Browsing by Author "Rajula, Allan"

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    Prevalence and Endoscopic Findings of Helicobacter pylori Infection among Dyspeptic Patients in Kenya
    (Scientific Research Publishing, 2020-12) Mwangi, Catherine N.; Njoroge, N. Stephen; Rajula, Allan; Laving, Ahmed; Rose, Kamenwa; Smita, Devani; Andrew, Nyerere; Gunturu, Revathi
    Background: Helicobacter pylori is the most common cause of chronic human infections worldwide with the highest reported prevalence in Africa. It is associated with numerous upper gastrointestinal diseases such as gastritis, peptic ulcers, and gastric cancer. Endoscopic findings in the stomach usually associated with Helicobacter pylori infections include gastritis and gastro- esophageal reflux disease (GERD), however, these findings are suggestive but not diagnostic of Helicobacter pylori infection. Methods: This was a prospective study conducted between January 2018 and February 2019 at the Aga Khan University Hospital where dyspeptic patients scheduled for gastroduodenoscopy were enrolled. These patients were evaluated for Helicobacter pylori infection by rapid urease test, culture and histopathology. Diagnostic findings and patient history collected from medical files were documented and data analyzed. Results: A total of 487 dyspeptic patients undergoing esophagogastroduodenoscopy (EGD) were enrolled in the study and 199 dyspeptic patients were positive for Helicobacter pylori infection. The prevalence was 54.6% in males and 45.4% in females (p = 0.1546. The most common clinical indication and endoscopic findings were heart burn (25.2%) and gastritis (53.7%). Histopathology revealed that 86.1% of the dyspeptic patients had chronic active gastritis (p < 0.005) and 52.8% of them had H. pylori infection. Conclusions: Classical endoscopic findings such as GERD are not always indicative of H. pylori infection as its association with H. pylori infection was not statistically significant in this study.
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    Whole Genome Sequencing Reveals Virulence Potentials of Helicobacter pylori Strain KE21 Isolated from a Kenyan Patient with Gastric Signet Ring Cell Carcinoma
    (MPDI, 2020) Mwangi, Catherine; Njoroge, Stephen; Tshibangu-Kabamba, Evariste; Moloo, Zahir; Rajula, Allan; Devani, Smita; Matsumoto, Takashi; Nyerere, Kimang’a; Kariuki, Samuel; Revathi, Gunturu; Yamaoka, Yoshio
    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.