Research article

Population structure of Helicobacter pylori among ethnic groups in Malaysia: recent acquisition of the bacterium by the Malay population

Chin Yen Tay¹ , Hazel Mitchell¹ , Quanjiang Dong¹ , Khean-Lee Goh² , Ian W Dawes¹ and Ruiting Lan¹

¹School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia

²Department of Medicine, Faculty of Medicine, University of Malaysia, Kuala Lumpar, Malaysia

author email corresponding author email

BMC Microbiology 2009, 9:126doi:10.1186/1471-2180-9-126

Published:	19 June 2009

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.

Conclusion

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.