Differences in Virulence Markers betweenHelicobacter pyloriStrains from Iraq and Those from Iran: Potential Importance of Regional Differences inH. pylori-Associated Disease

Abstract

Helicobacter pylori causes peptic ulceration and gastric adenocarcinoma; the latter is common in Iran but not in Iraq. We hypothesized that more virulent H. pylori strains may be found in Iran than in Iraq and so compared established and newly described virulence factors in strains from these countries. We studied 59 unselected dyspeptic patients from Iran and 49 from Iraq. cagA was found in similar proportions of strains from both countries (76% in Iran versus 71% in Iraq) and was significantly associated with peptic ulcer disease in Iraq (P < 0.01) but not in Iran. cagA alleles encoding four or more tyrosine phosphorylation motifs were found in 12% of the Iranian strains but none of the Iraqi strains (P ‫؍‬ 0.02). There were no significant differences in the vacA signal-, middle-, or intermediate-region types between Iranian and Iraqi strains. Among the strains from Iran, vacA genotypes showed no specific peptic ulcer associations, but among the strains from Iraq, vacA i1 strains were associated with gastric ulcer (P < 0.02), mimicking their previously demonstrated association with gastric cancer in Iran. dupA was found in similar proportions of Iranian and Iraqi strains (38% and 32%, respectively) and was associated with peptic ulceration in Iraqi patients (P < 0.01) but not Iranian patients. H. pylori strains from Iraq and Iran possess virulence factors similar to those in Western countries. The presence of cagA with more phosphorylation motifs in Iranian strains may contribute to the higher incidence of gastric cancer. However, the association between strain virulence markers and disease in Iraq but not Iran suggests that other host and environmental factors may be more important in the diseaseprone Iranian population.

Prevalence of EPIYA motifs in Helicobacter pylori strains isolated from patients with gastroduodenal disorders in northern Iran

“…This binding activates SHP-2 and induction of stronger and longer periods of SHP-2 activity, leads to an increased signal transduction, greater morphological damage, and involved in development of gastric cancer. Therefore recent studies indicated prevalence of strains with more than one repeat region (such as ABCC) was 51.1% in Colombia and 33.3% in Italy population (20), also this current study 25.6% but in other recent studies in Iran revealed 3.3% (21) and 12% (24). This discordant as mentioned before, may be due to the high prevalence of gastric cancer and geographical and environmental difference in northern parts of Iran.…”

Detection of cagA and vacA genotypes of Helicobacter pylori isolates from a university hospital in Ankara region, Turkey

“…Such an association has previously been reported, especially in Western isolates (21). However, this relationship could not be determined in strains isolated from Asian countries (22,23). On the other hand, in a current study from Turkey, Karaman et al reported a cagA positivity rate of 65.5% and they also found a significant relationship between cagA status and peptic ulcer disease (17).…”

Pleiotropic Actions of Helicobacter pylori Vacuolating Cytotoxin, VacA

“…The vacA intermediate (i)-region, which encodes part of the p33 domain of VacA, displays sequence variation at the nucleotide level (Rhead et al 2007). i1-type strains, but not i2-type strain, were associated with gastric carcinoma in an Iranian population (Rhead et al 2007;Hussein et al 2008), and were an independent predictor of peptic ulcer disease in an Italian population (Basso et al 2008).…”