Clinical relevance and distribution of Helicobacter pylori virulence factors in isolates from Chinese patients

Abstract

Background At present, the relationship between virulence factors of Helicobacter pylori ( H. pylori ) and gastrointestinal diseases is still under discussion. This study investigated the association between distinct virulence factors in H. pylori and different gastrointestinal diseases. Methods Gastric biopsy specimens were obtained from 160 patients with different gastrointestinal diseases in China, including 77 patients with chronic gastritis (CG), 36 with peptic ulcer disease (PUD), and 38 with gastric carcinoma (GC). The presence of certain virulence genes was determined by polymerase chain reaction (PCR), and the results were analyzed using chi-squared tests. Results A total of 160 H. pylori strains were successfully isolated from gastric biopsy specimens. Overall, all strains of H. pylori were cagA , cagE positive, and the most common vacA genotypes were s1 (98.8%) and m2 (68.1%). The positive rates of the jhp0562 , jhp0563 , homA , homB , hopQI , and hopQII genes were 99.4%, 32.5%, 33.1%, 71.3%, 100%, and 6.9%, respectively. There was no significant association between these genes and different disease types. The dominant hpy IIIR-positive genotype was detected in 83.1% of the strains, making it significantly more prevalent than the hrgA -positive genotype (P<0.001). Surprisingly, the mixed genotype of hrgA and hpy IIIR was common and accounted for 41.3%. The hrgA -positive strains were more common in GC patients (71.1%) compared to CG patients (50.7%, P<0.05). The mixed genotype was prevalent and accounted for 55.3% and 31.2% of strains from GC and CG patients, respectively. Multivariate analysis showed that the hrgA gene exhibited a positive correlation with GC and increased the risk of GC [odds ratio (OR) =3.606, P<0.05]. In contrast, the presence of hrgA exhibited a negative correlation with CG (OR =0.499, P<0.05). Conclusions These results suggested that the universal presence of cagA , cagE , vacA s1, jhp0562 , homB , and hopQI made it impossible to examine disease-specific associations with any of these virulence factors. In addition, they may synergistically contribute to more virulent strains and severe diseases in China. Furthermore, there was a strong association between the ...

AUF1-mediated inhibition of autophagic lysosomal degradation contributes to CagA stability and Helicobacter pylori -induced inflammation

“…Consistent with previous findings, our study demonstrated an increase in AUF1 expression in both gastric epithelial cells and gastric mucosal tissue of patients with chronic superficial gastritis infected with CagA-positive H. pylori ( Figure 7 ). Although we did not conduct a biopsy typing test for CagA in the gastric mucosa of H. pylori -infected patients, recent studies in China have reported a prevalence of CagA-positive H. pylori strains ranging from 97% to 100%, 56 , 57 suggesting that the majority of H. pylori strains infecting our study participants were CagA-positive. Furthermore, we found that both exogenous CagA and CagA-positive H. pylori infection can induce the translocation of AUF1 from the nucleus to the cytoplasm.…”