Saving grace

An international team of scientists has sequenced the entire DNA sequence of the bacterium that causes the deadly legionnaires' disease. The Legionella pneumophila bacterium infects macrophages in lung tissue. These are cells that engulf and destroy foreign material.

L pneumophila switches off the internal 'waste disposal system' that macrophages use for destroying any nasty bugs. "The way the bacteria subverts this defence mechanism could be one of the targets for treatments. With the sequencing, scientists could also find ways to prevent some of the interactions between the host cell and the molecules in the bacteria," the scientists assert.

The sequencing has already highlighted genes that may account for L pneumophila's resistance to disinfectants and drugs.