Helicobacter pylori vacA Genotypes in Chronic Gastritis and Gastric Carcinoma Patients from Macau, China

Abstract

Helicobacter pylori is the major triggering factor for gastric carcinoma, but only a small proportion of infected patients develop this disease. Differences in virulence observed among H. pylori strains, namely in the vacuolating cytotoxin vacA gene, may contribute to this discrepancy. Infection with vacA s1, i1 and m1 strains increases the risk for progression of gastric premalignant lesions and for gastric carcinoma. However, in East Asian countries most of the H. pylori strains are vacA s1, regardless of the patients’ clinical status, and the significance of the vacA i1 and m1 genotypes for gastric carcinoma in this geographic area remains to be fully elucidated. The aim of the present study was to investigate this relationship in 290 patients from Macau, China. Using very sensitive and accurate genotyping methods, we detected infection with vacA i1 and with vacA m1 strains in, respectively, 85.2% and 52.6% of the patients that were infected with single genotypes. The prevalence of cagA-positive strains was 87.5%. No significant associations were observed between vacA genotypes or cagA and gastric carcinoma. It is worth noting that 37.5% of the infected patients had coexistence of H. pylori strains with different vacA genotypes. Additional studies directed to other H. pylori virulence factors should be performed to identify high risk patients in East Asia.

Epidemiology of Helicobacter pylori infection

“…They are difficult to detect but should impact the effectiveness of eradication treatment. Multiple infections are very often suspected when virulence genes are characterized . Three articles focused on multiple infections this year.…”

“…Multiple infections are very often suspected when virulence genes are characterized. [6][7][8][9] Three articles focused on multiple infections this year.…”

Mechanisms of the Epithelial–Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer

“…Gastric cancer is one of the most common diseases related to H. pylori infection, responsible for approximately 75% of gastric cancer incidents worldwide [26][27][28][29]. The discrepancy in the severity of gastric cancer is associated with many factors and mechanisms, among which various genotypes of H. pylori strains play a role [30][31][32][33][34][35][36][37][38][39][40]. H. pylori induces other diseases of the alimentary tract, including gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue lymphoma, GERD symptoms, and dyspepsia [41][42][43][44][45][46].…”

Genotyping of the Helicobacter pylori isolates of raw milk and traditional dairy products

“…The s1 type is additional subtyped into s1a, s1b and s1c subtypes, and the m1 into m1a and m1b subtypes. 6,7 The mosaic combination of s and m-region allelic types determines the particular cytotoxin and, consequently, the pathogenicity of the bacterium. Genotyping using vacA virulence marker is considered as one of the best approaches for study of correlations between H. pylori isolates from different samples.…”

“…Genotyping using vacA virulence marker is considered as one of the best approaches for study of correlations between H. pylori isolates from different samples. 6,7 …”