The Ethanolic Leaf Extracts of Dissotis multiflora (Sm) Triana and Paullinia pinnata Linn Exert Inhibitory Effect on Escherichia coli Through Membrane Permeabilization, Loss of Intracellular Material, and DNA Fragmentation

Background: Dissotis multiflora (Sm) Triana and Paullinia pinnata Linn are widely used in Cameroonian traditional medicine to treat infectious diseases. These plants were found to be a reservoir of antioxidant and antimicrobial agents and have the potential to be used in clinic. Objective: To determine the mechanism of action of the ethanolic leaves extracts of Dissotis multiflora and Paullinia pinnata on Escherichia coli. Methodology: The microbroth dilution method was used to determine the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of D. multiflora and P. pinnata ethanolic leaves extracts. The above samples were tested for their rate of killing of E. coli cells at 1 MIC and 2 MICs. Sorbitol protection, outer membrane permeability, loss of 260-nm-absorbing material, fluorescence microscopy, and DNA degradation assay were used to examine the ultrastructural changes in bacteria induced by the extracts. Results: D. multiflora and P. pinnata extracts inhibited bacterial growth with MICs of 390.62 and 781.25 µg/mL respectively, while the MBCs values were found to be 781.25 and 1562.5 µg/mL respectively. Treatment with extracts had shorter kill-time in a time-dependent manner with effect most pronounced at 2 MICs than 1 MIC. The MIC of D. multiflora increased 4x from 390.62 µg/mL after 24 h of incubation to 1562.5 µg/mL after 7 days in the presence of an osmoprotectant indicating the inhibition of synthesis of cell wall constituents. P. pinnata had no effect on cell wall. Both extracts exhibited the greatest leakage and release of DNA materials at 30, 60, 90, and 120 min in concentration-dependent manner. Treated groups had higher values than control. At low concentrations (1/2 MIC and 1 MIC), these extracts effectively permeate the intact outer membrane of Gram-negative bacteria. Both extract were implicated in DNA fragmentation. Moreover, fluorescent cells observed further confirmed its inhibitory effect against the tested pathogen. The antibacterial action involved disruption of membrane potential, increase of membrane permeabilization, leakage of cellular material, and death suggesting them to be an alternative to antibiotics. Conclusion: These findings contribute to the understanding of the antibacterial inhibitory effect of D. multiflora and P. pinnata.

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The Effect of Antimicrobial Drugs Tylocolinum, Tetragold and Cidisept-o on Escherichia coli Ultrastructure

Sustainable Agriculture Research ◽

10.5539/sar.v2n3p65 ◽

2013 ◽

Vol 2 (3) ◽

pp. 65

Author(s):

A. G. Shakhov ◽

D. V. Fedosov ◽

L. Y. Sashnina ◽

O. V. Kazimirov

Keyword(s):

Escherichia Coli ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Water Solution ◽

Uranyl Acetate ◽

Chemotherapeutic Agents ◽

Control Culture ◽

New Drugs ◽

Ultrastructural Changes ◽

The Impact

As a result of wide antibiotics, sulfonamides and other antimicrobial agents usage for the therapy of the animals with the bacterial infections caused by various causative agents including Escherichia coli, many microorganisms gained resistance to the chemotherapeutic agents. New combined drugs are being worked out during recent years, the components of which have various influence mechanisms on the bacterial cell that helps to provide resistance forming control. The results of the researches of the new antimicrobial agents, containing antibiotics in their composition, and non-antibiotic agent influence on the ultrastructure of Escherichia coli are represented in this study. 5-hour Escherichia coli 866 culture was processed by the drugs of the minimum bactericidal (Tylocolinum-0.39 µg/ml, Tetragold-6.25 µg/ml, Cidisept-o-25 µg/ml) and 4-time concentrations during 3 hours. Samples and control culture (without drugs) were fixed by the 2.5% glutaricdialdehyde on the s-Collidine Buffer, dehydrated in the ethanol with rising concentration, filled in epoxies. Ultrathin slices were stained by 2% water solution of uranyl acetate and lead citrate for 10 minutes. Then they were examined with the use of the electron microscope JEM-100 CX II by JEOL. The research showed deep ultrastructural changes in Escherichia coli cells under the antimicrobial agent influence determined by synergistic effect of combined Tylocolinum and Tetragold drugs components, possessing various bacteria influencing mechanisms, and aldehyde that is a component of Cidisept-o. The electron microscopy usage allows to get unique information about the impact consequences of the traditional improved drugs and new drugs with antimicrobial activity on the bacterial infectious agents.

