Helicobacter pylori: after the genomes, back to biology.

Abstract

The race to sequence the human genome generated a global emotional wave which escaped the scientific community and involved the media, the politicians, the economic world, and the general public. The sequencing of several bacterial genomes also generated a high interest. A few years after publication of the genomes we are back at the bench, performing ad hoc experiments and asking ourselves what the genomic wave meant and how it changed our lives. The genome of Helicobacter pylori, the bacterium which causes peptic ulcer and gastric cancer, was published back in 1997 (1), and it is very old in genomic terms (H. pylori was the fourth bacterial genome to be published after the one of Haemophilus influenzae, Mycoplasma genitalium, and Methanococcus jannaschii). H. pylori was also the first bacterium for which the genomes of two different strains were determined (2), and the first one for which maps of protein–protein interactions were published (3). In spite of this, our knowledge is still limited and pregenomic experiments are still needed to unravel the secrets of how this bacterium causes disease. A paper describing the first application of signature tagged mutagenesis (STM) to identify virulence factors of H. pylori, published in this issue (4), provides us with an opportunity to think about the biology in the postgenomic era, the role of the pregenomic techniques in general, and also what the new findings mean for H. pylori.