Whole genome sequencing of Helicobacter pylori with same MLST sequence type

Helicobacter pylori, a bacterial stomach pathogen causing gastritis, ulcers and cancer, is known for high genome/epigenome diversity through mutation and recombination. It often infects a human host in the childhood and persists there for the life. One of the hypotheses for its rapid evolution is that it drastically changes their genomes during adaptation to a new host. In the present work, we aimed to understand H. pylori genome microevolution in human familial transmission. We carried out whole genome sequencing of very closely related strains (the same or almost same sequence type in multi-locus sequence typing by seven genes) found in family members in Japan to determine the path of infection and important nucleotide substitutions for infection establishment.