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

Abstract

BackgroundHelicobacter 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.ResultsSeventy 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.ConclusionThe 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.

Antigenic Proteins of Helicobacter pylori of Potential Diagnostic Value

“…hspIndia. It can be expected that if more isolates or more geographical regions are sampled, more subpopulations of H. pylori and populations can be identified (Tay et al, 2009). As mentioned earlier, the diagnostic accuracy of serology kits for detection of H. pylori antibodies may be influenced by strain differences in different regions of the world (Leung et al, 1999;Miwa et al, 2000;Obata et al, 2003).…”

Helicobacter pylori Genetic Diversity and Gastro-duodenal Diseases in Malaysia

“…Analysis of seven housekeeping genes of H. pylori by multi-locus sequence typing (MLST) suggest that the bacteria originated in Africa and later split into seven distinct population groups (hpEurope, hpNEAfrica, hpAfrica1, hpAfrica2, hpAsia2, hpSahul and hpEastAsia) and subpopulations that are strongly associated with geographical localization. As for the subpopulations, AE1 and AE2 are within hpEurope, hspWafrica and hspSAfrica within hpAfrica1, hspIndia within hpAsia2 and hspEAsia, hspAmerind and hspMaori within the population of hpEastAsia678. In Malaysia, H. pylori hpAsia2/hspIndia mainly colonises Indian and Malay subjects while hpEastAsia/hspEAsia predominantly colonises Chinese subjects.…”

“…In Malaysia, H. pylori hpAsia2/hspIndia mainly colonises Indian and Malay subjects while hpEastAsia/hspEAsia predominantly colonises Chinese subjects. These two groups (hpEastAsia/hspEAsia and hpAsia2/hspIndia) accounted for 41.5% and 39.0% of all H. pylori isolates respectively6.…”

Polymorphism in the Helicobacter pylori CagA and VacA toxins and disease

“…10,24,25 Finally, multilocus sequence typing (MLST) of several H. pylori housekeeping genes and the vacA virulence gene has been utilized to develop a classification system that takes advantage of the broader genetic diversity of H. pylori as a means to study its ancestry; 9,12,13,26 MLST identified seven distinct H. pylori populations, some of which have several sub-populations that are named based upon the geographic location in which the strains are found (Table 1). 9,13,14,[26][27][28] This new classification system delineates strains from the classical East Asian, Western, Amerindian or J-Western strain designations, which are based solely on cagA C-terminal polymorphisms.…”