Horizontal gene transfer across closely related bacterial strains

We are writing in response to the recent publication by Saunders et al. [1], where they attempt to characterize horizontal gene transfer (HGT) in the two published genomes of Helicobacter pylori strains. Typically, one might not counter such analyses, given the uncertainties surrounding this topic. However, because of the particular importance of this well-studied species as well as the breach of key principles in this field, we feel obliged to react by this short communication.