scholarly journals Supramolecular Polymerization Powered by E. coli : Fabricating an NIR Photothermal Antibacterial Agent in situ

CCS Chemistry ◽  
2021 ◽  
pp. 1-33
Author(s):  
Zihe Yin ◽  
Yuchong Yang ◽  
Jinpeng Yang ◽  
Guobin Song ◽  
Hao Hu ◽  
...  
Keyword(s):  
Antibacterial Agent ◽  
E Coli ◽  
Supramolecular Polymerization

Antibacterial Activity of Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Kyoung- Sun Seo ◽  
Seong Woo Jin ◽  
Seongkyu Choi ◽  
Kyeong Won Yun
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Agent ◽  
Methanol Extract ◽  
The Other ◽  
Diffusion Method ◽  
E Coli ◽  
Agar Diffusion ◽  
Agar Diffusion Method ◽  
Crude Methanol Extract

The antibacterial activity of three Cupressaceae plants (Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa) was tested against three bacteria using the agar diffusion method. The ether and ethylacetate fraction of crude methanol extract from the three plants showed potent antibacterial activity against the tested microorganisms. The result showed that Staphylococcus aureus revealed the most sensitivity among the tested bacteria. Thujaoccidentalisether fraction and Thujaorientalis hexane fraction exhibited the highest antibacterial activity against Staphylococcus aureus. E. coli was shown the highest MIC values compared to the other two tested bacteria, which indicates the lowest antibacterial activity against the bacterium. This study promises an interesting future for designing a potentially active antibacterial agent from the three Cupressaceae plants.

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

2020 ◽  
Author(s):  
Feifei Jia ◽  
Jie Wang ◽  
Yanyan Zhang ◽  
Qun Luo ◽  
Luyu Qi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Time Of Flight ◽  
E Coli ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Chemical Tags ◽  
Secondary Ion

<p></p><p><i>In situ</i> visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for <i>in situ </i>visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.</p><p></p>

scholarly journals DnaA, the Initiator of Escherichia coliChromosomal Replication, Is Located at the Cell Membrane

2000 ◽  
Vol 182 (9) ◽  
pp. 2604-2610 ◽  
Author(s):  
Gillian Newman ◽  
Elliott Crooke
Keyword(s):  
Cell Membrane ◽  
Spatial Organization ◽  
Active Form ◽  
Chromosomal Replication ◽  
E Coli ◽  
Dnaa Protein ◽  
Section Electron ◽  
Acidic Phospholipids

ABSTRACT Given the lack of a nucleus in prokaryotic cells, the significance of spatial organization in bacterial chromosome replication is only beginning to be fully appreciated. DnaA protein, the initiator of chromosomal replication in Escherichia coli, is purified as a soluble protein, and in vitro it efficiently initiates replication of minichromosomes in membrane-free DNA synthesis reactions. However, its conversion from a replicatively inactive to an active form in vitro occurs through its association with acidic phospholipids in a lipid bilayer. To determine whether the in situ residence of DnaA protein is cytoplasmic, membrane associated, or both, we examined the cellular location of DnaA using immunogold cryothin-section electron microscopy and immunofluorescence. Both of these methods revealed that DnaA is localized at the cell membrane, further suggesting that initiation of chromosomal replication in E. coli is a membrane-affiliated event.

scholarly journals Microchannelled alkylated chitosan sponge to treat noncompressible hemorrhages and facilitate wound healing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xinchen Du ◽  
Le Wu ◽  
Hongyu Yan ◽  
Zhuyan Jiang ◽  
Shilin Li ◽  
...  
Keyword(s):  
Wound Healing ◽  
Shape Recovery ◽  
Parenchymal Cell ◽  
Gelatin Sponge ◽  
Defect Model ◽  
Liver Parenchymal Cell ◽  
E Coli ◽  
Tissue Integration ◽  
3D Printed

AbstractDeveloping an anti-infective shape-memory hemostatic sponge able to guide in situ tissue regeneration for noncompressible hemorrhages in civilian and battlefield settings remains a challenge. Here we engineer hemostatic chitosan sponges with highly interconnective microchannels by combining 3D printed microfiber leaching, freeze-drying, and superficial active modification. We demonstrate that the microchannelled alkylated chitosan sponge (MACS) exhibits the capacity for water and blood absorption, as well as rapid shape recovery. We show that compared to clinically used gauze, gelatin sponge, CELOX™, and CELOX™-gauze, the MACS provides higher pro-coagulant and hemostatic capacities in lethally normal and heparinized rat and pig liver perforation wound models. We demonstrate its anti-infective activity against S. aureus and E. coli and its promotion of liver parenchymal cell infiltration, vascularization, and tissue integration in a rat liver defect model. Overall, the MACS demonstrates promising clinical translational potential in treating lethal noncompressible hemorrhage and facilitating wound healing.

