patient with a urinary tract infection and the second isolated from an infant with CF, researchers obtained a collection of genes specific to these 2 strains. Analysis of DNA sequences in these clones revealed that the majority of the genes did not share any sequence similarity with any other genes in the Genome Project database. In each case, the percent G+C content was lower than 64% for most of the strain-specific sequences, suggesting that those traits were acquired by horizontal gene transfer. In microevolutional analysis, low-passage DNA sequencing of genomes was used to identify sequences unique to clinical isolates and to compare the genomic variations among them as well as to the Pseudomonas aeruginosa PA01 strain. In addition to generating sequence data that define unique genes in the genomes of these 2 clinical isolates, this approach has been extremely useful in defining regions that are present in the genome of PA01 and absent from the genomes of these 2 clinical strains. These DNA segments define unstable genetic elements that may encode proteins that are potentially deleterious for survival in the host. Lastly, DNA sequences of several loci that accumulate single nucleotide mutations also have been identified. The long-range goal of the genomic comparison project is to correlate the genomic makeup of Pseudomonas aeruginosa strains with specific infections and to monitor the evolution of virulent traits expressed by this pathogen. There is continuous research being done of the mapping of the genome of Pseudomonas aeruginosa, which may lead to potential new treatments for patients with cystic fibrosis. A team of researchers at the University of Washington Genome Center and PathoGenesis Corporation collaborated to complete this genome sequence genetic map. In fact researchers are already using knowledge about the genetic instructions of Pseudomonas to identify targets for novel drug strategies. They will...
