Geographic distribution of methyltransferases of Helicobacter pylori: evidence of human host population isolation and migration

• Published in: BMC microbiology 2009-09, Vol.9 (1), p.193-193, Article 193
• Main Authors: Vale, Filipa F, Mégraud, Francis, Vítor, Jorge M B
• Format: Article
• Language: English
• Subjects: Bacteria; Distribution; DNA methylation; DNA, Bacterial; DNA, Bacterial - genetics; Emigration and Immigration; Gastric cancer; Gastritis; Gastrointestinal diseases; Genes; Genes, Bacterial; Genetics, Population; Genome, Bacterial; Genomes; Geographical distribution; Geography; Helicobacter Infections; Helicobacter Infections - microbiology; Helicobacter pylori; Helicobacter pylori - genetics; Humans; Life Sciences; Logistic Models; Logistics; Methyltransferase; Methyltransferases; Methyltransferases - genetics; Microbiology and Parasitology; Migration; peptic ulcers; Physiological aspects; Properties; Regression analysis; Research article; RNA polymerase; Sequence Analysis, DNA; Studies
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/1471-2180-9-193

Helicobacter pylori colonizes the human stomach and is associated with gastritis, peptic ulcer, and gastric cancer. This ubiquitous association between H. pylori and humans is thought to be present since the origin of modern humans. The H. pylori genome encodes for an exceptional number of restriction and modifications (R-M) systems. To evaluate if R-M systems are an adequate tool to determine the geographic distribution of H. pylori strains, we typed 221 strains from Africa, America, Asia, and Europe, and evaluated the expression of different 29 methyltransferases. Independence tests and logistic regression models revealed that ten R-M systems correlate with geographical localization. The distribution pattern of these methyltransferases may have been originated by co-divergence of regional H. pylori after its human host migrated out of Africa. The expression of specific methyltransferases in the H. pylori population may also reflect the genetic and cultural background of its human host. Methyltransferases common to all strains, M. HhaI and M. NaeI, are likely conserved in H. pylori, and may have been present in the bacteria genome since the human diaspora out of Africa. This study indicates that some methyltransferases are useful geomarkers, which allow discrimination of bacterial populations, and that can be added to our tools to investigate human migrations.