A Comparative Genomic Analysis of Diverse Clonal Types of EnterotoxigenicEscherichia coliReveals Pathovar-Specific Conservation

• DOI: 10.1128/iai.00932-10
• Publication Date: 2010-11-16T05:57:00Z
• Authors: Jason W. Sahl; Hans Steinsland; Julia C. Redman; Samuel V. Angiuoli; James P. Nataro; Halvor Sommerfelt; David A. Rasko
• Keywords: Enterotoxigenic Escherichia coli; Pathovar; Multilocus sequence typing; Genomic island; Comparative Genomics

Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrheal illness in children less than 5 years age low- and middle-income nations, whereas it an emerging enteric pathogen industrialized nations. Despite being important diarrhea, little known about the genomic composition ETEC. To address this, we sequenced genomes five ETEC isolates obtained from Guinea-Bissau with diarrhea. These represent distinct globally dominant clonal groups. Comparative analyses utilizing gene-independent whole-genome alignment method demonstrated that strains share approximately 2.7 million bases sequence. Phylogenetic analysis this "core genome" confirmed diverse history pathovar provides finer resolution E. relationships multilocus sequence typing. No identified regions were conserved exclusively all genomes; however, more content among non-ETEC genomes, suggesting core. Comparisons virulence surface-exposed colonization factor genes across not only variability but also indicated some antigens are restricted to pathovar. Overall, generation these genome sequences, addition two previously generated highlights diversity studies increase our understanding evolution, as well provide insight into factors proteins, which may be targets for vaccine development.