Data from: Rapid evolution of distinct Helicobacter pylori subpopulations in the Americas

For the last 500 years, the Americas have been a melting pot both for
genetically diverse humans and for the pathogenic and commensal organisms
associated with them. One such organism is the stomach-dwelling bacterium
Helicobacter pylori, which is highly prevalent in Latin America where it
is a major current public health challenge because of its strong
association with gastric cancer. By analyzing the genome sequence of H.
pylori isolated in North, Central and South America, we found evidence for
admixture between H. pylori of European and African origin throughout the
Americas, without substantial input from pre-Columbian (hspAmerind)
bacteria. In the US, strains of African and European origin have remained
genetically distinct, while in Colombia and Nicaragua, bottlenecks and
rampant genetic exchange amongst isolates have led to the formation of
national gene pools. We found three outer membrane proteins with atypical
levels of Asian ancestry in American strains, as well as alleles that were
nearly fixed specifically in South American isolates, suggesting a role
for the ethnic makeup of hosts in the colonization of incoming strains.
Our results show that new H. pylori subpopulations can rapidly arise,
spread and adapt during times of demographic flux, and suggest that
differences in transmission ecology between high and low prevalence areas
may substantially affect the composition of bacterial populations.