Escherichia coli Transcriptome or Gene expression

E. coli O157:H7, the most notorious EHEC strain due to its high mortality rate, is thought to have evolved from the less virulent EPEC O55:H7. E. coli O157:H7 perfer colonize large intestine, while EPEC O55:H7 infect small intestine for infection. The close relationship between this pair of bacteria makes them suitable for use in comparative studies of the differences in EHEC and EPEC virulence. Genomic comparisons have revealed that genetic determinants acquired during the evolutionary process contribute to the higher virulence of O157:H7, especially Shiga toxin-converting phages and a large virulence plasmid (pO157). However, these analyses provided no hints concerning the molecular basis of the different colonization sites of the bacteria.To investigate possible mechanisms underlying the different virulence features of EHEC and EPEC, we compared the gene expression profiles of E. coli O157:H7 EDL933 and E. coli O55:H7 CB9615 after 3 h of incubation with HeLa cells using the RNA-Seq technique.