Helicobacter pylori Cytotoxin-Associated Gene A (cagA) and Vacuolating Cytotoxin Gene A (vacA) Genotypes in Gastrointestinal Patients From Central Thailand

Introduction The development of diseases associated with Helicobacter pylori (H. pylori) infection is closely linked to its virulence genes, which vary by geographic region. This study aimed to determine the prevalence of H. pylori cytotoxin-associated gene A (cagA) and vacuolating cytotoxin gene A (vacA) genes and their genotypes in patients with gastrointestinal diseases. Methods Patients diagnosed with gastrointestinal disease based on endoscopic findings were recruited for the study. Gastric biopsies were collected to screen for H. pylori infection using polymerase chain reaction (PCR). Subsequently, infected samples were tested for cagA and vacA genes, and their genotypes were analyzed by sequencing. Results Among 250 cases, 56% (140/250) exhibited gastrointestinal diseases. Of these cases, 32.1% (45/140) were infected with H. pylori. Regarding gene detection, 40 (88.9%) samples were positive for cagA, while all samples were positive for vacA. For cagA, the Western type with the ABC pattern was the most prominent. There was a statistically significant association between cagA genotypes and clinical outcomes, with the Western type being more prevalent in gastritis patients. For vacA, there was a high prevalence of the s1 and i1, while the m1 and m2 showed similar prevalence. In our combined analysis, the dominant vacA genotype combinations were s1m1i1 (46.7%). There were no statistical differences between the vacA genotypes and clinical outcomes (P > 0.05). Conclusion This study revealed a high prevalence of H. pylori cagA and vacA genes, but there were variations in their genotypes. A correlation was observed between the Western-type cagA and gastritis; however, no association was found between vacA genotypes and clinical outcomes.