scholarly journals Cubic nano-silver-decorated manganese dioxide micromotors: enhanced propulsion and antibacterial performance

Nanoscale ◽  
2020 ◽  
Vol 12 (38) ◽  
pp. 19655-19664
Author(s):  
Wenjuan Liu ◽  
Hongbin Ge ◽  
Xiaoyong Ding ◽  
Xiaolong Lu ◽  
Yanan Zhang ◽  
...  
Keyword(s):  
Manganese Dioxide ◽  
Nano Silver ◽  
E Coli ◽  
Rapid Movement ◽  
Antibacterial Performance ◽  
Novel Strategy ◽  
Synergistic Reaction

A novel strategy for combating bacteria is proposed based on MnO2@Ag micromotors. Due to synergistic reaction of MnO2 and Ag, rapid movement was realized and an enhanced E. coli death was achieved by coupling intense motion with Ag+ sterilization.

scholarly journals An Assessment of the Viability of Lytic Phages and Their Potency against Multidrug Resistant Escherichia coli O177 Strains under Simulated Rumen Fermentation Conditions

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 265
Author(s):  
Peter Kotsoana Montso ◽  
Caven Mguvane Mnisi ◽  
Collins Njie Ateba ◽  
Victor Mlambo
Keyword(s):  
Escherichia Coli ◽  
Rumen Fluid ◽  
Multidrug Resistant ◽  
Rumen Fermentation ◽  
Ruminal Fermentation ◽  
Fermentation Conditions ◽  
E Coli ◽  
Cell Counts ◽  
Milk Contamination ◽  
Novel Strategy

Preslaughter starvation and subacute ruminal acidosis in cattle are known to promote ruminal proliferation of atypical enteropathogenic Escherichia coli strains, thereby increasing the risk of meat and milk contamination. Using bacteriophages (henceforth called phages) to control these strains in the rumen is a potentially novel strategy. Therefore, this study evaluated the viability of phages and their efficacy in reducing E. coli O177 cells in a simulated ruminal fermentation system. Fourteen phage treatments were allocated to anaerobic serum bottles containing a grass hay substrate, buffered (pH 6.6–6.8) bovine rumen fluid, and E. coli O177 cells. The serum bottles were then incubated at 39 °C for 48 h. Phage titres quadratically increased with incubation time. Phage-induced reduction of E. coli O177 cell counts reached maximum values of 61.02–62.74% and 62.35–66.92% for single phages and phage cocktails, respectively. The highest E. coli O177 cell count reduction occurred in samples treated with vB_EcoM_366B (62.31%), vB_EcoM_3A1 (62.74%), vB_EcoMC3 (66.67%), vB_EcoMC4 (66.92%), and vB_EcoMC6 (66.42%) phages. In conclusion, lytic phages effectively reduced E. coli O177 cells under artificial rumen fermentation conditions, thus could be used as a biocontrol strategy in live cattle to reduce meat and milk contamination in abattoirs and milking parlours, respectively.

scholarly journals Green Synthesis and Incorporation of Sericin Silver Nanoclusters into Electrospun Ultrafine Cellulose Acetate Fibers for Anti-Bacterial Applications

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1411
Author(s):  
Mujahid Mehdi ◽  
Huihui Qiu ◽  
Bing Dai ◽  
Raja Fahad Qureshi ◽  
Sadam Hussain ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Green Synthesis ◽  
Cellulose Acetate ◽  
Antibacterial Properties ◽  
Vital Role ◽  
Silver Nanoclusters ◽  
Composite Fibers ◽  
E Coli ◽  
Antibacterial Performance ◽  
Field Emission Electron Microscopy

Fiber based antibacterial materials have gained an enormous attraction for the researchers in these days. In this study, a novel Sericin Encapsulated Silver Nanoclusters (sericin-AgNCs) were synthesized through single pot and green synthesis route. Subsequently these sericin-AgNCs were incorporated into ultrafine electrospun cellulose acetate (CA) fibers for assessing the antibacterial performance. The physicochemical properties of sericin-AgNCs/CA composite fibers were investigated by transmission electron microscopy (TEM), field emission electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and wide X-ray diffraction (XRD). The antibacterial properties of sericin-AgNCs/CA composite fibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were systematically evaluated. The results showed that sericin-AgNCs incorporated in ultrafine CA fibers have played a vital role for antibacterial activity. An amount of 0.17 mg/mL sericin-AgNCs to CA fibers showed more than 90% results and elevated upto >99.9% with 1.7 mg/mL of sericin-AgNCs against E. coli. The study indicated that sericin-AgNCs/CA composite confirms an enhanced antibacterial efficiency, which could be used as a promising antibacterial product.

