Methylation has implications in gene expression [66], and H. PSI-7977 mouse pylori associates with several pathologies that may result from different sets of expressed genes [67]. For instance, DNA methylation by M. HpyAIV
was shown to alter transcription of the catalase gene (katA) in H. pylori [68]. Further evidence is needed to understand if the high number Selleck VX-765 and diversity of MTases expressed among H. pylori strains is beneficial for the bacteria and/or plays any role in pathogenicity. Conclusion In conclusion, there is a clear association of some MTases with geographic groups of H. pylori strains, making them useful as geomarkers (Table 2). Indeed, other genes, as cagA or vacA, have allelic forms with particular geographic distributions [6, 8, 69]. Similar results are now observed for the majority strain-specific genes. M. HhaI and M. NaeI are common to all tested strains, which is consistent with the co-evolution theory of man and H. pylori [2, 3] and suggests that their presence in bacterial genome preceded the human diaspora out of Africa. Finally, the association of MTases with geographical bacterial clusters may be observed in other bacterial species, and may reveal to be https://www.selleckchem.com/products/blz945.html good geographic markers to trace bacterial evolution.
Methods H. pylori strains 221 H. pylori strains were isolated from different regions (Africa, America, Asia and Europe) (Table 4). Strains belong to the collections of the Helicobacter and Campylobacter Reference Center of the Portuguese National Institute of Health (INSA), the Helicobacter and Campylobacter National Reference Center (Victor Segalen University, Bordeaux, France) and the Medical Microbiology Institute of Hannover (Germany). Strains belonging to INSA and Helicobacter and Campylobacter National Reference Center were randomly selected, except in cases in which all strains available for each sub-sample group were analysed (strains with African origin). DNA from H. pylori Singapore strains was randomly selected from SSR128129E East Asia
H. pylori strain collection of the Medical Microbiology Institute of Hannover. Except for the country of origin, there is no further information about the ethnic group or ancestry of the human host providing the strain. Due to difficulty in obtaining strains from different geographic origins the number of strains from each continent is uneven. Table 4 Geographic origin of H. pylori strains. Continent Country Number of strains Percentage Europe 146 66.1 Portugal 106 48.0 France 11 5.0 United Kingdom a) 8 3.6 Germany 6 2.7 Sweden 9 4.1 Norway 6 2.7 Africa 38 17.2 Portuguese with African origin b) 20 9.0 Egypt 7 3.2 Burkina Faso 11 5.0 America 27 12.2 USA c) 1 0.5 Costa Rica 6 2.7 Mexico 6 2.7 Argentina 14 6.3 Asia 10 4.5 Singapore 10 4.5 Total 221 100.