Prevalence of Helicobacter pylori genotypes (vacA, cagA, cagE and virB11) in gastric cancer in Brazilian's patients: an association with histopathological parameters

PURPOSE

To investigate the frequency and the association of vacA alleles, cagA, cagE and virB11 genes of Helicobacter pylori from patients with gastric cancer, considering the clinic histopathological parameters.

METHODS

One hundred and one gastric adenocarcinoma tissues were assessed by PCR to detect H. pylori and vacA alleles, cagA, cagE and virB11.

RESULTS

The distribution of cases according to the presence of the genes studied showed that the group containing vacA s1m1, cagA, cagE and virB11 H. pylori genes was significantly more frequent, followed by the group with at least one marker on the right side and left of the island. They were also present in the early stages and were the most frequent in nearly all histopathological grades.

CONCLUSIONS

This study verified that vacAs1m1 and cag-PAI genes, cagA, cagE and virB11 are important H. pylori markers for gastric cancer development. Also, this study corroborates the importance of cagE and cagA together as cag-PAI marker.

Prevalence of Helicobacter pylori vacA, cagA, cagE, iceA and babA2 genotypes in Thai dyspeptic patients

OBJECTIVES

To investigate the prevalence of the vacA, cagA, cagE, iceA, and babA2 genotypes in Helicobacter pylori strains isolated from Thai dyspeptic patients, and to determine whether any correlation exists between these genotypes and clinical manifestations.

METHODS

Helicobacter pylori was examined in 112 patients (62 with non-ulcer dyspepsia (gastritis), 34 with peptic ulcer disease, and 16 with gastric cancer (GCA)), detected by culture or direct detection from gastric biopsies. Allelic variants of the vacA, cagA, cagE, iceA, and babA2 genotypes were identified by using the polymerase chain reaction.

RESULTS

The positive rates for the vacAs1, vacAs2, cagA, cagE, iceA1, iceA2, and babA2 genes in H. pylori of dyspeptic patients were 100%, 0%, 98.2%, 88.4%, 45.5%, 33.1%, and 92%, respectively. The allelic variant vacAs1m1 was more prevalent (58%) than vacAs1m2 (42%). The cagA and cagE genes were commonly found together (87.5%). The most predominant genotypes were vacAs1m1, cagA, cagE, iceA1, and babA2. The various genes alone or in combination had no statistically significant association with the clinical outcomes (p>0.05).

CONCLUSION

Neither single gene nor combination of vacA, cagA, cagE, iceA, and babA2 genes was significantly helpful in predicting the clinical outcome of H. pylori infection in Thai patients. The high prevalence of these genes in H. pylori isolated from Thai patient groups suggests that H. pylori strains are geographically dependent.

Analysis of the vacA, cagA, cagE, iceA, and babA2 genes in Helicobacter pylori from sixty-one pediatric patients from the Midwestern United States

This study was designed to characterize H. pylori from pediatric gastric biopsy specimens in terms of several genes (vacA, cagA, cagE, iceA1, iceA2, and babA2) proposed to be involved in the pathogenesis of this organism. Many of these genes have been studied in adult H. pylori isolates, however, these genes have not been well characterized in H. pylori from children. Using PCR we observed that 44% of the H. pylori in our biopsies shared two common genotypes (vacA s1b m1, cagA, cagE, iceA2 +/- babA2). While 26% of the H. pylori had unique genotypes. The cag pathogenicity island associated genes, cagA and cagE, were found together in 64% or our H. pylori, while 84% were iceA2 positive. The presence of the babA2 gene has been proposed to be associated with a higher risk of H. pylori related diseases, however, we found that only 36% of our H. pylori contained this gene.