Spanish physicists have managed to break through the cell wall of Escherichia coli with a needle atomic force microscope. To break it took power more than 20 nanonewtons, which exceeds previous estimates. In addition, it was found that for the cessation of cell division wand sufficiently weak pressure. In an article published in the journal ACS Applied Materials & Interfaces, to achieve such mechanical and bactericidal effect, scientists suggest the use of elongated colloidal nanoparticles in solution.
In recent years, bacteria with greater speed to adapt to traditional chemical antibiotics, after which the latter stops working (in detail about the problems of modern antibiotics and multi-resistant bacteria we wrote in a material “the End of a great era”). The only thing the bacteria can’t defend is a mechanical rupture of the cell membrane. Scientists found such an effect in nature (for example, on the wing of a dragonfly) and have already started to create the mechanical and antibacterial nanostructures in the form of colloidal nanoparticles or surfaces with rods of titanium or carbon materials.
The mechanism of such destruction of the cell wall is not fully understood, although scientists have been watching him through an atomic force microscope and tried to model. So, physics is already pierced by the tip of an atomic force microscope the cell wall of gram-negative bacteria Salmonella typhimurium — to a rupture force was necessary in one or two nanonewton. However, scientists noticed that the cell was still alive after several punctures through the reorganization of phospholipids in the cell membrane. Also the tip of an atomic force microscope was simulated the interaction of bacteria and single-wall carbon nanotubes. For dried cells of Escherichia coli
and Bacillus subtilis force for breaking of cell walls exceeded ten nanonewtons, which is to provide one contact of the nanotube with the bacterium, but, for example, it is possible to achieve in the filtering process through a nanotube membrane.
To install the necessary strength for piercing Escherichia coli, Spanish physics from the Autonomous University of Madrid under the leadership of Cristina Flors (Cristina Flors), push on the immobilized cells with a needle atomic force microscope. For the viability of the cells was observed using fluorescence propidium iodide, which after binding with DNA and RNA increases its luminosity.