Characterization of Helicobacter pylori genotypes from Iranian patients with gastric clinical diseases: Predominance of vacA s1a and cagA EPIYA-ABC genotypes

Abstract

ObjectivesHelicobacter pylori is a causative agent of peptic ulcers and associated with gastric cancer. The major virulence factors of this organism are vacA and cagA genes. The vacA comes in a mosaic structure and the cagA become activated through a repetitive motif including glutamine (E), proline (P), isoleucine (I), tyrosine (Y) and alanine (A), shortly be called EPIYA. The aim of this study was to characterize the genotypes and the antibiotics resistance pattern of H. pylori isolates in Iranian patients with chronic gastritis, non-ulcer dyspepsia (NUD) and peptic ulcer disease (PUD). Methods191 biopsy samples were obtained from patients referred to Afzalipour hospital in Kerman, during November 2017 to October 2018 and cultured to isolate H. pylori. Isolates were confirmed as H. pylori using PCR with the 16s rRNA specific primers. Antimicrobial susceptibility testing was performed using the modified disk diffusion method and genotyping was done by PCR using the specific primers for vacA, cagA and glmM. ResultsFrom 191 samples, 63 H. pylori isolates were obtained. These, isolated from patients with chronic active gastritis (73%, n = 46), PUD (9.5%, n = 6) and NUD (17.5%, n = 11). Resistance to metronidazole was 55.5%, while the resistance to clarithromycin was 37%. There was no resistance to furazolidone. The most prevalent virulence gene among our isolates was vacA with 89%, while the prevalence of cagA and glmM genes were 59% and 81% respectively. CagA-EPIYA-ABC was the most prevalent motif in chronic gastritis (83%), PUD (75%), and NUD (61%). CagA-EPIYA-ABCC was more prevalent in NUD cases (23%). ConclusionIn this study there was no statistical significant relation between the gastric diseases and the genotypes of H. pylori. This is the first report of H. pylori isolates genotyping in south east of Iran which indicating a diversity among these isolates.