scholarly journals Relationship between mechano-bactericidal activity and nanoblades density on chemically strengthened glass

2021 ◽  
Vol 11 (1) ◽  
pp. 138-146
Author(s):  
Yuan Xie ◽  
Yuanhua He ◽  
Xiantao Chen ◽  
Daqin Bu ◽  
Xiaolong He ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Civil Aviation ◽  
Ultrasonic Cleaning ◽  
Strengthened Glass ◽  
Alkaline Etching ◽  
Bactericidal Mechanism ◽  
Etching Method ◽  
Bactericidal Properties ◽  
New Generation

Abstract Establishing the correlation between the topography and the bactericidal performance is the key to improve the mechano-bactericidal activity. However, due to the complexity of the mechano-bactericidal mechanism, the correlation between density and bactericidal performance is still not clear. Based on this, a series of nanoblades (NBs) with various density but similar thickness and height were prepared on the chemically strengthened glass (CSG) substrate by a simple alkaline etching method. The mechano-bactericidal properties of NBs on CSG (NBs@CSG) surfaces exposed to Escherichia coli were evaluated. The results show that with the NB density increasing, the mechano-bactericidal performance of the surface increased first and then decreased. Besides, the bactericidal performance of NBs@CSG is not affected after four consecutive ultrasonic cleaning bactericidal experiments. This article can provide guidance for the design of the new generation of mechano-bactericidal surfaces. In addition, this technology is expected to be applied to the civil aviation cabin window lining.

scholarly journals Antibacterial and Antimembrane Activities of Cecropin A in Escherichia coli

2000 ◽  
Vol 44 (3) ◽  
pp. 602-607 ◽  
Author(s):  
Loraine Silvestro ◽  
Jeffrey N. Weiser ◽  
Paul H. Axelsen
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Membrane Permeabilization ◽  
Lipid Vesicle ◽  
Cecropin A ◽  
Vesicle Membranes ◽  
Bactericidal Mechanism ◽  
Concentration Dependences

ABSTRACT The ability of cecropin A to permeabilize and depolarize the membranes of Escherichia coli ML-35p bacteria has been compared to its bactericidal activity in an extension of earlier studies performed on synthetic lipid vesicle membranes (L. Silvestro, K. Gupta, J. H. Weiser, and P. H. Axelsen, Biochemistry 36:11452–11460, 1997). Our results indicate that differences in the concentration dependences of membrane permeabilization and depolarization seen in synthetic vesicles are not manifested in whole bacteria. The concentration dependences of both phenomena roughly correlate with bactericidal activity, suggesting that the bactericidal mechanism of cecropin A is related to membrane permeabilization.

Bactericidal activity of drugs from Juglans Regia to the microflora of livestock premises in organic pig breeding

2020 ◽  
pp. 113-122
Author(s):  
Serhii Zinoviev ◽  
Andrii Kurman ◽  
Dmytro Bindiug ◽  
Pavlo Grubich ◽  
Liubov Lepeta
Keyword(s):  
Bactericidal Activity ◽  
Juglans Regia ◽  
Herbal Remedies ◽  
Potential Efficacy ◽  
Internal Structures ◽  
Bactericidal Properties ◽  
Experimental Base ◽  
Quality Of Products ◽  
Gram Positive Cocci

The introduction of the newest technologies of organic pig breeding has the basic principle of minimizing the use in pigs of chemicals, trace amounts of which in pig production adversely affect the quality of products and the health of consumers. The transition to herbal remedies, the maximum possible rejection of chemical synthesis products, is inhibited, in the main, by the relatively small spectrum of plant compounds with the investigated activity. According to the results of previous studies, six working solutions of Juglans regia L phytosupply extracts - potential phytosine disinfectants were developed: To investigate the bactericidal activity of the experimental preparations of Juglans regia, flushes were made from the internal structures and technological equipment of the housing of the pig stock of the experimental base v. Takhtaulove. Obtained samples of typical banal microflora of the pig complex were mixed to obtain a bacterial-containing suspension averaged over the concentration of microbial bodies and the spectrum of types of microflora in the microbiota. When cultured on nutrient media, with the superficial sowing of a suspension of banal microflora of a pig in the presence of a potential phytodisinfectant, processes of development of individual colonies of the microflora are observed. The amount and intensity of their development, the degree of inhibition of life, assess the level of bactericidal activity of the extracts. The highest bactericidal and fungicidal activity, and consequently, the potential efficacy as a possible disinfectant in the technology of organic pig breeding was revealed by the extracts of phytosupply Juglans regia L No. 2 (extractant - acetic acid to 5 %, nut of wax ripeness) and 4 (extractant, alcohol 20 % nutrient wax ripeness (proven after obtaining the primary extract of up to 5 % alcohol), which have bactericidal properties against gram-positive cocci and gram-negative sticks, but have a weak effect on the spore-forming bacilli. Key words: organic pig breeding, bactericidal activity, phyto-disinfectant, commonplace typical microflora of a pig complex, phyto row materials, walnut extract.

