MYSTERIOUS DNA

Biology's big brainteaser: are archaea cause for hope or concern?

Unravelling what role, if any, archaea play in disease is becoming a priority for teams of microbiologists around the world. Most believe it's a matter of time before they are confirmed, at least, as contributing to the progress of certain illnesses.
'It's very important we get to the bottom of this, because if archaea are causing diseases we may have a problem,' says Peter Westerman, an expert in archaea at the Technical University of Denmark. The antibiotics we have now have all been designed with bacteria in mind, and a new generation of drugs would be needed to tackle archaea. 'It's all a bit scary,' he says.

The microbiologist Carl Woese divided all life into three groups: bacteria, archaea, and eukaryotes. The latter includes animals, plants and fungi. Archaea are somewhere in the middle but have genetic mechanisms closer to ours than bacteria.
They are tiny single-cell organisms. They make up about a fifth of all life on the planet and cover the whole spectrum of earth's environments.
It had been thought that archaea held the key to switching off pathogenic microbes, but there is increasing speculatiohn that the life-forms are not as benign as once thought.
"On the evidence we've got so far, we should be finding more than 30 types of archaea that cause disease," says Rick Cavicchioli, a molecular biologist at the University of New South Wales.

[Did you know: A gram of human faeces can hold 10 billion archaea.]