Characteristics of Helicobacter pylori strains isolated from Mauritanian patients

Helicobacter. 2020 Oct;25(5):e12726. doi: 10.1111/hel.12726. Epub 2020 Jul 19.


Background: Helicobacter pylori (H pylori) is responsible for various diseases including cancer It co-evolved with humans, and human migrations shaped the expansion and the diversity of strains around the world. The risk of developing a disease depends on virulence factors, mainly the cytotoxin-associated gene A protein (CagA). The aim of this study was to determine the cagA status in H pylori strains from Mauritanian patients and to search for a relationship with endoscopic and histologic findings.

Material and methods: H pylori was searched in gastric biopsies taken during endoscopy in patients with gastro-duodenal symptoms. RT-PCR was used for the diagnosis and resistance to clarithromycin. The cagA status was determined with PCR and the EPIYA-cagA polymorphism with sequencing.

Results: At all, 76/78 (97.4%) biopsies were positive. The rate of clarithromycin resistance was 4/76 (5.26%) due to the A2143G mutation, with a mixed population in 2 cases. The cagA gene was present in 23/76 (30.26%) biopsies, and the EPIYA motif was ABC in 21 (91.3%). High bacterial load and inflammation were significantly associated with cagA-positive status (P < .01). Phylogenetic analysis of the glmM and hspA genes highlighted a mixture of African and European genes in strains of H pylori isolated from patients of Moor origin.

Conclusion: We report a high prevalence of H pylori infection in Mauritanian patients, a low rate of clarithromycin resistance (5.26%) and high bacterial load and inflammation associated with cagA-positive status. The phylogenetic analysis highlights the mix of different populations leading to the Moor ethnicity.

Keywords: Helicobacter pylori; cagA gene; EPIYA motif; Mauritania; PCR.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antigens, Bacterial / genetics*
  • Bacterial Proteins / genetics*
  • Child
  • Clarithromycin / pharmacology
  • Drug Resistance, Bacterial / genetics
  • Female
  • Helicobacter Infections / epidemiology
  • Helicobacter Infections / microbiology*
  • Helicobacter pylori* / genetics
  • Helicobacter pylori* / isolation & purification
  • Helicobacter pylori* / pathogenicity
  • Humans
  • Male
  • Mauritania / epidemiology
  • Middle Aged
  • Virulence Factors / genetics*
  • Young Adult


  • Antigens, Bacterial
  • Bacterial Proteins
  • Virulence Factors
  • cagA protein, Helicobacter pylori
  • Clarithromycin