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BaeR participates in cephalosporins susceptibility by regulating the expression level of outer membrane proteins in Escherichia coli

The Journal of Biochemistry ◽

10.1093/jb/mvaa100 ◽

2020 ◽

Author(s):

Shuaiyang Wang ◽

Chunbo You ◽

Fareed Qumar Memon ◽

Geyin Zhang ◽

Yawei Sun ◽

...

Keyword(s):

Escherichia Coli ◽

Membrane Proteins ◽

Outer Membrane ◽

Efflux Pump ◽

Outer Membrane Proteins ◽

Expression Level ◽

Antibiotics Resistance ◽

Dilution Method ◽

Expression Levels ◽

E Coli

Abstract The two-component system BaeSR participates in antibiotics resistance of Escherichia coli. To know whether the outer membrane proteins involve in the antibiotics resistance mediated by BaeSR, deletion of acrB was constructed and the recombined plasmid p-baeR was introduced into E. coli K12 and K12△acrB. Minimum inhibitory concentrations (MICs) of antibacterial agents were determined by 2-fold broth micro-dilution method. Gene expressions related with major outer membrane proteins and multidrug efflux pump-related genes were determined by real-time quantitative reverse transcription polymerase chain reaction. The results revealed that the MICs of K12ΔacrB to the tested drugs except for gentamycin and amikacin decreased 2- to 16.75-folds compared with those of K12. When BaeR was overexpressed, the MICs of K12ΔacrB/p-baeR to ceftiofur and cefotaxime increased 2.5- and 2-fold, respectively, compared with their corresponding that of K12△acrB. At the same time, the expression levels of ompC, ompF, ompW, ompA and ompX showed significant reduction in K12ΔacrB/p-baeR as compared with K12△acrB. Moreover, the expression levels of ompR, marA, rob and tolC also significantly ‘decreased’ in K12ΔacrB/p-baeR. These findings indicated that BaeR overproduction can decrease cephalosporins susceptibility in acrB-free E. coli by decreasing the expression level of outer membrane proteins.

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Metal selectivity by the virulence-associated yersiniabactin metallophore system

Metallomics ◽

10.1039/c4mt00341a ◽

2015 ◽

Vol 7 (6) ◽

pp. 1011-1022 ◽

Cited By ~ 30

Author(s):

Eun-Ik Koh ◽

Chia S. Hung ◽

Kaveri S. Parker ◽

Jan R. Crowley ◽

Daryl E. Giblin ◽

...

Keyword(s):

Escherichia Coli ◽

Outer Membrane ◽

Membrane Receptor ◽

Dependent Manner ◽

Outer Membrane Receptor ◽

System P ◽

Metal Selectivity

Metal–yersiniabactin complexes are transported intact through the outer membrane receptor, FyuA, in a TonB-dependent manner in uropathogenicEscherichia coli.

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Extracellular Ca2+ transients affect poly-(R)-3-hydroxybutyrate regulation by the AtoS-AtoC system in Escherichia coli

Biochemical Journal ◽

10.1042/bj20081169 ◽

2009 ◽

Vol 417 (3) ◽

pp. 667-672 ◽

Cited By ~ 17

Author(s):

Marina C. Theodorou ◽

Ekaterini Tiligada ◽

Dimitrios A. Kyriakidis

Keyword(s):

