A giant virus that lurks inside amoebas and may cause pneumonia in humans has been spotted by scientists.
“Mimivirus” is the biggest virus found so far, and was discovered in a sample taken from a water cooling tower in Bradford, UK, in 1992.
It has at least 900 genes, an enormous number for a virus, and its size is more like that of a bacterium.
It can be spotted through a good optical microscope – most viruses can only be visualised by electron microscopes.
In terms of DNA, it is approximately a fifth bigger than the virus previously considered to be the largest in the world.