Escherichia coli isolates from infants in Trondheim

The natural history of Escherichia coli strains is still not fully characterized despite being one of the most completely studied organisms. Several fundamental relationships between gene content and ecological function remain to be parsed. We have sequenced twelve commensal and four pathogenic strains isolated from infants in Trondheim and compared several phenotypic characteristics using differential gene content in order to determine enrichment profiles that may explain phenotypic traits. Methodological challenges included compensating for low coverage of the genomes by 454 sequencing. Still, signatures were found that relate to phylogeny, early vs. late colonization, pathogenicity and growth rate characteristics that show comparable enrichments in biological processes but using different genetic elements. Embedded in the sequencing are two pairs of strains that were isolated from the same infant and are essentially the “same” isolate. Genome sequencing has revealed genetic changes that could be attributed to adaption to the host or other microbes.