scholarly journals In Situ Surface-Directed Assembly of 2D Metal Nanoplatelets for Drug-Free Treatment of Antibiotic-Resistant Bacteria

2021 ◽  
Author(s):  
Parinaz Fathi ◽  
Ayman Roslend ◽  
Maha Alafeef ◽  
Mandy B. Esch ◽  
Dipanjan Pan
Keyword(s):  
Electron Microscopy ◽  
Cell Division ◽  
Bacterial Cell ◽  
Metal Surfaces ◽  
Copper Chloride ◽  
Antibacterial Properties ◽  
Health Concern ◽  
Copper Surfaces ◽  
One Step ◽  
Drug Free

The development of antibiotic resistance among bacterial strains is a major global public health concern. To address this, drug-free antibacterial approaches are needed. High-touch surfaces in particular can serve as a means for the spread of bacteria and other pathogens from one infected person to another. Copper surfaces have long been known for their antibacterial properties. To further enhance the surface's antibacterial properties, we used a one-step surface modification technique to assemble 2D copper chloride nanoplatelets directly onto copper surfaces such as copper tape, transmission electron microscopy (TEM) grids, electrodes, and granules. The nanoplatelets were formed using copper ions from the copper surfaces, enabling their direct assembly onto these surfaces in a one-step process that does not require separate nanoparticle synthesis. The synthesis of the nanoplatelets was confirmed with TEM, scanning electron microscopy, energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). Antibacterial properties of the surfaces with copper chloride nanoplatelets were demonstrated in multi-drug-resistant (MDR) E. coli. The presence of copper chloride nanoplatelets on the surface led to a marked improvement in antibacterial properties compared to the untreated copper surfaces. Surfaces with copper chloride nanoplatelets affected bacterial cell morphology, prevented bacterial cell division, reduced their viability, damaged bacterial deoxyribonucleic acid (DNA), and altered protein expression. In particular, proteins corresponding to cell division, DNA division, and mediation of copper toxicity were down-regulated. This work presents a robust method to directly assemble copper chloride nanoplatelets onto any copper surface to imbue it with improved antibacterial properties. To demonstrate that our method of particle generation can be used with other metal surfaces, we also demonstrate the synthesis of other metal-derived nanoarchitectures on a variety of metal surfaces.

Application of solid-phase immune electron microscopy to study physical and stability characteristics of enterically transmitted non-a, non-b hepatitis virus

1988 ◽  
Vol 46 ◽  
pp. 80-81
Author(s):  
Charles D. Humphrey ◽  
E. H. Cook ◽  
Karen A. McCaustland ◽  
Daniel W. Bradley
Keyword(s):  
Electron Microscopy ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Etiologic Agent ◽  
World Health ◽  
Health Concern ◽  
Morphological Identification ◽  
Immune Electron Microscopy

Enterically transmitted non-A, non-B hepatitis (ET-NANBH) is a type of hepatitis which is increasingly becoming a significant world health concern. As with hepatitis A virus (HAV), spread is by the fecal-oral mode of transmission. Until recently, the etiologic agent had not been isolated and identified. We have succeeded in the isolation and preliminary characterization of this virus and demonstrating that this agent can cause hepatic disease and seroconversion in experimental primates. Our characterization of this virus was facilitated by immune (IEM) and solid phase immune electron microscopic (SPIEM) methodologies.Many immune electron microscopy methodologies have been used for morphological identification and characterization of viruses. We have previously reported a highly effective solid phase immune electron microscopy procedure which facilitated identification of hepatitis A virus (HAV) in crude cell culture extracts. More recently we have reported utilization of the method for identification of an etiologic agent responsible for (ET-NANBH).

ABOUT SOME PECULIARITIES OF THE PHYSIOLOGICAL HETEROGENEITY OF THE POPULATION OF SCENEDESMUS QUADRICAUDA (TURP.) BREB. IN THE PRESENCE OF LOW CONCENTRATIONS OF METALS

2018 ◽  
pp. 34-43
Author(s):  
V. I. Ipatova ◽  
A. G. Dmitrieva ◽  
О. F. Filenko ◽  
T. V. Drozdenko
Keyword(s):  
Cell Division ◽  
Toxic Effect ◽  
Copper Chloride ◽  
Single Cells ◽  
Physiological State ◽  
Scenedesmus Quadricauda ◽  
Physiological Status ◽  
Lag Phase ◽  
Protective Mechanism ◽  
Low Concentrations

The structure of the laboratory population of green microalgae Scenedesmus quadricauda (Turp.) Breb (=Desmodesmus communis E. Hegew.) was studied at different stages of its growth (lag-phase, log-phase and stationary phase) at low concentrations of copper chloride and silver nitrate by the method microculture, allowing to monitor the state and development of single cells having different physiological status. The response of the culture of S. quadricauda - the change in the number of cells and the fractional composition (the fraction of dividing, «dormant» and dying cells) depended not only on the concentration of the toxicant in the medium, but also on the physiological state of the culture: the level of synchronization and the growth phase. Silver ions at low concentrations had a more pronounced toxic effect on the culture than copper ions at different phases of its development, especially at a concentration of 0.001 mg/l (10-9 M). The main mechanism of the toxic effect of metals is to inhibit the process of cell division. At low concentrations of toxicants, especially at a concentration of 0.001 mg/l, a «paradoxical» effect expressed in the predominance of the fraction of «dormant» cells was revealed. The temporary inhibition of the process of cell division can be regarded as a protective mechanism that allows preserving the integrity of the population and its ability to survive in a changing environment. The obtained data explain the effect of action of low concentrations of substances due to their inclusion in the cell, the subsequent accumulation in the cell and their low excretion.

scholarly journals Cardiolipin-Containing Lipid Membranes Attract the Bacterial Cell Division Protein DivIVA

2021 ◽  
Vol 22 (15) ◽  
pp. 8350
Author(s):  
Naďa Labajová ◽  
Natalia Baranova ◽  
Miroslav Jurásek ◽  
Robert Vácha ◽  
Martin Loose ◽  
...  
Keyword(s):  
Cell Division ◽  
Lipid Bilayers ◽  
Bacterial Cell ◽  
Lipid Membranes ◽  
Model Organism ◽  
Active Role ◽  
Membrane Curvature ◽  
Bacterial Cell Division ◽  
Division Site ◽  
Clostridioides Difficile

DivIVA is a protein initially identified as a spatial regulator of cell division in the model organism Bacillus subtilis, but its homologues are present in many other Gram-positive bacteria, including Clostridia species. Besides its role as topological regulator of the Min system during bacterial cell division, DivIVA is involved in chromosome segregation during sporulation, genetic competence, and cell wall synthesis. DivIVA localizes to regions of high membrane curvature, such as the cell poles and cell division site, where it recruits distinct binding partners. Previously, it was suggested that negative curvature sensing is the main mechanism by which DivIVA binds to these specific regions. Here, we show that Clostridioides difficile DivIVA binds preferably to membranes containing negatively charged phospholipids, especially cardiolipin. Strikingly, we observed that upon binding, DivIVA modifies the lipid distribution and induces changes to lipid bilayers containing cardiolipin. Our observations indicate that DivIVA might play a more complex and so far unknown active role during the formation of the cell division septal membrane.

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