Published online May 21, 2014. doi: 10.3748/wjg.v20.i19.5666
Revised: November 19, 2013
Accepted: January 6, 2014
Published online: May 21, 2014
Helicobacter pylori (H. pylori), a major pathogen colonizing the human stomach, shows great genetic variation. Comparative analysis of strains from different H. pylori populations revealed that the genome size of strains from East Asia decreased to 1.60 Mbp, which is significantly smaller than that from Europe or Africa. In parallel with the genome reduction, the number of protein coding genes was decreased, and the guanine-cytosine content was lowered to 38.9%. Elimination of non-essential genes by mutations is likely to be a major cause of the genome reduction. Bacteria with a small genome cost less energy. Thus, H. pylori strains from East Asia may have proliferation and growth advantages over those from Western countries. This could result in enhanced capacity of bacterial spreading. Therefore, the reduced genome size potentially contributes to the high prevalence of H. pylori in East Asia.
Core tip: Comparative analysis of strains from different Helicobacter pylori (H. pylori) populations revealed that the genome size of strains from East Asia was reduced. In parallel with this, the number of protein coding genes and the guanine-cytosine content were decreased. The reduced genome of H. pylori from East Asia potentially contributes to the high prevalence of H. pylori in East Asia.