Gold Nanoparticle Biosynthesis by E. coli and Conjugation with Streptomycin and Evaluation of its Antibacterial Effect

2014 ◽  
Vol 10 (4) ◽  
pp. 553-561 ◽  
Author(s):  
Samaneh Mazdeh ◽  
Hossein Motamedi ◽  
Azim Khiavi ◽  
Mohammad Mehrabi
Keyword(s):  
Gold Nanoparticle ◽  
Antibacterial Effect ◽  
E Coli ◽  
Nanoparticle Biosynthesis

Optimization of Gold Nanoparticle Biosynthesis by Escherichia coli DH5α and its Conjugation with Gentamicin

2015 ◽  
Vol 32 ◽  
pp. 93-105 ◽  
Author(s):  
Hossein Motamedi ◽  
Samaneh Khademi Mazdeh ◽  
Azim Akbarzadeh Khiavi ◽  
Mohammad Reza Mehrabi
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Targeted Drug Delivery ◽  
Anaerobic Bacteria ◽  
Natural Resistance ◽  
In Vivo Studies ◽  
Optimum Conditions ◽  
E Coli ◽  
Nanoparticle Biosynthesis

Metal nanoparticles are one option for targeted drug delivery. In order to increase antibiotic efficiency and decrease its side effects, antibiotic conjugated nanoparticles have been known as a suitable approach. The aim of this study was optimization of gold nanoparticle biosynthesis byEscherichia coliDH5α and its conjugation with gentamicin. For this purpose gold nanoparticles were biosynthesized from HAuCl4and confirmed by Uv/ Vis, XRD, DLS and SEM. Then the effects of different parameters on optimum conditions for gold nanoparticles production were investigated. The MIC and MBC of gentamicin and its conjugate were investigated againstE. coli,Clostridium perfringensandClostridium botulinum. The results revealed that among different treatments, centrifuge (10000 rpm, 10 min) and sonication are the optimum conditions for gold nanoparticle production with less than 10 nm sizes. Filtration was also the best method for purifying nanoparticles. The conjugated nanoparticles significantly reduced the MIC of gentamicin againstE. coliand also overcame the natural resistance of tested anaerobic bacteria. In conclusion, the optimized method is an effective, inexpensive and environmental friendly method for biosynthesis of gold nanoparticles. Overcoming natural resistance of anaerobic bacteria using antibiotic conjugates with nanoparticles provides hopes for further experiments and in vivo studies.

scholarly journals Enhanced Extracellular Synthesis of Gold Nanoparticles by Soluble Extracts from Escherichia coli Transformed with Rhizobium tropici Phytochelatin Synthase Gene

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 472
Author(s):  
Qunying Yuan ◽  
Manjula Bomma ◽  
Zhigang Xiao
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Synthesis Method ◽  
Nanoparticle Synthesis ◽  
Morphological Properties ◽  
Phytochelatin Synthase ◽  
Rhizobium Tropici ◽  
Whole Cells ◽  
E Coli ◽  
Recombinant Cells

Phytochelatins, the enzymatic products of phytochelatin synthase, play a principal role in protecting the plants from heavy metal and metalloid toxicity due to their ability to scavenge metal ions. In the present study, we investigated the capacity of soluble intracellular extracts from E. coli cells expressing R. tropici phytochelatin synthase to synthesize gold nanoparticle. We discovered that the reaction mediated by soluble extracts from the recombinant E. coli cells had a higher yield of gold nanoparticles, compared to that from the control cells. The compositional and morphological properties of the gold nanoparticles synthesized by the intracellular extracts from recombinant cells and control cells were similar. In addition, this extracellular nanoparticle synthesis method produced purer gold nanoparticles, avoiding the isolation of nanoparticles from cellular debris when whole cells are used to synthesize nanoparticles. Our results suggested that phytochelatins can improve the efficiency of gold nanoparticle synthesis mediated by bacterial soluble intracellular extracts, and the potential of extracellular nanoparticle synthesis platform for the production of nanoparticles in large quantity and pure form is worth further investigation.

scholarly journals 3D-Printed Nanocellulose-Based Cushioning–Antibacterial Dual-Function Food Packaging Aerogel

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3543
Author(s):  
Wei Zhou ◽  
Jiawei Fang ◽  
Shuwei Tang ◽  
Zhengguo Wu ◽  
Xiaoying Wang
Keyword(s):  
3D Printing ◽  
Food Packaging ◽  
Fruits And Vegetables ◽  
Antibacterial Effect ◽  
Dual Function ◽  
Printing Technology ◽  
E Coli ◽  
3D Printing Technology ◽  
The Core ◽  
3D Printed