Escherichia Coli ◽

Channel Blocker ◽

Inhibitory Effect ◽

Dependent Manner ◽

Signal Transduction System ◽

Two Component System ◽

Component System ◽

E Coli ◽

Two Component ◽

Membrane Bound

Escherichia coli is exposed to wide extracellular concentrations of Ca2+, whereas the cytosolic levels of the ion are subject to stringent control and are implicated in many physiological functions. The present study shows that extracellular Ca2+ controls cPHB [complexed poly-(R)-3-hydroxybutyrate] biosynthesis through the AtoS-AtoC two-component system. Maximal cPHB accumulation was observed at higher [Ca2+]e (extracellular Ca2+ concentration) in AtoS-AtoC-expressing E. coli compared with their ΔatoSC counterparts, in both cytosolic and membrane fractions. The reversal of EGTA-mediated down-regulation of cPHB biosynthesis by the addition of Ca2+ and Mg2+ was under the control of the AtoS-AtoC system. Moreover, the Ca2+-channel blocker verapamil reduced total and membrane-bound cPHB levels, the inhibitory effect being circumvented by Ca2+ addition only in atoSC+ bacteria. Histamine and compound 48/80 affected cPHB accumulation in a [Ca2+]e-dependent manner directed by the AtoS-AtoC system. In conclusion, these data provide evidence for the involvement of external Ca2+ on cPHB synthesis regulated by the AtoS-AtoC two-component system, thus linking Ca2+ with a signal transduction system, most probably through a transporter.

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The active repertoire of Escherichia coli peptidoglycan amidases varies with physiochemical environment

10.1101/2020.10.19.344754 ◽

2020 ◽

Author(s):

Elizabeth A. Mueller ◽

Abbygail G. Iken ◽

Mehmet Ali Öztürk ◽

Mirko Schmitz ◽

Barbara Di Ventura ◽

...

Keyword(s):

Escherichia Coli ◽

Cell Wall ◽

Cell Separation ◽

Antimicrobial Agents ◽

Model Organism ◽

Growth Conditions ◽

Low Ph ◽

E Coli ◽

Ph Dependent ◽

Stimulation Of

ABSTRACTNearly all bacteria are encased in a peptidoglycan cell wall, an essential crosslinked matrix of polysaccharide strands and short peptide stems. In the Gram-negative model organism Escherichia coli, more than forty cell wall synthases and autolysins coordinate the growth and division of the peptidoglycan sacculus in the periplasm. The precise contribution of many of these enzymes to cell wall metabolism remains unclear due to significant apparent redundancy, particularly among the cell wall autolysins. E. coli produces three major LytC-type-N-acetylmuramoyl-L-alanine amidases, which share a role in separating the newly formed daughter cells during cytokinesis. Here, we reveal two of the three amidases exhibit growth medium-dependent changes in activity. Specifically, we report acidic growth conditions stimulate AmiB—and to a lesser extent, AmiC—activity. Combining computational and genetic analysis, we demonstrate that low pH-dependent stimulation of AmiB requires three periplasmic amidase activators: EnvC, NlpD, and YgeR. Altogether, our findings support overlapping, but not redundant, roles for the E. coli amidases in cell separation and illuminate the physiochemical environment as an important mediator of cell wall enzyme activity.IMPORTANCEPenicillin and related β-lactam antibiotics targeting the bacterial cell wall synthesis are among the most commonly prescribed antimicrobials worldwide. However, rising rates of antibiotic resistance and tolerance jeopardize their continued clinical use. Development of new cell wall active therapeutics, including those targeting cell wall autolysins, has been stymied in part due to high levels of apparent enzymatic redundancy. In this study, we report a subset of E. coli amidases involved in cell separation during cell division are not redundant and instead are preferentially active during growth in distinct pH environments. Specifically, we discover E. coli amidases AmiB and AmiC are activated by acidic pH. Three semi-redundant periplasmic regulators—NlpD, EnvC, and YgeR—collectively mediate low pH-dependent stimulation of amidase activity. This discovery contributes to our understanding of how the cell wall remains robust across diverse environmental conditions and reveals opportunities for the development of condition-specific antimicrobial agents.

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Factor H Is Bound by Outer Membrane-Displayed Carbohydrate Metabolism Enzymes of Extraintestinal Pathogenic Escherichia coli and Contributes to Opsonophagocytosis Resistance in Bacteria

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2020.592906 ◽

2021 ◽

Vol 10 ◽

Author(s):

Yu Sun ◽

Bin Xu ◽

Xiangkai Zhuge ◽

Fang Tang ◽

Xuhang Wang ◽

...

