Association Between Horizontal Gene Transfer and Adaptation of Gastric Human Pathogen Helicobacter pylori to the Host

Abstract

Helicobacter pylori exhibit remarkable survival even in the vulnerable environments such as acidic, peristalsis, phagocytosis and oxidative stress. These stresses on the pathogen in the host induce damage of DNA in the pathogen. H. pylori acquired the ability to survive DNA damage by transformation-mediated recombination DNA repair. This repair mechanism helps the pathogen in successfully infecting the host. While many pathogens are competent for transformation only in certain environmental conditions such as starvation, H. pylori is competent throughout the growth. H. pylori may acquire the genetic material from the surrounding environment and contribute to evolution and genetic diversity. The mechanism in acquiring genetic material is ‘horizontal gene transfer’, the major contributing factor in the development of bacterial diversity. Horizontal gene transfer may help the pathogen H. pylori in acquiring antigenic determinants, genes of antibiotic resistance and virulence factors from other organisms to alter and influence pathogenicity. In this chapter, we review and discuss the association between horizontal gene transfer and adaptation of gastric human pathogen H. pylori to the host.