Objective: To investigate cagA, vacA and iceA genotypes of Helicobacter pylori (H. pylori) isolated from children suffering from gastric and duodenal diseases in Shanghai and to explore a possible genotype-phenotype correlation.
Methods: From May 2007 to January 2008, 59 children were confirmed with Hp infection by gastroscopy. Biopsied specimens were taken from the gastric antrum. cagA, vacA and iceA genes were determined by PCR. The histological changes in the gastric mucosa were evaluated. The levels of IFN-gamma and IL-4 in the gastric mucosa were measured using ELISA.
Results: cagA, vacAs1/m1, vacAs1/m2, iceA1 and iceA2 were found in 65%, 19%, 40%, 63% and 19% of H. pylori strains, respectively. Both iceA1 and iceA2 were detected in 9% of strains. There were no statistical differences in the distribution of various genotypes between the children with chronic gastritis and peptic ulcer. No association was observed between the genotypes and the degree of inflammation of gastric mucosa. There were no significant differences in levels of IFN-gamma and IL-4 in the gastric mucosa infected by different genotypes of H. pylori strains.
Conclusions: cagA/vacAs1/m2/iceA1 may be the commonest genotype combination of H.pylori in children from Shanghai. That there was no association between H.pylori genotypes and clinical variables suggests the potential role of host and environment factors in the development of clinical diseases at a later life.