Keyword(s):

Escherichia Coli ◽

Membrane Proteins ◽

Outer Membrane ◽

Binding Assay ◽

Outer Membrane Proteins ◽

Factor H ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Metabolism Enzymes ◽

Elisa Plate

Extraintestinal pathogenic Escherichia coli (ExPEC) causes bloodstream infections in humans and animals. Complement escape is a prerequisite for bacteria to survive in the bloodstream. Factor H (FH) is an important regulatory protein of the complement system. In this study, ExPEC was found to bind FH from serum. However, the mechanisms of ExPEC binding to FH and then resistance to complement-mediated attacks remain unclear. Here, a method that combined desthiobiotin pull-down and liquid chromatography-tandem mass spectrometry was used to identify the FH-binding membrane proteins of ExPEC. Seven identified proteins, which all were carbohydrate metabolic enzymes (CMEs), including acetate kinase, fructose-bisphosphate aldolase, fumarate reductase flavoprotein subunit, L-lactate dehydrogenase, dihydrolipoamide dehydrogenase, phosphoenolpyruvate synthase, and pyruvate dehydrogenase, were verified to recruit FH from serum using GST pull-down and ELISA plate binding assay. The ELISA plate binding assay determined that these seven proteins bind to FH in a dose-dependent manner. Magnetic beads coupled with any one of seven proteins significantly reduced the FH recruitment of ExPEC (p < 0.05) Subsequently, immunofluorescence, colony blotting, and Western blotting targeting outer membrane proteins determined that these seven CMEs were located on the outer membrane of ExPEC. Furthermore, the FH recruitment levels and C3b deposition levels on bacteria were significantly increased and decreased in an FH-concentration-dependent manner, respectively (p < 0.05). The FH recruitment significantly enhanced the ability of ExPEC to resist the opsonophagocytosis of human macrophage THP-1 in an FH-concentration-dependent manner (p < 0.05), which revealed a new mechanism for ExPEC to escape complement-mediated killing. The identification of novel outer membrane-displayed CMEs which played a role in the FH recruitment contributes to the elucidation of the molecular mechanism of ExPEC pathogenicity.

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Proteome Analysis of Virulence Factor Regulated by Autoinducer-2–like Activity in Escherichia coli O157:H7

Journal of Food Protection ◽

10.4315/0362-028x-70.2.300 ◽

2007 ◽

Vol 70 (2) ◽

pp. 300-307 ◽

Cited By ~ 22

Author(s):

YOUNGHOON KIM ◽

SANGNAM OH ◽

EUN YOUNG AHN ◽

JEE-YOUNG IMM ◽

SEJONG OH ◽

...

Keyword(s):

Escherichia Coli ◽

Pathogenic Bacteria ◽

Antimicrobial Agents ◽

Proteome Analysis ◽

Protein Translation ◽

Escherichia Coli O157 ◽

Dependent Manner ◽

Two Dimensional Gel Electrophoresis ◽

E Coli ◽

Autoinducer 2

Many pathogenic bacteria, including Escherichia coli O157:H7, can control gene expression in a cell density–dependent manner by producing small signaling molecules (autoinducers) in a process known as quorum sensing. In this study, the effects of the autoinducer-2–like activity on the expression of proteins, including virulence factors, in E. coli O157:H7 were characterized by proteomic analysis. Compared with the control, E. coli O157:H7 strains in the presence of autoinducer-2–like activity exhibited elevated virulence by more rapidly forming cell aggregates on epithelial cells and rapidly killing the nematode Caenorhabditis elegans, the surrogate host. Two-dimensional gel electrophoresis revealed 18 proteins that were upregulated by autoinducer-2–like activity and 4 proteins that were down-regulated. These proteins were further characterized by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry and are involved in the metabolic process, adaptation and protection, cell motility, secretion, envelope biogenesis, and protein translation. These results indicate that the newly identified proteins are associated with the control of virulence in E. coli O157:H7 and that these proteins can be potential targets for the development of antibiotics and other antimicrobial agents.

