IHelicobacter pylori: comparison ofDNAfingerprints provides evidence forintrafamilial infection

a highprevalence ofantibodies to Helicobacter pylori hasbeendocumented within families, culture andDNA typing of strains frominfected children andtheir parents hasnotbeenevaluated. Thisstudy aimedto analyse H pylori infection withinfamily groups. Endoscopy, gastric biopsy, and H pylori culture were performed on alleight parents offourchildren whopresented with dyspepsia andwhohada positive H pylori culture. Allbiopsy specimens werecultured on Columbia basedblood agarundermicroaero- philic conditions forfourdays. TheDNA from eachstrain was extracted andelectrophoretic patterns were compared after digestion with restriction endonucleases HaeIII orHindIII. Ribotyping using a biotinylated cDNA probe prepared from16Sand23SrRNAofH pylon NCTC 11638 was alsoused.Sevenofthe parents were positive forH pylorn on urease testing, histology, andon culture. DNA typing showedthesame or a similar strain tobe present inatleast twofamily membersinthree ofthefourfamily groups.Infamily 1,the mother, father, andchild allhadan identical strain; infamily 2,father andsonhadasimilar related strain; father andmother hadthesame strain infamily 3;andallstrains were unique infamily 4.Thesedataprovide evidence foreither intrafamilial cross infection or a common source ofinfection withinfamily groups. (Gut 1993; 34:1348-1350)