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Lab Research
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The Effect of a Silver-Containing Hydrofiberª Dressing on Bacterial Ultrastructure First Author: Mike Walker Authors: Mike Walker, Jan Hobot, Phil Bowler Transmission electron microscopy has been used to show how bacterial ultrastructure is affected when bacteria are immobilised within a silver-containing Hydrofiberª wound dressing. Liquid cultures, with and without silver, were prepared as controls (i.e. with water and silver nitrate). Bacterial cells were processed for electron microscopy to observe in detail the effects of silver on their ultrastructure. Cells were incubated within either a non-antimicrobial Hydrofiberª (AQUACEL¨) or a silver-containing Hydrofiberª (AQUACEL¨ Ag) dressing. Silver ions from the dressing were found to affect the shape of the bacterial nucleoid and to alter the appearance of the bacterial DNA. It is proposed that these changes come about due to silver affecting the permeability of the cytoplasmic membrane. Ions leak out of and into the cell, causing changes to the internal osmotic pressure, which affects nucleoid shape. Loss of ions can affect the appearance of DNA, from a fine fibrillar form to one with thicker fibres. These adverse ultrastructural changes can affect both cell viability and division. |
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