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NlpD links cell wall remodeling and outer membrane invagination during cytokinesis in Escherichia coli

PLoS Genetics ◽

10.1371/journal.pgen.1006888 ◽

2017 ◽

Vol 13 (7) ◽

pp. e1006888 ◽

Cited By ~ 42

Author(s):

Mary-Jane Tsang ◽

Anastasiya A. Yakhnina ◽

Thomas G. Bernhardt

Keyword(s):

Escherichia Coli ◽

Cell Wall ◽

Outer Membrane ◽

Membrane Invagination ◽

Cell Wall Remodeling

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Assessment of Antimicrobial Effect of Alcohol and Aqueous Extracts of Garcinia kola on Staphylococcus aureus, Bacillus cereus, Escherichia coli and Klebsiella pneumonia

Journal of Applied Sciences and Environmental Management ◽

10.4314/jasem.v24i9.5 ◽

2020 ◽

Vol 24 (9) ◽

pp. 1519-1522

Author(s):

A. Banso ◽

B.F. Banso ◽

A.A. Koleola

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Bacillus Cereus ◽

Plant Extracts ◽

Antimicrobial Agents ◽

Antimicrobial Effect ◽

Inhibitory Effect ◽

Klebsiella Pneumonia ◽

Garcinia Kola ◽

Development Of Resistance

As a result of the development of resistance of microorganisms to older antimicrobial agents there is need for a search for new agents, which are effective for the treatment of infections. The crude aqueous and alcoholic extr acts of Garcinia kola fruits were assayed against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Klebsiella pneumoniae. The results revealed that the plant extracts possess inhibitory effect against the microorganisms tested. The minimum inhibitory concentration of the plant extracts ranged between 20mg/ml and 45mg/ml. There was a change in the antibacterial activity of the test extracts on variation of temperature. The results obtained may suggest that the plant extract is thermal stable and could serve as a source of industrial drugs useful in chemotherapy of some microbial infections. Keywords: Garcinia kola, microorganisms, inhibitory, chemotherapy, drug

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Mining RNA-Seq Data to Depict How Penicillium digitatum Shapes Its Transcriptome in Response to Nanoemulsion

Frontiers in Nutrition ◽

10.3389/fnut.2021.724419 ◽

2021 ◽

Vol 8 ◽

Author(s):

Ruopeng Yang ◽

Xiu Chen ◽

Qiang Huang ◽

Chuying Chen ◽

Kannan R. R. Rengasamy ◽

...

Keyword(s):

Antifungal Activity ◽

Antimicrobial Agents ◽

Antimicrobial Properties ◽

Inhibitory Effect ◽

Penicillium Digitatum ◽

Fruit Rot ◽

Economic Losses ◽

Cellular Respiration ◽

Dependent Manner ◽

Rna Seq

Penicillium digitatum is the most severe pathogen that infects citrus fruits during storage. It can cause fruit rot and bring significant economic losses. The continuous use of fungicides has resulted in the emergence of drug-resistant strains. Consequently, there is a need to develop naturally and efficiently antifungal fungicides. Natural antimicrobial agents such as clove oil, cinnamon oil, and thyme oil can be extracted from different plant parts. They exhibited broad-spectrum antimicrobial properties and have great potential in the food industry. Here, we exploit a novel cinnamaldehyde (CA), eugenol (EUG), or carvacrol (CAR) combination antifungal therapy and formulate it into nanoemulsion form to overcome lower solubility and instability of essential oil. In this study, the antifungal activity evaluation and transcriptional profile of Penicillium digitatum exposed to compound nanoemulsion were evaluated. Results showed that compound nanoemulsion had a striking inhibitory effect on P. digitatum in a dose-dependent manner. According to RNA-seq analysis, there were 2,169 differentially expressed genes (DEGs) between control and nanoemulsion-treated samples, including 1,028 downregulated and 1,141 upregulated genes. Gene Ontology (GO) analysis indicated that the DEGs were mainly involved in intracellular organelle parts of cell component: cellular respiration, proton transmembrane transport of biological process, and guanyl nucleotide-binding molecular function. KEGG analysis revealed that metabolic pathway, biosynthesis of secondary metabolites, and glyoxylate and dicarboxylate metabolism were the most highly enriched pathways for these DEGs. Taken together, we can conclude the promising antifungal activity of nanoemulsion with multiple action sites against P. digitatum. These outcomes would deepen our knowledge of the inhibitory mechanism from molecular aspects and exploit naturally, efficiently, and harmlessly antifungal agents in the citrus postharvest industry.

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