occur in K. pneumoniae strains than E. coli strains when exposed to colistin. The mcr-1 gene could improve the survival rates of strains of both bacterial species but could not facilitate the evolution of high-level colistin resistance.

scholarly journals The Protein Interactome of Glycolysis in Escherichia coli

Proteomes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 16
Author(s):  
Shomeek Chowdhury ◽  
Stephen Hepper ◽  
Mudassir K. Lodi ◽  
Milton H. Saier ◽  
Peter Uetz
Keyword(s):  
Escherichia Coli ◽  
Protein Interactions ◽  
Allosteric Regulation ◽  
Glycolytic Enzymes ◽  
Protein Protein Interactions ◽  
Post Translational Modification ◽  
Interacting Protein ◽  
E Coli ◽  
Protein Interactome ◽  
The Impact

Glycolysis is regulated by numerous mechanisms including allosteric regulation, post-translational modification or protein-protein interactions (PPI). While glycolytic enzymes have been found to interact with hundreds of proteins, the impact of only some of these PPIs on glycolysis is well understood. Here we investigate which of these interactions may affect glycolysis in E. coli and possibly across numerous other bacteria, based on the stoichiometry of interacting protein pairs (from proteomic studies) and their conservation across bacteria. We present a list of 339 protein-protein interactions involving glycolytic enzymes but predict that ~70% of glycolytic interactors are not present in adequate amounts to have a significant impact on glycolysis. Finally, we identify a conserved but uncharacterized subset of interactions that are likely to affect glycolysis and deserve further study.

scholarly journals Solubility assessment of single-chain antibody fragment against epithelial cell adhesion molecule extracellular domain in four Escherichia coli strains

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Fatemeh Sadat Javadian ◽  
Majid Basafa ◽  
Aidin Behravan ◽  
Atieh Hashemi
Keyword(s):  
Escherichia Coli ◽  
Cell Adhesion ◽  
Epithelial Cell ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Extracellular Domain ◽  
Epithelial Cell Adhesion Molecule ◽  
Single Chain ◽  
E Coli ◽  
The Impact

Abstract Background Overexpression of the EpCAM (epithelial cell adhesion molecule) in malignancies makes it an attractive target for passive immunotherapy in a wide range of carcinomas. In comparison with full-length antibodies, due to the small size, the scFvs (single-chain variable fragments) are more suitable for recombinant expression in E. coli (Escherichia coli). However, the proteins expressed in large amounts in E. coli tend to form inclusion bodies that need to be refolded which may result in poor recovery of bioactive proteins. Various engineered strains were shown to be able to alleviate the insolubility problem. Here, we studied the impact of four E. coli strains on the soluble level of anti-EpEX-scFv (anti-EpCAM extracellular domain-scFv) protein. Results Although results showed that the amount of soluble anti-EpEX-scFv obtained in BL21TM (DE3) (114.22 ± 3.47 mg/L) was significantly higher to those produced in the same condition in E. coli RosettaTM (DE3) (71.39 ± 0.31 mg/L), and OrigamiTM T7 (58.99 ± 0.44 mg/L) strains, it was not significantly different from that produced by E. coli SHuffleTM T7 (108.87 ± 2.71 mg/L). Furthermore, the highest volumetric productivity of protein reached 318.29 ± 26.38 mg/L in BL21TM (DE3). Conclusions Although BL21TM (DE3) can be a suitable strain for high-level production of anti-EpEX-scFv protein, due to higher solubility yield (about 55%), E. coli SHuffleTM T7 seems to be better candidate for soluble production of scfv compared to BL21TM (DE3) (solubility yield of about 30%).

scholarly journals Characterization of Escherichia coli Strains Derived from Cow Milk of Subclinical and Clinical Cases of Mastitis

2021 ◽  
Vol 11 (2) ◽  
pp. 541
Author(s):  
Katarzyna Grudlewska-Buda ◽  
Krzysztof Skowron ◽  
Ewa Wałecka-Zacharska ◽  
Natalia Wiktorczyk-Kapischke ◽  
Jarosław Bystroń ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Economic Problem ◽  
Cow Milk ◽  
P Value ◽  
Dairy Herds ◽  
E Coli ◽  
Bonferroni Test

Mastitis is a major economic problem in dairy herds, as it might decrease fertility, and negatively affect milk quality and milk yield. Out of over 150 bacterial species responsible for the udder inflammation, Escherichia coli is one of the most notable. This study aimed to assess antimicrobial susceptibility, resistance to dipping agents and biofilm formation of 150 E. coli strains isolated from milk of cows with subclinical and clinical mastitis. The strains came from three dairy herds located in Northern and Central Poland. The statistical analyses were performed with post-hoc Bonferroni test and chi-square test (including Yates correction). The data with a p value of <0.05 were considered significant. We found that the tested strains were mostly sensitive to antimicrobials and dipping agents. It was shown that 37.33% and 4.67% of strains were resistant and moderately resistant to at least one antimicrobial agent, respectively. No extended-spectrum beta-lactamases (ESBL)-producing E. coli were detected. The majority of strains did not possess the ability to form biofilm or formed a weak biofilm. The strong biofilm formers were found only among strains derived from cows with subclinical mastitis. The lowest bacteria number was noted for subclinical mastitis cows’ strains, after stabilization with iodine (3.77 log CFU × cm−2) and chlorhexidine (3.96 log CFU × cm−2) treatment. In the present study, no statistically significant differences in susceptibility to antibiotics and the ability to form biofilm were found among the strains isolated from cows with subclinical and clinical mastitis. Despite this, infections in dairy herds should be monitored. Limiting the spread of bacteria and characterizing the most common etiological factors would allow proper treatment.

