Helicobacter felisHelicobacter InfectionsHelicobacterHelicobacter pyloriGastritisGastric MucosaUreaseHelicobacter heilmanniiStomach NeoplasmsStomachMice, Inbred C57BLChronic DiseaseMice, KnockoutHelicobacter hepaticusPeptic UlcerClarithromycinMetronidazoleAmoxicillinDyspepsiaBacterial ProteinsAnti-Ulcer AgentsOmeprazoleAntigens, BacterialStomach DiseasesGastritis, AtrophicBismuthPyloric AntrumStomach UlcerBreath Tests2-PyridinylmethylsulfinylbenzimidazolesAnti-Bacterial AgentsAntibodies, BacterialGastroscopyLansoprazoleDNA, Bacterial