Some types of bacteria are like burglars – they break into cells to feed on the nutrients inside. This tactic may shelter them from the body’s immune system for a while but they don’t stay safe for long because cells have a deadly defence too. They can destroy bacteria with special enzymes in their lysosome, [the cell’s waste disposal unit] and eject the remains, via the outer membrane. Pictured is a human cell (the DNA is stained blue and internal fibres green), which has been invaded by tiny Mycoplasma bacteria (dyed red) in a laboratory experiment. Scientists infected the cells so they could study the ensuing battle with powerful microscopes and map out the cells’ genetic activity as they fought the invaders. Understanding more about the body’s natural defences could help in the development of drugs to fight infection.
Written by Mick Warwicker
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