Comprehensive Genome Sequencing of Pathogenic Escherichia Coli and Shigella

Goals

The complete genomes of four well-defined E. coli / Shigella strains are being sequenced to closure, in addition to eight genomes at draft coverage, totaling 12 genomes. This work significantly expands and complements the E. coli / Shigella genome projects that are completed or underway worldwide. The number of diseases that the members of these genera can cause underscores their diversity. We are addressing the breadth of this diversity by focusing our sequencing efforts on representative members of three previously under-sequenced groups: enterotoxigenic E. coli (ETEC), enteroinvasive E. coli(EIEC) and Shigella boydii, all of which cause significant morbidity and mortality in humans. In addition to these pathogenic isolates, we are sequencing E. coli HS, a strain known to colonize the human gastrointestinal tract without causing disease. This commensal genome sequence will provide a genomic scaffold which will facilitate rapid identification and focused analysis of pathogen-specific genomic islands and allow identification of those factors responsible for colonization which are shared among the pathogenic members of the E. coli / Shigella. This work will increase our understanding of these genera, enabling the development of robust typing schema and identification of new vaccine targets, as well as potentially aid in forensic analysis in cases of bioterrorism.

Isolate Selection

Strain selection was performed after extensive consultation with the E. coli / Shigella scientific community, other agencies funding similar projects. A meeting of an Advisory Committee (see list below) resulted in the selection of the twelve E. coli / Shigella strains targeted for genomic sequencing.