Helicobacter pylori is the etiological agent of chronic gastritis, peptic ulcer, and gastric cancer. The duodenal ulcer-promoting gene dupA, which is located in the plasticity region of the H. pylori genome, is homologous to the virB gene which encodes a type IV secretion protein in Agrobacterium tumefaciens. Studies have shown associations between H. pylori dupA-positive strains and gastroduodenal diseases. However, whether dupA acts as a risk factor or protective factor in these diseases remains unclear. Therefore, in this study, we aimed to verify the presence of the dupA gene in infectious H. pylori strains in the Brazilian mid-west and to investigate its association with the clinical outcomes of patients with dyspepsia. Additionally, the phylogenetic origin of the strains was determined. Gastric biopsies from 117 patients with dyspepsia were analyzed using histological and molecular techniques. The hpx gene (16S rRNA) was used to screen for H. pylori infection, and positive samples were then subjected to dupA gene detection and sequencing. The estimated prevalence of H. pylori infection was 64.1%, with the dupA gene being detected in a high proportion of infectious strains (70.7%). Furthermore, a risk analysis revealed that for women, a dupA-positive H. pylori infection increased the chance of developing gastritis by twofold. The partial dupA sequences from isolated infectious strains in this work are similar to those of strains isolated in westerns countries. This study provides useful insights for understanding the role of the H. pylori dupA gene in disease development.

幽门螺杆菌是慢性胃炎、消化性溃疡和胃癌的病原体。十二指肠溃疡促进基因dupA位于幽门螺杆菌基因组的可塑性区，与编码农杆菌中IV 型分泌蛋白的virB基因同源。研究表明H. pylori dupA阳性菌株与胃十二指肠疾病之间存在关联。然而，dupA在这些疾病中是作为危险因素还是保护因素仍不清楚。因此，在本研究中，我们旨在验证感染性幽门螺杆菌中dupA基因的存在。巴西中西部的菌株，并调查其与消化不良患者临床结果的关系。此外，确定了菌株的系统发育起源。使用组织学和分子技术分析了 117 名消化不良患者的胃活检。使用hpx基因（16S rRNA）筛选H. pylori感染，阳性样本再进行dupA基因检测和测序。H. pylori感染的估计患病率为 64.1%，在高比例的感染菌株 (70.7%) 中检测到dupA基因。此外，风险分析显示，对于女性来说，dupA阳性幽门螺杆菌感染使患胃炎的机会增加了两倍。这项工作中分离的传染性菌株的部分dupA序列与西方国家分离的菌株相似。本研究为了解幽门螺杆菌 dupA基因在疾病发展中的作用提供了有用的见解。