Optimization and Characterization of Biogenic Silver Nanoparticles Synthesized by Leaves Extract of Alphonsea Madraspatana

2021 ◽  
Vol 17 ◽  
Author(s):  
Amita Sahu ◽  
Sudhanshu Shekhar Swain ◽  
Goutam Ghosh ◽  
Deepak Pradhan ◽  
Dipak Kumar Sahu ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Volume Ratio ◽  
Xrd Analysis ◽  
Biofilm Inhibition ◽  
Nano Silver ◽  
E Coli ◽  
Biogenic Silver Nanoparticles ◽  
Icp Ms ◽  
Anti Oxidant

Background: Literature evidences as well as traditional uses of genus Alphonsea reveal significant antimicrobial and anti-oxidant activity, which encourages to consider A. madraspatana to have potent antimicrobials, there by offering potential adjuncts to synthesize improved antimicrobial Silver nanoparticles (AgNPs). The objective of the present exposition is to optimize reaction parameters to synthesize antimicrobial Biogenic Silver nanoparticles (BAgNPs) from extract of A. madraspatana leaves (AML) and to evaluate the effect against bacteria. Methods: BAgNPs was synthesized by optimized reaction. The Synthesized nanoparticles were characterized by UV, IR, ICP-MS and XRD analysis. The antibacterial potency of optimized BAgNPs was evaluated against E. coli by comparing with positive controls. Results: Results of optimization process indicate nanoscale BAgNPs were produced at operating temp. of 45°C for 120 min at pH 8 with 1:5 volume ratio of AgNO3 and extract. Optimized BAgNPs exhibits relatively higher antimicrobial activity (31±1mm) compared to Ciprofloxacin (27±1mm) and marketed nano silver (28± 2 mm). The developed BAgNPs shows comparable biofilm inhibition (86.50%) as compared to marketed nano silver (88.10%) and Ciprofloxacin (83.10%). Conclusion: Experimental evidence suggests methanolic extract of AML under predefined conditions successfully generate nano-template of silver with better antibacterial response against E. coli.

Silver-Supporting Diatomite Preparation and Antibacterial Performance Test

2011 ◽  
Vol 694 ◽  
pp. 742-745 ◽  
Author(s):  
Fen E Hu ◽  
Zhi Juan Wang ◽  
Jun Li Li
Keyword(s):  
Performance Test ◽  
Silver Content ◽  
Antimicrobial Effect ◽  
X Ray Diffraction ◽  
E Coli ◽  
Agno3 Solution ◽  
Antibacterial Performance ◽  
Reaction Solution ◽  
Vacuum Heating ◽  
Dipping Time

The silver-supporting diatomite was prepared by the vacuum heating decomposition method with diatomite as the carrier and AgNO3 solution as the reaction solution. Its structure was characterized by X-ray diffraction (XRD). The factors influencing silver content of diatomite have been discussed in prepared silver-supporting diatomite. The results show that when the mass ratio of diatomite to AgNO3 is 10:1, the dipping time of 2 hours and the decomposing temperature of 350°C are suitable to preparing silver-supporting diatomite. XRD analyses show that the Ag loaded on the surface and micropore of the diatomite is nano-silver. The antimicrobial effect of silver-supporting diatomite was investigated against Escherichia coli (E. coli). The results show that the silver-supporting diatomite have obvious inhibiting effect on E. coli and its minimum inhibitory concentration decrease with increase of its silver content. The silver-supporting diatomite with the silver content of 1.46% is suitable to kill E. coli in water.

scholarly journals Antibacterial Property of Composites of Reduced Graphene Oxide with Nano-Silver and Zinc Oxide Nanoparticles Synthesized Using a Microwave-Assisted Approach

2019 ◽  
Vol 20 (21) ◽  
pp. 5394 ◽  
Author(s):  
Yi-Huang Hsueh ◽  
Chien-Te Hsieh ◽  
Shu-Ting Chiu ◽  
Ping-Han Tsai ◽  
Chia-Ying Liu ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Reductase Activity ◽  
Chemical Reduction ◽  
Membrane Integrity ◽  
Zno Nps ◽  
Nano Silver ◽  
E Coli ◽  
Microwave Assisted

