Helicobacter pylori virulence factors: relationship between genetic variability and phylogeographic origin

Abstract

Background Helicobacter pylori is a pathogenic bacteria that colonize the gastrointestinal tract from human stomachs and causes diseases including gastritis, peptic ulcers, gastric lymphoma (MALT), and gastric cancer, with a higher prevalence in developing countries. Its high genetic diversity among strains is caused by a high mutation rate, observing virulence factors (VFs) variations in different geographic lineages. This study aimed to postulate the genetic variability associated with virulence factors present in the Helicobacter pylori strains, to identify the relationship of these genes with their phylogeographic origin. Methods The complete genomes of 135 strains available in NCBI, from different population origins, were analyzed using bioinformatics tools, identifying a high rate; as well as reorganization events in 87 virulence factor genes, divided into seven functional groups, to determine changes in position, number of copies, nucleotide identity and size, contrasting them with their geographical lineage and pathogenic phenotype. Results Bioinformatics analyses show a high rate of gene annotation errors in VF. Analysis of genetic variability of VFs shown that there is not a direct relationship between the reorganization and geographic lineage. However, regarding the pathogenic phenotype demonstrated in the analysis of many copies, size, and similarity when dividing the strains that possess and not the cag pathogenicity island (cagPAI), having a higher risk of developing gastritis and peptic ulcer was evidenced. Our data has shown that the analysis of the overall genetic variability of all VFs present in each strain of H. pylori is key information in understanding its pathogenic behavior.

Identification, Genome Sequencing, and Characterizations of Helicobacter pylori Sourced from Pakistan

“…A comprehensive investigation of the complete genetic diversity of H. pylori strains provides crucial information in understanding its VFs, drug resistance, and single-nucleotide polymorphism (SNP) [16][17][18]. Further, presence of specific VFs indicates likelihood of severe disease progression.…”

Antibacterial Activity of Clove Medicinal Plants (Bischofia javanica Blume) Against Cell Damage of Staphylococcus aureus and Salmonella enterica

“…However, they are also potentially dangerous due to changes in their composition when the gut ecosystem undergoes abnormal changes due to antibiotic use, disease, stress, aging, poor eating habits, and lifestyle [3]. Various kinds of pathogenic bacteria that colonize the human digestive system can cause many chronic diseases, such as peptic ulcer disease, gastric lymphoma, obesity, cancer [4].…”