Pathogenic potential of Helicobacter pylori strains can explain differences in H. pylori associated diseases rates from Chile and Cuba

Ileana González,Lidice González,Armando Rojas,Jordis Alonso,Jacqueline Romero,Boris L Rodríguez,Ramón Perez Castro,Carlos A Sabatier,Erik Morales,Eliana Valdés,Lino E Torres,Orlando Reyes,Cecilia Cofre

doi:10.3329/bjms.v18i3.41629

Abstract

Background: The prevalence of Helicobacter pylori-related diseases varies geographically and it is partially determined by the virulence of the circulating strains. Cuba and Chile exhibit different gastric cancer rates, on despite of very similar H. pylori infection rates. We determined if differences in the pathogenic potential of H. pylori isolates from Chile and Cuba could explain the disease outcome in each population. Methods: H. pylori isolates from 78 Chilean and 71 Cuban patients were analyzed using PCR for the presence of cagA, babA2, vacA alleles and the pattern of EPIYA motifs. Results: cagA was detected in 94.9 % of Chilean and 64.7 % of Cuban isolates (P < 0.001) and was significantly associated with duodenal ulcer (DU) in Cuba (P < 0.01) but not in Chile. The presence of cagA with multiple EPIYA-C motifs was 18.2 % higher in Chile than in Cuba (P < 0.05). Also, an association was observed between GU (P ≤ 0.05) and premalignant lesions (P < 0.001) with the multiple EPIYA-C motif status of the strains in Chile, but not in Cuba. The prevalence of vacA s2m2 genotype was predominant in Chile (66.7 %), while in Cuba was prevalent the s1m1 genotype (56.8 %); and the last one was significantly associated with the presence of DU in Cuban patients. Conclusions: The cagA status and the EPIYA pattern found in Chilean and Cuban H. pylori clinical isolates partially explain the differences in disease prevalence between both countries. The high proportion of vacA s2m2 genotype in Chile was an unexpected result, needing further studies. Bangladesh Journal of Medical Science Vol.18(3) 2019 p.577-585

Highlights

Helicobacter pylori (H. pylori) is a Gram-negative spiral-shaped bacterium that colonizes the human stomach
From endoscopic observations: 53.5 % of Cuban and 62 % of Chilean patients were diagnosed with gastritis (G), 14.1 % of Cuban and 38 % of Chilean patients had gastric ulcer (GU) and 32.4 % of Cuban patient had duodenal ulcer (DU)
Histological analysis revealed intestinal metaplasia and dysplasia in 39.8 % and 4 % of Chilean patients, respectively. Statistical differences between these populations were found for the appearance of GU, DU and premalignant lesions, in all cases with P < 0.001

Summary

Introduction

Helicobacter pylori (H. pylori) is a Gram-negative spiral-shaped bacterium that colonizes the human stomach. This study aimed to compare the prevalence of H. pylori virulence factors in two specific populations, from two Latin American countries, and their association with H. pylori-association diseases finding Materials and Methods: Patients and samples Gastric biopsy samples were obtained from 200 consecutively H. pylori- infected patients of both genders that undergoing routine upper gastrointestinal endoscopy at Medical and Surgical Research Hospitals, Havana city, Cuba and Regional Hospital of Talca, Maule, Chile.

Objectives

Results

Conclusion