The antimicrobial activity of Silver Nanoparticles Antimicrobial against E. coli was investigated as a model for Gram-negative bacteria. Bacteriological tests were performed in Luria–Bertani (LB) medium on solid agar plates and in liquid systems supplemented with different concentrations of nanosized silver particles. These particles were shown to be an effective bactericide. Scanning and transmission electron microscopy (SEM and TEM) were used to study the biocidal action of this nanoscale material. The results confirmed that the treated E. coli cells were damaged, showing formation of “pits” in the cell wall of the bacteria, while the silver nanoparticles were found to accumulate in the bacterial membrane. A membrane with such a morphology exhibits a significant increase in permeability, resulting in death of the cell. These nontoxic nanomaterials, which can be prepared in a simple and cost-effective manner, may be suitable for the formulation of new types of bactericidal materials.
There are some bacteria that are not effectively killed by the conventional antibiotics including many strains of gram-negative bacteria. However the innovative world of science and the need of developing an effective way to cope with this situation has lead scientist to manage a new technology in this regard.
Rani Pattabi and her colleagues at Mangalore University, explains in the international journal of nanoparticles that an electron beam when blasted on a silver nitrate solution can generate nanoparticles.
These particles are shown to be effective against gram-negative species that are not affected by conventional antibacterial agents.
The researchers in India also pointed that these silver nanoparticles are effective against gram-positive bacteria, such as resistant strains of Staphylococcus aureus and Streptococcus pneumoniae and also effective for treating gram-negative Escherichia coli and Pseudomonas aeruginosa.The problem that is threatening human health is resistance to the existing conventional antibiotics. Therefore the chemists all around the world are desperately trying to develop newer compounds that can easily be bactericidal for strains such as MRSA (methicillin or multiple-resistant Staphylococcus aureus) and E. coli O157.
Since the ancient times, silver has been renowned for its bactericidal activities.
Therefore a technological advancement in the use of silver means a major step forward and a promise for a wide range of applications of silver as anti bacterial agent in the times where antibiotic resistance is proving to be an obstacle for anti bacterial use. Thus the emergence of silver nanoparticles and other such bacteriostatic agents have become a new industrial revolution.
The experimentation involving the radiations to split the silver compounds to release silver ions that will clump together and form nanoparticles, have been taken as a challenge by the researchers. The target was in fact to get a new approach that avoids the need for costly and hazardous reducing agents and that these can be used to get particles of a controlled size that controls its properties as well.
So Pattabi and colleagues used electron beam technology to irradiate silver nitrate solutions in a biocompatible polymer that was polyvinyl alcohol, to form silver nanoparticles.
The Preliminary tests have shown that silver nanoparticles produced by this straightforward, non-toxic method are indeed highly active against S. aureus, E. coli, and P. aeruginosa.
Now we can imagine that our shoes, socks or even the keyboard we are using may be impregnated with silver nanoparticles that can kill some bacteria and might as well prevent the spread of infection among computer users.
These can be the frontline defenses such as these environmentally benign and cost-effective antibacterial compounds and these can prevent spreading the infections through contact with computer keyboard, phones and other devices.
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