Escherichia coli (E. coli) strains are normal flora of human gastrointestinal tract. The evolution encoded by horizontally-transferred genetic (HGT) elements has been perceived in several species. E. coli strains have acquired virulence potential factors by attainment of particular loci through HGT, transposons or phages. The heterogeneous nature of these strains is because of HGT through mobile genetic elements. These genetic exchanges that occur in bacteria provide the genetic diversity.
Part of the book: Escherichia coli