Detection and Genotyping of Helicobacter pylori Gene vacA in Children with Gastroduodenal Diseases and in Adults with Gastric Cancer in Vladivostok

Abstract

Geographical distribution of individual genotypes of Helicobacter pylori, predominance of virulent types in various regions of Russia, particularly in the Prymorye Territory, remains unclear. We examined 115 children with various gastroduodenal pathology and 33 patients with gastric cancer, of which 57.39 and 60% respectively were infected with H. pylori. All samples positive for H. pylori were further analyzed for gene vacA mosaicism. In all clinical subgroups, variants s1 and m1 predominated; the frequency of genotype s1 was significantly increased (1.3-fold) in the group of cancer patients in comparison with the group of children with gastroduodenal pathology. Three variants of allele combination of signaling and middle regions of the vacA gene (s1m1, s1m2, and s2m2) were revealed; s1m1 was the most frequent in both groups. We suggest that this genotype is a marker of complicated course of gastroduodenitis and a factor of gastric cancer development in local population.

Review: Prevalence and dynamics of Helicobacter pylori infection during childhood

“…The cross‐sectional studies on H. pylori infection in symptomatic children as detected by histology are summarized in Figure [references: ] . H. pylori prevalence estimates vary greatly (3%‐76%) with an overall random‐effects regression model estimate of 39% (95% CI: 35%‐43%).…”

“…Among children with gastrointestinal symptoms, rates varied from 7% to 76%, with a cluster of studies, 16/43 (37%), reporting prevalence estimates of 30%‐40%. Three studies in children with gastritis or duodenitis reported a 44% positivity rate in Mexico, 46% in Russia and 20% in China . One study in Europe looked at infection rates in children with gastric or duodenal ulcers, in children <6 years old 13% were infected, in 6‐11‐year‐olds 35% and in 12‐18‐year‐olds 38% were infected .…”