Figure 1

Phylogenetic tree of 20 H. pylori strains based on their well-defined core genes. Well-defined core OGs were used for neighbor-joining method (see Methods). Numbers indicate bootstrap values. Scale bar indicates substitutions per nucleic acid residue (change/nucleotide site). The assignment of population/subpopulation was based on a phylogenetic tree constructed from the concatenated alignment of fragments of seven genes used in the H. pylori MLST database (atpA, efp, mutY, ppa, trpC, ureI and yphC) [18]. Classification of population/subpopulation was as described [10, 19].