%0 Journal Article
%T Geographic distribution of methyltransferases of Helicobacter pylori: evidence of human host population isolation and migration
%A Filipa F Vale
%A Francis M¨¦graud
%A Jorge MB V¨ªtor
%J BMC Microbiology
%D 2009
%I BioMed Central
%R 10.1186/1471-2180-9-193
%X 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.Helicobacter pylori colonizes about half of the human population and is associated with several gastrointestinal diseases, such as gastritis, peptic ulcer, and gastric cancer [1,2]. The similar pattern of human and H. pylori geographic diversity and distribution suggests a co-evolution between bacteria and man, which can be used to understand human migrations [2]. The H. pylori distribution pattern follows the human migration roots, which suggests that the colonization of the human stomach occurred before modern man left East Africa [2-5].Several H. pylori gene alleles present different prevalence rates among the world H. pylori population. This is the case for vacA that presents allelic diversity of the s-, m- and i-region [6,7]. The cagA gene DNA motifs also presents a clear geographic association, and five types of deletion, insertion, and substitution motifs were found at the 3' end of the H. pylori cag pathogenicity island associated with different human populations [8]. Another study confirms that the candidate virulence factors, vacA, cagA and iceA, cluster according to geographic region [9]. Interestingly, iceA has two known alleles, iceA1 and iceA2 [10,11], with t
%U http://www.biomedcentral.com/1471-2180/9/193