Based on genome sequencing and other reports, the closest relative of H. pylori is H. acinonychis, which has been found in stomachs of big predator cats such as lions or cheetahs[31], [33], [44], [48]–[52]. Complete sequencing of H. acinonychis strain Sheeba and comparisons to European and African H. pylori strains exhibited similar core genes and also distinctively different features including an unusually high number of fragmented genes for VacA and outer membrane proteins (OMPs). A host jump from early humans to large felines, probably about 200,000 years ago, was proposed [31]. However, our knowledge of non-pyloriHelicobacter spp. such as H. acinonychis is still very incomplete, as illustrated by a total of only two deposited 16S rRNA sequences (accession numbers AM260522.1 and AF057163.1) for this species. We are interested in identifying novel gastric and extra-gastric Helicobacterspp., and characterising their genetics, bacterial pathogenicity factors and gastric disease-associated processes to better understand mechanisms of bacterial adaptation to host environments and associated health and disease [47]. Here we report on the isolation and detailed molecular characterisation of novel H. acinonychis strains from a Bengal tiger (Panthera tigris tigris).