title: Reduced genome size of Helicobacter pylori originating from East Asia.
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.
authors.affiliation: 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.
authors.forename: Quan-Jiang
authors.initials: QJ
authors.lastname: Dong
authors.affiliation: 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.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Wang
authors.affiliation: 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.
authors.forename: Zi-Bing
authors.initials: ZB
authors.lastname: Tian
authors.affiliation: 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.
authors.forename: Xin-Jun
authors.initials: XJ
authors.lastname: Yu
authors.affiliation: 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.
authors.forename: Sheng-Jiao
authors.initials: SJ
authors.lastname: Jia
authors.affiliation: 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.
authors.forename: Shi-Ying
authors.initials: SY
authors.lastname: Xuan
mesh_terms: D001208:Asia; D014644:Genetic Variation; D059646:Genome Size; D016680:Genome, Bacterial; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D009154:Mutation; D010802:Phylogeny; D015995:Prevalence; D011995:Recombination, Genetic; D013270:Stomach / Q000382:microbiology
keywords: Epidemiology; Genome; Helicobacter pylori; Mutation; Recombination