Toxicity of the First Ten MEIC Chemicals to Bacteria

1993 ◽  
Vol 21 (2) ◽  
pp. 151-155
Author(s):  
Gustaw Kerszman
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Linear Regression ◽  
Minimal Inhibitory Concentration ◽  
Blood Concentration ◽  
Inhibitory Concentration ◽  
Human Lymphocytes ◽  
Bacterial Species ◽  
E Coli ◽  
Mild Toxicity

The toxicity of the first ten MEIC chemicals to Escherichia coli and Bacillus subtilis was examined. Nine of the chemicals were toxic to the bacteria, with the minimal inhibitory concentration (MIC) ranging from 10-3 to 4.4M. The sensitivities of both organisms were similar, but the effect on E. coli was often bactericidal, while it was bacteriostatic for B. subtilis. Digoxin was not detectably toxic to either bacterial species. Amitriptyline and FeSO4 were relatively less toxic to the bacteria than to human cells. For seven chemicals, a highly significant linear regression was established between log MIC in bacteria and log of blood concentration, giving lethal and moderate/mild toxicity in humans, as well as with toxicity to human lymphocytes.

scholarly journals Impact of Vacuum Cooling on Escherichia coli O157:H7 Infiltration into Lettuce Tissue

2008 ◽  
Vol 74 (10) ◽  
pp. 3138-3142 ◽  
Author(s):  
Haiping Li ◽  
Mehrdad Tajkarimi ◽  
Bennie I. Osburn
Keyword(s):  
Escherichia Coli ◽  
Risk Assessment ◽  
Reduction Rate ◽  
Escherichia Coli O157 ◽  
Surface Sterilization ◽  
E Coli ◽  
Green Industry ◽  
Vacuum Cooling ◽  
The Impact

ABSTRACT Vacuum cooling is a common practice in the California leafy green industry. This study addressed the impact of vacuum cooling on the infiltration of Escherichia coli O157:H7 into lettuce as part of the risk assessment responding to the E. coli O157:H7 outbreaks associated with leafy green produce from California. Vacuum cooling significantly increased the infiltration of E. coli O157:H7 into the lettuce tissue (2.65E+06 CFU/g) compared to the nonvacuumed condition (1.98E+05 CFU/g). A stringent surface sterilization and quadruple washing could not eliminate the internalized bacteria from lettuce. It appeared that vacuuming forcibly changed the structure of lettuce tissue such as the stomata, suggesting a possible mechanism of E. coli O157:H7 internalization. Vacuuming also caused a lower reduction rate of E. coli O157:H7 in stored lettuce leaves than that for the nonvacuumed condition.

scholarly journals Impact of Extended-Spectrum β-Lactamase Production on Treatment Outcomes of Acute Pyelonephritis Caused by Escherichia coli in Patients without Health Care-Associated Risk Factors

2015 ◽  
Vol 59 (4) ◽  
pp. 1962-1968 ◽  
Author(s):  
Sun Hee Park ◽  
Su-Mi Choi ◽  
Dong-Gun Lee ◽  
Sung-Yeon Cho ◽  
Hyo-Jin Lee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Health Care ◽  
Treatment Outcomes ◽  
Acute Pyelonephritis ◽  
Esbl Production ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
The Impact

ABSTRACTExtended-spectrum β-lactamase-producingEscherichia coli(ESBL-EC) is increasingly identified as a cause of acute pyelonephritis (APN) among patients without recent health care contact, i.e., community-associated APN. This case-control study compared 75 cases of community-associated ESBL-EC APN (CA-ESBL) to 225 controls of community-associated non-ESBL-EC APN (CA-non-ESBL) to identify the risk factors for ESBL-EC acquisition and investigate the impact of ESBL on the treatment outcomes of community-associated APN (CA-APN) caused byE. coliat a Korean hospital during 2007 to 2013. The baseline characteristics were similar between the cases and controls; the risk factors for ESBL-EC were age (>55 years), antibiotic use within the previous year, and diabetes with recurrent APN. The severity of illness did not differ between CA-ESBL and CA-non-ESBL (Acute Physiology and Chronic Health Evaluation [APACHE] II scores [mean ± standard deviation], 7.7 ± 5.9 versus 6.4 ± 5.3;P= 0.071). The proportions of clinical (odds ratio [OR], 1.76; 95% confidence interval [CI], 0.57 to 5.38;P= 0.323) and microbiological (OR, 1.16; 95% CI, 0.51 to 2.65;P= 0.730) cures were similar, although the CA-ESBL APN patients were less likely to receive appropriate antibiotics within 48 h. A multivariable Cox proportional hazards analysis of the prognostic factors for CA-APN caused byE. colishowed that ESBL production was not a significant factor for clinical (hazard ratio [HR], 0.39; 95% CI, 0.12 to 1.30;P= 0.126) or microbiological (HR, 0.49; 95% CI, 0.21 to 1.12;P= 0.091) failure. The estimates did not change after incorporating weights calculated using propensity scores for acquiring ESBL-EC. Therefore, ESBL production did not negatively affect treatment outcomes among patients with community-associatedE. coliAPN.

Sign in / Sign up

Export Citation Format

Share Document