Durable Antibacterial Finish on Cotton Fabrics with PAMAM/Ag+

2011 ◽  
Vol 332-334 ◽  
pp. 77-80 ◽  
Author(s):  
Chuan Jie Zhang ◽  
Hong Yang ◽  
Yun Liu ◽  
Ping Zhu
Keyword(s):  
Cotton Fabric ◽  
Antibacterial Agent ◽  
Antibacterial Property ◽  
Breaking Strength ◽  
Antibacterial Properties ◽  
Pamam Dendrimers ◽  
Cotton Fabrics ◽  
E Coli ◽  
Strength Retention ◽  
Better Than

Cotton fabric with excellent antibacterial properties was obtained by treated with polyamide-amine (PAMAM) dendrimers as a carrier and silver nitrate as an antibacterial agent. The antibacterial cotton fabrics were prepared by the methods of one-bath process and two-bath process. Antibacterial activity of cotton fabrics treated by two different methods was good, but the antibacterial durability of cotton fabric treated with two-bath process was better than that treated with one-bath process. After 50 washing cycles, cotton fabric treated with two-bath process still had good antibacterial property and its inhibitory rate to Gram-positive S. aureus and Gram-negative E. coli was over 99 %. It was found that the breaking strength retention of finished cotton fabrics was 85.83 % and the decrease of cotton fabrics’ whiteness index was about 15 %.

scholarly journals Enzymatic synthesis and phosphorolysis of 4(2)-thioxo- and 6(5)-azapyrimidine nucleosides by E. coli nucleoside phosphorylases

2016 ◽  
Vol 12 ◽  
pp. 2588-2601 ◽  
Author(s):  
Vladimir A Stepchenko ◽  
Anatoly I Miroshnikov ◽  
Frank Seela ◽  
Igor A Mikhailopulo
Keyword(s):  
Purine Nucleoside Phosphorylase ◽  
Reaction Conditions ◽  
E Coli ◽  
No Formation ◽  
Structural Peculiarities ◽  
Substrate Properties ◽  
Nucleoside Phosphorylases ◽  
Derivatives Of

The trans-2-deoxyribosylation of 4-thiouracil (4SUra) and 2-thiouracil (2SUra), as well as 6-azauracil, 6-azathymine and 6-aza-2-thiothymine was studied using dG and E. coli purine nucleoside phosphorylase (PNP) for the in situ generation of 2-deoxy-α-D-ribofuranose-1-phosphate (dRib-1P) followed by its coupling with the bases catalyzed by either E. coli thymidine (TP) or uridine (UP) phosphorylases. 4SUra revealed satisfactory substrate activity for UP and, unexpectedly, complete inertness for TP; no formation of 2’-deoxy-2-thiouridine (2SUd) was observed under analogous reaction conditions in the presence of UP and TP. On the contrary, 2SU, 2SUd, 4STd and 2STd are good substrates for both UP and TP; moreover, 2SU, 4STd and 2’-deoxy-5-azacytidine (Decitabine) are substrates for PNP and the phosphorolysis of the latter is reversible. Condensation of 2SUra and 5-azacytosine with dRib-1P (Ba salt) catalyzed by the accordant UP and PNP in Tris∙HCl buffer gave 2SUd and 2’-deoxy-5-azacytidine in 27% and 15% yields, respectively. 6-Azauracil and 6-azathymine showed good substrate properties for both TP and UP, whereas only TP recognizes 2-thio-6-azathymine as a substrate. 5-Phenyl and 5-tert-butyl derivatives of 6-azauracil and its 2-thioxo derivative were tested as substrates for UP and TP, and only 5-phenyl- and 5-tert-butyl-6-azauracils displayed very low substrate activity. The role of structural peculiarities and electronic properties in the substrate recognition by E. coli nucleoside phosphorylases is discussed.

scholarly journals Combining Augmented Radiotherapy and Immunotherapy through a Nano-Gold and Bacterial Outer-Membrane Vesicle Complex for the Treatment of Glioblastoma

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1661
Author(s):  
Mei-Hsiu Chen ◽  
Tse-Ying Liu ◽  
Yu-Chiao Chen ◽  
Ming-Hong Chen
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicle ◽  
Glioma Cells ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
E Coli ◽  
Tumor Bearing ◽  
Nano Gold ◽  
Gl261 Cell