Cushioning and antibacterial packaging are the requirements of the storage and transportation of fruits and vegetables, which are essential for reducing the irreversible quality loss during the process. Herein, the composite of carboxymethyl nanocellulose, glycerin, and acrylamide derivatives acted as the shell and chitosan/AgNPs were immobilized in the core by using coaxial 3D-printing technology. Thus, the 3D-printed cushioning–antibacterial dual-function packaging aerogel with a shell–core structure (CNGA/C–AgNPs) was obtained. The CNGA/C–AgNPs packaging aerogel had good cushioning and resilience performance, and the average compression resilience rate was more than 90%. Although AgNPs was slowly released, CNGA/C–AgNPs packaging aerogel had an obvious antibacterial effect on E. coli and S. aureus. Moreover, the CNGA/C–AgNPs packaging aerogel was biodegradable. Due to the customization capabilities of 3D-printing technology, the prepared packaging aerogel can be adapted to more application scenarios by accurately designing and regulating the microstructure of aerogels, which provides a new idea for the development of food intelligent packaging.

scholarly journals Comparative Study of Ag Nanostructures: Molecular Simulations, Electrochemical Behavior, and Antibacterial Effect

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Álvaro de Jesús Ruíz-Baltazar ◽  
Simón Yobanny Reyes-López ◽  
D. Larrañaga ◽  
R. Pérez
Keyword(s):  
Cyclic Voltammetry ◽  
Ethylene Glycol ◽  
Comparative Study ◽  
Sodium Borohydride ◽  
Electrochemical Behavior ◽  
Antibacterial Effect ◽  
Chemical Reduction ◽  
Molecular Simulations ◽  
The Other ◽  
E Coli

Nanoparticles of Ag with different sizes and structures were obtained and studied. Two methods for reductions of Ag ions were employed, chemical reduction by sodium borohydride and ethylene glycol. Cuboctahedral and icosahedral structures were obtained. Molecular simulations were carried out in order to evaluate the reactivity of both structures. On the other hand, the electrochemical activity and antibacterial effect (E. coli) of the cuboctahedral and icosahedral structures were measured experimentally. The results obtained by molecular simulation, cyclic voltammetry, and antibacterial effect were compared and discussed in this work.

Antibacterial Effect of Monocaprylin on Escherichia coli O157:H7 in Apple Juice

2005 ◽  
Vol 68 (9) ◽  
pp. 1895-1899 ◽  
Author(s):  
MANOJ KUMAR MOHAN NAIR ◽  
HANEM ABOUELEZZ ◽  
THOMAS HOAGLAND ◽  
KUMAR VENKITANARAYANAN
Keyword(s):  
Escherichia Coli ◽  
Apple Juice ◽  
Antibacterial Effect ◽  
Storage Temperature ◽  
Escherichia Coli O157 ◽  
Organoleptic Properties ◽  
E Coli ◽  
Low Concentrations ◽  
Storage Temperatures ◽  
Control Samples

The antibacterial effect of low concentrations of monocaprylin on Escherichia coli O157:H7 in apple juice was investigated. Apple juice alone (control) or containing 2.5 mM (0.055%) or 5 mM monocaprylin was inoculated with a five-strain mixture of E. coli O157:H7 at ~6.0 log CFU/ml. The juice samples were stored at 23 or 4°C for 14 or 21 days, respectively, and the population of E. coli O157:H7 was determined on tryptic soy agar plates supplemented with 0.6% yeast extract. At both storage temperatures, the population of E. coli O157:H7 in monocaprylin-supplemented juice samples was significantly lower (P < 0.05) than that in the control samples. The concentration of monocaprylin and the storage temperature had a significant effect on the inactivation of E. coli O157:H7 in apple juice. Monocaprylin at 5 mM was significantly more effective than 2.5 mM monocaprylin for killing E. coli O157:H7 in apple juice. Inactivation of E. coli O157:H7 by monocaprylin was more pronounced in juice stored at 23°C than in the refrigerated samples. Results of this study indicated that monocaprylin is effective for killing E. coli O157:H7 in apple juice, but detailed sensory studies are needed to determine the organoleptic properties of apple juice containing monocaprylin.

scholarly journals Photothermal-assisted antibacterial application of GO-Ag against clinical isolated MDR E. coli

2019 ◽  
Author(s):  
Yuqing Chen ◽  
Wei Wu ◽  
Zeqiao Xu ◽  
Cheng Jiang ◽  
Shuang Han ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Near Infrared ◽  
Antibacterial Effect ◽  
Luria Bertani ◽  
Fluorescent Imaging ◽  
Photothermal Effect ◽  
Antibacterial Efficiency ◽  
E Coli ◽  
Morphology Characterization

