# Helicobacter pylori cagA, vacA and babA2 genotypes and gastroduodenal diseases: a cross-sectional study from the Mekong Delta of Vietnam

## TL;DR

This study examines how specific Helicobacter pylori gene combinations are linked to different stomach and duodenum diseases in Vietnam.

## Contribution

The study identifies a synergistic effect of cagA, babA2, and vacA s1m2 genotypes in increasing the risk of peptic ulcer and gastric precancerous lesions in Vietnamese populations.

## Key findings

- The cagA(+)/babA2(+)/vacAs1m2 combination was associated with peptic ulcer disease in male patients.
- The same genotype combination was linked to gastric precancerous lesions in female patients.
- The cagA(+)/babA2(+)/vacAs1m1 combination was also prevalent among Vietnamese H. pylori strains.

## Abstract

Introduction. The cagA and vacA genes encode the CagA and VacA proteins, which are the two main toxins of Helicobacter pylori. Regardless of whether the illness is benign or malignant, the majority of Asian H. pylori strains are cagA (+) and vacA s1 (vacA signal region 1 allele); hence, these genotypes cannot account for the severity of gastroduodenal disease.

Gap statement. The babA2 gene encodes the important adhesin BabA of H. pylori, which is crucial for persistent colonization and facilitates the translocation of CagA into host gastric epithelial cells. The synergic interaction of toxins, including CagA, VacA and BabA, could significantly contribute to the pathogenesis of H. pylori. The investigation of cagA, vacA and babA2 genes in clinical H. pylori isolates in Asian nations, particularly Vietnam, is insufficient.

Aim. To investigate the cagA, vacA and babA2 genotypes to further understand their synergistic interaction in the development of gastroduodenal disease in Vietnamese populations.

Methodology. A cross-sectional study was conducted on 169 H. pylori strains isolated from patients with gastroduodenal disease. The PCR assays were performed to determine the cagA, vacA and babA2 genotypes on DNA extracted from cultured H. pylori isolates.

Results. The research showed that the percentage of the cagA(+), babA2(+), vacA s1m1 and vacA s1m2 was 87.6%, 73.4%, 52.1% and 44.4%, respectively. The frequencies of cagA(+)/babA2(+)/vacAs1m1 and cagA(+)/babA2(+)/vacAs1m2 combinations were 44.4% and 28.4 %, respectively. The cagA(+)/babA2(+)/vacAs1m2 combination was associated with peptic ulcer disease [adjusted odds ratio (aOR)=5.53, 95 % confidence interval (CI) 1.09–28.16, P=0.039] in male patients and chronic gastritis with precancerous lesions (aOR=5.31, 95 % CI 1.23–22.89, P=0.025) in female patients.

Conclusion. The cagA(+)/babA2(+)/vacAs1m1 and cagA(+)/babA2(+)/vacAs1m2 combinations were found to be quite prevalent among Vietnamese H. pylori strains. The synergistic effect of cagA(+), babA2(+) and vacA s1m2 in increasing the odds of both peptic ulcer disease and gastric precancerous lesions has been observed.