LONDON, August 31 (SPIS MedWire). The genome of Pseudomonas aeruginosa has been mapped - the largest bacterium sequenced so far. It can be found in soil and household plumbing, and is resistant to disinfectants and antibiotics - enabling it to infect people with compromised immune systems. Sufferers of cystic fibrosis are particularly at risk, with P. aeruginosa infection being the main cause of fatal lung damage amongst this group. The genome was mapped by researchers at the University of Washington Genome Center and the PathoGenesis Corporation, in the hope of identifying new drug targets. Professor Maynard V Olson, Director of the Genome Center, explained, "We will now take the gene sequencing data and attempt to define the molecular mechanisms of infection for P. aeruginosa. We want to see which genes are needed for survival in its human host and which are needed for drug resistance." The primary findings suggest that a large number of genes make up the complex genome that enables the bacterium to adapt and survive in many different environments. In addition, the bacterium's ability to withstand antibiotics in its human host could be due to the genome encoding a number of pumps that are able to expel antibiotics faster than they can accumulate.