Graphene oxide (GO) composites with various metal nanoparticles (NPs) are attracting increasing interest owing to their broad scope in biomedical applications. Here, microwave-assisted chemical reduction was used to deposit nano-silver and zinc oxide NPs (Ag and ZnO NPs) on the surface of reduced GO (rGO) at the following weight percentages: 5.34% Ag/rGO, 7.49% Ag/rGO, 6.85% ZnO/rGO, 16.45% ZnO/rGO, 3.47/34.91% Ag/ZnO/rGO, and 7.08/15.28% Ag/ZnO/rGO. These materials were tested for antibacterial activity, and 3.47/34.91% Ag/ZnO/rGO and 7.08/15.28% Ag/ZnO/rGO exhibited better antibacterial activity than the other tested materials against the gram-negative bacterium Escherichia coli K12. At 1000 ppm, both these Ag/ZnO/rGO composites had better killing properties against both E. coli K12 and the gram-positive bacterium Staphylococcus aureus SA113 than Ag/rGO and ZnO/rGO did. RedoxSensor flow cytometry showed that 3.47/34.91% Ag/ZnO/rGO and 7.08/15.28% Ag/ZnO/rGO decreased reductase activity and affected membrane integrity in the bacteria. At 100 ppm, these two composites affected membrane integrity more in E. coli, while 7.08/15.28% Ag/ZnO/rGO considerably decreased reductase activity in S. aureus. Thus, the 3.47/34.91% and 7.08%/15.28% Ag/ZnO/rGO nanocomposites can be applied not only as antibacterial agents but also in a variety of biomedical materials such as sensors, photothermal therapy, drug delivery, and catalysis, in the future.

scholarly journals Photocatalytic Antibacterial Performance of Glass Fibers Thin Film Coated with N-DopedSnO2/TiO2

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Peerawas Kongsong ◽  
Lek Sikong ◽  
Sutham Niyomwas ◽  
Vishnu Rachpech
Keyword(s):  
Glass Fibers ◽  
Anatase Phase ◽  
Sol Gel ◽  
Composite Films ◽  
Salmonella Typhi ◽  
Dip Coating ◽  
Water Disinfection ◽  
E Coli ◽  
Antibacterial Performance ◽  
Coating Methods

Both N-doped and undoped thin films of 3SnO2/TiO2composite were prepared, by sol-gel and dip-coating methods, and then calcined at 600°C for 2 hours. The films were characterized by FTIR, XRD, UV-Vis, SEM, and XPS, and their photocatalytic activities to degrade methylene blue in solution were determined, expecting these activities to correlate with the inactivation of bacteria, which was confirmed. The doped and undoped films were tested for activities against Gram-negativeEscherichia coli(E. coli) andSalmonella typhi(S. typhi), and Gram-positiveStaphylococcus aureus(S. aureus). The effects of doping on these composite films included reduced energy band gap, high crystallinity of anatase phase, and small crystallite size as well as increased photocatalytic activity and water disinfection efficiency.

scholarly journals Enhanced Photocatalytic Antibacterial Properties of TiO2 Nanospheres with Rutile/Anatase Heterophase Junctions and the Archival Paper Protection Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2585
Author(s):  
Yingying Qin ◽  
Xinyu Wang ◽  
Pengyuan Qiu ◽  
Jian Tian
Keyword(s):  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Bet Surface Area ◽  
High Yield ◽  
Potential Candidate ◽  
Radical Oxygen Species ◽  
E Coli ◽  
Simulated Solar Light ◽  
Antibacterial Performance ◽  
Chemical Annealing

TiO2 has been generally studied for photocatalytic sterilization, but its antibacterial activities are limited. Herein, TiO2 nanospheres with rutile/anatase heterophase junctions are prepared by a wet chemical/annealing method. The large BET surface area and pore size are beneficial for the absorption of bacteria. The rutile/anatase heterojunctions narrow the bandgap, which enhances light absorption. The rutile/anatase heterojunctions also efficiently promote the photogenerated carriers’ separation, finally producing a high yield of radical oxygen species, such as •O2– and •OH, to sterilize bacteria. As a consequence, the obtained TiO2 nanospheres with rutile/anatase heterojunctions present an improved antibacterial performance against E. coli (98%) within 3 h of simulated solar light irradiation, exceeding that of TiO2 nanospheres without annealing (amorphous) and TiO2 nanospheres annealing at 350 and 550 °C (pure anatase). Furthermore, we design a photocatalytic antibacterial spray to protect the file paper. Our study reveals that the TiO2 nanospheres with rutile/anatase heterojunctions are a potential candidate for maintaining the durability of paper in the process of archival protection.

scholarly journals Evaluating the Antimicrobial Properties of Commercial Hand Sanitizers

mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
M. Chojnacki ◽  
C. Dobrotka ◽  
R. Osborn ◽  
W. Johnson ◽  
M. Young ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Benzalkonium Chloride ◽  
Bacterial Pathogens ◽  
Antimicrobial Properties ◽  
World Health ◽  
Antimicrobial Efficacy ◽  
Content Type ◽  
E Coli ◽  
Antibacterial Performance ◽  
Antimicrobial Performance

