Rapid Characterization of Virulence Determinants in Isolated from Non-Atrophic Gastritis Patients by Next-Generation Sequencing.

is a major human pathogen that causes a wide range of gastrointestinal pathology. Progression of induced gastritis to more severe disease has been found to highly correlate with the array of virulence factors expressed by the pathogen. The objective of this study was twofold: first, to characterize the genetic diversity of strains isolated from 41 non-atrophic gastritis patients in Switzerland, an issue that has not been investigated to date. And second, to assess the prevalence and sequence variation of virulence factors (, , and ) and genes encoding outer membrane proteins (OMPs; , , , , , and ) by whole genome sequencing (WGS) using an Illumina MiSeq platform. WGS identified high genetic diversity in the analyzed strains. Most isolates were assigned to hpEurope (95.0%, 39/41), and the remaining ones (5.0%, 2/41) to hpEastAsia, subpopulation hspEAsia. Analysis of virulence factors revealed that 43.9% of the strains were -positive, and the s1 allele was detected in 56.0% of the isolates. The presence of was found to be significantly associated ( < 0.001) with the presence of s1, and allele 1 as well as expression of . Moreover, we found an association between the grade of gastritis and abundance in the gastric mucosa, respectively and the presence of , s1 and allele 1. Among our 41 gastritis patients, we identified seven patients infected with strains that carried a specific combination of virulence factors (i.e., , s1 allele and allele), recently implicated in the development of more severe gastrointestinal pathology, like peptic ulcer disease and even gastric cancer. To this end, WGS can be employed for rapid and detailed characterization of virulence determinants in , providing valuable insights into the pathogenic capacity of the bacterium. This could ultimately lead to a higher level of personalized treatment and management of patients suffering from associated infections.