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World J Gastroenterol. May 21, 2014; 20(19): 5666-5671
Published online May 21, 2014. doi: 10.3748/wjg.v20.i19.5666
Reduced genome size of Helicobacter pylori originating from East Asia
Quan-Jiang Dong, Li-Li Wang, Zi-Bing Tian, Xin-Jun Yu, Sheng-Jiao Jia, Shi-Ying Xuan
Quan-Jiang Dong, Li-Li Wang, Zi-Bing Tian, Xin-Jun Yu, Sheng-Jiao Jia, Shi-Ying Xuan, Central Laboratories and Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao 266000, Shandong Province, China
Zi-Bing Tian, Department of Gastroenterology, the Affiliated Hospital of Qingdao University, Qingdao 266000, Shandong Province, China
Author contributions: Dong QJ and Xuan SY designed the research; Dong QJ and Wang LL drafted the article; Yu XJ and Jia SJ analyzed data; Tian ZB revised the article; and Xuan SY approved the final version.
Correspondence to: Shi-Ying Xuan, MD, PhD, Central Laboratories and Department of Gastroenterology, Qingdao Municipal Hospital, Shinan District, Zhuhai Rd 18, Qingdao 266000, Shandong Province, China. jiangacer@126.com
Telephone: +86-532-88905289 Fax: +86-532-85968434
Received: September 28, 2013
Revised: November 19, 2013
Accepted: January 6, 2014
Published online: May 21, 2014
Processing time: 231 Days and 18.9 Hours
Abstract

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.

Keywords: Helicobacter pylori; Genome; Mutation; Epidemiology; Recombination

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.