VIRULENCE AND COLONIZATION-ASSOCIATED PROPERTIES OF HELICOBACTER-PYLORI ISOLATED FROM CHILDREN AND ADOLESCENTS

Helicobacter pylori isolates from 32 children and adolescents were cha racterized with respect to putative virulence and colonization-associa ted properties. Only 3 of the subjects had duodenal ulcer, All but 2 o f the remaining 29 had various degrees of chronic gastric inflammation . No significant correlation between degree of inflammation and presen ce of the cag-pathogenicity island, cytotoxin production, vacA alleles associated with cytotoxin expression, and binding ability to the Lewi s(b) (Le(b)) oligosaccharide was found, Only 4 isolates expressed the Le(b)-specific adhesin, of which 3 were also cag region-positive. This is in contrast to adults with gastritis or peptic ulcer disease (or b oth), in whom most of the H. pylori isolates bind Le(b). In an in situ binding assay H, pylori were less able to adhere to gastric surface m ucous cells in biopsies taken from children compared with adults, sugg esting a lower expression of the Le(b) oligosaccharide in the children .