ABSTRACT Hand sanitizers have been developed as a convenient means to decontaminate an individual’s hands of bacterial pathogens in situations in which soap and water are not available. Yet to our knowledge, no study has compared the antibacterial efficacy of a large collection of hand sanitizers. Using zone of growth inhibition and kill curve assays, we assessed the performance of 46 commercially available hand sanitizers that were obtained from national chain big-box stores, gasoline stations, pharmacies, and boutiques for antibacterial activity toward prototypical Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial pathogens. Results revealed substantial variability in the efficacy of many sanitizers evaluated. Formulations following World Health Organization-recommended ingredients (80% ethanol or 75% isopropyl alcohol) or those including benzalkonium chloride as the active principal ingredient displayed excellent antibacterial activity, whereas others exhibited modest or poor activity in the assays performed. Results also revealed that E. coli was generally more susceptible to most sanitizers in comparison to S. aureus and that there was significant strain-to-strain variability in hand sanitizer antimicrobial efficacy regardless of the organism evaluated. Further, tests of a subset of hand sanitizers toward severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) revealed no direct correlation between antibacterial and antiviral performance, with all ethyl alcohol formulations performing equally well and displaying improved activity in comparison to benzalkonium chloride-containing sanitizer. Taken together, these results indicate that there is likely to be substantial variability in the antimicrobial performance of commercially available hand sanitizers, particularly toward bacterial pathogens, and a need to evaluate the efficacy of sanitizers under development. IMPORTANCE In response to the coronavirus disease 2019 (COVID-19) pandemic, hand hygiene has taken on a prominent role in efforts to mitigate SARS-CoV-2 transmission and infection, which has led to a radical increase in the number and types of hand sanitizers manufactured to meet public demand. To our knowledge, no studies have evaluated or compared the antimicrobial performance of hand sanitizers that are being produced under COVID-19 emergency authorization. Tests of 46 commercially available hand sanitizers purchased from national chain brick-and-mortar stores revealed considerable variability in their antibacterial performance toward two bacterial pathogens of immediate health care concern, S. aureus and E. coli. Expanded testing of a subset of hand sanitizers revealed no direct correlation between antibacterial performance of individual sanitizers and their activity toward SARS-CoV-2. These results indicate that as the pandemic subsides, there will be a need to validate the antimicrobial efficacy of sanitizers being produced.

scholarly journals Enhanced Photocatalytic and Antibacterial Performance of ZnO Nanoparticles Prepared by an Efficient Thermolysis Method

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 608 ◽  
Author(s):  
Md. Hanif ◽  
Insup Lee ◽  
Jeasmin Akter ◽  
Md. Islam ◽  
Ali Zahid ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Zno Nanoparticles ◽  
Zinc Acetate Dihydrate ◽  
Hexagonal Wurtzite Structure ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
E Coli ◽  
Antibacterial Performance ◽  
Short Time

ZnO nanoparticles (ZnO-NPs) were synthesized by a straightforward modified thermal method using only one chemical: zinc acetate dihydrate. The process is environmentally safer than other methods because it does not involve other chemicals or a catalyst, acid, or base source. X-ray diffraction analysis indicated that the ZnO-NPs crystallize in the hexagonal wurtzite structure. The UV–vis absorption spectra revealed a marked redshift, which is critical for enhanced photocatalytic activity. We used methylene blue for photocatalytic activity tests and found an excellent degradation percentage (99.7%) within a short time (80 min). The antibacterial activity of the synthesized ZnO-NPs was tested against Escherichia coli at different concentrations of ZnO-NPs. The analysis revealed that the minimum inhibitory concentration (MIC) of the ZnO-NPs against E. coli was 30–50 μg/mL. Our ZnO-NPs were found to be more effective than previously reported ZnO-NPs synthesized via other methods.

scholarly journals Hydrothermal Fabrication of Spindle-Shaped ZnO/Palygorskite Nanocomposites Using Nonionic Surfactant for Enhancement of Antibacterial Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1453 ◽  
Author(s):  
Aiping Hui ◽  
Shuqing Dong ◽  
Yuru Kang ◽  
Yanmin Zhou ◽  
Aiqin Wang
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Low Cost ◽  
Ionic Surfactants ◽  
E Coli ◽  
Antibacterial Performance ◽  
Good Antibacterial Activity ◽  
Controllable Growth ◽  
And Staphylococcus Aureus

In order to improve the antibacterial performance of natural palygorskite, spindle-like ZnO/palygorskite (ZnO/PAL) nanocomposites with controllable growth of ZnO on the surface of PAL were prepared in the presence of non-ionic surfactants using an easy-to-operate hydrothermal method. The obtained ZnO/PAL nanocomposites have a novel and special spindle-shaped structure and good antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and are also low cost. The minimum inhibitory concentrations of ZnO/PAL nanocomposites toward E. coli and S. aureus reached 1.5 and 5 mg/mL, respectively.

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