CHAPTER 2 – Evolutionary aspects of toxin-producing bacteria

摘要: This chapter outlines the evolutionary aspect of toxins, specially ones produced by certain bacterias. Increasing evidence indicates that evolution toxin genes involves horizontal gene transfer and recombination events mediated through plasmids, phages, transposons, other yet-undefined transmissible elements. In addition to host environment, transmission also can occur outside human animal host, including in soil aquatic environments, phyllosphere, guts insects, parasites, vectors. The bacterial toxins HGT exposure a combination both external environments. New suggests acquisition large DNA segments (HGT) may account for much more rapid pathogens, particularly terms origin virulence factors such as than was previously thought. Most are located on pathogenicity islands (PAIs) plasmids or chromosome prophages Possible mechanisms which contributes pathogenesis include exchange among different populations; one-step toxin(s) increase survival against host's immune system provide means dissemination within between hosts; provision enhance environment when body.