The role of horizontal gene transfer in the evolution of selected foodborne bacterial pathogens.

Bacteria use various ways to transfer genetic information. These methods include: conjugation, which requires cell to cell contact between cells, transduction, which is bacteriophage-facilitated transfer of genetic information, and transformation, which is the uptake of free DNA from the environment. Usually the genes to be transferred lie on mobile genetic elements, pieces of DNA that encode proteins important to facilitate movement of DNA within or between genomes. This review highlights the transfer methods and the role of the assorted mobile genetic elements in the evolution of four foodborne bacterial pathogens: Escherichia coli O157:H7, Salmonella, Staphylococcus aureus and Listeria monocytogenes.