Genetic differences among related microbes dictate many observed biochemical and virulence differences. For example, some strains of the bacterium Escherichia coli are harmless members of the normal m...Genetic differences among related microbes dictate many observed biochemical and virulence differences. For example, some strains of the bacterium Escherichia coli are harmless members of the normal microbiota in the human gastrointestinal tract. Other strains of the same species have genes that give them the ability to cause disease. In bacteria, such genes are not inherited via sexual reproduction, as in humans.
