LAUSR

Background Helicobacter himalayensis was isolated from Marmota himalayana in the Qinghai-Tibet Plateau, China, and is a new non- H. pylori species, with unclear taxonomy, phylogeny, and pathogenicity . Results A comparative genomic analysis was performed between the H. himalayensis type strain 80(YS1) T and other the genomes of Helicobacter species present in the National Center for Biotechnology Information (NCBI) database to explore the molecular evolution and potential pathogenicity of H. himalayensis . H. himalayensis 80(YS1) T formed a clade with H. cinaedi and H. hepaticus that was phylogenetically distant from H. pylori . The H. himalayensis genome showed extensive collinearity with H. hepaticus and H. cinaedi . However, it also revealed a low degree of genome collinearity with H. pylori . The genome of 80(YS1) T comprised 1,829,936 bp, with a 39.89% GC content, a predicted genomic island, and 1769 genes. Comparatively, H. himalayensis has more genes for functions in “cell wall/membrane/envelope biogenesis” and “coenzyme transport and metabolism” sub-branches than the other compared helicobacters, and its genome contained 42 virulence factors genes, including that encoding cytolethal distending toxin (CDT). Conclusions We characterized the H. himalayensis 80(YS1) T genome, its phylogenetic position, and its potential pathogenicity. However, further understanding of the pathogenesis of this potentially pathogenic bacterium is required, which might help to manage H. himalayensis -induced diseases.