title: Population structure of Helicobacter pylori among ethnic groups in Malaysia: recent acquisition of the bacterium by the Malay population.
abstract: BACKGROUND
  Helicobacter pylori is a major gastric bacterial pathogen. This pathogen has been shown to follow the routes of human migration by their geographical origin and currently the global H. pylori population has been divided into six ancestral populations, three from Africa, two from Asia and one from Europe. Malaysia is made up of three major ethnic populations, Malay, Chinese and Indian, providing a good population for studying recent H. pylori migration and admixture.
  
  
  RESULTS
  Seventy eight H. pylori isolates, including 27 Chinese, 35 Indian and 16 Malay isolates from Malaysia were analysed by multilocus sequence typing (MLST) of seven housekeeping genes and compared with the global MLST data. STRUCTURE analysis assigned the isolates to previously identified H. pylori ancestral populations, hpEastAsia, hpAsia2 and hpEurope, and revealed a new subpopulation, hspIndia, within hpAsia2. Statistical analysis allowed us to identify population segregation sites that divide the H. pylori populations and the subpopulations. The majority of Malay isolates were found to be grouped together with Indian isolates.
  
  
  CONCLUSIONS
  The majority of the Malay and Indian H. pylori isolates share the same origin while the Malaysian Chinese H. pylori is distinctive. The Malay population, known to have a low infection rate of H. pylori, was likely to be initially H. pylori free and gained the pathogen only recently from cross infection from other populations.
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia. alfred.tay@gmail.com
authors.forename: Chin Yen
authors.initials: CY
authors.lastname: Tay
authors.forename: Hazel
authors.initials: H
authors.lastname: Mitchell
authors.forename: Quanjiang
authors.initials: Q
authors.lastname: Dong
authors.forename: Khean-Lee
authors.initials: KL
authors.lastname: Goh
authors.forename: Ian W
authors.initials: IW
authors.lastname: Dawes
authors.forename: Ruiting
authors.initials: R
authors.lastname: Lan
mesh_terms: D015373:Bacterial Typing Techniques; D019295:Computational Biology; D004269:DNA, Bacterial / Q000235:genetics; D004641:Emigration and Immigration; D005006:Ethnicity; D005798:Genes, Bacterial; D005828:Genetics, Population; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008296:Malaysia / Q000453:epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic
chemical_list: D004269:DNA, Bacterial