Abstract Background: Treatment of multidrug-resistant (MDR) bacterial infection is a great challenge in public health. Herein, we provide a solution to this problem with the use of graphene oxide-silver (GO-Ag) nanocomposites as anti-bacterial agent. Methods: Following established protocols, silver nanoparticles were grown on graphene oxide sheets. Then, a series of in-vitro studies were conducted to validate the antibacterial efficiency of the GO-Ag nanocomposites against clinical MDR Escherichia coli (E. coli) strains. Firstly, minimum inhibitory concentrations (MICs) of different antimicrobials were tested against MDR E. Coli strains. Then, bacteria viability assessments were conducted with different nanomaterials in Luria-Bertani (LB) broth. Afterwards, photothermal irradiation was conducted on MDR E. coli with lower GO-Ag concentration. At last, fluorescent imaging and morphology characterization using scanning electron microscope (SEM) were done to find the possible cause of antibacterial effect. Results: GO-Ag nanocomposites showed the highest antibacterial efficiency among tested antimicrobials. Synergetic antibacterial effect was observed in GO-Ag nanocomposites treated group. The remained bacteria viabilities were 4.4% and 4.1% respectively for different bacteria strains with GO-Ag concentration at 14.0 µg mL-1. In addition, GO-Ag nanocomposites have strong absorption in the near-infrared field and can convert the electromagnetic energy to heat. With the use of this photothermal effect, effective sterilization could be achieved using GO-Ag nanocomposites concentration as low as 7.0 µg mL-1. Fluorescent imaging and morphology characterization were used to analyze bacteria living status, which uncovered that bacteria integrity was disrupted after GO-Ag nanocomposites treatment. Conclusions: GO-Ag nanocomposites are proved to be efficient antibacterial agent against multi-drug resistant E. coli. Their strong antibacterial effect arises from inherent antibacterial property and photothermal effect that provides aid for bacteria killing.

scholarly journals Advisability of using early generation Cephalosporines for prevention and treatment of postpartum infection

2017 ◽  
Vol 66 (3) ◽  
pp. 71-74
Author(s):  
Nikolay A. Korobkov
Keyword(s):  
Antibacterial Effect ◽  
Penetration Rate ◽  
Venous Blood ◽  
Uterine Cavity ◽  
Surgical Site Infections ◽  
Lime Treatment ◽  
Early Generation ◽  
E Coli ◽  
Highperformance Liquid Chromatography

Introduction: the following research investigates an availability of a long-lime treatment of postpartum infection by using of Cephalozolin (the Cephalosporine of generation I). Matherials and Methods. Lochia samples were obtained from the uterine cavities of 21 puerperal women who did not receive drug after delivery and were cultured for the identification and the determination of the susceptibilities of the clinical isolates to Cephalozolin. The concentrations of Cephalozolin in the supernatants were measured by highperformance liquid chromatography. Results. We determined the sensivity of the most clinically important bacteria to Cephazoline and its penetration rate to the uterine cavity. We found out the following bacteria which are sensible to Cephazoline – S. agalactiae, E. coli, K. pneumoniae, E. aerogenes. A low rate of Cephazoline ≤ 0,78 mg/ml was inhibited the growth of mentioned above bacteria. Cephazoline is also active as for S. aureus – MIC90 and was equal 3.13 mg/ml. In 3 hours after the injection of 1.0 gr of Cephazoline there was a maximum concentration in a venous blood – 1.63 mg/ml. The concentration of Cephazoline in lochia was rising gradually and it maximum in the uterus cavity in 5 hours was 1.26 mg/ml, and then its slowly went down. Conclusions. The mention above results let us suggest that Cephazoline is penetrates actively to lochia and its still has a good antibacterial effect. Cephazoline is still a treatment of choice as for prevention and a treatment of postpartum surgical site infections by a sensitive microorganism.

scholarly journals Antibacterial Shoe Insole-Coated CuO-ZnO Nanocomposite Synthesized by the Sol-Gel Technique

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Nguyen Lam Uyen Vo ◽  
Thi Thuy Van Nguyen ◽  
Tri Nguyen ◽  
Phung Anh Nguyen ◽  
Van Minh Nguyen ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Antibacterial Effect ◽  
Sol Gel ◽  
Average Particle Size ◽  
Point Of Zero Charge ◽  
Average Particle ◽  
E Coli ◽  
High Antibacterial Activity ◽  
Gel Technique ◽  
Shoe Insoles

In this study, CuO-ZnO composite was synthesized via the sol-gel method using oxalic acid to form the medium complex and its applications in antibacterial have been conducted with B. cereus, E. coli, S. aureus, Salmonella, and P. aeruginosa. Then, nanopowder of CuO-ZnO was coated on shoe insoles and their antibacterial effect with S. aureus was tested. The nanocomposite products were characterized by XRD, XPS, SEM, TEM, and UV-Vis. The results showed that the CuO-ZnO composite has the average particle size in a range of 20-50 nm, the point of zero charge of 7.8, and the bandgap of 1.7 eV. XPS result shows the composite structure with Cu2+ in the product. The minimum inhibitory concentration (MIC) of CuO-ZnO nanocomposite was 0.313 mg·mL-1 for S. aureus and Samonella, 0.625 mg·mL-1 for E. coli, and 5 mg·mL-1 for B. cereus and P. aeruginosa. The shoe insoles coated with 0.35 wt.% of CuO-ZnO nanocomposite also had high antibacterial activity against S. aureus, and this antibacterial nanocomposite was implanted durably on the surface of the shoe insoles.

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