Intrafamilial Genotyping of Helicobacter pylori from Faecal DNA

Helicobacter pyloriinfection, often acquired in early childhood, is a global cause of undernutrition, gastritis, peptic ulcer disease and gastric carcinoma. This study tested the feasibility of usingH. pylorished in the faeces as a source of DNA for non-invasive epidemiological studies.H. pyloriDNA was chemically recovered and isolated using a specific biotinylated oligonucleotide probe with magnetic capture from 28H. pyloripositive faecal samples obtained from children attending hospital for the investigation of suspectedH. pyloriinfection, together with close family members. Random amplification of polymorphic DNA (RAPD) was subsequently used to discriminate each isolate. 93% of stool samples selected were typeable. Parent, child and sibling samples were compared and similarities determined. Phylogenetic analysis showed thatH. pyloriDNA obtained from the faeces can be used to genotype individual strains, offering a means of studying intrafamilial transfer of this microorganism.