Whole Genome Sequencing Reveals Virulence Potentials of <i>Helicobacter pylori</i> Strain KE21 Isolated from a Kenyan Patient with Gastric Signet Ring Cell Carcinoma
Catherine Mwangi,
Stephen Njoroge,
Evariste Tshibangu-Kabamba,
Zahir Moloo,
Allan Rajula,
Smita Devani,
Takashi Matsumoto,
Kimang’a Nyerere,
Samuel Kariuki,
Gunturu Revathi,
Yoshio Yamaoka
Affiliations
Catherine Mwangi
Department of Medical Microbiology, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya
Stephen Njoroge
Department of Medical Microbiology, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya
Evariste Tshibangu-Kabamba
Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
Zahir Moloo
Department of Pathology and Laboratory Medicine, Aga Khan Hospital University, Nairobi P.O. Box 37002-00100, Kenya
Allan Rajula
Gastroenterology section, Aga Khan Hospital University, Nairobi P.O. Box 37002-00100, Kenya
Smita Devani
Gastroenterology section, Aga Khan Hospital University, Nairobi P.O. Box 37002-00100, Kenya
Takashi Matsumoto
Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
Kimang’a Nyerere
Department of Medical Microbiology, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya
Samuel Kariuki
Kenya Medical Research Institute, Nairobi P.O. Box 20778-00202, Kenya
Gunturu Revathi
Department of Pathology and Laboratory Medicine, Aga Khan Hospital University, Nairobi P.O. Box 37002-00100, Kenya
Yoshio Yamaoka
Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
Helicobacter pylori (H.pylori) infection is etiologically associated with severe diseases including gastric cancer; but its pathogenicity is deeply shaped by the exceptional genomic diversification and geographic variation of the species. The clinical relevance of strains colonizing Africa is still debated. This study aimed to explore genomic features and virulence potentials of H. pylori KE21, a typical African strain isolated from a native Kenyan patient diagnosed with a gastric cancer. A high-quality circular genome assembly of 1,648,327 bp (1590 genes) obtained as a hybrid of Illumina Miseq short reads and Oxford Nanopore MinION long reads, clustered within hpAfrica1 population. This genome revealed a virulome and a mobilome encoding more than hundred features potentiating a successful colonization, persistent infection, and enhanced disease pathogenesis. Furthermore, through an experimental infection of gastric epithelial cell lines, strain KE21 showed the ability to promote interleukin-8 production and to induce cellular alterations resulting from the injection of a functional CagA oncogene protein into the cells. This study shows that strain KE21 is potentially virulent and can trigger oncogenic pathways in gastric epithelial cells. Expended genomic and clinical explorations are required to evaluate the epidemiological importance of H. pylori infection and its putative complications in the study population.
