CagA, VacA And IceA Genotypes Of Helicobacter Pylori Isolated From Children In Shanghai

Objective:To investigate cagA,vacA and iceA genotypes of Helicobacter pylori(Hp) isolated from children suffering from gastric and duodenal diseases in Shanghai area and look for a possible genotype-phenotype correlation.Methods:From May 2007 to January 2008,59 children were diagnosed as Hp infected by endoscopy.Biopsy specimens were taken from their gastric antrum with one for polymerase chain reaction(PCR) for detecting cagA,vacA and iceA genes,one for histological examination and one for enzymelinked immunosorbentassy(ELISA) for detecting the levels of IFN-γand IL-4.Results:Single cagA was detected in 64.9%of isolates.vacA sl/ml and vacA sl/m2 were present in 19.3%and 40.4%of isolates,respectively.iceA1 and iceA2 were found in 63.2%and 19.3%of isolates,respectively.Both iceA alleles were detected in 8.8%of isolates.There was no statistical correlation in genotypes between the gastritis and ulcer group.cagA was detected in 66.7%,52.9%,72.2%of isolates from patient with mild, mild to moderate,moderate chronic gastritis,respectively.vac sl/ml was detected in 19%,11.8%,27.8%of isolates,respectively.vac sl/m2 was detected in 47.6%,29.4%, 38.9%of isolates,respectively.iceA1 was detected in 71.4%,47.1%,72.2%of isolates, respectively.iceA2 was detected in 9.3%,35.3%,16.7%of isolates,respectively.No association was observed between Hp genotypes and the degree of imflammation.No association was observed between Hp genotypes and the mucosal cytokine levels.Conclusion:The cagA~+/vacA s1/m2/ iceA1 was the commonest genotype combination of Hp in the children in this area.No association was observed between Hp genotypes and clinical variables suggesting the potential role of host and environment factors for the development of clinical disease at a later age.