Glioblastoma, formerly known as glioblastoma multiforme (GBM), is refractory to existing adjuvant chemotherapy and radiotherapy. We successfully synthesized a complex, Au–OMV, with two specific nanoparticles: gold nanoparticles (AuNPs) and outer-membrane vesicles (OMVs) from E. coli. Au–OMV, when combined with radiotherapy, produced radiosensitizing and immuno-modulatory effects that successfully suppressed tumor growth in both subcutaneous G261 tumor-bearing and in situ (brain) tumor-bearing C57BL/6 mice. Longer survival was also noted with in situ tumor-bearing mice treated with Au–OMV and radiotherapy. The mechanisms for the successful treatment were evaluated. Intracellular reactive oxygen species (ROS) greatly increased in response to Au–OMV in combination with radiotherapy in G261 glioma cells. Furthermore, with a co-culture of G261 glioma cells and RAW 264.7 macrophages, we found that GL261 cell viability was related to chemotaxis of macrophages and TNF-α production.

scholarly journals Rapid Detection, Identification, and Enumeration ofEscherichia coli Cells in Municipal Water by Chemiluminescent In Situ Hybridization

2001 ◽  
Vol 67 (1) ◽  
pp. 142-147 ◽  
Author(s):  
Henrik Stender ◽  
Adam J. Broomer ◽  
Kenneth Oliveira ◽  
Heather Perry-O'Keefe ◽  
Jens J. Hyldig-Nielsen ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
16S Rrna ◽  
Sensitivity And Specificity ◽  
Bacterial Species ◽  
Rdna Sequence ◽  
Sequence Information ◽  
Sequence Alignments ◽  
E Coli ◽  
Municipal Water

ABSTRACT A new chemiluminescent in situ hybridization (CISH) method provides simultaneous detection, identification, and enumeration of culturableEscherichia coli cells in 100 ml of municipal water within one working day. Following filtration and 5 h of growth on tryptic soy agar at 35°C, individual microcolonies of E. coliwere detected directly on a 47-mm-diameter membrane filter using soybean peroxidase-labeled peptide nucleic acid (PNA) probes targeting a species-specific sequence in E. coli 16S rRNA. Within each microcolony, hybridized, peroxidase-labeled PNA probe and chemiluminescent substrate generated light which was subsequently captured on film. Thus, each spot of light represented one microcolony of E. coli. Following probe selection based on 16S ribosomal DNA (rDNA) sequence alignments and sample matrix interference, the sensitivity and specificity of the probe Eco16S07C were determined by dot hybridization to RNA of eight bacterial species. Only the rRNA of E. coli and Pseudomonas aeruginosa were detected by Eco16S07C with the latter mismatch hybridization being eliminated by a PNA blocker probe targetingP. aeruginosa 16S rRNA. The sensitivity and specificity for the detection of E. coli by PNA CISH were then determined using 8 E. coli strains and 17 other bacterial species, including closely related species. No bacterial strains other thanE. coli and Shigella spp. were detected, which is in accordance with 16S rDNA sequence information. Furthermore, the enumeration of microcolonies of E. coli represented by spots of light correlated 92 to 95% with visible colonies following overnight incubation. PNA CISH employs traditional membrane filtration and culturing techniques while providing the added sensitivity and specificity of PNA probes in order to yield faster and more definitive results.

scholarly journals Endophytic Bacteria from Faloak Plant Seed (Sterculia comosa Wallich) as Antibacterial Agent

2018 ◽  
Vol 10 (3) ◽  
pp. 546-552
Author(s):  
Maria Yasinta Moi ◽  
Endang Kusdiyantini ◽  
Sri Pujiyanto
Keyword(s):  
Antibacterial Agent ◽  
Endophytic Bacteria ◽  
Pathogenic Bacteria ◽  
Inhibition Zone ◽  
Biochemical Properties ◽  
Rrna Gene ◽  
Plant Seed ◽  
E Coli ◽  
Antibiotic Compounds ◽  
Screening Result

Endophytic bacteria isolated from some various kind of plants are able to yield some active compounds which have a role as an antibacterial compound. This work aimed to isolate and to screen the Endophytic bacteria from Faloak seed in its charge in inhibiting two kinds of pathogenic bacteria, Staphylococcus aureus and Escherichia coli. There were six isolates of Endophytic bacteria isolated in this work. According to the screening result, one isolate which had the most potential antibacterial activity (marked by the formation of inhibition zone) against S. aureus and E. coli. That most potential isolate was then tested and identified for both biochemical properties and molecular 16S rRNA gene. The result of this study showed that the endophytic bacteria isolate of Faloak seed with the code of S1 had the similarity with Enterobacter xiangfangensis strain 10-17 by 93 %. The research about endophytic bacteria of Faloak plants was never conducted before. Thus this research was expected to give information about the potential of antimicrobial ability Faloak plants which can be utilized in the discovery of new antibiotic compounds which in the future are expected to overcome the problem of microorganism resistance to antibiotics. The use of endophytic bacteria is expected to prevents the extinction of Faloak plants due to excessive use.

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