Comparative study between Helicobacter pylori and host human genetics in the Dominican Republic

BackgroundHelicobacter pylori, a bacterium that infects the human stomach, has high genetic diversity. Because its evolution is parallel to human,H. pyloriis used as a tool to trace human migration. However, there are few studies about the relationship between phylogeography ofH. pyloriand its host human.MethodsWe examined bothH. pyloriDNA and the host mitochondrial DNA and Y-chromosome DNA obtained from a total 119 patients in the Dominican Republic, where human demography consists of various ancestries. DNA extracted from culturedH. pyloriwere analyzed by multi locus sequence typing. Mitochondrial DNA and Y-chromosome DNA were evaluated by haplogroup analyses.ResultsH. pyloristrains were divided into 2 populations; 68 strains with African group (hpAfrica1) and 51 strains with European group (hpEurope). In Y-chromosomal haplogroup, European origin was dominant, whereas African origin was dominant both inH. pyloriand in mtDNA haplogroup. These results supported the hypothesis that mother-to-child infection is predominant inH. pyloriinfection. The Amerindian type of mtDNA haplogroup was observed in 11.8% of the patients; however, Amerindian type (hspAmerind) ofH. pyloriwas not observed. Although subpopulation type of most hpAfrica1 strains in Central America and South America were hybrid (hspWAfrica/hpEurope), most Dominican Republic hpAfrica1 strains were similar to those of African continent.ConclusionsGenetic features ofH. pylori, mtDNA, and Y haplogroups reflect the history of colonial migration and slave trade in the Dominican Republic. Discrepancy betweenH. pyloriand the host human genotypes support the hypothesis that adaptability of hspAmerindH. pyloristrains are weaker than hpEurope strains.H. pyloristrains in the Dominican Republic seem to contain larger proportion of African ancestry compared to other American continent strains.