Effects of Water Source, Dilution, Storage, and Bacterial and Fecal Loads on the Efficacy of Electrolyzed Oxidizing Water for the Control of Escherichia coli O157:H7

2004 ◽  
Vol 67 (7) ◽  
pp. 1377-1383 ◽  
Author(s):  
S. M. L. STEVENSON ◽  
S. R. COOK ◽  
S. J. BACH ◽  
T. A. McALLISTER
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Storage Temperature ◽  
Uv Light ◽  
Tap Water ◽  
Organic Matter Content ◽  
Water Source ◽  
Deionized Water ◽  
Escherichia Coli O157 ◽  
E Coli

To evaluate the potential of using electrolyzed oxidizing (EO) water for controlling Escherichia coli O157:H7 in water for livestock, the effects of water source, electrolyte concentration, dilution, storage conditions, and bacterial or fecal load on the oxidative reduction potential (ORP) and bactericidal activity of EO water were investigated. Anode and combined (7:3 anode:cathode, vol/vol) EO waters reduced the pH and increased the ORP of deionized water, whereas cathode EO water increased pH and lowered ORP. Minimum concentrations (vol/vol) of anode and combined EO waters required to kill 104 CFU/ml planktonic suspensions of E. coli O157:H7 strain H4420 were 0.5 and 2.0%, respectively. Cathode EO water did not inhibit H4420 at concentrations up to 16% (vol/vol). Higher concentrations of anode or combined EO water were required to elevate the ORP of irrigation or chlorinated tap water compared with that of deionized water. Addition of feces to EO water products (0.5% anode or 2.0% combined, vol/vol) significantly reduced (P < 0.001) their ORP values to <700 mV in all water types. A relationship between ORP and bactericidal activity of EO water was observed. The dilute EO waters retained the capacity to eliminate a 104 CFU/ml inoculation of E. coli O157:H7 H4420 for at least 70 h regardless of exposure to UV light or storage temperature (4 versus 24°C). At 95 h and beyond, UV exposure reduced ORP, significantly more so (P < 0.05) in open than in closed containers. Bactericidal activity of EO products (anode or combined) was lost in samples in which ORP value had fallen to ≤848 mV. When stored in the dark, the diluted EO waters retained an ORP of >848 mV and bactericidal efficacy for at least 125 h; with refrigeration (4°C), these conditions were retained for at least 180 h. Results suggest that EO water may be an effective means by which to control E. coli O157:H7 in livestock water with low organic matter content.

Alteration of the phagocytosis and antimicrobial defense of Octodonta nipae (Coleoptera: Chrysomelidae) pupae to Escherichia coli following parasitism by Tetrastichus brontispae (Hymenoptera: Eulophidae)

2018 ◽  
Vol 109 (2) ◽  
pp. 248-256
Author(s):  
E. Meng ◽  
J. Li ◽  
B. Tang ◽  
Y. Hu ◽  
T. Qiao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Immune Responses ◽  
Mrna Expression ◽  
Bactericidal Activity ◽  
Bacterial Infections ◽  
Expression Level ◽  
Primary Immune Response ◽  
Mrna Expression Level ◽  
E Coli

AbstractAlthough parasites and microbial pathogens are both detrimental to insects, little information is currently available on the mechanism involved in how parasitized hosts balance their immune responses to defend against microbial infections. We addressed this in the present study by comparing the immune response between unparasitized and parasitized pupae of the chrysomelid beetle, Octodonta nipae (Maulik), to Escherichia coli invasion. In an in vivo survival assay, a markedly reduced number of E. coli colony-forming units per microliter was detected in parasitized pupae at 12 and 24 h post-parasitism, together with decreased phagocytosis and enhanced bactericidal activity at 12 h post-parasitism. The effects that parasitism had on the mRNA expression level of selected antimicrobial peptides (AMPs) of O. nipae pupae showed that nearly all transcripts of AMPs examined were highly upregulated during the early and late parasitism stages except defensin 2B, whose mRNA expression level was downregulated at 24 h post-parasitism. Further elucidation on the main maternal fluids responsible for alteration of the primary immune response against E. coli showed that ovarian fluid increased phagocytosis at 48 h post-injection. These results indicated that the enhanced degradation of E. coli in parasitized pupae resulted mainly from the elevated bactericidal activity without observing the increased transcripts of target AMPs. This study contributes to a better understanding of the mechanisms involved in the immune responses of a parasitized host to bacterial infections.

Photocatalytic Bactericidal Mechanism of Nanoscale TiO2 Films on Escherichia coli

2011 ◽  
Vol 11 (9) ◽  
pp. 7621-7626 ◽  
Author(s):  
Danmei Pan ◽  
Zhibing Zhan ◽  
Dagui Chen ◽  
Zhicheng Wu ◽  
Aiying Pang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Mechanism

scholarly journals 1D TiO2 Nanostructures Prepared from Seeds Presenting Tailored TiO2 Crystalline Phases and Their Photocatalytic Activity for Escherichia coli in Water

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Julieta Cabrera ◽  
Dwight Acosta ◽  
Alcides López ◽  
Roberto J. Candal ◽  
Claudia Marchi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Photocatalytic Activity ◽  
Bactericidal Activity ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
E Coli ◽  
1D Nanostructures ◽  
Sol Gel Synthesis ◽  
Hydrolysis Of ◽  
Tio2 Nanostructures

TiO2 nanotubes were synthesized by alkaline hydrothermal treatment of TiO2 nanoparticles with a controlled proportion of anatase and rutile. Tailoring of TiO2 phases was achieved by adjusting the pH and type of acid used in the hydrolysis of titanium isopropoxide (first step in the sol-gel synthesis). The anatase proportion in the precursor nanoparticles was in the 3–100% range. Tube-like nanostructures were obtained with an anatase percentage of 18 or higher while flake-like shapes were obtained when rutile was dominant in the seed. After annealing at 400°C for 2 h, a fraction of nanotubes was conserved in all the samples but, depending on the anatase/rutile ratio in the starting material, spherical and rod-shaped structures were also observed. The photocatalytic activity of 1D nanostructures was evaluated by measuring the deactivation of E. coli in stirred water in the dark and under UV-A/B irradiation. Results show that in addition to the bactericidal activity of TiO2 under UV-A illumination, under dark conditions, the decrease in bacteria viability is ascribed to mechanical stress due to stirring.

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